Landfill gas (LFG) processing via adsorption and alkanolamine absorption

Landfill gas (LFG) was upgraded to pure methane using the adsorption and absorption processes. Different toxic compounds like aromatics and chlorinated compounds were removed using granular activated carbon. The activated carbon adsorbed toxic trace components in the following order: carbon tetrachloride > toluene > chloroform > xylene > ethylbenzene > benzene > trichloroethylene ≈ tetrachloroethylene. After removing all trace components, the gas was fed to absorption apparatus for the removal of carbon dioxide (CO₂). Two alkanolamines, monoethanol amine (MEA) and diethanol amine (DEA) were used for the removal of CO₂ from LFG. The maximum CO₂ loading is obtained for 30 wt.% MEA which is around 2.9 mol L^{- 1} of absorbent solution whereas for same concentration of DEA it is around 1.66 mol L ^{- 1} of solution. 30 wt% MEA displayed a higher absorption rate of around 6.64 × 10^{- 5} mol L^{- 1} min^{- 1}. DEA displayed a higher desorption rate and a better cyclic capacity as compared to MEA. Methane obtained from this process can be further used in the natural gas network for city.