Many state air quality compliance regulations require low NOx boiler emissions below 30 ppm. And in some parts of the country like California, Texas, Louisiana and New Jersey, boiler operators are required to achieve and maintain even more stringent air quality emission standards of ultra low NOx levels (ULN), typically less than 10-12 ppm and as low as single digit NOx levels 5-7 ppm of NOx.
NOx Formation
Thermal NOx is a byproduct of the combustion process that is formed by industrial boilers and process heaters when burning natural gas (and other fuel gases with no bound nitrogen), where high flame temperatures cause nitrogen molecules from the combustion air to combine with oxygen to form nitric oxide. Over the years many industrial facilities and boilers operators have made the change from burning coal or fuel oil to cleaner burning natural gas in an effort to lower NOx, along with reducing fuel costs.
Ultra Low NOx Boilers & Boiler Systems
Ultra low NOx boilers combine energy efficient design and technology to reduce NOx emissions, save on fuel costs and reduce greenhouse gases without affecting performance. Ultra low NOx boilers can utilize several design and equipment solutions to significantly reduce overall nitrogen oxide (NOx) emissions and reach levels as low as 5 ppm:
- Low NOx Burners – Ultralow NOx boiler burners provide stable combustion at lower flame temperatures with lower excess air and offer high turndown (up to 12 to 1 for natural gas), resulting increased combustion efficiency - more energy is available for the load, as less heat from the combustion process is needed to heat combustion air. Depending on the burner style and configuration, some ultra low NOx burners can achieve single digit NOx emissions without the use of flue gas recirculation.
- Flue Gas Recirculation (FGR) – FGR meters a percentage of flue gas, reintroducing it back into the combustion air supply, increasing or decreasing the percentage of FGR based on the amount of reduction in NOx required.
- High Efficiency Boilers – The term “boiler efficiency” refers to thermal efficiency (fuel-to-steam efficiency) of the boiler’s heat exchanger, taking into account radiation and convection losses. High efficiency boilers maximize the transfer of heat from the combustion process to the water or steam in the boiler, keeping fuel requirements lower as a result of optimized performance.
- Advanced Air/Fuel Controls - Our ultralow NOx burners feature advanced controls to deliver extremely precise air to fuel ratio control with excellent repeatability across a variety of fuel types for industrial watertube boilers, firetube boilers and thermal heaters.
Trust the ultra low NOx boiler specialists at IB&M
Industrial Boiler & Mechanical specializes in the sale, installation and service of highly efficient, low and ultra low NOx boilers including firetube and watertube designs. Whether you’re looking for a new ultra low NOx boiler or needing to upgrade an older system, IB&M can help you evaluate the costs associated with purchasing new equipment vs upgrading in order to achieve fuel savings, reduce operating costs, and meet NOx emission compliance requirements.
The team at Industrial Boiler will help you meet EPA emission compliance regulations with a new or upgraded ultra low NOx boiler.