Cement Catalyzed Valorization of Rice Straw into Upgraded Bio-Oil and Fuel Gases Using Pyrolysis Reactions

Abstract

ABSTRACT Rice straw is one of the major agricultural residues that is generated enormously in Asian countries. Thus, it is critical to develop an efficient process of converting this residue into valuable compounds in replacing fossil-based products. Herein, we developed an economically viable cement catalyst to pyrolyze the rice straw into bio-oil and fuel gas in a batch-type reactor. Under the optimized conditions, the maximum bio-oil yield of 41.07 wt.%, and gas yield of 30.53 wt.% along with a biochar yield of 28.41 wt.% is achieved at 600°C. The catalyst showed a considerable effect on the bio-oil composition. It improved hydrocarbons quantities while using the optimum cement dosage at 600°C, and enhanced H2 from 18.79% to 25.57. By further increasing the catalyst dosage to 15 wt.%, the H2 yield was enhanced to 28.35%. The BET specific surface area of char at the optimum temperature was 76.42 m2/g and fine pore size. Catalyst improved both the yield and quality of the bio-oil. The bio-oil quality was enhanced by lowering the oxygen contents to a smaller value as 7.0098% and no water at all.