Fe/赤泥催化水蒸气气化煤焦的反应性与微结构特性

doi:10.16085/j.issn.1000-6613.2017-1381

摘要/Abstract

摘要： 利用固定床反应器和自制Fe/赤泥（RM）、RM催化剂，进行了900℃煤焦/催化剂不同质量比的水蒸气气化实验，并采用原位红外（FTIR）、物理吸附仪（BET）、拉曼光谱（Raman）等测试手段，分析了催化气化过程中不同阶段煤焦的气化反应性、表面官能团、孔隙结构和碳微晶结构的演变规律。结果表明，Fe1/RM2催化剂可显著提高煤焦-水蒸气的气化反应性。在Fe1/RM2/煤焦-水蒸气反应过程中，煤焦表面形成—CH₂、—COOH、酚羟基等活性官能团并与Fe1/RM2活性组分相互作用，形成新的小分子基团或化合物；煤焦的比表面积先增大后减小（6.98～323.22m²/g），平均孔径呈现相反的变化趋势（2.91～11.25nm）；碳有序化程度先降低后提高，碳转化率为36%煤焦中无定形碳的相对含量最高（0.371）。在煤焦-Fe1/RM2-水蒸气反应初期（X_C<36%），煤焦表面活性基团增多、比表面积增大、有序化程度降低，综合提高了煤焦-水蒸气气化反应性；降低36%≤X_C≤62%阶段的碳有序化程度，对煤焦气化反应性的提高具有显著意义。

关键词: 煤焦, 铁/赤泥, 水蒸气气化, 催化气化, 微结构

Abstract: The coal char was gasified with steam in a fixed bed reactor at 900℃ with different mass ratio of Fe/RM catalyst. The reactivity,surface functional group,pore structure and carbon crystallite structure of char during different stages of gasification process were characterized by FT-IR,BET and Raman spectra. The results demonstrated that the steam gasification reactivity of char could be significantly improved with Fe1/RM2 catalyst. In the process of char-Fe1/RM2-steam gasification,the active functional groups,such as methylene,carboxyl and phenolic hydroxyl,formed on the surface of coal char interacted with Na⁺ and Ca²⁺ in Fe1/RM2. And thus,new small molecular active groups or compounds were formed. The specific surface area of char firstly increased and then decreased (6.98-323.22m²/g)with char conversion,while the average pore size had an opposite trend overall (2.91-11.25nm). The degree of carbon ordering was reduced first and then increased,and the relative content of amorphous carbon (0.371)was the highest when the conversion was 36%. In the initial stage of the char-Fe1/RM2 steam gasification reaction (X_C=~36%),the char gasification reactivity was improved comprehensively due to the increased surface active groups,the enlarged specific surface area and the decreased ordering degree of the char. Reducing the degree of carbon ordering ranging with the carbon conversion from 36% to 62% was significant for the improvement of char gasification reactivity.

Key words: coal char, Fe/RM, steam gasification, catalytic gasification, microstructure

中图分类号:

TQ546.1

燕希敏, 苗鹏, 常国璋, 郭庆杰. Fe/赤泥催化水蒸气气化煤焦的反应性与微结构特性[J]. 化工进展, 2018, 37(05): 1753-1759.

YAN Ximin, MIAO Peng, CHANG Guozhang, GUO Qingjie. Characteristics of microstructures and reactivities during steam gasification of coal char catalyzed by red mud[J]. Chemical Industry and Engineering Progress, 2018, 37(05): 1753-1759.

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