Patent GB-991843-A (GB)
Title: Process for the preparation of substantially pure hydrogen gas
IPC: C10K1/12
Filed: 1963-09-02
Abstract: A process for the preparation of substantially pure hydrogen gas by catalytic cracking of hydrocarbons with steam and subsequent conversion of the carbon monoxide contained in the resultant gas, the conversion being <PICT:0991843/C1/1> carried out in one or more stages and carbon dioxide being washed out of the gas after the or each conversion stage by a washing solution regenerated by boiling and then re-used, is characterized in that the gas stream leaving the or each conversion stage is fed (separately) to a boiler for heating, by indirect heat transfer, the enriched washing solution in the regeneration thereof, the gas stream(s) being thereby cooled by enriched washing solution so that the steam contained in such gas stream(s) is partially condensed.  As shown in the Figure, a hydrogen/carbon monoxide mixture leaving a cracking oven 1 passes successively through a first CO2 converter 2, an indirect heat exchanger 18, a first CO2 washer 3, a second CO2 converter 4, again through heat exchanger 18 and finally through the second CO2 washer 5 before being withdrawn as product from line 26.  The CO2 washing liquid passes in a cycle from regenerator 6, which is in the form of a separating column, through lines 27 and 30 to the second washer 5, and back through line 32 to the top of regenerator 6.  The solution at the foot of regenerator 6 is boiled in boiler 18 which is an indirect heat exchanger, having a pair of heating coils connected to heat exchangers 17, 24, the solution circulating from the regenerator 6, through pipe 33, the boiler and pipe 36.  The mixture of CO2 and steam which escapes through pipe 37 is passed to cooler 37 and carbon dioxide is withdrawn at 39 and condensate flows back to the washing solution circuit through pipe 40.ALSO:<PICT:0991843/C4-C5/1> A process for the preparation of substantially pure hydrogen gas by catalytic cracking of hydrocarbons with steam and subsequent conversion of the carbon monoxide contained in the resultant gas, the conversion being carried out in one or more stages and carbon dioxide being washed out of the gas after the or each conversion stage by a washing solution regenerated by boiling and then reused is characterized in that the gas stream leaving the or each conversion stage is fed (separately) to a boiler for heating, by indirect transfer, the enriched washing solution in the regeneration thereof, the gas stream(s) being thereby cooled by enriched washing solution so that the steam contained in such gas stream(s) is partially condensed.  As shown in the Figure, a hydrogen/carbon monoxide mixture leaving a cracking oven 1 passes successively through a first CO2 converter 2, an indirect heat exchanger 18, a first CO2 washer 3, a second CO2 converter 4, again through heat exchanger 18 and finally through the second CO2 washer 5 before being withdrawn as product from line 26.  The CO2 washing liquid passes in a cycle from regenerator 6 (which is in the form of a separating column), through lines 27 and 30 to the second washer 5, and back through line 32 to the top of regenerator 6.  The solution at the foot of regenerator 6 is boiled in boiler 18, which is an indirect heat exchanger having a pair of heating coils connected to heat exchangers 17, 24, the solution circulating from the regenerator 6, the boiler and pipe 36. The mixture of CO2 and steam which passes through pipe 37 is passed to cooler 37 and carbon dioxide is withdrawn at 39 and condensate flows back to the washing solution circuit through pipe 40.