US patent US12742589
Closed loop LNG process for a feed gas with nitrogen
Abstract
Systems and methods for processing liquefied natural gas (LNG) can include an LNG production system with a methane refrigeration cycle downstream from an ethylene refrigeration cycle. The methane refrigeration cycle can be a closed loop methane refrigeration cycle that maintains a methane refrigerant separate from a natural gas feed, (e.g., compared to an open loop methane refrigeration cycle that extracts the methane refrigerant from the natural gas feed and recombines the methane refrigerant with the natural gas feed). The natural gas feed can be a medium or high nitrogen gas feed having a nitrogen content greater than 1.0% molarity.