Ex-situ catalytic upgrading of vapors from fast microwave-assisted co-pyrolysis of Chromolaena odorata and soybean soapstock

Abstract Fast microwave-assisted catalytic co-pyrolysis of Chromolaena odorata ( C. odorata ) and soybean soapstock with HZSM-5 as an ex-situ catalyst was investigated. Effects of catalytic temperature, feedstock: catalyst ratio and C. odorata : soybean soapstock ratio on the yield and composition of the bio-oil were discussed. Results showed that catalytic temperature greatly influenced the bio-oil yield. Co-pyrolysis of C. odorata and soybean soapstock improved the bio-oil yield, and the maximum bio-oil yield of 55.14% was obtained at 250 °C. However, the addition of HZSM-5 decreased bio-oil yield but improved the quality of bio-oil. Moreover, the proportion of oxygen-containing compounds decreased dramatically with the addition of soybean soapstock. The C. odorata : soybean soapstock ratio of 1:2 and feedstock: catalyst ratio of 2:1 were the optimal condition to upgrade the bio-oil. In addition, the resulted biochar contained various essential elements and could be used as soil repair agent.