Past and Present Research Systems of Green Chemistry

Biography

Biography: Katarina Fabicovicova

Abstract

Cellulose is the most abundant and non edible biopolymer of the world. Therefore, the utilization of this macromolecule and its integration in a bio-refinery concept is essential even in the near future of growing global shortage of crude oil. Herein we present results of the one-pot hydrogenolysis of cellulose to valuable chemicals, especially polyols, using supported bifunctional catalysts. The hydrogenolysis of cellulose under hydrothermal conditions in the presence of solid catalysts yields ethylene glycol and other valuable polyols such as propylene glycol, butanediol, and sorbitol. Besides our highly active nickel-tungsten catalysts [1], our ongoing research is focused on the development of stable catalyst systems and reaction engineering aspects of biomass conversion to chemicals. Optimization of reaction conditions, recycling tests for catalysts and different cellulose-pretreatment methods such as ball-milling gave a very promising catalyst, namely Ru-W on activated carbon (AC) [2]. Over the Ru-W/AC catalyst, which was ball-milled with cellulose for a very short time (4 minutes), the cellulose conversion of 100 % and overall polyols yield of 84 % within 3 hours reaction time could be achieved (493 K, hydrogen pressure of 65 bar, low catalyst/cellulose ratio (1/10)). The catalyst was also tested for its re-usability in a recycling test which showed a very good stability in six runs. Characterization of catalysts was undertaken for a better understanding of structure and performance of catalyst. Finally, first experiments showed that the optimized conditions can be successfully applied to the hydrogenolysis of real biomass. At very high conversion the product distribution depends on the individual biomass type. With application of a pretreatment method, we can influence the product distribution and increase the overall polyols yield by the hydrogenolysis of raw biomass.