New approaches to low production cost and low emissions through hybrid MED-TVC+RO desalination system coupled to a gas turbine cycle

Waste heat recovery in a gas turbine cycle for thermal desalination units is a convenient solution to reduce GHG emissions. In this study, multi-effect thermal vapor compression desalination (MED-TVC) and reverse osmosis (RO) plants are integrated with a gas turbine cycle through a recovery steam generator (HRSG) to reuse waste heat. The Thermodynamic, exergy, and thermoeconomic model of each section are developed. Besides, based on the interconnection between input and output streams of MED-TVC + RO, six configurations are proposed. The corresponding results are optimized via the Genetic Algorithm (GA) and compared through two different approaches. The total products in each approach are limited to 105,000, 122,500, and 140,000 m3/day. In the first approach, the MED-TVC plant production is constant (70,000 m3/day). In the second approach, MED-TVC desalination production is assumed to be variable to provide a large portion of total fresh water. The best configuration among six configurations in terms of the lowest production cost at both approaches is related to use the cooling water of MED-TVC as the RO system feed water. Moreover, the results showed that NOx, SO3, SO2, and CO2 decreased to 165.53, 7.33, 783 ppm, and 10.5% of the volume fraction, respectively, by applying GHG analysis. •Reducing the cost of production of hybrid desalination plants is considered.•Based on the interconnection between MED-TVC and RO, six configurations are proposed.•The output stream of one plant (MED-TVC or RO) is used as another plant’s feed water.•The optimal solution of each configuration is presented in two different approaches.•Thermodynamic, thermoeconomic, exergy, and GHG analyses are applied.