3.0. Site Selection, Technology Selection and Project Description.

Transcription

1 3.0 Site Selection, Technology Selection and Project Description

2 Site Selection, Technology Selection and Project Description 3.1 Site Selection 3.2 Technology Selection 3.3 Project Description 3.4 Access 3.5 Construction Phase Site Selection During the exploratory stages of the proposed Scheme, a search was made for potential sites:- The criteria used in comparing the merits of each of the potential development sites were: - Size (area, footprint, dimensions) Minimum 2500 square meters of internal floorspace; Existing Industrial/Brownfield land if possible; Existing permissions, classifications and designations for industrial use; Proximity to port facilities / commercial port of Limassol; Site Accessibility by Road; Physical proximity to service infrastructure Potential for Environmental Impact; Site availability. Lease notices and market knowledge were used to identify and screen potential sites that could have been adopted for the development. The Limassol site was preferred as it satisfied each of the criteria outlined above and: 1. The total unit area allowed sufficient space to accommodate both processes, 2. The unit is within an existing industrialised area 3. The site was available for immediate lease 4. The existing infrastructure supported the nature of the development in particular the availability of the nearby port facilities and good road links 5. The site does not lie adjacent to any designated or protected habitats 6. The site already had a general license for the collection and recycling of waste paper 3.2 Technology Selection Aluminium Recycling of scrap aluminium provides a valuable resource and prevents the material from being diverted to landfill. The Zeme system will be utilised to produce high quality aluminium alloy ingots which will be available for re-use within industry. The melter is electrically inducted to raise it to operational temperature and will always retain a residual layer of molten aluminium, approximately ¼ of the total volume, within the smelting pot when operational. Aluminium feedstock will be added to the pot with ¾ of the melt volume then periodically cast into aluminium ingots. The Induction furnace equipment for the processing of aluminium feedstock is of industrial standard design for the type of process proposed. The furnace design and process control has been refined to optimise output and reduce emissions compared to other equipment and operating techniques. Consequently no alternative technologies were considered.

3 13 Plastic Conversion The thermal cracking equipment will convert a material likely destined for landfill into low carbon liquid fuels. The machinery will utilise low Nox burners which will reduce emissions. The low Nox burners will start up on LPG (Liquid Petroleum Gas) which is a low sulphur fuel. The burners can then continue to run on LPG, but will also be capable of changing to operate on the low sulphur liquid fuel produced by the unit itself. The thermal cracking equipment is of a novel custom build design and consequently there are no alternative technologies which were considered. 3.3 Project Description A detailed process flow diagram of both processes is included in Appendix A. Process 1 Induction Furnace An induction furnace will be utilised to melt scrap aluminium (e.g. scrap, empty cans, tins), to produce various grades of aluminium alloys in the form of ingots. Induction furnaces are clean, energy efficient and are considered to be a very controllable melting process. The process is summarised in the flow chart, figure 3.1, and discussed further below: Delivery of aluminium feedstock Material shredded and washed Material dried and baled Material fed into induction furnace Material cast as ingots Ingots packaged for sale and onward transport figure Induction Furnace Process Summary Aluminium scrap will be delivered to the facility in bails and as loose aluminium scrap. The bails will be shredded and washed before passing through a drier to remove washing fluid and finally into an industrial drier to fully dry the material. The shredded, washed and dried material will then be re-compacted into bails for storage prior to melting. The aluminium scrap introduced into the furnace is made up of elemental metals in the aluminium alloys which include Aluminium, Silicon, Magnesium, Copper and Iron and a surface film of aluminium oxide. All feedstock material and products will be stored and processed inside the building on impermeable hardstanding. The washing fluid will be tested periodically and replenished as required. An induction furnace is an electrical device in which the heat is applied by water cooled induction coils. Two separate furnaces will be installed which will process 750kg of material each at a time. This will allow for a continuous process.

