Juniper. Mechanical-Biological-Treatment : A Guide for Decision Makers Processes, Policies and Markets TECHNOLOGY & BUSINESS REVIEW

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1 TECHNOLOGY & BUSINESS REVIEW Mechanical-Biological-Treatment : A Guide for Decision Makers Processes, Policies and Markets Annexe D Process Reviews A-E: ArrowBio Bedminster Biodegma BTA Civic Ecodeco Juniper

2 Mechanical-Biological-Treatment : A Guide for Decision Makers Processes, Policies & Markets Annexe D Process Reviews Published by: Juniper Consultancy Services Ltd, March 2005, Version 1.0 Principal Authors: Egan Archer, BEng, MSc, PhD, AMIChemE; Adam Baddeley, MSc; Alex Klein, BSc, MSc; Joe Schwager, BA, MICM, AMIMC, MCIWM; Kevin Whiting, BEng, PhD, CEng, FIChemE Acknowledgement This project was funded by UK landfill tax credits provided by Sita Environmental Trust (SET) with additional funding from ASSURRE (The Association for the Sustainable Use and Recovery of Resources in Europe) to each of whom we wish to express our appreciation. We also want to thank Dr Gev Eduljee of Sita, Dr Peter White of ASSURRE, Stuart Reynolds of Norfolk Environmental Waste Services and Andy Saunders of SET, who formed a Technical Advisory Committee. Their insight and many helpful comments were invaluable. We wish to place on record our gratitude to the many process developers, site operators and others who provided information for the preparation of this report. In particular we are grateful to the many individuals who facilitated our visits to reference plants to conduct site appraisals. Many process, product, system and company names cited throughout the text are registered marks. In the interests of legibility, each occurrence is not followed by, or. Nevertheless, we wish to acknowledge the rights of the owners of such marks, and the copyright for figures and pictures used in this report. Copyright Statement Juniper Consultancy Services Ltd All rights reserved. This report may not be copied or given, lent or resold, in part or in whole, to any third party without written permission. Specific additional provisions apply to use of the electronic version of this report. We will also always try and meet reasonable requests from those who wish to quote selectively from the data and analysis contained herein in support of their own technical publications. We ask that you agree the basis of such usage with us in advance and that you always reference the source of the material. Juniper is a registered trademark of Juniper Consultancy Services Ltd. Important Note The inclusion of a supplier or proprietary process in this report does not constitute a recommendation as to its performance or suitability. Equally, non-inclusion does not imply that that process is not suitable for certain applications. We welcome information to assist with the preparation of any future editions of this report. The opinions contained herein are offered to the reader as one viewpoint in the continuing debate about how MBT can contribute to a modern integrated waste management system. They are based upon the information that was available to us at the time of publication and may subsequently change. A wide ranging study of this type may contain inaccuracies and non-current information - for which we apologise in advance. We are always pleased to receive updated information or corrections about any of the processes reviewed for possible inclusion in future editions of the report. This Review has been carried out on a completely independent basis. No payment has been or will be accepted from any process company for inclusion of any information or commentary contained herein. As an analyst active in this field, Juniper also provides confidential consulting services to many companies involved in this sector. We have procedures in place to avoid conflicts of interest, to protect confidential data and to provide 3rd parties with dispassionate, independent advice. Disclaimer This report has been prepared by Juniper with all reasonable skill, care and diligence within the Terms of the contract with the client, incorporating our Terms and Conditions of Business. We disclaim any responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party interprets or relies on the report at their own risk.

3 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-38 ARROWBIO ARROWBIO Summary of the process The ArrowBio process utilises a combination of wet pre-processing and mechanical separation to process mixed MSW to produce a suspension of biodegradable materials. The suspension is treated in a two-stage AD process to produce biogas for use in gas engines and a digestate, which is currently being used as a fertiliser in Israel. Type of process being marketed MSW Wet pre-processing & mechanical separation Two stage wet digestion process Digestate for use as fertiliser Fe, Non Fe-metals & baled p lastics Biogas to electricity Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Plant operating on a commercial basis for >1 year Commercial plant Advantages Disadvantages Key advantages & disadvantages process demonstrated on mixed MSW good flexibility to handle various input wastes as a result of the wet pre-processing stage process is a net energy producer via biogas utilisation process, in present configuration, would not meet UK ABPR further bio-stabilisation of the output may be necessary in some EU Member States the existing plant has only operated at half-scale the process will need to manage large quantities of water in a suitable on-site treatment plant Contact details Oaktech Limited, The Flint Glass Works, 64 Jersey Street, Ancoats Urban Village, Manchester M4 6JW UK. Tel: Fax: Key contacts Alex Marshall Marketing Manager alex@oaktech-environmental.com

4 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-39 ARROWBIO Overview D3.38. D3.39. The ArrowBio system is a waste treatment process developed specifically for treating unsorted MSW. An Israeli company, Arrow Ecology Limited, formerly Hydro Power Limited, developed and owns the ArrowBio technology and markets it in the UK and Eire through Oaktech Environmental Limited. Arrow Ecology has been in business since 1975 and is active in building and operating on-site treatment plants for contaminated water, sludges and industrial hazardous waste. The water-based pre-treatment of the waste carried out in the ArrowBio process is unique relative to other pre-treatment processes we have reviewed during this study. The emphasis is on utilising the water content of the waste to aid its separation, transportation and digestion and hence, all of the processing steps are conducted in wet conditions. The company explained that the process was designed to utilise their knowledge and experience in designing and operating sewage water treatment processes and therefore, their aim was to convert the biodegradable fraction of the incoming waste into a suspension that could be handled and treated in a similar fashion to sewage water. D3.40. The process, developed over the last 10 years, is currently operating on a commercial basis at a plant in Tel Aviv, Israel, which was commissioned in January 2003 to treat mixed MSW. The contract for the commercial plant in Tel Aviv was not awarded in an open competitive tender process, but was instead built with the permission of the operators of the waste Transfer Station where it is sited. D3.41. The plant is housed in a partially open building, situated alongside the Transfer Station. It is convenient for waste trucks to be diverted from unloading in the Transfer Station to unload directly into the ArrowBio pre-processing plant. During our visit we observed this direct tipping system in operation. We did not observe any significant dust emissions during our site visit. There were odours discernable but these were typical of the odours associated with a waste management facility handling mixed MSW and could have been produced by the Transfer Station next door. Status of Technology D3.42. The ArrowBio process combines a two-stage wet anaerobic digestion, the core biological step, with a liquid based pre-processing step, which incorporates some conventional mechanical separation technologies. Laboratory scale development of the technology started in 1993 in conjunction with Technion, a leading technical institution in Israel, and by 1996 a pilot scale plant was being operated.

5 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-40 ARROWBIO Figure D23: Photographs of the Tel Aviv plant Source: Juniper (Photograph taken during Juniper site visit). Top photo from Arrow Ecology D3.43. A demonstration plant that processed 10Tpd of unsorted MSW (c. 3,300 Tpa) was operated in Hadera, Israel from 1999 to The commercial plant was commissioned in 2002 and started operating in At the time of our visit, this plant had operated for just over one year at the main waste Transfer Station in Tel Aviv. D3.44. We were informed by Oaktech that Arrow Ecology is in discussions with a number of municipalities about potential projects utilising the ArrowBio technology. Juniper were also informed of agreements to build two 200 Tpd plants in Spain but no further information was made available at the time of writing this review. We are aware that the technology is being seriously considered by potential clients in a number of countries. D3.45. ArrowBio s core process concept is built around a digestion capacity of about 70,000 Tpa of waste utilising two waste pre-treatment lines, but during our visit we observed that only one pre-treatment line has been installed. The company explained that this was because of the size limitations of the present site. The current rated capacity of this implementation of the process is 100 Tpd (c. 35,000 Tpa based on the plant operating at 10 Tph for 10 hours per day). Data provided by the company suggests that the throughput of waste has been progressively increased from about 10Tpd in January 2003 to the current level.

6 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-41 ARROWBIO The Process Figure D24: MSW pre-preparation in the ArrowBio process in Tel Aviv Recycled Water from AD plant Mixed MSW Light materials & suspended solids Shredder Trommel Flotation Tank >100mm <100mm Air Separator Plastics Hydrocrusher Secondary water tank Settling Tank Sediments Sand Filter Sand Dense materials Residue Drum Screen Oversize (>15mm) > Suspension to AD plant <15mm Screen and bag opening Magnetic & Eddy Current Separation Fe-metals Non-Fe metals KEY Recyclables Further Upgrading Residues Source: Juniper analysis of Oaktech s information

7 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-42 ARROWBIO Waste Preparation D3.46. The MSW delivered to the Transfer Station is tipped from the waste trucks directly into a reception chute that opens into a water-filled tank. The waste is passed through a submerged paddle wheel at the head of this tank into the main body of water, which is continually replenished by water recovered from the dewatering of the digestate in downstream screw and filter presses. We were informed that the water recovered is about 20-28% more than that which is needed for the wet pre-processing stage and that the excess water is treated together with leachate from the nearby landfill in an on-site wastewater treatment plant. D3.47. In the pre-processing tank, concurrent flotation, sedimentation and dispersion of the waste materials occur. This results in the separation of the dense fractions of the waste (which sink to the lower part of the tank) from the less dense materials (which collect in the top part). Most of the biodegradable materials disperse to form a suspension of fine solids. Separation of Heavy Materials D3.48. The stream from the bottom of the inlet water tank is removed by a conveyor system and passed through a bag opening system. The company claims that this arrangement prevents batteries in the incoming waste from being destroyed (as compared to using a shredder) and hence lowers the possibility of such materials contaminating the final digestate. D3.49. The materials are then passed through magnetic and eddy current separators to recover ferrous and non-ferrous metals respectively. The remaining materials pass to a secondary water pool. Light materials from this pool are returned to the inlet tank and the denser materials are sent to landfill. D3.50. Additional systems utilising an electro-optical unit and hand-picking conveyer to recover various coloured glass and to remove any batteries and inerts after the recovery of metals have been proposed by Oaktech for future projects. Such systems however are not being used in the Tel Aviv plant and are likely to increase the overall cost of implementing and operating the process. Separation of Lighter Materials D3.51. The lighter materials are removed, along with the dispersed solid suspension, from the top of the pre-inlet tank through a paddle wheel. This overflow stream is passed through a wet shredder and then an inclined trommel. The larger materials collected on the trommel screen are screened via an air suction system, which removes mainly light plastics, which are baled. The company told us that the baled plastics are currently being exported to China, as a revenue stream for about US$100/Tonne (c. 56/Tonne) to make composites. The remaining materials in this stream are passed through a hydrocrusher along with the trommel undersize and sent to a settling tank.

