1‐Butyl‐3‐methylimidazolium chloride involved in sequential extraction of lignite to separate group components and its effect on functional groups of residues

Abstract

BACKGROUND: In view of the low economic benefit for direct utilization of lignite, the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) has been used to extract Inner Mongolia lignite (IML) in order to efficiently separate lignite, develop the technology for clean and value-added utilization of lignite, and alleviate the enormous pressure of ecological environment pollution. Subsequently, sequential extraction of IML by [Bmim]Cl/N-methyl-2-pyrrolidone (NMP), acetonitrile and ether was employed to separate group components in lignite. RESULTS: Functional group results show that hydrogen bonds of IML including OH ether, COOH dimers and SH N, and weak covalent bonds such as C al O, C al N, C al S and S S, can be cleaved by [Bmim]Cl. Extraction experiments using mixed solvents of [Bmim]Cl and NMP or water indicate that the synergistic effect of NMP and [Bmim]Cl plays a vital role in increasing lignite extraction yield, but for water an opposite effect is observed. Importantly, the group components extracted by [Bmim]Cl/ NMP and consecutively by acetonitrile and ether show a clear difference in composition according to gas chromatographymass spectrometry. Specifically, polycyclic aromatic hydrocarbons and long-chain alkanes are present in the acetonitrile phase, with relative content of 8% and 88%, respectively, while most of esters, aliphatic acids and phenols are dissolved in ether with proportions of 35.24%, 35.53% and 16.57%, respectively. CONCLUSION: This work demonstrates that sequential extraction of lignite by [Bmim]Cl/NMP, acetonitrile and ether may provide new insights for the separation of group components and clean utilization of lignite in industry.

Hydroisomerization Principles of Acenaphthene to Alkyladamantanes over Modified USY-Supported Pt Catalysts

“…The extraction of high value-added chemicals from coal could not only meet the growing demand for energy and resources but also alleviate the huge pressure of ecological and environmental pollution . Therefore, how to efficiently extract high value-added products from coal carbon has received widespread attention.…”