Effect of nano-metal oxides types on oil sludge during microwave pyrolysis

ABSTRACT

In this paper, based on the analysis of oil sludge composition and environmental hazards, the microwave catalytic pyrolysis of oil sludge for recovering combustible gas and chain hydrocarbon light oil disposal process, is proposed to perform the recycling of oil sludge and reduce the risk of environmental pollution. In order to improve the yield of combustible gas and light oil in oil sludge pyrolysis, the impact of adding four catalysts (nano-CuO, nano-NiO, nano-MgO, and nano-γ-Al₂O₃) on the heating characteristics of oil sludge and the composition and quality of products during microwave pyrolysis, were experimentally studied and analyzed. The results show that the catalyst can increase the heating rate of sludge and the yield of pyrolysis oil and gas. The increasing order of heating is: nano-CuO > nano-γ-Al₂O₃ > nano-MgO > nano-NiO > blank group. Compared with the blank group, the content of combustible gas (H₂ + CH₄ + CO) increases by 18.824wt% (MgO), 4.511wt% (CuO), 9.28wt% (NiO), and 16.164wt% (γ-Al₂O₃), respectively. It can be deduced that nano-metal oxide catalysts, especially γ-Al₂O₃, can promote the decomposition of oil sludge, improve the content of low carbon straight chain hydrocarbons and alcohols, and improve the quality of pyrolysis oil products.

Keywords
Oily sludge; Microwave pyrolysis; Nano-metal oxides; Wave absorbent