Quantification of parameters influencing methane generation due to biodegradation of municipal solid waste in landfills and laboratory experiments

Abstract

The energy conversion potential of municipal solid waste (MSW) disposed of in landfills remains largely untapped because of the slow and variable rate of biogas generation, delayed and inefficient biogas collection, leakage of biogas, and landfill practices and infrastructure that are not geared toward energy recovery. A database consisting of methane (CH4) generation data, the major constituent of biogas, from 49 laboratory experiments and field monitoring data from 57 landfills was developed. Three CH4 generation parameters, i.e., waste decay rate (k), CH4 generation potential (L0), and time until maximum CH4 generation rate (tmax), were calculated for each dataset using U.S. EPA's Landfill Gas Emission Model (LandGEM). Factors influencing the derived parameters in laboratory experiments and landfills were investigated using multi-linear regression analysis. Total weight of waste (W) was correlated with biodegradation conditions through a ranked classification scheme. k increased with increasing percentage of readily biodegradable waste (Br0 (%)) and waste temperature, and reduced with increasing W, an indicator of less favorable biodegradation conditions. The values of k obtained in the laboratory were commonly significantly higher than those in landfills and those recommended by LandGEM. The mean value of L0 was 98 and 88L CH4/kg waste for laboratory and field studies, respectively, but was significantly affected by waste composition with ranges from 10 to 300L CH4/kg. tmax increased with increasing percentage of biodegradable waste (B0) and W. The values of tmax in landfills were higher than those in laboratory experiments or those based on LandGEM's recommended parameters. Enhancing biodegradation conditions in landfill cells has a greater impact on improving k and tmax than increasing B0. Optimizing the B0 and Br0 values of landfilled waste increases L0 and reduces tmax.

Translating landfill methane generation parameters among first-order decay models

“…Here, both L 0 and k have been determined by waste composition to compare results of single-phase and multiphase models. Calculating k based solely on waste composition, similar to the calculation of DOC or L 0 , implies that L 0 and k are directly related (Fei et al, 2015). However, research attempting to fit estimated gas generation to modeled results has shown that L 0 and k are inversely related (Tolaymat et al, 2010).…”

Avaliação dos parâmetros cinéticos da geração de metano em uma célula experimental de resíduos sólidos

“…Normalmente, estes modelos dividem os resíduos sólidos urbanos (RSU) em várias categorias, cada uma com seu respectivo potencial de geração de metano (L) a partir da biodegradação de RSU e constante de biodegradação (k) (MACHADO et al, 2009;MOU;KJELDSEN, 2015;FEI;ZEKKOS;RASKIN, 2016 et al, 2009;MACIEL & JUCÁ, 2011;SCHEUTZ et al, 2011;ABREU, 2014;MOREIRA & CANDIANI, 2016 ). T(t' ,t) pode ser chamada de função resposta do aterro sanitário quanto à produção de metano, já que fornece a taxa de geração ao longo do tempo causada por uma deposição unitária de RSU.…”

Comparative Analysis of Biogas Estimation Models versus <i>In-Situ</i> Measurement in a Landfill Site in the State of Mexico, Mexico

“…This model requires data related to the average annual rate of waste disposed, the number of years the landfill has been or was open, the number of years that the landfill has been closed, the potential of waste disposed to generate methane and the rate of methane generation of the waste disposed [16]. The estimate of methane generated by the first order equation is expressed as follows [17]:…”