Partial oxidation, autothermal and dry reforming

The moderately exothermic catalytic partial oxidation process for methane. 

The use of air is convenient for automotive applications, but if the autothermal scheme were to be used for large industrial plants, dedicated oxygen production for the feed would be preferable, e.g. due to concerns over the volume of N2 to be handled and the associated size of heat exchangers (Rostrup-Nielsen, 2000). 

Hydrogen production by partial oxidation from methane increases with process temperature, but reaches a plateau value at around 1000 K (Fukada et ah, 2004). The theoretical efficiency is similar to that of conventional steam reforming, but less water is required (Lutz et ah, 2004). 

Gasoline and other higher hydrocarbons may be converted to hydrogen on board cars by the autothermal processes, using suitable catalysts (Ghen-ciu, 2002 Ayabe et ah, 2003 Semelsberger et ah, 2004). Partial oxidation may also be combined with the palladium-catalyst membrane reactors mentioned in section 2.1.1 (Basile et ah, 2001). 

As an alternative to conventional steam reforming, methane could be reformed in a stream of carbon dioxide rather than steam of water. 

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