NETL research delivers efficiency for fossil fuel use

Lab gets patents for several technologies that make hydrocarbons cleaner

BY ALAN BAILEY FOR GREENING OF OIL 

The U.S. Department of Energy announced Feb. 17 that researchers in the agency’s National Energy Technology Laboratory, or NETL, have received patents for several new technologies, all targeted at the cleaner and more efficient use of fossil fuels.

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“The far-reaching innovations address a range of fossil-fuel issues, including hydrocarbon production; carbon dioxide capture and sequestration; emissions controls; and making fossil-fuel systems, such as boilers, turbines and fuel cells, more efficient,” DOE said.

Increased fuel efficiency

Several of the new technologies can lessen the environmental impacts of fuel usage in engines or burners by reducing fuel consumption and, as a result, reducing the volumes of exhaust produced.

For example, a new laser spark distribution and ignition system for reciprocating internal combustion engines and for fuel-burning turbines could bypass the need for traditional spark plugs and distributers, thus enabling engines to run lean, that is with less fuel in an engine’s air-fuel mixture, DOE said.

The resulting ultra-lean-burning engine operation would reduce the emission of various nitrogen oxide pollutants and allow engines to run at high efficiency, without incurring damage to engine components such as spark plugs—the high pressures necessary when running an engine in this way place great strain on conventional engine components, DOE said.

Eliminate combustion instability

NETL scientists have also invented an internal monitoring system for gas turbine engines, to eliminate combustion instability when running these engines so lean that the fuel content in the fuel-air mixture comes close to the lower limit for sustained combustion. Using the new technology, a sensor in the form of an electrode integrated into the engine compartment where the fuel is burned passes information to the engine’s control system, triggering adjustments to the fuel-air mixture to continuously ensure that fuel combustion remains stable.

Another new sensor system monitors the air-flow direction and speed in hybrid fuel cell-and-turbine electrical power generation systems. In these hybrid systems, the exhaust gases from fuel cells drive a turbine-powered electric generator, with both the fuel cell and the generator outputting electricity—the new sensor system would further enhance the already high efficiency of these systems, as well as improving system safety.

“Since fuel cell-turbine hybrid systems are expected to dramatically increase power generation efficiency from fossil fuels while reducing emissions, this new type of sensor promises to boost efforts towards clean, abundant energy at affordable cost,” DOE said.

More efficient steam generation

And as an efficiency improvement for fossil-fuel fired boilers, used for generating steam for power generation and other industrial applications, NETL’s newly invented oxy-fuel combustion system uses oxygen rather than air for the fuel combustion process. The resulting reduced flow rate of gases entering the boiler’s burner system enables boiler plants to be reduced in size, while also reducing the volume of exhaust gases.

“Since NETL’s oxy-fuel boiler system is designed to capture and sequester carbon dioxide, this system results in a near zero emissions plant,” DOE said.

Capturing emissions from fossil fuels

Some of the newly patented technologies target the capture and storage of emissions from fossil fuel use.

For example, new NETL-designed carbon dioxide sorbents can be regenerated for re-use and reduce the cost of scrubbing carbon dioxide from power plant emissions, DOE said. The sorbents remove carbon dioxide from the fuel gases entering a power unit such as a turbine, thus reducing the amount of carbon dioxide in the unit’s exhaust.

“NETL’s novel sorbents are not only inexpensive but also possess higher carbon dioxide absorption capacities than existing sorbents, and can be reused for additional cycles,” DOE said.

Synthetic

And, for the disposal of captured carbon dioxide, NETL has invented a process that causes carbon dioxide to react with magnesium-rich minerals in a manner similar to the natural weathering of rocks, to produce stable, solid, carbon-holding minerals, ready for long-term storage. The new process greatly speeds up the “weathering” reactions, thus enabling the practical use of the reactions in carbon sequestration, DOE said.

Other NETL inventions include a new technique for capturing mercury released from coal-fired power plants; a new protective coating that reduces the oxidation of components in turbines and fuel cells; and a new technique for determining the optimum particle size for the catalysts used in synthetic gas-to-liquids processes.

Link of interest

Press release on NETL patents

Contact Alan Bailey via Kay Cashman at publisher@greeningofoil.com