摘要
以褐煤等粉煤为原料,采用冷压成型和低温炭化工艺,研制出高热稳定性的气化用炭化型煤。在固定床气化装置中,研究了炭化型煤的水蒸气气化特性和动力学。研究表明,气化温度从880℃提高到1 000℃,碳转化率达到85%的时间从40-50min缩短至20min以内;反应进行5-8min时,炭化型煤气化反应速率达到最大值;气化温度为880℃时,反应全程处在化学反应控制区;气化温度为920℃、960℃和1 000℃时,反应过程由化学控制区向内扩散控制区转移,转移的拐点在碳转化率为90%-95%之间出现。炭化型煤气化动力学可用二维扩散模式的缩核模型描述,在化学反应控制区,表观活化能为93.83-104.11kJ/mol,表观活化能与指前因子存在动力学补偿效应;在内扩散控制区,表观活化能为76.45-87.05kJ/mol。
With lignite and other pulverized coal as raw materials,high thermal stability carbonized briquette for gasification was developed by cold press molding and low temperature carbonization.The characteristics and kinetics of the gasification reactivity with steam for carbonized briquette was investigated in fixed bed gasification reactor.The study shows that when gasification temperature increases from 880℃to 1 000℃,the reaction time of carbon conversion rate up to 85%reduces from 40-50min to 20 min or less;and the reaction rate reaches the maximum after 5-8min.The reaction process is considered in the control of the chemical reaction at 880℃;and the reaction process transfers from the chemical reaction area to internal diffusion area at 920℃,960 ℃,and 1 000℃.Besides,inflection of transfer occurs at the time of the carbon conversion rates ranging from 90% to 95%.The gasification reaction kinetic of carbonized briquette could be described by shrinking core model with two-dimensional diffusion form.The apparent activation energy ranges from 93 83kJ/mol to 104 11kJ/mol in the chemical reaction area.And the apparent activation energy,having kinetic compensation effect with pre-exponential factor,ranges from 76 45kJ/mol to 87 05kJ/mol in the internal diffusion area.
出处
《太原理工大学学报》
CAS
北大核心
2015年第3期288-293,共6页
Journal of Taiyuan University of Technology
基金
国家自然科学基金项目:型煤"球化"炭化粘结机理和收缩动力学研究(51274147)
国家科技支撑计划(2012BAA04B03)
关键词
褐煤
低温炭化
炭化型煤
水蒸气气化
反应动力学
lignite
low temperature carbonization
carbonized briquette
steam gasification
reaction kinetics
