The Lawrence Berkeley National Laboratory (LBL) has developed near-zero-emission gas turbines using pure hydrogen as a fuel. But because this LSI (low-swirl injector) technology also can use other fuels, it has the potential to help eliminate millions of tons of carbon dioxide and thousands of tons of nitrous oxides (NOx) from power plants each year. In fact, burners with the LSI emit 2 parts per million of NOx, more than five times less than conventional burners. The multi-patented technology is currently available for licensing. I sure hope that a utility company will be interested.
On the left, you can see photographs of a high-swirl injector (HIS) (top) and of a low-swirl injector (LSI) (bottom) (Credit: LBL). These pictures have been extracted from an article called "A comparison of the flowfields and emissions of high-swirl injectors and low-swirl injectors for lean premixed gas turbines" which was published in 2004 in the Proceedings of the Combustion Institute (PDF format, 9 pages).
The LSI technology has been developed in LBL's Environmental Energy Technologies Division by Robert Cheng and David Littlejohn with some help from Solar Turbines Inc., a Caterpillar company.
Now, let's look at the LBL news release to discover the LSI technology. "'This is a kind of rocket science,' says Cheng, who notes that these turbines, which are being used to produce electricity by burning gaseous fuels, are similar in operating principle to turbines that propel jet airplanes."
But how the LSI technology works? "The low swirl injector is a mechanically simple device with no moving parts that imparts a mild spin to the gaseous fuel and air mixture that causes the mixture to spread out. The flame is stabilized within the spreading flow just beyond the exit of the burner. Not only is the flame stable, but it also burns at a lower temperature than that of conventional burners. The production of nitrogen oxides is highly temperature-dependent, and the lower temperature of the flame reduces emissions of nitrogen oxides to very low level."
Besides emitting much lower levels of NOx than conventional turbines, "a more significant benefit of the LSI technology is its ability to burn a variety of different fuels from natural gas to hydrogen and the relative ease to incorporate it into current gas turbine design — extensive redesign of the turbine is not needed. The LSI is being designed as a drop-in component for gas-burning turbine power plants."
It's interesting to note that the LSI technology recently won a R&D 100 Award from R&D Magazine as one of the top 100 new technologies of the year. In fact, LBL won three of these awards (LBL news release, July 5, 2007).
Now, if you run a utility company, here is how you can license this ultraclean low swirl combustion technology.
But if you need more information before opening your checkbook, here are three documents to read.
Sources: Lawrence Berkeley National Laboratory news release, August 1, 2007; and various websites
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