Behaviors of CO₂ Hydrate Formation in the Presence of Acid-Dissolvable Organic Matters

Abstract

Carbon storage in the form of solid hydrate under seafloor has been considered to be promising for greenhouse gas control. Yet, open issues still remain on the role of the organic matters abundant in marine environments in the kinetics of hydrate formation; of particular interest is the involvement of the acid-dissolvable organic matters accompanying the acidification upon CO2 injection. In this work, the CO2 hydrate formation in the presence of the organic matters was in-situ monitored through the low-field nuclear magnetic resonance technique. It was found that the organic matters could kinetically promote the formation of CO2 hydrate; this effect was further enhanced by the sulfur-containing acid-dissolvable organic matters. Water in the large pores was preferentially consumed; the following water conversion facilitated by the organic matters would result in a fragmentation of the large pores into separated small pores isolated by the hydrate clusters. Consequently, a further enhancement of the gas–water contact is suggested as the existence of substantial hydrate patches could act as a mass transfer barrier. Our findings expand our understandings on the kinetics of CO2 hydrate formation in the presence of the organic matters and indicate the stability zone of gas hydrate a kinetically favorable geological setting for CO2 sequestration.

Natural Hydrophilic Amino Acids as Environment-Friendly Gas Hydrate Inhibitors for Carbon Capture and Sequestration

“…When CO 2 gas is dissolved in water, another consideration is the formation of carbonic acids that lower the pH of the aqueous phase. , One needs to consider that the solubility of the amino acids in liquid water can change with both temperature and pH under a given temperature and pressure condition. The pH of the CO 2 dissolved water at 273.15 K is estimated to be lowered to 3.18 and 4.04 with 35 bar and 1 bar of CO 2 gas, respectively, and the solubilities of amino acids (gly, l -ala, and l -val) can thus change accordingly …”

Evolution process and stabilization mechanism of different gas nanobubbles based on improved statistical analysis

“…Because of these special physicochemical characteristics, NBs can be used for a wide variety of potential industrial applications in the biology, environment, medicine, and many other fields, such as mass transfer in gas hydrate researches. [ 11–15 ]…”

“…A number of measurements [ 6,10–16 ] have shown that NBs are indeed quite stable. However, there is a lack of widespread agreement on an explanation for the stability of both interfacial and bulk NBs.…”

“…Because of these special physicochemical characteristics, NBs can be used for a wide variety of potential industrial applications in the biology, environment, medicine, and many other fields, such as mass transfer in gas hydrate researches. [11][12][13][14][15] A number of measurements [6,[10][11][12][13][14][15][16] have shown that NBs are indeed quite stable. However, there is a lack of widespread agreement on an explanation for the stability of both interfacial and bulk NBs.…”

Experimental Studies on Gas Hydrate‐Based CO2 Storage: State‐of‐the‐Art and Future Research Directions

“…In the past few years, gas hydrates have received increasing attention. [24,25] Gas hydrate technology appears to be a promising method for gas separation and storage, energy storage, and seawater desalination based on the special characteristics of hydrates. [26][27][28][29][30] Gas hydrates are ice-like crystalline compounds in which water molecules form cavities by hydrogen bonds, and gas molecules are trapped in a stable manner in these cavities by van der Waals forces.…”