8 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-43 ARROWBIO D3.52. The overflow from the settling tank is pumped to a sand filter and the overflow passed through a drum screen. The sediments from the settling tank, the materials collected in the sand filter and the drum screen oversize are sent to landfill. The fraction passing the drum screen (containing particles <10-15mm) is pumped to the first stage of the two-step anaerobic digestion process. This fraction contains about 3% TS (total solids). The entire waste preparation stage takes about thirty minutes to complete. Anaerobic Digestion D3.53. The digestion process is divided into two stages and carried out in separate digestion tanks (see Figure D25). In the first stage, hydrolysis and acidogenesis processes take place. Degradable waste is first converted to glucose and amino acids and then to fatty acids, hydrogen and acetic acid (acetogenesis). This is discussed in Annexe A. The inflow of fresh suspension to this stage and the outflow of the hydrolysed suspension are continuous with a Hydraulic Retention Time 1, HRT and Solids Retention Time 2, SRT of about four hours. D3.54. The suspension from the first stage is heated to about C (to facilitate mesophilic digestion) and pumped continuously to the second stage reactor. The heating duty is conducted outside the vessel in heat exchangers that use hot water as the heating medium. The water is heated by utilising the hot exhaust gases leaving the on-site gas engine, which is an efficient way of improving the overall energy balance of the plant. The digestion temperature is not sufficient to meet the requirements of the UK ABPR. D3.55. In the second reaction stage, the methanogenesis reactions take place in an Upflow Anaerobic Sludge Blanket (UASB) digester. In this type of system the suspension is introduced from the bottom of the digester, whence it flows upward through a sludge blanket composed of biologically formed granules. Treatment occurs as the suspension comes into contact with the granules. The HRT in this digester is 1-3 days but the average SRT is about days. D3.56. One potentially significant advantage in using this type of digester is the long SRT that can be achieved through recycling undigested particles over a certain size. This allows those materials, which are harder to digest to be broken down and ultimately increases the overall waste digestion efficiency. A second advantage is that the process supplier has considerable experience in designing and operating this type of digester for sewage sludge applications. D3.57. The two digestion stages are operated separately mainly because the optimum conditions, such as ph, are different. While on the one hand undertaking the digestion process in two stages allows each of the stages to be optimised individually, the need for additional process equipment, tanks, pumps etc., could potentially increase capital and operating costs. 1 the time taken to fill the tank with a certain influent flowrate 2 the time the solid materials remain in the tank

9 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-44 ARROWBIO D3.58. The products from this stage are biogas, used in gas engines to generate electricity; water, a portion of which is recycled to the waste pre-preparation tank; and a solid digestate, which we were told is currently utilised as a fertiliser in Israel. Further details about the utilisation of this material are discussed later (see Outputs). Figure D25: Waste digestion in the ArrowBio process in Tel Aviv (continued from Figure D24) Suspension from prepreparation plant 1 st Stage (Hydrolysis & Acidogenesis) Oversize Filter press Hot water for reheating Heat Exchanger Undersize Screen Digestate Liquids to treatment Hot water 2 nd Stage (Methanogenesis) Filter press Biogas Oversize Screen Digestate Water Heat Exchanger Gas Engine Liquids to treatment Exhaust gases to stack Exhaust gases Electricity KEY Recyclables Further upgrading Effluent stream Energy Source: Juniper analysis of Oaktech s information

10 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-45 ARROWBIO Process Performance D3.59. Typical inputs and outputs from the ArrowBio process being operated in Tel Aviv are shown in Figure D26 Figure D26: Typical inputs and outputs from the ArrowBio process operating in Tel Aviv Waste Feed (100%) Biogas to gas engines (9-13%) Pre-preparation & Mechanical Separation Anaerobic Digestion Fe & Non- Fe metals (3-4%) Light plastics (9-17%) Inerts, oversized rejects & other residues (12-14%) Digestate (c. 8-10%) Recycled water (c. 17%) water to treatment (20-28%) Source: Juniper analysis of Oaktech s data D3.60. Based on information summarised in Figure D26, the waste diversion potential was calculated and is summarised in Figure D27. Figure D27: Landfill diversion (by mass) of ArrowBio process at Tel Aviv Diversion Potential Minimum, % Maximum, % Basis of Estimation Percentage of the input waste diverted from landfill min: all residues and digestate to landfill max: residues to landfill only Note: This is total mass diversion not BMW diversion under UK diversion targets. No data is available on the biodegradability of the process streams. Source: Juniper analysis D3.61. Figure D28 is the reported energy balance from the ArrowBio process operating in Tel Aviv. The process is a net energy producer.

11 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-46 ARROWBIO Figure D28: Energy balance for the ArrowBio Process operating in Tel Aviv Power consumption of entire plant ( kWh/t) The ArrowBio Process Heat Output (630kWh/T) Electrical Output (370kWh/T) Source: Oaktech Operability and Availability D3.62. The actual time the ArrowBio facility has operated since it was commissioned and the average measured annual throughput are summarised in Figure D29. Figure D29: Summary of the Tel Aviv plant availability Plant Commissioned: April 2003 Design Capacity: c.35,000 Tpa Status: Plant currently operating Year Average Operational hours Measured Throughput, Tpa Comments April-June 2004 c Not reported Plant modifications carried out in March 2004 Basis: 10 hrs operation per day Source: Juniper analysis of Arrow Ecology data D3.63. The plant seemed to be operating satisfactorily during our visit to the site in June 2004 and we have been told that it has been operating at the rated throughput since then. The reported hours of operation equates to a process availability of approximately 88%, which is satisfactory for a first generation plant of this type. It is not possible to make any comments concerning the reliability or maintainability of the process because of the modifications undertaken in March 2004; none of this new equipment has operated for a sufficient time to prove that the design modifications have been successful or that the equipment has demonstrated acceptable reliability.

12 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-47 ARROWBIO Process Flexibility Input Materials D3.64. The ArrowBio process has so far been demonstrated on mixed MSW. The waste received at the Tel Aviv plant is a mixture of materials; some of which have undergone varying levels of source separation and others that have not undergone any source separation at all. Based on this experience the company is marketing the technology for treating both unsegregated MSW and a number of other unsorted wastes: Unsorted industrial waste from the paper and food industries; Animal manures and agricultural residues; Slaughterhouse wastes; Various industrial sludges; Garden wastes with or without household discards. D3.65. It is our view that the extensive preparation and separation of the waste feed to isolate the biodegradable organic fraction before anaerobic digestion, provides a level of flexibility that makes the system worthy of consideration for a variety of mixed waste feeds. Also, the water-based process concept and the inherent design features of the system allow it to cope with the movement of large quantities of liquids, so it is likely to be particularly suitable for wastes that are in liquid form, either as slurry or as inherently very wet streams. The liquid based approach could also minimise dust dispersion and odour generation throughout the plant (noting that these are also dependent on the provisions made to prevent odorous emissions from the incoming and stored waste as well as the type of building used to house the plant). Process Scale D3.66. The ArrowBio process is designed to be implemented in a modular manner. The typical process module has a capacity of 200 Tpd ( 70,000 Tpa). Although the AD part of the plant in Tel Aviv is designed to handle the biodegradable content of that quantity of mixed waste input, the pre-treatment part of the plant is rated at about 100 Tpd. So the process has not yet been fully operated at the proposed modular scale. D3.67. In a recent expression of interest 1 to build an MSW treatment facility in Toronto, Canada, the company proposed six modules to achieve a capacity of 420,000 Tpa. 1 New and Emerging Technologies, Policies and Practices, Request for Expressions of Interest, No City of Toronto

13 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-48 ARROWBIO Output Materials D3.68. The outputs for the ArrowBio process as operated in Tel Aviv are shown in Figure D30. Figure D30: Outputs based on a plant processing 35,000 Tpa of mixed MSW Outputs Tel Aviv plant, Tpa Application of materials from the Tel Aviv plant Biogas utilised in gas engines Ferrous & Non-ferrous metals can be recycled Inerts (including glass, oversized materials, grit etc.) landfilled Wastewater sent to leachate treatment plant Digestate from AD plant used as a fertiliser in Israel. Will require additional treatment if it is to be applied on soil in the UK. Source: Juniper analysis of Oaktech s data D3.69. Biogas: The measured composition of the biogas produced at Tel Aviv is shown in Figure D31. The company has informed Juniper that the ArrowBio process produces between 125 and 175 m 3 of biogas per tonne of waste input to the plant depending on the waste feed. The calorific value of the biogas typically lies between 27 and 29 MJ/m 3 (Juniper calculation from methane content provided by Oaktech). The Tel Aviv plant is configured to utilise the biogas in a gas engine to produce electricity. The biogas is passed through condensers to remove water before being sent to the on-site gas engine. No further biogas cleaning is carried out at Tel Aviv. Figure D31: Measured biogas composition from the ArrowBio process Constituents Concentration Constituents Concentration CH 4, vol % 81 Vinyl chloride, ppm < 1 CO 2, vol % 17.5 Chloroform, ppm < 1 H 2 S, ppm 90 CCl 4, ppm < 1 Siloxanes NR Chlorobenzene, ppm < 1 O 2, vol % < 0.5 Ethane, ppm < 5 NH 3, ppm 1.3 Butane, ppm < 5 Cl, ppm < 1 Ethylene, ppm < 5 F, ppm <1 Ethanol, ppm < 1 Br, ppm < 1 Isopropyl alcohol, ppm < 1 BTEX, ppm < 1 Acetone, ppm < 1 Mercaptons 0.9 Particulates Reported to be zero Methyl sulphide, ppm < 1 H 2 O NR NR- Not Reported Source: Oaktech

14 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-49 ARROWBIO D3.70. During our site visit we were informed that 20% of the electricity generated (c. 1.1 MW) is used to meet the parasitic load requirements of the plant and the remainder is sent to the local Grid (this is based on the plant processing 35,000 Tpa). A small amount of biogas is also used for heating the UASB reactor. Excess biogas is flared using an enclosed flare. D3.71. D3.72. Digestate: The Company told us that the digestate from the anaerobic digestion plant is being used as a fertiliser or soil improver without any further treatment. They stated that because of the long SRT in the digester, about 80 days, the digestate is fully bio-stabilised. However, no data was provided to confirm the level of bio-stabilisation of the digestate. The final moisture content of the digestate is between 65-70% after pressing. Oaktech informed Juniper that the digestate produced by the Tel Aviv plant is currently taken away by a farmer who pays US$20/Tonne (c. 11/Tonne) but they did not know how this digestate was being used and on which crops. Data on the heavy metal content of this fraction was made available for this review (see Figure D32) along with results from some leaching tests. We were informed that further leaching tests on the digestate are currently being conducted at the University of Manchester in the UK. Figure D32: Metal content of the digestate produced at Tel Aviv Summary of Digestate Analysis Guideline Values Analyte Tested by Arrow Ecology (mg/kg dm) SCC (mg/kg dm) TCLP (mg/litre) Biosolids Grade A (mg/kg dm) PAS 100 (mg/kg dm) AR MR AR MR AR MR Al 4,018 9,772 5,500 5, I.S As <5 <3 <3 <0.05 I.S 20 Ca 37, ,900 36,305 95,870 Cd 1 2 < <0.006 I.S 3 <1.5 Cr <0.005 I.S 100 <100 Cu I.S 100 <200 Fe 5,389 12,380 3,000 6, I.S Hg < I.S <1 K 2,742 5,119 2,100 4, I.S Mg 2,808 6,950 1,700 5, I.S 1 Na 2,276 3,277 3,400 8, I.S Ni I.S 60 <50 P 5,888 25,310 Pb <0.04 I.S 150 <200 S 7,450 17,490 3,600 9,200 Zn 335 1, I.S 200 <400 dm = dry matter AR = Acidogenic Reactor MR = Methanogenic Reactor I.S = Insufficient sample SCC = Specific contaminant concentration (Total Concentration) TCLP = Toxicity Characteristics Leaching Procedure Source: Summary analysis and bio-solids data extracted from data supplied by Oaktech

