Performance Evaluation Of Downdraft Gasifier For Syngas Production Using Rice Husk
Abstract
Biomass gasification is a thermochemical process that converts biomass to a combination of feasts known as syngas comprising substantially of CO, H2and CH4 as a result of partial combustion with a gasifying agent. It’s considered to be a promising clean energy option for reduction of hothouse gas emigrations and a way of exercising agrarian wastes like rice cocoon. The syngas can be used not only to produce heat and power but in conflation of liquid energies and chemicals. This exploration comprises of rice cocoon characterization, fine model expression to prognosticate rice cocoon gasification theoretically and gasification of rice cocoon using both air and oxygen- amended air as gasifying agents experimentally. Theoretical rice cocoon air gasification was done by inputting the composition of the characterizedrice cocoon into set of fine equations deduced grounded on thermodynamics, mass and energy balances using equilibrium approach and performing equationswere reckoned using MATLAB as a toolto predictsyngas composition and spicy value between temperature of 500 and 1100 °C. Experimental ricehusk gasification was conducted using a downtrend gasification system installed at National Research Institute for Chemical Technology, Zaria, Nigeria, comprising of a gasifier as reactor, cyclone, sludge and air cracker . The gasification was done with two different gasifying agents; air and oxygen- amended air. For the air gasification, effect of6.4,3.0 and0.7 L/ min inflow rates were studied while for the oxygen- amended air gasification, 30 to 100 oxygen enrichment in air were examined. Temperature, syngas composition and spicy value were covered during the trial using online movable infrared syngas analyser( Gasboard 3100P series), digital thermometer( UT 350) and K- type( chromel- alumel) thermocouple. The results of the model indicated an optimum temperature at 800 °C with syngas composition of18.72 CO,16.68 H2,13.05 CO2, and0.39 CH4, and4.47 MJ/ m3 spicy value. The stylish experimentalsyngas composition was at6.4 L/ min air inflow rate with composition of10.83 CO,9.51 CO2,2.12 H2 and1.18 CH4, asked syngas composition of14.13 and parity rate of0.128, with an average temperature of 567 °C and2.53 MJ/ Nm3 spicyvalue.Root mean square error value of7.58 was calculated when the model developed was validated with the stylish results attained from rice cocoon air gasification. For oxygen amended- air rice cocoon gasification, the stylish point was considered at 50 oxygen enrichment in air having the loftiest CO to CO2ratio of1.63 with parity rate of0.494, asked syngas of24.34, syngas composition of19.8 CO,12.16 CO2,2.26 H2,2.28 CH4, and spicy value of3.67 MJ/m3.Performance analysis shows that for air gasification the loftiest Carbon
Conversion effectiveness( CCE) and Cold Gas Efficiency( CGE) was achieved at the loftiest air inflow rate(6.4 L/ min) as21.27 and12.55respectively.While for oxygen-
fortified air gasification, 50 oxygen enrichment in air gave the stylish values of both CCE and CGE as46.72 and26.24, independently.
Chapter One
Preface
Background of the Study
Access to cheap, dependable, and sustainable energy is a precursor for attaining and sustaining socio profitable development. In fact it’s abecedarian demand for poverty reduction. presently about 90 of the world primary energy consumption is from reactionary( petroleum, gas and coal),(Melgaraetal., 2009). still depleting of these reactionary energy sources, the rate at which carbon dioxide( CO2) is released into the atmosphere when they’re burnt and adding demand of the world energy due to population coupled with technological advancement are the current challenges. These challenges have served as provocation encyclopedically to develop indispensable and renewable energy like biomass and solar that can help the present generation to meet their energy demand without risking the capability of the unborn generation to meet their energy demand.
Biomass is anon-fossilized and biodegradable organic material forming from shops, creatures andmicro-organisms. They include products, by- products, remainders and waste from husbandry, forestry and related diligence as well as thenon-fossilized and biodegradable organic fragments of artificial and external wastes. Biomass has high but variable humidity content and is made up of carbon, hydrogen, oxygen, nitrogen, sulphur and inorganic rudiments( Bhavanam and Sastry, 2011). The biomass is the only source of carbon- grounded renewable energy(Pandeyetal., 2013) and the most dominant renewable energy source used in the world moment, comprising nearly 80 per cent of the total force.