Synthesis of heat integrated resource conservation networks

Abstract

Huge amount of energy and fresh resources (i.e. water, chemicals, solvents) are consumed by process industries to achieve the desired product throughput and quality. The current drive toward sustainability and business competitiveness has driven the process industries to effectively use these resources. Thus, resource conservation activities have become the centre of attention as compared to conventional end-of-pipe waste treatment system. Process integration has been commonly used as an effective tool for resource conservation and waste reduction. One of the most established areas of process integration is concentration- and property-based resource conservation networks (RCNs). Most works in RCNs synthesis do not consider temperature as part of process constraints. However, in many cases, temperature is an important design parameter. Thus, simultaneous consideration of mass/property and heat recovery should be addressed. Earlier works in this area have been mainly focusing on heat integrated water networks (HIWNs).However, these methods cannot be applied for property-based RCNs, as they are limited to “chemo-centric” system. Clearly, a more generic approach is needed for the synthesis of concentration- and property-based heat integrated resource conservation networks (HIRCNs). This thesis presents novel and generic methodologies for the synthesis of concentration- and property-based HIRCNs with variable operating parameters (i.e. flowrates, temperatures and properties). Firstly, a new generic overall methodology for concentration- and property-based HIRCNs is established. Next, a general framework for synthesis of HIRCNs with and without heat of mixing is presented. Based on this framework, new methodology for the synthesis of HIRCNs with and without heat of mixing are established respectively. Moreover, a revised floating pinch method is developed for utilities targeting in heat exchanger networks (HENs) with varying temperature range, and it is incorporated in the new methodologies for the synthesis of HIRCNs with and without heat of mixing. Various case studies are solved to illustrate the developed methodologies.