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 K-R: Komptech Linde Nehlsen New Earth OWS Ros Roca Rumen 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-212 KOMPTECH KOMPTECH Summary of the process Komptech manufactures various mechanical systems that have been used in MBT plants (supplied by others) for pre-treating MSW and refining biostabilised materials. The company has constructed one MBT plant. They do not have their own biological waste treatment technology and utilise third-party biological systems for project implementation Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Commercial plant General contractors for one MBT plant for which they supplied the mechanical processing equipment Key advantages & disadvantages Advantages recognised as a leading supplier of materials handling, sorting and recycling systems for a range of waste applications this knowledge and expertise is valuable because poorly conceived and engineered mechanical elements can be the source of poor operational performance in MBT plants Disadvantages have not yet supplied a complete integrated MBT process Contact details Komptech UK LTD. Forge End, Lodge Farm, Kineton, Warwick CV35 0JH Tel: Fax: Web: Key contact Paul Carley Director p.carley@komptech.com

4 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-213 KOMPTECH Overview D Komptech-Farwick GmbH (renamed Komptech GmbH from the 1 st January 2005) is principally a manufacturer and supplier of mechanical processing equipment. Their supply typically includes crushing, mixing, screening and compost turning machinery, which they have supplied to a number of MBT plants supplied by others. D The company was formed in 1999 when Heissenberger & Pretzler GmbH (which marketed various types of machinery for waste treatment under the trade name Komptech ), acquired a majority shareholding in Maschinenbau Farwick GmbH, a privately owned company that manufactures various mechanical separation and compacting equipment. In 2002, Komptech-Farwick acquired BG-Recyclingmaschinen GmbH, which manufactures star screens 1 that can remove contaminants from high moisture content materials such as compost. D Komptech (comprising of the five subsidiaries listed below) reported a turnover of 50M in Maschinenbau Farwick (now Komptech Umwelttechnik Deutschland GmbH), responsible for project development in Germany; Komptech Umwelttechnik, responsible for shredding and composting technologies; Komptech Farwick Anlagenbau (now Komptech Anlagenbau), based in Austria and formed in 2003, is responsible for project development in Austria and the EU Accession Member States; BG-Recyclingmaschinen GmbH (now Komptech Vertriebsgesellschaft Deutschland mbh (which manufactures star screens); UK based Komptech Ltd, responsible for marketing operations in the UK. D Komptech Anlagenbau has supplied mechanical systems to a number of MBT plants in Germany and Austria, listed in Figure D154, and is regarded by several of the companies we interviewed as a market leader in this area. D The company, along with the Dutch subsidiary of Horstmann, WTT (Waste Treatment Technologies BV), were the general contractors that constructed the recently commissioned Frohnleiten MBT facility in Austria. For this facility Komptech-Farwick supplied the mechanical pre-treatment process and the refining process for the biostabilised residues. D As the company currently does not have their own biological process technology, their preferred implementation strategy is to integrate their own mechanical processing equipment with biological systems supplied by third parties, depending on the requirements of the project. Their strategy is therefore two-fold (and similar to a 1 Star screen a relatively efficient, high throughput screening system. Changes to the size of particles screened can be made by adjusting the speed at which the machine operates.

5 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-214 KOMPTECH number of other European engineering companies); to develop a role as turnkey contractors for full MBT projects, and to be suppliers for their own mechanical processing equipment to other MBT projects. Figure D154: Komptech s supply to some MBT facilities treating residual MSW Location Plant Capacity Tpa Status Shredders Mechanical Equipment Supplied Waste splitting Pretreatment Posttreatment Biological process supplier Linz, Austria 60,000 Linde Minden, Germany Erbenschwang, Germany Lübeck, Germany 100,000 Horstmann 40,000 Sutco 150,000 Haase Frohnleiten, Austria 65,000 WTT/ Horstmann Oldenburg, Germany Lauchhammer, Germany 80,000 Horstmann 50,000 Haase The colour coding system in denotes equipment currently operating ( ) and not equipment not yet in operation ( ). Source: Juniper analysis of information supplied by Komptech-Farwick and from the company s website ( D In our experience, this type of project implementation could involve significant process integration risks. While we understand that Komptech s only MBT reference facility in Frohnleiten, Austria is now fully operational on a commercial basis, they did not supply the complete integrated process. We could not obtain detailed information and data to assess the performance of this MBT plant and therefore cannot comment as to whether this process has operated successfully. This review was prepared in December 2004 from information provided by the company in August 2004 and information obtained from the company s website and other public domain sources. Despite requests for further information to determine the performance of the company s only MBT reference facility no additional information was provided for this review. The company explained that detailed process data from this reference plant is currently being compiled but was not yet available. The review was finalised in January 2005 after further clarification with Komptech.

