Reforming catalytic partial oxidation

A part from the steam reforming there are other interesting applications in the petrochemical industry methane dry reforming, catalytic partial oxidation, auto-thermal reforming, water gas shift, H2S cracking, and hydrocarbon dehydrogenation. More details about some of these applications are given in Chaps. 5, 6, 7, 8, and 9. 

The main part of the fuel processing system is the reformer that produces the hydrogen needed for the fuel cells, no matter what power is needed. Generally, there are three routes for the fuel conversion in microreactors steam reforming, catalytic partial oxidation and oxidative steam reforming. 

The product gas from steam reforming, catalytic partial oxidation, partial oxidation, or gasification processes contains in all cases significant amounts of carbon monoxide and carbon dioxide. Since the feed gas for the ammonia synthesis loop must be completely free of these compounds, they must be removed in the gas preparation part of the plant. Carbon monoxide is removed in a conversion step by the so-called water-gas shift reaction or just the shift reaction, in some cases followed by further conversion by selective oxidation. 

The catalytic partial oxidation of methane for the production of synthesis gas is an interesting alternative to steam reforming which is currently practiced in industry [1]. Significant research efforts have been exerted worldwide in recent years to develop a viable process based on the partial oxidation route [2-9]. This process would offer many advantages over steam reforming, namely (a) the formation of a suitable H2/CO ratio for use in the Fischer-Tropsch synthesis network, (b) the requirement of less energy input due to its exothermic nature, (c) high activity and selectivity for synthesis gas formation. 

Ahmed, S. et al., Catalytic partial oxidation reforming of hydrocarbon fuels, Proc. of 1998 Fuel Cell Seminar, Palm Springs, CA, 242,1998. 

The other two main processes for conversion of methane into synthesis gas are partial oxidation and CO2 reforming. In the 1940s, Prettre et al. (3) first reported the formation of synthesis gas by the catalytic partial oxidation of CH4... 

They used a Ni-containing catalyst. In contrast to steam reforming of methane, methane partial oxidation is exothermic. However, the partial oxidation requires pure oxygen, which is produced in expensive air separation units that are responsible for up to 40% of the cost of a synthesis gas plant (2) (in contrast, the steam reforming process does not require pure oxygen). Therefore, the catalytic partial oxidation of methane did not attract much interest for nearly half a century, and steam reforming of methane remained the main commercial process for synthesis gas manufacture. 

In addition to SMR, other technologies are used for syngas production from natural gas that involve addition of oxygen or air. The catalytic partial oxidation (CPO) reaction is given in Reaction (3) and in autothermal reforming (ATR) this reaction is combined with Reactions (1) and (2). 

Private communication with Johnson Matthey Technology Centre, Reading, England, February 2000. 17. "Catalytic Partial Oxidation Reforming of Hydrocarbon Fuels," S. Ahmed, et al., ANL, Pg. 242, Fuel Cell Seminar Abstracts, Courtesy Associates, Inc., November 1998. 

Hydrogen production by catalytic steam reforming and partial oxidation of hydrocarbons has been the most efficient, economically and widely used process for the... 

Figure 3 Thermal integration of reformer with fuel cell system (a) Catalytic partial oxidation reformer, (b) Catalytic steam reformer, and (c) Autothermal reformer...

Air Blow Secondary Reformer 2 Catalytic Partial Oxidation... 

In petroleum refineries, off-gas streams from catalytic reforming processes represent the largest source of recoverable hydrogen, exceeding by a wide margin the amount of make up hydrogen produced by steam reforming and partial oxidation. 

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