Aspen Plus ENRTL Model for HS3 Blend, a Novel Solvent for CO₂ Capture

Carbon Capture and Storage (CCS) is among the main available options to cut CO₂ emissions from the industry and energy production sectors, but the high costs of current CCS technology still limit their large-scale applicability. For this reason, there is increasing interest in alternative absorbents with the potential to lower the energy and environmental impact of carbon capture. The estimation of costs, as well as process design and optimization, require accurate, reliable, and stable thermodynamic models. This article presents the development and testing of an ELECNRTL model in Aspen Plus for the characterization of HS3, an innovative blend made up of a primary (3-amino-1-propanol) and a tertiary (1-(2-hydroxyethyl) pyrrolidine) amine studied in the H2020-funded Realise project. The vapor-liquid equilibrium (VLE) model is fitted to in-house experimental data covering a wide range of loadings and operating temperatures. A plot for the system speciation in the liquid phase is obtained. Moreover, a comparison between the heat of absorption data and model prediction is also included. The proposed VLE model shows good accuracy and numerical stability in the whole temperatures and loading ranges of interest for industrial CO₂ capture applications.