Partial and complete methane oxidation in supercritical water
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- 作者：A. A. Vostrikov ; O. N. Fedyaeva ; A. V. Shishkin…
- 刊名：Journal of Engineering Thermophysics
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：25
- 期：4
- 页码：474-484
- 全文大小：1,099 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Thermodynamics
Gases
Russian Library of Science - 出版者：MAIK Nauka/Interperiodica distributed exclusively by Springer Science+Business Media LLC.
- ISSN：1990-5432
- 卷排序：25
文摘
The paper represents results on investigation of methane oxidation in supercritical water (SCW) in autoclave and flow conditions. In the autoclave, oxidation is realized under uniform heating of a CH4/O2/H2O and CH4/O2/N2 mixture to 873 K (the water and nitrogen density ≈ 3.2 mmol/cm3, the molar ratio [O2]0/[CH4]0 ≈ 1 and 2). In the composition of the oxidation products we detected H2 (only at [O2]0/[CH4]0 ≈ 1), CO and CO2. Based on time dependences of the reaction mixture temperature we have found that temperature of the onset of self-heating of the CH4/O2/H2O mixture is lower by 23 K than that of the CH4/O2/N2 mixture and grows as the CH4 concentration decreases. For comparable values of self-heating the average power in CH4 combustion in the H2O medium has appeared to be about two orders lower than in the N2 medium, which evidences inhibition of SCWmethane oxidation. In the boiler-reactor, oxidation was realized while mixing CH4 and O2 in counter-propagating jets in the cocurrent upflow of SCW at 673–874 K, 30 MPa (molar ratio [O2]/[CH4] ≈ 2.2). Unsteady combustion was observed only at a reaction mixture temperature of 678 K, which became steady at 700 K after a series of flashes. The carbon-bearing methane oxidation products in the boiler-reactor contain only CO2 (≥ 97.5%) and CO (≤ 2.5%mole).