A natural gas pretreatment system includes a heat exchanger having a first inlet, a second inlet, a first outlet, and a second outlet. The first inlet receives a first pressurized gas stream having a first input temperature, and the second inlet receives a second pressurized gas stream having a second temperature. The second temperature is higher than the first temperature. The first outlet outputs the first gas stream; upon exiting the heat exchanger, the first gas stream has a first output temperature higher than the first input temperature. The second outlet outputs the second gas stream; upon exiting the heat exchanger, the second gas stream has a second output temperature lower than the second input temperature. The system further includes a pipeline network operable to receive the first pressurized gas stream.

A method is disclosed for start-up of a system for liquefying a feed gas stream comprising natural gas. The system has a feed gas compression and expansion loop, and a refrigerant system comprising a primary cooling loop and a sub-cooling loop. The feed gas compression and expansion loop is started up. The refrigerant system is pressurized. Circulation in the primary cooling loop is started and established. Circulation in the sub-cooling loop is started and established. A flow rate of the feed gas stream and circulation rates of the primary cooling loop and the sub-cooling loop are ramped up.

A method is disclosed for start-up of a system for liquefying a feed gas stream comprising natural gas. The system has a feed gas compression and expansion loop, and a refrigerant system comprising a primary cooling loop and a sub-cooling loop. The feed gas compression and expansion loop is started up. The refrigerant system is pressurized. Circulation in the primary cooling loop is started and established. Circulation in the sub-cooling loop is started and established. A flow rate of the feed gas stream and circulation rates of the primary cooling loop and the sub-cooling loop are ramped up.

The invention relates to an installation for liquefying a cryogenic fluid, for example hydrogen, comprising a circuit for supplying fluid to be cooled that is provided with an upstream end and a downstream end connected in parallel to a plurality of cryogenic stores, a set of heat exchanger(s) in heat exchange with the supply circuit and a cooling device comprising a refrigerator with a cycle of refrigeration of a cycle gas, the installation comprising a set of liquid withdrawal ducts provided with a set of valve(s) and connecting the stores to at least one connecting end, the installation comprising a common heater connected in parallel to the plurality of cryogenic stores for fluid via a set of pressurization ducts provided with valves and configured to allow the pressurization of each of the cryogenic stores via the common heater.

In the LNG plant, heat is provided to natural a gas processing system, including a pre-treatment unit and/or a liquefaction unit and/or an evaporation unit, by exploiting heat recovered through a steam generator of the plant that is thermally coupled to an exhaust outlet of a gas turbine of the plant. A heat transfer fluid circuit system with a circulating heat transfer fluid includes a first portion and a second portion; the first portion is located in a section of the steam generator to extract heat from to exhaust gases; the section is located between a stack and an evaporation section; the second portion is thermally coupled to the gas processing system so to provide heat thereto for example through an heat exchanger.

A natural gas pretreatment system includes a heat exchanger having a first inlet, a second inlet, a first outlet, and a second outlet. The first inlet receives a first pressurized gas stream having a first input temperature, and the second inlet receives a second pressurized gas stream having a second temperature. The second temperature is higher than the first temperature. The first outlet outputs the first gas stream; upon exiting the heat exchanger, the first gas stream has a first output temperature higher than the first input temperature. The second outlet outputs the second gas stream; upon exiting the heat exchanger, the second gas stream has a second output temperature lower than the second input temperature. The system further includes a pipeline network operable to receive the first pressurized gas stream.