Search

Benzene, Toluene, and Xylene (BTX isomers) are significantly vital fundamental chemicals for petrochemical, oil, and gas industries with global production amounting to about 40 MMT per annum for Benzene and Xylene while around 20 MMT for toluene. BTX as initiators for downstream derived commodities are produced from coking and petroleum naphtha and pyrolysis gasoline by hydro-treatment and catalytic reforming processes. The present work focuses on ASPEN simulation for BTX separation via conventional distillation and extractive distillation routes. For the extractive distillation (ED) process, two different solvents – Dimethyl Sulfoxide (DMSO) and Sulfolane were employed to estimate the purity of separated components from the mixture as well as the recovery percentage of solvent for reuse potential. Extractive distillation processes are widely adopted for isolating aromatic and non-aromatic hydrocarbons. Solvents employed in ED typically aid in separation due to close boiling points and azeotropic compositions of mixtures. Maximum purity of components at 97.91 % Benzene, 98.27 %Toluene, and 96.88% o-Xylene were obtained after separation with 98.33% solvent recovery using sulfolane as solvent. Amongst various dipolar aprotic solvents like DMF, DMAC, NMP, and DMSO, sulfolane is also known to offer appreciable thermal stability. Sulfolane also possesses attractive properties such as high selectivity, high boiling point, and high dissolution capability. [ABSTRACT FROM AUTHOR]

A waste solvent mixture of acetone-methanol in a pharmaceutical plant which is minimum-boiling azeotrope properties, it is difficult tasked to separate this liquid mixtures by conventional batch distillation. To achieve higher purity, a batch extractive distillation, combining the extraction and separation into a single stage, is widely carried out to separate this waste solvent mixture. The objective of this work is to study an approach to produce acetone with the purity of 94.0% by mole by a batch extractive distillation column. In the column operation, semi-continues mode has been proposed to improve purity of acetone. The total reflux start-up period is finished when the unit reaches its steady state and/or maximum purity. Water has been used as solvent. Dynamic optimization strategy is proposed after the total reflux start-up period is ended. The optimization problem is formulated to maximize the weight of distillate product for a given product specification, reboiler heat duty, and batch operating time. Simulation results show that 94.0% purity of the distillate product can be produced by the dynamic optimization programming with two or more time intervals. Besides, the higher time intervals results in the higher distillate product. [ABSTRACT FROM AUTHOR]

This paper introduced extractive distillation to overcome the drawbacks of conventional distillation in separating dimethyldichlorosilane and methyltrichlorosilane. Based on the prediction of UNIFAC model, this paper adopted vapor-liquid equilibrium experiment for the entrainer selection. Aspen plus was employed to simulate the extractive distillation process to determine the overall energy consumption and separation effect. Simulation results showed that extractive distillation of dimethyldichlorosilane and methyltrichlorosilane was industrially feasible. [ABSTRACT FROM PUBLISHER]