Design and Effect of Equivalence Ratio on Performance Characteristics of Lab Scale FBC Gasifier

Background/Objectives: Gasification was carried in a Lab scale FBC gasifier of 0.27 m diameter and 1.2 m height with superficial air velocity of 2.16 m³ per hour of controlled air. Methods/Statistical Analysis: The experiment was conducted with the saw dust as fuel, fed through rotary feeder for gasification. The gasification was initiated by feeding the fired charcoal into the reactor along with the air for partial combustion. By varying the equivalence ratio, the composition of producer gas and gas yield was recorded. The gasification temperature was maintained by sand without any other external sources of heating such as heating filaments and steam. Findings: The end product of gasification was producer gas, which is obtained by maintaining bed fluidised by supplying the optimum air in order to achieve the partial combustion. The gas was produced successfully with limited air and without external source of heat. The gas analyser is used to measure the percentage composition of producer gas and temperature is measured with thermocouple. The readings are measured by varying the equivalence ratio. The measured values are tabulated and plotted in graph for discussion. It is found that, increasing the equivalence ratio results in increase of gas yields and gasification temperature. The gasifier designed was found suitable to use in rural areas for furnace applications. Application/Improvements: Biggest challenge lies in developing the gasification system with reliable gas purification system and with power generation source for supplying air.