15 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-50 ARROWBIO D3.73. The results of these tests will give some indication about the potential environmental impact of the digestate if used on soil and whether further treatment is required to reduce such impacts in respect of leachability. Data concerning the biodegradability of this material is needed to determine whether it could be used in certain applications in the UK and Europe. Though we were informed that for this application of the digestate in Israel no further proof of stability is required, similar use of this stream in the UK is unlikely. This is mainly because the current process, as it is being operated in Tel Aviv, does not meet UK ABPR criteria. If the digestate has to be landfilled, it will affect the diversion performance of this system. Further processing of the digestate will affect the process economics D3.74. In order to satisfy aspects of the UK ABPR, Arrow Ecology has proposed postprocessing the de-watered digestate in a pasteurisation/hygienisation unit. In the proposed concept the digestate will be heated in a batch pasteurising unit to 60 0 C and held at this temperature for three hours. No further data was available on this postprocessing option although we are aware that Arrow Ecology has relevant experience in pasteurising sewage sludge. D3.75. The company has indicated that an alternative would be to use the digestate as fuel in boilers and cement kilns, but this has yet to be demonstrated using the material from the ArrowBio process. We are unclear as to the calorific value of the digestate as two very different values (4 and 17 MJ/kg) have been reported from tests conducted on this stream. We sought clarification concerning the real value for the digestate CV but no further information was provided. D3.76. In our view using the digestate as a co-combustion fuel would not be straightforward and would involve several technical and commercial challenges which are discussed in Annexe C. Environmental Impact D3.77. Gas cleaning: No exhaust gas cleaning is carried out at the Tel Aviv plant. The company told Juniper that they are currently conducting an analysis of the gas engine exhaust emissions. These results were not available at the time of writing this review. D3.78. D3.79. Wastewater: The process produces an excess of water even after the recirculation of water to meet process needs. The company explained that after an initial requirement of about 6,000m 3 of water (i.e. c. 170 litres/tpa of waste treated), the system is selfsufficient in water. In the present system at Tel Aviv, this excess wastewater is treated in an on-site wastewater treatment plant before it is sent to sewer. It is reported that the quality of the final liquid effluent is similar to grey water quality in Israel. Typical wastewater quality data from the ArrowBio process is summarised in Figure D33. The advantages of using a wet process are countered by the need to manage the large volume of wastewater produced. The plant in Tel Aviv has access to an existing water treatment plant (at the Transfer Station) which appears suitable for treating the volume and quality of wastewater produced. During our visit to the site it was not possible to

16 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-51 ARROWBIO discuss the contractual arrangement for accessing the water treatment plant. The implication for a new ArrowBio facility would be the need to incorporate a water treatment plant within the overall process design. Figure D33: Typical Wastewater Quality from the ArrowBio Process Components Output from Methanogenic reactors, mg/litre After Polishing, mg/litre Ag <0.05 <0.05 Al As <0.1 <0.1 B Ba Be <0.01 <0.01 Ca Cd <0.01 <0.01 Co Cr Cu <0.05 <0.05 Fe Hg <0.05 <0.05 K Li <0.05 <0.05 Mg Mn 0.2 <0.01 Mo <0.05 <0.05 Na Ni <0.05 <0.05 P 10 <0.5 Pb <0.1 <0.1 S Se <0.05 <0.05 Sr Ti V Zn <0.05 <0.03 ph BOD 66 5 COD TSS Chlorides Source: Oaktech D3.80. Dust & Odours: The company indicated the benefits of utilising a water-based preseparation system in reducing dust and odours. While we expect this to have some benefit in reducing these emissions, additional preventative equipment may be required

17 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-52 ARROWBIO for applications in the EU, such as fully enclosing the waste pre-treatment part of the process. The company proposes that for UK implementation of the technology, odour emissions would be controlled by maintaining negative pressure in the building that houses the process and by passing the air through biofilters. This is an appropriate way to minimise fugitive emissions from waste processing plants, but such systems have not been implemented in the Tel Aviv plant. Footprint & Visual Impact D3.81. A standard 70,000 Tpa module requires ,000 m 2 of land area, which translates to about m 2 /Tpa. The plot area requirement is relatively small compared with a waste management facility based around aerobic composting where large areas of land may be required for compost maturation over periods of months. D3.82. The tallest process items are the Anaerobic Digesters, which are 10-20m in height. The visual impact of the process is similar to that projected by a sewage treatment works or an oil storage depot. The plant in Tel Aviv utilises a low level enclosed flare. Though we did not see this system operating during our visit to the plant, it is unlikely to cause a significant visual impact. Costs D3.83. The capital cost for one process module of 70 ktpa (based on the Tel Aviv plant) reported by the company is 6.9 to 8.1M (c to 12.2M). The company report that the system is currently being operated in Tel Aviv with a gate fee of around US$ per tonne (c /tonne). This figure is low and does not include wastewater treatment as we discussed above. Outstanding Questions D3.84. Some questions remain concerning the leaching characteristics and biodegradability potential of the digestate fraction. This information would help to give some indication about the viability of using this fraction on soil in the UK and other EU Member States and determining whether the material can be placed in a landfill if other market outlets were not available. D3.85. The issues of CO and NOx emissions from the gas engine remain unresolved because data is not yet available from measurements we understand the company is currently undertaking.

18 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-53 ARROWBIO Summary D3.86. The ArrowBio process concept is soundly based and has so far been demonstrated to process mixed MSW. While the reliability and operability of the process have not yet been proven over a sufficient period of time (in respect to changes that were made in March 2004), or at full-scale, the operational and environmental performance to date has been satisfactory and in line with a first generation plant of this type. D3.87. Since the proponents of the technology have not operated it outside Israel, certain elements of the current system will have to be changed or modified in order to minimise environmental and health impacts in accordance with operating Standards in the EU. This is likely to impact upon the cost and delivery time-scale of the system. The process operates with relatively large quantities of water and as a result, the design of new plants may have to include a significant capacity wastewater treatment plant, which would increase costs. D3.88. In common with many other MBT systems, the ArrowBio process, in its present operating configuration, would not meet the requirements of the UK ABPR and this would have to be achieved before the digestate fraction could be applied on soil in the UK. This has implications both for the recycling and landfill diversion performance and for the capital and operating costs of the ArrowBio process. D3.89. The process can be configured to optimise recycling as well as to produce electricity and because of this dual output, it may be an attractive solution in the UK waste management sector. This review was prepared in September 2004 from information provided by the company in late spring A site visit (Tel Aviv, Israel) was conducted on 22 June It was finalised in late October 2004, following further clarification discussions with the process company.

19 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-54 BEDMINSTER BEDMINSTER Summary of the process In the Bedminster process the core biological step is carried out in a long rotating reactor that resembles a cement kiln. The system is being used in several plants around the world to co-compost MSW and sewage sludge on a commercial basis. The main product is a compost-like output (configuration A). The company has also supplied the process to produce a solid fuel, which they call bio-fuel. This configuration (B) has operated at one site in Japan where the solid fuel is converted to ashes and used as a raw material in the manufacture of Eco-cement. Many would view this process as a co-composting technology but it has been implemented in an MBT configuration and is being marketed for such applications in the UK. Type of process being marketed MSW (A) Mechanical postseparation Preprocessing Rotary digester drum Mechanical postseparation Sewage sludge Fe & Non Fe-metals Compost MSW (B) Mechanical postseparation Preprocessing Rotary digester drum Solid Fuel Fe & Non Fe-metals Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Commercial plants Solid fuel plant in Japan Co-composting with sewage sludge Advantages Disadvantages Key advantages & disadvantages proven process that operates at relevant scales in four continents to treat unsegregated MSW synergies in co-locating at a sewage treatment works rapid waste digestion, which can benefit throughput and potentially reduce the size of the plant required process has only operated with sewage sludge in a co-composting mode. This could constrain some projects reference plants have low levels of materials recycling uncertainties regarding the marketability of the compost in the UK. Contact details Oyster Point, Temple Road, Blackrock, Co. Dublin Tel: Fax: Key contact Peter Carey peter.carey@bedminster.com

20 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-55 BEDMINSTER Overview D3.90. The Bedminster composting process was developed over 30 years ago by the Swedish scientist, Eric Eweson, after whom the rotating composting vessel was named the Eweson digester. Although the current owners of the technology make a distinction between their approach and MBT (this distinction is often made because of the mistaken belief that MBT is synonymous with producing a solid fuel and not compostlike output), the process has been used to treat mixed and residual MSW. Recent project proposals for the UK, which we have seen, have included relatively significant mechanical pre-processing elements, alongside the Bedminster digester, to boost the recycling and landfill diversion performance of the process. D3.91. The technology was originally owned by the US company Bedminster Bioconversion Corporation. It was then purchased by Bedminster AB Sweden. When they became insolvent in June 2003, the worldwide rights to the technology were acquired by Oyster Technology Investments. It is now being promoted by the Irish company Bedminster International Limited. The technology is also being promoted by the Australian company Environmental Waste Solutions, who we understand were a licensee of the original owners, Bedminster AB. D3.92. The Bedminster technology typifies the difficulties in assessing whether a particular proprietary system is an MBT process or not. This review also underlines that Mechanical-Biological Treatment, as a waste treatment concept, is a disparate collection of many types of process that aim to meet waste management objectives by the application of biological processing combined with mechanical separation techniques to produce marketable products and maximise the recycling opportunities from MSW 1. Status of Technology D3.93. The Bedminster technology has been operated on a commercial basis in a number of countries. The plants range in scale from a few thousand tonnes per year to a large scale facility treating more than 200,000 Tpa of MSW in Edmonton, Canada. Figure D34 lists the key MSW reference plants utilising this technology. All of these plants (except the plant at Saitama, Japan) co-compost the waste with sewage sludge. D3.94. The Edmonton facility was always planned as a waste processing and recycling facility by the client and has mechanical separation equipment to remove metals and plastics ahead of the composting drums. Juniper visited the Edmonton plant during July 2002 whilst working on a separate project. The Edmonton facility is the largest MSW composting plant in the world that employs the Bedminster technology. Although it is 1 See Annexe A for a more detailed discussion.

