This model is used to calculate the emissions associated with the generation
of a non-condensable gas as the result of a chemical reaction. The model assumes
that the gas is exposed to the VOC, becomes saturated with the VOC vapor at the
exit temperature, and leaves the system. The model also assumes that the system
pressure is 760 mmHg, atmospheric pressure. This model is identical to the Gas
Sweep model, except that the non-condensable sweep gas (usually nitrogen) is replaced
in this model by a non-condensable gas generated in situ. It is important to note that
if the generated gas is itself a VOS, non-VOS or TVOS, then the emission of this gas
must be accounted for by a separate model, usually the Mass Balance model.
For example, if n-butyllithium is used in a chemical reaction and generates butane
gas as a byproduct, the evolution of butane gas causes emissions of the VOC present in
the system. These emissions can be modeled by the Gas Evolution model (to account for
the emission of the VOC vapor which saturates the butane gas) and the Mass Balance
model (to account for the emission of the VOC butane).