(259e) Effect of Stirring on the Hydrate Formation Rate for Natural Gas Storage and Transportation Perspective

The liquefaction of natural gas (LNG) is an energy intensive and complex process, which requires the cooling of natural gas up to -161 ^oC. The technology required for conversion of natural gas to LNG is also sophisticated and requires large sum of investments. Therefore, the interest of academic and industrial researchers is shifting towards the use of hydrates as the mode of natural gas transportation and storage.

The process for transporting natural gas in the form of hydrates requires the conversion of natural gas into hydrate bulky crystals by cooling natural gas until the optimum temperature and then refrigerating at the suitable temperature of about -10 ^OC. This process compared to LNG seems to be simple and less energy intensive. The hydrate formation rate is the key when it comes to the conversion of natural gas to the hydrates. The mechanical factors like stirring rate or agitation of gas-water mixture can affect the conversion of natural gas into hydrates. Therefore, in this work the effect of stirring on the hydrate formation rate has been evaluated at the varying stirring rates (100-1400 RPM).

All the experimental work has been conducted using the high pressure cell that consist of a magnetic stirrer and using a gas mixture that consist of four components such as methane, ethane, carbon dioxide and nitrogen. The experimental work has been conducted at the high pressure of 98 bars and variable stirring rates (100-1400 RPM). The experimental results indicate that there exists a threshold limit above and below which no hydrate formation occurs. This shows that optimum stirring rate is necessary to facilitate the conversion of natural gas into the hydrates. This work provides a valuable insight to the researcher working in the area of natural gas storage and transportation. It is also valuable for the process engineering experts and professionals working in the area of energy transfer and storage.

Acknowledgment

This work was made possible by GSRA # 2-1-0603-14012 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.