(127c) Selective Oxygen Removal to Intermediate Oxygenates By Brute Force

Any process with the goal of producing alternative fuels must meet two criteria in order to be considered technically and economically feasible.  First, the process must demonstrate selectivity to transportation fuels which are valued at a premium over other fuel hydrocarbons or the feedstock.  Second, the process must demonstrate high yields to reduce capital costs.  These two criteria have led to the adaptation of existing refining processes for the production of alternative transportation fuels where brute force (high temperatures, and often high pressure and/or  hydrogen) are used.  The complication is in situations where an intermediate in the reaction pathway is the most valuable product and the thermodynamic product is undesirable.  This work focuses on high productivity and high selectivity reaction pathways for the production of aliphatic alcohols from glycols.  The reaction path was chosen to avoid the traditional hydrotreating pathways that would lead to light paraffin formation.  Instead the reaction pathway includes a combination of thermodynamic and kinetic limitations which dramatically increased the selectivity for single oxygen atom removal.    In the case of propylene glycol, the use of a bifunctional catalyst composed of a weak transition metal and a solid acid resulted in a doubling of the n-propanol yield at high gas hourly space velocities and high conversions.  Dehydration becomes the primary mechanism for oxygen removal, while weak hydrogenation activity prevents the formation of secondary cyclic ether products by promoting desorption of monoxygenated products.