Life cycle assessment of municipal waste management in China: Analysis of operation of Yuhuan Municipal Solids Processing Facility
Slav Hermanowicz1,2, Yihao Xiang1, Siqing Xia2
1University of California, Berkeley – TBSI, United States of America; 2College of Environmental Science and Engineering, Tongji University
Life cycle analysis (LCA) was used to assess a municipal solid waste incineration facility in Yuhuan, China using an “incremental” system, whereby only operation in the analysis. The incremental approach is relevant when the goal is to assess the environmental impacts of existing facilities. A detailed inventory of material and energy inputs to the plant was developed and public health, environmental and resource impacts were assessed.
Waste is delivered by trucks over an average distance of 12.5 km. In the facility, the waste is incinerated to produce steam and electricity. Liquid leachate is processed in a treatment train using advanced membrane technology (170 L of leachate per 1 ton of waste). On average, 338 kWh of electricity is generated from 1 ton of waste while the facility itself uses 51.2 kWh of electrical energy (15% of electricity produced). The majority of energy (94%) is consumed in the incineration process and only 6% is used for wastewater treatment. Air supply fans and chimney draft fans are the major electricity-consuming units followed by boiler pump and the turbine circulating pump.
Operation impacts were evaluated in 11 mid-point categories. In each category, major benefits were obtained from electricity generation replacing other sources of electricity and from avoided disposal of waste to landfills. Negative effects were associated with waste collection by trucks with major negative impacts related to ozone layer and respiratory organics.
In further analysis, the mid-point impacts were combined into a single score of eco-points based on emissions and impacts of an “average” European in 1990 according to the well-accepted Eco-indicator 99 methodology. Overall, the operation of the facility produces net benefits of -51.3 Pts per 1 ton of waste. Major benefits (approx. -42.6 Pts) are derived from avoided landfilling and from avoided electricity generation (-11.9 Pts) from energy mix in China.