Because of limited fuel reserves, increasing prices of oil and growing concerns about the environment, natural gases are receiving attention as low-carbon, eco-friendly fuels. Natural gases have very large gas-to-liquid volume ratio, so the liquefaction process is essential to reduce volume of natural gases. Through the liquefaction process, natural gas becomes liquefied natural gas (LNG). LNG has a comparative advantage in terms of transport and safety. There are several kinds of natural gas liquefaction process. Among the liquefaction processes, propane pre-cooled mixed refrigerant (C3MR) process is the most widely used natural gas liquefaction process to date.
In this study, a steady-state simulation of the C3MR process was performed using ASPEN HYSYS™ and it was optimized to reduce energy consumption. Optimization formulation is developed to minimize operating cost of the process. Optimization variables are temperature, pressure, and flow-rate of refrigerant and composition of the mixed refrigerant.
This research was supported by a grant from the LNG Plant R&D Center funded by the Ministry of Land, Transportation and Maritime Affairs (MLTM) of the Korean government.