Kinetics study on alkylation of isobutane with deuterated 2-butene in composite ionic liquids

Abstract

The deuterated 2-butene was used to determine the alkylation reaction of isobutane and 2-butene in the composite ionic liquid ([BMIM]Cl-AlCl3-CuCl, CIL). The alkylation reaction was investigated in a batch stirred reactor. The self-alkylation and the oligomerization of 2-butene are more likely to occur in the CIL. The key components of the alkylates, such as trimethylpentane (TMP), dimethylhexane (DMH), light ends (LE), and heavy ends (HE), were investigated at different reaction temperatures. The kinetics model with the primary and secondary reactions was established to predict the alkylation reaction. In order to test the reliability of the kinetics model, the solubility and diffusivity of isobutane in the CIL were measured. The isobutane alkylation under the industrial reaction conditions was also studied in a static mixer. Whether in the traditional batch reactor or the static mixer, the predicted data from the kinetics model are in good agreement with the experimental values. The obtained model is much more reliable to describe the alkylation reaction catalyzed by ionic liquids. By using deuterated 2-butene and on-line rapid analysis technology, the relationship between the isobutane-to-olefins ratio and the kinetic parameters was determined.