1065.660 THC, NMHC, NMNEHC, CH4, and C2H6 determination.
§ 1065.660 THC, NMHC, NMNEHC, CH4, and C2H6 determination.
(a) THC determination and initial THC/CH4
contamination corrections. (1) If we require you to
determine THC emissions, calculate xTHC[THC-FID]cor using
the initial THC contamination concentration
xTHC[THC-FID]init from § 1065.520 as follows:
(2) For the NMHC determination described in paragraph (b) of
this section, correct xTHC[THC-FID] for initial THC
contamination using Eq. 1065.660-1. You may correct
xTHC[NMC-FID] for initial contamination of the CH4 sample
train using Eq. 1065.660-1, substituting in CH4 concentrations for
THC.
(3) For the NMNEHC determination described in paragraph (c) of
this section, correct xTHC[THC-FID] for initial THC
contamination using Eq. 1065.660-1. You may correct
xTHC[NMC-FID] for initial contamination of the CH4 sample
train using Eq. 1065.660-1, substituting in CH4 concentrations for
THC.
(4) For the CH4 determination described in paragraph (d) of this
section, you may correct xTHC[NMC-FID] for initial THC
contamination of the CH4 sample train using Eq. 1065.660-1,
substituting in CH4 concentrations for THC.
(b) NMHC determination. Use one of the following to
determine NMHC concentration, xNMHC:
(1) If you do not measure CH4, you may omit the calculation of
NMHC concentrations and calculate the mass of NMHC as described in
§ 1065.650(c)(5).
(2) For nonmethane cutters, calculate xNMHC using the
nonmethane cutter's penetration fraction (PF) of CH4 and the
response factor penetration fraction (RFPF) of C2H6 from §
1065.365, the response factor (RF) of the THC FID to CH4
from § 1065.360, the initial THC contamination and dry-to-wet
corrected THC concentration xTHC[THC-FID]cor as determined
in paragraph (a) of this section, and the dry-to-wet corrected CH4
concentration xTHC[NMC-FID]cor optionally corrected for
initial THC contamination as determined in paragraph (a) of this
section.
(i) Use the following equation for penetration fractions
determined using an NMC configuration as outlined in §
1065.365(d):
Where:
xNMHC = concentration of NMHC. xTHC[THC-FID]cor =
concentration of THC, initial THC contamination and dry-to-wet
corrected, as measured by the THC FID during sampling while
bypassing the NMC. xTHC[NMC-FID]cor = concentration of THC,
initial THC contamination (optional) and dry-to-wet corrected, as
measured by the NMC FID during sampling through the NMC.
RFCH4[THC-FID] = response factor of THC FID to CH4,
according to § 1065.360(d). RFPFC2H6[NMC-FID] = nonmethane
cutter combined ethane response factor and penetration fraction,
according to § 1065.365(d). Example: xTHC[THC-FID]cor =
150.3 µmol/mol xTHC[NMC-FID]cor = 20.5 µmol/mol
RFPFC2H6[NMC-FID] = 0.019 RFCH4[THC-FID] = 1.05
xNMHC = 131.4 µmol/mol
(ii) For penetration fractions determined using an NMC
configuration as outlined in section § 1065.365(e), use the
following equation:
Where:
xNMHC = concentration of NMHC. xTHC[THC-FID]cor =
concentration of THC, initial THC contamination and dry-to-wet
corrected, as measured by the THC FID during sampling while
bypassing the NMC. PFCH4[NMC-FID] = nonmethane cutter CH4
penetration fraction, according to § 1065.365(e).
xTHC[NMC-FID]cor = concentration of THC, initial THC
contamination (optional) and dry-to-wet corrected, as measured by
the THC FID during sampling through the NMC. PFC2H6[NMC-FID]
= nonmethane cutter ethane penetration fraction, according to §
1065.365(e). Example: xTHC[THC-FID]cor = 150.3 µmol/mol
PFCH4[NMC-FID] = 0.990 xTHC[NMC-FID]cor = 20.5
µmol/mol PFC2H6[NMC-FID] = 0.020 xNMHC =
132.3 µmol/mol
(iii) For penetration fractions determined using an NMC
configuration as outlined in section § 1065.365(f), use the
following equation:
Where:
xNMHC = concentration of NMHC. xTHC[THC-FID]cor =
concentration of THC, initial THC contamination and dry-to-wet
corrected, as measured by the THC FID during sampling while
bypassing the NMC. PFCH4[NMC-FID] = nonmethane cutter CH4
penetration fraction, according to § 1065.365(f).
xTHC[NMC-FID]cor = concentration of THC, initial THC
contamination (optional) and dry-to-wet corrected, as measured by
the THC FID during sampling through the NMC.
