Migration of Emulsified Water Droplets in Petroleum Sludge during Centrifugation

摘要

Centrifugation is an efficient and environmentally friendly method to recover valuable oil resources from petroleum sludge. In this paper, the Monte Carlo method was used to predict the settling behavior of different-sized water droplets based on the Navier-Stokes equation. Differential scanning calorimetry (DSC) was used to deduce the size distribution of emulsified water droplets in petroleum sludge. Numerical estimation and experimental analysis both show that the water removal rate increases with a rising centrifugal speed. When the centrifugal speed increased from 2000 to 10 000 rpm, the water removal rate increased from 28 to 99%. Meanwhile, the critical separation size of the emulsified water droplet decreased from over 14 μm at 2000 rpm to around 3 μm at 10 000 rpm. The Monte Carlo method was successfully applied to assess the effect of petroleum viscosity and centrifugal speed on the water removal rate, and the simulations are in good agreement with DSC analysis. The results of this study can provide quantitative information and guidance for optimizing the centrifugation of petroleum sludge for oil recovery.