A process and plant are proposed for separating a feed mixture predominantly or exclusively containing carbon monoxide and hydrogen, in which the feed mixture is subjected to a cryogenic separation process in which a carbon monoxide-rich liquid and at least one residual gas mixture which is depleted in carbon monoxide and enriched in hydrogen, in comparison with the feed mixture, are formed. It is intended that the at least one residual gas mixture is subjected to a membrane separation process in which at least one hydrogen-rich permeate and at least one carbon monoxide-rich retentate are formed, wherein the or at least one of the carbon monoxide-rich retentates is recirculated to the cryogenic separation process.

An ammonia plant is disclosed, where ammonia purge gas (20), is sent to a cryogenic recovery unit, said recovery unit comprising means of cooling (102, 202, 302, 402, 502) and a high-pressure phase separator (103, 203, 303, 403, 503) operating at loop pressure; inside said unit the purge gas (20) is cooled to a cryogenic temperature, and a partial liquefaction of methane and argon is achieved; the high-pressure phase separator separates the cooled stream into a gaseous stream and a bottom liquid; the gaseous stream is reheated in a passage of a heat exchanger; the unit is then capable to export a gaseous stream (123, 223, 323, 423, 523) containing nitrogen and hydrogen at loop pressure, that can be reintroduced at the suction side of the circulator (4) of the loop.

A process and a plant for cooling a synthesis gas produced by catalytic steam reformation of a hydrocarbonaceous feed gas, which is cooled by heat exchange with boiler feed water for its conversion into steam, by separating the resulting aqueous condensate, wherein the further cooling is effected in that the gas passes through several series-connected cooling stages and comprises the heat exchange with the feed gas, with degassed and non-degassed boiler feed water for generating the steam required for the steam reformation, and with ambient air, and wherein condensate obtained after the last cooling stage is separated from the gas and the gas is discharged for the further treatment, wherein at least after a further cooling stage upstream of the last cooling stage a hot aqueous condensate is separated from the gas.

The present disclosure relates to systems and methods useful for providing one or more chemical compounds in a substantially pure form. In particular, the systems and methods can be configured for separation of carbon dioxide from a process stream, such as a process stream in a hydrogen production system. As such, the present disclosure can provide systems and method for production of hydrogen and/or carbon dioxide.

A hydrogen production system includes a desulfurization unit configured to remove a sulfur component from hydrocarbon gas. The system has a pre-reforming unit configured to convert hydrocarbons having two or more carbon atoms into methane (CH.sub.4) by reacting the hydrocarbon gas with water (H.sub.2O) vapor. The system has a mixed reforming unit configured to produce hydrogen (H.sub.2) and carbon monoxide (CO) by performing a mixed reforming reaction between the reaction product of the pre-reforming unit and carbon dioxide (CO.sub.2). The system has a separation unit for separating hydrogen (H.sub.2) and CO from the reaction product of the mixed reforming unit. The system has a first heat exchange unit configured to generate water vapor supplied to the pre-reforming unit using the heat of the reaction product of the mixed reforming unit.

A method and associated system for producing syngas containing hydrogen from waste plastics. The method and system provide for: pretreating waste plastics; producing pyrolysis gas by introducing the waste plastics pretreated in the pretreatment process into a pyrolysis reactor; producing in a lightening process pyrolysis oil by introducing the pyrolysis gas into a hot filter; and gasifying the pyrolysis oil, wherein a liquid condensed in the hot filter is re-introduced into the pyrolysis reactor. The system produces syngas containing hydrogen from the waste plastics.

A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

A method (100, 200) is proposed for obtaining hydrogen from a gaseous feed mixture rich in hydrogen, methane and hydrocarbons having two carbon atoms, wherein fluid of the feed mixture is cooled from a first temperature level to a second temperature level at a first pressure level such that one or more condensates are precipitated out of the fluid of the feed mixture, leaving a residual gas, fluid of the residual gas is further cooled to a third temperature level and subjected to a counterflow absorption at the first pressure level, thereby obtaining a top gas rich in hydrogen and methane and a sump liquid, fluid of the top gas is heated and subjected to pressure swing adsorption (9) at the first pressure level, to form a product stream which is rich in hydrogen and depleted in or free from methane, and fluid of the condensate or condensates and/or of the sump liquid is expanded from the first pressure level to a second pressure level and is fed into a low pressure demethanizer at the second pressure level. It is provided that the counterflow absorption is carried out using fluid which is taken from the low pressure demethanizer at the second pressure level, compressed in gaseous form to the first pressure level and cooled to the third temperature level. The invention also relates to a corresponding apparatus.

In a process for the production of carbon dioxide and hydrogen from a gas flow comprising at least hydrogen, at least one sulfur-comprising component and carbon dioxide originating from a Claus unit fed with a gas comprising at least 50 mol % of oxygen, the gas flow is compressed and dried in order to produce a compressed and dried gas flow and the compressed and dried gas flow is separated at a subambient temperature in order to produce at least a fluid enriched in carbon dioxide with respect to the compressed and dried gas flow and at least a fluid enriched in hydrogen with respect to the compressed and dried gas flow.

A hydrogen feed stream comprising one or more impurities selected from the group consisting of nitrogen, argon, methane, carbon monoxide, carbon dioxide, oxygen, and water, is purified using a cryogenic temperature swing adsorption (CTSA) process with high overall recovery of hydrogen. The waste gas from regenerating the CTSA may be used to improve the performance of upstream hydrogen processing steps.