Deciphering the Sustainability of an Ionic Liquid-Based BTX Harvesting Process from Energetic, Environmental, and Economic Perspectives

Abstract

1-Ethyl-3-methylimidazolium bis­[(trifluoromethyl)­sulfonyl]­imide ([EMIM]­[Tf2N]) ionic liquid as a novel absorbent has excellent performance in BTX absorption. However, compared with the traditional method using triethylene glycol (TEG), the sustainability of the former is unknown. Thus, to bridge the gap and give a comprehensive evaluation of its industrialization potential, a methodology-integrated energetic, economic, and environmental assessment was employed. The assessment results show that the heating and cooling energy consumptions of the TEG process are 1.08 and 0.74 times higher than those of the [EMIM]­[Tf2N] process, respectively. But through heat integration, 5% hot and 3.4% cold utilities can be saved for the [EMIM]­[Tf2N] process. In terms of economic performance, the total annual costs for TEG and [EMIM]­[Tf2N] processes are 0.6111 and 0.4841 M$/year, respectively, and the latter is 26.3% lower than the former. As for the environmental assessment, the results indicated that compared with the TEG scenario, the [EMIM]­[Tf2N] scenario without absorbent recovery presented higher environmental burdens in all categories, and the largest difference lies in acidification, for which the latter is 42 times that of the former. However, when considering the absorbent recovery, the results are contradictory. Thus, the comprehensive assessment methodology proved that the [EMIM]­[Tf2N]-based BTX absorption process is sustainable and can be a potential industrialization technology.

Experiment and Molecular Mechanism of Two Chlorinated Volatile Organic Compounds in Ionic Liquids

“…The drawbacks of using traditional organic solvents as the absorbents are that there will be volatilization in the process of absorption and solvent recovery, resulting in environmental pollution and absorbent loss. 19 ILs, liquid molten salts, have negligible volatility, flexible designability, and chemical stability, 20,21 and they are widely applied to capture VOCs such as benzene, 22 toluene, 23 dimethoxyethane, 24 ethyl acetate, 25 and acetone. 26 ILs may be potential excellent absorbers for capturing CVOCs, but only a few studies have applied ILs to capture CVOCs.…”

“…ILs, liquid molten salts, have negligible volatility, flexible designability, and chemical stability, , and they are widely applied to capture VOCs such as benzene, toluene, 1,2-dimethoxyethane, ethyl acetate, and acetone . ILs may be potential excellent absorbers for capturing CVOCs, but only a few studies have applied ILs to capture CVOCs.…”

Aromatic volatile organic compounds absorption with phenyl‐based deep eutectic solvents: A molecular thermodynamics and dynamics study

“…However, in the synthesis process, the more complex synthesis steps of ILs, and the purification process with higher energy and material consumption lead to higher production costs when compared with conventional solvents, at the same time, the former have worse environmental impact compared to the latter. Therefore, this limits the large‐scale application of ILs in VOCs absorption 38,39 …”

“…Therefore, this limits the large-scale application of ILs in VOCs absorption. 38,39 Deep eutectic solvents (DESs) are a new type of eutectic mixed solvents formed by the complexation of hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). 40 DESs are similar with ILs in many properties such as negligible volatility, wide liquid range, high electrical conductivity, low surface tension and high solubility to organics and inorganics and so forth.…”

Highly selective extraction of aromatics from aliphatics using an N‐methylpyrrolidone‐based protic ionic liquid

“…Aromatics are key basic materials in the petrochemical industry [ 1 ] that are widely used to produce fibres, plastics, and rubbers. They are typically abundant in oil alongside aliphatics like alkanes and cycloalkanes.…”