Aromatization of propane

However, it was found that the effect on the equilibrium formation of aromatics is not substantial due to thermodynamic considerations. A more favorable effect was found for the reaction between ethylene (formed via cracking during aromatization of propane) and hydrogen. The reverse shift reaction consumes hydrogen and decreases the chances for the reduction of ethylene to ethane byproduct. 

Syoichi, Y. et ah, Aromatization of Propane in CO2 Atmosphere, Second Joint Saudi Japanese Workshop on Recent Developments in Selected Petroleum Refining and Petrochemical Processes, KFUPM, Dhahran, Saudi Arabia, 12-13, Dec. 1992. 

Choudhary, V.R., Kinage, A.K., and Choudhary, T.V. (1996) Simultaneous aromatization of propane and higher alkanes or alkenes over H-GaAlMEl zeolite. Chem. Commun., 2545-2546. 

Since it is now well accepted that the role of the additive in the H-ZSM-5 based catalysts is to Increase the rate of propane dehydrogenation it is clear that the additive should be sufficiently active to establish rapidly the thermodyneunic equilibrium propane-propene. Ga203 or ZnO exhibits with respect to Pt catalysts lower dehydrogenating properties. Nevertheless, when supported on H-ZSM-5, they were found to promote more efficiently the aromatization of propane, and also the... 

B. Activation and Aromatization of Propane on Solid Acid Catalysts... 

Fig. 2.1 Simplified reaction mechanism for the aromatization of propane on HZSM-5 and bifunctional (Ga, Zn, Pt)/HZSM-5 catalysts...

Application To produce petrochemical-grade benzene, toluene and xylenes (BTX) via the aromatization of propane and butanes using the BP-UOP Cyclar process. 

S. Uemiya, T. Matsuda, and E. Kikuchi, Aromatization of propane assisted by palladium membrane reactor, Chem, Lett, No. 8, 1335 (1990). 

Gallosilicate Catalysts. Aromatization of Propane and Butane. Cyclar Process. The Cyclar process, which was discovered by BP and jointly developed with UOP, uses a single catalyst system to convert propane and butanes into aromatic hydrocarbons at high selectivity. The catalyst consists of a zeolite with a non-noble metal promoter. The zeolite component provides a shape-selective acid function, and the non-noble metal additive acts as a dehydrogenation catalyst. ... 

The aromatization of propane and butanes is a thermodynamically feasible endothermic reaction (35-45 Kcal/mole). Aromatization in the Cyclar process includes a series of distinct reaction steps, including dehydrogenation, olefin oligomerization, cyclization, hydrogen transfer, alkylation, dealkylation, and cracking. 

The aromatization of propane on supported (Si02/Al203)Ga, Zn or Pt catalysts is limited due to hydrocracking, dealkylation and hydrogen transfer reactions which lead to the formation of methane and ethane as the major products, and ethene and propene. However, the use of a Pd membrane reactor increases the yield of aromatics (e.g. benzene, toluene, Cg-Ci2 aromatics) dramatically by effective separation of the produced hydrogen gas from the reaction mixture by utilizing the H2 permeability of Pd thin films. 

Figure 3.53 Flow diagram of the Cyclar process for aromatization of propane/butane...

Araujo LRR, Schmal M. The calcination effects on Pt/HZSM-5 catalysts in the aromatization of propane. Appl Catal A. 2000 203(2) 275. 

Buckles G, Hutchings GJ, Williams CD. Aromatization of propane over Ga/HZSM-5 an explanation of the synergy observed between Ga + and H+. Catal Lett 1991 11 89-94. 

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