Powder Technology, Vol.323, 588-593, 2018
Production and separation of rice husk pyrolysis bio-oils from a fractional distillation column connected fluidized bed reactor
Rice husks are pyrolyzed in a fluidized bed pyrolyzer and the produced vaporized bio-oils are immediately separated by fractional distillation. The effects of the pyrolysis temperature, rice husk feeding rate and superficial gas velocity on the distributions of chars, bio-oils and syngases in the product are studied. When the pyrolysis temperature is 500 degrees C, the rice husk feeding rate is 20 g/min and the superficial gas velocity is 0340 m/s, the mass fraction of bio-oil in the product shows the highest value of 30.4%. The decomposable volatiles in the chars are the lowest for the chars obtained at the lower rice husk feeding rate of 10 g/min and higher superficial gas velocity of 0.425 m/s. GC-MS analyses indicate that the major chemicals in the bio-oils are acetic acid, furfural, phenol and phenol derivatives. The fractional distillation separates the bio-oil into a light fraction (C4-C7) and a heavy fraction (C7-C10). Relatively high content of acetic acid in the light fraction of the bio-oil is responsible to the lower pH value of the light fraction of the bio-oil. Phenolic compounds are rich in the heavy fraction. Vaporized bio-oils directly from the fluidized bed pyrolyzer are successfully graded by fractional distillation. (C) 2016 Elsevier B.V. All rights reserved.