Coupling of Elements of Chemical–Technological System Operating under Vacuum (on the Example of an Amine Mixture Rectification Unit)

The design of vacuum systems for technological installations poses a formidable challenge, necessitating the use of mathematical modeling and computational tools. The application of modeling programs of chemical-technology systems allows the significant reduction in design time, facilitates the analysis of more variants of arrangement of the elements of the system, and also allows analysis of the influence of the elements of the system on each other. This study aims to develop a methodology for coupled modeling of intricate chemical-technology systems operating under vacuum conditions and to employ it in the design of practical industrial processes. The subject of this investigation is the vacuum-generation system in an amine mixture separation unit. The system consists of two series-connected Rust-type vacuum pumps and a forevacuum stage—a liquid ring vacuum pump. The coupling of the properties of the technological object and the 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 the intermediate pressures and equipment sizing, a computational model of the Rust-type vacuum pump is meticulously developed within the Aspen HYSYS V12 software suite, leveraging custom modules. The computed inlet pressures are subsequently incorporated via a purpose-built external-control program. Following calculations based on the chosen inlet pressures, the appropriate main and ancillary equipment are selected, while the overall system performance is meticulously assessed depending on the inlet pressures. The proposed configuration of the vacuum system promises to eliminate the formation of a chemically contaminated condensate, reduce circulating water consumption by a significant factor of 11, and concurrently reduce CO2 emissions by an impressive 66%.