oxygen against the flow direction of the helium stream other injector designs can be implemented as long as they disperse the oxygen sufficiently enough oxygen is added to react with the remainder of the hydrogen in the helium stream the gas stream passes through a gas distributor 49 to ensure that the gas is distributed equally to all the catalyst passages this distributor may consist of a perforated plate or some other dispersion device the helium stream then flows through a monolith catalyst 48 where the remainder of the hydrogen and oxygen react the catalyst consists of a platinum group metal deposited on a monolith substrate the monolith is in the form of a ceramic honeycomb a ceramic foam or a metal foil the hydrogen content of the helium is reduced to a few ppb the helium leaves spool piece 47 as stream 50 and it is processed further in the helium production plant cooling water or another cooling fluid enters heat exchanger 45 as stream 52 it is heated as it removes heat from the hot argon stream and it exits the heat exchanger as stream 53 helium stream 50 must be cooled before it can be processed further in the helium plant the system shown in fig5 envisions a.