Evaluation of Vinyl Imidazolium Based Ionic Liquids as Flow Improvers for Indian Waxy Crude Oil

Abstract

Abstract The blockages due to wax/paraffin deposition in operational facilities consensus as a billion-dollar problem in Petroleum industry. Moreover, the production shift towards heavy and paraffinic crude oil from extreme climate regions further aggravates the situation. What’s more, the utilization of environmentally hazardous chemicals for mitigation of this severe issue also causes additional threats. Thus, motivated by such a problem, current research endeavor synthesis and application of green chemicals viz. Ionic liquids for mitigation of paraffin deposition. Vinyl imidazolium based Ionic liquids were synthesized by nucleophilic addition of 1-Bromo alkane and Vinyl imidazole. The obtained products further undergo metathesis with Bis (trifluoromethane) sulfonimide lithium salt (LiNTf2) to obtain the final product (IL). The structure of IL was assessed by using Fourier transform infrared (FTIR), 1H NMR, and Differential Scanning Calorimetry (DSC). The effect of IL on pour point was assessed. Further, the IL was evaluated for Microscopic and rheological Studies of petroleum by Polarized Optical Microscopy (POM) and Rheometer respectively. Cold finger test was performed to check Wax deposition potential of Crude oil and Paraffin Inhibition Efficiency of Chemical additive. The results showed that IL demonstrated superior performance in enhancing the flowability of waxy crude oil compared to conventional pour point depressant (PPD) available in the market. The pour point of crude oil could be lowered by as much as 15°C at 500 ppm by using IL compared to commercial PPD which depresses the pour point up to 6°C only at higher concentration (1000 ppm). At 30°C, the viscosity of the waxy crude oil reduced up to 85% after doping crude oil with 500 ppm IL. Cold finger test results revealed that IL can reduce the paraffin deposition up to 54.72%. The results of polarized microscopy showed that with the introduction of IL in the crude oil, the formation of the wax crystals can be greatly reduced. Ionic liquids are emerging as more sustainable and environmentally benign chemical additives for remediation of paraffin deposition which can be implemented successfully in the field for transportation of crude oil and provides direction for building the next generation of Chemical additives for flow assurance of waxy crude oil.