Liquid-Phase Isobutane Alkylation with Butenes over Aluminum Chloride Complexes Synthesized In Situ from Activated Aluminum and tert-Butyl Chloride
Kinetics and Catalysis
, E-ISSN: 1608-3210
Institute of Hydrocarbons Processing, Siberian Branch, Russian Academy of Sciences, Omsk, 644040 Russia
Omsk Scientific Center, Siberian Branch, Russian Academy of Sciences, Omsk, 644040 Russia
The liquidphase interaction between isobutane and butenes at 303 K and 2.5–3.0 MPa has been inves
tigated using activated aluminum (Al*)–tertbutyl chloride (TBC) model system (TBC : Al* = 0.35–4 mol/mol).
It has been demonstrated by attenuated total reflection FT–IR (ATR–FT–IR) spectroscopy that the cata
lytically active aluminum chloride complexes forming in situ in the hydrocarbon medium vary in composi
tion. Alkylation as such takes place at equimolar proportions of the reactants (TBC : Al* = 1 : 1) and butenes
feed mass flow rate of 5 h–1 per gram of Al*. According to ATR–FT–IR data, the most abundant aluminum
complexes resulting under these conditions are the and ions and, probably, the molecular
complex AlCl3 ⋅ secC4H9Cl. In a fourfold excess of TBC over Al* at butenes mass feed rate of 2.5 h–1, isob
utane undergoes selfalkylation. In this case, the ion is not detected and the most abundant com
plexes are , and the molecular species AlCl3 ⋅ tertC4H9Cl. It is hypothesized that the
ion plays the key role in the liquidphase alkylation of isobutane with butenes.