Thermo-economic analysis of a novel integrated structure for liquefied natural gas production using photovoltaic panels

Abstract

As natural gas is not uniformly distributed in different regions of the world, and gas tanks are concentrated in specific geographical areas, gas transfer is a key gas-related industry that greatly contributes to the expansion of this energy carrier's use. For long distances, the use of pipeline transport is uneconomical in practice, and alternative methods should be adopted. From among alternative methods to pipeline transport, natural gas liquefaction is the best and most economic one. A major challenge to the expansion of liquefied natural gas (LNG) use is the energy-consuming process of its production. The liquid gas production process, like other liquefaction processes, consumes considerable amounts of energy. In this paper, a solar energy and natural gas storage method was developed for transfer to far-away regions for demand response by using the DMR compression refrigeration cycle, Kalina power production cycle, and photovoltaic solar panels for the climate of Chabahar coastal city in Southern Iran. The dissipated heat from the DMR compression refrigeration cycle was used as the heat source for the Kalina cycle. The coefficient of performance, specific energy consumption, and exergy yield of the developed integrated structure were 3.201, 0.2293 kWh kg−1 LNG, and 42.77%, respectively. The exergy analysis of this integrated structure showed that the largest shares of exergy destruction belonged to solar panels (86.29%) and heat exchangers (6.51%), respectively. The economic analysis of the integrated structure revealed that the payback period, the prime cost of product, and additive value equaled 2.061 years, 0.2500 US$ kg−1 LNG, and 0.1156 US$ kg−1 LNG, respectively. The results of sensitivity analysis demonstrated that, for the capital cost of 2100 MMUS$ and less, the payback period is < 4 years.