Simulation of Scale Formation During Viscous Oil Wastewater Evaporation and Concentration

Abstract:

The behavior of scale formation during viscous oil wastewater evaporation process was investigated. Based on evaporation and concentration experiments, the composition of scale crystal was confirmed by X ray powder diffractometer (XRD) and scanning electron microscopy (SEM). According to the composition of wastewater scale, a three layer crystallization fouling deposit model was established, namely mixed fouling including calcium carbonate salt(CaCO3), compound salts (Na2CaSiO4, Ca8Si5O18) and silicate salt (Ca2SiO4). It is found that the fouling resistance mainly results from calcium carbonate salt, and it accounts for 91.76% of the total fouling resistance. The simulation results coincide with the experimental data. The three layer crystallization fouling model proves to be able to predict the scale formation process during viscous oil wastewater evaporation, and it provides a theoretical basis for preventing heat transfer surface fouling during evaporation of viscous oil wastewater.