Industrial & Engineering Chemistry Research, Vol.46, No.2, 400-410, 2007
Linear alpha-olefins from linear internal olefins by a boron-based continuous double-bond isomerization process
Linear alpha-olefins (LAOs) find industrial use as high-value chemical intermediates. Most of the LAO production is based on ethylene oligomerization and does not yield a market-related product distribution. Various non-ethylene-based LAO production routes have been evaluated and it was found that a process based on boron chemistry was the most likely to be successfully commercialized. Process flow diagrams for a low-temperature (150-200 degrees C) continuous boron-based process to produce LAOs from linear internal olefins are presented, showing that it can be designed with or without a solvent in the boron cycle. Experimental data are presented to illustrate progress made in understanding the chemistry associated with such a process. It is shown that (a) solvent exchange competes with hydroboration and is rate-controlling by regulating borane availability, (b) reactivity of substituted boranes is determined by the availability of the empty p(z) orbital of boron, (c) steric effects influence the rate of hydroboration and isomerization, (d) alkylborane isomer distribution is temperature-dependent and back-isomerization of terminally bonded alkylboranes is possible, and (e) thermal dehydroboration is more efficient than olefin liberation by displacement.