As a result of the EPA’s Clean Air Act, many state and federal environmental regulations require increasingly stringent lower NOx emissions compliance for manufacturing facilities, chemical plants, refineries, and industrial plants dependent on production processes that produce NOx, CO and other VOCs. These facilities are faced with meeting or exceeding low NOx (30 ppm) and even ultralow NOx (<9 ppm) emission requirements, which frequently requires boiler system equipment upgrades or replacement.
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.
Low NOx Boilers & Boiler Equipment
Low NOx boilers provide improved energy efficiency and lower emissions of nitrous oxides. NO and NO2 are toxic atmospheric gases. Our Low NOx boilers combine energy efficiency with NOx-related upgrades and reduce nitrous oxides, save energy and reduce greenhouse gases. Low NOx boilers can utilize several design and equipment solutions to significantly reduce overall nitrogen oxide (NOx) emissions and reach levels under 30 ppm:
- Low NOx Burners – Low NOx boiler burners are designed to maintain stable combustion at lower flame temperatures and offer good turndown. Well-designed low NOx burners operate using a minimum excess air requirement (and leave very little unburned fuel), resulting increased combustion efficiency - more energy is available for the load, as less heat from the combustion process is needed to heat combustion air.
- 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 - One of the factors influencing NOx formation in a boiler is the excess air level. Altering the fuel/air ratio to improve fuel/air distribution and mixing, and limiting the amount of excess O2 entering a flame via oxygen trim controls can help reduce NOx emissions. Advanced controls can deliver extremely precise air to fuel ratio control with excellent repeatability.
Upgrading or Replacing Equipment
Whether you’re looking for a new Low NOx boiler or a retrofit option for an older system, IB&M has the expertise and materials to make this happen with ease. We can help you evaluate the costs associated with purchasing new equipment vs upgrading in order to achieve fuel savings, reduce operating costs, and meet compliance requirements. Deciding the best route to NOx reduction is largely based on:
- Boiler Efficiency & Performance - As stated above, boiler efficiency and the effective transfer of heat is influenced by a number of factors like boiler size and load characteristics, air to fuel ratio burner control accuracy, programmable boiler controls and excess air trim management, low emissions burner technology, turndown, type of fuel, and emission requirements.
- Maintenance Costs - Add up the costs of major maintenance, emergency maintenance and downtime due to equipment age, burner and refractory problems, along with the challenge of parts availability and expense, and time spent keeping units on-line, etc. to better understand the true cost of ownership.
- Fuel Costs - Fuel typically represents the largest expense associated with running a boiler, and can impact boiler efficiency 2% or more in fuels like fuel oil and natural gas which have varying hydrogen content and related water vapor losses.
Maintain peak performance
A Low Nox Boiler System does not have to mean low performance. Upgrading to a Low NOx boiler system lowers your carbon footprint by reducing greenhouse gases, ensuring you meet all state and federal regulations. Numerous states offer incentives for plants converting to Low NOx boilers.
Our boiler systems feature the latest in emission-reduction technology such as microprocessor-based gas and air pre-mix, thermal reduction, and flue gas recirculation. The result is cleaner, more efficient fuel usage and significant operating cost savings.
Industrial Boiler & Mechanical can help you with finding a new or rental low NOx boiler or upgrading existing burners and equipment to meet EPA compliance regulations.