In previous posts, we discussed the Federal EPA rules and how to determine what is an Area Source and a Major Source. The actual enforcement of much of the EPA ruling has been delegated to the state pollution control agencies.
While the Federal EPA has set standards, not all states strictly adhere to the Federal guidelines. Some states have more strictly regulated the emissions and most states require Air Permitting before constructing or installing fossil fuel burning equipment.
Below are links to help you navigate through the individual processes on a state level.
Regardless of the state you are in, the Criteria Air Pollutants most often associated with boilers in commercial and industrial applications are Carbon Monoxide, Sulfur Dioxide, and Nitrogen Dioxides. Depending on the fuel you intend to burn, your state authority may want to limit your boiler emissions on one or more of these pollutants to ensure the facility does not exceed these limits.
Most boiler manufacturers can meet the Carbon Monoxide limits set by regulators, the complexity comes in when trying to control Nitrogen and Sulfur compounds. Control of Sulfur compounds is most difficult, as these compounds are a function of the fuel being burned (fuel bound). If the intent is to burn oil or any liquid fuel, installation of meters to record the amount of oil is a Federal Requirement.
Nitrogen compounds while more easily controlled, the State specified limits frequently will vary depending on the size and location of the installation. Specified Nitrogen compound limits (NOx) can range from 110 ppm down to 5 ppm depending on the facility emitting, and the State of jurisdiction. This instantaneous limit that may be required by your boiler will be used in conjunction with operating parameters to derive an emissions limit in Tons Per Year (TPY) and will be referred to as the Potential To Emit (PTE).
Selecting the right boiler/burner combination to achieve these limits, and the compatibility of the equipment should be closely reviewed. While most boiler/burner combinations can meet basic limits, attainment of more stringent specifications can delve deep into burner design, furnace geometry, excess air, and overall boiler efficiency.