Catalytic reforming conditions

Thermodynamic data for Ce hydrocarbon reactions under catalytic reforming conditions are summarized in Table 3.20. 

The predominant feeds for reforming are straight-mn naphthas from cmde stills. Naphthas from catalyst crackers and naphthas from code stills are also used. Typical compositions are summarized in Table 5. Typical operating conditions for catalytic reforming are 1.135—3.548 MPa (150—500 psi),... 

C, 0.356—1.069 m H2/L (2000—6000 fU/bbl) of Hquid feed, and a space velocity (wt feed per wt catalyst) of 1—5 h. Operation of reformers at low pressure, high temperature, and low hydrogen recycle rates favors the kinetics and the thermodynamics for aromatics production and reduces operating costs. However, all three of these factors, which tend to increase coking, increase the deactivation rate of the catalyst therefore, operating conditions are a compromise. More detailed treatment of the catalysis and chemistry of catalytic reforming is available (33—35). Typical reformate compositions are shown in Table 6. 

A catalytic reforming process produces similar products. The relative amounts may differ, however, depending on the catalyst selectivity and process conditions, the main product, of course, is a high octane C, -1- gasoline fraction. 

Where two numbers are given, the first number represents average operating conditions while the second number represents maximum operating conditions. Catalytic reformer service. 

Figure 2 shows the microstructure of a sample of C-0.5Mo steel damaged by internal decarburization and Assuring. The service conditions were 790°F (421°C) at a hydrogen partial pressure of 425 pounds per square inch absolute (2.9 megapascals) for approximately 65,000 hours in a catalytic reformer. 

The first step is relevant to the start-up phase, which in this particular case we chose to extend for up to 1 h in order to verify the reactor stability also in these conditions, where water is not present and while there is a higher oxygen concentration in the feed gas with respect to the ATR conditions. By lowering the 02 CH4 ratio, the H2 concentration at the reactor outlet increases, approaching the value expected by thermodynamic evaluation and CH4 conversion is still complete. A further decrease in the 02 CH4 feed ratio to values lower than 1.16 corresponds to an abrupt decrease in temperature in the lower section and a simultaneous temperature increase in the catalytic reforming section. 

SR of ethanol has mainly been conducted under similar conditions as methane SR, which means relatively high temperatures, ambient pressure, and primarily with Ni- or Rh-based catalysts." Ideally, one mole of ethanol is converted into 6 moles of hydrogen (13). During SR, ethanol decomposes mainly through two different routes either by dehydrogenation to acetaldehyde (14) or dehydration to ethylene (15). These two intermediates can be further catalytically reformed to a thermodynamically equilibrated reaction mixture of H2, CO, CO2, CH4 and H2O (12, 16-18). ... 

The conversion of cyclohexanes to aromatics is a highly endothermic reaction (AH 50 kcal./mole) and occurs very readily over platinum-alumina catalyst at temperatures above about 350°C. At temperatures in the range 450-500°C., common in catalytic reforming, it is extremely difficult to avoid diffusional limitations and to maintain isothermal conditions. The importance of pore diffusion effects in the dehydrogenation of cyclohexane to benzene at temperatures above about 372°C. has been shown by Barnett et al. (B2). However, at temperatures below 372°C. these investigators concluded that pore diffusion did not limit the rate when using in, catalyst pellets. 

The amount of xylenes contained in the catalytic reformate depends on the fraction and type of crude oil, the reformer operating conditions, and the catalyst used. The amount of xylenes produced can vary widely, typically... 

This paper presents a simulation of coke burning valid for all inlet conditions, and capable of handling any sequence of switches in these conditions. Sample results are presented for conditions of interest in catalytic reforming. 

Without a doubt, a complete picture of the dynamics of dissociative chemisorption and the relevant parameters which govern these mechanisms would be incredibly useful in studying and improving industrially relevant catalysis and surface reaction processes. For example, the dissociation of methane on a supported metal catalyst surface is the rate limiting step in the steam reforming of natural gas, an initial step in the production of many different industrial chemicals [1]. Precursor-mediated dissociation has been shown to play a dominant role in epitaxial silicon growth from disilane, a process employed to produce transistors and various microelectronic devices [2]. An examination of the Boltzmann distribution of kinetic energies for a gas at typical industrial catalytic reactor conditions (T 1000 K)... 

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