模板法调控多级孔ZSM-5催化褐煤挥发分制备轻质芳烃的研究  

Turning hierarchical ZSM-5 by template methods and its application in catalyzing lignite-derived volatiles to light aromatics

作　　者：任雪宇 曹景沛[1] 姚乃瑜 赵小燕[1] 冯晓博 刘天龙 赵云鹏[1] REN Xueyu;CAO Jingpei;YAO Naiyu;ZHAO Xiaoyan;FENG Xiaobo;LIU Tianlong;ZHAO Yunpeng(School of Chemical Engineering&Technology,Engineering Research Center of Fine Utilization of Carbon Resources,China University of Mining&Technology,Xuzhou 221116,Jiangsu,China)

机构地区：[1]中国矿业大学化工学院,江苏省碳资源精细化利用工程研究中心,江苏徐州221116

出　　处：《化工学报》2021年第11期5620-5632,共13页CIESC Journal

基　　金：国家自然科学基金项目(22178374,21978317);江苏省自然科学基金杰出青年基金项目(BK20200028);江苏省高校优势学科建设工程资助项目。

摘　　要：在相同的水热合成条件下,以氧化炭黑为硬模板和十六烷基三甲基溴化铵(CTAB)为软模板,经一步结晶法分别制得了一系列以晶内介孔为主和以无定形介孔为主的多级孔ZSM-5分子筛。通过采用次氯酸钠、双氧水和硝酸来氧化改性商业炭黑,以增加其亲水性及分散性,进而促进了ZSM-5在晶化过程中分子筛前体与炭粒之间的相互作用。重点阐述了不同碳源和CTAB对合成的多级孔ZSM-5物化结构特性的影响,并将该催化剂用于褐煤热解挥发分催化重整制备轻质芳烃的反应中。结果表明,成功构筑的孔径均一的微-介孔梯度的ZSM-5在催化重整褐煤热解挥发分提质过程中有效地解决了催化剂的扩散传质问题,抑制了催化剂失活。引入硝酸氧化改性炭黑晶化合成的ZSM-5分子筛在褐煤热解挥发分的催化重整反应中表现出了很好的催化性能,其中轻质芳烃含量达到27.0 mg/g,选择性为81.7%。此外,在氢气气氛下,该催化剂能够有效降低积炭的碳含量。Under the same hydrothermal synthesis conditions,using oxidized carbon black as the hard template and cetyltrimethylammonium bromide(CTAB)as the soft template,a series of intracrystalline mesopores were prepared by one-step crystallization method.And the multi-porous ZSM-5 zeolite dominated by amorphous mesopores.The commercial carbon black was oxidized by sodium hypochlorite,hydrogen peroxide and nitric acid to increase its hydrophilicity and dispersion,thus promoting the interaction between ZSM-5 precursor and carbon particles in the crystallization process.The effects of different carbon sources and CTAB on the physicochemical properties of the hierarchical ZSM-5 were discussed.Meanwhile,these catalysts were used in the catalytic reforming of lignitederived volatiles to prepare light aromatics.The results show that the micro-mesoporous gradient ZSM-5 with uniform pore size can effectively solve the diffusion and mass transfer problem and inhibit the deactivation of the catalyst.ZSM-5 zeolite synthesized by oxidized carbon black with nitric acid showed good catalytic performance in the catalytic reforming of lignite-derived volatiles,in which the content of light aromatics was 27.0 mg/g and the selectivity was 81.7%.In addition,the catalyst can effectively reduce the coke content in hydrogen atmosphere.

关 键 词：多级孔ZSM-5 热解 催化活性 轻质芳烃 失活 

分 类 号：TQ530[化学工程—煤化学工程]