Nowadays hydrogen is mainly produced by the steam reforming process and sulfur is mainly produced by (variants of) the Claus process. If environmental pollution by emission of carbon dioxide, sulfur compounds, nitrogen oxides and heat is taken into consideration, this environmental aspect may reverse the situation one day.
A potential source of both hydrogen and sulfur is hydrogensulfide. If hydrogensulfide is cracked, the main product are hydrogen and sulfur.
The recovery of hydrogen and sulfur from waste hydrogensulfide may be an interesting alternative to the separate manufacture of hydrogen in a steam reforming plant and sulfur in a Claus plant.

The exergy concept is a method which can make a good comparison between the processes described above. This report presents the results of an exergy analysis for a steam reforming plant and for a hydrogensulfide cracking plant.

The exergy analysis show an exergy efficiency of 74.9 % for the hydrogensulfide cracking process and 66.2 % for the steam reforming process. It is also shown that for both processes the exergy is mainly lost in the furnace (71 to 88% of the total exergy loss).

It is recommended to make an exergy analysis of a Claus plant as well. It would then be possible to compare the total exergy use of a Claus plant and a steam reforming plant together to the exergy use of a hydrogensulfide cracking plant alone.