— Case study of Tianjin, China

1. Comparison of green-house gas emission reduction and cost-effectiveness between two ways of waste-to-energy — Case study of Tianjin, China Yu He1,a, Yuan Wang1,b, Beibei Yan1,c, Meng Han2,d 1School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China 2Tianjin TEDA Environmental Protection Company Limited, Tianjin, 300350, China ariver_hey@tju.edu.cn, bw_yuan77@163.com, cbeibei.yan@163.com, dhmstar2570@126.com

2. 目 录 • Introduction • Calculation methods of GHG reduction • Cost-benefit analysis of WtE • Conclusions

3. Introduction • EU-15 emissions data(1990-2007) • 2.76%→29.7% • China（2010） • 158.05Mt MSW (Municipal Solid Waste) • 77.9% for harmless treatment Waste-to-energy (WtE) : ·Generate energy ·Reduce GHG emissions ①MSW quantity↑ Fossil fuel↓ ②GHG emissions：WtE ↓ Fossil fuel power generation↑

4. Auxiliary fuel and material consumption LFG GHG Electricity Landfill Bottom ash Electricity Heat Steam MSW GHG Incineration Leachate, Fly ash, Flue gas Disposal Substitution of fossil energy • Incineration with electricity (Incineration E) • Landfill with landfill gas utilization (Landfill E) Figure: System boundary of waste-to-energy research

5. Calculation methods of GHG reduction • IPCC & CDM • BASELINE SCENARIO： • Using landfill to disposal of MSW, the LFG generated by solid waste landfill directly discharge to the air without any treatment. • LFG：50%CH4 [Global Warming Potential(GWP) 21] 50%CO2 [Biological carbon，GWP 0]

6. Mass balance method： MSW is total amount of MSW which were landfilled, t; DOC is percentage of biodegradable organic carbon contained in MSW, identified by the components of MSW (According to the MSW composition in East Asia provided by IPCC, the DOC was 14.19%); r is decomposition rate of degradable organic carbon in MSW, IPCC recommended as 77%; 16/12 is molecular weight ratio of CH4/C; GWPCH4 is the multiple compared greenhouse effect produced by CH4 to CO2, as 21.

7. GHG reduction of Incineration E • In the absence of Incineration E projects, CH4 emission from MSW landfill; • In the absence of Incineration E projects, the average CO2 emissions of the local power plant. The amount of GHG emission reductions by Substitution of fossil energy: + (ETt,t · CEFt) The amount of GHG emission by burning of fossil carbon in MSW : Eincineration Fossil carbon The amount of GHG emission by combustion of auxiliary fuel:

8. GHG reduction of Landfill E • In the absence of Landfill E projects, MSW landfill emissions of CH4; • In the absence of Landfill E projects, the average CO2 emissions of the local power plant.

9. Private Environmental Gate fees / Tipping fees Local environmental problems Energy sales Benefit Carbon emission trading Global environmental problems • Disposal of secondary pollutants： • Bottom ash • Leachate • Fly ash • Flue gas Total static investment Cost O&M cost Cost-benefit analysis of WtE Figure: System framework for cost-benefit analysis

10. Calculation methods Net present value Greenhouse gas emission reduction

11. Tianjin Shuangkou Landfill Gas Recovery and Electricity Generation Project • Tianjin Binhai Municipal Solid Waste Incineration Power Generation Project

12. Result

13. Conclusions • Synergistic effect of emissions mitigation: Incineration E < Landfill E • It is because that fossil carbon can emit GHG in incineration process, such as CO2, and auxiliary fuel is needed to add, as a result of low thermal value of MSW. • Net GHG reduction cost: Incineration E > Landfill E • Incineration facilities needs high investment, long funding cycle and high operation cost. On the contrary, the technique of landfill is mature and the operator is simple, with low investment, high treatment capacity and low cost.

14. Thank you!