A process for purifying a natural gas feed gas stream including methane and hydrocarbons, including step a): cooling the feed gas stream; step b): introducing the cooled stream into a first phase separator vessel in order to produce a liquid stream and a gas stream; step c): separating the gas stream resulting from step b) in a membrane unit from which a methane-enriched permeate stream and one partially condensed residue stream enriched in hydrocarbons exit; step d): introducing the residue stream resulting from step c) into a second phase separator vessel to produce a liquid stream and a gas stream; step e): introducing at least one portion of the liquid stream resulting from step d) into a JT expansion means; step f): heating at least one portion of the expanded by introduction into the heat exchanger used in step a) counter-current to the feed stream.

The present invention relates to a cold box cycle which allows for independent control of the heat supplied for reboilers associated with the separation columns. More specifically, the invention relates to the tight control of the hydrogen removal separation, thus avoiding the possibility of excess reboiling in this separation. Optimal reboiling also results in a lower temperature of the hydrogen depleted liquid from this separation. As this stream is used to provide a portion of the cooling at the cold end of the primary heat exchanger, lower temperatures facilitate cooling of the incoming syngas feed, reducing carbon monoxide (CO) losses into the crude hydrogen stream from the high pressure separator. Lower CO in the crude hydrogen allows for smaller hydrogen purification equipment.

Proposed is a process for producing ethylene wherein using a dehydrogenation of ethane a process gas containing at least ethane, ethylene and compounds having a lower boiling point than ethane and ethylene is formed, wherein using at least a part of the process gas a separation input is formed and subjected to a low-temperature separation (6) in which the separation input is cooled and in which one or more condensates are separated from the separation input, wherein the condensate(s) are at least partly subjected to a low-temperature rectification to obtain a gaseous first fraction and a liquid second fraction, wherein the gaseous first fraction contains at least the ethane and the ethylene in a lower proportion than in the separation input and the compounds having a lower boiling point than ethane and ethylene in a higher proportion than in the separation input. It is provided that the first fraction is at least partly subjected to a pressure swing adsorption (7) by means of which a third fraction containing predominantly or exclusively ethylene and ethane and a fourth fraction containing predominantly or exclusively methane and carbon monoxide are formed. A corresponding plant (100) likewise forms part of the subject matter of the present invention.

A method for recovering a helium product or intermediate product, wherein a first natural gas stream containing helium is supplied to a first natural gas processing unit and at least one second natural gas stream containing helium is supplied to at least one second natural gas processing unit, at least the first natural gas processing unit comprising helium recovery means via which the helium product is formed from at least a part of the first natural gas stream. At least temporarily a helium transfer from the at least one second natural gas stream to the first natural gas stream by means of a helium transfer arrangement comprising a membrane unit is performed before the first natural gas stream is provided to the first natural gas processing unit and before the at least one second natural gas stream is provided to the at least one second natural gas processing unit.

A method of stripping carbon dioxide from a stream of natural gas to be used in the production of liquid natural gas (LNG) comprises the steps of: passing a stream of natural gas through a stripping column; injecting a stripping agent into the stripping column, the stripping agent stripping carbon dioxide from the stream of natural gas and exiting the stripping column as a liquid phase; passing the stripping agent exiting the stripping column through a regenerator column to generate a carbon dioxide gas stream and a recovered stripping agent stream; and cooling the recovered stripping agent stream using a cryogenic vapour generated in the production of LNG and injecting the cooled, recovered stripping agent stream into the stripping column as the stripping agent.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.

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.

The present invention is directed to a method and system of separating carbon monoxide from syngas mixtures with high methane content by cryogenic means where a partial condensation cycle is generally employed, and more specifically towards combining the methane-rich liquid exiting the distillation column with a lower-boiling mixture so that the boiling point of the combined stream is lower than the boiling point of the methane-rich liquid.

A system for recovering valuables from vent gas in polyolefin production is disclosed. The system includes a compression device, a drying device, a condensation and separation device, and a membrane separation device that are connected to each other in sequence. The drying device includes a first adsorption bed and a second adsorption bed which are in parallel connection with each other and in which a desiccant is provided, and a third adsorption bed which is in communication with the first adsorption bed and the second adsorption bed respectively and in which a desiccant is provided. The first adsorption bed and the second adsorption bed are in an adsorption process and a regeneration process alternately, and the third adsorption bed is in an auxiliary regeneration process. A process for recovering valuables from vent gas in polyolefin production is further disclosed. When the system and the process are used, one part of the normal temperature compressed gas stream output by the compression device directly serves as a regeneration gas for regeneration of saturated desiccant in adsorption bed, and it is unnecessary for external supply of regeneration gas, whereby the actual recovery of nitrogen can be effectively improved. Membrane separation technology is combined, and hydrocarbon recovery can be effectively improved as well.

The present invention is directed to a method of separating carbon monoxide from syngas mixtures by cryogenic means where a partial condensation cycle is generally employed, and more specifically varying refrigeration generation based on income feed composition of the hydrocarbon feedstock being processed.