Rice straw & husk as potential sources for mini-grid rural electricity in Nigeria

Mini-grid based renewable biomass energy to augment rural electrification in Nigeria can play an important role in the transition process from the present country's fossil fuel based energy supply to a renewable fuel-based economy. Rice is a widely grown staple crop in Nigeria and the straw and husk generated as by-products of rice harvesting and processing, respectively are important energy sources. The focus of this paper was to assess the quantity of rice straw and husk produced, estimate greenhouse gas (GHG) emissions based on open field burning, and assess its possible energy potential for mini-grid electric power generation and related GHG emissions mitigation potential in Nigeria.

Ten year average statistics on rice production in Nigeria were used in this study in combination with the literature values on straw-to-grain Ratio (SGR) and husk-to-grain ratio (HGR) to quantify the amount of rice straw and husk produced respectively. It was estimated that the amount of rice straw and rice husk that 2.2 million t yr⁻¹ and 0.7 million t yr⁻¹ may be available as a feedstock in Nigeria, respectively. It was illustrated that 1.3 million MWh yr⁻¹ and 0.4 million MWh yr⁻¹ of electricity can be accessed from rice straw and rice husk, respectively. Furthermore, the mitigated GHG emissions when generated electricity from rice straw and rice husk is used would be 5.8 million t CO2-equiv. yr⁻¹.