Investigation of Tar and PM from Producer Gas in Downdraft Gasifier

Abstract

In India, ample amount of biomass is generated. Thermal and electric power generation through biomass is estimated 25 GW per year in India. Globally, various technologies are available for conversion of biomass such as thermochemical conversion and biochemical conversion. Gasification is thermochemical conversion and which is one of the key option for off grid rural electrification. In gasification, biomass is converted in to producer gas, which has medium calorific value gas. This gas is rich in H2 and CO. However, this technology is century old, but it is not fully developed especially for electricity generation because of it contaminant such as Tar and Particulate matter (PM). Tar is condensable at the downstream of gasifier system which leads clogging or blockage in the process equipment. PM can create problems like fouling, corrosion etc. A 10 kWe downdraft gasifier was developed with the support of Department of Science and Technology (DST), Government of India. Four feedstocks (wood, cumin + saw dust briquette, saw dust briquette, lignite + wood)) were identified for the experimentation. This study represents the results of experimental investigations on content of Tar and PM in producer gas, Gas generation rate, gasifier efficiency, Tar and PM. Measuring device was developed as per Guide-lines of Ministry of New and Renewable Energy Source (MNRE). It was observed that higher Tar and PM is found with 25% wood + 75% lignite as feedstock which is 2.904 gm/m3 and 0.1567764 gm/m3 respectively. Wood is preferred among all four feedstock as per least Tar (0.564 gm/m3) and PM (0.016 gm/m3) content and maximum efficiency (74.80%).