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Sacramento Heating and Cooling Plant

Sacramento Power Plant Showcases New, Advanced Ultra Low NOx Burner 

Natural Gas-fired Boiler for 23 California Government Buildings Reduces Emissions 70 Percent in Demonstration Project
 

CHICAGO " Dec. 8, 1999 " Early in 1998, the State of California faced a thorny problem with its General Services Heating and Cooling Plant in Sacramento.

The plant, which heats and cools 23 government buildings, was experiencing difficulty achieving full capacity using a set of new, low-emission burners installed to meet 30 parts per million (ppm) of nitrogen oxide (NOx) emissions, a major contributor to ozone pollution and photochemical smog. Among the plants customers is the State Capitol Building, where senators and assemblymen have enacted some of the nations strictest air-quality legislation. 

Today, the Sacramento plant is a showcase for the first installation of one of the most advanced emissions-performance technologies on the market, the Ultra Low NOx Watertube Boiler Burner. With the installation, the plant has achieved full compliance and is no longer challenged to meet its operating permit. NOx emissions from one of the facilities two natural gas-fired boilers have been reduced more than 70 percent, from more than 30 ppm to less than 9 ppm. 

In addition to achieving extremely low NOx emissions, the plant is able to operate the boiler at maximum efficiency, saving more than $75,000 annually in fuel costs. These savings do not include the avoided costs of other, more costly NOx reduction options. For example, use of standard low NOx burners and selective catalytic reduction (SCR) to achieve ultra low NOx emissions requires about $6,000 of capital costs and $1,300 for operating costs per ton of NOx removed. Corresponding costs for the Ultra Low NOx burner are $2,800 and $0, respectively. In the Sacramento application, the Ultra Low NOx installation is equivalent to about one-half of the capital costs, or two years of operating costs, for the low NOx burners and SCR.

“We can comfortably guarantee emissions below 9 parts per million with 400 degrees Fahrenheit pre-heated air, which ensures maximum boiler efficiency. That’s a major accomplishment," said Steve Londerville, vice president of R&D and chief engineer at Coen Company Inc., which manufactures the burner.  

“What is most significant about the technology is its ability to achieve ultra low NOx emissions using pre-heated air," said Robert Gemmer, project manager at Chicago-based GRI, which helped develop the burner. “This is extremely difficult to do. Previously, you had to sacrifice emissions if you wanted to achieve high efficiency. Conversely, complying with emissions regulations meant relinquishing efficiency. The answer for some operators has been exhaust gas cleanup, which is similar to catalytic converters on automobiles. However, they are expensive to buy and costly to operate. Consequently, they have not been well received by end users. With the Ultra Low NOx burner, you can in effect have your cake and eat it, too."

The Ultra Low NOx burner uses a proprietary process in which the staged mixing of air, fuel and flue gas recirculation minimizes formation of NOx in the flame. Development of the burner began in October 1994, when Coen was selected to develop a boiler burner capable of emitting single-digit NOx. GRI, the natural gas industry’s research, development and commercialization organization, led the $3.3 million program, which included funding from the Southern California Gas Company, Los Angeles, and the California Air Resources Board (CARB). Also participating were the University of California at Irvine, and Arcadis Geraghty & Miller, Mountain View, Calif. 

While current emissions regulations do not require ultra low NOx emissions, the GRI partnership foresees an emerging market for such burner applications. 

“We anticipate that several market drivers will begin motivating end users to adopt advanced technologies that allow them to exceed emissions limits," said Gemmer. “These drivers include the merits of over-controlling one major source to avoid installation of new equipment throughout a facility, trading emissions credits in areas with cap-and-trade procedures in place, and as a hedging strategy against future, more stringent regulations.

“We also envision that ultra low NOx technologies will begin to capture the attention of plant operators, especially those operating in regions with marginal air quality," Gemmer said. “These burners offer two powerful incentives: solid economics and flexibility. The burner can be installed at a fraction of the cost of the lowest priced post-treatment systems. In addition, plant operators are finding they can significantly reduce capital investments and still achieve full compliance by converting a few burners with the ultra low NOx option instead of converting multiple burners to conventional low-NOx burners. The strategy is simple. If you over-comply on one unit, you can avoid the high costs of making capital investments on another.

In the meantime, the GRI partnership is working on the next generation of ultra low NOx burners. An Optical Flame Management Scanner is being developed that will allow Coen's Ultra Low NOx burner to achieve its ultimate NOx emissions-reduction capability. Coen expects the scanner will be market ready in about 18 months. 

GRI manages a research, development and commercialization program that benefits the entire natural gas industry and its customers, as well as targeted RD&C efforts in partnership with individual organizations and consortia. GRI technologies improve the competitiveness of natural gas and provide cost savings and other benefits for customers.  

Coen specializes in the design, manufacture, servicing, and maintenance of burner equipment and combustion systems. With over 10,000 installations worldwide, Coen burner equipment and combustion systems provide optimum performance, meeting the needs of the industrial boiler, utility boiler, cogeneration, wood products, pyro-processing, solid fuel, refinery, oil recovery/steam flood and petrochemical industries.

Southern California Gas is the nations largest natural gas utility in terms of the number of industrial gas customers served. It has a long track record of RD&C involvement in line with its mission of providing efficient and environmentally responsible equipment to customers within a service territory controlled by the tightest of air emission standards. Southern California Gas has co-funded and monitored energy usage and air emissions in many field tests at end-user sites in a constant effort to maintain a state-of-the-art status for gaseous-fueled equipment in the demanding South Coast Air Basin. 

The CARB is a department of the California Environmental Protection Agency. CARB’s mission is to promote and protect public health, welfare, and ecological resources through effective reduction of air pollutants while recognizing and considering effects on the economy. The CARB oversees all air pollution control efforts in California to attain and maintain health-based air quality standards.

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