Microwave catalytic co-pyrolysis of sugarcane bagasse and Chlorella vulgaris over composite catalyst: Characteristics and bio-oil analysis

Abstract

Microwave co-pyrolysis of Chlorella vulgaris (CV) and bagasse (BA) with composite additives (the mixing of two or more single catalysts) can effectively improve the pyrolysis characteristics and the quality of bio-oil. In this study, a composite catalyst B1O1 was prepared by bio-char (BC) and calcium oxide (CaO) at the ratio of 1:1. The comparison between the effects of B1O1 and two single catalysts (BC and CaO), at different addition amounts (10 %, 20 %, 30 %, 40 % and 50 %) was investigated. Also, the effect of the interaction between BC and CaO during co-pyrolysis was analyzed. The results showed that the B1O1 composite catalyst can effectively improve the co-pyrolysis characteristics, and the maximum weight loss rate (R_m, 0.11106 wt%/s) and the maximum average weight loss rate (R_v, 0.02674 wt%/s) were obtained at 50 % B1O1. Moreover, at 40 % B1O1, the bio-oil yield reached the highest (23.50 %). Finally, GC-MS analysis showed that, under 40 % B1O1, the content of nitrogen and oxygen containing compounds in bio-oil was reduced by 1.85 % and 8.99 %, respectively, while the hydrocarbons content was increased by 14.17 %.