Process intensification on the separation of benzene and thiophene by extractive distillation

Abstract

The separation of benzene and trace thiophene by extractive distillation was intensified in two aspects, that is, selection of a suitable entrainer and improvement of the process. The mixture of dimethylformamide (DMF) and an ionic liquid (IL) was chosen as the entrainer. Vapor–liquid equilibrium (VLE) experiments using pure DMF and a mixed entrainer were conducted, and UNIFAC model for ILs was extended to the benzene‐thiophene‐DMF‐IL system. The results demonstrated that volatilization loss of DMF in the vapor phase was significantly reduced by adding IL. Moreover, an improved process with only four columns using a mixed entrainer was proposed. The results indicated that the improved process is more promising for decreasing energy consumption and equipment investment compared with the conventional six‐column process. The total heat duties of reboilers and condensers was decreased by 6.47% and 6.41%, respectively. The process intensification strategy may be directly extended to separate trace components of other systems. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4470–4480, 2015

Effect of cation alkyl chain length on liquid-liquid equilibria of {ionic liquids + thiophene + heptane}: COSMO-RS prediction and experimental verification

“…Moreover, the higher b of [C 6 [29,39]. Overall, COSMO-RS can be employed as a valuable tool to quickly identify the aniondependency of the effect of cation alkyl chain length on the b.…”

“…Because of the ionic characters of ILs, cations are strong HB donors but weak acceptors, and anions are strong HB acceptors but weak donors [28,30]. 6,8) were determined at 298.15 K and ambient pressure to validate the COSMO-RS prediction. Heptane and thiophene were purchased from Aladdin Chemical Co., Ltd. with purity above 99.0 wt%, and no impurities were detected by gas chromatograph.…”

Thermal coupled extractive distillation sequences with three entrainers for the separation of azeotrope isopropyl alcohol + diisopropyl ether

“…Currently, special distillations such as extractive distillation (ED), heterogeneous azeotropic distillation (HAD), pressure‐swing distillation (PSD) and reactive distillation (RD) are adopted to separate such azeotropes. Arifin et al .…”

Dearomatization of pyrolysis gasoline with an ionic liquid mixture: Experimental study and process simulation

“…4,5 ILs have been employed in the extraction of aromatics from alkanes, 6 in the separation of sulfur and nitrogen-based hydrocarbons from gasolines, 7,8 in the recovery of organic compounds from reaction media, 9 in the liquid-liquid extraction of proteins and essential oils, 10,11 and in vapor-liquid separations of hydrocarbons as entrainers. [12][13][14] Specifically in the extraction of aromatics a wide number of ILs had been studied.…”