Combination of Gibbs and Helmholtz Energy Equations of State in a Multiparameter Mixture Model Using the IAPWS Seawater Model as an Example

Abstract For carbon capture and storage (CCS) applications different sets of equations state are used to describe the whole CCS-chain. While for transport pipeline sections highly accurate (EOS) explicit in Helmholtz energy used, properties under typical geological conditions described by more simple, mostly cubic EOS, brines Gibbs models. Combining leads inconsistent calculations. Since models formulated independent variables (temperature density versus temperature pressure), mass balances challenging equilibria injection region difficult model. To overcome these limitations, a predictive combination energy-based IAPWS seawater model (IAPWS R13-08, 2008) with multi-parameter EOS is presented within this work. The work based on EOS-CG-2016 Gernert Span (J Chem Thermodyn 93:274–293, 10.1016/j.jct.2015.05.015 , 2016). results prove that consistent two possible. Furthermore, it shown, complex brine needs be combined calculations at conditions.