System and method of reducing pulverizer flammability hazard and boiler nitrous oxide output

A method of reducing nitrous oxide output and reducing pulverizer flammability in a coal-fired steam boiler system, the method comprising:

• receiving a primary air;
• heating a portion of the primary air to yield a heated air having a selected temperature;
• burning a first fuel mixture to produce a flue gas;
• cooling the flue gas;
• cleaning the flue gas utilizing a flue gas filter configured to remove particles from the flue gas to yield a cooled cleaned flue gas;
• recirculating a portion of the cooled cleaned flue gas from the output of the flue gas filter;
• admixing a selected amount of
• (i) the primary air,
• (ii) the heated air of the selected temperature, with
• (iii) the recirculated cooled cleaned flue gas,
• to form a control mixture with a controlled temperature according to a set of predetermined requirements;
• injecting the control mixture into a pulverizer, wherein the contents of the pulverizer include the first fuel air mixture;
• mixing the control mixture with the contents of the pulverizer, to produce a second fuel mixture;
• and
• burning the second fuel mixture in the boiler,
• wherein the second fuel mixture is less flammable than the first fuel mixture, and further
• wherein when the second fuel mixture is burned in the boiler, a reduced nitrous oxide output is achieved.