摘要
用封闭循环式反应器考察了在K_2CO_3存在下用二氧化碳气化碳的反应,并在反应进行过程中测定了吸附于焦表面的氧量,并对焦表面吸附氧量与K_2CO_3添加量和气化反应速率的关系以及反应温度和压力对焦表面吸附氧量的影响进行了研究。结果表明,反应过程中的焦表面吸附氧量与K_2CO_3添加量成正比,气化速率随反应时间的变化与焦表面吸附氧量随时间的变化具有很好的对应关系。根据实验结果,认为在反应过程中CO_2首先在催化金属形成的活性中心被解离吸附,形成表面氧化物,气化反应速率由该表面氧化物的数量决定,并认为碳与CO_2的反应是以包括有非催化反应的表面金属氧化物的氧化还原机理进行。
Alkali catalyzed CO_2 gasification of a carbon black was studied by use of a closed recirculating reactor to clarify the catalytic mechanism.The amount of oxygen trapped by the char was measured successfully under in-situ conditions.Relationships between gasification rate,the amount of K_2CO_3 supported and the amount of oxygen trapped by the char,as well as the effect of reaction temperature and pressure on the rate were investigated carefully.It was shown that the amount of oxygen trapped by the Char during gasification was proportional to the amount of K_2CO_3 doped and the gasification rate varied with the amount of oxygen trapped during the reaction.It was concluded that during gasification,CO_2 was dissociatively adsorbed by the catalytic active sites to form surface oxides,which determines the gasification rate.Furthermore,a mechanism including a catalytic redox cycle and a noncatalytic reaction was proposed to explain the catalytic action of the alkali metal and the role of surface oxygen in carbon-CO_2 reaction.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1991年第2期156-162,共7页
Journal of Fuel Chemistry and Technology
关键词
碳
二氧化碳
IA族元素
催化
气化
catalyzed gasification
alkali metal
surface trapped oxygen
