DESIGN OF BIOMASS POWER PLANT FOR ELECTRICAL GENERATION AT SELECTED SAWMILL INDUSTRIES IN AKURE, ONDO STATE, NIGERIA

Abstract

Biomass (wood wastes) fired power plant that could substitute fossil derived fuel in running the operations of three selected sawmill industries in Akure, Ondo state, Nigeria had been designed. The industries and their geographical coordinates are; Oyo sawmill (7.2926°, 5.1604°), Chika sawmill (7.2556°, 5.1497°) and Iya Eji sawmill (7.2336°, 5.2367°). Incessant national power outages and unpredictable voltage fluctuations could be held accountable for the decision by the owners of the sawmills to keep the facilities running on diesel fuel (since inception, and through a period that spanned over 25 years), hence, incurring huge financial expenses. A need therefore arises to develop an alternative power plant that could utilise the wood wastes generated by the mills for energy. A waste to energy (WTE) power plant is hereby designed to lower the general overhead of the mills to its minimum since the fuel used would be free, available and renewable. Ten wood species were identified at each of the mills and the wastes generated ranges from 388 kg/day in Oyo, 872 kg/day for Chika and 488 for Iya Eji sawmills. The ultimate and proximate analysis of the wood wastes from the selected mills were experimentally determined and a model that could predict the heating value of wood wastes from any other wood species was also developed. The electrical power requirement for running the various mills was determined through energy audit of the total installed plant capacity at the mills. Oyo sawmill requires 36.24 kW, Chika sawmill requires 76.5 kW while Iya Eji sawmill requires 41.16 kW. The designed WTE plant that runs only on the wood waste generated by sawmills would generate 60 kW for Oyo, 136 kW for Chika and 70 kW for Iya Eji sawmills. The capacity for the components of wood waste fired plant were also determined; boiler power for Oyo, Chika and Iya Eji sawmills were 235 kW, 531 kW and 274 kW respectively, the turbine power were 88.89 kW, 201.48 kW and 103.7 kW while the condenser power were 146 kW, 330 kW and 170 kW respectively. Regression model that could predict the plant capacity for any other sawmill was also developed. The WTE plant will relieve dependency on the non-renewable energy fuel, lower the overhead expenses of the industries, convert waste to wealth and provide a cleaner environment by consuming wastes to generate power.