4 14 Each of the furnaces will retain a ¼ volume of molten aluminium at all times when operational. New material will be added to the furnace and melted, with the molten material then being poured into ingots leaving the residual quarter volume within the melting pot. Silicon will be added to the furnaces as an alloying element and Flux will be added to reduce melt oxidation in the process. The flux is a eutectic blend of sodium and potassium chloride, which melts at 580º centigrade. The molten flux dissolves the aluminium oxide film on the surface of the scrap being melted allowing the molten aluminium to coalesce. The solution of flux and aluminium oxide gathers on the surface of the melt and can be skimmed off prior to pouring the molten aluminium into the ingot moulds. The elemental metals do-not chemically change during the melting process. Elemental silicon will be added to the molten aluminium to dissolve in the molten metal and be assimilated into the alloy. Any particulates or vapours released during the melting operation will be collected by lip extraction vents on both melting units. The main emission is expected to be fine aluminium oxides. Any particulate matter produced and removed by the lip extraction system is designed to be retained by the Venturi Type wet scrubber system that will be installed at the site. However, the atmospheric dispersion model in section 5 has modelled the potential emission from any particulate produced, which was shown to be below published limits. The emission will be scrubbed prior to release to the environment via a 15m high stack Dross will be removed from the surface of the furnace prior to casting. The dross will be retained inside sealed containers while it cools to prevent any emissions to air. The dross will be sent off site for further processing or to a suitably licensed facility for recycling/disposal. The Aluminium melts will be sampled in accordance with European Standard EN14361:2004 and analysed in accordance with EN14242:2004. The alloys produced in the main will conform to the Aluminium casting alloys included in European Standard EN1706:2010. Process 2 Thermal Cracking of Plastics The second process enables recovered plastic to undergo thermal cracking and conversion into a usable liquid fuel, similar to diesel. The process is summarised in the flow chart, figure 3.2, and discussed further below: Delivery of plastic feedstock Material shredded Material fed into thermal cracking equipment Material condensed to liquid product Liquid product stored in tanks prior to onward transport Figure Thermal Cracking Process Summary

5 15 The plastic material will arrive at the site in bails or in bulk bags. The material will pre selected and not heavily soiled. Heavily soiled material will be rejected. Plastics to Liquid Fuels The Zeme facility will treat Clean Plastic films and packaging material segregated from municipal waste. The plastics specified for use in the Zeme Facility will include the following thermoplastics: Polyethylene (PE); Polypropylene (PP); Polystyrene (PS); Polyester (PET). The facility will also have specifications to minimise the level of contaminants entering the facility either on the surface of the plastics or within the chemical makeup. Virgin Plastic prior to processing contains very low concentrations of contaminants such as: Sulphur; Halides (Chlorides and Bromides); Metals. The contaminants within the chemical structure of the plastics come from additives which are designed to modify the properties of the plastics. The thermoplastics typically found in the packaging materials in Municipal waste may contain the following functional additives: Flame retardants; Colourants; Fillers (mica, talc, kaolin, clay, calcium carbonate, barium sulphate). Flame retardants Flame retardants are typically added to industrial and consumer products to meet flammability standards for furniture, textiles, electronics, and building products like insulation. There are three main types of flame retardants used in thermoplastics: Chlorinated organic compounds; Boric Acid; Brominated organic compounds. The uses of the following Flame retardants are: Chlorinated organic compounds This type of fire retardant is added to PVC in the USA according to [POPRC, 2007] it is not used in PVC in Europe, but primarily in rubber and elastomers (sealants etc.) polymer textile fibres and cover cellulosic textiles. They are not normally used in film plastics for packaging. Boric acid This fire retardant can be used as flame retardant for polystyrene beads and components. It is not used in packaging materials. Brominated organic compounds This type of Fire retardant is used in ABS, EPA, HIPS, polyamides, PBT, polyethylene, polypropylene, epoxy, unsaturated polyester and polyurethane. Brominated flame retardants are frequently used in Brown goods such as television sets, computer hardware housings and monitors, etc, polystyrene foams and it is also used in some packaging but never for food products.

