Optimising the chemical demulsification of water-in-crude oil emulsion using the Taguchi method

Abstract

This study examines the effect of important factors such as the temperature, pH, freshwater, concentration, and type of demulsifier on chemical demulsification (CD) using the bottle test method. Three Iraqi heavy crude oils, each with different properties, were tested. Each of these samples contained different concentrations of salt solution, which need to be removed to improve the properties of the crude oil. Five different types of commercial chemical demulsifiers, namely oxyalkylated copolyether (D1), Polyethylene glycol octaadacyl ether (D2), polyether butoxy ethanol (D3), Ethylene-propylene copolymer (D4), and Cumene 1,2,4-trimethylbenzen (D5), were tested. The Taguchi method was used to design the experiments to obtain optimum separation. The data analysis was carried out using signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The results of the best combination test show that the maximum removal efficiency of CD for the three samples are 94.2%, 95%, and 92%, respectively. In addition, there was a noticeable improvement in the original values of the API from 23.2 to 28.4, 14 to 20.9, and 4.6 to 24.1, respectively. The work plan and the results of this work could be used to improve crude oil processing in the Iraqi oil industry.