Upgrading of Heavy Oil Components using Modified Iionic Liquids with Fe3+ and Al3+ Salts

Owing to the catalytic properties of ionic liquids (ILs), they might break down the asphaltene and resin molecule structures, and consequently, they will result in upgrading the heavy oil cuts. The superiority of using ILs to other techniques of upgrading is (1) the low operating condition and (2) the lack of negative effects of sulfur compounds and heavy metals on the catalytic role of ionic liquids. In this study, the capability of conversion the heavy oil cuts into light cuts via an IL([OMIM][Cl]) and two modified ILs, which have been modified with iron and aluminum salts, has been investigated. The viscosity, asphaltic percentage and sulfur content were analyzed for characterization of the physicochemical properties of the heavy oil cuts. Furthermore, the influences of several parameters such as the type of heavy oil cuts, the temperature of reaction, the residence time and the percentage of utilization of modified ILs on the quality of heavy oil cuts were evaluated by Minitab software. The results indicated that the presence of Fe and Al in the structure of modified ILs ([OMIM][FeCl3] and [OMIM][AlCl3]) could significantly enhance the capability of these ionic liquids in improving the quality of heavy oil cuts. This resulted in decreasing the value of viscosity and the pollutants containing sulfur and nitrogen compounds in heavy oil cuts. It was observed that the percentage of utilization of modified ILs was the most effective in upgrading of heavy oil cuts. Based on the results at the best condition, the modified ILs of [OMIM][FeCl3] and [OMIM][AlCl3] could reduce 74.44% and 41.80% of the viscosity value and 57.17% and 68.46% of the asphaltene content in the heavy oil cuts respectively. Moreover, the sulfur content in the heavy oil cuts decreased from 2.9% to 1.43% and 0.95% respectively. In the same operating conditions, IL modified with [AlCl3] showed the better performance than one modified by [FeCl3] in increasing the quality of heavy oil cuts. This relative superiority can be attributed to the high value of acidity of AlCl3 in comparison with FeCl3 and the closeness of the binding energy level of Al to sulfur. In conclusion, in this study, it is illustrated that the modified ILs can be considered to be a suitable approach for upgrading the quality of heavy oil cuts at moderate condition.