Catalysis by zeolites - active sites, kinetics, mechanisms

Conference · Wed Jun 01 04:00:00 EDT 1988 · American Chemical Society, Division of Petroleum Chemistry, Preprints; (USA)

OSTI ID:5238024

Haag, W O ^[1]

---

1. Mobile Research and Development Corporation, Princeton, NJ (USA)

In the past twenty five years, zeolites have become very important catalysts for the petroleum and petrochemical industry as a result of their high activity and shape selectivity. They have also enabled us to gain new insight into fundamental aspects of acid catalysts and to rationally design new catalysts. In contrast to large pore zeolites such as faujasite and mordenite, medium pore zeolites such as ZSM-5 exhibit very much lower catalyst deactivation rates. Our studies indicate that this is largely a consequence of their much lower activity for hydrogen transfer as a result of steric inhibition of this bimolecular reaction. High SiO{sub 2}/Al{sub 2}O{sub 3} zeolites can be prepared with well-defined catalytic sites of uniform activity whose number can be changed over four orders of magnitude. The most striking feature of zeolite catalysis is that of shape selectivity. It can result from the relative diffusion rates of various feed and product molecules or from a steric constraint of the reaction transition state. The distinction between the cause of an observed shape selectivity is of fundamental interest and has important consequences for catalyst design. Using medium pore zeolites we have identified a novel olefin interconversion reaction which equilibrates olefins to a pseudo-equilibrium mixture of all carbon numbers with a minimum of side reaction, and have elucidated its mechanism. A new process for the conversion of light olefins to gasoline, jet fuel and distillates has been developed based on this discovery.

• OSTI ID: 5238024
• Report Number(s): CONF-8806304--
• Conference Information: Journal Name: American Chemical Society, Division of Petroleum Chemistry, Preprints; (USA) Journal Volume: 33:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
020500 -- Petroleum-- Products & By-Products
CATALYSIS
CATALYSTS
CATALYTIC CRACKING
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
DIFFUSION
DOCUMENT TYPES
EQUILIBRIUM
FUELS
GASOLINE
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
JET ENGINE FUELS
KINETICS
LIQUID FUELS
MATERIALS
MINERALS
PETROLEUM PRODUCTS
PRODUCTION
PYROLYSIS
REACTION KINETICS
REVIEWS
THERMOCHEMICAL PROCESSES
ZEOLITES