MPACT ASSESSMENT
An environmental impact assessment of the full super-clean recycling process was conducted using Life Cycle Assessment (LCA) methodology. Possible environmental impacts of the system using this recycling process were compared with the impacts of a reference system. The reference system was defined as the deposition of the post-consumer waste in a landfill site (‘standard waste management system).
SYSTEM BOUNDARIES All relevant process steps were taken into account – from the collection of post-consumer waste up to the production of recycled HDPE for re-use or final disposal respectively. For the recycling scenario the following relevant processes were examined: collection , sorting , washing super clean recycling
For the reference scenario ‘landfill disposal’:collection final disposal
LIFE CYCLE INVENTORY For all processes including power supply and transportation detailed input/output descriptions were used including amount and specification of input material, products and waste amount of electrical power, waste emission into air and water sorting and preparation losses etc.
ENVIRONMENTAL IMPACT ASSESSMENT
Impact categories results of the LCA are presented in the following environmental category primary energy equivalent (in MJ/1000 kg used milk bottles)global warming potential (in kg CO2-Equivalents/1000 kg used mild bottles) acidification potential (in mol SO2/1000 kg used mild bottles) eutrophication potential (in mol PO4/1000 kg used milk bottles)amount of waste ( in kg/1000 kg used milk bottles)
LCA RESULTS Primary energy equivalent PET the primary energy consumption of the recycling scenario was 25000-30000 MJ /1000 kg milk bottles less than for the reference scenario.That is the PE consumption is 6000 to 7000 MJ / 1000 kg of milk bottles.
GLOBAL WARMING POTENTIAL
GWP The difference in global warming potential between the recycling and reference scenario is about 500 kg CO2 / 1000 kg milk bottles.That is the global warming potential was 1700 to 1800 kg of CO2/ 1000 kg of milk bottles. Emission of CO2 Eutrophication Potential EP Road transportation is a major cause of eutrophication (smog formation)The difference between the recycling and reference scenario is about 1-6 mol PO4/ 1000 kg milk bottles.That is the emission of PO4 was 2 mol PO4/ 1000 kg milk bottles. Acidification Potential APFor AP too the most important effect on the difference between recycling and reference system comes from the choice of HDPE-data used in the reference system.The difference is 30-160 mol SO2 /1000 kg milk bottles.That is the emission of SO2 was 20-30 mol of SO2 / 1000 kg milk bottles.
Municipal Solid Waste
MSW Depending on recycling efficiency the amount of waste for disposal is 400-500 kg / 1000 milk bottles less than in the reference system.That is the municipal solid waste is 45000 kg/ 1000 kg of milk bottles.
Use of Water
The difference in water between the two processes is about 20 cubic meter / 1000 kg of milk bottles.That is the consumption of water is 15 to 16 cubic meter / 1000 kg of milk bottles.
LIMITATIONS AND CONCLUSIONS
This analysis assumes that the HDPE recyclate produced by the super-clean process can be used as a direct replacement for virgin HDPE polymer. If the recyclate can only be used in lower applications then the conclusions of the LCA will not be valid.The analysis also assesses the environmental impact of the two scenarios in a limited range of impact categories and for a limited range of process conditions. No LCA can assess all possible impacts on the Environment or all possible process conditions.Taking these factors into account the following conclusions can be made: HDPE recycling via the developed bottle to bottle recycling process causes less impact on the Environment than landfill disposal in the impact categories examined for this project. The impacts avoided by the bottle to bottle recycling of 1000 Kg milk bottles rather than landfill disposal are equivalent to the impacts caused by the production of about 300 kg virgin HDPE material.With the exception of sophistication potential category, transportation distance and energy consumption for the recycling processes are of minor importance for the results. Higher losses in the upstream sorting and preparation processes reduce the positive effects on the environment. For good positive, a high recycling efficiency must be realised. A report on the production of carrier bags made from recycled rather than virgin polythene concluded that the use of recycled plastic resulted in the following Environmental benefits:* reduction of energy consumption by two-third production of only a third of the sulphur dioxide and half of the nitrous oxide reduction of water usage by nearly 90%reduction of carbon dioxide generation by two-and-a-half times A different study concluded that 1.8 tonnes of oil are saved for every tonne of recycled polythene produced.Impacts associated with the transport of materials to and from the facility, use of non-renewable resources, energy use, odour, noise, dust and water quality.
