TITLE 40 - PROTECTION OF ENVIRONMENT

CHAPTER I - ENVIRONMENTAL PROTECTION AGENCY

SUBCHAPTER U - AIR POLLUTION CONTROLS

PART 1065 - ENGINE - TESTING PROCEDURES

subpart g - CALCULATIONS AND DATA REQUIREMENTS

1065.660 - THC and NMHC determination.

  (a) THC determination. If we require you to determine THC emissions, calculate xTHC using the initial THC contamination concentration xTHCinit from 1065.520 as follows: (image) Example: xTHCuncor = 150.3 mol/mol xTHCinit = 1.1 mol/mol xTHCcor = 150.3 1.1 xTHCcor = 149.2 mol/mol (b) NMHC determination. Use one of the following to determine NMHC emissions, xNMHC.

  (1) Report xNMHC as 0.98 · xTHC if you did not measure CH4, or if the result of paragraph (b)(2) or (3) of this section is greater than the result using this paragraph (b)(1).

  (2) For nonmethane cutters, calculate xNMHC using the nonmethane cutter's penetration fractions (PF) of CH4 and C2H6 from 1065.365, and using the initial NMHC contamination concentration xNMHCinit from 1065.520 as follows: (image) Where: xNMHC = concentration of NMHC.

PFCH4 = nonmethane cutter CH4 penetration fraction, according to 1065.365.

xTHC = concentration of THC, as measured by the THC FID.

RFCH4 = response factor of THC FID to CH4, according to 1065.360.

xCH4 = concentration of methane, as measured downstream of the nonmethane cutter.

PFC2H6 = nonmethane cutter CH4 penetration fraction, according to 1065.365.

xNMHCinit = initial NMHC contamination concentration, according to 1065.520.

Example: PFCH4 = 0.990 xTHC = 150.3 mol/mol RFCH4 = 1.05 xCH4 = 20.5 mol/mol PFC2H6 = 0.020 xNMHCinit = 1.1 mol/mol (image) xNMHC = 130.1 mol/mol (3) For a gas chromatograph, calculate xNMHC using the THC analyzer's response factor (RF) for CH4, from 1065.360, and using the initial NMHC contamination concentration xNMHCinit from 1065.520 as follows: (image) Example: xTHC = 145.6 mol/mol RFCH4 = 0.970 xCH4 = 18.9 mol/mol xNMHCinit = 1.1 mol/mol xNMHC = 145.6 0.970 · 18.9 1.1 xNMHC = 126.2 mol/mol