6 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-215 LINDE LINDE Summary of the process Linde markets a number of different processes, which utilise dry AD, wet AD, tunnel or aerated pile composting as the core biological step. Individual concepts can be optimised to produce electricity from biogas, RDF or biostabilised outputs. A few examples of configurations Linde has implemented are summarised below. Type of process being marketed (1) MSW Pre- Sorting 2 Stage Wet AD Tunnel composting (2) MSW Metal RDF Pre- Sorting Biogas to electricity Dry AD Soil improver Tunnel composting (3) \MSW Metal Pre- Sorting Biogas to electricity Tunnel Composting Compost Aerated pile maturation Metal Bio-stabilised output for landfilling (1) as operated at Ecoparc1, Barcelona. (2) as operated at Valladolid Spain. (3) as operated in Linz, Austria Commercial status No plant yet built Pilot Plant Demonstrator plant Commercial plants Advantages Disadvantages Key advantages & disadvantages several process configurations proven on mixed & segregated MSW Linde has the broadest set of reference sites on a wide range of input wastes and is capable of supplying bespoke systems eleven reference plants operating on a commercial basis in four different EU Member States experience in all aspects of MBT did not provide data on performance from any of their reference plants Contact details Linde-KCA-Dresden Gmbh, Lunzerstraβe 64, 4030 Linz, Austria. Tel: Fax: Key contact Martin Hagenmeyer Sales Manager: Waste Treatment Plants martin.hagenmeyer@linde-kca.com

7 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-216 LINDE Overview D Linde-KCA-Dresden GmbH, founded in 1990, is a wholly owned subsidiary of the German international technology group Linde AG, which has been operating since 1879 as a world-class supplier in the refrigeration and industrial gases sectors. The group has diversified over the decades and in 2002 reported a turnover of more than 8 billion from machinery and equipment sales in three core business areas: Gas & Engineering; Materials Handling and Refrigeration. D Linde-KCA-Dresden reported a turnover of 126M in 2003 and falls under the gas and engineering division, which designs and builds chemical, gas, pharmaceutical and environmental plants. The company evolved from the Mechanical Biological Waste Systems division of Austrian Energy, which had a long history in engineering biological treatment plants for wastewater and sewage sludge applications. This division of Austrian Energy was acquired by Linde AG in 1998 and the company also acquired BRV Biowaste Technologies AG a Swiss based company that specialised in dry anaerobic digestion of waste at around the same time. D Unlike many of the MBT suppliers reviewed in this Report, Linde supplies both turnkey plants (including the mechanical separation equipment) and specific process equipment. Figure D155 gives an indication of the extent of the company s supply at their various MBT reference plants. Status of Technology Process Configuration D Linde offers their MBT concept in two variants: one that concentrates on bio-stabilising the entire waste stream, followed by mechanical separation of the bio-stabilised materials to recover recyclables, a solid fuel and residues for landfilling; and a second process concept that aims to biologically treat a derived fraction of material from the MSW stream. D The first process variant offered by Linde has not been supplied on a commercial basis to date. D To achieve these two different process variants, the company utilises anaerobic digestion (dry or wet) or composting (tunnel or aerated pile) as the core biological process step. D Many of the MBT plants supplied by Linde between the early 1980 s and mid 1990 s utilised mechanical separation with aerated pile composting as the main biological

8 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-217 LINDE processing step. Since then they have mainly utilised wet digestion or in-vessel tunnel composting as the core biological processing step at their reference facilities. D Figure D155 lists Linde s extensive reference facilities. At the time of writing this review, 12 plants utilising Linde s technology for treating MSW are reported to be operating in five different countries: five of these plants utilise aerated pile composting as the core biological step; three utilise tunnel composting; three utilise wet AD; and, one utilises dry AD. Figure D155: Linde s reference facilities treating MSW Location Plant Capacity, Tpa Current Status Pre-treatment equipment Scope of Supply Equipment supplied for non-turnkey plants Turnkey Plant Pile or Tunnel Composting Dry or Wet AD Comments Startup Pile or Tunnel Composting Dry or Wet AD Zell am See, Austria 30, Capella Cerezara, Italy 25,000 su 1978 Prague, Czech Republic 70,000 su 1979 Mantua, Italy 25,000 su 1979 Allerheiligen, Austria 18, Stromstad, Sweden 22,500 su 1980 Liezen, Austria 12,500 Pontives (Groden), Italy 32,000 stopped in 2003 for modernisation only mechanical pre-treatment plant operating

