초록 ▼

A process is disclosed for the cryogenic purification of industrial by-product gas streams containing recoverable hydrogen. Two feed streams, one of which contains non-readily condensible compounds having boiling points below that of methane, are passed through a successive series of cooling and sep

A process is disclosed for the cryogenic purification of industrial by-product gas streams containing recoverable hydrogen. Two feed streams, one of which contains non-readily condensible compounds having boiling points below that of methane, are passed through a successive series of cooling and separation stages. A condensed bottom fraction is separated in a separation drum from an overhead of increasing purity at each stage, and the condensates are combined into one or more condensate streams. The overhead from the stream containing the non-readily condensible compounds is injected into a combined condensate stream, reducing the temperature thereof, and the combined condensate stream is passed back through the heat exchange means to provide refrigeration for the system. An increased amount of hydrogen product is thereby recovered. Additionally, the condensate streams may be passed separately back through the heat exchange means to recover their more valuable components which are suitable for further purification. In particular, unsaturated hydrocarbons can be recovered in a more concentrated form for improved ethylene and propylene recovery.

대표청구항 ▼

A process for the cryogenic purification of industrial by-product gas streams containing impure hydrogen in recoverable amounts, one of the by-product hydrogen gas streams also containing non-readily condensible impurities having boiling points below that of methane, which comprises the steps of: (a

A process for the cryogenic purification of industrial by-product gas streams containing impure hydrogen in recoverable amounts, one of the by-product hydrogen gas streams also containing non-readily condensible impurities having boiling points below that of methane, which comprises the steps of: (a) passing a first and second hydrogen containing gas streams through a successive series of cooling and separation stages, the first gas stream containing hydrocarbons as substantially the sole impurities and the second gas stream containing nitrogen or other non-readily condensible impurities having boiling points below that of methane; (b) separating at each such separation stage from the first and second hydrogen containing gas streams a purified gas stream overhead from a condensed bottom fraction, the purified overhead of the second gas stream also containing the non-readily condensible impurities, and combining the bottom fractions into one or more condensate streams; (c) injecting the overhead containing the non-readily condensible impurities from the final separation stage into a condenstate stream containing combined bottom fractions; and (d) recovering the overhead of the first stream as hydrogen product of desired purity.