Influence of refrigerants on a small-scale liquefied natural gas production process

摘要

An optimized, small-scale liquefied natural gas production process based on nitrogenrefrigerant has been recently proposed by Khan et al (Khan et al. (2015). Knowledge inspired investigation ofselected parameters on energy consumption in nitrogen single and dual expander processes of natural gasliquefaction, Journal of Natural Gas Science and Engineering, 23, 324-337). In the above cited work, bothsingle and dual expander processes were analyzed and findings suggest that the specific energy requirement forthe dual expander process reduced by 33 percent. In this paper, we propose an even more optimized processfollowing a study of the influence of three single refrigerants (nitrogen, methane and argon) and one mixedrefrigerant (argon-methane mixture) on energy savings and LNG productivity. The dual expander processflowsheet originally proposed by Khan et al. and aproprietary process simulation software are used for thepresent study. A comparison of our process with the optimized process earlier proposed by Khan et al (2015)shows significant reduction in energy consumption, with the specific energy requirement further decreasing byover 50 percent.