Role of Pore Size on Thermalconversion and Catalytic Product Distribution by Alex Canney, Clay Wheeler & Brian Frederick

Our project within the FBRI focuses on producing sustainable fuels and chemicals using catalytic thermochemical conversion. One of the ways this can be done is by pyrolysis. The woody biomass is heated in the absence of oxygen, producing oxygenated aromatic compounds. The oxygen must be removed to make fuels or other specialty chemicals. Development of metal catalysts for hydrodeoxygenation is a relatively new area of research.

One process option is to burn the woody biomass in the presence of a limited amount of oxygen, producing primarily a combination of carbon monoxide and hydrogen. This combination is commonly referred to as syngas. The syngas can then be combined with more hydrogen and polymerized to produce alkanes in a process called Fisher-Tropsch synthesis. These alkanes of various lengths can then be distilled to produce quantities of the desired compounds ranging from ethane to wax.

One strategy to narrow the product distribution is to prepare the FeCo metal catalyst in a nanoporous material. The first step in understanding the effect of pore size in catalysis is to study the conversion of a series of alcohols on porous tungsten oxide materials that have already been synthesized. A microreactor system will be used to measure the conversion of alcohols into alkenes and ethers. The inlet and outlet gas compositions will be measured using gas chromatography-mass spectrometry (GC-MS). The reaction rates on porous WO3 and on non-porous WO3 will be measured for a series of small-to-large alcohol molecules, and the ratio of porous to non-porous rates will be calculated. The goal is to show that the ratio decreases as the size of the molecule increases, therefore demonstrating that the active sites in the pores are not accessible to the larger molecules.

Before carrying out the alcohol/WO3 reactivity experiments the GC/MS microreactor system needs to be set up and calibrated. Tasks include calibrating mass flow controllers, maintaining and tuning the GC-MS, qualifying the performance of the reactant delivery cells, and measuring the reactivity of the inert SiO2 reactor packing material.

REU Interview Notes 07/10/07

Alex Canney REU Interview Notes (pfd file)