George W. Roberts
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ProfessorB.S., Chemical Engineering, Cornell University (1961) Sc.D., Chemical Engineering, MIT (1965) Areas of interest: Email: groberts@eos.ncsu.edu |
Research |
Publications |
More than twenty years of my career has been spent in research and development with several industrial organizations. Consequently, my interests tend towards the applied side of the academic spectrum. The focus of our current research is on applying the principles of chemical reaction engineering to the solution of important problems in the areas of pollution prevention, pollution control, and alternate fuels.
One element of our program involves the synthesis, characterization, and testing of novel heterogeneous catalysts for producing higher alcohols from carbon monoxide and hydrogen in a slurry reactor. Higher alcohols such as ethanol, propanol, and butanol, as well as ethers derived from these alcohols, are used as additives in motor gasoline. The use of such "oxygenates" in gasoline is increasing rapidly in many parts of the world, driven by the clean-burning characteristics and the high octane ratings of these alcohols and ethers. More efficient and less costly routes for the production of higher alcohols are required. Our research has led to a deeper understanding of the effect of the composition of the slurry liquid on catalyst performance.
We are also using slurry reactors as a tool for carrying out bifunctional catalytic reactions. With this approach, reactive intermediates can be generated in-situ, opening up exciting new possibilities in environmentally benign chemical synthesis. Current research includes in-situ generation of formaldehyde as a step in the synthesis of methyl methacrylate and styrene.
Another area of interest is continuous polymerization in supercritical carbon dioxide. Many industrial polymerizations are conducted in organic solvents, resulting in the need to dispose of large quantities of organic waste. Even when a polymerization is conducted in an aqueous system, a liquid waste stream containing significant concentrations of the monomer and/or polymer is produced. Carrying out polymerizations in supercritical CO2 is an exciting new way to avoid producing such waste streams. The next challenge is to develop continuous processes for polymerizations in CO2. This will require a detailed conceptual and mathematical understanding of polymerization mechanisms and kinetics in supercritical CO2. The objective of this project is to study the continuous polymerization of vinyl fluoride, acrylic acid, and poly (bisphenol A carbonate) in the laboratory and to develop mathematical models that will describe the important process parameters, e.g., monomer conversion and molecular weight distribution, as a function of the operating conditions of the reactor.
Finally, we have carried out research on the hydrodynamics of gas-lift reactors, with emphasis on the effect of fast, gas-consuming reactions. We also are initiating a fundamental study of catalysts for the reaction of carbon dioxide and aliphatic acids such as acetic acid.