21 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-56 BEDMINSTER not described as an MBT plant, in our view it is closely analogous to other MBT plants that we have visited. The plant was built by the Transalta Corporation in 1999 and it processes 193,760 Tpa of MSW and 53,640 Tpa of sewage sludge (dewatered to 25% ds 1 ). D3.95. Bedminster International recently informed us that they supplied one plant in Japan that does not co-process sewage sludge. The Saitama plant uses the Bedminster technology to bio-treat the waste to produce a solid fuel output which is combusted to produce ash. The ash is used as a feed material in a cement making process developed by Taiheiyo Cement. The product is called Eco-cement 2. Figure D34: Selected Bedminster reference plants treating MSW Location Plant capacity Tpd** No. of digesters Treatment Capacity Tpa* Current Status Startup Pinetop-Lakeside, Arizona, USA , Sevierville, Tennessee, USA , Cobb county, Georgia, USA , Sumter County, Florida, USA , Marlborough, Massachusetts, USA Nantucket, Massachusetts, USA , , Port Stephens, Australia , Edmonton, Canada c , Saitama, Japan (Demo. plant) , Cairns, Australia , Perth, Australia , * calculated by Juniper assuming 333 days operation per year. ** The capacity represents the total waste treated (MSW and sludge). All of the Bedminster reference plants utilise MSW and sludge, except the plant in Japan. The colour coding system in Figure 1 denotes plants currently operating ( ) and plants that are under construction, under commissioning or in planning ( ). Source: Juniper analysis of information supplied by Bedminster 1 ds = dry solids 2 T his use in a cement plant is different from the use of SRF directly in cement kilns, which we have discussed in many parts of the report. In Taiheiyo s application, the fuel output is combusted to generate an ash, which is added to the cement making process to improve the pozzalonic properties of the product.

22 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-57 BEDMINSTER The Process Configuration to produce compost D3.96. The process designed to produce compost is based around rapid (three days) in-vessel aerobic digestion stage followed by 3-6 weeks of maturation (depending on the end-use application) in windrows, which are housed in an enclosed aerated hall. Composting takes place at temperatures in the range C in the rotary reactors. It is important to recognise that this accelerated bio-treatment of MSW is achieved because of the addition of sewage sludge to provide bacterial and nitrogen input to the biological processes. To achieve the addition of sewage sludge (or a similar input), which if the plant was not co-located on a sewage works, would require the transport and delivery of relatively large quantities of sludge and might constrain projects on other types of sites in the UK. D3.97. At the Edmonton plant, the mixed MSW feed is extensively pre-sorted to recover metals and various dry recyclables before the digestion stage of the process. This plant also has a refining stage after digestion to remove contaminants from the compost output, which are currently landfilled. The other reference plants carry out much less mechanical sorting and recover lower quantities of recyclables. D3.98. Bedminster informed us that some of their other reference plants, such as Saitama, Japan, are configured with the major mechanical separation occurring after the digestion stage. Thus, they state that they can configure the process in either configuration depending on the specific project requirements. D3.99. The description that follows is that for a plant processing unsegregated MSW to produce compost. D The incoming mixed MSW is visually inspected on a tipping floor to remove unwanted and oversized items. Items such as large pieces of wood are removed, shredded and returned to the tipping floor. D The waste is passed through a bag splitter and then sent to the aerobic digester where it is usually mixed with sewage sludge. Sewage sludge is rich in nitrogen and so enhances the composting process by increasing the level of nutrients in the digester, thereby supporting the growth of bacteria responsible for waste degradation (this is commonly referred to as the adjustment of the C:N ratio). D After the digestion stage the bio-treated output is screened by electromagnetic and eddy-current separators to recover ferrous and non-ferrous metals respectively. It is then screened to remove materials >25mm from the process. These materials consist of non-biodegradables such as plastics. The size fraction that is <25mm is sent for maturation.

23 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-58 BEDMINSTER D After maturation, a further screening stage is used to reject particles >10mm. The particles <10mm form the compost product. Figure D35: The Bedminster process concept for producing compost MSW Unwanted items Waste wood Sludge Shredding Air + water Eddy current separator Non Femetals Bag splitter Aerobic Digester Magnetic separator Primary Screening >25mm Off-gases to biofilter Fe-metals Oversized residues Compost De-stoner <10mm Compost Screening Maturation Sent to landfill >10mm Leachate for process water KEY Recyclables Further Upgrading Emissions Residue Stream Source: Juniper interpretation of Bedminster information D Co-composting with sewage sludge reduces the composting and maturation times, thus increasing the waste throughput and potentially decreasing the plant footprint. It can also help to improve the quality of the resulting compost via higher pathogen destruction because of the elevated temperatures that can be sustained in the digester by the bacterial activity. The relatively high nitrogen, phosphorous and potassium content of the sewage sludge will translate to higher levels of these nutrients in the final compost from the co-composting process, which might be beneficial if this output is to be applied to land. The Edmonton facility has dewatering equipment on-site and sewage sludge is accepted directly from the city-owned wastewater treatment plant. As well as adding the bio-solids to the digestion drums, the liquid centrate 1 is also pumped directly into the drums to achieve the desired moisture content of 48%. 1 centrate is the liquid produced by the centrifuges used to dewater the sludge on a sewage treatment works

24 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-59 BEDMINSTER D Although there is sufficient substrate (organic carbon and energy) and nutrients in MSW for it to be composted alone, the process would be slower, comparatively, because of lower levels of bacterial growth. Figure D36: View of a Bedminster composting reactor Source: Environmental Waste Technologies D The digestion reactors are compartmentalised, horizontal rotating drums operated in a continuous mode. The drums rotate at a speed of about one rpm and are pitched at a slight angle to allow the waste to move from inlet to outlet. The movement of the waste is also aided by internal agitators. The materials being composted are transported from one compartment to the next at the end of a 24 hr period. When one compartment is emptied, the material from the preceding compartment is transferred forwards. The Edmonton plant employs five composting drums; 5 metres in diameter and 74 metres in length. D Air is introduced from the outlet end of the aerobic digester and flows counter-currently to the flow of waste. Thus, the cleanest materials are exposed to the cleanest air, reducing cross-contamination in the reactor. The air also heats up naturally and accumulates moisture as it passes through the process. When it comes into contact with the raw waste in the first compartment, heat is transferred to colder material. The heat transfer also causes, at the same time, moisture in the air to be released. These two processes help to initiate waste degradation. D The exhaust air from the digesters is extracted and sent to biofilters for odour abatement. The air from the maturation hall is also collected and piped through biofilters before being released to the atmosphere. Leachate is re-used as process water. D Each drum can accept up to 150 tonnes of waste in each of its three compartments (i.e. 150 Tpd). After three days of composting the materials are stored for 3-6 weeks in the maturation hall (see Figure D37). The materials are then screened to remove particles >10mm, which are sent for disposal. The <10mm fraction passes through a de-stoner, which also removes glass and other dense inerts from the compost. The heavy

25 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-60 BEDMINSTER materials are sent to landfill or re-used as structure materials in the process and the compost is stored until used. Figure D37: The Edmonton maturation hall Source: City of Edmonton Configuration to produce a solid fuel D Bedminster recently informed us that they are planning to market their technology in a different configuration to produce a solid fuel, which they refer to as a bio-fuel. In this process configuration, co-digestion with sludge is not required. The output from the digester would be passed through various screening stages, depending on the quality of the solid fuel required. However, the bio-treated output from the digester would not be sent for maturation. D We were not provided with any information to assess how this implementation of the Bedminster process has performed since the plant in Saitama started operation in In addition, no mass balance data for this process configuration was made available for this review and no information about the quality of the solid fuel produced. It is not clear whether the process can be operated in this way to produce a solid fuel suitable for co-combustion applications in the UK and Europe and because of the lack of information we could not assess this option further. Process Performance D The company provided us with mass balances for two sizes of plant: 37,500 Tpa and 75,000 Tpa (MSW & sludge in a 2:1 ratio). The mass balance for the 75,000 Tpa facility is shown in Figure D38.

26 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-61 BEDMINSTER Figure D38: Typical mass balance for the Bedminster co-composting process MSW (75%) Unwanted items (c. 3.3%) Waste gases (incl. water vapour) (c %) Sewage sludge (25%) Pre-preparation Aerobic Digestion Moisture (c. 9.5 %) Primary Screening Moisture (c. 4.7 %) Residues (c. 6.3 %) Compost (c. 46%) Final Screening Maturation Leachate used as process water Residues (incl. glass, inerts, etc.) (c. 5.6%) Waste gases (incl. water vapour) (c %) Source: Juniper analysis of information supplied by Bedminster D It should be noted that this balance does not take into account any metals that might have been recovered in the process, though this stream is usually <5-6% by mass of the input to the process. Based on this balance, the waste diversion potential has been calculated and summarised in Figure D39 along with the relevant assumptions that have been made in the calculations. Figure D39: Diversion potential (by mass) of the Bedminster process Diversion Potential Minimum, % Maximum, % Basis of Estimation Percentage of the input waste diverted from landfill Min: residues and compost to landfill. Max: Markets available for compost material. Residues landfilled. Note. This is not BMW diversion under UK diversion targets but total mass diversion Source: Juniper analysis D The information in Figure D38 was provided as an illustration by Bedminster and thus contrasts with the mass balance reported for the Edmonton facility (see Figure D40).

27 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-62 BEDMINSTER Figure D40: Annual inputs & outputs for the Edmonton facility (2002 estimates) Material Tonnes per year % of input material INPUTS: MSW 196, Sewage sludge (25% ds) 53, Total inputs 250, OUTPUTS: Compost 71, Recyclables Loss of mass 2 79, Residues 98, Total outputs 250, includes ferrous metals recovered by the post-composting magnetic separator 2 calculated by subtracting compost output, recyclables and residues from total inputs. Loss of mass is attributed to loss of moisture and CO 2 Source: City of Edmonton Energy Consumption D In recent proposals the energy consumption of the Bedminster process, as shown in Figure D35, is given as 18,000 to 24,000 MWh per annum for facilities with capacities 150,000 to 200,000 Tpa. This translates into an energy consumption of 0.12 MWh/Tonne. Output Materials D Figure D41 lists the products and the quantities of each output, as described in Figure D38, that would be produced in a 75,000 Tpa plant. Figure D41: Products based on plant processing 75,000 Tpa MSW & sludge (based on Figure D38) Products Outputs as is described in Figure D48, Tpa Application Waste gases & moisture c. 29,025 to bio-filtration before discharge Residues (plastic, glass, inerts, oversizes etc.) c. 11,400 may be recyclable but landfill most likely Compost c. 34,500 market required or landfill Wastewater zero reported * recycled within process * Note: there must be a purge to prevent build up of contaminants Source: Juniper analysis of Bedminster s data

28 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-63 BEDMINSTER D Compost : Bedminster provided data (Figure D42) with respect to the quality of compost in relation to the level of contamination with respect to selected heavy metals and visible impurities. This information provides a guide of the typical contamination that could be expected but it cannot be compared with existing standards, such as the UK PAS 100; particularly as unsegregated MSW could contain elements and compounds that are not specified by this standard. The use of relatively significant amounts of sewage sludge will also create uncertainty concerning this data. Figure D42: Quality of compost produced in the Bedminster co-composting process Contaminant Bedminster compost (mg/kg) Cadmium (Cd) 0.37 Chromium (Cr) 11.5 Copper (Cu) 90.0 Mercury (Hg) 0.31 Nickel (Ni) 7.0 Lead (Pb) 11.0 Zinc (Zn) Impurities >2mm <0.5% total contaminants Normalised to 30% (by weight) organic carbon Source: Sustainable Environmental Solutions Ltd D As previously explained, compost is the main output from the current Bedminster processes. At the time of Juniper s visit to the Edmonton plant, the Albertan authorities only allowed the compost produced to be used for contaminated land and mine reclamation projects. D In a UK context, compost arising from a mixed MSW feedstock would not be granted PAS 100 accreditation. Because currently there are no statutory regulations in place that would prohibit the use of this material in the UK (whether or not it meets PAS limits), its utilisation would depend entirely on market acceptance. The use of the compost in the UK will also depend on whether the process meets the UK ABPR. The specific configuration and operation (compartmentalised, uni-directional flow) of the rotary digester may offer some processing benefits in an ABPR context. D In some other European countries the situation is different. In Germany and Austria for example, statutory regulations are in place that would prohibit compost derived from a mixed MSW feedstock from being used as compost. Further discussion on regulatory and market constraints to utilise compost derived from a mixed MSW feedstock are discussed in more detail in Annexe B and Annexe C respectively. D Solid fuel : No data was made available for us to assess the solid fuel process option being marketed by Bedminster. In light of the many challenges in using waste-derived solid fuels as a co-fuel, which we have discussed in Annexe C, actual data will be required to satisfy UK clients of the viability of this approach.