6 16 From the above it can be seen that the plastics that contain flame retardants are confined to areas where they can be exposed to very high temperature and sources of ignition. Therefore, building and construction is the main application followed by the electrical and electronics industries, automotive and furnishings. Their use in packaging is very limited and then is limited to Brominated Hydrocarbon. Colourants Colourants fall into two broad categories: pigments and dyes. Pigments are colourants that do not dissolve into the plastic, whereas dyes are colourants that do go into solution. Pigments are divided into organic pigments and inorganic pigments. Commonly used organic pigments are: phthalocyanine red, phthalocyanine blue, phthalocyanine green, light red, red molecules, macromolecules yellow, Permanent Yellow, Violet, azo red. Inorganic pigments commonly used are stable metal oxides such titanium dioxide, carbon black, iron oxide red, iron oxide yellow, etc. Inorganic pigments are mainly used for the production of surface coatings such as paints. Packaging plastics tend to be coloured by low cost low levels of organic dyes and pigment. The compounds do not contain halides. Inert Fillers Inert fillers are used to increase the stiffness and hardness of plastics. They will also reduce the cost of the materials as they are generally cheaper than the base polymer. Inert fillers include calcium carbonate, talc and barium sulphate. The use of fillers in packaging materials is very limited. Material Control The potential receipt of contaminants into the facility are in three forms: 1. Surface contamination of the plastics (Lack of cleanliness); 2. Presence of non-specified plastics such as PVC; 3. Presence of specified plastics which contain flame retardants. The suppliers of the waste plastics will be given the facility s specification which will specify that the receipt materials must be free from surface contamination and contain no PVC containing compounds. Materials will be inspected on receipt at the facility and non-conforming materials rejected and returned to the supplier. The likelihood of receipt of plastics that contain flame retardants is very low, as none of the selected plastics are normally exposed to high temperature uses. Should in the unlikely event that low levels of plastic with flame retardants enter the liquefaction system the majority, in excess of 95% by mass of halides in the retardant would be released as a gas and removed in the Venturi Type wet scrubber system prior to treatment in the facility s burners. Any remaining halides contained in the fuel oil would be at a very low trace concentration. The European standard EN590 and BS2869 specification for Diesel do not set a specific limit for halides, but it does set an upper limit of 24 mg/kg for other contaminants. This would include halides. The final product is expected to be well within this other contaminant concentration, with a target of less than 2mg/kg. The fuel produced will be batched and given a unique serial number. Each batch of fuel will be analysed to ensure that the halide and other contaminants meet the specification of EN590. If the halide levels exceed the specification, then that batch of fuel will be passed through a proprietry Alumina based dechlorination filter to remove the excess halides. The halide containing compounds bind to the filter.

7 17 After treatment the batch of fuel will be reanalysed which will allow the performance of the filter to be monitored and to determine when it becomes exhausted. Once the filter is exhausted it will be replaced and the spent filter will be disposed of to a suitably licensed facility. The desorbed chlorides will then be in the form of the sodium salts and be disposed of to a suitably licensed facility. The colourants in the treated plastic will be organic in composition and be de-polimerised and form part of the fuel or in the case of inorganic pigments or inert fillers in the plastic retained in the catalyst bed. The catalyst bed will periodically be cleaned by flowing the metal catalyst bead through a screen filter. The fine solid fillers and pigment will be extracted and disposed of to a suitably licensed facility. The expected levels are very low being less than 1% of the treated mass. The plastic will be shredded and then fed directly into the thermal cracking equipment, Shredding the plastic to form a feed material will help achieve a high liquid yield. All feedstock material and products will be stored and processed on impermeable hardstanding inside the building. The plastic feedstock material will be rapidly heated inside the reaction chambers to the cracking temperature with the breakdown products being collected and cooled rapidly to condense into a liquid fuel. The rapid heating of the shredded plastic will be achieved by mixing the plastic into a flowing bed of metal catalyst beads at a controlled temperature. The mass of metal catalyst acts as a high heat energy sink being able to release heat to the plastic rapidly, leading to an almost instantaneous rise in temperature to the cracking point. The chemical cracking breaks the large alkane chains in smaller alkane chain length molecules and is a form of de-polymerisation. The process use nickel metal alloy catalyst bead. These bead are not affected by the reaction that they catalyse and do-not undergo any chemical degradation. The metals in the catalyst alloys are not released into either gas stream or liquid fuels formed. The released vapour products will be held in the reaction chamber for varying lengths of time to achieve the desired carbon chain length, before being collected and rapidly cooled by passing through a tube condenser cooled by chilled water. The temperature of the flowing bed is controlled by the burners which indirectly heat each of the treatment beds. The rate of flow of the bed is controlled by the velocity of the motors driving the screws. The only gaseous emission will be those from the low NOx burner chambers, this will be released to the environment via a 15m high stack, following treatment in a Venturi Type wet scrubber. The vapour collected from the reaction vessels will be condensed and stored in suitable containers. The collected liquids will be analysed for various off site commercial uses. The cracking equipment will be able to process around 1 tonne of feedstock material per hour and is expected to produce in the order of liters of liquid product per hour. All material delivered to the facility will be checked by a site supervisor prior to acceptance and only material meeting the required standard will be accepted.

