Methane Generation and Capture of U.S.Landfills

Analysis of the U.S.EPA(Environmental Protection Agency)database of 2,549 MSW(Municipal Solid Waste)landfills showed that there were 1,164 operating landfills in which 348 million short tons(316 million metric tons)of waste were landfilled in 2017.In total,these landfills occupy about 370 million square meters of land so it is not possible to monitor the generation of LFG(Landfill Gas)generation accurately,or collect most of the LFG generated.This study was based on the hypothesis that,on the average,methane generation is proportional to the tonnage of wastes landfilled annually.The Landfill Methane Outreach Program of the EPA(EPA-LMOP)compiles annual operating data of all methane-capturing landfills.Our analysis of the 2018 data for 396 LMOP operating landfills showed that 210 million short tons of wastes were deposited and 5.06 million short tons of methane were captured,i.e.,an average capture of 0.024-ton CH4/ton waste.On the basis of the anaerobic reaction of the DOC(Degradable Organic Carbon)in landfilled wastes,the average rate of methane generation from all operating U.S.landfills was estimated to be 0.05 ton of CH4 per ton of annual capacity;this number corresponds to bioreaction of about one half of the total organic carbon in MSW.On this basis,the average rate of CH4 emission from the 396 LMOP landfills was estimated to be 0.026-ton CH4 per annual ton of deposition and the average efficiency of LFG capture,48%.Adding up all 1,164 operating landfills,their total emission of methane was estimated at 11.9 million metric tons of CH4.At CH4/CO2 equivalence of 25,this number corresponds to CO2-eq emissions of 270 million metric tons,i.e.,5.1%of the U.S.energy related carbon dioxide emissions.

Energy recovery from solid wastes in China and a Green-BRI mechanism for advancing sustainable waste management of the global South

The only proven alternative for the recovery of value from materials that cannot be recycled is waste to energy(WTE).The first part of the paper provides evidence as to the advantages of WTE over landfilling and examines the role of WTE in the urban environment.The second part of the paper is a holistic analysis of the legislative instruments used in China,that have led to the construction of nearly 400 plants from 2005 to 2019.The Chinese government was instrumental in the development of Public and Private Partnerships(PPPs),in form of Build-Operate-Transfer(BOT),or Build-Own-Operate(BOO)models with a lifetime of 20 years to 30 years.The government accepts most of the investment risk by participating in the equity structure,providing strong tax and policy incentives,and becoming fully engaged in public education and acceptance of new WTE projects.The construction and operation of these plants by the private sector had to comply with the governmental performance standards in order to receive incentives,such as an appreciable credit over the price of electricity received by coal-fired plants.The last part of this paper examines how the elements of the Chinese renewable energy and waste management laws,may be transposed to federal and state legislation for potential application in countries of the Belt and Road Initiative(BRI)region.