Figure: 30 TAC §117.115(f)(4)

§117.115(f) OPT-IN UNITS

Equipment Class/Description Emission Specification

fluid catalytic cracking unit carbon monoxide (CO) boilers 50% NO_X reduction across the inlet of the CO
boiler to the outlet of the CO boiler, with the
outlet concentration in ppmv converted into
lb/MMBtu of heat input

lean-burn, gas-fired, stationary, reciprocating
internal combustion engines rated 150
horsepower or greater 5.0 g/hp-hr of NO_X under all operating
conditions

boilers or process heaters with a maximum
rated capacity (MRC):
40 million British thermal units per hour
(MMBtu/hr) ≤ MRC< 100 MMBtu/hr the emission specifications in §117.105(a)
of this title for the applicable type of unit

stationary gas turbines with a megawatt (MW)
rating:
1.0 MW ≤ MW rating < 10.0 MW 42 ppmv NO_X at 15% O₂, dry basis

boilers and industrial furnaces that are
regulated as existing facilities by 40 Code of
Federal Regulations Part 266, Subpart H the appropriate emission specification in
§117.105(b) of this title

Equipment Class/Description	Emission Specification
fluid catalytic cracking unit carbon monoxide (CO) boilers	50% NO_X reduction across the inlet of the CO boiler to the outlet of the CO boiler, with the outlet concentration in ppmv converted into lb/MMBtu of heat input
lean-burn, gas-fired, stationary, reciprocating internal combustion engines rated 150 horsepower or greater	5.0 g/hp-hr of NO_X under all operating conditions
boilers or process heaters with a maximum rated capacity (MRC): 40 million British thermal units per hour (MMBtu/hr) ≤ MRC< 100 MMBtu/hr	the emission specifications in §117.105(a) of this title for the applicable type of unit
stationary gas turbines with a megawatt (MW) rating: 1.0 MW ≤ MW rating < 10.0 MW	42 ppmv NO_X at 15% O₂, dry basis
boilers and industrial furnaces that are regulated as existing facilities by 40 Code of Federal Regulations Part 266, Subpart H	the appropriate emission specification in §117.105(b) of this title