8 18 All materials, including any waste material and final product, will be stored within the building. Any fuel or liquids will be stored within either a double skinned tank, or in a tank located within a bund, which is capable of holding 110% of the capacity of the tank/s contained within it. The combustion products from the low NOx burners will be passed through a high efficiency Venturi Type wet scrubber prior to release to the environment via the stack. The fuel products will meet the relevant British Standards (BSs) European standards (ENs) and standards published by the European Committee for Standardization (CEN). The liquid fuel produced by the Thermal Cracking Process would be in general compliance with the following standards acceptable under european classification; Number 2 Fuel Oil BS2869 ASTM D 396 The Fuel quality would be very low sulphur Material and Processing Capacity The site will store a minimum volume of feedstock to allow 48 hours of continuous operation at any one time for each process. The material will be either in bails or will be stored within bulk bags. The feedstock will operate on a first in, first out system to ensure feedstock rotation. This process will also limit the potential of any fugitive emissions from unprocessed feedstock. Induction Furnace There will be two Induction furnaces with each having a capacity of 1 Tonne. Each furnace will retain a quarter of its volume (250kg) in molten material at any one time. Consequently each furnace will be capable of producing 750kg of ingots per production run. Each production run is expected to take up to 30 minutes to complete. It is therefore expected that around 72 Tonnes of aluminium ingots will be cast each day during continuous operation. Assuming a density of 1.5 Tonnes per cubic meter, this would equate to around 108 cubic meters of the raw unprocessed aluminium feedstock per day. Thermal Cracking Equipment The thermal cracking equipment will process 1 tonne of feedstock per hour which will produce between litres of liquid product. The process will therefore utilise 24 tonnes of feedstock per day which assuming a density of 200kg per cubic meter equates to 120 cubic meters of feedstock per day. The site will store a minimum volume of feedstock to allow 48 hours of continuous operation at any one time Feedstock Storage and Management All feedstock will be stored within the site building on impermeable hardstanding and will be processed on a first in, first out basis.

9 19 The feedstock processing equipment will be located within the building on impermeable hardstanding. A stringent specification for the material will be send to suppliers, which will include a requirement for the material to be odourless, as set out in section Normal building ventilation will therefore be adequate Wastes Gaseous Emissions All of the Gaseous emissions from both processes will be released, following treatment in a Venturi Type wet scrubber, via a new stack. The emissions from the stack are described in detail in Section 5 of this document. However, the relevant limits set by the European Union have been reproduced in figure 3.3 below, along with the emission levels at the Zeme facility calculated from the atmospheric dispersion model, which is included with the EIA. POLLUTANT AVERAGING PERIOD PERCENTILE BENCH-MARK PC % AGE NO X Hourly Mean % Annual Mean % SO 2 15 min. Mean % Hourly Mean % Daily Mean % Particulates (as PM10) Daily Mean % Annual Mean % Particulates (as PM2.5) Annual Mean % CO (mg/m³) 8 hour running mean % HCI Hourly mean % HF Hourly mean % Lead Annual mean % Benzene Annual mean % Figure 3.3 Maximum Predicted Ground Level Concentrations (ug/m³) The levels of gaseous emissions from the zeme facility are below the published limits for every determinand. The main gaseous emissions from the melter will be fine aluminium oxides which will be captured by a Venturi Type wet scrubber. The warm air from this extraction process will be released following treatment in the scrubber via the stack. The main gaseous emission from the plastic conversion equipment will be from the low Nox burners that will be used to heat the facility. The emissions will fall well below normal industrial emission guideline limits. The main components of the emission will be Carbon Dioxide, Oxides of Nitrogen and water. Induction Furnace The induction furnace is not expected to generate significant amounts of waste as the process melts and casts the feedstock into new ingots. The main waste from the process will comprise dirty water generated during the washing of feedstock prior to processing. The water will be contained within the washing machinery and reused until it has been spent, following which it will be renewed. The waste water will be taken off site for disposal at a suitably licensed facility by tanker.

