Renewable production of nitrogen-containing compounds and hydrocarbons from catalytic microwave-assisted pyrolysis of chlorella over metal-doped HZSM-5 catalysts

In this work, we evaluated the potential for the production of nitrogen-containing compounds (NCCs) and hydrocarbons by investigating the effects of different metal-doped catalysts (Zn/Cu/Ni/HZSM-5) on catalytic pyrolysis of chlorella using microwave heating. All bio-oils exhibited stratification with the upper/lower layer corresponding to the oil/water phase. The results showed that NCCs and hydrocarbons were the most abundant in the oil phase. The yields of these compounds were enhanced by the application of Zn/HZSM-5 and Cu/HZSM-5, reaching 55.5 area% and 47.5 area%, respectively, compared with the unmodified HZSM-5 (40.9 area%). In the water phase, the NCCs content achieved 42.3 area% with Zn/HZSM-5, 29.6 area% with Cu/HZSM-5, and 39.5 area% with Ni/HZSM-5, respectively, all higher compared with the unmodified HZSM-5 (22.4 area%). This study provides an effective method for green production of NCCs and hydrocarbons that are important structural components in many industries and promotes the application of biomass resources.