2 Method 1, Carbon balance

  2.1 This method includes six steps that shall be used in the calculation of the exhaust gas concentrations with regard to the fuel characteristics.

  2.2 The given formulae of method 1 are only valid in the absence of oxygen in the fuel.

  2.3 First step: Calculation of the stoichiometric air demand

  2.3.1 Process of complete combustion:

(1-1)

(1-2)

(1-3)

(1-4)

  2.4 Second step: Calculation of the excess-air factor based on complete combustion and the CO₂ concentration

(1-5)

  2.5 Third step: Calculation of the hydrogen-to-carbon ratio

(1-6)

  2.6 Fourth step: Calculation of the dry hydrocarbon concentration based on the ECE R49 procedure with respect to fuel characteristics and air-to-fuel ratio

  2.6.1 The conversion of dry to wet concentration is given by:

(1-7)

(1-8)

(1-9)

(1-10)

  2.6.2 The formula results:

(1-11)

and

(1-12)

  2.6.3 The excess air factor is defined as:

(1-13)

(1-14)

(1-15)

(1-16)

(1-17)

(1-18)

  2.7 Fifth step: Calculation of the excess air factor based on the procedures specified in Title 40, United States Code of Federal Regulations (40CFR86.345-79).

(1-19)

(1-20)

  2.8 Sixth step: Calculation of the exhaust mass

(1-21)

(with the excess air factor defined in step four)

(1-22)

(1-23)

(1-24)