Improving the power generation efficiency with the use of LNG as cold source by thermoelectric generators for hydrogen production

Abstract

In this study, thermodynamic simulation is developed to strengthening power generation efficiency utilizing liquefied natural gas (LNG) cold source by thermoelectric generators (TGs) for hydrogen production. Firstly, an organic Rankine cycle (ORC) is specified to use the cold energy of the LNG. Then, the cycle is simulated and the results are validated against the available research study data. Afterward, six locations are suggested to install the TGs and the effects of each of these locations on the cycle performance are evaluated. In addition, the economic evaluation of the selected system is done based on annual cash flow, levelized cost and payback time. The results indicate that the highest enhancement in thermal efficiency (TE) is related to Case “d” which the TG added between the seawater and LNG line. The results show that the TE will become 6.876% if the 80% output heat from the seawater enters the TG for the proposed system. From the results: by increasing the γcond and γevap, the values of thermal efficiency, hydrogen production rate and Wnet/WTEG decrease. The economic analysis represented that the payback time for added TG modules with 1 $/W price for TG is 1.29 years.