Performance and Economic Feasibility Assessment of a Small-scale Updraft Gasifier for Domestic Applications in South-West Nigeria

Abstract

Nigeria needs alternatives to liquefied petroleum gas (LPG), whose growing price and scarcity have led to a greater reliance on firewood and charcoal, increasing pollution and carbon footprint. To provide sustainable and affordable cooking energy, this study examines the design, performance, and economic viability of a small-scale updraft gasifier using Gliricidia Sepium feedstock for home use in South-Western Nigeria. The methodology of this study involved material selection, gasifier design and construction, experimentation, performance evaluation, and evaluation of economic viability. Investigation of the effects of temperature and feedstock size on gasifier performance revealed that higher operating temperatures increased carbon monoxide yield (from 12.2% at 306 ℃ to 20.2% at 453 ℃), improved the gas's higher heating value (HHV), and overall system efficiency. With a power output of 7.60 kW, gasifier efficiency of 81.6%, and a char yield of 10%, the gasifier demonstrated efficient operation and acceptable gas quality. Economically, the system provided about 20,000 MJ of cooking energy annually at a Levelized Cost of Cooking (LCOC) of ₦0.82 ($0.001) per MJ, which is substantially less than the ₦31.95 ($0.02) per MJ for LPG. Its high viability was confirmed by the payback period of 0.37 years and the net present value (NPV) of ₦976,447, respectively. This study is significant because it shows that domestically produced biomass gasifiers can provide a low-cost, clean, and energy-efficient domestic cooking option, particularly in areas with an abundance of agricultural waste, thereby supporting Nigeria's clean energy transition and sustainability goals. Hence, the advancement and adoption of this technology should be prioritized by the government.