29 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-64 BEDMINSTER Environmental Impact D Gas cleaning: All waste gases from the process and the plant are captured and eventually piped to a separate building which houses the biofilter. This is used to abate odours and other gas phase contaminants. No further information was provided for us to assess how adequate these measures have been in abating odours when used in a cocomposting configuration. D Co-composting with sewage sludge can give rise to significant odours. We are aware of a number of plants that have encountered such problems, and we understand that this applies to some facilities utilising the Bedminster co-composting technology. The process design will have to include adequate measures to minimise odours associated with the storage and conveying of sludge. Health and Safety issues related to the storage and usage of sludges will also have to be addressed. The Edmonton facility extracts all process air from the receiving building, composting drums and the aeration hall and passes it through a cooling chamber and ammonia scrubber prior to the biofilter system. D When the process is configured to make a solid fuel, it would not co-digest sludge. In this case, the issues of odours relating to the handling, storage and use of sludges would not apply. D Wastewater: The process is designed to re-use all of the leachate from maturation as process water; however a purge will be necessary to avoid a rise in the concentration of harmful contaminants. The company stated that the liquids from the reception hall would be collected and treated or re-used as process water. If the liquid run-off is re-used in the composting process, this arrangement will have to be compliant with UK ABPR requirements if the compost output is considered for use on soil in the UK. Footprint & Visual Impact D The configuration of the rotary digesters (see Figure D36) means that the Bedminster system can be constructed with a low building profile. The company informed us that the land-take to implement the Bedminster process would be site specific and hence declined to provide this information for this review. D The Edmonton plant (see Figure D43) has a facility footprint of approximately 40,500m 2, which comprises: the receiving building; tipping floor; five aerobic digestion drums; primary screening area; aeration (maturation) hall; secondary screening area;

30 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-65 BEDMINSTER biofilters; and, an office building and car parking. D The compost maturation and storage area, which can accommodate 112,000 Tonnes of compost, accounts for 80% of the required footprint. The land required by the Edmonton plant equates to 0.16m 2 /Tpa of waste processed. Figure D43: Aerial view of the Edmonton composting plant Rotary aerobic digesters Waste reception building Source: City of Edmonton Costs D No cost information was provided by Bedminster for this review. D Transalta privately financed the Edmonton facility and the original capital cost, excluding land purchase, was reported to be approximately CAN$100 million ( 44.6 million) 1. The City of Edmonton purchased the facility from Transalta in 2001 for a reported CAN$96 million ( 42.9 million). The City reported operation and maintenance, and debt servicing costs of approximately CAN$17 million per year ( 7.6 million/year), which equates to a waste treatment cost of CAN$70 per Tonne ( 31.25/Tonne). 1 1 = CAN$2.24

31 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-66 BEDMINSTER Outstanding Questions D The operating reference plants do not recover a significant quantity of recyclables even though the waste input is mixed MSW. The ability of Bedminster to design and implement complex mechanical sorting technologies is unproven. D It is unclear how Bedminster intend to manage the requirement for the supply of sewage sludge to provide the necessary biological environment within the digestion drums to take advantage of the short residence time to produce a satisfactorily bio-treated product. D No process emissions data was provided for this review, nor did the company explain how the increased odour emissions caused by the handling of sewage sludge would be managed. D No data (mass and energy balances, solid fuel composition) was provided for this review about the bio-fuel configuration, which the company is planning to promote. D It is unclear whether Bedminster International intends to change their marketing strategy for the UK by offering the solid fuel configuration preferentially to the standard compost-like output variant, the quality of which from an unsegregated MSW feedstock is questionable. It is not possible to assess whether the Bedminster process could produce a solid fuel product that would be acceptable to potential co-combustion clients since the Japanese application is a relatively unique application which is probably capable of accepting a greater level of contamination in the fuel product than other co-combustion applications. Summary D The Bedminster process is well known internationally within the waste management industry. There are a relatively large number of facilities in operation in four different continents. D Most of the facilities are designed and operated to produce compost for application to land. One plant in Japan utilises the solid output as a fuel, which is combusted and the ashes are used as a raw material in a specific cement making process (Taiheiyo Cement Eco-cement ). D In common with other MBT systems producing a bio-treated output for use on soil, viable market outlets will have to be established for UK implementation of the process. For this implementation, the process will also have to meet the UK ABPR requirements, which may increase the capital and operating costs compared with the costs of other Bedminster projects. D The technology is proven in the co-composting configuration, which requires sewage sludge to help achieve the relatively rapid rate of composting (three days). While we

32 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-67 BEDMINSTER have highlighted some of the issues that can arise when using sewage sludge, the cocomposting of sludge can have a beneficial effect on the quality of the compost output with respect to nutrient content. However, the degree of contamination derived from an unsegregated MSW feedstock relative to similar outputs from other plants composting MSW alone could not be assessed. D Co-locating the plant within or adjacent to a sewage works could be an opportunity to utilise existing infrastructure and minimise the overall impact of waste treatment. D The process may require a significant land-take, as demonstrated by the Edmonton facility, with 80% of the land required for compost maturation and storage. D We understand that the bio-fuel configuration is now being promoted by Bedminster but this process is significantly less proven. While the flexibility in approach could be advantageous, actual data about the operational reliability of the bio-fuel configuration and the composition of the solid fuel produced will be required to satisfy UK clients of the viability of this approach, particularly in the context of uncertain markets for such products. This review was prepared in November 2004 from information provided by Bedminster International and from a number of other public domain sources. Information obtained from a site visit conducted in 2002 to the largest plant using the Bedminster technology was also used in compiling this review. The company provided further information in January The review was finalised in February 2005, following further clarification discussions with Bedminster International.

33 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-68 BIODEGMA BIODEGMA Summary of the process Biodegma utilises a composting process to treat a fine fraction (<80mm) derived from MSW. Biodegma uses compost modules, which are roofed with a semipermeable membrane, which is claimed to reduce the environmental impact of the technology. The process is currently configured to produce a bio-stabilised output and RDF. Type of process being marketed MSW Mechanical preparation Covered composting Screening & refining Fe & RDF Bio-stabilised solids metals & RDF Note: This shows the concept currently being promoted, which is different to that being operated at the company s two reference plants. Commercial status on MSW feedstock No plant yet built Pilot plant Demonstrator plant Commercial plants Advantages Disadvantages Key advantages & disadvantages process has operated commercially at a relevant scale on MSW relatively simple composting units that can be implemented without major civil works flexibility in how the process can be configured for different client requirements the process has not yet been configured to maximise recycling. the process will be a net energy user. Contact details Biodegma GmbH, Martin-Luther-Str. 26, D Ludwigsburg, Germany Tel: Fax: Web: Key contacts Ralph Müller Managing Director rm@biodegma.de

34 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-69 BIODEGMA Overview D The Biodegma MBT process has been developed by the company BIODEGMA Gesellschaft für umwelttechnische Anlagen und Verfahren mbh, based in Stuttgart, Germany. The composting technology, which is at the heart of the MBT process, is Biodegma s core business. The company is privately owned by the company s three Managing Directors plus some other shareholders (who also have shares in the company BEM Umweltservice GmbH, which provides financial and operational support for waste treatment facilities, with a focus on biological treatment and composting). D The Biodegma technology is being marketed in the UK and Eire by Agrivert Limited, which has an exclusive licence for these countries. Agrivert is mainly active in wastewater treatment projects in the UK, recycling bio-solids for use in the agricultural sector. They also provide environmental management services. D The Biodegma technology was being promoted by the German waste management company Umweltschutz Nord, but this company has since ceased trading. D Biodegma has been active in biological waste treatment since the early 1990 s. Their composting system utilises semi-permeable membranes, supplied by Gore, to cover the composting tunnels. Although such types of membranes have been used to directly cover compost heaps, the Biodegma application is unique (see Figure D44). Figure D44: Biodegma s composting tunnels at the Pößneck reference plant in Germany Semi-permeable membrane Source: Juniper (Photograph taken during Juniper s site visit)

35 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-70 BIODEGMA Status of Technology D The MBT process is currently operating at two plants in Germany to treat residual municipal wastes. A list of Biodegma s MBT plants is shown in Figure D45 Figure D45: Biodegma s reference plants treating residual MSW Location Plant Capacity, Tpa Current Status Startup Biberach, Germany 37, Pößneck, Germany 50,000 residual MSW & 35,000 bulky waste 1999 Neumünster, Germany 200, Schwabisch, Fumind, Germany 70, The colour coding system in Figure D45 denotes plants currently operating ( ) and plants that are under construction, under commissioning or in planning ( ). Source: Juniper analysis of Biodegma s information D The plant at Pößneck is a relatively simple construction and, when we visited the facility, we noted that it was very compact for the amount of waste it is designed to process. The bio-stabilised output from this plant does not currently meet the German AT4 standard for stability of such materials and as such, the composting time is shorter (4-5 weeks), which would correspondingly increase throughput. We were informed during our site visit that the process will need to meet the AT4 standard by June 2005 if the Pößneck facility continues to send the output from the composting plant to landfill. D The plant was processing waste when we visited and was receiving both residual MSW and bulky commercial waste, which were being handled in separate pre-processing lines. None of these lines recovered metals from the waste stream. The bio-stabilised output from the composting plant is being sent to landfill without further treatment, hence, the process in its current configuration does not maximise the recovery of recyclables. D We understand from our conversations with Biodegma that the plant at Biberach includes a weeks maturation period, after the initial 4-5 weeks intensive composting, in order to produce a more stable bio-stabilised output material, which is also landfilled. At Biberach, the fraction removed prior to composting is also landfilled. D The plant planned for Neumünster will produce RDF, which the operators plan to combust in a nearby fluidised bed facility being constructed specifically for this application. We gathered that the German utility RWE is involved with the Neumünster project and we were informed by Nehlsen (see Nehlsen review) that they will also utilise this facility (Biodegma s MBT plus the combustor) to process waste from Flensburg, Germany.

