(583e) Conversion of Acetone to Hydrocarbon on Titania Based Catalysts | AIChE

(583e) Conversion of Acetone to Hydrocarbon on Titania Based Catalysts


Daggolu, P. R. - Presenter, Washington State University
White, M. G. - Presenter, Mississippi State University

The conversion of biomass-derived syngas into a gasoline blend can be achieved by an alcohol route through the familiar TIGAS technology in which one of the intermediates is methanol. It is now known that when syngas is converted to intermediates that are higher alcohols (longer carbon chain than Methanol), dehydration of these species give higher yields of gasoline that what was observed when methanol is the intermediate. One catalyst that can convert syngas to higher alcohols is rhodium, but the rhodium catalysts also form ketones in significant yields among other oxygenates, apart from higher alcohols. Any commercially-viable technology involving this pathway must provide for the complete conversion of oxygenates to hydrocarbons. Hence, we studied the aldol condensation of acetone to mesitylene in high pressure conditions in hydrogen-rich atmospheres. These conditions were chosen as way to mimic the conditions inside commercial reactors during syngas conversion, where hydrogen is readily available.

Acetone is known to undergo self condensation to form mainly mesitylene with isophorone, xylenols and mesitylene oxide as main by-products on the same catalyst. Mesitylene is a hydrocarbon which can be left in the fuel stream, if modest yields of aromatics can be tolerated. Acetone is also known to form more varied aromatics on zeolites. Studies are performed on combining titanium with zeolites, such as HZSM-5, to form gasoline blends containing benzene, xylene, toluene and some aliphatic short chain hydrocarbons, from acetone. The yields obtained over physical mixtures of titania and HZSM-5, impregnated catalysts and separated beds will be compared. This combination will be optimized for direct conversion of acetone to gasoline range hydrocarbons.

Studies will be shown on these reactions at different conditions of pressure (0 - 1500 PSIg), temperature (175 ? 475oC) and flow rates( 0.1 -1.5 cm3/min) with pure, poly-crystalline titania catalyst. The best conditions for acetone conversion to mesitylene will be elucidated. Also, some insight shall be given into the mechanism of the reactions.