Energy-saving quaternary extractive distillation processes with single- or double-dividing-wall column for separation of acetone/methanol/butanone/tert-butyl alcohol

This article proposes two energy-saving extractive distillation configurations with single- or double-dividing-wall column, based on a conventional four-column extractive distillation process -CFC-ED, to efficiently separate a quaternary compound of acetone/methanol/butanone/tert-butyl alcohol with chlorobenzene as a solvent. One is composed of two single-dividing-wall extractive distillation columns-SDWCs-ED; the other consists of an extractive distillation column and double-dividing-wall extractive distillation column-DDWC-ED. The parametric optimization is carried out with the minimum total annual cost (TAC) as a goal and adopts a sequential iterative procedure. The comparison with the CFC-ED process shows that the SDWCs-ED process can reduce the TAC by 12.50 % and CO2 emission by 24.23 % while the DDWC-ED process can save the TAC by 11.97 % and CO2 emission by 14.43 %.