Appendix XVI to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles Equipped With Periodically Regenerating Trap Oxidizer Systems Certifying to the Provisions of Part 86, Subpart R

Link to an amendment published at 79 FR 23746, Apr. 28, 2014.

(a) Gaseous-Fueled Vehicle Pollutant Mass Emission Calculation Procedure.

(1) For all TLEVs, LEVs, and ULEVs, the calculation procedures specified in Chapter 5 of the California Regulatory Requirements Applicable to the National Low Emission Vehicle Program (October, 1996) shall apply. These procedures are incorporated by reference (see §86.1).

(b) Pollutant Mass Emissions Calculation Procedure for Vehicles Equipped with Periodically Regenerating Trap Oxidizer Systems.

(1) Exhaust Emissions. (i) The provisions of §86.1777 apply to vehicles equipped with periodically regenerating trap oxidizer systems, except that the following shall apply instead of the requirements in §86.144-94(a):

(ii) The final reported test results shall be computed by the use of the following formula:

(iii) For light-duty vehicles and light-duty trucks:

Ywm = 0.43 ((Yct + Ys) / (Dct + Ds)) + 0.57 ((Yht + Ys) / (Dht + Ds)).

(iv) For purposes of adjusting emissions for regeneration:

Re = ((Yr1 − Yct) + (Yr2 − Ys) + (Yr3 − Yht)) / (Dct + Ds + Dht).

Yr = Ywm + Re.

Ywm = Weighted mass emissions of each pollutant, i.e., HC, CO, NOX or CO , in grams per vehicle mile.

Yct = Mass emissions as calculated from the “transient” phase of the cold start test, in grams per test phase.

Yht = Mass emissions as calculated from the “transient” phase of the hot start test in grams per test phase.

Ys = Mass emissions as calculated from the “stabilized” phase of the cold start test, in grams per test phase.

Dct = The measured driving distance from the “transient” phase of the cold start test, in miles.

Dht = The measured distance from the “transient” phase of the hot start test, in miles.

Ds = The measured driving distance from the “stabilized” phase of the cold start test, in miles.

Yr = Regeneration emission test.

Re = Mass emissions of each pollutant attributable to regeneration in grams per mile.

Yr1 = Mass emissions, during a regeneration emission test, as calculated from the “transient” phase of the cold start test, in grams per test phase.

Yr2 = Mass emissions, during a regeneration emission test, as calculated from the “stabilized” phase of the cold start test, in grams per test phase.

Yr3 = Mass emissions, during a regeneration emission test, as calculated from the “transient” phase of the hot start test in grams per test phase.

(2) Particulate Emissions. (i) The provisions of §86.1778 apply to vehicles equipped with periodically regenerating trap oxidizer systems, except that the following shall apply instead of the requirements §86.145-82(a):

(ii) The final reported test results for the mass particulate (Mp) in grams/mile shall be computed as follows.

(iii) For purposes of adjusting emissions for regeneration:

Mp = 0.43(Mp1 + Mp2) / (Dct + Ds) + 0.57 (Mp3 + Mp2) / (Dht + Ds)

Re = ((Mpr1 − Mp1) + (Mpr2 − Mp2) + (Mpr3 − Mp3) / (Dct + Ds + Dht)

Mpr = Mp + Re

(1) Mp1 = Mass of particulate determined from the “transient” phase of the cold start test, in grams per test phase. (See §86.110-94(d)(1) for determination.)

(2) Mp2 = Mass of particulate determined from the “stabilized” phase of the cold start test, in grams per test phase. (See §86.110-94(d)(1) for determination.)

(3) Mp3 = Mass of particulate determined from the “transient” phase of the hot start test, in grams per test phase. (See §86.110-94(d)(1) for determination.)

(4) Dct = The measured driving distance from the “transient” phase of the cold start test, in miles.

(5) Ds = The measured driving distance from the “stabilized” phase of the cold start test, in miles.

(6) Dht = The measured driving distance from the “transient” phase of the hot start test, in miles.

(7) Mpr = Regeneration emission test

(8) Re = Mass of particulate attributable to regeneration in grams/mile.

(9) Mpr1 = Mass of particulate determined, during a regeneration emission test, from the “transient” phase of the cold start test in grams per test phase. (See §86.110-94(d)(1) for determination.)

(10) Mpr2 = Mass of particulate determined, during a regeneration emission test, from “stabilized” phase of the cold start test, in grams per test phase. (See §86.110-94(d)(1) for determination.)

(11) Mpr3 = Mass of particulate determined, during a regeneration emission test, from the “transient” phase of the hot start test, in grams per test phase. (See §86.110-94(d)(1) for determination.)

(c) Fuel Economy Calculations for Gaseous Fuels Based on the Cold Start CVS-1975 Federal Test Procedure.

(1) Assume the fuel meets HD-5 specifications (95% C3H8, 5% nC4H10, by volume).

(i) Physical constants of Propane and Normal Butane:

Component	Mol. Wt.	Sp. Gr.	Liquid density (lb/gal @ 60 °F)				Liquid density of Hd-5 (lb/gal @ 60 °F)
C3H8	44.094	0.508	4.235	×	0.95	=	4.0233
nC4H10	58.12	0.584	4.868	×	0.05	=	0.2434
							___
							4.2667

(ii) Density of the HD-5 fuel:

(0.95 × 4.235) + (0.05 × 4.868) = 4.267 lb/gal @ 60 °F

(iii) Molecular Weights:

(A)

Species	Mol. Wt.
C	12.01115
H	1.00797
0	15.9994
CO	28.01055
CO2	44.00995
CH2.658*	14.6903

*Average ratio of Hydrogen to carbon atoms in HD-5 fuel.

(B)

C3H8	8/3	=	2.666×0.95 (% propane)	=	2.533
nC4H10	10/4	=	2.5×0.05 (% Butane)	=	0.125
					2.568

(iv) Weight of Carbon in:

CO = wt. of CO × (12.01115 / 28.01055) = wt CO × (0.429)

CO2 = wt. of CO2 × (12.01115 / 44.00995) wt CO2 × (0.273)

CH2.658 = wt. of CH2.658 × (12.01115 / 14.6903) = wt CH2.658 × (0.818)

(v) Wt. of Carbon per gallon of LPG:

wt. of carbon = 4.2667 lbs/gal × 453.59 gms/lb × 0.818 = 1583 grams C/gal HD-5

(vi) Fuel economy:

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HC = CVS HC in grams/mile

CO = CVS CO in grams/mile

CO2 = CVS CO2 in grams/mile

For gasoline:

= 2421 / ((0.866)(HC) + (0.429)(CO) + (0.273)(CO2))

For Natural Gas:

= 1535 / ((0.759)(HC) + (0.429)(CO) + (0.273)(CO2))

[62 FR 31265, June 6, 1997]