Alginite rock as effective demulsifier to separate water from various crude oil emulsions

Abstract

Due to environmental restriction laws in oil production and processing, there is a high demand for the oil industry to reduce the use of chemical demulsifiers and to employ safer, less toxic materials. The purpose of this research is to investigate whether Alginite, a naturally occurring and abundant oil-shale rock, can be utilised as an alternative, environmentally friendly and low-cost material to demulsify various water-in-crude oil emulsions (W/O). Three W/O emulsions were prepared using saline water with respectively light, medium and heavy crude oils. The properties of the crude oils were analysed and the effectiveness of Alginite to demulsify the corresponding W/O emulsions was investigated. The results confirm that naturally occuring Alginite exhibits exceptional water-removing capacity even from emulsions containing heavy crude oil, leaving only < 1.0 wt.-% water in the remaining demulsified oil, which satisfies the required specification for industrial applications. Alginite was shown to reduce viscosity and to deform the dispersed phase in W/O emulsions even in the absence of flow. The results of this work indicate that Alginite is of significant interest in petroleum research, in industrial oil processing as well as in environmental remediation.