Design, Fabrication and Evaluation of Non-Continuous Inverted Downdraft Gasifier Stove Utilizing Rice husk as feedstock

Abstract

Gasification technology has been proven to be an effective conversion technology for biomass resources. Despite the existence of gasifier stoves, its utilisation and adaptation has not been extensive in Ghana mainly due to its high cost and inefficiencies. The paper presents design, fabrication and performance analysis of an inverted downdraft gasifier cookstove utilising rice husk as feedstock at laboratory level. Non-continuous inverted downdraft gasifier cookstove was designed for a family size of five with energy requirement for cooking of 5,333 kJ/hr. Laboratory test for the cookstove was performed to determine thermal efficiency and other performance parameters as well as CO, CO2 and particulate matter emissions using Water Boiling Test (WBT) version 4.2.3. The Portable Emission Monitoring System was used to conduct the WBT experiment. Inverted downdraft gasifier of height and diameter of 0.88 m and 0.22 m respectively was designed and fabricated. Evaluation of the gasifier stove revealed thermal efficiency varying between 30.5-38.1%. Emission analysis of the stove revealed low emissions compared to traditional cookstoves as well as other improved cookstove with high Power CO and PM2.5 emissions found to be 19.35 g/min/L and 932.73mg/MJd respectively. The average CO/CO2 ratio was also determined to be 0.055. The findings indicate that, the developed inverted downdraft gasifier stove is very efficient, however, the CO, CO2 and PM2.5 emissions can be improved further to meet recommended levels presented by the World Health Organization (WHO).