Ionic liquid [BMIm][HSO4] as dual catalyst-solvent for the esterification of hexanoic acid with n-butanol

Brønsted acidic ionic liquids (BAILs) with great variety as effective catalysts for the synthesis of valuable chemicals such as esters have attracted particular attention. In this work, an ionic acid 2-hydroxyethylammonium bisulfate (2-HEAS) was successfully synthesized and used to catalyze esterification reactions. The powerful FTIR and NMR techniques were used to determine the ionic liquid properties. All results and data showed that the ionic liquid has been synthesized successfully. The catalytic activity of IL during esterification of acetic acid in the presence of various alcohols was investigated. The impacts of a few imperative parameters such as reaction time and temperature, molar ratio of acid to alcohol, and catalyst dosage were investigated. The results showed that the 2-HEAS catalyst is suitable for esterification of methanol, ethanol, and butanol. Furthermore, the esterification efficiencies of methyl acetate, ethyl acetate, and butyl acetate produced were high and quantitative. Moreover, a homogeneous catalyst was employed to separate esters from the reaction medium. Additionally, the catalyst was easily removed from products and was reusable six times.

Section: Resultsmentioning

confidence: 94%

2-Hydroxyethylammonium Bisulfate (2-HEAS) as a Brønsted Acidic Ionic Liquid Catalyst for Esterification

Shahbazi

Tavakoli

Hosseini

et al. 2022

“…ILs are generally known as molten salts with melting points around room temperature. They have been featured as a neoteric solvent platform in the domain of chemical separation owing to their exceptional properties such as negligible vapor pressure, high thermal and chemical stability, and designable character. − Particularly, for absorption processes, ILs are conceived as promising absorbents due to the fact that they have no residues in gas product, easy regeneration by simple distillation, and high selectivity given a suitable cation–anion combination. − With respect to the solubility of fluorinated refrigerants in ILs, a lot of studies have been conducted in literature studies. − A more recent review elaborated by Asensio-Delgado et al has compiled equilibrium data and modeling efforts from near 200 published articles . In this excellent work, more than 5000 data points are collected and comprehensively analyzed, which provides a useful source of data for theoretical predictions of refrigerant-in-IL solubility.…”

Section: Introductionmentioning

confidence: 99%

Hierarchical Ionic Liquid Screening Integrating COSMO-RS and Aspen Plus for Selective Recovery of Hydrofluorocarbons and Hydrofluoroolefins from a Refrigerant Blend

Qin

Cheng

Hantao

et al. 2022

Self Cite

The selective recovery of hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) from end-of-life equipment is regarded as an efficient and sustainable way for their reclamation, thereby reducing the production and emission of HFCs with high global warming potential. A R454C blend constituted of difluoromethane (R-32) and 2,3,3,3-tetrafluoropropene (R-1234yf) is a nontoxic and mildly flammable refrigerant ideally suitable for hermetically sealed refrigeration systems. This work presents a hierarchical screening of ionic liquids (ILs) for R-32 and R-1234yf recovery from R454C. First, 1093 HFC/HFO-in-IL solubility data (543 for R-32 and 550 for R-1234yf) are collected from the literature to evaluate the reliability of the COSMO-RS model for this system. Then, the solubility of R-32 and R-1234yf in 2224 ILs composed of 59 cations and 38 anions is predicted by COSMO-RS; following that, the IL structural effects on gas solubility are analyzed according to σ-profiles and excess energies. Subsequently, combining the thermodynamic performance and the melting point constraint, the top six ILs among the involved ILs are identified. Based on the retained ILs, a continuous absorption is simulated and evaluated in Aspen Plus, demonstrating that ILs n-(3sulfopropyl)pyridinium thiocyanate and n-(3-sulfopropyl)pyridinium hydrogensulfate are promising absorbents from the process point of view.

“…Reactive distillation (RD) is a multiple-unit operation that combines the reaction and distillation processes, which utilizes the advantage of reaction product separation and phase splitting for online removal of products from the reaction system. RD can break the limitation of chemical equilibrium, thus enhancing the conversion of reactants . Moreover, RD can significantly reduce process and mechanical operation cost, , and hence, it has been widely applied in many fields of chemical engineering. , However, using ILs to catalyze the esterification in the RD process has been rarely reported.…”

Section: Introductionmentioning

confidence: 99%

“…RD can break the limitation of chemical equilibrium, thus enhancing the conversion of reactants. 26 Moreover, RD can significantly reduce process and mechanical operation cost, 27,28 and hence, it has been widely applied in many fields of chemical engineering. 29,30 However, using ILs to catalyze the esterification in the RD process has been rarely reported.…”

Section: Introductionmentioning

confidence: 99%

Study on the Intensification of Reaction Kinetics and Reactive Distillation for the Esterification of N-Butyl Acetate Using [HSO₃-BMIM][HSO₄] as a High-Efficiency Ionic Liquid Catalyst

Zhang

Muhammad

et al. 2021

An ionic liquid (IL) catalyst 1-sulfobutyl-3-methylimidazolium hydrogen sulfate, [HSO 3 -BMIM][HSO 4 ], was used to produce nbutyl acetate (BuAc) via esterification. A novel modified nonideal homogeneous kinetic model was developed by self-catalysis theory. A new reactive distillation (RD) process using [HSO 3 -BMIM][HSO 4 ] to produce BuAc was intensified using Aspen simulation taking advantage of phase splitting to increase the ester purity. Various design parameters like reactant feed location, reflux ratio, reactant feed molar ratio, flow ratio of products to materials, and condenser pressure were optimized. Fitting results indicated that modified models presented exact prediction results for the [HSO 3 -BMIM][HSO 4 ]-catalyzed esterification compared with the unmodified model because the former introduced a revisional term for the self-catalysis of HAc, which revealed the mechanism of self-catalysis and interaction between ILs and reactants. The BuAc purity was increased from 91.05 to 95.02 wt % by the RD process intensification. [HSO 3 -BMIM][HSO 4 ] showed a higher acid conversion (75%) than commercial ILs and resins. The ester yield was higher when using [HSO 3 -BMIM][HSO 4 ] as the catalyst than resin A (80.89 wt %) in the intensified RD process. This research provides a novel modified method for the kinetic model in the IL-catalyzed reaction where the modified model exhibited a high accuracy and is useful for improving the production efficiency and controlling the catalyst dosage in the chemical engineering process design. The intensified RD process shows a flexible design for IL application, which is helpful for designing industrial scale-up.