Using polyfurfuryl alcohol to improve the hydrothermal stability of mesoporous oxides for reactions in the aqueous phase

Authors: CHUNG, SAMUEL - Villanova University; LIU, QIULI - University Of South Carolina; JOSHI, UPENDRA - University Of South Carolina; REGALBUTO, JOHN - University Of South Carolina; Boateng, Akwasi; SMITH, MICHAEL - Villanova University; COE, CHARLES - Villanova University

Submitted to: Journal of Porous Materials Select Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2017
Publication Date: 6/4/2017
Citation: Chung, S., Liu, Q., Joshi, U.A., Regalbuto, J.R., Boateng, A.A., Smith, M.A., Coe, C.G. 2017. Using polyfurfuryl alcohol to improve the hydrothermal stability of mesoporous oxides for reactions in the aqueous phase. Journal of Porous Materials Select Science. doi: 10.1007/s10934-017-0451-9.

Interpretive Summary: Pyrolysis oil is a liquid biofuel intermediate obtained by heating woody biomass without burning it, in a process called pyrolysis. Pyrolysis oil contains high levels of oxygen and to be compatible with petroleum, needs to be upgraded by replacing the oxygen with hydrogen. This is done with an additional process called hydrodeoxygenation (HDO) using solid catalysts at high pressure and temperature. Since pyrolysis oil typically contains up to 30 vol% water, the solid HDO catalysts must also be stable in the presence water at these rigorous conditions. We investigated the effect of protective carbon coatings on a variety of common catalyst materials including silica, mixed zirconia-silica oxides and alumina. Polyfurfural alcohol was found to be the best carbon source for the protective coating; it was able to substantially preserve the catalyst properties in water at temperatures as high as 200 degrees C and pressures as high as 400 pounds per square inch. This new information will be valuable for researchers and industries who are searching for economical catalysts to upgrade bio-oil and other materials into sellable products.

Technical Abstract: Hydrodeoxygenation (HDO) of bio-oils derived from the pyrolysis of woody biomass is required to improve the stability and heating value of the liquid hydrocarbon products. Since pyrolysis produces bio-oils having up to 30 vol% water, HDO catalysts must not only be active and selective, but also stable under hydrothermal conditions associated with HDO upgrading in the liquid phase. We investigated the effect of carbon coatings on a variety of silica, mixed zirconia-silica oxides and alumina. Surface area and porosity changes from exposure to controlled steaming conditions were used to evaluate the effectiveness of carbon coating on support stability. Systematic studies of the effects of the composition and structure of the carbon precursor, the inclusion of a zirconium modifier, the carbon loading and carbonization conditions led to the development of highly stable carbon modified zirconium silicate and mesoporous alumina supports that substantially maintain pore size distribution and surface area after steaming at 493K with 400 psi of steam pressure.