9 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-218 LINDE Location Plant Capacity, Tpa Current Status Pre-treatment equipment Scope of Supply Equipment supplied for non-turnkey plants Turnkey Plant Pile or Tunnel Composting Dry or Wet AD Pile or Tunnel Composting Comments Startup Dry or Wet AD Aspach le Haut, France 50,000 su 1985 Graz, Austria 100, Dubai, U.A.E 30, Al Ain, U.A.E. 270, Salzburg- Bergheim, Austria 150, Oberpullendorf, Austria 36,000 plant being modernised 1988 Venedig, Italy 62, Bangkok, Thailand 300,000 stopped in Lomnice, Czech Republic 30,000 stopped due to lack of financing 1993 Setubal, Portugal 46, Eurasburg/Quarzbi chl, Germany NR dry digestion pilot plant 1996 Ravensburg, Germany 1,500 dry digestion pilot plant Borken, Germany 85, Barcelona, Spain (Eco Parc 1) 300,

10 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-219 LINDE Location Plant Capacity, Tpa Current Status Pre-treatment equipment Scope of Supply Equipment supplied for non-turnkey plants Turnkey Plant Pile or Tunnel Composting Comments Startup Dry or Wet AD Pile or Tunnel Composting Dry or Wet AD Valladolid, Spain 200, Madrid, Spain 140, Villena, Spain 75, Linz, Austria 60, Burgos, Spain 80,000 startup in June Chemnitz, Germany 100,000 not yet built 2005 Salto del Negro, Spain 200,000 planned for Feb Lorient, France 65,000 not yet built 2005 Leipzig, Germany 300,000 + not yet built 2005 Fridhaff, Luxembourg 45,000 not yet built 2005 Schoneiche (near Berlin), Germany 180,000 + not yet built 2005 Erfurt, Germany 90,000 not yet built 2005 Lille, France 200,000 not yet built 2006 su status uncertain NR Not Reported The colour coding system denotes plants currently operating ( ), plants that have ceased operating ( ) and plants that are under construction or in planning ( ). The ticks in the Equipment supplied and Turnkey plant columns of this figure are also colour coded to identify which technologies (in brown and blue) have been applied at each reference plant. Source: Juniper representation of Linde s information

11 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-220 LINDE Description of Technologies D Because the company markets and supplies a number of different types of MBT process, they do not promote a typical MBT process. We have therefore provided below a brief description of each of their core biological process offerings, which have been incorporated into various MBT process designs. Wet Anaerobic Digestion D Linde s wet digestion process is designed to treat mainly pre-treated wastes. This process has been implemented to treat the sieve fraction of mixed MSW at the company s Spanish reference facilities and also to treat various biowastes (see Figure D156). Figure D156: Linde s wet digestion process as operated at Ecoparc 1 Barcelona Waste Hand-picking Trommel Recyclables Rejects Exhaust gases Gas Engines >100mm <100mm Metal Separator Metal Separator Fe & non- Fe metals Gas Cleaning Power Fe & non-fe metals RDF Biogas Solids to composting Water Waste Pulper Hydrolysis Wet Digester Press Water Light Substances Heavy Substances Wastewater Wastewater Treatment KEY Recyclables Further upgrading Effluent Stream Residue Stream Energy Source: Juniper representation of Linde s information

12 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-221 LINDE D When implemented to treat MSW, the wet digestion process is operated predominantly in a two-step configuration (hydrolysis and methanogenesis) under mesophilic conditions ( C). We discuss the advantages and disadvantages associated with one and two-step AD in Annexe A. D After removing the coarse fraction of the waste stream via trommels and recovering metals, the fine fraction of the MSW is essentially pulped to give a TS 1 of about 10% before being hydrolysed and then digested in separate reactors. At the pulping stage much of the heavy inerts and sand are removed. However, sand is carried forward into the hydrolysis tank and this has to be removed periodically. D A portion of the biogas produced in the digesters is recirculated through pipes installed in the digester to aid mixing. Hot water produced from cooling the gas engines is used to heat the contents of the digester, which is continuously recirculated through external heat exchangers. The remainder of the biogas is cleaned to minimise its H 2 S (hydrogen sulphide) and particulate content and to remove water before it is sent to the gas engines to produce electricity. D The solids removed from the digester (the digestate) are dewatered and sent to a composting plant for bio-stabilisation. A portion of the water from the dewatering press is recirculated into the waste pre-treatment stage and the remainder sent for treatment. D Linde s wet digestion process is therefore aimed at treating only part of the incoming waste to produce biogas and a bio-stabilised residue. Figure D157 lists the MSW reference plants currently using wet AD. All of the plants are being operated in mesophilic mode using the two-step approach. Figure D157: Linde references with wet anaerobic digestion systems for treating MSW Location Capacity of Digestion plant, Tpa Waste Input to plant Barcelona, Spain 150,000 Partially segregated household waste Madrid, Spain 73,000 Unsegregated household waste Burgos, Spain 40,000 Unsegregated household waste Salto del Negro 75,000 Unsegregated household waste Source: Juniper representation of Linde s information D We visited one of Linde s MBT references in Eco Parc 1, Barcelona, which utilises wet digestion. The facility, which has been operating for nearly three years, was well engineered and fully enclosed and consists of a mechanical pre-treatment plant, which processes 300,000 Tpa of input, four Linde digesters treating a total of 150,000 Tpa and 38 composting tunnels (also supplied by Linde) treating digestate and source segregated organic waste. 1 TS = total solids ( % of solids contained in the stream)

