Ecology, Environment and Conservation Paper

APPLICATION OF ALKALINE CHEMICALS FOR BIOGAS METHANE ENRICHMENT

Fayaz A. Malla, Shakeel A. Khan and Navindu Gupta

Abstract

Biogas, an environment friendly renewable fuel is generally produced by anaerobic digestion of organic waste and has huge prospective for growth to meet our future energy demands. However, there are two major concerns related to the biogas namely (1) making biogas transportable and (2) increasing biogas calorific value. This can be achieved only after removing its carbon dioxide and H2S. In this paper the results of pilot level trials to absorb CO2 from biogas with the diverse solvents has been explored. In the present study the asserts on the performance of different solvents (aqueous solutions of NaOH, KOH, Ca(OH)2, mono ethanol amine (MEA), Polyethylene glycol (PEG), NH4OH and EDTA) very closely. Test results divulged that these solvents were efficient in responding with carbon dioxide in biogas (up to 94% elimination efficiency), the end result in CH4 enriched biogas. Resuts revealed that the total amounts of carbon dioxide absorbed were in the range between 0.065 and 0.36 kg/kg, with the highest absorption in Ca (OH)2 solution. The absorption potential was transitory in nature and saturation obtained at 6 min for PEG, and 12 min for all other solvents. We could reuse these solvents for upgrading CH4 enriched biogas. Hence, this technique proved to show potential in improving the calorific value of biogas. Loading capacity of NH4OH, NaOH and MEA were almost same. Thus, this modus operandi validated the capability of upgrading the biogas prominence.