Comprehensive experimental study on supercritical water gasification of oilfield sludge: Effect of operation parameters, and catalysts on the products

Supercritical water gasification (SCWG) was adopted to treat oilfield sludge and produce syngas. The effect of temperature (400-450 & DEG;C), reaction time (30-90 min) and catalyst addition on syngas production and residual products during SCWG of oilfield sludge was studied. When increasing SCWG temperature from 400 to 450 & DEG;C with reaction time of 60 min, the H2 yield and the selectivity of H2 increased significantly from 0.53 mol/kg and 75.53% to 0.98 mol/kg and 78.09%, respectively. It is noteworthy that when the reaction time was too long, CO2 and CO were converted to CH4 with the consumption of H2 via methanation reaction. The addition of Ni/Al2O3 catalyst can substantially promote the production of high-quality syngas from SCWG of oilfield sludge. The H2 yield and its selectivity at 450 & DEG;C and 60 min were as high as 1.37 mol/kg and 84.05% with 10Ni/Al catalyst. Moreover, the catalysts with bimetal loading (Fe-Ni, Rb-Ni or Ce-Ni) were found to be beneficial for improving gasification efficiency, H2 yield, and the degradation of organic compounds. Among them, 5 wt% Rb on 10Ni/Al catalyst performed the best

Automated summary

Supercritical water gasification (SCWG) was used to treat oilfield sludge and produce syngas. The effect of temperature, reaction time, and catalyst addition on the production of syngas and residual products during SCWG of oilfield sludge was investigated. It was found that increasing the temperature and adding Ni/Al2O3 catalyst significantly improved the yield and selectivity of H2 in the syngas.