Effect of different imidazolium ionic liquids on the dispersion of aggregated asphaltene in heavy crude oil

Title : Effect of different imidazolium ionic liquids on the dispersion of aggregated asphaltene in heavy crude oil

Abstract:

Due to the predicted increase in heavy oil production spurred on by energy problems, challenges relating to asphaltene are receiving increased attention. The formation of tough emulsions and blocked wellbores caused by asphaltene precipitation make production operations difficult and reduce the amount of recovered oil. Due to operational issues, safety concerns, and an oil production constraint, the petroleum industry suffers significant financial losses. In the extraction, production, and transportation operations, asphaltene dispersion in crude oil utilising green ionic liquid is being explored as a potential option. Ionic liquids (ILs) have the ability to break-down different types of crude oil emulsions such as water in oil emulsions (tough emulsions) and oil in water ones. ILs have many advantages such as they are eco-friendly and can be recycled. Herein in the presented study, the effect of the prepared ionic liquids on asphaltene aggregates has been investigated to determine the role of different structures of ILs on the dispersion of asphaltene molecules. Therefore, three different ILs containing different lengths of alkyl chains, Imi-C12, Imi-C8, and Imi-C4, were synthesized, characterized via FT-IR and ¹HNMR. Moreover, the surface tension of ILs was measured to determine the critical micelle concentration. The prepared ILs were found to be thermally stable up to 380 ºC after conducting the thermal gravimetric analysis. The dispersion activity of the ILs was investigated using the viscometric method, where n-heptane is used as a precipitant. It was found that using Imi-C12, Imi-C8, and Imi-C4 can delay the asphaltene onset precipitation from 30% to 55, 65, and 70 %, respectively. As a result of their interaction with asphaltene molecules and formation of steric stabilising layers surrounding them, ionic liquids with long alkyl tails (> eight carbon chains) are efficient asphaltene dispersants that lower oil viscosity and asphaltene aggregates. To avoid asphaltene aggregation in petroleum feed streams, ionic liquids can be used as an environmentally friendly chemical substitute for surfactants.

Biography:

Dr. Raghda El-Nagar studied Chemistry at the Zagazig University, Egypt and graduated in 2009. She then joined the research group at the Egyptian Petroleum Research Institute, Cairo, Egypt. She received her MSc degree in 2013 and his PhD degree in 2018 at Ain Shams University. Dr. Raghda El-Nagar is a Researcher - Oil Testing Lab - Analysis and Evaluation Department. Senior of Oil lab analysis in Central Lab Services Center with over 14 years of experience providing technical support concerning routine petrolieum studies to over 25 petroleum companies in Egypt, Sudan, South Africa and Chad. She has published more than 20 research articles in SCI(E) journals.