Catherine Brewer - Dedicated to Teaching and Learning

Academic alchemist Catherine Brewer is blending study disciplines to create her own unique niche. The Washington State native now in her second year as a doctoral student at Iowa State, has morphed an interest in English to chemistry into her current passion, chemical engineering.

As an undergraduate, Brewer developed an interest in green chemistry, using biocatalysts-enzymes, rather than metal catalysts to promote chemical reactions.

"An enzyme does the same thing as a catalyst at ridiculously low temperatures," explains Brewer, "with a high amount of selectivity and without creating as many harmful wastes." The challenge, though, is how to get the biological processes to produce the higher product concentrations desired for industrial use.

For her doctoral research, Brewer chose to study mechanisms of fast pyrolysis, a process used in feedstock conversion to biofuels, with Robert Brown, Bioeconomy Institute director, Hoover Chair and professor of Mechanical Engineering.

But while attending the 2007 "Growing the Bioeconomy Conference," Brewer's focus shifted following Cornell University Professor Johannes Lehmann's presentation about biochar and its fertility-conferring effects observed in anthropological sites in the Amazon jungle.

"In all thermochemical processes we make biochar," says Brewer. "And charcoal is one of the most stable forms of organic carbon in soil."

Her interest was kindled with disposing of a "waste" product, sequestering carbon and improving soil health in one swath. Now exclusively focused on biochar, Brewer is collaborating with soil scientists in the Departments of Agronomy and Horticulture, comparing the soil response to chars made from a variety of feedstocks including switchgrass and corn stover.

Brewer is currently analyzing physical and chemical properties of biochar samples for mineral content, surface area, carbon structure composition and presence of functional groups to determine which type of char is best suited to particular soil types and how to make that kind of char.

The same char will not be suitable for all soil types Brewer points out. "It will depend on what one is trying to grow, the type of tillage, and how these factors come together."

PSI Fellowships are a valuable recruiting tool, attracting top doctoral candidates. After one year as a PSI Fellow, Catherine Brewer was awarded a prestigious National Science Foundation Graduate Research Fellowship.