Process intensification for the retrofit of a multicomponent distillation plant - An industrial case study

Process intensification is currently considered as the main trend to improve process performance, and one of the major approaches to this regard is to reduce the number of pieces of equipment in the plant. For distillation systems, thermal coupling technique provides such an approach to retrofit the traditional simple column configurations through the elimination of the condenser and/or the reboiler. In this work, starting from the existing plant with the simple columns, two types of retrofit alternatives are proposed. The first includes the possible alternatives by eliminating all the condensers and reboilers involving the submixtures. The second includes all the possible alternatives when only some of the condensers and/or reboilers are eliminated at one time. The latter solution represents less modification to the existing plant. In addition, in order to investigate the capital investment for the modified plant, all the obtained alternatives through the recombination of the column sections have been compared. All the configurations were compared with respect to energy saving and the possibilities to reuse the plant equipment. The optimal solution was found to be the alternative that has the minimum modification to the existing plant. At the same time, it achieves a 23% savings on energy consumption and allows a maximum reuse of the pieces of the existing equipment.