Xiaoming Li , Shiyin Feng , Yujun Guo , Chong He , Huaizhu Li , Jin Bai , Wen Li
{"title":"生物质化学循环气化中锰基氧气载体烧结过程的热力学和热力学分析","authors":"Xiaoming Li , Shiyin Feng , Yujun Guo , Chong He , Huaizhu Li , Jin Bai , Wen Li","doi":"10.1016/j.fuel.2024.132422","DOIUrl":null,"url":null,"abstract":"<div><p>The Mn-based oxygen carrier (OC) owns a great oxygen carrying capacity and a high reactivity in the chemical looping gasification of biomass. However, the sintering of the Mn-based OC can cause serious defluidization or even the shut-down of the biomass chemical looping gasifier. In this study, the sintering kinetics and mechanism of Mn-based OC in the gasification of two typical biomass ash were revealed by thermomechanical and thermodynamic analysis. It revealed that the manganese silicate was converted to iwakiite (MnFe<sub>2</sub>O<sub>4</sub>) and liquid at high temperatures in the high-Mn OC (OC2), leading to the liquid sintering mechanism and high apparent activation energy of sintering (<strong><em>E<sub>s</sub></em></strong>), with a maximum shrinkage rate of 6.14 %/<sup>o</sup>C. Conversely, the solid sintering mechanism of the low-Mn OC (OC1) was attributed to the FeMn<sub>2</sub>O<sub>4</sub> crystallization, leading to a low shrinkage rate (The maximum shrinkage rate was 0.30 %/<sup>o</sup>C). The sintering rate of Mn-based OC was closely related to the liquid content, and the biomass ash addition advantaged the liquid formation. Therefore, the <strong><em>E<sub>s</sub></em></strong> of OC1 was increased from 44 kJ/mol to 151 kJ/mol at the 15 wt% addition of corn straw ash, and <strong><em>E<sub>s</sub></em></strong> of OC2 was increased from 72 kJ/mol to 93–107 kJ/mol at 20 wt% addition of biomass ash. Element distribution analysis supported that Ca in sawdust ash improved the bonding between Mn and Si, improving the Mn-based minerals crystallization and OC expansion. However, the K in corn straw ash facilitated the melting of rhodonite(MnSiO<sub>3</sub>), and the expansion of Mn-based OC was inhibited. This study provides valuable insights into the sintering mechanism of the Mn-based oxygen carrier and its relationship with liquid evolution behavior in the chemical looping gasification of biomass.</p></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":6.7000,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Thermomechanical and thermodynamic analysis of the sintering process of Mn-based oxygen carrier in chemical looping gasification of biomass\",\"authors\":\"Xiaoming Li , Shiyin Feng , Yujun Guo , Chong He , Huaizhu Li , Jin Bai , Wen Li\",\"doi\":\"10.1016/j.fuel.2024.132422\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The Mn-based oxygen carrier (OC) owns a great oxygen carrying capacity and a high reactivity in the chemical looping gasification of biomass. However, the sintering of the Mn-based OC can cause serious defluidization or even the shut-down of the biomass chemical looping gasifier. In this study, the sintering kinetics and mechanism of Mn-based OC in the gasification of two typical biomass ash were revealed by thermomechanical and thermodynamic analysis. It revealed that the manganese silicate was converted to iwakiite (MnFe<sub>2</sub>O<sub>4</sub>) and liquid at high temperatures in the high-Mn OC (OC2), leading to the liquid sintering mechanism and high apparent activation energy of sintering (<strong><em>E<sub>s</sub></em></strong>), with a maximum shrinkage rate of 6.14 %/<sup>o</sup>C. Conversely, the solid sintering mechanism of the low-Mn OC (OC1) was attributed to the FeMn<sub>2</sub>O<sub>4</sub> crystallization, leading to a low shrinkage rate (The maximum shrinkage rate was 0.30 %/<sup>o</sup>C). The sintering rate of Mn-based OC was closely related to the liquid content, and the biomass ash addition advantaged the liquid formation. Therefore, the <strong><em>E<sub>s</sub></em></strong> of OC1 was increased from 44 kJ/mol to 151 kJ/mol at the 15 wt% addition of corn straw ash, and <strong><em>E<sub>s</sub></em></strong> of OC2 was increased from 72 kJ/mol to 93–107 kJ/mol at 20 wt% addition of biomass ash. Element distribution analysis supported that Ca in sawdust ash improved the bonding between Mn and Si, improving the Mn-based minerals crystallization and OC expansion. However, the K in corn straw ash facilitated the melting of rhodonite(MnSiO<sub>3</sub>), and the expansion of Mn-based OC was inhibited. This study provides valuable insights into the sintering mechanism of the Mn-based oxygen carrier and its relationship with liquid evolution behavior in the chemical looping gasification of biomass.</p></div>\",\"PeriodicalId\":325,\"journal\":{\"name\":\"Fuel\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":6.7000,\"publicationDate\":\"2024-07-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Fuel\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0016236124015709\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENERGY & FUELS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Fuel","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0016236124015709","RegionNum":1,"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
摘要
在生物质化学循环气化过程中,锰基氧气载体(OC)具有很强的载氧能力和高反应活性。然而,锰基氧载体的烧结会导致生物质化学循环气化炉严重脱流甚至停机。本研究通过热力学和热力学分析,揭示了锰基 OC 在两种典型生物质灰渣气化过程中的烧结动力学和机理。结果表明,在高锰 OC(OC2)中,硅酸锰在高温下转化为岩晶石(MnFe2O4)并呈液态,导致液态烧结机理和高表观烧结活化能(Es),最大收缩率为 6.14 %/oC。相反,低锰 OC(OC1)的固态烧结机理是 FeMn2O4 结晶,因此收缩率较低(最大收缩率为 0.30 %/oC)。锰基 OC 的烧结率与液体含量密切相关,而生物质灰分的添加有利于液体的形成。因此,当玉米秸秆灰的添加量为 15 wt%时,OC1 的 Es 从 44 kJ/mol 增加到 151 kJ/mol;当生物质灰的添加量为 20 wt%时,OC2 的 Es 从 72 kJ/mol 增加到 93-107 kJ/mol。元素分布分析表明,锯末灰中的 Ca 可改善 Mn 和 Si 之间的结合,从而改善 Mn 基矿物的结晶和 OC 的膨胀。然而,玉米秸秆灰中的 K 会促进菱铁矿(MnSiO3)的熔化,从而抑制锰基 OC 的膨胀。这项研究为了解锰基氧载体的烧结机理及其与生物质化学循环气化过程中液体演化行为的关系提供了宝贵的见解。
Thermomechanical and thermodynamic analysis of the sintering process of Mn-based oxygen carrier in chemical looping gasification of biomass
The Mn-based oxygen carrier (OC) owns a great oxygen carrying capacity and a high reactivity in the chemical looping gasification of biomass. However, the sintering of the Mn-based OC can cause serious defluidization or even the shut-down of the biomass chemical looping gasifier. In this study, the sintering kinetics and mechanism of Mn-based OC in the gasification of two typical biomass ash were revealed by thermomechanical and thermodynamic analysis. It revealed that the manganese silicate was converted to iwakiite (MnFe2O4) and liquid at high temperatures in the high-Mn OC (OC2), leading to the liquid sintering mechanism and high apparent activation energy of sintering (Es), with a maximum shrinkage rate of 6.14 %/oC. Conversely, the solid sintering mechanism of the low-Mn OC (OC1) was attributed to the FeMn2O4 crystallization, leading to a low shrinkage rate (The maximum shrinkage rate was 0.30 %/oC). The sintering rate of Mn-based OC was closely related to the liquid content, and the biomass ash addition advantaged the liquid formation. Therefore, the Es of OC1 was increased from 44 kJ/mol to 151 kJ/mol at the 15 wt% addition of corn straw ash, and Es of OC2 was increased from 72 kJ/mol to 93–107 kJ/mol at 20 wt% addition of biomass ash. Element distribution analysis supported that Ca in sawdust ash improved the bonding between Mn and Si, improving the Mn-based minerals crystallization and OC expansion. However, the K in corn straw ash facilitated the melting of rhodonite(MnSiO3), and the expansion of Mn-based OC was inhibited. This study provides valuable insights into the sintering mechanism of the Mn-based oxygen carrier and its relationship with liquid evolution behavior in the chemical looping gasification of biomass.
期刊介绍:
The exploration of energy sources remains a critical matter of study. For the past nine decades, fuel has consistently held the forefront in primary research efforts within the field of energy science. This area of investigation encompasses a wide range of subjects, with a particular emphasis on emerging concerns like environmental factors and pollution.