Petroleum naphtha “reforming

Application The Sulfolane process recovers high-purity C6-C9 aromatics from hydrocarbon mixtures, such as reformed petroleum naphtha (reformate), pyrolysis gasoline (pygas), or coke oven light oil (COLO), by extractive distillation with or without liquid-liquid extraction. 

Platinum-alumina catalysts have been of profound importance in petroleum naphtha reforming and paraffin isomerization processes. Much information has been established concerning platinum crystallite size and interaction with the acidic support in terms of... 

A knowledge of the hydrocarbon components comprising a petroleum naphtha, reformate, or alkylate is useful... 

In the petroleum refining industry, hydrogen is essentially obtained from catalytic naphtha reforming, where it is a coproduct with reformed gasoline. 

The calorific value of this gas is too high for direct use as town gas (470-500 Btu/standard cubic foot in the United Kingdom) and too low for SNG, However, by removing the CO> the calorific value is increased to about 870 Btu/standard cubic foot, which is useful for enriching lean gas (e.g. from an Imperial Chemical Industries (IC1) naphtha reformer) to town gas quality. Long has suggested that by enriching this gas with LPG (liquefied petroleum gas) a satisfactory SNG may be obtained. 

Fig. 1.3. Reactor system of a petroleum naphtha catalytic reforming plant. (The reactor is divided into three units each of which operates adiabatically, the heat required being supplied at intermediate stages via an external furnace)...

The first two naphthas were run at 250 psig. The initial activity was very encouraging, but the activity decline was quite rapid. Since the reactor system was not provided with regeneration capability, the remainder of the naphthas were reformed at 500 psig. At that pressure, clean petroleum naphthas have been run for over 1000 hr with very little activity loss. 

A major portion of the world s BTX is made by naphtha reforming. The technology and economics of this route is well reported in petroleum refinery handbooks. Often this route uses extractive distillation to extract aromatics prior to distillation. Reforming operations are often integrated with ethylene cracking operations to maximise benzene production from reformate and pyrolysis gasoline. ... 

Figure 4-8 Sptiedcal Ultrafonrier Reactor. (Courtesy of Amoco Petroleum Products.) This reactor is one in a series of six used by Amoco for reforming petroleum naphtha. Photo by K. R. Renicker, Sr.

Interest in carbon deposition cm platinum surfaces has been driven by the fact that this metal and its alloys are used extensively in the reforming of petroleum naphthas. This reaction is carried out over bi-functional catalysts which consist of a single metal (e.g. Pt) or a combination of metals (e.g. Pt/Ir, Pt/Re, Pt/Sn) dispersed on an acidic support such as alumina, on which the acidity is controlled by addition of... 

The objective of the process is to convert saturated hydrocarbons (alkanes and cycloalkanes) in petroleum naphtha fractions to aromatic hydrocarbons as selectively as possible, since the latter have excellent antiknock ratings (1,2). Naphtha fractions are composed of hydrocarbons with boiling points in the approximate range of 50-200°C. Reaction temperatures of 425-525°C and pressures of 10-35 atm are employed in the process. Reforming catalysts commonly contain platinum (3-5) or a combination of platinum and a second metallic element such as rhenium (6) or iridium (2,7). 

The studies of n-heptane and methylcyclopentane conversion provide insight into the advantages of platinum-iridium and platinum-rhenium catalysts over catalysts containing only one of the transition metal components, that is, platinum, iridium, or rhenium. If, for example, we consider an iridium-alumina catalyst for the reforming of a petroleum naphtha fraction, we find that it produces a substantially higher octane number reformate than a platinum on alumina catalyst under normal reforming conditions. The iridium-alumina catalyst will also exhibit a lower rate of formation of carbonaceous residues on the surface, with the result that the maintenance of activity with time will be much superior to that of a platinum-alumina catalyst. 

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