Extractive distillation of benzene, toluene, and xylenes from pyrolysis gasoline using methylsulfonylethane as a cosolvent

Abstract

Highly efficient separation of benzene, toluene, and xylenes (BTXs) from pyrolysis gasoline is very important in petrochemical industries. Though the extractive distillation (ED) process is simpler and consumes less energy compared with liquid–liquid extraction process, it is difficult for a single solvent, for example, sulfolane, to achieve both high purity and high yield of BTXs. In this work, methylsulfonylethane (MSE) was chosen as a cosolvent to improve the selectivity of sulfolane after solvent screening, and factors that may affect the selectivity of the composite solvent were fully investigated, such as the content of cosolvent, solvent to feed ratio, the composition of the feed, and temperature. Furthermore, 240 h of continuous extractive distillation and solvent recovery experiment was carried out using sulfolane (85 wt%)–MES (15 wt%) mixture as solvent. The purity of mixed aromatics obtained was 99.83%, and the yield was as high as 99.7%.

Evaluation of hybrid solvents featuring choline chloride-based deep eutectic solvents and ethanol as extractants for the liquid–liquid extraction of benzene from n-hexane: towards a green and sustainable paradigm

“…On the other hand, transport property such as viscosity fixes the hydrodynamics, mixing and flow issues. In the petrochemical industries, aromatic production from various sources like pyrolysis gasoline, reformate or naphtha accounts for 40 million metric tons of benzene, 40 million metric tons of xylenes and 20 million metric tons of toluene per annum globally [ 2 ]. A critical stage of this production process is the liquid–liquid extraction of the aromatics from the non-aromatic (or aliphatic) media.…”