Health ‘ Science – New reactor means less waste, smaller size

Almost ten years of dedicated research have finally paid off for Pitt researcher Goetz… Almost ten years of dedicated research have finally paid off for Pitt researcher Goetz Veser.

Veser announced Tuesday his designs for a cleaner and safer — meaning less-explosive — micro-reactor at the American Chemical Society National Meeting in San Francisco.

The reactor controls the burning of hydrogen or methane gases to generate energy. Unlike reactors out there now, this one prevents the formation of pollutants, like nitrogen oxides.

Veser’s micro-reactor has tiny channels etched into silicon chips on the reactor’s walls. These channels absorb particles called “free radicals” which would normally speed up the reaction and increase the temperature inside the chamber. This can lead to explosions or form nitrogen oxide pollutants.

“Once adsorbed, the radicals will eventually desorb from the wall after recombination into much less reactive molecules. No waste is formed at all, unless you regard the greenhouse gas, carbon dioxide, as waste,” said Veser.

Veser is an assistant professor in the Department of Chemical and Petroleum Engineering. He started his research on catalytic reaction engineering in 1997 in Germany, and, with the support of the National Science Foundation’s CAREER Award, he eventually came to Pitt in 2002 to continue the research here.

The micro-reactor that he developed has many potential practical uses, most of which come from the scaled-down size. He defined micro-reactors as being ones that have at least one dimension in the micrometer range.

“The overall reactor could be as large as conventional reactors and some industrial companies are working on such concepts. The final reactor will probably, in most cases, be anywhere between the size of a laptop battery to the size of a trunk of a standard car,” he said.

“For some applications, such as hydrogen production for laptop fuel cells or a fuel-cell driven car, the compact size is a prerequisite to make it feasible at all,” he added.

Veser also noted that through this technology, conventional chemical processes could be improved, including the reduction of energy consumption, waste products and hazards in the reaction process.

Other scientists working in the field have taken the approach of trying to improve heat transfer methods. Veser’s reactor is different because it relies on the small size of the diameter of the channels in the reaction chamber. He explained that a reactor with a slightly larger diameter will not yield equally-good results.

“These effects are truly new and unique to the micro-domain,” he said.

Veser plans to further his research by continuing to look for ways in which he can selectively suppress undesired reaction chambers, thus steering the path of the chemical reactions.