CIESC Journal ›› 2022, Vol. 73 ›› Issue (9): 4054-4061.DOI: 10.11949/0438-1157.20220686

• Energy and environmental engineering • Previous Articles     Next Articles

Reaction process of CH4 on the surface of Fe2O3/Al2O3 oxygen carrier in chemical looping combustion: ReaxFF-MD simulation

Nini YUAN(), Tuo GUO, Hongcun BAI, Yurong HE, Yongning YUAN, Jingjing MA, Qingjie GUO()   

  1. State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2022-05-12 Revised:2022-06-02 Online:2022-10-09 Published:2022-09-05
  • Contact: Qingjie GUO

化学链燃烧过程Fe2O3/Al2O3载氧体表面CH4反应:ReaxFF-MD模拟

袁妮妮(), 郭拓, 白红存, 何育荣, 袁永宁, 马晶晶, 郭庆杰()   

  1. 宁夏大学省部共建煤炭高效利用与绿色化工国家重点实验室,化学化工学院,宁夏 银川 750021
  • 通讯作者: 郭庆杰
  • 作者简介:袁妮妮(1986—),女,博士研究生,讲师,yuannini727@163.com
  • 基金资助:
    国家自然科学基金区域创新发展联合基金项目(U20A20124);国家自然科学基金项目(21868025);宁夏回族自治区重点研发计划项目(重大科技项目)(2018BCE01002);宁夏自然科学基金项目(2022A0887);宁夏高等学校一流学科建设项目(NXYLXK2017A04)

Abstract:

This work simulated the reaction process of CH4 on the surface of Al2O3 supported Fe2O3 oxygen carrier (denoted as: Fe2O3/Al2O3) in chemical looping combustion (CLC) by using ReaxFF-MD method, and explored the regulation mechanism of Al2O3 inert support on the combustion process of Fe2O3/Al2O3-CH4 system. It was found that the addition of Al2O3 inert carrier changed the reactivity of Fe2O3 oxygen carrier and the thermodynamic and kinetic behaviors of Fe2O3/Al2O3-CH4 reaction system during CLC. The main purpose is to promote the oxidation of CH4 on the surface of Fe2O3 oxygen carrier, and to significantly promote and regulate the CH4 reaction process, intermediates, products and their reaction rates and heat release. ReaxFF-MD simulation showed that the activation effects of Al2O3 inert support on the lattice oxygen in Fe2O3 active phase facilitated the migration-diffusion-release of the lattice oxygen. These findings show that the addition of inert support can enhance the lattice oxygen release of the Fe2O3 oxygen carriers in CLC, and favor the efficient and clean conversion of CH4 to the syngas, and strengthen the CLC process, as well as satisfy the goals of the current energy efficient conversion and carbon emission reduction targets.

Key words: chemical looping combustion, Fe-based oxygen carriers, reactive molecular dynamics, alumina, computer simulation, natural gas

摘要:

借助ReaxFF-MD方法,对化学链燃烧过程Al2O3负载Fe2O3载氧体(Fe2O3/Al2O3)表面CH4反应过程模拟,探究Al2O3惰性载体对Fe2O3-CH4体系燃烧过程的调控机制。研究发现添加Al2O3惰性载体改变了化学链燃烧过程中Fe2O3载氧体反应性和Fe2O3/Al2O3-CH4反应体系的热力学和动力学行为。主要是促进了Fe2O3载氧体表面CH4氧化,并对CH4反应过程、中间体、产物及其反应速率和放热量等均具有显著促进和调控作用。原因在于Al2O3惰性载体对Fe2O3活性相中晶格氧的活化作用促进了晶格氧的迁移-扩散-释放。添加惰性载体增强了Fe2O3载氧体在化学链燃烧过程晶格氧释放速率和释放量,有利于CH4氧化燃烧向合成气的高效、清洁转化,强化了化学链燃烧过程,满足当前能源高效转化和碳减排目标。

关键词: 化学链燃烧, Fe基载氧体, 反应分子动力学, 氧化铝, 计算机模拟, 天然气

CLC Number: