ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Separation of acetic acid and ethanol from wastewater by distillation process with addition of side draw stream

Badra Mahida, Malika Medjahdi, Ikram Khelifa, Samiha Mazouzi, and Houaria Maghdouri

Laboratory of Process Engineering, Materials and Environment LGPME, Sidi Bel Abbes, Algeria

E-mail: badramahida@gmail.com

Received: 4 May 2022  Accepted: 22 September 2022

Abstract:

This work is a study of the design of a process for the separation of aqueous mixtures containing ethanol (Etha) and acetic acid (AcA) by distillation processes. The process developed for the separation of three cases of high water (W) composition mixtures was simulated by the Aspen Plus V10 software. They regressed the binary interaction parameters of the NRTL model from the existing experimental results. The process comprises three successive columns, the first distillation column with 36 stages where the acetic acid is recovered at the bottom of the column at 99.9% molar. The distillate stream got at the top of this column feeds the second extractive distillation column with 32 stages in the presence of ethylene glycol (Ethy) to separate ethanol with a purity higher than 99.20% mol. At the top of this extractive distillation column and then the bottom stream of this extractive distillation column feeds the third regeneration column with 18 stages to recover ethylene glycol at the bottom with a purity of 99.99% molar which is recycled to the second column with a make-up of 0.37%. Side draw stream is added to stage 4 of the first distillation column. The side draw allows a reduction in energy consumption of 22% compared to a distillation process without a side draw for a feed containing 10% molar acetic acid, 35% molar ethanol, and 55% molar water.

Keywords: Separation of acetic acid–ethanol–water mixture; Extractive distillation; Regression of NRTL parameters

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02516-2

Chemical Papers 77 (2) 837–846 (2023)