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A novel synthesis framework is presentedfor evaluating differentconfigurations and sequences of batch distillation processes and identifyingthe most appropriate flowsheet and cost-effective operating conditionssimultaneously. A superstructure for batch distillation systems isconstructed by employing a generic unit, which consists of segmentsof trays with top and bottom vessels attached to it, and accommodatingthree different types of integrated network design options for feedconnections, sequencing connections, and configuration connections.This systematic formulation of batch distillation sequencing designproblems allows not only the optimization of conventional flowsheets,but also the generation of novel configurations and sequences. Theoptimization framework is based on an mixed-integer nonlinear programming(MINLP) problem, which is effectively solved with a hybrid optimizationmethod using simulated annealing and sequential quadratic programming(SA-SQP). Case studies are presented to demonstrate how the proposedapproach can be applied in practice to improve cost-effectivenessof batch distillation systems. [ABSTRACT FROM AUTHOR]

Techno-economic analysis has been carried out for a single-stepnoncatalytic esterification process which produces biodiesel frompalm fatty acid distillate (PFAD). A simulation model for this biodieselproduction process has been developed, which provided the basis forthe estimation of capital expenditure and operating cost. Althoughthe process considered in this work has been observed as nonprofitableeven at considerably large-plant capacity, the net cash flow becomessurplus at the capacity of 100 kt·y–1. Effectsof raw material cost and biodiesel product price on the economic feasibilityof the process have also been evaluated. With techno-economic analysis,it was found that the current biodiesel process would be economicallyviable with favorable changes in the economic parameters, i.e. $50·t–1reduction for raw material purchasecost or $50·t–1increase forbiodiesel sales price. [ABSTRACT FROM AUTHOR]

The optimal operation of batch distillation systems hasbeen studiedin this paper. A new approach termed the limiting gradient approachis introduced for effectively identifying feasible and cost-effectiveoperating profiles for batch distillation systems. A new semirigorousmodel for batch distillation has been presented for considering holdupof the column, which is applicable for different batch distillationconfigurations. A novel optimization model incorporating the limitinggradient approach has been proposed, which significantly reduces computationalburden to search for a feasible operation of a batch distillationcolumn by considerably reducing effort for carrying out a large numberof dynamic simulations required for optimization. Case studies havebeen presented to demonstrate the applicability of the approach forvarious batch distillation configurations and to illustrate how theproposed optimization framework systematically addresses differentperformance indices and objectives. [ABSTRACT FROM AUTHOR]