2024 AIChE Annual Meeting
(249g) A Framework to Predict the Formation of Strong Acids in CO2 Transportation Systems
Authors
Ronald Springer, OLI Systems, Inc.
Jiangping Liu, OLI Systems Inc
Mohiedin Bagheri Hariri, Ohio University
Andrzej Anderko, Oli Systems Inc
Carbon dioxide transportation is the critical link between carbon capture and carbon storage. Until recently, the challenges associated with CO2 transport have been largely neglected; however, there is now increasing reference to Carbon Capture, Transport, Utilization, and Storage (CCTUS) instead of just CCUS. Among the most significant challenges for achieving safe, cost-effective CO2 transport is understanding how impurities in CO2 streams can affect pipeline integrity. Research has shown that the formation of strong acids, such as sulfuric and nitric acids, due to reactions between impurities are corrosive to CO2 transport pipeline materials like carbon steel. To understand the corrosive potential of different impurities and the likelihood of acid drop out, we present a comprehensive thermodynamic model based on the previously developed Mixed-Solvent Electrolyte (MSE) framework, to describe the speciation and phase equilibria in both CO2-rich and water-rich environments. Utilizing recent measurements of H2SO4/HNO3 solubility in dense CO2 phase, in conjunction with available literature data, our model offers predictive capabilities regarding the oxidation and reduction reactions among impurities such as NOx, SOx, H2S etc. Notably, our model’s predictions agree with experimental measurements of the impurity speciation at different oxygen levels. Therefore, this model can provide significant insight to assess the acceptable level of impurities under various conditions encountered in CO2 transportation. In addition, this model can be used to help plan pipeline networks where multiple streams from different CO2 sources and impurity profiles will come together into major trunk lines for transport to large scale geologic storage sites.