Opportunities for Renewable Fuels using Molecular Sieve Basic Catalysts
George Huber (Chemical Engineering) and Scott Auerbach (Chemistry)

Global climate change from atmospheric carbon forces the development of renewable sources of energy that are “net carbon neutral.” Cellulosic biomass provides an extremely attractive feedstock because plant growth soaks up as much carbon as is emitted during biofuel combustion. However, unlike the process of converting corn starch to ethanol, converting cellulosic biomass to ethanol and other fuels remains a challenging (i.e. expensive) process even with today's best available technologies. Modern petrochemical refineries have solved this problem for fossil fuels through the discovery of heterogeneous catalysts tailored for production of a portfolio of fuels and chemicals. So it will be with the biorefinery of the future. New heterogeneous catalysts need to be developed that convert the components of cellulosic biomass into ethanol, other alcohols, gasoline, diesel, olefins, and other high-value chemicals. Most of the components of cellulosic biomass are oxygenated molecules, requiring the development of catalysts with basic (not acidic) active sites.

In this project, students will study and develop functionalized zeolite catalysts, which contain nanopores that help steer reactions toward desired products. The zeolites under study are amine-substituted molecular sieves, which show great promise as “shape-selective” basic catalysts (Astala, R. and S.M. Auerbach, J. Am. Chem. Soc.2004, 126, 1843). We will also compare the activities of these novel zeolite catalysts with conventional solid base materials for condensation, esterification, and transesterification reactions (Huber, G.W., et al., Science, 2005. 300, 2075).

Investigation of catalysis: An REU student in Huber’s group will study catalysis of condensations, esterifications, and transesterifications as models for the production of diesel fuels and diesel fuel additives from cellulosic biomass and triglycerides. The activity of nitrogen-substituted zeolites will be compared with conventional basic catalysts.

Theoretical analysis and modeling: An REU student working in Auerbach’s group will perform quantum chemical calculations using user-friendly software packages such as Gaussian03, to predict which zeolites may offer the strongest base sites.

Collaborative effort: The REU students will work together to apply the structure-property relationships developed in the complementary studies above to fine tune the catalyst for optimal performance.

BACK TO INTERNSHIP RESEARCH PROJECTS