Running loss emissions

Application of Canisters in Running Loss Emission Control... 

The key sources of evaporative emissions during drive cycles are running loss emissions, hot soak emissions, and diurnal emissions. 

The latest CARB/EPA procedures require diurnal emissions to be measured during a real time, three day test that exposes the complete vehicle to daily temperature fluctuations. This test method has been employed to more accurately reflect the real world diurnal emissions that occur. Running loss emission measurements were also initiated in the latest test procedures. Evaporative emissions are measured... 

In addition to very low exhaust emissions, CNG vehicles also have the advantage of no evaporative emissions or running loss emissions9 caused by the fuel. As vehicle exhaust emissions are reduced to meet the most stringent standards, running loss emissions become more important. 

Running loss emissions are emissions from the fuel tank during vehicle operation due to heating of the fuel, losses from the evaporative canister, or losses due to permeation of fuel through elastomeric fuel lines. 

Propane shares several emissions advantages with natural gas and has some additional ones of its own. Like natural gas, propane vehicles do not have any evaporative or running loss emissions associated with the fuel. Unbumed hydrocarbons from propane are easier to oxidize in oxidation catalysts than methane, which results in low unbumed hydrocarbon emissions. Unbumed hydrocarbons from propane are also less reactive by about two-thirds compared to unbumed hydrocarbons from gasoline [1.26]. Being a gas, propane mixes very well with the air before entering the engine, resulting in low carbon monoxide emissions,... 

While the jury may still be out on the exhaust emissions of propane vehicles, it is certain that propane vehicles do not have evaporative or running loss emissions caused by the fuel. As exhaust emissions of vehicles become smaller and... 

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