Air, steam, and natural gas are mixed in a conical combustion zone at the top of the refractory lined reactor. In this zone both partial oxidation and steam reforming reactions take place. In the catalyst zone the reactions, including the steam-methane reaction, are brought to near equilibrium. The reactor operates at a pressure dictated by the discharge pressure of the gas turbine's air compressor. The key process results are presented in table 1.
Key process results.
All the cases considered rely on the availability of a gas turbine which can burn hydrogen-rich mixtures. It seems clear that the higher the hydrogen concentration the more doubts there are about the availability of suitable turbines. The concerns about modification of high efficiency gas turbines to burn hydrogen-rich mixtures appear to be about the low energy density and high flame speed of hydrogen and means of ensuring low NOx emissions. Attempts are being made to clarify the situation. The extent to which air-blown partial oxidation is an established technology for use with natural gas as a feed is uncertain.