Methane oxidation steam reforming

Feasibility Study for Combined Methane Oxidation/Steam Reforming in an Integrated Heat Exchanger... 

Seo et al. investigated thoroughly the interplay of the 0/C ratio and S/C ratio on carbon formation and hydrogen yield for methane oxidative steam reforming by thermodynamic calculations [66]. A minimum S/C ratio of 1.4 had been identified previously as being necessary to prevent carbon formation in the absence of oxygen [66] (see Section 3.1). When air was fed to the system on top of steam and methane, this minimum value decreased, as shown in Figure 3.19. 

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

Interesting aspects of autothermal reactor operation arise if an endothermic synthesis reaction is coupled with an exothermic reaction in such a way that the combination is weakly exothermic An example has been given by Amoco for the oxidative steam reforming of methane [48] The application to styrene synthesis has so far been limited to simulation studies (see [49] and references therein)... 

Nurunnabi, M., Fujimoto, K.-I., Suzuki, K., Li, B., Kado, S., Kunimori, K., and Tomishige, K. Promoting effect of noble metals addition on activity and resistance to carbon deposition in oxidative steam reforming of methane over NiO-MgO solid solution. Catalysis Communications, 2006, 7 (2), 73. 

Performance and Characterization of NiO-MgO Solid Solution Modified with Noble Metals in Oxidative Steam Reforming of Methane... 

The additive effect of noble metals to NiO-MgO solid solution on the activity and on the resistance to the carbon deposition in oxidative steam reforming of methane under pressurized condition (I.O MPa) was investigated. It was found that the addition of small amount of Rh or Pd was effective to enhance the activity and to suppress the carbon deposition. The Pd and Rh K-edge EXAFS analysis indicated that M-Ni alloy phase (M=Rh or Pd) was formed, and FTIR spectra of CO adsorption suggests that the alloy could be formed on the surfece of bimetallic particles. 

Over Pd/MgO catalysts, large amount of carbon was deposited during oxidative steam reforming of methane at 1.0 MPa, and the amount increased with increasing loading amount of Pd on MgO. And almost the same amount of deposited carbon was obtained over 0.5% Pd/Nio.2Mgo.80. As shown in Figure... 

Parizotto NV, Zanchet D, Rocha KO, Marques CMP, Bueno JMC (2009) The effect of Pt promotion on the oxi-reduction properties of alumina supported nickel catalysts for oxidative steam-reforming of methane temperature-resolved XAFS analysis. Appl Catal A 366 122-129... 

Nurunnabi et al. observed improved performance of their Nio.2Mgo.8O catalyst for oxidative steam reforming of methane when doping it with 0.1 wt.% palladium [219]. 

A second reaction for the oxidation of methane is steam reforming. 

Na.tura.1 Ga.s Reforma.tion. In the United States, most hydrogen is presently produced by natural gas reformation or methane—steam reforming. In this process, methane mixed with steam is typically passed over a nickel oxide catalyst at an elevated temperature. The reforming reaction is... 

Synthesis gas, a mixture of CO and o known as syngas, is produced for the oxo process by partial oxidation (eq. 2) or steam reforming (eq. 3) of a carbonaceous feedstock, typically methane or naphtha. The ratio of CO to may be adjusted by cofeeding carbon dioxide (qv), CO2, as illustrated in equation 4, the water gas shift reaction. 

Steam Reforming Processes. In the steam reforming process, light hydrocarbon feedstocks (qv), such as natural gas, Hquefied petroleum gas, and naphtha, or in some cases heavier distillate oils are purified of sulfur compounds (see Sulfurremoval and recovery). These then react with steam in the presence of a nickel-containing catalyst to produce a mixture of hydrogen, methane, and carbon oxides. Essentially total decomposition of compounds containing more than one carbon atom per molecule is obtained (see Ammonia Hydrogen Petroleum). 

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