Oxidation of magnesium particles in a fluidized bed reactor

IF 5.8 2区工程技术 Q2 ENERGY & FUELS

Combustion and Flame Pub Date : 2024-11-21 DOI:10.1016/j.combustflame.2024.113853

Alice Wittmann , Tomasz Wronski , Evgeny Shafirovich , Cornelius Schönnenbeck , Alain Brillard , Jean-François Brilhac , Valérie Tschamber

{"title":"Oxidation of magnesium particles in a fluidized bed reactor","authors":"Alice Wittmann , Tomasz Wronski , Evgeny Shafirovich , Cornelius Schönnenbeck , Alain Brillard , Jean-François Brilhac , Valérie Tschamber","doi":"10.1016/j.combustflame.2024.113853","DOIUrl":null,"url":null,"abstract":"<div><div>Magnesium is a promising fuel for the metal-enabled cycle of renewable energy and for space power systems. However, the existing methods for combustion of magnesium powders have difficulties with maintaining flame stability. Further, the kinetics and mechanisms of high-temperature oxidation of magnesium powders, needed for combustion modeling, are still not well understood. In the present work, a fluidized bed reactor was used to study the oxidation of spherical magnesium particles in an oxygen/helium environment at temperatures of 530, 550, and 570 °C. The extent of conversion was determined based on the measured oxygen concentration in the exhaust gas. The obtained curves of the extent of conversion and of the conversion rate were analyzed using the Avrami-Erofeev equation and the Mampel-Delmon model. The activation energy obtained with the Avrami-Erofeev equation was 191 or 198 kJ∙mol<sup>−1</sup>, depending on the dimension (3 or 2, respectively). The Mampel-Delmon approach has shown that the activation energies of nucleation and growth are equal to 189 and 120 kJ∙mol<sup>−1</sup>, respectively, i.e., the former is virtually the same as the apparent activation energy obtained with the Avrami-Erofeev model at a dimension of 3. With increasing temperature, the rate of nucleation rises faster than the rate of growth. The results obtained with the Mampel-Delmon approach help understand the oxidation mechanism, while the Avrami-Erofeev equation and the obtained apparent activation energy can be used in combustion modeling for simplicity.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"272 ","pages":"Article 113853"},"PeriodicalIF":5.8000,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Combustion and Flame","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0010218024005625","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

Magnesium is a promising fuel for the metal-enabled cycle of renewable energy and for space power systems. However, the existing methods for combustion of magnesium powders have difficulties with maintaining flame stability. Further, the kinetics and mechanisms of high-temperature oxidation of magnesium powders, needed for combustion modeling, are still not well understood. In the present work, a fluidized bed reactor was used to study the oxidation of spherical magnesium particles in an oxygen/helium environment at temperatures of 530, 550, and 570 °C. The extent of conversion was determined based on the measured oxygen concentration in the exhaust gas. The obtained curves of the extent of conversion and of the conversion rate were analyzed using the Avrami-Erofeev equation and the Mampel-Delmon model. The activation energy obtained with the Avrami-Erofeev equation was 191 or 198 kJ∙mol⁻¹, depending on the dimension (3 or 2, respectively). The Mampel-Delmon approach has shown that the activation energies of nucleation and growth are equal to 189 and 120 kJ∙mol⁻¹, respectively, i.e., the former is virtually the same as the apparent activation energy obtained with the Avrami-Erofeev model at a dimension of 3. With increasing temperature, the rate of nucleation rises faster than the rate of growth. The results obtained with the Mampel-Delmon approach help understand the oxidation mechanism, while the Avrami-Erofeev equation and the obtained apparent activation energy can be used in combustion modeling for simplicity.

查看原文本刊更多论文

流化床反应器中镁颗粒的氧化作用

镁是一种很有前途的燃料，可用于可再生能源的金属循环和太空动力系统。然而，现有的镁粉燃烧方法在保持火焰稳定性方面存在困难。此外，燃烧建模所需的镁粉高温氧化动力学和机理仍不甚明了。在本研究中，使用流化床反应器研究了球形镁颗粒在氧气/氦气环境中于 530、550 和 570 °C 温度下的氧化过程。转化程度是根据测量的废气中氧浓度确定的。利用阿夫拉米-埃罗费耶夫方程和曼佩尔-戴尔蒙模型对所获得的转化程度和转化率曲线进行了分析。阿夫拉米-埃罗费耶夫方程得出的活化能为 191 或 198 kJ∙mol-1 （取决于维数（分别为 3 或 2）。Mampel-Delmon 方法表明，成核和生长的活化能分别等于 189 kJ∙mol-1 和 120 kJ∙mol-1 ，也就是说，前者几乎与阿夫拉米-埃罗费耶夫模型在维数为 3 时得到的表观活化能相同。用 Mampel-Delmon 方法得出的结果有助于理解氧化机理，而 Avrami-Erofeev 方程和得到的表观活化能可用于燃烧建模，以简化计算。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Combustion and Flame 工程技术-工程：化工

CiteScore

9.50

自引率

20.50%

发文量

631

审稿时长

3.8 months

期刊介绍： The mission of the journal is to publish high quality work from experimental, theoretical, and computational investigations on the fundamentals of combustion phenomena and closely allied matters. While submissions in all pertinent areas are welcomed, past and recent focus of the journal has been on: Development and validation of reaction kinetics, reduction of reaction mechanisms and modeling of combustion systems, including: Conventional, alternative and surrogate fuels; Pollutants; Particulate and aerosol formation and abatement; Heterogeneous processes. Experimental, theoretical, and computational studies of laminar and turbulent combustion phenomena, including: Premixed and non-premixed flames; Ignition and extinction phenomena; Flame propagation; Flame structure; Instabilities and swirl; Flame spread; Multi-phase reactants. Advances in diagnostic and computational methods in combustion, including: Measurement and simulation of scalar and vector properties; Novel techniques; State-of-the art applications. Fundamental investigations of combustion technologies and systems, including: Internal combustion engines; Gas turbines; Small- and large-scale stationary combustion and power generation; Catalytic combustion; Combustion synthesis; Combustion under extreme conditions; New concepts.