A process for liquefying and subcooling a hydrocarbon-rich fraction, particularly natural gas, is described wherein, once cooled down, the fraction is subjected to a partial condensation to remove heavy hydrocarbons, particularly benzene, by the steps of: a) the liquefied hydrocarbon-rich fraction is subcooled in a separate heat exchanger (normal mode), b) the supply of the liquefied hydrocarbon-rich fraction to the heat exchanger is interrupted at the latest when a defined solid deposition value in the heat exchanger is reached (cleaning mode), c) the solid in the heat exchanger is melted with a defrost gas and drawn off from the heat exchanger and d) the liquefied hydrocarbon-rich fraction is subsequently returned to the heat exchanger.

A leakage detection system includes: a gas supply line along which boil-off gas is supplied to a compressor; a reliquefaction line along which the compressed boil-off gas is cooled and reliquefied through a heat exchanger and is returned to a storage tank; a refrigerant circulation line along which a refrigerant is circulated; a refrigerant compressor to compress the refrigerant discharged from the heat exchanger; a refrigerant expander expanding and cooling the compressed refrigerant compressed by the refrigerant compressor and having been cooled through the heat exchanger and supplying the cooled refrigerant back to the heat exchanger; and a refrigerant charge line connecting an inventory tank filled with nitrogen to an upstream side of the refrigerant compressor. Upon initial start-up or restart of a reliquefaction process, the nitrogen is supplied to the upstream side of the refrigerant compressor via the refrigerant charge line to detect leaks in the refrigerant circulation line.

A system for processing gas streams has the form of, and is disposed in, an intermodal container. The container has a processing compartment with one or more cryogenic cells disposed in it, and is maintained in at least a partially evacuated condition, below atmospheric pressure. A second compartment has support equipment that is connected to the one or more cryogenic cells in the first compartment. Methods for managing such a system include maintaining the first compartment in the partially evacuated condition. In response to an increase in pressure within the first compartment, a controller may analyze the nature of the pressure increase. In case of fire or fire hazard, the controller may discharge inert gas from cores of the one or more cryogenic cells.