36 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-71 BIODEGMA The Process D At Pößneck the incoming residual waste is shredded to particle sizes <250mm. This shredded residual waste is screened using a trommel to separate materials at a size cut of about 80mm. The screen oversize (>80mm) is sent directly to containers. We were informed that these containers are transported off-site and the materials separated further before being used as RDF. We were not provided with any further information about the usage of this stream nor its composition and therefore we are unable to comment on the viability of this outlet. Figure D46: Process as operated at Pößneck, Germany Residual MSW Shredder <250mm Trommel >80mm <80mm Transported offsite for further treatment Sent to landfill Water Mixer Composting Tunnels To biofilter Off-gases Wastewater To off-site water treatment plant KEY Recyclables Further upgrading Effluent Stream Residue Stream Source: Juniper analysis of Biodegma s information D The fraction that is less than 80mm is mixed with water in an auger system and then fed to the composting tunnels by a mechanical loader where it is composted for 4-5 weeks. The output from the composting plant is sent to landfill as bio-stabilised material. D The off-gases from the tunnel composting process are piped to a biofilter before being emitted to atmosphere. This facility may have to be upgraded to manage the off-gases in accordance with the requirements of the German 30BImSchV. It was not apparent whether there were plans to upgrade this facility with the necessary thermal off-gas treatment system in the near future.

37 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-72 BIODEGMA D D Wastewater from the plant (leachate from the composting plant and waste reception area) is transported off-site by tankers to a nearby sewage treatment facility, which also treats the leachate from the nearby landfill. The plant currently being constructed in Neumünster will be configured differently to the Pößneck plant. The main aim of this new plant will be to produce an RDF for combustion. The plant is designed to recover metals and to remove some contamination from the bio-stabilised fraction (composted for 4-5 weeks) before it is also sent for utilisation as RDF. D The Neumünster plant will also be configured with a thermal system to treat the offgases from the process. A schematic of the design for Neumünster is shown in Figure D47. Figure D47: Biodegma s process design for Neumünster, Germany Residual MSW Shredder < mm Magnetic separator Eddy current separator Shredder Trommel > 80mm Femetals Non Femetals < 80mm < 80mm Off-gases to thermal oxidiser To fluidised bed incinerator Mixer Biological Treatment Tunnels Trommel Screen 40-80mm Leachate < 12mm 12-40mm Light fraction Recycled water Washing Density sorting Water Sand to landfill Heavy inerts to landfill KEY Recyclables Further upgrading Effluent Stream Residue Stream Source: Juniper analysis of Biodegma s information

38 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-73 BIODEGMA D Agrivert provided us with a description of an MBT system for managing MSW in the UK. The process is similar in many respects to that proposed for Neumünster, but will include operating procedures to comply with the UK ABPR. The waste will be composted for eight weeks and the bio-stabilised output is proposed to be utilised on soil; unlike in the Neumünster design. Agrivert indicated that the process should recover about 35% of the input as a bio-stabilised output along with a significant amount of RDF separated in the pre-processing part of the process. Process Performance D Although we have not been provided with the relevant data, the total mass diversion from landfill at Pößneck and Biberach is likely to be low. An indicative mass balance provided by Biodegma for a 100,000 Tpa plant configured to maximise recycling is provided in Figure D48. The mass diversion potential of such a system, which is relevant to the UK application of the Biodegma technology, has been calculated and summarised in Figure D49. Figure D48: Indicative mass balance for a 100,000 Tpa Biodegma MBT plant Residual MSW (85%) Bulky wastes (15%) Pre-preparation Rejects (5%) Make-up water Waste gases (incl. water vapour) (23%) Oversized Fraction (>80mm) Metals Separation Composting Process Waste water to be recycled Fe & non-fe metals (5%) Screening & Refining Shredding RDF (40%) Inerts (10%) Light plastics & film (5 %) Bio-stabilised output (12 %) Source: Juniper analysis of Biodegma s information

39 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-74 BIODEGMA Figure D49: Diversion potential of Biodegma s process based on the Pößneck plant Diversion Potential Minimum, % Maximum, % Basis of Estimation Percentage of the input waste diverted from landfill Min: rejects to landfill, inerts to landfill, biostabilised output to landfill, light plastics to landfill, RDF to landfill Max: rejects to landfill, inerts to landfill Note: This is total mass diversion not BMW diversion under UK diversion targets. No data is available on the biodegradability of the process streams. Source: Juniper analysis Energy Balance D No data was made available for this review. The process will be a net consumer of electrical power because of the use of rotating equipment (trommels) and a shredder. Operability and Availability D The Biberach plant started operating over six years ago, while Pößneck commenced operation over four years ago. We were not provided with actual plant availability data for this review. However, we were informed by Biodegma that the waste throughput at Pößneck has decreased since the plant first started operation but that this was due to the reduction in waste going to the plant. Process Flexibility Input Materials D The Biodegma process has so far been demonstrated on residual MSW. The technology has also been extensively utilised for treating source segregated green waste and kitchen waste (biowaste) since A list of some of Biodegma s non-msw reference plants is given in Figure D50. D The Biodegma system is being marketed in the UK by Agrivert to treat unsorted MSW, source separated MSW and green waste. Agrivert is proposing to treat unsorted MSW for eight weeks in two stages (for ABPR compliance). For treating source segregated and green wastes, a four week composting step is proposed followed by four weeks maturation in open windrows. D The process currently in use has been widely used to treat source segregated wastes, but it has only been configured with rudimentary pre-processing when treating MSW (see Figure D46). Additional equipment would be required to maximise recycling from an MSW input and this has been incorporated in the design for Neumünster and future designs of the Biodegma technology.

40 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-75 BIODEGMA Figure D50: Selected Biodegma references treating segregated kitchen/green wastes Location Plant Capacity, Tpa Current Status Startup Marbach, Germany 15, Bamberg, Germany 15, Pfaffenhofen, Germany 6, Hartmannsdorf, Germany 15, Altenburg, Germany 8, Burgdorf, Germany 20, Schönau, Germany 10, Obersontheim, Germany 25, Schweinberg, Germany 35, Otzbach, Germany 40, Ormesheim, Germany 20, Karlskrona, Sweden 9, Helsingborg, Sweden 8, Örebro, Sweden 8, Tampere, Finland 12, Lulea, Sweden 12, The colour coding system denotes plants currently operating ( ), plants that are under construction, under commissioning or in planning ( ) and plants that have stopped or are no longer being built ( ). Source: Juniper analysis of Biodegma s information Process Scale D Biodegma s MBT reference plants have operated at 37,000 Tpa and 85,000 Tpa. The planned facility at Neumünster is designed to process 200,000 Tpa of residual MSW. D Figure D51 lists the number of tunnels and plant capacities for Biberach, Pößneck and Neumünster. Figure D51: Relevant features of the composting tunnels at Biodegma s reference plants Location Plant Capacity, Tpa Number of Tunnels Tunnel dimensions (L W) Biberach, Germany 37, m 6.5 m Pößneck, Germany 50,000 residual MSW 20 21m 6.5 m Neumünster, Germany 200, m 6.5 m Source: Juniper s representation of Biodegma s information

41 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-76 BIODEGMA D The tunnels implemented so far are of the same design. The tunnels proposed for Neumünster have been scaled-up in length. This change is unlikely, in our view, to significantly affect the composting process, provided that the necessary fresh air injection and removal systems are designed for the higher duty. By increasing the capacity of the process in a modular fashion, scale-up risks are minimised. Figure D52: An opened tunnel at Pößneck Source: Juniper (Photograph taken by Juniper during site visit) Output Materials D The outputs from the Biodegma process based on the indicative mass balance provided in Figure D48 are shown in Figure D53. Figure D53: Products based on plant processing 100,000 Tpa MSW (see Figure D48) Products Tpa Application Ferrous & Non-ferrous metals 5,000 can be recycled Inerts 10,000 may be recyclable but landfill most likely RDF 40,000 could be used as a fuel or landfilled Light plastic and foil 5,000 could be used as fuel or recycled Bio-stabilised output 12,000 disposal to landfill Waste gases (including H 2 O vapour) 22,000 to thermal oxidation or biofilter Source: Juniper analysis of data supplied by Biodegma

42 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-77 BIODEGMA D RDF: The largest output is RDF. We have not been provided with more information about the composition of this stream from Pößneck or Biberach, but during our site visit at Pößneck we observed that the RDF stream appeared to be similar to RDF we have seen at other MBT facilities. However, the material produced on the day of our visit contained visible fragments of metal and glass contamination. Both plants have relatively basic pre-processing systems and are therefore less likely to produce a good quality RDF. The newer design planned for Neumünster will have more extensive preprocessing to produce a less contaminated material and one of an adequate size for combusting in a fluidised bed. In our opinion, a fluidised bed combustor is an appropriate method of processing this light, high CV output. The CV of the RDF is reported to range from MJ/kg with a density of 300 kg/m 3 and a moisture content of 25-30%. D D Bio-stabilised output: If the technology is implemented in the UK, Agrivert plans to use the bio-stabilised output in agriculture and land remediation. To meet the UK ABPR it is proposed that for UK based projects a second set of modules would be used to compost the materials for a further four weeks in order to separate the clean and dirty parts of the process, thereby complying with some of the procedures required by the ABPR regulations. A maturation stage is also proposed. Further steps to prevent crosscontamination and to provide the treatment conditions to ensure that the regulatory requirements are met have also been proposed, but none of these have yet been implemented at a commercial plant using the Biodegma technology. Meeting the ABPR is likely to significantly increase capital cost per tonne of waste treated, because larger facilities (i.e. more modules) would be needed to accommodate the longer treatment time. This would also have a knock-on effect on the land-take and operational costs. No additional data on the composition of the bio-stabilised output was made available to us. This is not surprising as this output from the two operating reference plants is presently landfilled. This output from both plants does not meet German AT4 standards as has already been discussed elsewhere in this review. Environmental Impact Gas cleaning, Odour & Dust Abatement: D Biodegma s commercial plants in Germany currently utilise bio-filters to minimise the emissions to atmosphere. The design for the Neumünster plant incorporates a thermal off-gas treatment system. It is still unclear whether this type of treatment could be required when implementing the technology in the UK in the future (to meet potential BAT requirements under IPPC). If it were necessary, implementation and operating costs would increase. Incorporating thermal off-gas treatment may also adversely affect public perceptions and the gaining of planning permissions because of the higher visual impact associated with the stack and the fact that a thermal process was being used onsite. D The composting system uses steel modules roofed with the patented semi-permeable membrane which, it is claimed, prevents water ingress but allows the egress of very fine

