Coupling of Elements of Chemical-Technological System Operating Under Vacuum (On the Example of Amine Mixture Rectification Unit)

Design of vacuum generation systems for technological installations is a time-consuming task, the solution of which is impossible without the use of mathematical modeling and computer technology. Application of modeling programs of chemical-technological systems allows to reduce significantly the time of designing, facilitates the analysis of more variants of arrangement of elements of the system, and also facilitates the account of influence of elements of the system on each other. The purpose of this study was to develop a methodology for coupled modeling of a complex chemical-technological system operating under vacuum and to apply it to the design of an operating production facility. The vacuum system of the amine mixture separation unit was chosen as the object of research. The system consists of two series-connected vacuum pumps of Rust type and a forevacuum stage - liquid ring vacuum pump. Coupling of properties of the technological object and vacuum generation system implies coordination of their main characteristics, which are the main parameters describing the operating conditions of these units as a whole. To determine intermediate pressures and select equipment sizes, a computer model of a Rust-type vacuum pump was developed in the Aspen HYSYS V12 software package using user modules, and the calculated suction pressures in the stage were imported through a specially developed external control program. After the calculation, the main and auxiliary equipment was selected according to the selected pressures, and the total system capacity was calculated as a function of the suction pressures. The proposed variant of the vacuum system layout will allow to exclude formation of chemically contaminated condensate, reduce the consumption of recycled water by 11 times, while reducing carbon dioxide emissions by 66%.