13 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-222 LINDE D Prior to our site visit, we had been informed by others that the Barcelona plant had experienced difficulties with the digesters. During our site visit we were pleased that Linde themselves chose to raise this topic about problems with floating layers 1, which affected performance of the digesters. Linde explained that the actual waste input differed significantly from the specifications they had been provided with, which they used to design the digesters. We saw a few of the modifications that had been implemented to prevent the build up of these floating layers. Figure D158: Linde s Eco Parc 1 reference plant The fully enclosed mechanical pre-processing plant Inside the mechanical preprocessing plant Source: Photographs taken by Juniper during site visit D We were expecting to receive biogas production data, which would have shown whether the process is now operating reliably, but this was not provided. In the absence of this data, potential clients would have to satisfy themselves that this issue has indeed been addressed. D Overall the house keeping at this plant was of a reasonable standard and we did not detect any significant odorous emissions outside the plant, which is relatively close to an urban conurbation. 1 Light materials that include corks, plastic tubes and polystyrene that float to the top of the digester. This is a problem that has been experienced in a number of wet digestion plants.

14 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-223 LINDE Dry Digestion Figure D159: Linde s dry digestion process Exhaust gases Waste Mechanical Pretreatment <100 mm Metals Rejects Gas Cleaning Gas Engines Power Biodegradables Biogas Residue to maturation Pre-composting (Hydrolysis) Crushing Dry Digester Dewatering press Press water Rejects Wastewater Wastewater Treatment KEY Recyclables Further upgrading Effluent Stream Residue Stream Energy Source: Juniper representation of Linde s information D The company s only operating dry digestion plant treating MSW is located in Valladolid, Spain. The total waste input to this plant is 210,000 Tpa with 83,000 Tpa processed in Horstmann composting tunnels, after mechanical and manual separation stages, and 15,000 Tpa treated in Linde s dry digestion process. D The digester is operated in thermophilic mode ( C) and utilises horizontal plug flow reactors in which the SRT 1 is approximately 25 days. It is fed from a pre-treatment stage where the waste is hydrolysed for about two days with recycled water recovered from the digestate. After digestion the mechanically dewatered digestate is sent for maturation. A portion of the biogas produced is burnt and the heat generated used to heat the contents of the digester. D We visited the Valladolid plant in September The Linde digestion reactor was not the usual cylindrical design, but a horizontal rectangular shaped reactor, which was housed in a fully enclosed building (see Figure D160). The digestion process appeared to be fully operational but we detected significant odorous emissions, which seemed to be associated with the co-digestion of sludge and the feeding of this material to the digestion plant in open conveyors. The way the plant is being operated is of a poor 1 SRT = solids residence time

15 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-224 LINDE standard and while it is unlikely that Linde is still actively involved with this plant, it could be perceived as a poorly operating Linde MBT reference site. Figure D160: Valladolid reference facility Building housing digester Biogas buffer tank Source: Photograph taken by Juniper during site visit D Linde informed us that their preference is to install the dry digestion system where the size of the plant is an issue and where the waste feedstock is better defined. This is mainly because of the inherently smaller size of dry digestion plants (less water to transport and treat and usually fewer pre-treatment stages). Tunnel Composting D Linde s tunnel composting process has been implemented on its own or in combination with the wet AD process (see Figure D155) at five reference plants. When implemented as a standalone system the tunnel composting process has been used to treat the sieve fraction of the MSW to obtain a bio-stabilised output that is suitable for landfilling. When configured in combination with wet AD, the process is used to further bio-stabilise the AD digestate. D The composting process usually takes four weeks to complete, with a further two weeks being required for maturation before the material is fully bio-stabilised. The RDF output from the Linz plant is compacted and sent to a local incinerator. No further information was made available about the quality of the RDF output stream and where in Austria it was being utilised. D We visited the Linz plant in April The plant had recently started operating and was still in its commissioning phase, with some building works being carried out. No data was available at the time about the performance of the process at this facility.

