Kinetic studies on the dimerization of isobutene with Ni/Al2O3as a catalyst for reactive distillation process

Isooctane is a promising gasoline additive that could be produced by dimerization of isobutene (IB) with subsequent hydrogenation. In this work, the dimerization of IB has been carried out in a batch reactor over a temperature range of 338–383K in the presence of laboratory prepared Ni/Al2O3as a catalyst and n-pentane as solvent. The influence of various parameters such as temperature, catalyst loading and initial concentration of IB was examined. A Langmuir–Hinshelwood kinetic model of IB dimerization was established and the parameters were estimated on the basis of the measured data. The feasibility of oligomerization of IB based on the reactive distillation was simulated in ASPEN PLUS using the kinetics developed. The simulation results showed that the catalyst of Ni/Al2O3had higher selectivity to diisobutene (DIB) and slightly lower conversion of IB than ion exchange resin in the absence of polar substances.