Despite generating enormous interest,
the full landscape of process
intensification and multiobjective optimization (MOO) remains unexplored
in the area of batch extractive distillation (BED). This paper is
focused on articulating a mixed-integer nonlinear MOO problem to optimize
both conventional and vapor recompressed BED, considering both existing
and new plant scenarios. Process optimization of BED columns typically
involves several technical, economic, and environmental objectives
that are conflicting in nature, which lead to many equally good optimal
solutions from the perspective of the given objectives. Here, the
objective functions considered for BED optimization are minimization
of total annual cost and CO2 emissions along with maximization
of total annual production of two components that form an azeotropic
mixture. To perform this optimization, a unique MOO strategy is adopted,
which comprises of three steps. The first step deals with the selection
of significant decision variables through Taguchi analysis followed
by the formulation of the optimization problem. In the second step,
BED is optimized with the help of an elitist nondominated sorting
genetic algorithm. The third step comprises of a selection of a solution
from the Pareto-optimal front using the TOPSIS (Technique for Order
of Preference by Similarity to Ideal Solution) with entropy information
for weighting of objectives. The performance of this MOO strategy
for BED optimization without and with vapor recompression is illustrated
for the separation of acetone–methanol mixture with water as
the homogeneous entrainer. Finally, a comprehensive analysis is performed
to assess the superiority of vapor recompressed BED over conventional
BED.