Development of Local Demulsifier for the Treatment of Crude Oil Emulsion

The presence of emulsion in crude oil presents a flow assurance problems, part of which is raising the bulk fluid's viscosity. Almost every part of the oil production and processing chain is susceptible to emulsions because of the ubiquitous presence of water in the production process. Water in crude oil may have unintended consequences such as increased corrosion rate, higher conductivity, and subtle leaching of additives. To reduce the corrosion rate and prevent catalyst poisoning at downstream processing facilities and to meet crude standards from storage to export, the emulsion needs to be treated to remove the distributed water and associated inorganic salts. The Niger Delta being one of the leading oil producing regions in Nigeria and in the world has remained dependent on foreign demulsifiers for the treatment of crude oil emulsions. Some of these chemicals may not be environmentally friendly due to their constituent elements which may not be readily biodegradable. Thus, there is the need for a readily biodegradable materials for the formulation of environmentally friendly demulsifier for the treatment of Niger Delta crude oil.From studies, most agro-based oils are rich in fatty acids and non-saturated fats that can be blended with other materials to produce a surface-active compound that can break the interfacial surface of the water droplets and coalesce with each other. Three demulsifier blends X1, X2 and X3 were prepared using different ratios of palm kernel oil, cashew nut oil, liquid soap, locally prepared starch and Calcium Hydroxide. Blend X1contains 40% of palm kernel oil, 40% of cashew nut oil, blend X2 contains 50% of palm kernel oil and 30% of cashew nut oil while blend X3 contains 30% of palm kernel oil and 50% cashew nut oil. The percentage of liquid soap, starch, calcium hydroxide and water is the same in each of the three blends. All three blends were used as demulsifier individually to separate water droplets in oil and they individually performed optimally at 0.6 ml within 30 minutes in this work. The imported demulsifier used for comparison in this study is polydimethylsiloxane (PDMS) which took nearly 120 minutes at 1.0 – 1.4 ml to yield the same results as the locally prepared demulsifiers. A maximum of 15.5 ml resulting to 15.5 % of water was released from the crude oil emulsion using the locally blended demulsifiers. The quality of oil and water separated after demulsification with the various local blends shows that all the blends produced good oil quality with sharp oil - water interface and complete separation within 30 to 120 minutes. The results were in line with the specification allowable for the BS&W contained in crude oil for export and the local refineries as stipulated by the Nigerian Upstream Petroleum Regulatory Commission (NUPRC)