Phase equilibria for petroleum reservoir fluids containing water and aqueous methanol solutions: Experimental measurements and modelling using the CPA equation of state

Phase equilibrium for clathrate hydrate formed in methane+water+urea system

“…We [15][16][17].We obtainedphase equilibrium data for these molar concentrations of urea and compared the urea-and methanol-inducedshifts in the equilibrium temperature. These shifts were also compared with those resulting from x = 0.06 of mono-ethylene glycol and ethanol.…”

“…Methanol and monoethylene glycol are two of the strongest polar-molecular THIs, and relatively small dosages of each can lead to shifts in the phase equilibrium curve. [15][16][17][18]Ethanol and propanol are also THIs.However, at temperatures below the freezing point of water,these THIs andmethanol can become guest substancesofclathrate hydrates. [19][20][21] Moreover, the toxicity of polar substancesposes a problem if they are leaked from a closed system or used in an open system such as an ocean;therefore, thedevelopment of low-risk THIs is essential.…”

Gas hydrates in low water content gases: Experimental measurements and modelling using the CPA equation of state

“…A device based upon tuneable diode laser absorption spectroscopy (TDLAS) technology was used to measure the water content of methane and two synthetic multi-component gas mixtures in equilibrium with hydrates at pressures between 5 and 40 MPa and at temperatures between 273.15 and 251.65 K. A thermodynamic model using the well-proven Cubic-Plus-Association equation of state (CPA-EoS) has been employed to model the phase equilibria [5,6]. The thermodynamic model is based on uniformity of fugacity of each component throughout all the phases.…”

Thermodynamic properties and vapor–liquid equilibria of associating fluids, Peng–Robinson equation of state coupled with shield-sticky model

“…The CPA-EOS uses the Soave-Redlich-Kwong (SRK) EOS for the physical part and Chapman's association term [22] as many SAFT models used for the association contribution. Remarkably, although the CPA EOS has simpler form than complex SAFT, the obtained results of some complicated associating systems are comparable to that from SAFT [34], and it has been widely adopted in the traditional and emerging field including the phase behaviors of associating fluids such as alkanols [35,36], carboxylic acids [37], amines [38], petroleum reservoir fluids [39], biodiesel [40], and drug-like molecules [41]. It is worth mentioning that there are also other CPA-type EOSs such as ESD (Elliott-Suresh-Donohue) proposed by Elliott et al [42] and the Peng-Robinson (PR) CPA EOS by Wu and Prausnitz [43].…”