Novel integrated CCHP system for generation of liquid methanol, power, cooling and liquid fuels using Kalina power cycle through liquefied natural gas regasification

Abstract

The simultaneous design of units and the integration of processes reduce the number of required equipment and energy consumption. The integrated structures are considered as the most appropriate option for providing the electrical energy demand and energy storage in the remote areas. The growing need of human being to the fuel and decrease in the oil resources have led great attention to be attracted to the natural gas resources and the need of using the methods for converting the gas fuels into liquid fuels and methanol. In this paper, an integrated structure is developed that includes a Kalina power generation cycle through liquefied natural gas regasification operation, a Fischer-Tropsch synthesis, an organic Rankine cycle, an electrolyzer system, and a methanol production cycle. This integrated structure produces 4953.1 kW power, 4.063 kg/s liquid methanol, 3.781 kg/s liquid fuels, and 1823 kW cooling in the energy demand stage. The natural gas produced during the LNG regasification operation is used to produce synthesis gas by the autothermal reforming method. The heat produced by the Fischer-Tropsch reactor was used by applying the water circulation inside the shell to provide a part of the heat required for the methanol production cycle as well as to provide the power in the integrated structure. The total energy and exergy efficiencies were 74.21% and 76.41%, respectively. The sensitivity analysis performed on the system shows that by reducing the recirculation rate of the stream G20 up to 22.5%, the total thermal efficiency increases up to 8.53%.