Oligomerization of 1-decene over sulfated alumina catalysts for the production of synthetic fuels and lubricants: modelling and verification

Abstract

The three-factor Box-Behnken design and the response surface methodology (RSM) were used to optimize the production of C20 (transportation fuel) and C30 + (lubricant oil) hydrocarbons obtained from 15 different oligomerization reactions of 1-decene over sulfated alumina catalysts in batch operation mode. The physiochemical properties of the sulfated alumina catalysts were characterized by N2 sorption, XRD and NH3-TPD. The formulated quadratic models as a function of three independent variables of reaction temperature (448–473 K), sulfuric acid concentration (2.5–4.5 M) and catalyst amount (5–15 wt%) were verified by the experimental results (1-decene conversion and product composition) with a coefficient of determination higher than 0.97 for all dependent variables (conversion, amount of C20 and C30 +). The optimal amount of C20 (65.4 wt%) was achieved at 473 K, using 3.5 M sulfated alumina and 8.8 wt% of catalyst. Similarly, the optimization of C30 + (47.7 wt%) was revealed at 473 K, using 3.5 M sulfated alumina and 15 wt% of catalyst. It was concluded that oligomerization over sulfated alumina was successfully optimized using Box-Behnken design.