Hydrocarbon catalytic partial

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

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. 

Non-catalytic partial oxidation (POX) of hydrocarbons from residual fuel oils to methane is commercially proven by two processes, one offered by Texaco and the other by Shell. Davy has experience with both processes. Each process has a large number of plants in operation, with feeds varying from natural gas to high sulfur residual oil. (In fact, so long as the feedstock can be pumped, it is a suitable feestock for a partial oxidation gasifier. 

The catalytic partial pressures and temperatures used were thus simiLar to those employed by Boudart and were therefore expected to result in structure insensitivity- However, the hydrocarbon overlayer on the catalyst surfaces was also expected to exceed monolayer coverage In the light of previous results and it was recognised that this might be amportant ... 

Ceramic Membranes for Oxygen Separation and Catalytic Partial Oxidation of Hydrocarbons... 

Gardner et al. reported that H2S catalytic partial oxidation technology with an AC catalyst is a promising method for the removal of H2S from fuel cell hydrocarbon feedstocks.206 Three different fuel cell feedstocks were considered for analysis sour natural gas, sour effluent from a liquid middle distillate fuel processor, and a Texaco 02-blown coal-derived synthesis gas. Their experimental results indicate that H2S concentration can be removed down to the part per million level in these plants. Additionally, a power-law rate expression was developed and reaction kinetics compared with prior literature. The activation energy for this reaction was determined to be 34.4 kJ/g mol with the reaction being first order in H2S and 0.3 order in 02. 

Several processes, including noncatalytic partial oxidation (POX), catalytic partial oxidation (CPO), and ATR may be used to perform partial oxidation of hydrocarbons. In all cases, some or all of the reactions listed in Table 4 are involved. Normally, these reactions are accompanied by the steam-reforming and shift reactions. The oxidation reactions are irreversible at all conditions of practical interest. 

Catalytic partial oxidation of hydrocarbons represents an important class among petrochemical reactions. Complete oxidation of hydrocarbons gives CO2, H2O. During the partial oxidation processes the conversion of a certain percentage of reactants and/or products to complete combustion products cannot be avoided. The main role of the catalyst in these reactions is to accelerate (at relatively lower temperatures) the reaction paths to the desired product without having the same effect on the paths to the complete combustion products. The partial oxidation reactions are usually consecutive or consecutive/parallel reactions with quite complex networks in many cases. 

Catalysts with perovskitic structure guarantee a good compromise between stability and activity and have a relatively low cost, so they can constitute a valid alternative to supported noble metals, with particular reference to the reactions of partial or total oxidation of hydrocarbons (catalytic combustion). The traditional route used to synthesize perovskites was first introduced by Delmon and co-workers in the late nineteen sixties [1]. It enables to obtain i) mixed oxides over a wide range of composition ii) good control of the stoichiometry iii) an excellent interspersion of the elements in the final product iv) very small grain size materials. 

Palladium membranes have been known for years, and the concept of a membrane reactor that would allow the continuous removal of a reaction product from an equilibrium controlled reactor has been discussed and to some degree practiced for several decades. Hydrogen production, via some type of hydrocarbon reforming or catalytic partial oxidation, coupled with the WGS reaction CO -I- H2O H2 -I- CO2 (AG° = -41 kJ/mole) is one application for such a membrane reactor. 

Ahmed, S. (1998), Catalytic Partial Oxidation Reforming of Hydrocarbon Fuels, 1998 Fuel Cell Seminar, California, p. 242, Elsevier, N.Y. 

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. 

Foams were proved to be highly suitable as catalytic carrier when low pressure drop is mandatory. In comparison to monoliths, they allow radial mixing of the fluid combined with enhanced heat transfer properties because of the solid continuous phase of the foam structure. Catalytic foams are successfully used for partial oxidation of hydrocarbons, catalytic combustion, and removal of soot from diesel engines [14]. The integration of foam catalysts in combination with microstructured devices was reported by Yu et al. [15]. The authors used metal foams as catalyst support for a microstructured methanol reformer and studied the influence of the foam material on the catalytic selectivity and activity. Moritz et al. [16] constructed a ceramic MSR with an inserted SiC-foam. The electric conductive material can be used as internal heating elements and allows a very rapid heating up to temperatures of 800-1000°C. In addition, heat conductivity of metal or SiC foams avoids axial and radial temperature profiles facilitating isothermal reactor operation. 

A new horizon in S3mthesis gas production may be the process of catalytic partial oxidation (CPO) (59-61), of hydrocarbons, for example, the selective oxidation of methane... 

Finally catalytic partial dehydrogenation of hydrocarbon fuels should be mentioned as an alternative to complete conversion in reforming processes. Platinum catalysts eventually doped with tin seem to be well suited for this reaction. However, stability issues still require further investigations as indicated by the work of LucarelU et al. [48]. 

Newson, E. and Truong, T.B. (2003) Low-temperature catalytic partial oxidation of hydrocarbons (Cj—Cjo) for hydrogen production. Int. J. Hydrogen Energ., 28, 1379-1386. 

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