金属盐催化剂对木粉半焦CO2气化反应性的影响

EFFECTS OF METAL-SALT CATALYSTS ON CO_2 GASIFICATION REACTIVITY OF FIR CHAR

在热重分析仪上进行了几种金属盐(K、Na、Ca、Mg、Fe)对杉木粉半焦CO_2催化气化反应特性的研究;利用XRD和SEM技术对半焦样品的碳化程度、晶相结构及表面形貌进行了表征。研究表明:5种金属盐均提高了半焦样品的反应活性;且反应活性指标显示其催化效果顺序为K>Na>Ca>Fe>Mg。XRD结果显示:Na和Ca在制焦过程中形成了明显的晶相结构;Mg增强了半焦中碳的有序化程度。SEM结果表明:5种金属盐均在半焦表面形成了"斑点"状的活化中心点且在碱金属半焦的部分表面观测到疏松片状结构。

The effects of five metal-salt catalysts （K, Na, Ca, Mg and Fe） on CO2 gasification reactivity of fir char were studied using a thermal gravimetric analyzer. The carbonization degree, crystal structure and morphology of char samples were characterized by X-ray diffractometry （XRD） and scanning electron microscopy（SEM）. Results showed that the CO2 gasification reactivity of fir char is improved through the addition of metal-salt catalysts, and the effects of the five catalysts on it were in the sequence of K 〉 Na 〉 Ca 〉 Fe 〉 Mg. XRD analysis indicated that Na and Ca were easier to form crystal structure compared with other metals, and that Mg enhanced the degree of carbon structure ordering. SEM analysis showed that spotted activation center distributed on the surface of char samples impregnated with catalysts. Moreover, loose flake structure is observed on the surfaces of both K-Char and Na-Char.