Tech research looks for clean energy source |
Chemical engineer Junhang Dong and electrical engineer Hai Xiao have partnered with Arizona State University scientists to produce a system that monitors impurities during hydrogen production with nanotechnology, which uses very small particles. The U.S. Department of Energy is funding the work.
Xiao said while many scientists study nanotechnology, few put it to practical use as he and Dong are doing. Their technology could apply to hydrogen production from manufacture to distribution to use, Dong said.
Fuel cells operate on hydrogen, which people produce from natural gas or coal.
Dong said the hydrogen must be very pure, because too many contaminants can disable the fuel cell, causing power outages and damage.
"So it is critically important that you know everything about the fuel cell, about the hydrogen stream," Dong said.
Hydrogen's ability to explode also brings a need for careful observation. People cannot produce the gas without sensors to monitor composition of the hydrogen stream.
Hydrogen production takes place at temperatures greater than 932ºF.
"There is no such sensor that can be used at this temperature for a long period of time," Dong said.
Existing sensors can measure the chemical composition of the gas, but only at higher or lower temperatures.
Furthermore, the system's nanomaterial, a substance made of tiny particles, needs to conduct electricity as well as possible at the required temperature.
The sensor system also must provide real-time information, allowing operators to correct problems immediately.
The sensor consists of a communication optical fiber about the size of a human hair. A coating of two nanomaterial substances covers the fiber and interacts with chemicals in the gas stream.
The interaction changes the material's electrical and optical properties. A laser transmitted through the fiber interprets occurrences in the nanomaterial, and light reflects back to the system to indicate gas composition. Computer software shows operators the information.
The assistant professors developed the concepts in the past but are applying them to the current research done at Tech.
"In general, our work is for energy and environmental applications," Dong said.
Xiao said it also has homeland security uses. Some work has been done on testing for airborne explosives with the technology, Dong said.
In the current project, which began in July and is scheduled to end in June 2008, ASU scientists are identifying what materials interact with the gas of interest.Dong is developing the nanomaterial, while Xiao is working on a device to use the material in different applications, particularly the sensors.
Xiao said that during such research, they found scientists can use the sensor system to study the nanomaterial, as well as using the substance on sensors.