Chemically Influenced Self-Preservation Kinetics of CH<sub>4</sub> Hydrates below the Sub-Zero Temperature

oleh: Jyoti Shanker Pandey, Saad Khan, Nicolas von Solms

Format: Article
Diterbitkan: MDPI AG 2021-10-01

Deskripsi

The self-preservation property of CH<sub>4</sub> hydrates is beneficial for the transportation and storage of natural gas in the form of gas hydrates. Few studies have been conducted on the effects of chemicals (kinetic and thermodynamic promoters) on the self-preservation properties of CH<sub>4</sub> hydrates, and most of the available literature is limited to pure water. The novelty of this work is that we have studied and compared the kinetics of CH<sub>4</sub> hydrate formation in the presence of amino acids (hydrophobic and hydrophilic) when the temperature dropped below 0 °C. Furthermore, we also investigated the self-preservation of CH<sub>4</sub> hydrate in the presence of amino acids. The main results are: (1) At T < 0 ℃, the formation kinetics and the total gas uptake improved in the presence of histidine (hydrophilic) at concentrations greater than 3000 ppm, but no significant change was observed for methionine (hydrophobic), confirming the improvement in the formation kinetics (for hydrophilic amino acids) due to increased subcooling; (2) At T = −2 °C, the presence of amino acids improved the metastability of CH<sub>4</sub> hydrate. Increasing the concentration from 3000 to 20,000 ppm enhanced the metastability of CH<sub>4</sub> hydrate; (3) Metastability was stronger in the presence of methionine compared to histidine; (4) This study provides experimental evidence for the use of amino acids as CH<sub>4</sub> hydrate stabilizers for the storage and transportation of natural gas due to faster formation kinetics, no foam during dissociation, and stronger self-preservation.