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Promoting Effect of Ultra-Fine Bubbles on CO2 Hydrate Formation
| Title: | Promoting Effect of Ultra-Fine Bubbles on CO2 Hydrate Formation |
| Authors: | Uchida, Tsutomu Browse this author →KAKEN DB | | Miyoshi, Hiroshi Browse this author | | Yamazaki, Kenji Browse this author | | Gohara, Kazutoshi Browse this author →KAKEN DB |
| Keywords: | nanobubble | | memory effect | | carbon dioxide | | induction time |
| Issue Date: | Jun-2021 |
| Publisher: | MDPI |
| Journal Title: | Energies |
| Volume: | 14 |
| Issue: | 12 |
| Start Page: | 3386 |
| Publisher DOI: | 10.3390/en14123386 |
| Abstract: | When gas hydrates dissociate into gas and liquid water, many gas bubbles form in the water. The large bubbles disappear after several minutes due to their buoyancy, while a large number of small bubbles (particularly sub-micron-order bubbles known as ultra-fine bubbles (UFBs)) remain in the water for a long time. In our previous studies, we demonstrated that the existence of UFBs is a major factor promoting gas hydrate formation. We then extended our research on this issue to carbon dioxide (CO2) as it forms structure-I hydrates, similar to methane and ethane hydrates explored in previous studies; however, CO2 saturated solutions present severe conditions for the survival of UFBs. The distribution measurements of CO2 UFBs revealed that their average size was larger and number density was smaller than those of other hydrocarbon UFBs. Despite these conditions, the CO2 hydrate formation tests confirmed that CO2 UFBs played important roles in the expression of the promoting effect. The analysis showed that different UFB preparation processes resulted in different promoting effects. These findings can aid in better understanding the mechanism of the promoting (or memory) effect of gas hydrate formation. |
| Rights: | © [2021] by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). |
| Type: | article |
| URI: | http://hdl.handle.net/2115/82272 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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