Effect of composite additives on microwave-assisted pyrolysis of microalgae

The effect of composite additives on the pyrolysis characteristics of microalgae (Dunaliella salina) was studied by microwave-assisted pyrolysis system. The composite additive was blended by SiC and CaO. The three cases, i.e. different kinds of additives (single additive and composite additive), different addition amounts (5%, 10%, 15%, 20%, and 25%) of composite additives, and different blending ratios (SiC/CaO = 0:10, 3:7, 5:5, and 7:3) were investigated. The results show that when the composite additive was 15% and the blending ratio of SiC/CaO = 5:5, the average weight loss rate (R-v) and weight loss rate for the second peak (R-p2) were maximum, while the final time detected as weight stabilization (t(f)) and the time corresponding to second peak (t(p2)) were minimum. Besides, SiC and CaO had a synergistic effect in this experimental condition. When the additive was 7.5% SiC, the total weight loss (M-t) and the weight loss rate for the first peak (R-p1) were maximum and the time corresponding to first peak (t(p1)) was minimum. The minimum R-v and M-t occurred at 7.5% CaO group.