Paraffin, dehydrogenation

Future Developments. The most recent advance in detergent alkylation is the development of a soHd catalyst system. UOP and Compania Espanola de Petroleos SA (CEPSA) have disclosed the joint development of a fixed-bed heterogeneous aromatic alkylation catalyst system for the production of LAB. Petresa, a subsidiary of CEPSA, has announced plans for the constmction of a 75,000 t/yr LAB plant in Quebec, Canada, that will use the UOP / -paraffin dehydrogenation process and the new fixed-bed alkylation process (85). 

The mechanistic steps are as follows paraffins dehydrogenate to olefins the olefins oligomerize and cyclize and the cycHcs aromatize. Because the first step is rate controlling, very Httie olefin is actually present. The BTX product is relatively free of nonaromatics and therefore is very desirable as a chemical feed. As in reforming, some C —C2 fuel gas is produced along with a valuable hydrogen stream. Prom a C —feed the BTX product is roughly 35 45 20, respectively. 

Individual a-olefin feedstocks were purchased from Aldrich Chemical Company. The Ci0-Ci4 paraffin dehydrogenate was obtained from a commercial LAB plant and contained 8.5% Ci0-Ci4 olefins, primarily a mixture of internal olefins. 

Aromatic alkylation is illustrated in this paper for both individual a-olefin cuts (e.g. 1-decene and 1-dodecene) as well as typical samples of Ci0-Ci4 paraffin dehydrogenate that contain ca. 8.5% Go-Cm olefins, primarily internal olefins. Syntheses have, for the most part, been conducted in a continuous reactive distillation unit of the type illustrated in Figure 1, operated slightly above atmospheric pressure. Operational details for this unit may be found in the previous section. 

Figure 2 Benzene alkylation with C10-Ci4 paraffin dehydrogenate MF, using fluorinated mordenite catalyst M, using the non-fluorinated mordenite precursor.

Figure 3 Benzene alkylation with Ci0-Ci4 paraffin dehydrogenate catalyzed by fluorinated mordenite.

Paraffin dehydrogenation. Paraffin dehydrogenation gives exclusively internal alkenes. 

C10-C14 long paraffin dehydrogenation is a key-step for linear alkyl benzene (LAB) production. However, this reaction, which requires monofunctional catalysis, is implemented on Pt-Sn catalysts deposited on controlled acidity alumina. It is generally associated with several secondary reactions, among which aromatic formation is extremely problematic it is catalyzed by a metallic phase (M) or by residual support (A) activity. Indeed, on the one hand, these arylaromatics are very good coke precursors and are consequently responsible for a large part of the... 

Paraffin dehydrogenation, isomerization, and dehydrocyclization Paraffin cracking and isomerization Alcohol -> olefin + H20 Paraffin hydrocracking Olefin polymerization,... 

The statements of the possible role of HO radicals in saturated hydrocarbon oxidation processes is proved by experimentally determined formation of sufficient amounts of hydrogen peroxide and HO radicals during oxidation of propane [27] and paraffin dehydrogenation products [28-30],... 

C. Ercan, R. J. Gartside, Reactor Performance and Stability in an Alternating Reaction-Reheat Paraffin Dehydrogenation System. Can. J. Chem. Eng.,... 

The paraffins dehydrogenation on platinum-alumina catalysts proceeds with constant rate up to some time-on-stream after which a slow deactivation of the catalysts takes place Since relative changes of the catalyst activity ( characterized by reaction rate) are proportional to relative amounts of the deposited coke it can suppose that coke formation is the main reason of deactivation. Deactivation can be related with an attainment of a threshold in coke concentration (Co) on catalysts. The threshold amounts are 1.8 wt.% for A-I, 6,8% and 2.2% for A-II and A-IXI catalysts respectively. The isobutane dehydrogenation in non-stationary region (C > Co) is described by the following kinetic equation ... 

UOP Olefins, mixed Light paraffins Ught paraffin dehydrogenation to corresponding olefin 34 1998... 

Paraffin dehydrogenation on Cr. Al203 Cracking of gas oil Vinyl chlonde monomer formation ... 

Paraffin dehydrogenation for the production of olefins has been in use since the late 1930s. During World War II, catalytic dehydrogenation of butanes over a chro-mia-alumina catalyst was done for the production of butenes that were then dimerized to octenes and hydrogenated to octanes to yield high-octane aviation fuel. 

Paraffin dehydrogenation is an endothermic reaction that is limited by chemical equilibrium and, according to Le Chatelier s principle, higher conversion will require either higher temperatures or lower pressures. As noted earlier, the maximum equilibrium conversion in a simplified form can be approximated as follows ... 

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