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

Self Cite

The rationality of air injection well for operation parameter design is important for effective repair and safety of aeration systems in landfills. On the basis of the literature, the operating results of the air injection systems used in field sites were summarized, and the key design parameters were addressed. The operation and assessment of aeration systems were presented. First, the behavior of oxygen transport was caused by the characteristics of the pore media in the waste body. A mathematical model was needed to address the spatial–temporal evolutions of oxygen concentration in landfill. The optimum design method of gas injection well should be developed to elevate the oxygen content at maximum level across the field site, applying to most landfills. Second, an effective leachate exchange and recirculation plan should be developed to ensure sustained aerobic reaction in full scale. Some experiences of leachate discharge in field sites were presented. Third, the relationship between oxygen consumption and stability indicators should be determined to create an effective aeration plan. This function will help evaluate the reliability of aeration systems. This study provides evidence for the design, construction, operation, and effectiveness assessment of air injection well in repair engineering of landfills. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 412–419, 2017

Section: Discussionmentioning

confidence: 94%

The viability of design and operation of the air injection well for improvement In Situ repair capacity in landfill

Liu

Xue

et al. 2016

Self Cite

“…The parameters in dual‐permeability model were determined by using optimization routine [shown in Ref. ] with the data of gas flow rate from experiments. The numerical simulation program was completed by using Matlab language.…”

Section: Dual‐permeability Model Of Gas Flowmentioning

confidence: 99%

“…The capacity of the gas flow is one of the most important factors in evaluating gas emission and distribution in a landfill . The variation of the gas flow rate depends on the distribution of the permeability and pore structure within the landfill.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of dual permeability of gas flow in municipal solid waste: Experiment and modeling

Liu

Xue

Wan

et al. 2015

Self Cite

Non‐homogeneity of permeability largely depends on heterogeneity of the pore structure of waste in a landfill, which contributes to variation in gas flow state. Gas pressure dropping test (GPDT) was one of the most effective methods to describe the gas preferential flow, was used to investigate the gas breakthrough curves in initial pressures, moisture contents and degradation phases in lab test. Dual‐permeability model was developed to quantify the gas preferential flow in waste column. The reliability of the model was verified by a good agreement from the gas flow rate between the simulation results and experimental results. The simulation results show the biodegradation of the waste produced an obviously decrease in the permeability in fracture system due to the variation of the particle distribution. The porosity and mass transfer in fracture system has largely decreased with the continued biodegradation and moisture content increasing. It will be provided useful evidence for assessing the gas preferential flow during the well operation in landfill. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 41–47, 2016

“…Gas collection systems have been widely used in LFG collection as a traditional method . The method is to apply pumping negative pressure to the arranged gas well . Cover properties, anisotropy ratio and pumping well depth, and so on would affect the migration of LFG .…”

Section: Introductionmentioning

confidence: 99%

Study on landfill gas migration in landfilled municipal solid waste based on gas–solid coupling model

Zeng

2019

Gas migration rule is of great significance to the safe disposal of landfill. In this article, a gas–solid coupling model was developed and used to simulate the effects of various factors on gas migration. The simulation results showed that gas pressure in landfill decreased with the increase of extraction pressure, anisotropy ratio, coverage gas permeability, extraction well depth, and coverage thickness. The maximum value of gas pressure could reach 683 Pa. Among these factors, extraction pressure played the largest role in the gas pressure, while coverage thickness played the smallest role in it. The radius of influence (RoI) and gas flow rate increased with the increase of extraction pressure, refuse gas permeability, coverage thickness, and the extraction well depth, but with the decrease of coverage gas permeability. The effect of extraction well depth on RoI and gas flow rate was the most significant. When extraction well depth increased from 0.5 landfill height to 0.9 landfill height, the maximum values of RoI and extraction volume increased by 20 m and 20 m3/hr, respectively. It was suggested that the design of landfill gas (LFG) collection system should consider the influence of various factors in practical engineering.