Freshly Milled Quartz Particles Obtained from River Sand as an Efficient Natural Demulsifier for Crude Oil Emulsions

Abstract

Saline water necessarily contained in crude oil forms complex and stable water-in-oil (w/o) emulsions with oil. Due to the negative impact of this emulsion on the oil’s transportation and refining, special materials are added to help break the emulsion and separate water. Herein, a comparative study of the demulsifying ability concerning w/o emulsion of the original and freshly milled quartz (FMQ) particles isolated from river sand was carried out. The effect of quartz with a mesh size of 75 μm on reducing emulsion stability was investigated using rheological measurements, interfacial tension measurements, demulsification tests, as well as routine methods for characterizing solid and liquid materials. With the addition of 3 wt% FMQ, 97% demulsification efficiency was achieved after 100 min of settling, against 140 min for the original quartz. The role of milling quartz is to increase the ability of water to adhere and thus locally increase the pH value; this results in a reduction in the stability of the emulsion and its destruction. The prolonging effect of quartz milling lasted about 2.5–3.0 h, after which the demulsifying ability of milled quartz became comparable to that of the starting material.