16 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-225 LINDE Figure D161: Linde's composting tunnels at Linz, Austria Source: Photograph taken by Juniper during site visit Figure D162: Linde s tunnel composting process as operated at Linz, Austria Shredder Waste Trommel >80mm <80mm Metal Separator Fe & non- Fe metals RDF Metal Separator Fe & non- Fe metals Organic materials Waste gases to biofilter Air Bio-stabilised solids for landfill Rejects Structure materials Mixing Tunnel Composting Maturation Fresh water Leachate Wastewater Wastewater Treatment KEY Recyclables Further upgrading Effluent Stream Residue Stream Source: Juniper representation of Linde s information

17 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-226 LINDE Figure D163: MSW Reference plants with tunnel composting Location All waste to tunnel composting AD residues to tunnel composting Startup Borken, Germany 2000 Barcelona, Spain 2001 Madrid, Spain 2003 Villena, Spain 2004 Linz, Austria 2004 Source: Juniper s representation of Linde s information Aerated Pile Composting (Windrow Composting) D Linde s early MBT facilities utilised this technology to treat mechanically separated MSW. The technology has not been implemented as the core biological treatment step at any new facility since D The process is offered in two configurations: one in which the material being composted is turned once per week and treated for a period of 8-12 weeks; and the other, which incorporates various process controls for aeration, turning intervals and re-watering. In the latter system the material is turned at shorter intervals and composted for a period of 3-5 weeks. Figure D164: Schematic of Linde s aerated pile process Waste Mechanical Pretreatment Recyclables Rejects Waste gases to biofilter Aerated Pile Composting Bio-stabilised output Air KEY Recyclables Further upgrading Effluent stream Residue Stream Source: Juniper s interpretation of Linde s information

18 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-227 LINDE Process Performance D Linde has supplied turnkey MBT processes or components of their various biological technologies and mechanical pre-treatment systems to a relatively large number of MBT facilities. Based on their large number of reference facilities, Linde can be considered to be one of the leading suppliers of MBT systems. They offer a wider range of MBT solutions using different core biological technology. D The company has clearly built up a significant amount of experience in MBT with a number of reference plants dating back to the mid 1970 s and located in at least seven different countries. Their technologies have been implemented in various capacities for treating 12,000 Tpa to 150,000 Tpa and one plant (Barcelona), which receives 300,000 Tpa MSW input. D As the company s preferred implementation strategy is to Build and Transfer they are no longer associated with a number of their reference facilities, as is apparent from Figure D155. While they have proven experience with supplying commercial MBT plants, we have not been provided with any mass or energy balance data for this review to assess the benefits of using one Linde approach versus another. Process Flexibility Input materials & process scale D Linde s technologies have operated commercially on a number of different organic waste streams, including: Biowaste (separately collected organic waste); Agricultural waste (manure); Residual MSW ( grey-bag waste); Sieve fraction of MSW; Mixed wastes. D Figure D165 summarises Linde s experience and indicates the flexibility of Linde s biological technologies for treating various types of waste. No other company can demonstrate this breadth of reference projects. Environmental Impact D Gas cleaning: Linde implement three different biogas cleaning techniques to reduce hydrogen sulphide (H 2 S) at their MBT reference plants. The level of this contaminant in the biogas for use in gas engines is usually stipulated by the engine manufacturer. The

19 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-228 LINDE more standard approach using ferric chloride (FeCl 3 ) to abate H 2 S, is used at the wet digestion plants treating MSW. The second approach is the company s own patented system in which air is injected at a controlled rate to the gas space in the digester to reduce the action of H 2 S forming bacteria. We were informed that this process is being used at all of Linde s wet digestion plants in Spain in combination with the standard approaching using ferric chloride. The third gas cleaning method being used by Linde is a biological gas cleaning system, which is being used at the dry digestion reference plant in Valladolid. Figure D165: Commercial plants in which Linde s technologies have operated Waste treated Technology supplied Capacity 1 (ktpa) Number of references Windrow Tunnel composting Intensive composting Wet AD Dry AD Biowaste Manure * Agricultural residues * Garden waste * MSW as MBT** Industrial (household type waste) * - 85* Sewage sludge * Organic food waste * Total The capacities indicated are the actual quantity of organic waste sent to the digestion process. * Total capacity for multiple wastes feed ** some plants may be no longer operating (see Figure D155) Source: Juniper analysis of Linde s information D Typically in Linde s MBT processes, the water and particulate content of the biogas are also reduced before it is utilised in gas engines.

