Catalytic Reforming Objective

Figure 7.10 An aerial view of a catalytic reforming processing plant. The reactors are the 21-ft spherical objects in the middle. These contain platinum and are in a series so that the octane is increased a little more in each reactor. (Courtesy of BP Amoco, Texas City, TX)...

In the first group, the production of aromatics is a complementary objective to the refinery processing of gasoline fractions to raise the aromatic content, which evidently links these refining functions. Catalytic reforming processes are used to convert paraffins to naphthenes (cycloparaffins) to be followed by dehydrogenation of naphthenes to aromatics (Chap. 18). Since aromatization of naphthenes is an easier process to accomplish than cycloalkylation, the emphasis in refinery operations is on maximization of the second step in this sequence, when there is an adequate supply of naphthenes. The demand for the aromatics component of gasoline will compete with the feedstock aromatic need from this source. 

There are situations where support acidity has a positive influence, influencing the main reaction. The support adds dual functionality to the overall catalysis, as best demonstrated with catalytic reforming/ The objective in this process is to convert low octane components of naphtha, typically normal paraffins and naphthenes, into high-octane iso-parafHns and aromatics. Low loadings of Pt type metals on AljOj are used for this purpose. Metallic Pt dehydrogenates naphthenes to aromatics but cannot isomerize or cyclize normal paraffins. This is accomplished through the acidic function of the support, as shown for n-hexane ... 

The objectives of the catalytic reforming of naphtha are to increase the naphtha octane number (petroleum refination) or to produce aromatic hydrocarbons (petrochemistry). Bifunctional catalysts that promote hydrocarbon dehydrogenation, isomerization, cracking and dehydrocyclization are used to accomplish such purposes. Together with these reactions, a carbon deposition which deactivates the catalyst takes place. This deactivation limits the industrial operation to a time which depends on the operational conditions. As this time may be very long, to study catalyst stability in laboratory, accelerated deactivation tests are required. The knowledge of the influence of operational conditions on coke deposition and on its nature, may help in the efforts to avoid its formation. 

The stripper was operated with these two objectives in mind. However, the lab test showed the C5 component distribution. The stripper bottom contained 2mol% C5, which exceeds the targeted C5 removal from the bottom, which is undesirable. Two negative results were observed. Because C5 is not involved in the catalytic reforming reaction, C5 material not only occupied the space in the reactor and hence reduced reaction throughput, but also consumed extra heat in the feed heater for the reforming reactors. 

Table 3 presents a list of feeds and product objectives for different kinds of hydrotreaters and hydroeraekers. In the 1950s, the first hydrotreaters were used to remove sulfur from feeds to catalytic reformers. In the 1960s, the first hydrocrackers were built to convert gas oil into naphtha. 

For hydroprocessing units, product specifications are set to meet plantwide objectives. For example, the naphtha that goes to catalytic reforming and isomerization units must be (essentially) sulfur free. Before it can be sold as... 

A number of catalytic processes in current use make use of these strategies including reforming, isomerization, dimerization, alkylation and fluid catalytic cracking (FCC). The object of this paper is to discuss the catalytic strategies available to produce octane in the FCC unit. 

One of the initial attempts of exhaust gas reforming, as well as onboard H2 generation, was reported by Newkirk and Abel. Their process of high-temperature, non-catalytic SR of gasoline resulted in carbon formation in the reformer however, their objective, to reduce emissions by feeding H2 to the gasoline engine, was achieved. 

The selective oxidation or preferential oxidation of CO in hydrogen-rich stream is another important object for ceria based catalysts. The gas mixture from steam reforming/partial oxidation of alcohols or hydrocarbons, followed by the WGS reaction contains mainly FI2, CO2 and a small portion of CO, H2O, and N2. When such gaseous stream would be taken as input for hydrogen fuel cells, the CO has to be removed to avoid poisoning of the anode electrocatalysts. Ceria based nanomaterials, such as ceria/gold, ceria/copper oxide catalysts exhibit suitable catalytic activities and selectivities for CO PROX process. 

The objective of this book is to serve as a practical reference work on testing for the main hydrocarbon-conversion processes applied in oil refineries catalytic cracking, hydroprocessing, and reforming. These fields were combined because of the clear analogies and congruence between the areas, such as deactivation of active sites by coke, mass-transfer phenomena of hydrocarbons into solid catalysts, hydrocarbon chemistry and reaction kinetics, and downscaling of commercial conditions to realistic small-scale tests. 

Among the several catalysts tested in methane reforming with CO2, the Pt/Zr02 catalyst yields good results of activity and stability. The objective is to determine the catalytic activity of the Pt/Zr02 systems in different experimental conditions. 

Fluid-solid MSR have been extensively used particularly for gas-solid reactions such as catalytic partial oxidations, selective hydrogenations, dehydrogenations, dehydrations, and reforming processes [57, 58]. Similarly to the other reactions carried out in MSR, the main objective was to achieve better temperature control in order to prevent selectivity loss, catalyst deactivation, hot spot formation and, thus, allowing safe processing with high throughput. 

---