Kontinuierliche Isobutan/2‐Buten‐Alkylierung in einem Tropfensäulenreaktor mit ionischen Flüssigkeiten als Katalysatoren

Effective and Intrinsic Kinetics of Liquid-Phase Isobutane/2-Butene Alkylation Catalyzed by Chloroaluminate Ionic Liquids

“…A similar result can be obtained from the k chem values reported by Aschauer and Jess, , who measured the effective kinetics in a static IL/isoalkane/alkene system at a temperature of 25 °C. We next calculate the intrinsic rate constant, k chem , at a temperature of 5 °C from the respective value of Aschauer and Jess at 25 °C.…”

“…The reaction rates in the organic and IL phases (eqs and ) are related to each other by the ratio of the volumes of the two phases r normalo , org = r normalo , IL V IL V org The concentrations at the phase boundary in the organic phase ( c o,org * ) and in the IL ( c o,IL * ) are linked by the Nernst partition coefficient, K c,o , based on molar concentrations (mol m –3 ) c normalo , IL * = K normalc , normalo c normalo , org * K c,o is easily derived from the mass-related partition coefficient K w,o K normalc , normalo = K normalw , normalo ρ IL ρ org For 2-butene, K w,o at 5 °C was extrapolated from solubility data of longer-chain analogues of isoparaffins and 2-olefins in a neutral ionic liquid at 25 °C reported by Aschauer and Jess. , According to Aschauer and Jess, , the temperature dependency of K w,o can be neglected. The obtained K c,o value of 0.15 was multiplied by a factor of 2.5 to account for the increase in hydrocarbon solubility when passing from the neutral ( x AlCl 3 = 0.5) to the Lewis-acidic ( x AlCl 3 = 0.64) regime of the ionic liquid. , The combination of eqs , , and yields − normald c normalo , org normald t…”

“…Experiments with a static reaction system consisting of chloroaluminate IL and C 5 or C 6 isoparaffins and olefins revealed that the thickness of the IL layer in which the alkylation reaction takes place is only a few micrometers. 20,21 For C 4 alkylation, an even smaller IL film thickness is expected, because the reactivity of protonated olefins derived from alkylation initiation reaction decreases in the order C 4 > C 5 > C 6 . Thus, the effective reaction volume in hydrocarbon-continuous dispersions is the spherical shell volumes of the ionic liquid droplets.…”

“…For 2-butene, K w,o at 5 °C was extrapolated from solubility data of longer-chain analogues of isoparaffins and 2-olefins in a neutral ionic liquid at 25 °C reported by Aschauer and Jess. 20,21 According to Aschauer and Jess, 20,21 the temperature dependency of K w,o can be neglected. The obtained K c,o value of 0.15 was multiplied by a factor of 2.5 to account for the increase in hydrocarbon solubility when passing from the neutral (x AlCl 3 = 0.5) to the Lewis-acidic (x AlCl 3 = 0.64) regime of the ionic liquid.…”

“…The obtained K c,o value of 0.15 was multiplied by a factor of 2.5 to account for the increase in hydrocarbon solubility when passing from the neutral (x AlCl 3 = 0.5) to the Lewis-acidic (x AlCl 3 = 0.64) regime of the ionic liquid. 20,21 The combination of eqs 7, 12, and 13 yields…”