Performance evaluation of a Retrofitted Cook Stove by co firing Biomass with steam, spirit and Bio-diesel

Abstract

The continued use of biomass cookstoves in households and the traditional open fires for cooking is not only a major health hazard but also an environmental hazard. Although biomass offers a sustainable and carbon neutral source of energy, its inefficient use in household cooking has led to the indoor air pollution due to smoke emission resulting to respiratory and other health problems. The main objective of this study was to determine the performance of a retrofitted cook stove co-firing biomass with steam, spirit and bio-diesel. The specific objectives were to design and fabricate a retrofitted cookstove, determine the thermal efficiency of biomass when steam, biodiesel and spirit are used as gasification agent and to carry out the techno-economic analysis of the retrofitted cookstove. Mild steel, copper and aluminium were selected as the construction material. The computer aided drawing (CAD) was used to design the cook stove based on cook stove energy requirements, reactor diameter, height of the reactor and the heat exchange area for the gasification agent (steam). The fabrication was guided by technical 2D and 3D CAD drawings. The empirical relations for the design were borrowed from closely related literature, such as energy requirements, fuel consumption rate, reactor diameter, height of the reactor and heat exchanger for steam. The performance was based on already established standard methods which includes efficiency, fire power and burning rate. The analysis revealed an efficiency of retrofitted stove when biodiesel, spirit and water were used was 53.83%, 37.65% and 14.75% respectively. The fire power for retrofitted stove for water, spirit and biodiesel were 76.66 J/s, 80.93J/s and 83.93J/s respectively. The burning rate for retrofitted stove for water, spirit and biodiesel were 0.25g/sec, 0.27g/sec and 0.28g/sec respectively. The boiling cost in KES for 1 liter of water in Retrofitted stove, Envirofit, Jiko Koa, Clay stove, and Kenya ceramic jiko were 2.0,20.0,23.9,31.1 and 31.6 respectively. The initial cost in KES for acquiring Retrofitted stove, Envirofit, Jiko koa, Kenya ceramic jiko and Clay stove were 4,895, 5,470, 5,499, 500 and 2,500 respectively. The Power for Envirofit, Jiko koa, Kenya ceramic jiko, Clay stove and Traditional stove were 0.95J/s,0.71J/s,0.37J/s,0.36J/s and 0.35J/s respectively. In conclusion retrofitted cook stove was more efficient and emits limited smoke when cooking hence friendly to the environment and improve rate of cooking. Further studies be done on rate and amount of gas produced as syngas from retrofitted cook stove