43 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-78 BIODEGMA water vapour aerosols, thus helping to control the humidity in the tunnels. It is also claimed that the membrane minimises the release of odour and bio-aerosols. While we did not detect any significant odours while visiting the plant we could not determine whether this was because of the design of the tunnels or the fact that the tunnels were not in an enclosed structure (see Figure D44). D In one study 1 carried out in Germany on membranes (which included those used by Biodegma) it was shown that there was a reduction of odorous emissions when compared with open windrow systems. The results were comparable to the exhaust from a properly functioning bio-filter. The study also concluded that the membranes reduced the emissions of bio-aerosols compared to open windrows. D It is therefore likely that the membrane covers used in conjunction with a biofilter system could be adequate in reducing dust and odour emissions from Biodegma s MBT plants. D Wastewater: The leachate collected from the process and the waste reception area in the Pößneck facility is partially recycled for wetting the fine fraction before it is composted. The excess leachate is transported off-site to a nearby sewage treatment works, where it is treated with leachate from the nearby landfill. D The company proposes that for future applications of the technology, leachate will be recycled within the process. Consideration will therefore need to be given to the requirements of the UK ABPR when implementing leachate recycling. Agrivert has estimated that about 3.3 litres of leachate per tonne of waste treated would require further treatment, which would be carried out offsite using tankers for shipment of this effluent stream to a suitable treatment plant (c.f. Pößneck). This would significantly increase operating costs but would avoid the capital cost of an on-site water treatment plant. Footprint & Visual Impact D The Biodegma reference plants have a low visual profile. We have already commented on the impact of implementing a thermal off-gas treatment process, which will raise the visual profile of the plant. No information on the land-take of the process was made available for this review. Costs D The treatment cost at Pößneck was reported to Juniper to be in the range 32-37/Tonne (c /Tonne). We were also informed that this does not include the costs of managing the output streams from the plant. The total treatment cost for Neumünster, 1 Biowaste Composting- New developments and solutions for the reduction of odour emissions, HLUG (Hessisches Landesamt für Umwelt und Geologie

44 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-79 BIODEGMA which includes all output management costs, was estimated to be approximately 76/Tonne (c. 46/Tonne). Figure D54: The Pößneck MBT plant Waste reception & pre-processing Biofilter, with structure for composting plant shown in background Source: Juniper (Photograph taken by Juniper during site visit) Outstanding Questions D We have not been supplied with the following information for this review: Plant availability data and the actual throughput for the period of time the Pößneck and Biberach plants have operated; The composition of the RDF currently produced in the process plant at Pößneck; Indicative composition of the SRF that would be produced at Neumünster; The land-take associated with the implementation of the Biodegma process; RDF/SRF specifications required by customers not provided. Summary D Biodegma has been active in biological waste treatment since the early Nineties. The company has extensive experience in building composting plants, for which they have a significant number of reference facilities. The composting system employed by Biodegma is simple in design and construction and could be relatively inexpensive to implement. However, in its present configuration, additional investment may be required to enclose the composting plant for UK implementation in order to minimise the environmental impact.

45 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-80 BIODEGMA D Biodegma are relatively active in the German MBT sector with two plants in operation and two plants currently in the planning/building stage. These latest two process offerings in Germany plan to maximise the production of SRF, which is a significant departure from how the operating plants are configured (bio-stabilised residues to landfill) and represents a major shift in their approach. As this new configuration of the process has not yet been operated on a commercial basis the process cannot be considered fully proven and success of the Neumünster project will be a critical step in demonstrating the flexibility of the Biodegma system. D In the UK, the Biodegma technology is licensed to Agrivert. However, Agrivert s marketing is currently emphasising the Biodegma composting technology for sourceseparated kitchen and food waste, as well as other putrescible fractions. Agrivert is therefore focusing on an output-oriented approach because the company is conscious of the lack of current markets for RDF and SRF in the UK. At this time we do not expect the process adaptations currently being offered to the German market to be promoted for the UK market. This review was prepared in October 2004 from information provided by the company in mid-summer A site visit (Pößneck, Germany) was conducted on 30 August It was finalised in November 2004, following further clarification discussions with the process company.

46 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-81 BTA BTA Summary of the process BTA supplies single and 2-stage wet anaerobic digestion processes for treating MSW and biowastes. These processes have been implemented in MBT configurations in six different countries. For treating MSW, the BTA process combines an extensive wet pre-treatment step with an AD system. On a number of occasions BTA s extent of supply has been the wet pre-treatment system only. The main outputs from the BTA process are biogas, which is used to generate electricity via gas engines, and a digestate which is further bio-stabilised by composting. Type of process being marketed MSW or materials from dry pretreatment Wet pretreatment Wet anaerobic digestion Digestate to further biostabilisation Biogas to electricity Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Commercial plants Advantages Disadvantages Key advantages & disadvantages process demonstrated to treat MSW process is a net energy producer design flexibility that can be tailored to maximise the yield of biogas complex waste pre-treatment process the process will need to manage large quantities of water in a suitable on-site treatment plant lack of data on their key reference plants Contact details BTA Biotechnische Abfallverwertung GmbH & Co KG, Rottmannstr. 18, D München, Germany Tel: Fax: Web: Key contacts Harry Wiljan Managing Director h.wiljan@bta-technologie.de

47 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-82 BTA Overview D Biotechnische Abfallverwertung GmbH & Co. (BTA) promotes a wet anaerobic digestion technology, which has been used to treat various types of waste in MBT configurations. The company was formed in Germany in 1984 to commercialise a process for treating waste developed by REA Gesellchaft für Recycling von Energie und Abfall mbh, which owns the Intellectual Property Rights (IPR) to the technology. BTA, which has the exclusive rights to use and commercialise the process, recently reported a share capital of about 3M. D There are a number of licensees for the process in various parts of the world. The UK based company Purac Limited, which builds plants in the wastewater and sludge treatment sectors, recently signed a license agreement to market the BTA technology in the UK and Eire. Hitachi Zosen Corporation has held the licence to the technology for Japan since October Canada Composting Inc. (CCI) holds an exclusive licence for North America. BTA has also had agreements with a number of organisations in various countries such as Biotec in Italy; which informed us that they are licensed to supply full BTA plants in Italy and to supply the wet pre-treatment part of the process worldwide. BTA also had a license arrangement with MAT (Müll und Abfalltechnik), the German based company that supplied a biowaste reference plant in Ypres, Belgium. We were informed by BTA that MAT ceased trading in early D Juniper visited a reference plant processing vegetable waste supplied by BTA in 2003 near Munich, and was impressed by the standard of process engineering and the positive on-going relationship BTA had with their client. The housekeeping and inbuilding odour suppression were not as good as we would have expected in such a location. However, this plant does not have an integrated mechanical front-end as would be required for treating MSW. D We also visited the Ca' del Bue MBT plant in Verona, Italy in November 2004, which is a BTA reference facility supplied by their Italian licensee (Biotec). The output from the wet pre-treatment stage feeds four anaerobic digesters, which were supplied by others. Although the wet pre-treatment part of the process appeared to be operating well during our visit, we observed that the housekeeping in this area was poor. D The Ca del Bue facility, built by Ansaldo Energy and Snamprogetti, treats 175,000 Tpa of MSW. The MBT plant is surprisingly large (and probably one of the largest MBT plants we have seen during our programme of site visits). It consists of the BTA wet pre-treatment system which produces a slurry from the fine fraction (<80 mm) of the waste input, which is then sent for digestion. The process also makes RDF briquettes from the >80 mm fraction (this part of the process was supplied by Lindner). D The digestion plant produces biogas from the wet slurry, which is being used on-site in gas engines to produce electricity. The RDF briquettes, as well as the dewatered digestate from the anaerobic digesters, are combusted in an on-site power plant, which has an extensive array of fluegas cleaning measures in place.

48 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-83 BTA Figure D55: Photograph of the Ca del Bue MBT plant in Verona Source: Photograph taken by Juniper during site visit D Unfortunately we have been unable to obtain access to the BTA Villacidro MBT plant, which is their most relevant operating MBT facility processing MSW. We have therefore been unable to assess the design, performance and housekeeping associated with a BTA reference plant relevant to this study. Status of Technology D The company operated a pilot plant for about ten years in Garching, near Munich, to develop the process for treating various fractions of MSW. The plant was moved to Baden-Baden in Germany in 1996 and operated for a further two years in developing codigestion of MSW and sewage sludge. Figure D56: Pulpers at the Verona reference site Source: Photograph taken by Juniper during site visit

49 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-84 BTA D The company has reference plants in North America and in Europe (see Figure D57), but in many cases the company s involvement was as a subcontractor to provide engineering expertise and the delivery of plant components; the licensee was responsible for delivering the complete plant. In other cases, BTA has only supplied the waste pre-processing part of their process to feed existing digesters (excluding the AD plant, as described below). Figure D57: BTA s reference plants treating MSW Location Total plant capacity Tpa Input to BTA s supply Tpa Extent of Supply Status Waste treated Start-up Wet pretreatment only Full digestion process via licensee Pulawy, Poland 22,000 MSW, commercial & industrial Villacidro, Italy 45,000 MSW, sewage sludge Toronto, Canada (demo plant) 15,000 MSW, biowaste 2002 Verona, Italy 175,000 70, Alghoba, Libya 11,000 MSW 2005 Krosno, Poland 30,000 MSW 2005 Pamplona, Spain 100,000 MSW The colour coding system denotes plants currently operating ( ) and plants that are under construction, under commissioning or in planning ( ), plant stopped ( ). Source: Juniper analysis of BTA s information The Process Waste Pre-processing D Figure D58 is a schematic of the BTA MBT process for treating MSW. The incoming MSW is separated at a size cut of 150 mm (at Villacidro) using a trommel. Metals and other recyclables are recovered from the screen oversize fraction (>150 mm) by a combination of magnetic separators and hand-picking lines. The remainder of the oversize fraction is sent to landfill.

50 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-85 BTA D Metals are also recovered from the undersize fraction (<150mm) prior to it being sent to a patented batch-operated hydropulper system where the waste is macerated into a fine suspension using recirculated process water to about 8-10% ds 1. The batch process takes about 60 to 75 minutes to complete. The dense materials (metals, glass, heavy inerts, batteries etc) collected in the pulper and the light floating fraction (mainly plastics, textiles and wood) are removed and normally further bio-stabilised off-site before being sent to landfill. The solid suspension is pumped, via a screening system integrated into the bottom of the pulper to remove particles >10mm, to a patented grit removal system, which has at its core two hydrocyclones operated in series. This suspension, which contains mainly biodegradable matter, is pumped from the grit separators to the AD plant. Solids (>10mm) removed in the pulping stage are sent to landfill. Figure D58: The BTA MBT process for MSW MSW Exhaust gases Trommel CHP Unit >150mm Metal Separator <150mm Metal Separator Femetals Gas Cleaning Heat & Power Ferrous metals Biogas Solids to composting Manual Sorting Hydro Pulper Grit removal AD Plant Dewatering Potential recyclables Light fraction Process water Residues to landfill Heavy fraction Wastewater Wastewater Treatment KEY Recyclables Further upgrading Effluent Stream Residue Stream Energy Source: Juniper analysis of BTA s information D The company offers the AD process for both single-stage and two-stage operation, which can operate under mesophilic or thermophilic conditions. However, the only 1 ds = dry solids

