Effect of Oven Drying and Reactor Temperature on Rice Husk Pyrolysis in a Fixed Bed Reactor

Abstract

This work investigated the effect of different oven drying and furnace temperatures on product yield distribution of rice husk pyrolysis. Rice husk was procured from a rice milling plant in Ogbomoso, South-Western Nigeria and was sundried for 3 days, and then oven dried at different temperatures (60, 75, 90, 105 and 120 ⁰C) for 30 minutes in Chemical Engineering Laboratory, Ladoke Akintola University of Technology, Ogbomoso, Nigeria. The samples were then pyrolysed at different reactor temperatures (400, 500, 600 and 700 °C) with a residence time of 25 minutes. The retort was inserted into the furnace after being fed with the sample. For each run, the reactor temperature was set to be 100 ^oC higher than the desired temperature in order to compensate for heat loss during retort insertion. Moisture loss was in the range 5.58% (at 60 ^oC drying temperature) to 9.03% (at 120 ^oC drying temperature). The yields of tar, gas and char were then obtained after pyrolysis and expressed in percentage of the weight of the initial sample. Tar (liquid), char and gas yields were in the range of 8-12%, 30-50% and 18-58%, respectively at different oven drying and reactor temperatures. Findings showed that char yield was largely influenced by oven drying temperatures at reactor temperature of 700 ^oC. Results also showed that the yield of liquid can be optimized at reactor temperature of 500 ^oC while that of gas at 700 ^oC. Oven drying and reactor temperature conditions strongly influenced the yield of bio-fuels from rice husk pyrolysis.