接触剂上焦炭的气化反应性能

Gasification Reactivity of Coke on Contact Materials

采用XPS、TGA-DTA、TEM-EDX、SEM-EDX技术对挂焦接触剂、气化一部分焦炭后的挂焦接触剂上的焦炭进行了物化分析。结果表明,接触剂表面的碳可以划分为无定型碳、烃类碳和羰基碳3种,并且以无定型碳为主。焦炭主要分布在接触剂颗粒表面,而且分布不均匀。接触剂颗粒体相微区内金属对焦炭的气化反应具有催化作用,金属含量越高,碳含量越少,而接触剂颗粒表面微区内金属未能体现出明显的催化气化性能。焦炭层阻碍了气化剂在金属上的吸附,接触剂上的烧焦过程或焦炭气化过程主要为非催化反应。

The coke on coked contact materials and those after partial coke gasification were studied by the methods of X-ray photoelectron spectroscopy analysis （XPS）, thermogravimetric and differential thermal analysis（TGA-DTA）, transmission electron microscopy-energy dispersive X-ray fluorescence spectrometry（TEM-EDX） and scanning electron microscopy-energy dispersive X-ray fluorescence spectrometry （SEM-EDX）. The results showed that according to different chemical environment, the carbon on contact material pellet surface could be mainly divided into three types, i. e. , amorphous, alkyl related and carbonyl related, and the amorphous carbon was considered as main type of the three in coke. A large amount of coke on pellet surface was found, which was unevenly distributed on surface. Metal elements in contact material exhibited catalysis ability to coke gasification, and the more metal content, the less carbon remained. But the metal elements existed on the pellet contact materials surface were not an apparent catalysis effect. It was speculated that coke layer on pellet surface set a barrier between gasifying agent and metal atoms, so coke burning-off or gasification was assumed to be a non-catalysis process.