Three-Dimensional Sustainability Analysis for Integrated Process Design and Control for Separation of Benzene and Toluene Mixture

The objective of this paper is to present the development of a sustainable integrated process design and control methodology for a distillation column system. The sustainable integrated process design and control methodology for a distillation column system is developed to ensure the distillation column design is more cost efficient, controllable and sustainable to meet the product quality. The sustainable integrated process design and control problem for a distillation column system is typically formulated as a mathematical programming (optimization with constraints) problem, and solved by decomposing it to six sequential hierarchical sub-problems: (i) pre-analysis, (ii) design analysis, (iii) controller design analysis, (iv) sustainability analysis, (v) detailed economics analysis and (vi) final selection and verification. In the pre-analysis sub-problem, the concept of driving force is used to locate the optimal design-control solution targets, which are defined at the maximum point of the driving force diagram. The sustainability analysis sub-problem was calculated by using the three-dimensional sustainability index. The results through case study of benzene-toluene separation process shows the proposed methodology is capable to find the optimal solution that satisfies design, control, sustainability and economic criteria in a simple and efficient way.