In order to produce syn-gas without either consuming or producing much heat, modern plants are usually combining exothermic partial oxidation with endother-mic steam reforming in order to have an overall thermodynamically neutral reaction while obtaining a syn-gas with a composition suited for methanol synthesis (S close to 2). In this process, termed "autothermal reforming", the heat produced by the exothermic partial oxidation is consumed by the endothermic steam reforming reaction. Partial oxidation and steam reforming can be conducted simultaneously in the same reactor by reacting methane with a mixture of steam and oxygen. Having only one reactor lower the costs and complexity of the system. However, because the two reactions are optimized for different temperature and pressure conditions, they are generally conducted in two separate steps. After the steam reforming step, the effluent from the reformer's outlet is fed to the partial oxidation reactor where all the residual methane is consumed . The oxygen required for the oxidation step means that an air separation plant is needed, but to avoid the construction of such a unit the use of air rather than oxygen is also possible. The produced syn-gas will however contain a large amount of nitrogen and require special processing before conversion to methanol. Thus, most modern methanol plants use pure oxygen.
Was this article helpful?
Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.