RFPFC2H6[NMC-FID] = nonmethane cutter CH4 combined ethane
response factor and penetration fraction, according to §
1065.365(f). RFCH4[THC-FID] = response factor of THC FID to
CH4, according to § 1065.360(d). Example: xTHC[THC-FID]cor =
150.3 µmol/mol PFCH4[NMC-FID] = 0.990
xTHC[NMC-FID]cor = 20.5 µmol/mol RFPFC2H6[NMC-FID] =
0.019 RFCH4[THC-FID] = 0.980 xNMHC =
132.5 µmol/mol
(3) For a GC-FID or FTIR, calculate xNMHC using the THC
analyzer's response factor (RF) for CH4, from § 1065.360,
and the initial THC contamination and dry-to-wet corrected THC
concentration xTHC[THC-FID]cor as determined in paragraph
(a) of this section as follows:
Where:
xNMHC = concentration of NMHC. xTHC[THC-FID]cor =
concentration of THC, initial THC contamination and dry-to-wet
corrected, as measured by the THC FID. RFCH4[THC-FID] =
response factor of THC-FID to CH4. xCH4 = concentration of
CH4, dry-to-wet corrected, as measured by the GC-FID or FTIR.
Example: xTHC[THC-FID]cor = 145.6 µmol/mol
RFCH4[THC-FID] = 0.970 xCH4 = 18.9 µmol/mol
xNMHC = 145.6−0.970 · 18.9 xNMHC = 127.3 µmol/mol
(4) For an FTIR, calculate xNMHC by summing the
hydrocarbon species listed in § 1065.266(c) as follows:
Where:
xNMHC = concentration of NMHC. xHCi = the
C1-equivalent concentration of hydrocarbon species i as
measured by the FTIR, not corrected for initial contamination.
xHCi-init = the C1-equivalent concentration of the initial
system contamination (optional) of hydrocarbon species i,
dry-to-wet corrected, as measured by the FTIR. Example:
xC2H6 = 4.9 µmol/mol xC2H4 = 0.9 µmol/mol
xC2H2 = 0.8 µmol/mol xC3H8 = 0.4 µmol/mol
xC3H6 = 0.5 µmol/mol xC4H10 = 0.3 µmol/mol
xCH2O = 0.8 µmol/mol xC2H4O = 0.3 µmol/mol
xC2H2O2 = 0.1 µmol/mol xCH4O = 0.1 µmol/mol
xNMHC = 4.9 + 0.9 + 0.8 + 0.4 + 0.5 + 0.3 + 0.8 + 0.3 + 0.1
+ 0.1 xNMHC = 9.1 µmol/mol
(c) NMNEHC determination. Use one of the following
methods to determine NMNEHC concentration, xNMNEHC:
(1) If the content of your test fuel contains less than 0.010
mol/mol of ethane, you may omit the calculation of NMNEHC
concentrations and calculate the mass of NMNEHC as described in §
1065.650(c)(6).
(2) For a GC-FID or FTIR, calculate xNMNEHC using the THC
analyzer's response factors (RF) for CH4 and C2H6, from §
1065.360, and the initial contamination and dry-to-wet corrected
THC concentration xTHC[THC-FID]cor as determined in
paragraph (a) of this section as follows:
Where:
xNMNEHC = concentration of NMNEHC. xTHC[THC-FID]cor =
concentration of THC, initial THC contamination and dry-to-wet
corrected, as measured by the THC FID. RFCH4[THC-FID] =
response factor of THC-FID to CH4. xCH4 = concentration of
CH4, dry-to-wet corrected, as measured by the GC-FID or FTIR.
RFC2H6[THC-FID] = response factor of THC-FID to C2H6.
xC2H6 = the C1-equivalent concentration of C2H6, dry-to-wet
corrected, as measured by the GC-FID or FTIR. Example:
xTHC[THC-FID]cor = 145.6 µmol/mol RFCH4[THC-FID] =
0.970 xCH4 = 18.9 µmol/mol RFC2H6[THC-FID] = 1.02
xC2H6 = 10.6 µmol/mol xNMHC = 145.6 - 0.970 · 18.9 -
1.02 · 10.6 xNMHC = 116.5 µmol/mol
(3) For an FTIR, calculate xNMNEHC by summing the
hydrocarbon species listed in § 1065.266(c) as follows:
Where:
xNMNEHC = concentration of NMNEHC. xHCi = the
C1-equivalent concentration of hydrocarbon species i as
measured by the FTIR, not corrected for initial contamination.
