(636e) Energy Optimization through Process Integration in Multipurpose Batch Plants: Intermittent Continuous Streams

Batch processes are a common encounter in the manufacture of small volume high value added products. In most of these processes, common equipment is shared among various products thereby necessitating the need for scheduling in order to meet production demands. In the past, very little work has been done in reducing energy demand in such operations due to the perception that they inherently consume less energy compared to their continuous counterparts. However, this has changed drastically in the last decade as most production facilities adopt the batch mode of operation due to its adaptability to fluctuating market conditions, hence the need for dedicated energy reduction techniques. In this paper, a mathematical technique for heat integration in multipurpose batch plants is presented. The uniqueness of the problem addressed stems from the consideration of continuous streams that transfer intermediates from one batch unit operation to another. In the context of this work, these streams require heating and cooling and are only active intermittently for short durations during the time horizon of interest. The consideration of these streams takes place within an overall scheduling framework. A typical case study is presented to demonstrate the efficacy of the developed technique.