Naphtha reforming catalyst

Most catalyst supports are simply nearly inert platforms that help stabilize the dispersion of the catalyticaHy active phase. Sometimes, however, the supports play a direct catalytic role, as exemplified by the alumina used in supported Pt and RePt catalysts for naphtha reforming. 

Powerforming is one tecnique used for aromatics chemical production. Powerforming uses a platinum catalyst to reform virgin naphthas. The principal reaction is the conversion of naphthenes in virgin naphthas to aromatics e.g., isomerization and dehydrocyclization reactions also occur in catalytic reforming. 

Catalytic processes frequently require more than a single chemical function, and these bifunctional or polyfunctional materials innst be prepared in away to assure effective communication among the various constitnents. For example, naphtha reforming requires both an acidic function for isomerization and alkylation and a hydrogenation function for aromati-zation and saturation. The acidic function is often a promoted porous metal oxide (e.g., alumina) with a noble metal (e.g., platinum) deposited on its surface to provide the hydrogenation sites. To avoid separation problems, it is not unusual to attach homogeneous catalysts and even enzymes to solid surfaces for use in flow reactors. Although this technique works well in some environmental catalytic systems, such attachment sometimes modifies the catalytic specifici-... 

Supported bimetallic catalysts find many industrial applications. Examples include Pt and Rh in automobile exhaust conversion catalysts and Pt and Re (or Pt and Sn or Pt and Ir) in naphtha reforming catalysts. 

X. H. Ren, M. Bertmer, H. Kuhn, S. Stapf, D. E. Demco, B. Blumich, C. Kem, A. Jess 2002, ( H, 13C and 129Xe NMR study of changing pore size and tortuosity during deactivation and decoking of a naphtha reforming catalyst), NATO Sci. Ser. ITMath., Phys. Chem. 7b, 603. 

Butanol over Naphtha Reforming Type Catalysts in Conventional and High Throughput Slurry Phase Reactors... 

In this study butyl acetate (AcOBu) was hydrogenolysed to butanol over alumina supported Pt, Re, RePt and Re modified SnPt naphtha reforming catalysts both in a conventional autoclave and a high throughput (HT) slurry phase reactor system (AMTEC SPR 16). The oxide precursors of catalysts were characterized by Temperature-Programmed Reduction (TPR). The aim of this work was to study the role and efficiency of Sn and Re in the activation of the carbonyl group of esters. 

In addition to natural gas, steam reformers can be used on light hydrocarbons such as butane and propane and on naphtha with a special catalyst. Steam reforming reactions are highly endothermic and need a significant heat source. Often the residual fuel exiting the fuel cell is burned to supply this requirement. Fuels are typically reformed at temperatures of 760 to 980°C (1,400 to 1,800°F). 

Introduction of zeolites into catalytic cracking improved the quality of the product and the efficiency of the process. It was estimated that this modification in catalyst composition in the United States alone saved over 200 million barrels of crude oil in 1977. The use of bimetallic catalysts in reforming of naphthas, a basic process for the production of high-octane gasoline and petrochemicals, resulted in great improvement in the catalytic performance of the process, and in considerable extension of catalyst life. New catalytic approaches to the development of synthetic fuels are being unveiled. 

The Pt-Re system has been studied extensively since the 1970s because adding Re to AhOs-supported platinum catalysts increases the resistance to deactivation of the catalysts used in naphtha reforming by preventing coke deposition. By using carbonyl precursors, well-defined bimetalhc species have been prepared. A proper characterization of these species allowed a relationship to be established between their structure and their catalytic behavior. Table 8.3 shows several Pt-Re bimetaUic catalytic systems prepared using different carbonyl species in which Pt-Re interactions determine the catalytic behavior. 

A similar study reports the results of adding 100 ppm thiophene to As in the Palm et al. study,the catalyst is not described rather, it is identified only as a commercial naphtha reforming catalyst, presumably Pt-based. In their reactor, the reformate from the ATR step passes through separate high and low temperature shift reactors before being analyzed. Thus, it was not possible to determine the effect of sulfur on the reforming step alone, nor was any post-reaction characterization of the catalyst reported, for example to determine coke or sulfur content. Figure 16 shows the observed deactivation, as measured by a decrease in H2 and CO concentrations. 

Figure 16 Deactivation of a naphtha reforming catalyst in the reforming of i-Cg feed 100...

Moon et alP studied the ATR of i-Cg over a commercial naphtha reforming catalyst that is not further identified (presumably a Pt-based... 

As seen in Figure 2.2 and from the corresponding discussion, dehydrocyclization is a key reaction in forming aromatic compounds.307 A study comparing dehydrocyclization over mono- and bifiinctional catalysts at atmospheric pressure and high pressure representative of naphtha reforming conditions concludes that primary aromatic products at all pressures are formed by direct six-carbon ring formation.313 Over bifunctional catalysts the acid-catalyzed cyclization is more rapid... 

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