ENERGY PRODUCTIONS FROM SELECTED CROP RESIDUES THROUGH ANAEROBIC DIGESTION IN A FED-BATCH LABORATORY SCALE REACTOR AT MESOPHILIC TEMPERATURE (Published)
The present energy crisis has stimulated various research programmes to evaluate energy potentials of renewable energy sources. This work evaluated and compared the energy produced from anaerobic digestion of maize stalk (MS), maize cobs (MC) and rice straw (RS) by batch experiment at mesophilic temperature (37◦C). The study was carried out in a laboratory scale batch digester. The digestion bottles were fed with 9.95, 11.70 and 7.53 g, respectively, which were calculated. The digestion took place for a period of 34 days after which the gas production was noticed to be below 1% of the total gas produced till that time. The biogas yields from organic dry matter (oDM) of MS, MC and RS were found to be 357.10 l. kg-1 oDM, 514.31 l.kg-1 oDM and 324.54 l. kg-1 oDM respectively after 34 days digestion time. Methane yields (oDM) of MS, MC and RS were also found to be 222.39 l.CH4 kg-1 oDM, 298.39 l.CH4kg-1 oDM and 211.30 l.CH4kg-1 oDM respectively. The biogas/methane yields from fresh mass (FM) of MS, MC and RS were found to be 147.59 l. kg-1 FM / 91.91 l. kg-1 FM, 180.65 l. kg-1 FM / 104.81 l. CH4kg-1 FM and 177.29 l. kg-1 FM / 115.43 l. CH4kg-1 FM. The equivalent energy of MS,MC and RS were found to be 9.35, 13.47 and 8.35 MJ respectively. Also, MS, MC and RS maize stalk were found to have methane concentrations of 61.9, 58.0 and 65.1%, respectively. This study has established that among MS, MC and RS, MC has the highest biogas and methane yieldsand in turn, energy potential
Keywords: Batch experiment, Energy, biogas potential, maize cob, maize stalk, mesophilic temperature, rice straw