Catalytic Pyrolysis of Soybean Oil with CaO/Bio-Char Based Catalyst to Produce High Quality Biofuel

Abstract

In this paper, CaO/bio-char was synthesized by directly co-pyrolysis of Ca(OH)2 and rice straw, and used as catalyst to catalytic pyrolysis of soybean oil to produce high quality biofuel. In this co-pyrolysis process, CaO particles has been successfully embedded on the bio-char surface. During the catalytic pyrolysis process, CaO/bio-char showed a good catalytic performance on the deoxygenation of soybean oil. Pyrolysis temperature affected the pyrolysis reactions and pyrolytic products distributions dramatically, higher pyrolysis temperature lead to seriously cracking reactions, lower bio-oil yield and higher gases yield, and lower pyrolysis temperature lead to higher bio-oil yield with higher oxygenated compounds content and lower hydrocarbons contents, the suitable pyrolysis temperature was around 650°C. Under the optimal conditions (650°C with WHSV at 6.4 h−1 and carrier gas flow rate at 100 ml/min), the selectivity (%) of hydrocarbons in the bio-oil was more than 90%. CaO/bio-char catalyst still shows good catalytic deoxygenation activity after 4 cycles. 1 g of CaO/bio-char catalyst can catalyze pyrolysis of 32 g of soybean oil to produce high-quality liquid fuel. Bio-char based catalyst has been proved to be a promising catalyst for catalytic conversion of triglyceride-based lipids into high quality liquid biofuel.