Treatment of oily sludge through multiphase compound conditioning and demulsification separation process

Oily sludge widely exists in the petroleum exploration, petrochemical processing and application. Because of its high viscosity, complex and stable emulsification characteristics, the treatment of oily sludge is fairly difficult with low treatment efficiency. Aiming at the problem of low separation efficiency of traditional process, this study put forward the resourceful treatment of oily sludge through multiphase compound conditioning and demulsification separation process, based on the engineering application. Firstly, the different viscosity reduction methods of oily sludge was studied. It was found that the viscosity of oily sludge could be effectively reduced by multiphase composite method, owning to the control of the emulsification state, the dissolution of the heavy components and the destruction of its spatial structure. On this basis, the resourceful treatment of oily sludge was carried out by the combination of multiphase compound conditioning and demulsification, and the influence of conditioning and demulsification process on the treatment effect was studied respectively. The results showed that the addition of water could assist the conditioning process to reduce the viscosity effectively, help disperse oily sludge aggregates and promote the dissolution and mass transfer of heavy oil. The oil was dissolved and liberated from the solid surface by the solvent. Through the control of the emulsification state and the use of high-efficiency demulsifier, the efficient separation of oil, water and solid could be realized. When the solvent dosage was 130% and the water dosage was 30%, the system was in water-in-oil state. After adding 400mg/kg water-in-oil demulsifier TJU-3, the heavy oil recovery could reach to 92.9%, and the oil phase was clean. This study could provide reference for the large-scale resource recovery and treatment of oily sludge. © 2023 Chemical Industry Press. All rights reserved.