Reforming catalytic steam

CSR has been applied mainly to hydrocarbons, especially methane. It is the most mature and the best established technology for hydrogen production. The process is endothermic and therefore a significant fuel penalty must be paid to provide the needed heat. 

Steam reforming for an oxygenated compound with a generic chemical formula C H 0( proceeds according to the following equation  

The water gas shift reaction (WGSR) (Equation 6.2), which occurs simultaneously, constitutes an integral part of the reforming process  

If both reactions (Equations 6.1 and 6.2) go to completion, the overall process can be expressed by Equation 6.3  

These reactions, which occur in parallel with reforming, produce carbonaceous deposits resulting in catalyst deactivation and in lower yields of hydrogen. 

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Synthesis Gas Chemicals. Hydrocarbons are used to generate synthesis gas, a mixture of carbon monoxide and hydrogen, for conversion to other chemicals. The primary chemical made from synthesis gas is methanol, though acetic acid and acetic anhydride are also made by this route. Carbon monoxide (qv) is produced by partial oxidation of hydrocarbons or by the catalytic steam reforming of natural gas. About 96% of synthesis gas is made by steam reforming, followed by the water gas shift reaction to give the desired H2 /CO ratio. 

In the catalytic steam reforming of natural gas (see Fig. 2), the hydrocarbon stream, principally methane, is desulfurized and, through the use of superheated steam (qv), contacts a nickel catalyst in the primary reformer at ca 3.04 MPa (30 atm) pressure and 800°C to convert methane to H2. 

The catalytic steam-reforming process of methanol on Cu/ZnO/Ab03 catalyst primarily produces hydrogen and carbon dioxide. In addition, the minor quantities of carbon monoxide are also produced. This mechanism is explained in terms of parallel reactions [11]. 

Several other important commercial processes need to be mentioned. They are (not necessarily in the order of importance) the low pressure methanol process, using a copper-containing catalyst which was introduced in 1972 the production of acetic add from methanol over RhI catalysts, which has cornered the market the methanol-to-gasoline processes (MTG) over ZSM-5 zeolite, which opened a new route to gasoline from syngas and ammoxidation of propene over mixed-oxide catalysts. In 1962, catalytic steam reforming for the production of synthesis gas and/or hydrogen over nickel potassium alumina catalysts was commercialized. 

J.R. Rostrup-Nielsen, Catalytic Steam Reforming , Catalysis, Science and Technology, vol. 5, p.l, J.R. Anderson and M. Boudan, (Eds.), Springer, Berlin, 1984. 

The diverse sources for hydrogen are depicted in Figure 6.1.6 Today, the least expensive and the most widely applied technology to produce hydrogen is catalytic steam reforming... 

Aznar, M. P. Caballero, M. A. Corella, J. Molina, G. Toledo, J. M., Hydrogen production by biomass gasification with steam-02 mixtures followed by a catalytic steam reformer and a CO-Shift system. Energy and Fuels 2006, 20, 1305-1309. 

Czernik, S. French, R. Feik, C. Chomet, Ev Hydrogen by catalytic steam reforming of liquid byproducts from biomass thermoconversion processes, Industrial and Engineering Chemistry Research 2002,41,4209. 

MRG [Methane rich gas] A catalytic steam-reforming system, similar to the classic syngas reaction of steam with a hydrocarbon mixture, but yielding hydrogen, methane, and carbon monoxide in different proportions. The system is thermodynamically balanced,... 

Recatro A process for making gas from liquid fuels and other gaseous hydrocarbons by catalytic conversion into rich gas, followed by catalytic steam reforming. Developed by BASF and Lurgi. 

The oil can be formed in 66 wt% yields. Catalytic steam reforming of bio-oil at 750 to 850°C over a nickel-based catalyst is a two-step process that includes the shift reaction ... 

Demirbas, A. and Caglar, A. (1998). Catalytic Steam Reforming of Biomass and Heavy Oil Residues to Hydrogen, Energy Edu. Sci. Technol 1. pp. 45-52. 

Catalytic reformates, 13 703 25 168 Catalytic reformers, 13 557 aromatics from, 13 565 effluent separation from, 20 750 Catalytic reforming, 12 403 13 657-658 benzene manufacture, 3 604-606 as a source of toluene, 25 166 Catalytic silver sulfate, 23 536 Catalytic steam reforming reaction,... 

Garcia, L., French, R., Czemik, S., Chornet, E., Catalytic steam reforming of bio-oils for the production of hydrogen effects of catalyst composition, Appl. 

M. Mann, E. Chorlet, in Hydrogen production via catalytic steam reforming of fast pyrolysis oil fractions. Proceedings of the 3ri Biomass Conference of the Americas, Pergamon, Oxford, 1997, p. 845. 

Methanol is unquestionably the easiest of the potential fuels to convert to hydrogen for vehicle use. Methanol disassociates to carbon monoxide and hydrogen at temperatures below 400°C and can be catalytically steam reformed at 250°C or less. This provides a quick start advantage. Methanol can be converted to hydrogen with efficiencies of >90 %. But methanol is produced primarily from natural gas requiring energy and it is less attractive than gasoline on a well-to-wheels efficiency (2). 

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

Hydrogen production by partial oxidation is similar to production by catalytic steam reforming. The process basically involves the conversion of steam, oxygen and hydrocarbons to hydrogen and carbon oxides. The process proceeds at moderately high pressures with or without a catalyst depending on the feedstock and process selected. The catalytic POX, which occurs at about 865 K, will work with feedstock ranging from methane to naphtha. The non-catalytic POX, which occurs... 

Rostrup-Nielsen, J.R. 1984. Catalytic steam reforming, in Catalysis science and technology, Vol. 5, J.R. Anderson, M. Boudart. Springer, Berlin Heidelberg New York, pp. 1-117. 

In this ideahzed, stoichiometric equation (Eq. 6.36), cellulose (represented as CjHj Oj) reacts with water to produce and CO, the conunercial production of Hjfrom methane by the catalytic steam reforming process (Wagner and Froment, 1992). 

Chomet, E. 2001. Biomass to hydrogen via fast pyrolysis and catalytic steam reforming. Proceedings of the 2001 USA. DOE Hydrogen Program Review (NREL/CP 570-30535). 

Wang, D., Czernik, S., Chornet, E. 1998. Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oils. Energy Fuels 12 19-24. 

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