粉煤灰活化及其制备多孔催化材料的研究进展  

Research progress of fly ash activation and its application in the porous catalytic materials

作　　者：陆强[1] 吴亚昌 徐明新 刘子树 张平新 欧阳昊东 LU Qiang;WU Yachang;XU Mingxin;LIU Zishu;ZHANG Pingxin;OUYANG Haodong(National Engineering Laboratory for Biomass Power Generation Equipment,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学生物质发电成套设备国家工程实验室,北京102206

出　　处：《洁净煤技术》2021年第3期1-12,共12页Clean Coal Technology

基　　金：国家自然科学基金资助项目(51806220,51922040);中国博士后科学基金资助项目(2019M660594);中央高校基本业务费资助项目(2020DF01)。

摘　　要：粉煤灰是煤燃烧过程产生的重要固体废弃物,产量巨大,其排放不仅占用了大量土地资源,还引发了一系列环境问题。目前,粉煤灰的资源化利用方式主要为建筑材料,附加值较低。粉煤灰中SiO_(2)、Al_(2)O_(3)总量超过80%,以粉煤灰制备多孔催化材料可实现粉煤灰的高附加值资源化利用。但由于原始粉煤灰的热稳定性高、成型性差,需要对其进行改性处理。介绍了粉煤灰的基本理化特性,包括粉煤灰的化学组成、晶相结构、粒径分布等。并对目前粉煤灰的改性方式进行分析,包括粉煤灰直接做载体和分子筛,其中酸改性、碱改性和等离子体改性是常用的粉煤灰直接做载体的改性方式;一步水热法、两步水热法、碱熔融-水热法和微波辅助法是常用的粉煤灰基分子筛合成方法。此外,对粉煤灰基催化剂的应用领域进行了概述,包括有机降解、有机合成和无机污染物脱除等,其中有机降解主要包含光催化反应和非光催化反应,有机合成主要包括缩聚反应和酯化反应,无机污染物脱除主要包括氮氧化物处理和汞催化氧化。目前粉煤灰做多孔催化材料有较大发展潜力,但常规改性方式各有利弊,技术还不够成熟,需进一步完善;不同反应体系对粉煤灰载体性质要求不一,改性方式应贴合催化反应需求。最后对目前粉煤灰制备多孔催化材料的发展做出展望,可对后续粉煤灰高值化利用以及粉煤灰基催化剂的相关研究提供支撑。Fly ash is a momentous industrial solid waste produced in the process of coal combustion,with huge output.The storage of fly ash not only occupies the pile lands,but also causes a series of environmental problems.Currently,fly ash is mainly utilized as the construction materials in China,which has low economic value.The total amount of SiO_(2) and Al_(2)O_(3) in fly ash is more than 80%.The preparation of porous catalytic materials from fly ash can realize the resource utilization of high added value of fly ash.However,due to the high thermal stability and poor moldability of the original fly ash,the original fly ash needs to be modified.In this review,the fundamental physical and chemical properties of fly ash were introduced firstly,including the elemental composition,crystal phase structure and particle size distribution.Then,the current modification methods of fly ash were described in detail,including the preparation of catalyst carriers and molecular sieves.Acid modification,alkali modification and plasma modification methods are frequently used in the process of original fly ash direct modification to obtain catalyst carriers.One-step hydrothermal,two-step hydrothermal,alkali fusion-hydrothermal and microwave-assisted hydrothermal are generally used for the preparation of molecular sieves from fly ash.Besides,the application fields of fly ash-based catalysts were briefly introduced,consisting of organic degradation,organic synthesis and inorganic gaseous pollutants removal.Organic degradation mainly includes photocatalytic and non-photocatalytic reactions,and organic synthesis mainly includes catalytic polycondensation and esterification.The inorganic gaseous pollutant removal is mainly about denitration and mercury catalytic oxidation.It is found that fly ash exhibits good developing potential as catalyst carrier materials.However,the conventional modification methods have their own advantages and disadvantages,and the technology is still not mature enough,and some further research is needed.Besides,the m

关 键 词：粉煤灰 活化 多孔催化材料 载体 改性 分子筛 

分 类 号：TQ426.6[化学工程]