Environmental impacts of plastic waste recovery

Transcription

1 Environmental impacts of plastic waste recovery Tuuli Myllymaa Finnish Environment Institute (SYKE), Research programme for production and consumption (TTO) RePlast Closing Workshop Dipoli

2 Structure of the presentation Methodology in the environmental impact assessment studies Plastic as a material flow in Finland from material cycle perspective Material recovery of plastics Energy recovery of plastics Conclusions Environmental impact assessment studies in SYKE

3 Methodology in the environmental impact assessment studies The environmental impacts are assessed with Life Cycle Assessment (LCA) methodology Ecobalance of all possible emissions from the processes, transportations and energy consumption throughout the whole product chain Scenarios/Ecobalances are compared to reference situation, that estimates what actions would take place, if we do this differently? from burning to recycling, etc.. Credits and Setbacks are summed up, Results, assumptions (!) and uncertainties (!!) reported clearly

4 *RePlast FinEst-project VAIHE II Report ** FINWASTE, ***YTV mixed waste sorting tests Plastic flows in Finland from material recovery perspective The main leak of plastic from the material cycle is to landfill, in mixed waste Uusiutuvat luonnonvarat Oil and natural gas, (inc.import) Uusiutum. 746 luonnonvarat kt Export 429 kt* Import, 273 kt* Jätteet Export, 7? kt** Sivutuotteet Energia Jätteet Kaatopaikka Uusioraaka-aineet Alkutuotanto, Production In jalostus, Finland, 654 palvelut kt* Products Waste 150*-200 kt* 273 Tuotteet kt* Consumption Waste Jätteet In hhw, Jätteet Waste Kulutus Jätehuolto 225 kt* kt* 13 %*** management 498 kt* Uudelleen- ja Energy uusiokäyttö 46 Energia kt* Kaato Energia Landfill Uudelleen- Reuse,? ktja paikkakt uusiokäyttö Material recovery, tysmateriaalit 21 kt*

5 Recovery of plastic in mixed waste More efficient source separation of plastic and fiber containers into energy fraction Needs mechanical processing before incineration, E << 1 MJ/kg Lower heating value of REFIII = MJ/kg Quality of separation varies, yeald varies Mechanical processing of mixed waste into energy fraction Mechanical processing, E < 1 MJ/kg Lower heating value of RDF = MJ/kg Source separation of plastic waste for material recycling Efficiency and yeald?

6 Material recovery of plastics 1/2 Energy, GJ kg CO2-ekv Transports Total amounts per 1000 kg of product tkm kg CO2-ekv kg CO2-ekv/t Virgin plastic production Indicative results Waste plastic productisation Virgin plastic production Crude oil extraction and refining Naphta Natural gas extraction and processing Natural gas Waste plastic productisation Crushing of plastic waste Cracking process Ethylene Polymerisation Washing of plastic crush Granulation HDPE-plastic granulate Plastic product HDPE-plastic granulate Transportation

7 Material recovery of plastics 1/2, to notice Environmental impacts can be reduced by replacing virgin plastics with waste plastics Energy balance Saving of non-renewable resources oil and natural gas The role of transportation remains decent To notice: the energy content of plastics raw materials are over 50 GJ/t

8 From: Hiltunen&Dahlbo 2007 Material recovery of plastics 2/2 Energy, GJ kg CO2-ekv Transports After life Total amounts per 100 m2 of product kg CO2-ekv combustion kg CO2-ekv Plastic profile production and combustion n.a Impregnated wood production and combustion n.a Plastic profile Impregnated wood

9 Material recovery of plastics 2/2, to notice In comparison to impregnated wood, the plastic recovery comes second in GHG-emissions Biogenic CO2-emissions of wood can be left out In toxic impacts the plastic profile would propably beat the impregnated wood Metal-based compounds in impregnation fluids Not included in the study, though

10 Energy recovery of plastics Assumed Finnish energy profile for energy prod. in areal scale is: Heat energy: decrease the use of areal heat boilers, that use oil (or peat). Electricity: replace coal condensate power Virgin fuel incineration Oil extraction and refining Oil Coal extraction and processing Coal Waste plastic incineration in REF1-2 co-combustion plant Collection and transportation of plastic waste Crushing of plastic waste 79 kg CO2-ekv/GJ Oil burning Coal burning 95 kg CO2-ekv/GJ Waste plastic burning 74 kg CO2-ekv/GJ Electricity 1/3 33 GJ/t Heat 2/3

11 Energy recovery of plastics, to notice Plastic is a valuable fuel with high energy content But when mixed with other wastes, like mixed waste, can contain impurities, that could be harmfull for both the boiler and to the environment From 20 to 30 % of incinerated material is still present as ash, that must be handled and taken to final disposal

12 Conclusions 1/2 The ghg-savings per tonne are bigger when recovering plastics as material than as energy Depends mostly on the energy assumptions Energy, GJ kg CO2-ekv Transports Total Savings amounts per 1000 kg of product tkm kg CO2-ekv kg CO2-ekv kg CO2-ekv Virgin plastic production Indicative results Waste plastic productisation Energy, GJ kg CO2-ekv Transports Total Savings amounts per 1000 kg of product tkm kg CO2-ekv kg CO2-ekv kg CO2-ekv Virgin fuel incineration, oil+coal (inc. Extr.) n.a 2836 n.a 2836 Waste plastic incineration n.a Indicative results Indicative results In comparison with biogenic products, the ghgsavings of wood beat the waste plastic other aspects like avoided metal impacts gives some compensation

13 Conclusions 2/2 Huge plastic potential in mixed waste Landfilling causes no emissions, but all the potential benefits are lost Challenges in getting it out with suitable quality => Markets and need for mechanical processing development? The data quality causes uncertaintities into results, the magnitude not assessed yet

14 Environmental impact assessment studies in SYKE Environmental and economic impacts from recycling of combustible wastes (POLKU) Ongoing project (SYKE, TUT, HUT, ÅA) Reducing Greenhouse Gas Emissions by Recycling Plastics and Textiles into Products (UJKON) Finished project (VTT, SYKE) Optimum lifecycle for shopping bag Minimization of greenhouse gases in the product chain (OPTIKASSI) Project proposal for Tekes 9/2007 (SYKE, LUT)

15 Thank you!