Steam Methane Reforming
A majority of the methanol plants operating today are based on steam reforming of natural gas. This technology is attractive at capacities greater than 2500-3000 mtpd methanol and the main licensor is Haldor Topsøse.
These equations show that there is an excess of hydrogen, i.e. more hydrogen is obtained than is required to convert the carbon oxides to methanol. One of the options is the addition of CO2 to match the excess hydrogen. This obviously reduces the feed and fuel requirement per ton of methanol. CO2 can be admitted to the reformer with feed and steam, thereby increasing the CO to CO2 ratio in the syngas, which in turn increases the carbon efficiency in the synthesis process. Alternatively it can be admitted directly into the methanol loop. The total energy consumption for this process scheme per metric ton of grade AA methanol is about 32.4 GJ without CO2 addition and about 29.5 GJ with CO2 addition.
