Exergetic and economic evaluation of carbon dioxide liquefaction process in a hybridized system of water desalination, power generation, and liquefied natural gas regasification

•Integrated oxy-fuel power plant, air separation unit and water desalination.•Re-gasification operation for cooling source of the organic Rankine cycle is used.•System produced 309.1 MW power, 17.36 kg/s water and 88.4 kg/s liquid carbon dioxide.•Total energy and exergy efficiencies of the hybrid system were 74.19% and 91.73%.•The prime cost of product and return period were obtained 0.148 $/kWh and 3.1 years. In the past, water and energy crises were resolved with fossil fuels and groundwater resources. Nowadays, several research and engineering activities are focusing on combined design of the units and integrated processes due to reduction of underground resources and increased carbon dioxide emissions. In this paper, an integrated structure is developed that includes a cryogenic air separation unit, an organic Rankine cycle (ORC), a liquefied natural gas (LNG) regasification, an oxy-fuel power plant, and a multi effect distillation or desalination (MED). This integrated process produces 309.1 MW power, 17.36 kg/s fresh water, and 88.4 kg/s liquid carbon dioxide. A heat recovery operation on the heat produced from the oxy-fuel power plant is performed to provide the heat required for the ORC, MED unit, and regasification system. In the integrated structure, the total thermal energy and exergy efficiencies are 74.19% and 91.73%, respectively. The exergy analysis of the integrated system reveals that the highest exergy destruction occurs in the reactors with a magnitude of 57.30%, followed by the heat exchanger (14.97%). It is also found that the total thermal energy and exergy efficiencies of the developed integrated configuration are 11.71% and 33.17% higher than those of similar structures reported in the literature. Using the annualized cost method, the economic analysis shows that the investment return period and the prime cost of product are equal to 3.186 years and 0.1480 US$/kWh, respectively. A systematic sensitivity analysis is then conducted to optimize the design and operation of the integrated system. This research work offers useful theoretical and practical tips/guidelines to develop an optimal hybridized process for power generation, carbon dioxide capture, and fresh water production.