Analysis of the Influence of Permeability and Structure for Enhancing the Extraction Efficiency of Landfill Gas

 

Xu Yue

Institute of Civil Engineering and transportation , Liaoning Technical University , Fuxin, Liaoning, 123000; e-mail: xy_cersm@163.com

Yi Fu

Institute of Civil Engineering and transportation , Liaoning Technical University , Fuxin, Liaoning, 123000; e-mail: yifu9716@163.com

Liu Lei

State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences, Wuhan, Hubei 430071, P.R.China; e-mail: lliu@whrsm.ac.cn

Tian Yu

Wuhan Environmental Sanitation Science Research Institute, Wuhan, 430015, China; e-mail:tianyuxuwen@126.com

 

 ABSTRACT

The structure and the permeability of each layer in landfill have a significantly influence on the emission and distribution of the landfill gas. A two-dimensional (2D) dynamic model for assessing the gas extraction was developed. The comparison of within high-permeability layer and without high-permeability layer near the top surface of the landfill across the gas collection was presented. The numerical simulation results show that the collection rate of gas extraction well can be improved effectively with high-permeability layer and it can also reduce the gas emission into atmosphere. Gas collection rate is increased with the increasing of the permeability of refuse. There were larger porous volume and gas flow channel in high-permeability layer, which accelerate the gas flow into wells. As the increasing of the ratio of horizontal to vertical permeability, the lateral flow velocity of landfill gas (LFG) was enhanced by a larger range, leading to a highly increase of LFG extraction efficiency. There is an important significance for design of extraction system optimization and methane renewable.

Keywords: landfill gas, high-permeability layer, migration, gas collection rate

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