Computational technology for calculation thermodynamic equlibrium of oil vapors and inert gases in the tank of oil tanker on the basis of the ASPEN HYSYS 2006 package (In English)
During the loading of oil tankers, a significant quantity of light components of crude oil evaporates. These vapors, called volatile organic compounds, consist of: methane, ethane, propane, butane, pentane and a small fraction of heavier hydrocarbons. To ensure fire safety, a mixture of inert gases (IG) which are the purified exhaust gases from the ship's boiler plant, goes into the gas space of the cargo tanks. The ability to estimate the volume of evaporated oil, the vapor density, the component composition of the separated part of hydrocarbons and the composition of the mixture in the tank is an important task. In this paper, computational technology is presented, and the results of calculations for determining the thermodynamic equilibrium of a mixture of oil and inert gases in an oil tank vessel are suitable for any time of discharging or loading the vessel, taking into account the loading rate, ambient temperature and pressure inside the tank. The application of technology for controlling the discharge process is described with the aim of minimizing emissions of oil vapors into the atmosphere. The calculations were carried out on the basis of the ASPEN HYSYS 2006 package for calculation the thermodynamic equilibrium.