Feasibility of a desalination plant coupled with a mini gas turbine combined cycle

Nowadays a large number of desalination technologies are available and widely employed, but most of them require high-energy consumption (in various forms) and high capital and operating costs. Based on the specific characteristic of the desalination process and the requirements for the final product, it is necessary to select the most appropriate desalination technology in order to save costs and energy. In this work, the possibility of coupling a combined cycle of about 2 MW, composed by a simple Brayton cycle (topping) and a Hirn cycle (bottoming) with desalination plants (DP) is analysed. Several components combinations, i.e. gas turbine (GT) and steam turbine (ST), are evaluated, in order to provide two opposite solution: one, able to maximizing the electrical energy production, the other, able to maximizing the thermal energy production. The technical and economic indicators of considered energy desalination systems are evaluated and compared, considering several desalination technologies: MED (Multi-Effect Distillation), MSF (Multi-Stage Flash Distillation), RO (reversed osmosis) and hybrid technologies (MED+RO; MSF+RO). For each considered solution, the fresh water productions and costs are computed and compared in order to evaluate the solution able to better fit the economic and technical requirements.