Titanium- and aluminum-catalyzed ethylene dimerization to 1-butene (AlphaButol process) has been practiced industrially for decades, yet inevitable reactor fouling with polyethylene byproduct remains a fundamental challenge. Spectroscopic data has shown that a complex mixture of Ti(III) and Ti(IV) species are formed, depending on the Al/Ti ratio and presence of ligands such as tetrahydrofuran. This concomitant mixture of species has frustrated mechanistic analysis and rational prevention of reactor fouling. Herein, we utilize computational molecular modelling (extended tight binding theory and density functional theory as implemented in XTBDFT) to examine the mechanism of 1-butene and polyethylene formation with computational molecular modelling, and we develop novel anti-fouling agents that effectively reduce polyethylene formation while retaining 1-butene productivity. This technology has been patented and licensed across the industry.
- Industrial vs. academic research priorities
- Application of molecular modeling to improving catalysis
- Importance of conformational searching for mechanistic molecular modelling