Innovative Structure of a Liquefied Natural Gas (LNG) Process by Mixed Fluid Cascade Using Solar Renewable Energy, Photovoltaic Panels (PV), and Absorption Refrigeration System

Abstract

Among the principal industrial approaches for conveying natural gas, aside from pipeline transportation, is the liquefaction of natural gas (LNG). In recent years, a significant portion of natural gas imports has been done through the transportation of LNG. The economic viability of an LNG venture is substantially influenced by the pivotal role of the liquefaction procedure in determining its financial returns. Conversely, a paramount concern within LNG plants revolves around enhancing the energy efficiency of the liquefaction procedures. In this research, an Innovative structure of a liquefied natural gas process by mixed fluid cascade using solar renewable energy, photovoltaic panels (PV), and absorption refrigeration system is presented and evaluated. This structure relies on substituting the vapor compression refrigeration cycle with the absorption refrigeration system. The required power of the cycle is 19.37 MW and is provided by renewable solar energy and PV, and the absorption refrigeration system derives its necessary heat load from the existing surplus heat within the facility. Aspen HYSYS V12.1 software, a conventional chemical process simulator, performs process simulation. Also, the design and simulation of PV were performed using the PVsyst 7.3.1 software, with the weather conditions in Rafsanjan City, Kerman Province, in Iran. To supply the part of cycle power, out of 3 modules of AXITEC AC-550MBT and 157 inverters Canadian Solar CS-125KTL have been used. The highest and lowest of performance ratio (PR) were 89.6 % in January and 78.9 % in July, respectively. Also, the highest and lowest of available energy were 3,726.8 in September and 3,304.6 MWh in February, respectively. Additionally, the maximum and minimum losses due to mismatch were recorded in September and February in the amount of 83.79 and 72.77 MWh, respectively. The ammonia-water cycle has a coefficient of performance (COP) at a value of 0.48. As well as the presented innovative structure displays a specific energy consumption (SEC) of 0.172 kWh/kgLNG, illustrating a 30 % decrease in energy usage. Also, the presented novel system offers the potential to achieve a reduction of up to 31 % in the necessary heat transfer area. © 2024 Elsevier B.V.