20 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-229 LINDE Footprint & Visual Impact D Figure D166 is a summary of the process elements at some of Linde s reference plants. Figure D166: Footprint & visual impact data for some of Linde s MSW reference plants Reference plants Waste sent for digestion Tpa No. of Digesters Height of digesters, m Digester volume, m3 No. of composting tunnels Barcelona 90, , Madrid 73, , Borken 63,000 0 NA NA 26 Linz 40,000 0 NA NA 16 Valladolid 15, ,500 NA NA = not applicable Source: Juniper representation of Linde s data D From the table it is apparent that the company can tailor the design of the digester to suit specific project requirements and should be able to design plants with a relatively low height if this is required. Figure D167: Linde digester and biogas flare at Eco Parc 1 in Barcelona Source: Photograph taken by Juniper during site visit

21 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-230 LINDE Costs D Cost data for some of Linde s most recent MSW references is summarised in Figure D168. Figure D168: Costs associated with some of Linde s MSW reference plants Costs Barcelona, M Madrid, M Linz, M Borken, M Capex c. 48 c. 36 c. 19 c M = million Euro Source: Linde Outstanding Questions D No mass and energy balance data was provided for any of Linde s reference plants. We were therefore unable to determine the landfill diversion performance of any of Linde s MBT process configurations or their relative benefits in terms of BMW performance. D We were not provided with data on the product quality from any of Linde s reference plants. This data is desirable to potential users of this technology to give some indication of the possible outlets that are practicable for the various outputs such as bio-stabilised solids and RDF. D No availability data was provided for any of the reference plants. Because a number of projects using Linde s MBT supply have ceased operating and there would have seem to have been some operational problems at others, further evidence will be required as to the reliability of particular implementations of the technology for certain projects. D No data on the land-take at the various reference plants was provided for this review. Summary D Linde is a major supplier of MBT processes with a long-standing track-record in this field. Their experience with MBT dates back to the mid-1970 s and since then the company has achieved more than 25 MBT references in nine different countries and has a further eight facilities in their new-projects portfolio. D The company has managed and implemented full turnkey projects, providing the full extent of supply and they have extensive technical and engineering resources in Austria to design and manufacture all of the relevant MBT process equipment. D Linde offers an unparalleled number of different types of MBT designs that have been tailored to complement the requirements of waste management strategies and product markets in different countries, many of which they have already implemented at more

22 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-231 LINDE than one plant. Because the company can supply systems utilising any of their core biological technologies, singly or in specific combinations, it is likely that they can respond to the differing requirements of many competitive waste management tenders. D It is unfortunate that Linde did not provide more comprehensive data on the performance and operating parameters of their reference plants. Even though the company is undoubtedly a leading supplier, more evidence of sustained, trouble-free operation at those reference plants would have been desirable. D Linde has substantial corporate resources and despite the absence of data, they can be regarded as a credible supplier who would likely be shortlisted in competitive MBT tender exercises. D Linde has worked in cooperation with major waste management companies, Local Authorities and a number of other MBT process developers, in various EU Member States. D The company, like many other Continental suppliers of MBT, have not operated an MBT plant in the UK and would need to modify some of the process designs in order for them to comply with the UK ABPR. This may increase the cost and implementation time compared with projects presently offered elsewhere. This review was prepared in November 2004 from information provided during site visits to Linz and Wels, Austria in April 2004; and to Barcelona in July We also visited the Valladolid reference in September 2004 where we also saw the Horstmann composting tunnels at this facility. Data on a number of performance indicators was sought in discussions with Linde during the site visits in April and July 2004, but we did not receive further information from the company. The review was finalised in January 2005 after further discussions with Linde.

23 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-232 NEHLSEN NEHLSEN Summary of the process Nehlsen is marketing an MBT process which utilises aerobic drying. The process drives off moisture from the waste by utilising its biological activity. The dried waste is passed through a number of screening stages to produce an SRF, which is currently being used as a co-fuel in cement kilns in Germany. Type of process being marketed MSW Pretreatment Aerobic Drying Screening & Refining SRF Fe & non Femetals Commercial status on MSW feedstock No plant yet built Pilot Plant Demonstrator plant Commercial plant Advantages Disadvantages Key advantages & disadvantages commercial plant in operation treating MSW relatively simple system SRF being utilised in a long-term contract with cement kiln in Germany output from the operated process configuration is not fully bio-stabilised, which could cause an issue if the SRF has to be stored/landfilled the bio-drying process could be a net energy user market nervousness about viability of outlets for SRF Contact details Nehlsen AG, Engineering department, Furtstraße 14 16, Bremen, Germany. Tel: Fax: Key contact Bernd Oberländer Head of Engineering Department bernd.oberlaender@nehlsen.com

