Ionic Liquids as Demulsifiers of Water-in-Crude Oil Emulsions: Study of the Microwave Effect

Abstract

Water/oil emulsions are formed in oil wells because of the presence of natural surfactants, such as asphaltenes and resins. These molecules strongly stabilize the water/oil interface and prevent coalescence of water droplets. Because water/oil phase separation is necessary before oil refining, surfactants are used to break water/oil emulsions. Herein, surface-active ionic liquids were synthesized and evaluated for the first time as demulsifier agents for water-in-crude oil emulsions of light, heavy, and ultra-heavy Mexican crude oil under conventional and microwave dielectric heating. The use of microwave irradiation accelerated and increased significantly the efficiency of demulsification of ultra-heavy crude oil emulsion.

Phase Equilibria for Binary Systems Containing Ionic Liquid With Water or Hydrocarbons

“…In addition, ILs are potentially toxic and can accumulate in organisms due to their lipophilicity (Ranke et al, 2007;Salminen et al, 2007;Torrecilla et al, 2010;Petkovic et al, 2011). Recent applications of ILs in the oil industry have demonstrated the performance of a set of ILs as demulsifiers during oil-water separation processes (Guzman-Lucero et al 2010;Lemos et al 2010). However, after the oil-water separation, it is unclear why some ionic liquids perform better as demulsifiers.…”

Current Knowledge and Potential Applications of Ionic Liquids in the Petroleum Industry

“…Therefore, it is still one of the most frequently studied subjects in order to find efficient industrial methods to easily and economically break emulsions and desalts crude oil (Xu et al, 2006). The self-organization, micelle formation and surface properties of ionic liquids (Luczak et al, 2008) as well as their use to dehydrate and desalt crude oil have been just recently reported (Guzmán-Lucero et al, 2010;Lemos et al, 2010). These research groups work on the demulsification of water-in-medium, heavy and extra-heavy crude oil emulsions assisted by conventional and microwave assisted heating.…”

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

“…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).…”