Influence of microwave power, metal oxides and metal salts on the pyrolysis of algae

The work was to investigate the influence of microwave power, metal oxides and metal salts onto the pyrolysis of algae (4.55 wt.% moisture). It was found that the heating rate and the final temperature would increase as enhancing the microwave power. When microwave power increased from 750 W to 2250 W, the yield of solid residue decreased by 22.05%, and gas yield increased 39.45%. After adding 5% (mass basis) CuO and MgO, the yield of solid residue and bio-oil appeared the greatest decreasing ranges of 14.35% and 11.04%, respectively. Electrical energy consumption increased by 1.44% and reduced by 40.76% after CuO and MgO was added, separately. When algae was mixed with 5% (mass basis) MgCl2, ZnCl2 and NaH2PO3, respectively, the yield of solid residue increased by 3.98%, 1.13% and 2.31%, and the bio-oil yield increased by 6.3%, 16.92% and 0.71%, respectively. The effect of microwave absorption was ZnCl2 > NaH2PO3 > MgCl2.