Calculation of a two-phase system of a liquified hydrocarbon gas

Abstract

Liquefied hydrocarbon gases are a mixture of chemical compounds, consisting mainly of hydrogen and carbon with different molecular structures. The main components of liquefied hydrocarbon gases are propane and butane, containing lighter hydrocarbons (methane and ethane) and heavier ones (pentane) in the form of impurities. All of these components are saturated hydrocarbons. The composition of liquefied hydrocarbon gases can also include unsaturated hydrocarbons: ethylene, propylene, butylene. Butane-butylenes may be present as isomeric compounds (isobutane and isobutylene). When designing and operating liquefied petroleum gas systems, it is necessary to take into account the external equilibrium between the liquid and the gas. The paper analyzes the change in the ratio of components, in which the relative content of lighter hydrocarbons will decrease, while the content of heavier ones will increase. With an intensive flow of gas, the temperature of the liquid will drop sharply, estimation will be disturbed, and the vessel will freeze. Therefore, when operating balloon installations, it is very important to consider safety issues that are associated with containers’ filling, as well as with the change in the composition of hydrocarbon gases mixture. The discussed issues related to the calculation of a two-phase system of liquefied hydrocarbon gas can improve the operating conditions of the systems.