A process for producing one or more olefins is proposed in which a reaction input containing one or more paraffins is formed and in which a portion of the paraffin(s) present in the reaction input is converted by oxidative dehydrogenation into the olefin(s) to obtain a process gas, wherein the process gas contains at least the olefin(s), the unconverted paraffin(s), oxygen and carbon monoxide and wherein at least a portion of the process gas is subjected to a low temperature separation in which at an operating pressure level one or more gas fractions enriched in oxygen and carbon monoxide compared to the process gas are formed. It is provided that in the low temperature separation in the formation and/or for the conduction of the or at least one of the gas fractions one or more containers and/or one or more conduits having a burst pressure of at least ten times the operating pressure level are used and that the container or at least one of the containers via the or at least one of the conduits is connected to one or more heat exchangers, wherein a total length of the or of the at least one conduit between the or the at least one container and the heat exchanger(s) is not more than fifty times the internal diameter of said conduit. A corresponding plant (100) likewise forms part of the subject matter of the invention.

Methods and apparatus for the production of ultra high purity carbon monoxide having a carbon dioxide content of 0.1 ppm or less is disclosed. Carbon dioxide is removed from a product stream using a reversing heat exchanger to freeze the carbon dioxide out of the product stream, This provides the ultra high purity carbon monoxide product which meets the requirements of the electronic industry applications.

A process for producing one or more olefins is proposed in which a reaction input containing one or more paraffins is formed and in which a portion of the paraffin(s) present in the reaction input is converted by oxidative dehydrogenation into the olefin(s) to obtain a process gas, wherein the process gas contains at least the olefin(s), the unconverted paraffin(s), oxygen and carbon monoxide and wherein at least a portion of the process gas is subjected to a low temperature separation in which at an operating pressure level one or more gas fractions enriched in oxygen and carbon monoxide compared to the process gas are formed. It is provided that in the low temperature separation in the formation and/or for the conduction of the or at least one of the gas fractions one or more containers and/or one or more conduits having a burst pressure of at least ten times the operating pressure level are used and that the container or at least one of the containers via the or at least one of the conduits is connected to one or more heat exchangers, wherein a total length of the or of the at least one conduit between the or the at least one container and the heat exchanger(s) is not more than fifty times the internal diameter of said conduit. A corresponding plant (100) likewise forms part of the subject matter of the invention.

A method for recovering a helium product fraction (6) from a nitrogen- and helium-containing feed fraction (3) is described, wherein the nitrogen- and helium-containing feed fraction (3) is partially condensed (E1), separated into a first helium-enriched fraction (5) and a first nitrogen-enriched fraction (8) and the former is cleaned again in an adsorptive manner.

According to the invention, the separation is carried out in a separation column (T), which is supplied with the first nitrogen-enriched fraction (8) as return flow and with a sub-flow of the second nitrogen-enriched fraction as stripping gas (12), wherein the stripping gas quantity (12) is set such that a third nitrogen-enriched fraction (20), which contains at least 30% of the nitrogen contained in the first nitrogen-enriched fraction (8), can be recovered in the separation column (T).