API MPMS CH 19.4

Description

Provides methodology to estimate emissions of individual hydrocarbon species using the total emissions of multicomponent hydrocarbon mixtures (such as crude oils and gasoline) estimated from API MPMS Ch. 19.1 for fixed-roof tanks, API MPMS Ch. 19.2 for floating-roof tanks, API MPMS Ch. 19.5 for marine vessels, and many other methods used for total hydrocarbon emission estimates. This process is referred to as speciation.
Speciation of emissions from hydrocarbon mixtures accounts for the higher evaporation rate of the more volatile components, resulting in a different composition of the mixture in the vapor phase than in the liquid phase. The methodology presented in this standard assumes that there is sufficient liquid present such that the chemical composition at the liquid surface may be considered to not change as a result of the evaporative loss.
This standard also contains reference information used for estimating emissions in accordance with API MPMS Ch. 19.1 and 19.2, and API