Removal of Water from Water-in-crude Oil Emulsions with Poly[(acrylic acid)-co-(sodium acrylate)] as Water-absorptive-polymers

Abstract

Removal of water from water-in-crude oil (W/O) emulsions was investigated using poly[(acrylic acid)-co-(sodium acrylate)］as water-absorptive-polymer (WAP) at 15-70 °C and under 0.1-1.5 MPa employing a batch or a flow separation system. The W/O emulsions with water content of 1-5 mass% were prepared from Upper Zakum (UZ) crude oil reserved at a domestic oil stockpiling base and distilled water. In each separation system, water absorption rates of both granular and fibrous WAPs from W/O emulsions under ambient conditions were much faster than that of zeolite 4A, indicating an effectiveness of WAPs for water separation. Removal of water from W/O emulsions was enhanced at high temperatures (50-70 °C) and under high pressures (1.0-1.5 MPa). It was found that regeneration of used WAPs was possible by rinsing them in toluene followed by drying. These results indicate that absorption of water from W/O emulsion using WAP is considered as one of the promising physical demulsification methods such as centrifugal separation, thermal treatment, and gravitational sedimentation without using chemical demulsifier.