§ 1065.810 - Calculations.

(a) THCE emissions. (1) Calculate THCE emissions as the sum of the mass of the nonoxygenated hydrocarbons in the exhaust and the carbon-equivalent mass of each measured oxygenated species in the exhaust.

(2) Calculate carbon-equivalent mass of each measured oxygenated species from the following equation:

Carbon equivalent = 13.8756 × MOC/MWPC

(b) NMHCE emissions. Calculate NMHCE emissions as either:

(1) The sum of the mass of the nonoxygenated nonmethane hydrocarbons in the exhaust and the carbon-equivalent mass of each measured oxygenated species in the exhaust.

(2) THCE minus the mass of methane in the exhaust.

(c) Sample calculation. (1) Assume the following emissions for a test: 40.00 grams of nonoxygenated hydrocarbons, 100.00 grams of ethanol, and 10.00 grams of acetaldehyde, and 1.00 gram of formaldehyde.

(2) The carbon-equivalent of the masses of oxygenated compounds are:

(i) 13.8756 × 100.00/(46.068/2) = 60.24 grams of ethanol.

(ii) 13.8756 × 10.00/(44.052/2) = 6.30 grams of acetaldehyde.

(iii) 13.8756 × 1.00/(30.026) = 0.46 grams of formaldehyde.

(3) THCE = 40.00 + 60.24 + 6.30 + 0.46 = 107.00 grams per test.