Study on pyrolysis of oil sludge with microalgae residue additive

The pyrolysis of oil sludge (OS) with microalgae residue (MR) additive was conducted with a TGA and a tube furnace. The pyrolysis process of OS with the MR additive can be divided into three stages: 1) water evaporation, 2) the release of light groups of hydrocarbon compounds, the cracking of heavy groups, and carbon decomposition, and 3) minerals decomposition. With the MR addition ratio increasing, the yield of oil and gas increased, and oil to gas ratio increased during OS pyrolysis. The MR addition improved the quality of pyrolysis oil and gas from OS pyrolysis. The proportion of light oil increased from 38 % with a 5 % MR addition ratio to 45 % with a 30 % addition ratio. Major components of pyrolysis gas included H2, CO, CO2, and CxHy. With the increase of the MR blending ratio, CO and CO2 contents increased, while H2 and CxHy contents decreased. Adding MR favoured the transformation of heavy hydrocarbons (C6+), resulting in a high content of light hydrocarbons. This work can help promote massive synergistic treatment of OS and microalgae biomass.