Performance Analysis and on-Site Investigation of Fixed Bed Gasifier

Abstract

India is facing a major problem of rural electrification nowadays. It is because of the expensive and sometime non-feasible grid connection in the interior parts of India. In such areas, it is required to develop a reliable and sustainable energy source for rural electrification. To overcome this problem, the researchers from all around the world focus to find out potential solutions. A standalone gasifier coupled with I.C. Engine has proven its potential to face this surge in fulfilling the energy requirement of the rural electrification. The purpose of this study is to estimate the potential of gasification process as an alternative to the combustion of bio-waste and municipal solid waste (MSW). Different gasifiers at Gujarat, Rajasthan, Punjab, and Uttarakhand had been surveyed for techno-commercial applications and their performance parameters were recorded. The experiments were conducted on 20 kWe downdraft gasifier at National Innovation Foundation (Grambharti, Gandhinagar). After necessary troubleshoot and maintenance of the gasification system, experiments were conducted with different types of wood (babul, teak, and neam) pieces. Performance parameters such as the surface temperature of the gasifier reactor, air flow rate, gas flow rate, engine output voltage, Engine oil pressure, etc were recorded. Air flow rate, engine output were found in the range of 0.696 m3 min-1 to 2.046 m3 min-1 and 390 V to 400 V, respectively whereas engine oil pressure remained at 3.9 kg cm-2 for different wood feedstock. It was observed that the oxidation zone of the gasifier system was chocked while long-run experimentation. To overcome this problem, a screw conveyor was attached in the oxidation zone of a gasifier reactor. Experiments were repeated with different feedstock and air flow rate, engine output, and engine oil pressure were found in the range of 0.150 m3 min-1 to 2.560 m3 min-1, 410 V to 420 V and, 2 to 3 kg cm-2 respectively. After satisfactory run the gasifier on bio-waste, a gasification system was modified for MSW (called refused derived fuel (RDF)). Co-gasification were carried out with RDF and wood (50:50, wt%) and found air flow rate, engine output in the range of 0.249 m3 min-1 to 0.491 m3 min-1 and 425 V to 450 V, respectively whereas engine oil pressure remained at 3 kg cm-2. Experimentation with 100% MSW was intentionally avoided due to the fact that MSW may produce higher tar and smoke products which can damage the engine. MSW can be used to generate electricity by gasification route is the major conclusion from the present study.