The post-use HDPE milk bottle’s to procure from the city councils and their collection centers, warehouses; it does not affect any much of environmental effect because it is not the new process of disposal. The transport of this material to the Black Country area is not far from the city.Mitigation of Environmental Impacts Environmental Impacts can be mitigated by adopting good housekeeping, good engineering, and maintenance which involves operational improvements or administrative changes. This reduces costs without incurring significant investment. Examples include ·
LIMITATIONS AND CONCLUSIONS
This analysis assumes that the HDPE recyclate produced by the super-clean process can be used as a direct replacement for virgin HDPE polymer. If the recyclate can only be used in lower applications then the conclusions of the LCA will not be valid.The analysis also assesses the environmental impact of the two scenarios in a limited range of impact categories and for a limited range of process conditions. No LCA can assess all possible impacts on the Environment or all possible process conditions.Taking these factors into account the following conclusions can be made: HDPE recycling via the developed bottle to bottle recycling process causes less impact on the Environment than landfill disposal in the impact categories examined for this project. The impacts avoided by the bottle to bottle recycling of 1000 Kg milk bottles rather than landfill disposal are equivalent to the impacts caused by the production of about 300 kg virgin HDPE material.With the exception of sophistication potential category, transportation distance and energy consumption for the recycling processes are of minor importance for the results. Higher losses in the upstream sorting and preparation processes reduce the positive effects on the environment. For good positive, a high recycling efficiency must be realised. A report on the production of carrier bags made from recycled rather than virgin polythene concluded that the use of recycled plastic resulted in the following Environmental benefits:* reduction of energy consumption by two-third production of only a third of the sulphur dioxide and half of the nitrous oxide reduction of water usage by nearly 90%reduction of carbon dioxide generation by two-and-a-half times A different study concluded that 1.8 tonnes of oil are saved for every tonne of recycled polythene produced.Impacts associated with the transport of materials to and from the facility, use of non-renewable resources, energy use, odour, noise, dust and water quality.The post-use HDPE milk bottle’s to procure from the city councils and their collection centers, warehouses; it does not affect any much of environmental effect because it is not the new process of disposal. The transport of this material to the Black Country area is not far from the city.Mitigation of Environmental Impacts Environmental Impacts can be mitigated by adopting good housekeeping, good engineering, and maintenance which involves operational improvements or administrative changes. This reduces costs without incurring significant investment. Examples include ·
Clear specification of good housekeeping and materials handling the procedure.
· Implementing quality assurance technique
· Regular auditing of materials purchased against materials used
· Avoidance of over-ordering
· Regular preventive maintenance
· Segregation of waste stream to avoid cross-contamination of hazardous and non-hazardous materials, and to increase recover-ability
· Reduction in the volume of wastes by filtration, membrane process, vaporisation, drying, and compaction
· Elimination of poor storage conditions.
· Introduction of employee training and motivation scheme for waste reduction environmental Improvements;
It is important that proper attention is given to minimising spills, leaks, contamination during the storage of raw material, products, and process wastes and the transfer of these materials within the production facility. Examples requiring attention are ·
· Leaking valves, hoses, pipes, and pumps.
· Leaking tanks and containers.·
· Overfilling of tanks, inadequate, poorly maintained or malfunctioning high-level protection.
· Leaks and spills during material transfer. ·
· Inadequate binding;·
· Leaking filters, bunkers and bins in
· powder transfer operations.
· Equipment and tank cleaning operation.
· Lack of regular maintenance, inspection, and operator training·
· Correct sequencing of valve operations.
· A fundamental change to or better control of process operating conditions such as flow rate, temperature, pressure, residence time and stoichiometry to reduce waste and consume less raw materials and energy
· Redesign of equipment and piping to reduce the amount of material to be disposed of during start-ups, shutdowns, product changes and maintenance programmes.
· Installation of vapour recovery systems to return the emissions to the process.
· Use of more efficient motors and speed control systems to reduce energy consumption