24 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-233 NEHLSEN Overview D Karl Nehlsen GmbH & Co. KG, based in Bremen, has been in the waste disposal market for over 75 years, and is part of the Nehlsen group, which consists of 12 companies with over 6,000 employees and reports an annual turnover of about 200M. In addition to supplying an MBT process, the group provides a wide range of waste management, recycling, waste transport and logistic services. The main business focus is integrated waste disposal for all types of wastes and they promote a so-called 3-Column Concept (3-Säulen-Konzept) covering MBT, incineration and landfill disposal. D The Nehlsen process is known as Mechanical Biological Stabilisation (MBS). We understand that Nehlsen developed the process themselves and that the German company Contec-Nord was bought by Nehlsen to make the bio-drying containers. D The term stabilisation is used to describe the process because the biodegradable waste is not fully digested as in conventional composting systems (see Annexe A). Instead it utilises the heat produced by the biological activity of the waste, held under aerobic conditions, to drive off moisture and other volatile compounds: the main aim being to produce an SRF. D The SRF is branded as Calobren and it is currently being used in a cement kiln in Germany. Because no water is added to the waste in the biological step, digestion is stopped when the moisture content of the waste falls below a certain level. However, waste digestion (decay) will resume if the moisture level is increased - an important issue to consider if this material has to be transported, stored or landfilled. D The Nehlsen process offering is very similar to that marketed by Herhof and we understand that there was some dispute between the two companies concerning the ownership of the underlying IPR (Intellectual Property Rights). We were told by Nehlsen that they have an understanding with Herhof s new owners in Ireland to market the technology at different scales: Nehlsen promoting smaller capacity systems of about 50,000 Tpa, operated on a one-shift system (plants operated on a 2 or 3-shift system will have higher capacities), and Herhof promoting larger plants. D The Rügen plant is relatively small and is fairly basic in the way it is configured. The operator can add capacity relatively easily by increasing the number of stabilisation containers that are used and we observed during our visit that newer container designs were being incorporated into the process for testing and operation (see Figure D169). The SRF refining stage is less advanced than in other systems we observed during visits to reference plants offering a similar technology approach, but we were told that the degree of refining was sufficient for the current outlet for the material, which is discussed later in this review.

25 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-234 NEHLSEN Figure D169: Nehlsen MBT plant in Rügen, Germany Newer container design attached to the process Bio-drying container Source: Photograph taken by Juniper during site visit Status of Technology Figure D170: Nehlsen s reference plants treating residual MSW Location Plant Capacity, Tpa Current Status Startup Rügen, Germany 20, Flensburg, Germany 25,000 No longer being built (see below) Lübben, Brandenburg, Germany 28, Stralsund, Mecklenburg- Vorpommern, Germany 70, 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 Nehlsen s information D The company operated a 2,000 Tpa pilot scale plant in 1998 for about 1 year at the Institut für Kreislaufwirtschaft in Bad Doberan, Germany. They built their first commercial MBT plant in Rügen (20,000 Tpa), North East Germany in 1999, which they operate themselves. The company secured follow-on orders for slightly larger facilities

26 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-235 NEHLSEN in Lübben and Flensburg, and a significantly larger plant in Vorpommern, all in Germany, with completion dates in 2005 (see Figure D170). D The plant originally planned for Flensburg will no longer be built. Instead the company will fulfil the waste management contract by transporting the waste from Flensburg to the Biodegma 200,000 Tpa reference plant in Neumünster, which is currently under construction. The main output from this plant would be an SRF, which will be processed in a nearby combustion facility also currently being constructed. Nehlsen is a part owner of the company that will operate the Neumünster facility. The company explained that the decision not to build their technology at Flensburg was strategic and allowed them to guarantee markets for the SRF at the time of arranging the waste management contract. Nehlsen stressed that the move was not because of technical or planning issues in Flensburg. The Process Figure D171: Nehlsen process as operated in Rügen, Germany Residual MSW Bulky waste to landfill Magnetic Separator Eddy Separator Vibrating Screen Shredding < 40mm <10 mm Aerobic Drying Trommel Fe-metals Non Femetals Rejects >200mm mm Off gases to biofilter Shredder Air separator Magnetic separator Eddy separator <50 mm Pelletiser Air separator Magnetic separator Granulator Rejects to landfill SRF Calobren Fe-metals KEY Recyclables Further Upgrading Emissions Residue Stream Source: Juniper representation of Nehlsen s information

