Modified Galileo self-refrigerated liquefaction process for economical heavy hydrocarbon removal during gas liquefaction

Effective removal of heavy hydrocarbons prior to liquefaction processes has attracted attention. The purpose of this study was to introduce a modified version of Galileo self-refrigerated liquefaction process and to investigate economical removal of C5+ components under lean feed conditions. A separation section, composed of a two-phase separator and a self-refrigerated exchanger is integrated with the main Galileo process to remove C5+ hydrocarbons from feed gas. This play a complementary role for Galileo ZPTS® conditioning unit for removing non-hydrocarbon impurities. The simulation results showed acceptable removal for C5+ hydrocarbons from feed gas with different compositions before LNG (Liquefied Natural Gas) production. However, for modified process the overall specific power consumed increased (0.628–0.692 kW/kg LNG) for 10% compared with the original process. The modified process was economically compared with adsorption method for heavy hydrocarbon removal and results indicated new scheme can separate heavy components with 56% lower purchased costs and 9% lower total annualized cost compared with an adsorption system. Exergy analysis was also conducted and result showed 11% increase (351.46–392.25 kW) in total exergy destruction of the proposed scheme, however overall exergetic performance of both structures were almost the same.