51 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-86 BTA operating plant treating MSW in which the company has supplied their full process, Villacidro, Italy, is configured as a two-stage process to treat MSW and sewage sludge (see Figure D57). The description that follows is for that process. BTA informed us that it is not a requirement to co-process sewage sludge to treat MSW with their anaerobic digestion system. D The main process data associated with the various BTA process designs are summarised in Figure D59. Figure D59: Generic process information for the BTA AD configurations Operating parameter BTA single-stage process Anaerobic Digestion BTA two-stage process 1 step digestion Hydrolysis Methanisation Retention time, days Temperature, 0 C Mesophilic Thermophilic Biogas production (from biowaste), m 3 /Tonne c c CH 4, (vol %) CV (MJ/m 3 ) Energy output, (MWh/ton) c Source: Canada Composting Inc. ( AD Plant D In the AD plant the suspension from the wet pre-treatment stage is first treated in a hydrolysis reactor. The outlet stream from the hydrolysis stage is sent to a centrifuge, which separates the suspension into two fractions. The fine suspension is pumped to the methanisation reactor, while the solids are sent to a solids dewatering plant. A portion of the solids is recycled back to the hydrolysis stage. The dewatered solids are then sent for composting to enhance the bio-stabilisation of the output. It is not clear whether the bio-stabilised output from the post-digestion composting process at Villacidro is being utilised or landfilled. D The water recovered in the dewatering stage is recirculated as process water. Excess water is removed from the process and sent to a water treatment plant. D In the methanisation reactor, the suspension is stirred by recirculating compressed biogas fed through lances fixed in the digester. The suspension is also continuously recirculated by pumping through external heat exchangers to maintain the operating temperature of about 37 0 C. The agitation of the suspension minimises the formation of sedimentation and floating layers in the digester. The HRT in the 2-stage digestion

52 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-87 BTA plant is about eight days and the biogas yield ranges from about Nm 3 /Tonne depending on the waste composition. The biogas produced is utilised in gas engines to generate electricity. Process Performance D The data in Figure D60 is based on information from the Villacidro plant. However, as the information is incomplete, we were unable to determine the landfill diversion performance of the MBT processes. Energy Balance D No data was provided to determine the energy output from the system, although some generic process information is summarised in Figure D59. D It is reported that the Ypres biowaste plant exports about 50% of the electricity produced. This may be less for a similar sized MBT plant because of the additional mechanical processing of the input waste that would be required. Figure D60: Inputs & Outputs for BTA s wet digestion process as operated in Villacidro MSW (74%) Sewage sludge (26%) Biogas (NR) Feedstock preparation Wet Anaerobic Digester Rejects to landfill (14.1%) Fe & non- Fe-metals (1.3%) Dry recyclables (paper, cardboard, wood, textiles) (16.7%) Liquid effluent (NR) Digestate (13.5%) Composting Bio-stabilised output (NR) Waste Gases (NR) Rejects (NR) NR = not reported Source: Juniper analysis of BTA data

53 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-88 BTA Process Flexibility Input materials D The BTA process is being used to treat various organic waste (including food waste, manure and organic sludges) in at least seven plants, which range in capacity from about 5,000 Tpa to 150,000 Tpa). Figure D61 lists BTA s biowaste reference plants. At least 13 other plants cited by the company as references incorporate the wet pretreatment part of their process or other components only. Figure D61: BTA's references treating organic wastes or a segregated organic fraction of MSW Extent of Supply Location Capacity Tpa Wet pretreatment only Components Full process Status Startup Elsinore, Denmark 20, Kaufbeuren, Germany 2, Baden-Baden, Germany 5, Karlsruhe, Germany 8, Schwabach, Germany 12, Erkheim, Germany 11, Munich, Germany 20, Dietrichsdorf, Germany 17, Münster, Germany 20, Wels, Austria 15, Wadern-Lockweiler, Germany 20, Newmarket, Canada 150, Karlshof, Germany 8, Mertingen, Germany 12, Kushima City, Japan 1, Mülheim, Germany 22, Ko-Sung, South Korea 3, Parramatta, Australia 35, Nara City, Japan 1, Ieper (Ypres), Belgium 50, The colour coding system denotes plants currently operating ( ); plants that are under construction, under commissioning or in planning ( ). Source: Juniper analysis of BTA s information

54 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-89 BTA Operability and Availability D No data was provided for this review. Environmental Impact D The process produces an excess of water even after the recirculation of water to meet process needs. No data about the quantity and quality of wastewater produced at the Villacidro plant was provided for this review. At Villacidro the excess wastewater is treated in an existing water treatment plant, which indicates that integrated wastewater treatment might have to be implemented for some projects using the BTA process. D No data on the levels of gaseous emissions from the engines used at Villacidro was made available for this review. D The pre-processing plant supplied by BTA at the Ca del Bue facility which we visited, is housed in a partially enclosed building. It appeared as though fugitive emissions from this part of the process were not controlled. As we could not visit Villacidro we are unable to comment on the issue of process odours, particularly when co-processing sewage sludge. Footprint & Visual Impact D The 45,000 Tpa process at Villacidro has an estimated land-take of 2,800m 2, which translates to c m 2 /Tpa. The anaerobic digesters at the Ypres plant in Belgium are 15m high and are likely to be the tallest process item in the BTA MBT process. It is unclear whether similar size digesters are provided for plants treating a mixed MSW feedstock. Figure D62: BTA s digesters in Ypres, Belgium Source: BTA

55 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-90 BTA Costs D The company only provided information for the items they have supplied to MBT plants. The cost for the wet pre-treatment process ranges from 2.5M (c. 1.5M) to 4.0M (c. 2.5M). Capital cost data for the complete Villacidro plant was not provided. D The 50,000 Tpa biowaste plant at Ypres in Belgium is reported to have cost 20M (c. 12.5M). We understand that this capital cost includes: land cost; infrastructure; and the cost of utility buildings. No operating cost data was provided. Outstanding Questions D A number of questions remain pertaining to the quantity and composition of the various output streams from a relevant reference plant. We could not therefore determine the landfill diversion performance of the BTA process or the potential environmental impact of the output streams. No information concerning the degree of biodegradation achieved within the process was provided. D No data on the yield or composition of biogas produced when treating MSW was provided and no energy balance data was supplied to determine the net energy output from the MBT process treating MSW although we expect that the BTA process would be a net producer of energy and power. D The levels of potential contaminants in the wastewater, gaseous emissions and the biostabilised fraction from the composting stage when treating MSW are extremely important. However, no data was made available for this review. D No data on the level of bio-stabilisation of the digestate in the composting stage was made available for this review. D Although data on land-take was provided, we could not fully estimate the visual impact of the facility based on the height of the process elements. D No cost information was made available for the full BTA process for treating mixed MSW. Summary D Formed in 1984, BTA is a leading supplier of wet AD technologies. The company has a significant number of biowaste reference plants and has supplied parts of their technology for large scale MBT plants. However, there is only one relevant MBT reference plant treating MSW, where the whole integrated process is being operated in accordance with the BTA design.

56 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-91 BTA D There are a number of licensees for the technology for different parts of the world. Currently this means that the BTA process is being used in at least six countries at various scales. MAT s bankruptcy in early 2004 affected a number of waste projects in which the company was involved (such as Ypres, Belgium, which has been significantly delayed). However, a number of new projects are planned for 2005, which indicates that the company is still actively securing contracts for the technology. This review was prepared in October 2004 from information provided by the company in the same month. We conducted a site visit (5 November 2004) to the company s Verona reference facility where only the BTA pre-treatment system has been supplied and had previously visited their reference facility in Munich (2003). We could not gain access to BTA s most relevant MBT reference plant in Villacidro, Italy. The review was finalised in February 2005, following further clarification discussions with the process company.

57 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-92 CIVIC CIVIC Summary of the process Civic has developed an MBT plant that utilises in-vessel composting. The process has been operated on unsegregated MSW at a demonstration facility since Plans are in progress to double the size of the current plant for full commercial operation in Main output from the process is a bio-treated material that is being used as landfill cover and as a soil improver. Type of process being marketed MSW In-vessel Composting Posttreatment Fe & non-fe metals & other dry recyclables Soil imp rover Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Operating Commercial plant At the time of writing current plant was being expanded Advantages Disadvantages Key advantages & disadvantages process demonstrated on unsorted MSW operational experience in the UK demonstrated at relevant scale lack of data on the degree of biostabilisation of the organic material process will be a net energy user Contact details CIVIC Environmental Systems Ltd, New Street, Holbrook Industrial Estate, Sheffield S20 3GH, United Kingdom. Tel: Fax: Key contact Peter Lowe Managing Director peterlowe@hadee.co.uk

58 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-93 CIVIC Overview D Civic Environmental Systems (CES), established in 2002 in the UK, markets the patented civic (c ontrolled i n-vessel i ndigenous c omposting) process - a semicontinuous system operated at C. This process is being operated currently with black bag waste at a demonstration plant at the Thornley Waste Transfer Station in County Durham, UK. D CES is a sister company to Hadee Engineering (the company that built the demonstration plant), which is an established UK design and equipment fabrication company with a long history in manufacturing equipment for the coal, mining, steel and aerospace industries. The two companies form the Yorkshire based Hadee Holdings group, which reported a turnover of about 6M ( 9M) in D The composting process being promoted by CES has been developed over a number of years with the involvement of various organisations, including Yorkshire Water. In recent years the process has been further developed by CES with project implementation assistance from the University of Newcastle, Premier Waste Management and County Durham Environmental Trust. We understand that Civic owns all rights to the process. CES now offers the process on a Design, Build and Transfer basis, with the present system in County Durham being operated by Premier Waste Management. D The rated capacity of the process when it started operation in 2002 was 8,000 Tpa but the process has now been optimised in the same reaction vessel to a capacity of 15,000 Tpa by decreasing the composting time and increasing the amount of waste treated in each batch. CES informed Juniper that trials have indicated the process can be further optimised to a capacity of about 22,000 Tpa by further increasing the quantity of waste treated in each batch. Status of Technology D When Juniper visited the demonstration plant in March 2004, it was still operating. The plant was well engineered and the plant layout uncomplicated, which may be due to its relatively small capacity. We also observed that initial construction work to double the capacity of the plant was in progress and we were informed that the larger capacity plant should be operational in January 2005 on a commercial basis. The company informed us that the UK Environment Agency had indicated that an IPPC permit would not be required to operate the plant and that the new plant could be operated with an amended waste management licence. In recent communications with Civic they indicated that construction work has been completed and the system is in the process of being brought online.

59 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-94 CIVIC Figure D63: The Civic plant at Thornley waste transfer station for 8,000 Tpa mixed MSW Source: CES The Process D Figure D64 is a schematic of the Civic process that has been operated at Thornley. Waste feeding & composting D The waste input to the process has been black bag waste delivered to the Thornley transfer station. The crane operator removes bulky items from the waste before loading it into a rotary shredder. The shredder reduces the size of the waste to about 60mm, which is then conveyed on uncovered belts to the top compartment of the composting tower (see Figure D65). The tower has three independently controlled compartments, isolated from each other by hydraulically activated in-floor doors. Each compartment has an off-gas removal port. The extracted gases are piped to a scrubber, which partially cleans the gases and removes some of its water content by condensation. The gases leaving the scrubber pass through a containerised bio-filter before being vented to atmosphere. D The moisture content of the input waste to the tower is monitored and, when necessary, recycled process water is added to humidify the waste. Each compartment is periodically stirred by mechanical rotating arms and air is introduced as required (based