1. Presentation and background

In the manufacture of syngas, C and/or C _n H _m are converted into CO, CO ₂ , H ₂ with the occasional addition of N ₂ , oxygen being supplied either directly, or by steam or air. In terms of syngas utilization, a distinction is essentially made between:

• Purified H ₂ which is the essential component of all hydrogenation reactions ;

• the CO + CO ₂ + H ₂ mixture which is at the origin of methanol synthesis;

• CO alone,...