of steam produced is definitely reduced with respect to a prior art steam reforming process but a large quantity of electricity is produced in the alternator 30 which is not necessarily desired at the same time as the production of hydrogen the description of the flow chart for the process of the present invention is made with the help of fig2 the elements of the flow chart of the present invention and the flow chart of the hygensys process which have the same function have the same numerals in fig1 and 2 this clearly shows that the flow chart of the invention is simplified compared with the hygensys flow chart since the elements 29 30 and 45 have disappeared and the complex exchangers 7 and 6 have been replaced by the simple exchangers 7 1 and 6 1 the term u201c simple exchangers u201d means shell and tube exchangers such as those corresponding to the tema or codap manufacturing standard this point is of importance as regards economics since special exchangers can easily be twice or even three times the price of simple exchangers more precisely the flow chart for the invention can be described as follows the feed preferably natural gas is sent to the exchanger reactor 25 via the line 1 as a mixture with steam arriving via the line 17 the catalyst is disposed in bayonet tubes 24 heated by pressurized flue gases 34 originating from a compressor 32 associated with a turbine 33 and re heated in a combustion chamber 27 by combustion of a fuel gas principally constituted by purge.