Dataset for the phase equilibria and PXRD studies of urea as a green thermodynamic inhibitor of sII gas hydrates

Anton P Semenov; Yinghua Gong; Rais I Mendgaziev; Andrey S Stoporev; Vladimir A Vinokurov; Tianduo Li

doi:10.1016/j.dib.2023.109303

Dataset for the phase equilibria and PXRD studies of urea as a green thermodynamic inhibitor of sII gas hydrates

Data Brief. 2023 Jun 10:49:109303. doi: 10.1016/j.dib.2023.109303. eCollection 2023 Aug.

Authors

Anton P Semenov^{1

2}, Yinghua Gong^{1

2}, Rais I Mendgaziev², Andrey S Stoporev^{1

2

3}, Vladimir A Vinokurov^{1

2}, Tianduo Li¹

Affiliations

¹ Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, PR China.
² Gubkin University, Department of Physical and Colloid Chemistry, 65, Leninsky prospekt, Building 1, Moscow 119991, Russian Federation.
³ Department of Petroleum Engineering, Kazan Federal University, Kremlevskaya str. 18, Kazan 420008, Russian Federation.

Abstract

The equilibrium conditions of sII methane/propane hydrates have been experimentally determined for the C₃H₈/CH₄-H₂O-urea system. The equilibrium dissociation temperatures and pressures of sII hydrates span a wide P,T-range (266.7-293.9 K; 0.87-9.49 MPa) and were measured by varying the feed mass fraction of urea in solution from 0 to 50 mass%. The experimental points at feed urea concentration ≤ 40 mass% correspond to the V-L_w-H equilibrium (gas-aqueous urea solution-gas hydrate). A four-phase V-L_w-H-S_u equilibrium (with an additional phase of solid urea) was observed because the solubility limit of urea in water was reached for all points at a feed mass fraction of 50 mass% and for one point at 40 mass% (266.93 K). Gas hydrate equilibria were measured using a high-pressure rig GHA350 under isochoric conditions with rapid fluid stirring and slow ramp heating of 0.1 K/h. Each measured point represents complete dissociation of the sII hydrate. The phase equilibrium data was compared with the literature reported for the C₃H₈/CH₄-H₂O and CH₄-H₂O-urea systems. A comprehensive analysis of the thermodynamic inhibition effect of urea to sII C₃H₈/CH₄ hydrates on pressure and concentration of the inhibitor was carried out. The phase composition of the samples was analyzed by powder X-ray diffractometry at 173 K.

Keywords: Methane-propane gas mixture; Phase equilibria; Powder X-ray diffraction; Thermodynamic hydrate inhibitor; Urea; sII gas hydrates.