Demfer, so, in the case of the mini-brew system, that doesn't really condone sealed units, there is still no possibility of evaporation because of the blanket of CO2? Air is required for evaporation?
It comes down to the fact that you need heat for evaporation phase change. The density and of a C02 blanket with the concentration of air pressure outside of the fermenter allows for a solid retention. For our purposes evaporation is minimal. Many factors influence evaporation:
Temperature: In spite of the occurrence of evaporation at all temperatures, as the temperature increases, the rate of evaporation increases. Increase in the temperature results in the increase of kinetic energy acquiring sufficient energy for escape into the vapour phase.
Intermolecular forces of the liquid: When the intermolecular forces in a liquid are weak, escape of molecules is easier from the surface resulting in an increase in the rate of evaporation. At high intermolecular forces between molecules in a liquid, only those molecules escape, which have sufficient energy to overcome the intermolecular attraction.
Surface area: The area that is exposed to evaporation directly influences the rate of evaporation. Larger the surface area, greater is the rate of evaporation of the liquid.
Heat: The vibrations within the molecules of hot liquid are very high and hence result in easier escape from the surface of the liquid.
Nature of the liquid: The liquid that contains large charged molecules result in a slow evaporation process with the requirement of additional energy for overcoming the electromagnetic interactions that allow the molecules to escape.
Gaseous molecules: The amount of molecules in the gaseous phase that is present surrounding the liquid molecules, the number of molecules that escape from the surface of the liquid is higher when the number of gas molecules present is high.
Introducing the liquid to vacuum instantly removes the gas before getting converting back to the liquid state, resulting in an enormous rate of evaporation.
The density of the liquid is inversely related to the rate of evaporation. The higher the density of the liquid, the rate of evaporation is slow.
Rate of airflow: Movement of fresh air over the substance increases the concentration of the substance in the air resulting in an increased rate of evaporation.
Concentration of the substance: The concentration of the substance that is evaporating directly influences the evaporation rate and the presence of impurities inversely influences the rate of evaporation.
