Oxidation autothermal reforming

Reversed-flow gas chromatography (RF-GC) has been successfully used to characterize solid catalysts under conditions compatible with the operation of real catalysts. RF-GC is not limited to chromatographic separation since RF-GC is accompanied by suitable mathematical analysis of the chromatographic data, the simultaneous determination of various physicochemical parameters is possible. Thus, various catalytic processes related to the operation of fuel cell units such as steam reforming, catal3dic partial oxidation, autothermal reforming, as well as water-gas shift (WGS) reaction and selective CO oxidation can be studied. 

Platinum is prone to CO adsorption at temperatures of around 100 C and below. For this reason, care has to be taken with respect to the purity of hydrogen, in particular for hydrogen liberated from a C-containing fuel by a reforming process (steam reforming, partial oxidation, autothermal reforming). 

For a systematic structure, it is practical to distinguish between the actual synthesis gas generation and the synthesis gas processing. In processes requiring more or less pure oxygen (partial oxidation, autothermal reforming), the air separation plant that may have to be installed has to be considered with regard to the selection of the process and the economic evaluation [5.23]. 

ATR(l) [Autothermal reforming] A process for making CO-enriched syngas. It combines partial oxidation with adiabatic steam-reforming. Developed in the late 1950s for ammonia and methanol synthesis. Further developed in the 1990s by Haldor Topsoe. 

CAR [Combined autothermal reforming] A "reforming process for making "syngas from light hydrocarbons, in which the heat is provided by partial oxidation in a section of the reactor. Developed by Uhde and commercialized at an oil refinery at Strazske, Slovakia, in 1991. 

Oxidative Steam Reforming (OSR) / Autothermal Reforming of Ethanol... 

Oxidative steam reforming/autothermal reforming of ethanol... 

Fig. 11 Free energy changes in the oxidative steam reforming/autothermal reforming of ethanol, acetaldehyde and methane.

Table 7 References on oxidative steam reforming (OSR) and autothermal reforming of ethanol for hydrogen production... 

Scheme 6 Proposed reaction pathway for the oxidative steam reforming/ autothermal reforming of ethanol. The dehydration into ethylene intermediate followed by ethylene reforming are not shown. 

This review analyzed the chemistry involved, thermodynamics, catalysts used, reaction pathways and mechanisms of various reforming techniques reported for the conversion of ethanol into H2-rich gas. The known reforming processes are broadly classified into three categories, namely steam reforming of ethanol (SRE), partial oxidation of ethanol (POE) and oxidative steam reforming (OSR)/autothermal reforming of ethanol. All these reactions are thermodynamically favorable even at lower temperatures, above 200 °C. 

Fuel-reforming process should be understood in a broader sense as including all options such as partial oxidation (POX), steam reforming (SR), and their combination, i.e., autothermal reforming (ATR). In general, the fuel-reforming process can be represented by the following equation ... 

Table 7.2 The Stoichiometry for Autothermal Reforming (ATR), Partial Oxidation (POX), and Steam Reforming (SR)...

S adsorption Partial oxidation Low temperature Oz bleeding Autothermal reforming Methanation... 

As well as the previously described methods of hydrogen production, there are other commercial processes whose application is restricted to specialised production conditions. These include the partial oxidation of heavy hydrocarbons, autothermal reforming and the Kvcerner process. In addition, there are numerous production processes that are still at the basic research stage, but show promising potential. These primarily include thermochemical hydrogen production, photochemical and biological processes. The main characteristics of these methods are outlined below. For a more detailed discussion, please refer to the relevant specialist literature. 

Today, different processes (steam reforming, autothermal reforming, partial oxidation, gasification) are available and commercially mature for hydrogen production from natural gas or coal. These processes would have to be combined with technologies for C02 capture and storage (CCS), to keep the emissions profile low. A power plant that combines electricity and hydrogen production can be more efficient than retrofitted C02 separation systems for conventional power plants. 

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). 

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