Nanomagnetic Cyclodextrin decorated with ionic liquid as green and reversible Demulsifier for breaking of crude oil emulsions.

Application of the chemical demulsifiers is the best choice for breaking the water in crude oil (W/O) emulsions in the petroleum industry. Here, novel, environmentally friendly, efficient, and easily reusable Fe3O4 nanomagnetic compounds based on imidazolium-decorated cyclodextrin were successfully synthesized and applied to demulsify the water in crude oil (W/O) emulsions. At first, Fe3O4 nanoparticles were decorated with ß-cyclodextrin (ß-CD) to prepare Fe3O4@ß-CD@IL magnetic nanoparticles. Then, imidazole (Im) was separately reacted with 1-bromohexane and 1-bromodecane to prepare [Im-C6][Br] and [Im-C10][Br] ionic liquids, respectively. The prepared imidazolium-based ionic liquids were reacted with N-propyltriethoxysilane to synthesize [ImSi-C6][Br] and [ImSi-C10][Br]. Finally, [ImSi-Cn][Br] was immobilized on Fe3O4@ß-CD to obtain nanomagnetic demulsifiers. Structure of the synthesized compounds was confirmed using different methods such as FT-IR, NMR, and elemental analysis. TGA, VSM, and FESEM methods were used to investigate the thermal stability, magnetic properties, and the morphology, respectively. Fe3O4@ßCD and Fe3O4@ßCD@[ImSi-C10][Br] nanoparticles respectively showed the particle size in the range of 40-70 nm and 50-80 nm. After grafting the imidazolium-based ionic liquid on the surface of support, the magnetization number reduced from 25.6 emu/g for Fe3O4@ß-CD to 24.9 emu/g for Fe3O4@ß-CD@[ImSi-C10][Br]. Synthesized material employed to break the (10:90 and 30:70 Vol%) W/O emulsions at the concentration range of 1000-5000 ppm. The maximum demulsification efficiency (DE%) of 92 % was obtained using a Fe3O4@ß-CD@[ImSi-C10][Br] at 5000 ppm for (30:70 Vol%) W/O emulsion within 24 h. Interfacial tension (IFT) values decreased with increasing the DE%. The Fe3O4@ßCD@[ImSi-C10][Br] demulsifier was reused five times with acceptable yields. The cooperation of imidazolium and ß-CD in the green nanomagnetic demulsifiers led to the efficient demulsification of the W/O emulsions. The preparation of different ionic liquids or changing the counter anions are our potential future directions for this research. Demulsification at high demulsifier concentration can be considered a limitation of the nanomagnetic cyclodextrin decorated with ionic liquid. But due to the low amount of ionic liquid immobilized in the synthesized demulsifier, the cost of the final demulsifier is lower that other demulsifiers with full ionic liquid backbones, which increases its potential for industrial applications.

Demulsification of Crude Oil Emulsions Using Versatile and Eco-Friendly Demulsifiers Based on Cellulose Decorated with Imidazolium-Bearing Triazole Moiety.

Water in the crude oil forms emulsions that must be broken before refining processes. Here, the novel and versatile derivatives of imidazolium ionic liquids (ILs) containing triazole moiety [SIm-TazCn][Br] were synthesized via click chemistry and then grafted onto the cellulose (CEL) to prepare eco-friendly demulsifiers for breaking water-in-oil (W/O) emulsions. The prepared compounds with two kinds of alkyl chains named CEL[SIm-TazC6][Br] and CEL[SIm-TazC10][Br] were characterized and employed for demulsifying W/O (30:70 and 50:50 vol %) emulsions. Also, the effect of the type and concentration of each demulsifier on the phase separation and dehydration efficiency (DE) were investigated through the bottle test. According to the bottle test results, the CEL[SIm-TazC6][Br] derivative at 4000 ppm showed a good DE of 79% after 5 min, which increased to 82% after 24 h. The interfacial tension (IFT) of derivatives at different concentrations was measured. The minimum IFT value of 16.3 mN/m was obtained for CEL[SIm-TazC6][Br] with a shorter alkyl chain at 4000 ppm after 24 h. The green and efficient CEL-based surfactants significantly demulsified the W/O emulsions because of the collaboration between imidazolium and triazole moieties.

Application of imidazolium based ionic liquids grafted on microcrystalline cellulose as demulsifiers for water in crude oil (W/O) emulsions.

Separation of water and oil from water-in-oil (W/O) emulsion before transportation and refining is very important and critical. Ionic liquids (ILs) and their derivatives have recently attracted much attention as efficient chemical agents for breaking emulsions. So, here, a series of microcrystalline cellulose (MCC) grafted with imidazolium-based ionic liquids (IM-ILs) were synthesized, named as MCC@IM-ILs, and evaluated as eco-friendly surface-active agents for the separation of water from the crude oil. Structure of the synthesized compounds was confirmed by different characterization techniques. Dehydration efficiency percent (DE%) of the synthesized demulsifiers was measured and compared with each other. Synthesized MCC@IM-ILs showed an acceptable DE% to demulsify three kinds of W/O emulsions with different water content after 5 min. Concentration, alkyl chain length, and counter-anion of the synthesized MCC@IM-ILs play a key role in separating water from crude oil. Demulsifier with C10 alkyl chain length showed better DE% than the corresponding demulsifier with C6 alkyl chain length in the W/O (30:70 v/v) emulsion. Also, demulsifier with Br counter anion showed lower DE% than the corresponding BF4 ion-exchanged compound with higher hydrophilicity. Synthesized demulsifiers immobilized on ILs have significant advantages compared to unsupported ILs due to the use of green and economical cellulosic substrate.