DEVELOPMENT OF A BIOMASS PYROLYSER FOR SAWDUST AND RICE HUSKS CONVERSION TO ENERGY

Abstract

Renewable energy sources are climatic condition dependent. Likewise, bio-digester does not produce biogas instantly. Against these backdrops, a biomass pyrolyser was designed, fabricated, and evaluated. The machine comprised of a reactor, furnace, and a moisture removal cylinder. The pyrolytic gas was produced by thermal decomposition of biomass waste in the reactor. The pyrolyser was evaluated using a 2 x 5 x 5 factorial experiment in a Completely Randomized Design (CRD) with feedstock, moisture content and retention time of feedstock in the reactor as factors. Measured parameters during evaluation were total gas yield, rate of gas yield and reactor conversion efficiency. The data obtained were analyzed statistically with Statistical Package for Social Science (SPSS) 20 software. At a moisture content of 12 % dry basis, the proportion of methane (CH4) in the pyrolytic gas obtained from sawdust and rice husks were 57.3 % and 54.3 %, respectively. It was observed that the total gas yield, rate of gas yield and reactor conversion efficiency decreased as the moisture content of the biomass material (sawdust and rice husks) increased. However, as the retention time increased, all the measured parameters increased. After a retention time of 100 minutes, 2 kg of sawdust produced 1146 g of pyrolytic gas at the rate of 0.191 g/sec and 57.3 % reactor conversion efficiency. While 2 kg of rice husks produced 1124 g of pyrolytic gas at the rate of 0.187 g/sec and 56.2% reactor conversion efficiency. In less than 2 hours, a biomass pyrolyser produced fuel for operations. Therefore, it is a quick, simple and cheap method of converting biomass wastes into useful gas and it is not climatic condition dependent.