Bioenergy from Rice Husk in Ebonyi State: Assessing Resource Availability and Conversion Options

Ebonyi State in South East Nigeria is a significant rice-producing region, generating large quantities of rice husk as a milling by-product that is currently disposed of through open burning, contributing to air pollution and greenhouse gas emissions while squandering a valuable bioenergy feedstock. This study assesses the availability of rice husk as a bioenergy resource in Ebonyi State and evaluates technically appropriate conversion options for electricity and heat generation. Milling industry surveys were conducted across 23 rice mills in Abakaliki and Ohaukwu local government areas to quantify annual husk output, moisture content, and current disposal practices. The energy content of husk samples was determined through proximate analysis and bomb calorimetry. Three conversion technologies, including combustion-based power generation, gasification, and densification into husk briquettes, were evaluated against criteria of local technical capacity, investment cost, and scalability. A feasibility model for a 200-kilowatt rice husk gasifier power plant co-located with an Abakaliki rice mill cluster is developed, with capital cost and revenue projections over a fifteen-year period. Results indicate positive financial returns at a discount rate of 12 percent, with electricity costs of 42 naira per kilowatt-hour, substantially below local diesel generation costs. The study recommends a co-operative energy development model linking rice miller associations with the Ebonyi State Rural Electrification Agency. Keywords: rice husk, bioenergy, Ebonyi State, gasification, agricultural residue energy.