Review on the Fundamental Aspects of Petroleum Oil Emulsions and Techniques of Demulsification

Abstract

This review is aimed to introduce a comprehensive survey on the most prominent and sustainable techniques and methods that could abate the environmental worries as well as financial insecurities in treating petroleum emulsions, since the existence of water is not desired because of the paramount troubles it may cause on the processing streamlines, as well as financial cost associated with transporting water mixed with petroleum. Currently, the most commonly used method for treating petroleum emulsion is the application of chemical additives, known as demulsifiers. Althogh, there are many other methods that are claimed to be more favorable from economic and environmental perspectives, yet, have not being fully put into real life practice, because of the drawbacks and disadvantages. In this review, several techniques have been surveyed including, chemical, electrical, membrane, centrifuge, bacteria, air floatation, ultrasonic, and microwave. Based on this Theoretical survey, silcone based demulsifiers were reported to be very effective and environmental friendly, but expensive. Also microwave and ultrasonics were reported to be very effective in treating petroleum emulsion and could be recommended as future ulternatives for treating petroleum emulsions.

Chemical Demulsification of Model Water-in-Oil Emulsions With Low Water Content by Means of Ionic Liquids

“…In fact, emulsified water can corrode refinery equipment and the water-dissolved salts can poison catalysts in downstream processing facilities (Issaka et al, 2015;Sullivan et al, 2007). Additionally, w/o emulsions usually exhibit viscosities significantly higher than crude oil, thus increasing the pumping costs for the transport of oil in pipelines (Peña et al, 2005).…”

“…Surface active agents commonly occurring in crude oils, such as asphaltenes, resins, waxes and solid particles, form rigid films at the water-oil interface, which prevent the coalescence of water droplets (de Oliveira et al, 2010;Fortuny et al, 2007;Issaka et al, 2015;Schramm, 1992;Silva et al, 2013;Sjӧblom et al, 2003;Yang et al, 2009). Numerous techniques are currently available for breaking w/o emulsions, including mechanical methods (e.g., gravity settlers or centrifugal separators), application of electric Brazilian Journal of Chemical Engineering fields (electrocoalescers), conventional heating and microwave demulsification, pH adjustment, membrane separation and chemical demulsification (Abdurahman et al, 2007;Djuve et al, 2001;Ekott and Akpabio, 2010;Guzmán-Lucero et al, 2010;Hajivand and Vaziri, 2015;Issaka et al, 2015;Yang et al, 2009). The mechanical separators and electrostatic grids commonly adopted for the destabilization of crude oil emulsions have high equipment volume and high cost for the installation on offshore platforms as main drawbacks (Ekott and Akpabio, 2010).…”

“…The application of chemical demulsifiers is one of the most common strategies applied for resolving w/o emulsions, and it involves the use of amphiphilic molecules which, thanks to their interfacial activity, accelerate the interfacial film rupture, thus promoting the flocculation and coalescence of the water droplets (Abdurahman et al, 2007;Cendejas et al, 2013;Djuve et al, 2001;Ekott and Akpabio, 2010;Guzmán-Lucero et al, 2010;Kang et al, 2006;Issaka et al, 2015;Silva et al, 2013). The main advantage of chemical demulsification relies on the possibility of its easy integration into already existing w/o separation units without the need of equipment shutdown and with relatively small capital costs (Ekott and Akpabio, 2010).…”

“…The main advantage of chemical demulsification relies on the possibility of its easy integration into already existing w/o separation units without the need of equipment shutdown and with relatively small capital costs (Ekott and Akpabio, 2010). Different classes of demulsifiers are commercially available including co-polymers of polyoxyethylene and polyoxypropylene or alkylphenol-formaldehyde resins, alkoxylated amines, or mixtures of them (Cendejas et al, 2013;Guzmán-Lucero et al, 2010;Issaka et al, 2015). Current research efforts are focused on the development of cost-effective and environmentally friendly chemical demulsifiers characterized by high water separation efficiency and demulsification rate, so as to meet the oil company specifications (the maximum allowable water cut in crude oil is generally 0.1-0.5%) (AbdulWahab et al, 2006;Cendejas et al, 2013;Guzmán-Lucero et al, 2010;Issaka et al, 2015).…”

“…Different classes of demulsifiers are commercially available including co-polymers of polyoxyethylene and polyoxypropylene or alkylphenol-formaldehyde resins, alkoxylated amines, or mixtures of them (Cendejas et al, 2013;Guzmán-Lucero et al, 2010;Issaka et al, 2015). Current research efforts are focused on the development of cost-effective and environmentally friendly chemical demulsifiers characterized by high water separation efficiency and demulsification rate, so as to meet the oil company specifications (the maximum allowable water cut in crude oil is generally 0.1-0.5%) (AbdulWahab et al, 2006;Cendejas et al, 2013;Guzmán-Lucero et al, 2010;Issaka et al, 2015). In addition, the combination of chemical demulsifiers with microwave or ultrasound, which accelerate the water separation process, is considered to be an attractive route to minimize the dosage of chemicals and consequently their utilization cost (Issaka et al, 2015).…”