Gasification of Maize Cobs and its Characterization for Energy Generation

Abstract

gasification of maize cobs and its characterization for its energy potential was carried out. The proximate analysis of the maize cob gave 17.5% moisture content, 1.5% ash content, 73.0% volatile matter, and 8.0% fixed carbon content. A high calculated calorific value of 14.71 MJ/kg was gotten. The exit gas from pyrolysis at 5500C consists of CO, CO2, H2, H2O, CH4, N2, and C2H6 with percentage composition 7.3%, 11.49%, 0.52%, 4.7%, 4.18%, 3.66%, and, 7.83% respectively. At 700 ⁰C, the compositions were found to be 8.4%, 13.2%, 0.6%, 5.4%, 4.8%, 4.2%, and 9.0% respectively while 9.49%, 14.91%, 0.68%, 6.1%, 5.42%, 4.74% and 10.17% respectively was obtained for pyrolysis 850⁰C. The gasification process revealed that as the temperature was increased more of the biomass was converted to gas leading to less char generation. The result also showed increase in hydrogen, methane, carbon monoxide as well as less desirable carbon dioxide with increase in pyrolysis temperature. The elemental analysis for percentage of carbon, hydrogen, oxygen, nitrogen and sulfur emitted during gasification at 700 ⁰C for 15 minutes revealed C-78.43%, H-0.64%, O-19.98%, N-0.66%, and S-0.29%. The low amount of sulfur and nitrogen emitted concludes that maize cob can be tapped as a source for energy application. Optimization can be carried out to determine the optimal temperature for high calorific value gas yield