Application of Gamma Radiation on Bio-oil Produced from Pyrolysis of Soybean Cake

Soybean cake residue from soy milk making can be pyrolysed to produce pyrolysis liquid or bio-oil which has potency to be used as liquid fuel. Pyrolysis of soybean cake residue with the application of gamma irradiation was investigated in a batch reactor at 450°C for 1.5 hr under nitrogen flow 250 cc/min. Feed of soybean cake residue was exposed to gamma radiation at the doses of 200 to 1,000 kGy before pyrolysing. It was found that pyrolysis liquid yield increased significantly by 12.9 to 19.3 % at the irradiation doses of 400 kGy and higher. The increment was mainly due to the increasing of aqueous phase in the pyrolysis liquid. The heating value of organic phase in the pyrolysis liquid was 7,890 kcal/kg. The organic phase from the unexposed feed was also irradiated at 20-100 kGy. The viscosity of irradiated organic phase was found to increase with the increasing irradiation dose. Irradiated organic phase was distilled at temperatures 200 and 250°C. It was found that the first distilled fraction (<200°C) corresponding to gasoline fraction increased with the increasing irradiation dose while the second distilled fraction (200-250°C) corresponding to kerosene fraction seems to decrease. The composition of organic phase was also determined by GC-MS.