xHCi-init = the C1-equivalent concentration of the initial
system contamination (optional) of hydrocarbon species i,
dry-to-wet corrected, as measured by the FTIR. Example:
xC2H4 = 0.9 µmol/mol xC2H2 = 0.8 µmol/mol
xC3H8 = 0.4 µmol/mol xC3H6 = 0.5 µmol/mol
xC4H10 = 0.3 µmol/mol xCH2O = 0.8 µmol/mol
xC2H4O = 0.3 µmol/mol xC2H2O2 = 0.1 µmol/mol
xCH4O = 0.1 µmol/mol xNMNEHC = 0.9 + 0.8 + 0.4 + 0.5
+ 0.3 + 0.8 + 0.3 + 0.1 + 0.1 xNMNEHC = 4.2 µmol/mol
(d) CH4 determination. Use one of the following
methods to determine CH4 concentration, xCH4:
(1) For nonmethane cutters, calculate xCH4 using the
nonmethane cutter's penetration fraction (PF) of CH4 and the
response factor penetration fraction (RFPF) of C2H6 from §
1065.365, the response factor (RF) of the THC FID to CH4
from § 1065.360, the initial THC contamination and dry-to-wet
corrected THC concentration xTHC[THC-FID]cor as determined
in paragraph (a) of this section, and the dry-to-wet corrected CH4
concentration xTHC[NMC-FID]cor optionally corrected for
initial THC contamination as determined in paragraph (a) of this
section.
(i) Use the following equation for penetration fractions
determined using an NMC configuration as outlined in §
1065.365(d):
Where:
xCH4 = concentration of CH4. xTHC[NMC-FID]cor =
concentration of THC, initial THC contamination (optional) and
dry-to-wet corrected, as measured by the NMC FID during sampling
through the NMC. xTHC[THC-FID]cor = concentration of THC,
initial THC contamination and dry-to-wet corrected, as measured by
the THC FID during sampling while bypassing the NMC.
RFPFC2H6[NMC-FID] = the combined ethane response factor and
penetration fraction of the nonmethane cutter, according to §
1065.365(d). RFCH4[THC-FID] = response factor of THC FID to
CH4, according to § 1065.360(d). Example: xTHC[NMC-FID]cor =
10.4 µmol/mol xTHC[THC-FID]cor = 150.3 µmol/mol
RFPFC2H6[NMC-FID] = 0.019 RFCH4[THC-FID] = 1.05
xCH4 = 7.69 µmol/mol
(ii) For penetration fractions determined using an NMC
configuration as outlined in § 1065.365(e), use the following
equation:
Where:
xCH4 = concentration of CH4. xTHC[NMC-FID]cor =
concentration of THC, initial THC contamination (optional) and
dry-to-wet corrected, as measured by the NMC FID during sampling
through the NMC. xTHC[THC-FID]cor = concentration of THC,
initial THC contamination and dry-to-wet corrected, as measured by
the THC FID during sampling while bypassing the NMC.
PFC2H6[NMC-FID] = nonmethane cutter ethane penetration
fraction, according to § 1065.365(e). RFCH4[THC-FID] =
response factor of THC FID to CH4, according to § 1065.360(d).
PFCH4[NMC-FID] = nonmethane cutter CH4 penetration fraction,
according to § 1065.365(e). Example: xTHC[NMC-FID]cor = 10.4
µmol/mol xTHC[THC-FID]cor = 150.3 µmol/mol
PFC2H6[NMC-FID] = 0.020 RFCH4[THC-FID] = 1.05
PFCH4[NMC-FID] = 0.990 xCH4 = 7.25
µmol/mol
(iii) For penetration fractions determined using an NMC
configuration as outlined in § 1065.365(f), use the following
equation:
Where:
xCH4 = concentration of CH4. xTHC[NMC-FID]cor =
concentration of THC, initial THC contamination (optional) and
dry-to-wet corrected, as measured by the NMC FID during sampling
through the NMC. xTHC[THC-FID]cor = concentration of THC,
initial THC contamination and dry-to-wet corrected, as measured by
the THC FID during sampling while bypassing the NMC.
RFPFC2H6[NMC-FID] = the combined ethane response factor and
penetration fraction of the nonmethane cutter, according to §
1065.365(f). PFCH4[NMC-FID] = nonmethane cutter CH4
penetration fraction, according to § 1065.365(f).
RFCH4[THC-FID] = response factor of THC FID to CH4,
according to § 1065.360(d). Example: xTHC[NMC-FID]cor = 10.4
µmol/mol xTHC[THC-FID]cor = 150.3 µmol/mol
RFPFC2H6[NMC-FID] = 0.019 PFCH4[NMC-FID] = 0.990
RFCH4[THC-FID] = 1.05 xCH4 = 7.78
µmol/mol
(2) For a GC-FID or FTIR, xCH4 is the actual dry-to-wet
corrected CH4 concentration as measured by the analyzer.
(e) C2H6 determination. For a GC-FID or
FTIR, xC2H6 is the C1-equivalent, dry-to-wet corrected C2H6
concentration as measured by the analyzer.
[76 FR 57462, Sept. 15, 2011, as amended at 81 FR 74184, Oct. 25,
2016]