Study On The Application Of Rapid Collection System Of LFG In Shanghai Laogang MSW Landfill

Regarding the facts that landfill gas is not only one of the important greenhouse gases, but also the clean renewable energy, to control and use of landfill gas has become increasingly important research issue in field of landfill disposal technology. For landfill gas control, the fast and efficient gas collection before gas disposal is a critical part. In China, as generation rate of the landfill gas is fast and characterized by reaching peak rapidly and then decline quickly, the landfill gas collection way need to be adapt to this character.Laogang municipal solid waste landfill in Shanghai is a typical tidal flats type located in a low-lying terrain. With a shallow landfill depth, conditions for generation and collection of landfill gas in Laogang municipal solid waste landfill are ineffective. Therefore, with Laogang municipal solid waste landfill as study case, in order to improve its efficiencies of gas generation and collection, to design a gas collection system program according to its actual conditions through optimizing landfill partitions and gas collection methods is essential.In this study, the contents are divided into four parts. First, through comparing the gas generation model recommended by IPCC to Marticorena dynamic model, the latter is chosen here to predict quantity of the generated gas, and calculation parameters are determined. Second, in order to reduce the ratio of gas loss, the unreasonable landfill partition is optimized and a multi-partition landfill and gas collection program is proposed. Third, lateral horizontal gas extraction method is applied and the detailed program for whole landfill zone is designed, which can be served as a demonstration designing for other similar project. Fourth, with the designed experimental program for gas extraction, gas extraction experiment is conducted and the results data is used for assessment of collection rate.Based on the study results, the major conclusions are shown as below.(1) For first-stage project of Laogang municipal solid waste landfill during year of 2012 to 2039, the predicted quantity of generated landfill gas in 2012 and 2039 are 2860.28×104 and 1373.11×104 m~3/a, respectively. In 2027, the generated gas amount reach a peak with quantity of 15135.99×104 m~3/a. The total amount of generated gas during 26 years is 246265.07×104 m~3.(2) Divided into 18 separated zone for landfill area and extracting gas instantly after landfill work and closure engineering are finished, the landfill gas loss ratio is calculated with 24.6%.(3) Through multi-partition and short-time landfill method coupling with lateral horizontal gas extraction, landfill gas collection rate can reach a level higher than 60%.(4) Under same gas extraction conditions, gas collection rate of lateral horizontal gas extraction method is high and the quality of landfill gas is good.