Energy Integration of Production Systems with Batch Processes in Chemical Engineering

Abstract

AbstractThe integration of energy and mass processes is one of the most powerful tools for creating sustainable and energy efficient production systems. Process integration covers a wide range of system-oriented methods and approaches that are used in the design and reconstruction of industrial processes to obtain optimal use of resources. Traditionally, methods have focused on energy efficiency, but more recently they have also covered other areas, such as the integration of mass processes for the efficient use of water and other resources.In production systems with batch processes, the task of energy integration is significantly more complex due to the presence of predominantly low-potential heat, which until recently was considered not to be recoverable. In addition, the periodic and discrete nature of heat sources and recipients imposes additional constraints that require process coordination. Two main approaches for thermal integration of periodic processes are defined, direct and indirect: Direct heat integration determines the existence of heat exchange between technological flows that occur simultaneously over time. This approach to heat recovery requires adherence to a strict production schedule to ensure energy efficiency and product quality. In the chapter different variants for direct heat integration are considered, with recirculation of the main fluids, or with the use of intermediate heating and cooling agents. The corresponding mathematical models are derived. Indirect heat integration determines the existence of heat exchange between flows that do not occur simultaneously in the system. This approach uses intermediate fluids and a heat storage system (heat tanks) so that the heat can be stored, transferred, and utilized in a future period of time. It allows the heat exchange process to be less limited and less sensitive than schedules and provides some operational flexibility. The possibilities for heat integration with the use of one common cold/hot heat tank and two separate ones, but with a common heating/cooling agent are considered. The respective mathematical models are also presented. Key wordsDirect heat integrationRecirculation main fluidsIntermediate heating and cooling agentsIndirect heat integrationTwo heat storageOne heat storage