Integration of Renewable Energy into Mass, Heat and Regeneration Network Synthesis

This paper presents a new synthesis method for optimally integrating mass exchange networks, involving regeneration, with solar thermal energy, so as to reduce the quantity of water used in mass exchange operations, while simultaneously reducing the environmental impact associated with the use of fossil based energy sources. The problem in this paper involves gaseous streams from which ammonia has to be removed using water as the mass separating agent. The ammonia rich lean stream is then sent to a regenerator where steam stripping is used to remove the ammonia, after which the lean stream, which is now somewhat free of ammonia, is recycled back to the network of mass absorbers for further ammonia absorption from the gaseous streams. The stage-wise superstructure is adopted, however it is extended by including models to account for primary mass exchange, regeneration and heat exchange subnetworks. Other extensions include the addition of model equations to determine optimal solar panel area and heat storage vessels. The example considered demonstrates the benefits of the integrated approach.