Evaluation of a naturally derived waste brown oil extract for demulsification of crude oil emulsion

Emmanuel E Okoro,Kevin C Igwilo,Samuel E Sanni,Eze F Ahuekwe,Chinedu G Nnaji

doi:10.1177/0144598720905080

Abstract

Conventional methods of eliminating water from crude oil such as the chemical injection have both economic and environmental impacts; thus, this study proposed an economic and environmentally friendly demulsifier. The bottle test method was used to study the performance of the natural extract and commercial demulsifier on a crude oil sample. The GC-MS profile of the extract was in agreement with previous reports on composition of oil extracted from rice bran using hexane, ultrasound assisted extraction and conventional solvent extraction with ethanol. Varying degrees of saturated and unsaturated fatty acids as well as retention times as observed, was a function of total time of scanning, according to NIST08 library of mass spectra. The performance of the demulsifier was expressed in terms of percentage of water separated from 100 ml samples of the oil samples. For both the demulsifiers, the performance increased with increase in volume of the demulsifier, separation time and operating temperature. The extracted demulsifier performed better than the chemical demulsifier under all the experimental conditions adopted in this study. Based on the parametric evaluation, it was observed the results from software corroborated the results obtained from experiments in terms of the observations of the combined effect of temperature and volume which showed the most significant influence on demulsification of the emulsified crude. The highest efficiency of the bio-demulsifier was obtained with a volume of 5 mL of the extract, at a temperature of 70°C and separation time of 60 min. A water separation efficiency of 85.6% was obtained as compared to the chemical demulsifier, which gave an efficiency of 80.2%.

Highlights

Flow assurance provides an economic approach to the production and transportation of fluids from a hydrocarbon well to a process plant
The objective of this study is to address at least one of the above or other disadvantages associated with the prior art, by using a bio-waste extract to formulate a demulsifier that effectively separates water from crude oil without altering the chemical and physical properties of the hydrocarbon
The gas chromatography/mass (GC-MS) analysis shows that the main compositions and constituents of the extracted demulsifier are octadecanoic acid (49.884%) and n-hexaneoic acid (22.951%) which are able to break water-in-oil emulsion

Summary

Introduction

Flow assurance provides an economic approach to the production and transportation of fluids from a hydrocarbon well to a process plant. The emulsion produced must be fragmented to separate the crude oil from water. The breaking of these emulsions by physical or chemical methods can be very expensive, especially for crude oil emulsions that contain emulsionstabilizers, such as naphthenic acids or asphaltenes (Nyden et al, 2003). It is important to develop profitable/innovative flow management strategies for controlling emulsions in order to minimize economic risks during the productive life of the field, and to avoid an increase in overhead costs that may accrue from crude oil processing and refining (Grace, 1992; Okoro et al, 2019). Chemical demulsification approach is the most often applied technique in the petroleum industry among mechanical, thermal, electrical, filtration and chemical-flotation treatment methods (Atta et al, 2016; Efeovbokham et al, 2013)

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Conclusion