The present disclosure relates to a hydrogen liquefaction system, comprising a hydrogen pipe, where gaseous hydrogen is introduced at a front end, heat exchange occurs in a heat exchange unit leading to liquefaction of gaseous hydrogen into liquid hydrogen; a pre-cooling device formed between the front end of the hydrogen pipe and the first heat exchange unit; an oxygen pipe, where gaseous oxygen is introduced at a front end, heat exchange occurs in the pre-cooling device leading to liquefaction of gaseous oxygen into liquid oxygen; and a heat exchange device, which is in thermal contact with the first heat exchange unit of the hydrogen pipe so as to perform heat exchange with the first heat exchange unit of the hydrogen pipe such that pre-cooled gaseous hydrogen can be liquefied into liquid hydrogen.

Process for the synthesis of ammonia from a make-up gas containing hydrogen and nitrogen, said process comprising: generation of a synthesis gas (8) containing hydrogen and nitrogen in a molar ratio lower than 3, inside a front-end section (2); a first cryogenic purification, designed to remove nitrogen and raise said molar ratio; conversion of the synthesis gas into ammonia (13) inside a high-pressure synthesis loop (6), with extraction from said loop of a purge stream (14) containing hydrogen and inert gases; wherein at least a portion of said purge stream (14) undergoes a further purification in order to recover at least part of the hydrogen contained therein, obtaining at least one stream (15, 15a, 16, 18) containing recovered hydrogen which is recycled to the process.

Disclosed herein is a boil-off gas reliquefaction apparatus. The boil-off gas reliquefaction apparatus includes: a plurality of compressors arranged in parallel to compress boil-off gas discharged from a storage tank; a reliquefaction unit reliquefying the boil-off gas compressed by each of the plurality of compressors; and a plurality of supply lines providing a path through which the boil-off gas is supplied from the plurality of compressors to the reliquefaction unit and a path through which the boil-off gas flows in the reliquefaction unit, wherein the plurality of supply lines is arranged independently of one another without being joined together.

A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units in which vaporized gases are condensed and then returned into at least one cargo tank for the respective LPG cargo type. The method is further comprising: using the reliquefaction units, at a minimum one running, as to condense vapor from the first cargo type; passing the condensed vapor through a heat exchanger; simultaneously flowing vapor from the second cargo type through the heat exchanger as to condense vapor by means of heat exchanging with the condensed vapor; and returning the condensed vapors leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.

A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units (300, 400) in which vaporized gases are condensed and then returned into at least one cargo tank (100) for the respective LPG cargo type. The method is further comprising: using the reliquefaction units (300, 400), at a minimum one running, as to condense vapor from the first cargo type; passing the condensed vapor through a heat exchanger (500); simultaneously flowing vapor from the second cargo type through the heat exchanger (500) as to condense vapor by means of heat exchanging with the condensed vapor; and returning the condensed vapors leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.

It is proposed to integrate a gas processing unit with a liquefaction unit. The industrial gas stream may be but is not limited to air gases of oxygen, nitrogen argon, hydrocarbon, LNG, syngas or its components, CO.sub.2, or any other molecule or combination of molecules. It is proposed to integrate the underutilized process inefficiencies of a gas processing unit into the liquefaction unit to produce a liquid at a reduced operating cost. The gas processing unit may be any system or apparatus which alters the composition of a feed gas. Examples could be, but are not limited to, a methanol plant, steam methane reformer, cogeneration plant, and partial oxidation unit.

The invention relates to a method and an installation for producing liquid helium, said installation comprising a cooling/liquefaction device comprising a working circuit that subjects a helium-enriched working fluid to a thermodynamic cycle in order to produce liquid helium, said circuit comprising at least one working fluid compression body and a plurality of heat exchangers. The installation also comprises a plurality of fluid recovery lines having respective upstream ends to be selectively connected to respective reservoirs, and a first collection line having an upstream end connected to the recovery lines and a downstream end connected to a receiving body that can supply the working circuit with a working fluid. The installation is characterized in that it comprises at least one second and one third collection line that each have an upstream end connected to the recovery lines and a downstream end connected to the working circuit, the upstream ends of the second and third collection lines being connected at separate determined positions of the working circuit, that respectively correspond to separate temperature levels of the working fluid in the working circuit.

The method is carried out for continuously producing a liquefied methane gas (LMG) from a pressurized mixed methane gas feed stream. It is particularly well adapted for use in relatively small LMG distributed production plant, for instance those ranging from 400 to 15,000 MT per year, and/or when the mixed methane gas feed stream has a wide range of nitrogen-content proportions, including nitrogen being substantially absent. The proposed concept can also be very useful in the design of medium-scale and/or large-size plants, including ones where the nitrogen content always remains above a certain threshold. The methods and arrangements proposed herein can mitigate losses of methane gas when venting nitrogen, for instance in the atmosphere.

The system is provided for generating a mixed methane gas feed stream using at least one source of biogas and an alternate source of methane gas. The system includes a biogas subsystem, a control device for the methane gas from the at least one alternate source of methane gas, and a vertically-extending gas mixing vessel. A method of controlling a methane gas mass flow rate of a mixed methane gas feed stream is also disclosed. The proposed concept is particularly well adapted for situations where an uninterrupted and relatively constant input of methane gas is required to ensure an optimum operation of, for instance, a LMG production plant.

A method for the production of liquefied natural gas is provided. The method may include providing a high pressure natural gas stream, splitting the high pressure natural gas stream into a first portion and a second portion, and liquefying the first portion of the high pressure natural gas stream to produce an LNG stream. The refrigeration needed for cooling and liquefaction of the natural gas can be provided by a closed nitrogen refrigeration cycle and letdown of the second portion of the high pressure natural gas stream.