ON THE ABSORPTION OF ISOBUTENE AND TRANS-2-BUTENE IN SULFURIC-ACID-SOLUTIONS

In reactions in which alkenes react in the presence of homogeneous Bro nstedt acid catalysts, the protonation step is rate determining. Exist ing reaction rate correlations for protonation of butenes in sulfuric acid solutions are not consistent and limited to sulfuric acid concent rations below 80 wt %. The absorption of isobutene and trans-2-butene in sulfuric acid solutions was studied in the range of 38-98 wt %. Ree valuation of Literature data, completed with new data from this study, revealed a set of kinetic rate data which coincide satisfactorily. Ex periments: and modeling of the absorption experiments showed a strong dependence of the reaction rate on local mixture composition through t he activity coefficient of the protonating agent. This strong dependen ce prevents the occurrence of a diffusion-limited absorption regime. A pplication of the usually used criteria for operating in the kinetic r egime can lead to erroneous results.