Morgantown, W.Va.— Researchers at the National Energy Technology Laboratory (NETL) received four patents in 2007 to improve the performance of combustion and fuel cell systems while capturing a variety of components from flue gas, including the greenhouse gas carbon dioxide (CO2).
“Each year, the corollary to the research efforts in the Department of Energy’s national laboratories is the award of patents that take us one step closer to achieving national goals for clean, secure, and affordable energy,” said NETL Director Carl Bauer. “This year, patents issued to NETL researchers will bolster the performance of the nation’s combustion and fuel cell systems, while improving the prospects for capturing CO2 and other gases.”
One of the NETL patents, a flow control device, was aimed at the fuel cell market but also has benefits for other applications, such as gas turbine combustion systems. The second patent, a sensor, can detect power-robbing conditions in gas turbines. A third patent involves the use of an aqueous ammonia-based scrubbing solution to capture polluting “acid gases” produced when coal is combusted. The final patent improves the CO2 capture capabilities and lowers the cost of solid sorbents.
Brief summaries of the four patents follow:
- Flow Control Device for Fuel Cells (patent number 7,159,841)—Along with their research partners at the University of Pittsburg, NETL inventors patented a flow control device to improve flow distributions within fuel cells. Although the effort was directed at fuel cells, the researchers discovered that the device can also be used to control flow in other applications, such as gas turbine combustion systems. In these combustion applications, the device could result in lower pollutant emissions, particularly nitrogen oxides (NOx). Through its University Research Initiative Program, NETL continues to develop sensor and control technologies for energy applications.
- Sensor for Gas Turbines (patent number 7,197,880)—NETL patented a sensor to detect a condition called incipient lean blowout, or LBO. The patented device detects LBO conditions before the gas turbine plant loses power and before these conditions cause significant hardware damage. The sensor would permit modern turbines, particularly those using the more susceptible dry, low-NOx combustion technology, to safely operate closer to the LBO limit, where emissions are lowest. NETL is now working toward commercializing the sensor.
- Multi-Component Removal in Flue Gas by Aqua Ammonia (patent number 7,255,842)—NETL researchers invented a wet-scrubbing technique to capture acid gases, including CO2, from flue gas at coal-burning power plants by using an ammonia-based solution to remove the gases. During the process, a salable fertilizer is processed and the spent ammonia solution is regenerated, while producing a stream of CO2, and recycled back to the scrubbing unit. The technique has been licensed to Powerspan Corp., New Durham, N.H., which plans to construct a 1-megawatt demonstration unit.
- Immobilized Amine Sorbents (patent number 7,288,136)—NETL inventors developed a method to reduce the cost of making solid sorbents that capture CO2 in large-scale gas-solid processes. The new method involves treating an amine to increase the number of secondary amine groups and impregnating the amine into a porous solid support. Using this treatment, the inventors have been able to increase the ability of the sorbent to capture CO2 and reduce the costs associated with using an amine-enriched solid sorbent.