Pitt professor designs less-risky reactor for clean, safe energy

Reactors that burn hydrogen or natural gas to generate energy can be dirty and dangerous. The mix of air with hydrogen or natural gas can explode easily if composition and temperature are not carefully controlled. And reactors often produce polluting byproducts.

Now, University of Pittsburgh chemical engineering professor Goetz Veser has created a safer alternative--microreactors that won't explode, no matter what the gas composition or how hot they get, and that can keep undesirable pollutants, like nitrogen oxides (NO_x), from forming. His results could be used to design processes for safe, clean energy production and hydrogen storage. Veser will discuss his findings today during a presentation at the 232nd American Chemical Society National Meeting in San Francisco, Calif.

Reactor explosions can happen either when the reaction gets too hot or when atoms called "free radicals" break away and start to split the bonds of other molecules. In both cases, the reaction speeds up and the temperature increases until--kaboom!

But Veser's microreactors are actually "inherently safe," he says. "Even if the temperature goes completely through the roof, based on the kinetics of the system, explosions cannot happen."

Veser, who also is a researcher in Pitt's Gertrude E. and John M. Petersen Institute of NanoScience and Engineering, created the reactors by etching tiny channels into silicon chips, using a platinum wire catalyst and running a mix of hydrogen and air through the channel. "It's one of the toughest systems you can imagine," he says. "If anything would blow up, this would." (Think Hindenburg.)

But nothing happened--other than the controlled burning of hydrogen. The walls did indeed adsorb any pesky radicals floating around, keeping the reaction running smoothly.

Veser has since extended the technology to burning methane; he has found that not only can the walls stave off explosions, they also can steer the course of the reaction. For example, some NO_x is formed by the heat and some by radicals. Veser found that at a particular size, the microreactor walls adsorb the radicals that cause NO_x, while letting the reaction go ahead. "This is a completely different way of approaching a clean combustion technology," he says.

Source: University of Pittsburgh

Related stories:

Study details how diabetes drives atherosclerosis
Researchers have discovered how diabetes, by driving inflammation and slowing blood flow, dramatically accelerates atherosclerosis, according to research to be published in the March 14 edition of the journal Circulation Research.
Separating the brain's 'bad' from 'good' iron
Duke University chemists are developing ways to bind up iron in the brain to combat the neurological devastation of Parkinson's and Alzheimer's diseases. The key is to weed out potentially destructive forms of iron that generate harmful free radicals while leaving benign forms of iron alone to carry out vital functions in the body.
You still can't drink the water, but now you can touch it
Engineers have developed a system that uses a simple water purification technique that can eliminate 100 percent of the microbes in New Orleans water samples left from Hurricane Katrina. The technique makes use of specialized resins, copper and hydrogen peroxide to purify tainted water.
Scientists Convert Modern Enzyme into its Hypothesized Ancestor
By making a single substitution in the amino acid sequence of a modern enzyme, scientists have changed its function into that of a theoretical distant ancestor, providing the first experimental evidence for the common origin of the two distinct enzyme types. The research, conducted by a team that includes scientists from the U.S. Department of Energy's Brookhaven National Laboratory and the Karolinska Institute in Stockholm, Sweden, will be published online the week of October 30, 2006, by the Proceedings of the National Academy of Sciences.
Scientists discover new method for creating high-yield single-walled carbon nanotubes
Cousins of the 1996 Nobel Prize-winning buckyball, carbon nanotubes have taken the nanotechnology industry by storm. Exhibiting extraordinary strength, flexibility and unique electrical, mechanical and optical properties, these hollow microscopic fibers are being integrated into numerous electronic and biological products—high-performance computer chips, combat jackets, bomb detectors and drug delivery devices for the treatment of diseases.
The Living Worlds Hypothesis
Saturn's moon Titan is enveloped in a thick orange haze, and the organic particles that make up that smog have been raining out of the atmosphere and down onto the surface for millennia. This rich chemical brew is thought to be ripe for life's origin, similar in some aspects to Earth in its earliest days.
Can genetic information be controlled by light?
Researchers at Kiel University have succeeded in showing that DNA strands differ in their light sensitivity depending on their base sequences. Their results are reported by Nina Schwalb and colleagues in the current issue of the journal Science appearing on Oct. 10, 2008.
Mouse studies suggest daily dose of ginkgo may prevent brain cell damage after a stroke
Working with genetically engineered mice, researchers at Johns Hopkins have shown that daily doses of a standardized extract from the leaves of the ginkgo tree can prevent or reduce brain damage after an induced stroke.

News discussion:

General Science news