Figure: 30 TAC §117.305(b)(6)

The equation to calculate the time-weighted nitrogen oxides emission limitation for each 30-day period, in pounds per million British thermal units, for gas-fired boilers or process heaters firing gaseous fuel containing more than 50% hydrogen by volume.

Where:

     EL2 =   time-weighted NOX emission limitation for each 30-day period, in lb/MMBtu of heat
                 input

     EL1 =   appropriate NOX emission limitation for gas-fired boilers from §117.305(b)(1)(A) -
                  (F)  of this title or gas-fired process heaters from §117.305(b)(2)(A) and (B) of this
                  section, in lb/MMBtu of heat input;

     1.25 = factor used as a multiplier times the appropriate emission limitation when firing
               gaseous fuel that contains more than 50% hydrogen by volume, over an eight-hour
               period;

     T1 =  time in hours when firing gaseous fuel that contains more than 50% hydrogen by
              volume, over an eight-hour period during each 30-day period. The time period when
              hydrogen rich fuel is combusted must, at a minimum, be a consecutive eight-hour
              period to be used in the determination of T1; and

     T2 =  time in hours when firing gaseous fuel or hydrogen rich fuel (for less than eight
              consecutive hours) during each 30-day period.