Extension of Models to Cover the Phase Behavior and Hydrate Formation Potential of Humid CO₂-Rich Streams at Conditions Relevant to CCS

Models for mutual solubility of water and gas-oil components and hydrate formation are typically tuned to mixtures containing a free water phase. However, CO₂-rich streams in CCS projects are commonly undersaturated with water. If the CO₂ stream is injected into a reservoir and meets an aquifer, the CO₂ will dissolve and form a mutually saturated system. Therefore, models used for designing CCS applications should consider saturated and undersaturated scenarios using a single set of parameters to ensure a seamless examination of all aspects. This work presents equations of state that were tuned to CO₂-water data reflecting CCS process requirements.