摘要
借助ReaxFF-MD方法,对化学链燃烧过程Al_(2)O_(3)负载Fe_(2)O_(3)载氧体(Fe_(2)O_(3)/Al_(2)O_(3))表面CH_(4)反应过程模拟,探究Al_(2)O_(3)惰性载体对Fe_(2)O_(3)-CH_(4)体系燃烧过程的调控机制。研究发现添加Al_(2)O_(3)惰性载体改变了化学链燃烧过程中Fe_(2)O_(3)载氧体反应性和Fe_(2)O_(3)/Al_(2)O_(3)-CH_(4)反应体系的热力学和动力学行为。主要是促进了Fe_(2)O_(3)载氧体表面CH_(4)氧化,并对CH_(4)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Al_(2)O_(3)惰性载体对Fe_(2)O_(3)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Fe_(2)O_(3)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CH_(4)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。
This work simulated the reaction process of CH_(4) on the surface of Al_(2)O_(3) supported Fe_(2)O_(3) oxygen carrier(denoted as:Fe_(2)O_(3)/Al_(2)O_(3))in chemical looping combustion(CLC)by using ReaxFF-MD method,and explored the regulation mechanism of Al_(2)O_(3) inert support on the combustion process of Fe_(2)O_(3)/Al_(2)O_(3)-CH_(4) system.It was found that the addition of Al_(2)O_(3) inert carrier changed the reactivity of Fe_(2)O_(3) oxygen carrier and the thermodynamic and kinetic behaviors of Fe_(2)O_(3)/Al_(2)O_(3)-CH_(4) reaction system during CLC.The main purpose is to promote the oxidation of CH_(4) on the surface of Fe_(2)O_(3) oxygen carrier,and to significantly promote and regulate the CH_(4) reaction process,intermediates,products and their reaction rates and heat release.ReaxFF-MD simulation showed that the activation effects of Al_(2)O_(3) inert support on the lattice oxygen in Fe_(2)O_(3) 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 Fe_(2)O_(3) oxygen carriers in CLC,and favor the efficient and clean conversion of CH_(4) 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.
作者
袁妮妮
郭拓
白红存
何育荣
袁永宁
马晶晶
郭庆杰
YUAN Nini;GUO Tuo;BAI Hongcun;HE Yurong;YUAN Yongning;MA Jingjing;GUO Qingjie(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)
出处
《化工学报》
EI
CSCD
北大核心
2022年第9期4054-4061,F0004,共9页
CIESC Journal
基金
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)。
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
chemical looping combustion
Fe-based oxygen carriers
reactive molecular dynamics
alumina
computer simulation
natural gas