10 20 The facility is expected to generate around 100 cubic meters per annum of contaminated water. The induction furnace will generate a small amount of dross, approximately 30 KG, which is a solid residue that is formed during the melting process. This material will contain metal and will have a value and will be sent for reprocessing in sealed shipping containers. The material will be removed from the site periodically once sufficient material to fill a shipping container has been produced. Thermal Cracking Equipment The thermal cracking equipment is not expected to generate significant amounts of waste. The plastic materials contain fillers and these will be liberated as solid or gaseous residues (such as Calcium Oxide and Carbon Dioxide) during the liquifaction process. Solid residues are recyclable and will be added to construction material production streams locally. It is likely that the system will produce around 88 tonnes of solid residue per annum. Gaseous residues will exit the system via the scrubber and have been accounted for in the air dispersion model. Wet Scrubber Efficiency Wet scrubbers that remove gaseous pollutants are referred to as absorbers. Good gas to liquid contact is essential to obtain high removal efficiencies in absorbers. When gas stream contains both particle matter and inorganic gases, wet scrubbers are generally the only single air pollution control device that can remove both pollutants. Wet scrubbers achieve high removal efficiencies for either particles or gases and, in some instances, can achieve a high removal efficiency for both pollutants in the same system. In general, obtaining high simultaneous gas and particulate removal efficiencies requires that one of them be easily collected (i.e., that the gases are very soluble in the liquid or that the particles are large and readily captured) or by the use of a scrubbing reagent such as lime or sodium hydroxide. Collection efficiencies for wet scrubbers vary with the particle size distribution of the waste gas stream. In general, collection efficiency decreases as the PM size decreases. Collection efficiencies for venturi scrubbers are typically around 99%. The Zeme facility will utilise Venturi Type scrubbers. In order to adopt a conservative approach, it has been assumed that the Zeme scrubber will have an efficiency of 95%.

11 21 Clean gas out Mist eliminator Dirty gas in Liquid in Throat Separator Elbow joint Liquid to settling and recirculation Waste Storage All wastes will be stored in appropriate containers on impermeable hardstanding within the building, prior to disposal off site to recycling facilities or to suitably licensed facilities. Any liquid material will be stored in a suitable container or tank, which will be on impermeable hardstanding and contained within a bund capable of holding 110% of the volume of the tanks/containers within it Site Modifications and Equipment specifications The equipment required for both processes will be housed within an existing industrial unit. The building will have a new separation wall constructed between the two processes and a new office block and laboratory will be constructed inside the existing shell of the building. A new weighbridge will be built in the driveway of the building. The equipment will be brought to the site in containers and will be assembled within the building using standard machinery and tools. A brief summary of the process equipment is given in Table 3.1 below. PROCESS Plastic to Liquid Fuel COMPONENT Shredder Plastic to liquid fuel conversion technology Aluminium alloy process Shredder Washing plant Drying plant Variable induction furnace and casting Chilling unit Joint Use Scrubber Stack Table Process Equipment Summary

12 22 The facility will require new service connections. The aluminium facility will require a new electricity connection to operate the induction furnaces. The connection will enter a new transformer that will be located within the building. The plastics conversion technology will run on low Nox LPG burners and low Nox liquid fuel burners. LPG and liquid fuel tanks will be provided adjacent to but outside of the building. 3.4 Access All vehicle movements relating to the operation of the proposed facility will enter the site via Epimitheos Road off Vertical Port Road. Once fully operational, the on-site workforce will be in the order of 30 people split over four shifts generating a maximum of 30 two-way vehicle movements a day, and approximately 7 8 in any given hour. The use of public transport will be strongly encouraged by considering public transport timetables when planning and implementing shift patterns, in addition to promoting the use of car-sharing, cycling and walking as much as practically possible. 3.5 Construction Phase The construction phase will primarily involve the installation of the process equipment within an existing building, with the exception of the emissions stack which will be installed on the outside of the building. Standard health and safety procedures and methodologies will be utilised.