Catalytic Conversion of Bioethanol to 1,3-Butadiene

Determining the fundamental details of the catalytic conversion of bioethanol to butadiene, a poorly understood reaction at present, is needed in order to guide the rational design of advanced green catalysts for the bioethanol conversion to butadiene for the manufacture of green tires. Silica-supported ZrO₂ and ZnO catalysts were synthesized to study the mechanism and kinetics behind the conversion of bioethanol to 1,3-butadiene. The ZrO₂ catalysts were synthesized by incipient wetness impregnation from toluene solutions of zirconium (IV) n-propoxide onto a SiO₂ support. The ZnO catalysts were prepared by incipient wetness impregnation from aqueous solutions of zinc acetate dihydrate onto a SiO₂ support. The catalysts were dried overnight and calcined in air at 500^oC. The catalytic activity of each catalyst was tested in a fixed-bed reactor and the products were analyzed by gas chromatography (GC) with a flame ionization detector (FID). Several experiments were conducted to study the kinetics which include time to achieve steady state, and temperature/pressure effect on ethanol conversion. The surface kinetics of the ethanol conversion pathways to 1,3-butadiene were also investigated with Temperature Programmed Surface Reaction (TPSR) spectroscopy.

The findings will be presented and discussed.