Pretreatment of coconut Husk for biogas Production by anaerobic fermentation with cow dung

Abstract

The optimal pretreatment condition of coconut husk by physicochemical methods for biogas production was investigated. The coconut husk was dried and ground into powder (~0.1 nm) and was then determined for chemical contents such as cellulose, hemi-cellulose and lignin, respectively. The chemical contents of cellulose, hemi-cellulose and lignin were 35.67±2.02, 7.41±0.69 and 40.82±0.62 w/w, respectively. After pretreatment with 4 different methods, the results showed that the pretreatment of sodium hydroxide 30 % (w/w) gave the highest chemical contents of cellulose, hemi-cellulose and lignin with 43.30±0.03, 33.69±7.48 and 27.36±0.03 w/w, respectively. As for the biogas production, the result showed that the ratio of coconut husk to cow dung of 1:4 with C:N ratio of 23:1 gave the highest cumulative biogas of 442.6 ml for 30 days. Methane and carbon dioxide contents were 46.1 and 23.1 %. Moreover, the removal percentages of the total solids (TS), volatile solid (VS), suspended solids (SS) and COD were 69.3, 32.5, 50.0 and 58.4 %, respectively. The coconut husk could be used as an alternative material for the application of biogas production with cow dung in the near future.