Microwave catalytic co-pyrolysis of chlorella vulgaris and oily sludge by nickel-X (X = Cu, Fe) supported on activated carbon: Characteristic and bio-oil analysis

Abstract

Microwave co-pyrolysis of chlorella vulgaris (CV) and oily sludge (OS) was conducive to improving pyrolysis characteristics and bio-oil quality. In this study, activated carbon (AC) was used as carrier to prepare metal supported catalysts (Ni/AC, Ni–Cu/AC and Ni–Fe/AC), and the effects of catalysts with different additions (5%, 10% and 15%) on co-pyrolysis of CV and OS were investigated by microwave pyrolysis furnace. The results indicated that metal supported catalysts improved the co-pyrolysis characteristics, especially at 10% addition amount. The maximum average rate of weight loss (Rv) and minimum reaction time (Ts) occurred in the 10% Ni–Fe/AC group. Moreover, addition of 10% metal supported catalysts showed promoting effect on producing bio-oil, and the maximum bio-oil yield (22.1%) obtained in the 10% Ni–Cu/AC group. GC-MS analysis indicated that addition of 10% Ni–Fe/AC increased aliphatic hydrocarbons in bio-oil to 44.52%, while 10% Ni/AC increased hydrocarbons to 76.62%. Furthermore, the deoxidization efficiency of bio-oil exceeded 35% with metal supported catalysts adding. The maximum deoxidization efficiency (46.57%) was obtained when adding 10% Ni–Fe/AC.