Indirect thermal integration for batch processes

•Algorithms to target minimum utility requirements for single as well as cyclic batch process are proposed.•The proposed methodology accounts for indirect thermal integration between various different time intervals.•The proposed methodology overcomes the limitations of existing methodologies.•The proposed methodology guarantees the optimality as it is proved using rigorous mathematical arguments.

Rigorous algorithms to target the minimum utility requirements for single as well as cyclic batch processes are proposed in this paper. Practically, heat integration between two different time intervals requires indirect integration through intermediate fluid. Targets, calculated via proposed methodology, account for indirect thermal integration in batch process. The proposed methodology overcomes limitations of existing methodologies and guarantees the optimality as it is proved to be optimum using rigorous mathematical arguments. This methodology is applicable to any fixed-scheduled batch process. Applicability of the proposed methodology is demonstrated through illustrative examples. In one of the illustrative examples, a reduction of 18.7% and 16.4% (in comparison to time slice model) is observed in hot and cold utility requirements, respectively.