Study on optimizing evaluation and recovery efficiency for landfill gas energy collection



The distribution of the vertical wells has the significant effect on the collection capacity of methane in landfill. The gas wells spacing that contribute to the wells point should be predicted according to the field condition, such as organic fraction, density, reservoir capacity, and so on. The Multi-wells Co-optimizing Method (MWCOM) was developed for pre-accessing the collection system to increase the methane recovery efficiency. This method depend on the well spacing and well number and recovery efficiency as output variables to reach the optimum of the control of the pumping system to the gas. The application of the MWCOM was presented for vertical wells distribution in C.J.C. landfill in China. And the field measurement of gas production from running wells was investigated. The results show that the recovery efficiency can be largely increased by using the MWCOM. The recovery efficiency from field measurement was up to 74.5%–85.1% in the last two years. The method is validated by the comparison between the simulation and test results in four areas. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 972–977, 2014