TY - JOUR

T1 - Hydrate-based separation of the CO2 + H2 mixtures. Phase equilibria with isopropanol aqueous solutions and hydrogen solubility in CO2 hydrate

AU - Skiba, Sergey

AU - Chashchin, Denis

AU - Semenov, Anton

AU - Yarakhmedov, Murtazali

AU - Vinokurov, Vladimir

AU - Sagidullin, Aleksey

AU - Manakov, Andrey

AU - Stoporev, Andrey

N1 - Funding Information: This work was supported by the Russian Science Foundation (grant 20-79-00178 ). Publisher Copyright: © 2021 Hydrogen Energy Publications LLC

PY - 2021/9/21

Y1 - 2021/9/21

N2 - The gas hydrates' ability to preferentially bind one of the components of a gas mixture into a hydrate state makes it possible to consider hydrate-based technology as promising for the separation of gas mixtures. When a hydrate is obtained from a gas mixture, mixed hydrates with a complex composition inevitably occur. Issue of their composition determination stays apart. This a rather difficult task, which is complicated by the dissolution of small molecules such as hydrogen in the hydrate phase. This, in turn, impedes the analysis of the data obtained. In this work, the solubility of hydrogen in carbon dioxide hydrate in the range of 269.7–275.7 K and at partial H2 pressure up to 4.5 MPa was experimentally determined. Hydrate composition was found to be CO2·(0.01X)H2·6.5H2O at H2 pressure of X MPa. The equilibrium conditions of hydrates formation in the systems of H2O – CO2 – H2 and H2O – 2-propanol – CO2 – H2 were also determined in a wide range of hydrogen concentrations. Hydrogen seems to be an indifferent diluent gas regarding CO2 hydrate equilibrium pressure. The compositions of the equilibrium phases have been determined as well. It was shown that isopropanol does not form a double hydrate with СО2, only sI СО2 hydrate occurred in the studied systems. The obtained dependencies will be useful in analyzing the process of СО2 + Н2 gas mixtures separation by the hydrate-based method.

AB - The gas hydrates' ability to preferentially bind one of the components of a gas mixture into a hydrate state makes it possible to consider hydrate-based technology as promising for the separation of gas mixtures. When a hydrate is obtained from a gas mixture, mixed hydrates with a complex composition inevitably occur. Issue of their composition determination stays apart. This a rather difficult task, which is complicated by the dissolution of small molecules such as hydrogen in the hydrate phase. This, in turn, impedes the analysis of the data obtained. In this work, the solubility of hydrogen in carbon dioxide hydrate in the range of 269.7–275.7 K and at partial H2 pressure up to 4.5 MPa was experimentally determined. Hydrate composition was found to be CO2·(0.01X)H2·6.5H2O at H2 pressure of X MPa. The equilibrium conditions of hydrates formation in the systems of H2O – CO2 – H2 and H2O – 2-propanol – CO2 – H2 were also determined in a wide range of hydrogen concentrations. Hydrogen seems to be an indifferent diluent gas regarding CO2 hydrate equilibrium pressure. The compositions of the equilibrium phases have been determined as well. It was shown that isopropanol does not form a double hydrate with СО2, only sI СО2 hydrate occurred in the studied systems. The obtained dependencies will be useful in analyzing the process of СО2 + Н2 gas mixtures separation by the hydrate-based method.

KW - Gas hydrates

KW - Hydrogen

KW - Isopropanol

KW - Phase equilibria

KW - Solubility

KW - Thermodynamic hydrate inhibitor

UR - http://www.scopus.com/inward/record.url?scp=85112411096&partnerID=8YFLogxK

U2 - 10.1016/j.ijhydene.2021.07.112

DO - 10.1016/j.ijhydene.2021.07.112

M3 - Article

AN - SCOPUS:85112411096

VL - 46

SP - 32904

EP - 32913

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 65

ER -