Comparative Analysis of the Refrigeration of Natural Gas Using Propane PreCooled Mixed Refrigerant and C1 -C3 Cascade Refrigerant

Abstract

The liquefied natural gas remains the most viable means of global distribution of natural gas. Unfortunately, the liquefying process consumes high amount of energy impacting negatively on the economic viability of the LNG business. Based on this, the current work assesses the selection of propane pre-cooled mixed refrigerant [C3 MR] and methane, ethane and propane [C1 -C3 ] refrigerant cascade system as a refrigerant with essential benefits in LNG production. The process was simulated using Aspen HYSYS, and its economic tool was used to carry out the techno economic analysis and estimate the duties of the two processes. The results obtained showed that the production cost were $20,345,490 and $114,796,200 for C1 -C3 cascade refrigeration system and C3 MR, respectively. The duty were 568.721 MW and 626.462 MW for the C1 -C3 cascade refrigeration system and C3MR, respectively. This shows that C1 -C3 cascade refrigeration system performed better than the C3 MR. Therefore, the former refrigerant is preferred in a liquefying process than the latter as it is cheaper, consumes less amount of energy and is more environmentally friendly.