Microwave catalytic pyrolysis production and characterization of Chlorella vulgaris under different compound additives

Microwave-assisted catalytic pyrolysis of Chlorella vulgaris was investigated under two compound additives blended of graphite (GP) with Fe2O3 (Fe/GP) and ZSM-5 (ZM/GP). The effects of pyrolysis properties and products yields were evaluated using 10% of additives with different blending ratios (0:10, 3:7, 5:5, 7:3, and 10:0). The results showed that for the compound additives of Fe/GP, the maximum weight loss rate (Rm), the total weight loss (Mt) and bio-oil yield (Yu) of Chlorella vulgaris got the maximum value at a Fe2O3/GP ratio of 3:7 (sample Fe3GP7). As for ZM/GP, ZM5GP5 showed the strongest promoting effect based on Rm, Mt and Yu. In terms of energy consumption, the addition of compound additives can significantly reduce the energy consumption. Fe3GP7 and ZM5GP5 had the smallest energy consumption per unit of bio-oil (Wu). The results of GCMS analysis indicated that compound additives brought down the ratio of nitrogen-containing compounds and increased aromatic compounds in bio-oil. Moreover, ZM5GP5 showed more benefits compared to Fe3GP7 of this aspect.

Automated summary

In this study, microwave-assisted catalytic pyrolysis of Chlorella vulgaris was conducted with compound additives Fe3GP7 and ZM5GP5, which showed significant improvements in bio-oil yield and energy consumption reduction. The compound additives decreased the ratio of nitrogen-containing compounds and increased aromatic compounds in the bio-oil.