Reformer naphtha feedstocks

Hydrocarbon feedstocks for steam reformers include natural gas, refinery gas, propane, LPG and butane. Naphtha feedstocks with boiling points up to about 430°F can also be used. The ideal fuels for steam reformers are light hydrocarbons such as natural gas and refinery gas, although distillate fuels are also used. Residual fuels are not used since they contain metals that can damage reformer tubes. 

Naphtha to become a suitable component tor blending into finished gasoline pools must be further processed. The octane number will range from 40 to 50. Prior to introduction into a catalytic-reforming unit, most naphtha feedstocks are hydrotreated in the interest of prolonging the life of the reforming catalyst. 

Generally, hydrodesulfurization of naphtha feedstocks to produce catalytic reforming feedstocks is carried to the point where the desulfurized feedstock contains less than 20 ppm sulfur. The net hydrogen produced by the reforming operation may actually be sufficient to provide the hydrogen consumed in the desulfurization process. 

Thus a variety of hydrocarbons, ranging from natural gas to coal, are used in methanol production. Regardless of the feedstock used to prepare the synthesis gas, it is necessary to remove sulfur so that the converter catalyst is not poisoned. Before natural gas or naphtha is reformed, the feedstock is desulfurized. In the partial oxidation and coal gasification processes, the feedstock is first oxidized and the resulting synthesis gas is desulfurized before entering the converter. 

Results showed that the two-stage TCH process could be used for upgrading Athabasca bitumen and for producing reformer naphtha feedstock, fuel oils, and catalytic cracking gas-oil feedstock. Product weight yields ranging from 86.4% to 93.0% were obtained. A 3 wt % CoO-15 wt % Mo03 on alumina catalyst was found to be sufficiently active to produce specification distillates. Comparison of various catalysts showed some differences in selectivities. However, extended life studies should be carried out to substantiate the differences. 

Krupp Udhe Methanol Natural gas, LPG and heavy naphtha Steam reforming process cost-effectively manufactures methanol from varying feedstocks 11 NA... 

The steam reforming of hydrocarbon feedstocks is a common industrial process which produces hydrogen for use in methanol or ammonia synthesis. A variety of hydrocarbons, e.g. natural gas or naphthas, can be used as the reactant in the steam reforming process, This use of a variety of reactant feed types places considerable demands upon the catalyst manufacturer since all hydrocarbons have different reactivities and, most importantly, disparate tendencies to generate carbonaceous deposits, ICI produce a range of catalysts for use with a number of hydrocarbon reactants. For the reforming of heavy naphtha feedstocks, which show a considerable propensity for carbon deposition, ICI provides a potassium promoted nickel based catalyst (ref 1). The object of this paper is to describe the mechanism by which alkali provides resistance to carbon formation in nickel catalysts. 

Carbon deposition is one of the luost serious problems of the steam reforming catalyst process (ref 1). The deposition of carbon on naphtha steam reforming catalysts depends ori the chemical composition of the hydrocarbon oil, the steam/carbon ratio in the feedstock, as well as the pi ocesa temperature and pressure, it is also affected by tlie presence of sulfur poisons Our past research of SNG catalysts ejiamined the nature of the carbon deposits as a function of the sulfur level on the catalyst (refs, 2 4). A small amount of sulfur was found to promote the formation of carbon that is non-reactive with steam and hydrogen under steam reforming reaction conditions. The continuous accumulation of this less reactive carbon [continuous carbon deposition (CCD)l on the catalyst surface leads to coke fouling Studies of the occurrence of CCD in our laboratory tests allow ua to predict, that coke fouling is likely to occur on the same catalyst used in real Indusl.rlal applications. 

Both clean and sulfur-poisoned catalysts were then used in 24 and 166 hour steam reforming runs at. 490 C and 25 atm with a sulfur-free naphtha feedstock. The experimental apparatus consists of a fixed bed microreactor made of stainless steel for high pre Esure runs. During each run, the catalyst activity was monitored by analyzing the reactor effluent using an on-line quadrupolc mass spectrometer as well as by gas chromatography ... 

These catalysts have to fulfil new safety requirements as they may be operated in the consumer s home, and also will experience a very different duty cycle than industrial catalysts. Another field that has attracted interest is sulfur tolerant shift catalysts. Catalysts have been developed for high sulfur concentrations in the feed gas since the 1960s, but have not found large-scale application up to the present. The fact is that most ammonia, methanol, and hydrogen plants are based on natural gas or naphtha feedstocks, which have relatively low content of sulfur-containing compounds, and therefore do not require these more expensive catalysts. HDS is typically used to reduce sulfur levels in the feed gas to ppm to ppb levels to protect the steam reforming and downstream catalysts. 

A typical catalytic reforming unit consists of a number of fixed-bed reactors, frequently four, in series. The naphtha feedstock is vaporized and heated to the desired reaction temperature, then admitted to the first reactor. As the components in the naphtha undergo reaction during passage through the catalyst bed, the temperature of the vapor stream decreases by 70-100 C due to the endothermicity of the reaction. The major reaction occurring in the first catalyst bed is the dehydrogenation of cycloalkanes to aromatics. 

The carbon deficit observed in methane steam reforming does not occur if naphtha feedstock is converted. In autotheimal processes using fuel oil as a feedstock, sufficient quantities of excess carbon dioxide are available within the installation itself. This gas is recycled from a scrubbing unit. 

The reforming units typically consist of three or four fixed-bed adiabatic reactors in series. The naphtha feedstock is vaporized and heated to the reaction temperature and mixed with hydrogen before it enters the first reactor. 

Feedstock Composition. Feedstock to a reformer typically contains paraffins, naphthenes, and aromatics ranging in the number of carbon atoms from six to twelve. Feedstocks to a reformer are typically called naphthas. These naphthas are reformed to produce high octane motor fuels or aromatics for petrochemical applications. A description of the sources of naphtha is given, followed by a more detailed description of naphtha s chemical composition, analytical characterization, and reactions. Most naphthas are treated in a process called... 

Typical hydrocarbon feedstocks for the reformer include natural gas, refinery gas, propane, LPG, and butane. Naphtha feedstocks with final boiling points up to about 430°F can also be processed. 

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