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The kinetics of alkylation of isobutane with propylene
Author(s) -
Langley J. Randolph,
Pike Ralph W.
Publication year - 1972
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690180406
Subject(s) - isobutane , sulfuric acid , arrhenius equation , chemistry , carbonium ion , catalysis , reaction rate constant , alkylation , reaction mechanism , rate equation , kinetics , reaction rate , thermodynamics , inorganic chemistry , activation energy , organic chemistry , physics , quantum mechanics
A 17‐reaction mechanism model was postulated to describe the alkylation of isobutane with propylene using sulfuric acid as the catalyst. The scheme was based on the Schmerling carbonium ion mechanism with modifications introduced to account to iC 9 and iC 10 formation. Solving the steady state rate equations for the rate constants a set of 17 equations of the form k i = f ( rcj , rC k , …)/ g (C i , C k , …) were obtained. Experimental measurements were made in an ideally mixed, continuous‐flow stirred‐tank reactor, and the necessary data were obtained to compute the rate constants from 65°F to 135°F. The reaction model was found to be valid in the range of 81°F to 135°F using a 95% sulfuric acid catalyst since the rate constants obeyed the Arrhenius theory. The results obtained at 65°F and 95% sulfuric acid showed significant departure from the model. This was possibly due to a change in reaction mechanism. There was an apparent change in selectivity of the catalyst when the concentration was lowered to 90% sulfuric acid. This resulted in increased rates of formation of i C 9 's and i C 10 's and decreased rates of formation of i C 5 's, i C 6 's and i C 8 's.