Ethanol is being widely used as a gasoline additive. But it is well known that higher alcohols have higher heat value than ethanol. Hence we studied the possibility of upgrading ethanol to higher alcohols, in particular, to 1- butanol. This was studied using titanium dioxide (Titania), zirconium dioxide (Zirconia) and modified zirconia catalysts. Initial batch reactor runs have established the proof of concept for this novel technology. Then we ran these experiments in flow reactor to optimize the conditions. We studied the influence of temperature, pressure, ethanol flow rate and modifications of catalyst on the yields of 1-butanol from ethanol. The results showed that high pressures and temperatures result in higher yields of 1-butanol. Also it was shown that on zirconia; ethanol can be converted to not only 1-butanol put to even higher alcohols of up to 1-nonanol.
The mechanism of the reaction was also studied using molecular simulation software SPARTAN (Wave function Inc.). Hartree-Fock method was employed to calculate total energy of molecular the system for various possible intermediates. We have considered 3 main pathways, Guerbet chemistry, Ethanol reaction with ethylene and Ethanol self condensation. The simulation was performed on both titania catalyst and zirconia catalyst. These results will be presented in detail.
Presently, Some modified zirconia catalysts are being studied for converting ethanol to higher alcohols. Particularly promoters are being tested. Results are expected in a few weeks.