27 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-236 NEHLSEN D D The incoming residual waste, which has undergone a degree of source-separation, is first visually inspected to remove oversized and unwanted items, which are sent for landfilling. The remaining waste is shredded to <300mm and then conveyed directly into the aerobic drying containers, where it undergoes bio-drying for about seven days at temperatures up to 70 0 C. These containers are aerated by a mixture of fresh air through under-floor air channels and by recirculated, de-dusted air from the SRF screening and refining stage. The offgases from the bio-drying containers are collected via a negative air pressure system and piped to a biofilter for odour removal. D Nehlsen informed us during our visit to the Rügen plant that the new German regulations (30 th BlmSchV) will require the installation of a thermal oxidation system at this site before 2006 for the process to meet the required VOC emissions levels. Because of the high investment costs associated with this upgrading, the company is considering the option of closing this relatively small facility and re-directing the waste to the nearby plant in Stralsund, which is currently being built. Both of the new plants currently under construction will include thermal oxidation of the off-gases from the stabilisation containers. D During bio-drying the waste loses about 25-30% of its weight. This weight loss is rapid over the first few days in the bio-dryer (see Figure D172). Figure D172: Typical operating profiles in the Nehlsen bio-drying process Weight loss, % Decrease in weight, % Temperature Temperature, 0C Number of days Source: Adapted from Nehlsen s data D The bio-dried materials are sent to a screening and refining stage. In this stage the material is divided into three size cuts by a trommel screen: <40mm, mm and >200mm. D The fraction >200mm is shredded to mm and joins this size cut after the trommel. The fraction <40mm is passed through magnetic and eddy current separators to recover

28 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-237 NEHLSEN ferrous and non-ferrous metals respectively and then through a screening stage to remove fines (<10mm). D The fraction mm is passed through an air separator to extract heavy items, which are sent to landfill. The lighter materials are then granulated and combined with the fraction >10mm recovered from the trommel cut of <40mm. The combined stream is passed through another air separator and then pelletised and sent to storage to be offered as an SRF product. This product is reported to contain less than 20% moisture and a net calorific value in the range 12-17MJ/kg. D The fraction <50mm passes through magnetic and eddy current separators to recover additional ferrous and non-ferrous metals respectively. The remaining materials are either mixed with the SRF product or sent to landfill. D For the Nehlsen plants that are currently being built, the SRF materials from the two streams (<40mm and mm) could be kept separate and may be marketed as different SRF products. Process Performance D The mass balance for Nehlsen s bio-drying process operated at Rügen is shown in Figure D173. Based on this balance, the waste diversion potential has been calculated and summarised in Figure D174 along with the relevant assumptions that have been made in the calculations. Figure D173: Typical mass balance for Nehlsen s bio-drying process Off-gases (incl. water vapour) (25 %) Residual waste (100%) Aerobic Drying Screening & Separation Bulky rejects Fe-metals (4%) Non Fe-metals (1 %) KEY Note: Stream to landfill includes inerts such as glass. Further Residue Recyclables Emissions Upgrading Stream Residues to landfill (15 %) SRF (55 %) Source: Juniper analysis of Nehlsen data

29 MBT: A Guide for Decision Makers - Processes, Policies & Markets Page D-238 NEHLSEN Figure D174: Landfill diversion potential (by mass) of the Nehlsen bio-drying process Diversion Potential Minimum, % Maximum, % Basis of Estimation Percentage of the input waste diverted from landfill Min: SRF to landfill, residues to landfill Max: SRF is used for energy recovery, residue stream 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 D Because all of the SRF from the Rügen plant is currently being utilised in cement kilns under contract arrangements, the current diversion of biodegradable waste (BMW) from landfill is likely to be greater than 85%. Energy Requirements D The bio-drying process is a net energy user but if the SRF is utilised, there will be an overall net energy gain. No further energy balance data was made available for review. Process availability D The Rügen plant is run on a one-shift basis for eight hours per day, five days per week, with one-hour per day being used for cleaning and maintenance. This translates to about 225 days per annum operation out of a possible 260 days and is equivalent to an availability of about 87%. However, at the time of writing, actual availability data for the plant had not been made available to us for review. Process Flexibility Process Scale D The Nehlsen bio-drying technology has operated at a 2,000 Tpa pilot plant and a 20,000 Tpa commercial plant. The commercial scale plant utilises 20 bio-drying containers or modules, each with a capacity of 1,000 Tpa. The process has been tested at this scale and has operated with some success commercially with this modular capacity. We therefore do not expect scale-up issues if the company continues to implement its technology in this way for the medium scale capacities proposed. Output Materials D Figure D175, based on the Rügen plant, gives the quantities of outputs that can be obtained from the Nehlsen process. This gives some indication about the amounts of various streams that will have to be managed if this process is implemented for treating similar types of waste.