Novel Synthesis of Choline-Based Amino Acid Ionic Liquids and Their Applications for Separating Asphalt from Carbonate Rocks

Zisheng Zhang,Xingang Li,Ning Kang,Lin He,Jingjing Zhou,Hong Sui

doi:10.3390/nano9040504

Abstract

In this study, a series of choline-based amino acid ionic liquids have been synthesized in an economic method and are used to assist solvents with extracting asphalt from carbonate rocks. All of the ionic liquids perform well in extracting asphalt, especially choline histidine, by which the single-step recovery of asphalt is up to 91%. Furthermore, oil product with higher quality (fewer solids entrained) is also obtained. Molecular dynamics simulation and thermodynamic equilibrium method are applied to investigate the role of amino acid ionic liquids via interaction energy calculation and surface free energy calculations. The simulation results suggest that the ionic liquid phase is beneficial for the transfer of oil fraction from the carbonate surface to the organic solvent phase. Moreover, the results of simulated calculation show that the introduction of a functional group with conjugated structures into ionic liquid, such as an imidazole ring and a benzene ring, is beneficial for enhancing oil recovery, which are in accordance with the results of experimental tests.

Highlights

Unconventional oils, with geological reserves of up to about two-thirds of total petroleum, have been considered as a major part of petroleum energy [1]
RReessuullttss iinn FFiigguurree 55 showw all of the one-stage asphalt recoveries of amino acid ionic liquids (AAILs), ranked from 87.85% to 91.26%, are ssignifificantly higher than that oof ttrraaddiittional ttooluene eextraction (77.79%%)), especiiaallllyy ChhHHiiss (Figguurree 55aa)) up to 91.26%
A series of AAILs were synthesized economically using cheap raw materials via a one-pot synthesis, achieving high purity. These AAILs were found to perform well in separating the extra-heavy oil from carbonate asphalt rocks, resulting in better oil quality with fewer solid entrained compared with solvent extraction

Summary

Introduction

Unconventional oils, with geological reserves of up to about two-thirds of total petroleum, have been considered as a major part of petroleum energy [1]. The Indonesian asphalt rocks, one kind of oil sands with bitumen content up to 50 wt.%, was reported to possess over 3 billion tons of bitumen geological in situ reserves. It is proved that the traditional water-flooding process works poorly in separating asphalt from carbonate rocks [4]. To unlock this kind of petroleum ore, other different methods have been proposed, such as solvent extraction [1,5,6,7], ionic liquid-assisted solvent extraction [8,9,10,11], and pyrolysis [12,13,14,15]

Objectives

Results

Conclusion