Degenerate non-primary products in catalytic cracking of isoalkanes

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1074· OSTI ID:7036606

Kissin, Y V ^[1]

---

1. Gulf Research and Development Company, Pittsburgh, PA (United States)

Product distributions in catalytic cracking of a series of C[sub 10]-C[sub 17] isoalkanes over two acidic catalysts, a Y-zeolite-based commercial catalyst and SiO[sub 2]-Al[sub 2]O[sub 3], were studied at 250 and 350[degrees]C. The cracked products from a C[sub n] alkane belong to two distinct groups, primary products (isomerized C[sub n] alkanes) and degenerate nonprimary products, isoalkanes ranging from C[sub 3] to C[sub n[minus]1]. Degeneration of the non-primary products is expressed in two ways: 1. In each carbon number range, the non-primary products from alkanes are the mixtures of isoalkanes containing mostly monomethyl- and dimethyl-branched alkanes. The compositions of the mixtures are practically independent of the structures of feed alkanes, and the relative yields of isoalkanes with different skeletons are mostly determined by the thermodynamic stabilities of respective isomers. 2. The distributions of the non-primary products with respect to their carbon numbers have the inverted-U shapes with the maxima at C[sub 4]-C[sub 5]. These distributions also do not depend on the skeleton structure of the feeds. The main reason for the cracked product degeneration is high reactivity of a part of the reaction products, light olefins, in reactions over acidic catalysts. This conclusion is based on the experimental cracking study of a series of C[sub 3]-C[sub 14] olefins with the same catalysts under mild conditions (100-250[degrees]C). 25 refs., 6 figs., 6 tabs.

• OSTI ID: 7036606
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 146:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKENES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
HETEROGENEOUS CATALYSIS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOMERIZATION
MATERIALS
MINERALS
ORGANIC COMPOUNDS
PYROLYSIS
SILICATE MINERALS
THERMOCHEMICAL PROCESSES
ZEOLITES