Development of An Air-Stage Downdraft Gasifier and Performance Evaluation on Feedstock of Rice Husk

Abstract

Due to depletion of conventional fuel and increasing global warming, biomass wastes have been explored and investigated by many researchers worldwide. A biomass gasification power plant is a promising conversion technology for energy sustainability. From many existing gasifiers have been developed, mostly they have high technology, large capacity, and very costly, thus unsuitable for remote area di Indonesia. The present work aims to build a simple and low cost double air-stage downdraft gasifier for a small-scale biomass power plant system. The gasifier is tested on rice husk at equivalence ratio of 0.20, 0.30, and 0.40. The parameters evaluated are axial temperature, fuel consumption rate, heating rate, thermal efficiency, and tar content. The results show that the highest gasification temperature, fuel consumption rate, heating rate, and thermal efficiency are occurs at equivalence ratio of 0.4. The values are 904.5°C, 4.14 kg/h, 25.38 kJ/h, and 63.18%, respectively. The significant findings is that the gasifier generates producer gas with low tar content, i.e. 23.9 mg/m3 at equivalence ratio of 0.4 and the producer gas is successfully used to run the 3 kW generator set. For sustainability operation of the power plant, it is important to test the gasifier on various biomass waste feedstocks.