Life Cycle Assessment of Waste Conversion Technologies

1. Life Cycle Assessment of Waste Conversion Technologies April 15, 2004

2. Outline • Background and goals • Overall approach • CT material and energy balance models • CT life cycle inventory models • Scenario analysis • Key findings

3. Background • AB 2770 included the requirement that the CIWMB’s report on CTs “describe and evaluate the life cycle environmental and public health impacts of CTs and compare them with impacts from existing solid waste management.”

4. Goals • What are the life cycle environmental impacts of CTs and how do these compare to existing MSW management practices? • Landfill • Waste-to-energy • Compost

5. Overall Approach • Define CTs: • Acid hydrolysis • Gasification • Catalytic Cracking • Develop material and energy balance for CTs • Develop life cycle inventories for CTs • Utilize CT inventories and RTI’s solid waste model to analyze future scenarios

6. Energy and Materials Production Fuel and Electricity Production Energy and Materials Production Fuel and Electricity Production Energy and Materials Input Energy Input Energy and Materials Input Energy Input Conversion Technology Subsystem Waste Generated Waste Collection Conversion Technology (e.g., gasification) Pre-processing (if needed) Conversion technology Up-front MRF Collection Land Disposal Land Disposal (e.g., gasification) Emissions Emissions Emissions Energy CT Byproducts Recyclables Electricity or Fuel Offset Recycling Offset Beneficial Use Offset Overall Boundaries

7. Material and Energy Balance Models • Developed using ASPEN Plus • Used publicly available information • Patent applications • Responses to UC questionnaire • Communicated with CT vendors • Employed conservative assumptions

8. Acid Hydrolysis

9. Gasification

10. VOC Emissions Water Wastewater Catalyst Feed Feed Baled Plastic Melting Spent Catalyst & Cracker Shredding Cleaning Contaminants Combustion Air Pollution Emissions Gas Control VOC Distillation Turbine Emissions Electricity for Internal Use Diesel VOC Emissions Storage Electricity Catalysts Spent Catalyst Diesel Product Ammonia Combustion Air Catalytic Cracking

11. Scenario Analysis • Analyzed future CT scenarios as defined by the Board in the RfP: 2003: three 500 tpd acid hydrolysis plants, four 500 tpd gasification plants, one 50 tpd catalytic cracking plant 2005: one additional 500 tpd gasification plant 2007: two additional 500 tpd acid hydrolysis plants 2010: one additional 500 tpd gasification plant

12. Waste Management Scenarios Compared • Landfill: • Gas venting (worst case) • Gas collection and flare (average case) • Gas collection and energy recovery (best case) • Waste-to-energy • Compost (organics only) • Conversion technologies

13. Landfill Scenario Mixed WasteCollection 50% Mixed Waste Transfer Station Landfill with landfill gas-to-energy 50% direct hauled Electricity Production

14. WTE Scenario Mixed WasteCollection 50% Mixed Waste Transfer Station Waste-to-Energy Ash Landfill 50% direct hauled Electricity Production Steel Recycling

15. Compost Scenario Organic Wastes Organics Composting Mixed WasteResiduals 50% Mixed Waste Transfer Station Landfill with Gas Collection and Flaring 50% direct hauled

16. Gasification Scenario Co-Located MRF/CT Facilities Mixed WasteCollection Upfront-MRF(95% sep. efficiency) Gasification Landfill with Gas Collection and Flaring MRF Residuals 45% Glass 25% Metals Recovered Materials to Recycling Electricity Production 50% Glass 70% Metals

17. Acid Hydrolysis Scenario Co-Located MRF/CT Facilities Mixed WasteCollection Up-Front MRF (95% sep. efficiency) Acid Hydrolysis Landfill with Gas Collection and Flaring MRF Residuals 45% Glass 45% Plastic 25% Metals Recovered Materials to Recycling Ethanol Production 50% Glass 50% Plastic 70% Metals Gypsum Byproduct

18. Co-Located MRF/CT Facilities CommercialCollection (presorted plastic only) 50% Up-Front MRF(95% sep. efficiency) 50% Catalytic Cracking Landfill with Gas Collection and Flaring Mixed WasteCollection MRF Residuals 45% Glass 45% Paper 25% Metals Recovered Materials to Recycling Diesel Production 50% Glass 50% Paper 70% Metals Catalytic Cracking Scenario

19. Co-Located MRF/CT Facilities CommercialCollection (presorted plastic only) 50% Up-Front MRF(95% sep. efficiency) 50% Catalytic Cracking Landfill with Gas Collection and Flaring Mixed WasteCollection MRF Residuals 45% Glass 45% Paper 25% Metals Recovered Materials to Recycling Diesel Production 50% Glass 50% Paper 70% Metals Example Mass Balance Datato LCI for Catalytic Cracking

20. Materials and Energy Inputs

22. Materials and Energy Outputs

24. Life Cycle Inventory For Catalytic Cracking Process

26. Life Cycle Inventory For Entire Catalytic Cracking Waste Management System

28. Key Findings • The amount of energy produced by the CTs is significant. • For criteria air pollutants, the CTs are not necessarily better than existing options. • From a climate change perspective, CTs are generally better than existing management options except for WTE. • Inadequate data to assess the potential for CTs to produce emissions of dioxins/furans and other hazardous and toxic pollutants. • Similar to recycling, CTs will likely result in greater local environmental burdens and a potential reduction in regional or global burdens.

29. Key Findings (cont.) • It is important for CT facilities to achieve high levels of conversion efficiencies and materials recycling. • CTs can decrease the amount of waste disposed of in landfills. • CTs can increase materials recovery and recycling with large associated benefits. • CTs are not equal in terms of life cycle environmental performance. • No CT facilities exist in the U.S. for MSW and therefore there is a high level of uncertainty regarding their environmental performance.

30. Limitations • CT facilities don’t exist in the U.S.: • Limited data • Uncertain feedstock composition • Uncertain pollution control requirements • An LCA is not a risk assessment: • Pollutants are totaled across time and locations • Concentrations of pollutants at a given time and location are not captured by a life cycle study

31. Sensitivity • Feedstock composition • Conversion efficiency • Level of additional recycling achieved versus pass through of inert materials to landfill • Pollution control devices and required inputs