Integration of Desalination Systems to Low Grade Heat Source in Site Utility

Abstract

Conventional desalination technologies are energy intensive and if the required energy hails from fossil fuel source, then the freshwater production will contribute to carbon dioxide emission and consequently global warming. Low grade heat source can be very useful to provide energy to the heat sink by upgrading low-grade energy (e.g. low pressure steam). The upgrade of low grade heat can be carried out by desalination technologies by recovering waste heat from various sources. The steam network of site utility system has a suitable potential for production of low grade heat. In this paper, evaluation of coupling different desalination systems which includes multi-stage flash (MSF), multiple effect distillation (MED), membrane reverse osmosis (RO), and hybrid (MSF/MED-RO) to steam network of site utility system with fixed heat supply have been considered. The integration of desalination systems to a low grade heat source has been evaluated using total site analysis and exergoeconomic analysis. In this regard, the computer code has been developed. A steam network of process utility system has been considered as a case study.