抑制β沸石骨架脱铝的焙烧研究  

Study on Calcination Method for Preventing Removal of Structural Aluminum from β Zeolite

作　　者：孔德金[1] 邢宇[1] 陈波[1] 王辉[1] 李承烈[2] 

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院,上海201208 [2]华东理工大学,上海200037

出　　处：《Chinese Journal of Chemical Physics》2002年第2期127-131,共5页化学物理学报（英文）

摘　　要：研究了因焙烧过程升温速率对β沸石模板剂的热分解过程的影响 ,不同升温速率下Naβ沸石焙烧的尾气组成 ;还测定了Naβ沸石的TG -DTG谱 ,40 0℃下Naβ沸石的FTIR谱图 ,以及在不同温度下焙烧 4h后的XRD谱图及2 9Si、2 7Al的NMR结果 .根据这些结果 ,提出了分段焙烧脱胺方法 ,使有机胺在 2 6 0～ 42 0℃间的两个恒温段充分发生Hofmann降解反应 ,从而使分解产生的乙烯和水蒸气能够随空气流自然排出焙烧体系 ,可使焙烧过程中产生的热能得到分阶段逐步地释放 ,同时可避免高温下沸石骨架水热脱铝的负作用 ,得到骨架脱铝少、结晶度高的脱胺 β沸石 .The pyrogenic decomposition of template within zeolite Beta was greatly influenced by growth rate of calcination temperature. Inappropriate calcination methods would cause serious dealuminization from framework of β zeolite and severe reduction in β zeolite's crystallinity. Components of tail gas producing from calcination process were analyzed by chromatography. β zeolites calcined with different temperatures and as synthesized β zeolite were characterized by TG-DTG, FTIR, XRD, 29 SiNMR and 27 AlNMR. Hofmann degradation of organic amine took place chiefly at temperature range from 260℃ to 420℃. Then the oxidation of organic amine reacted mainly at temperature higher than 492℃. A stage by stage calcining method was presented by using above research results. Firstly, calcination carried at low temperature stage within range from 110℃ to 180℃ could eject water absorbed by β zeolite with air stream from the system, and hydrothermal dealuminization from framework of β zeolite that might occur at latter high temperature stage was able to be avoided. Secondly, one or two constant temperature stages placed at middle temperature range from 260℃ to 420℃ could make Hofmann degradation of organic amine react adequately, and moreover, combustible gas such as ethylene yielded from Hofmann degradation could be removed from the system and decomposition heat could be sent out stage by stage. Finally, a small quantity of residual was burned away at high temperature stage which is higher than 492℃. Temperature inside the pores of β zeolite wouldn't heighten excessively to destroy framework of β zeolite because heat energy produced from residual combusting was limited. By this method, removal of structural aluminum from β zeolite could be restrained effectively, furthermore, amine free β zeolite was able to be produced with high crystallinity.

关 键 词：Β沸石 模板剂 焙烧 脱铝 热分解 有机胺 脱胺 

分 类 号：TQ424[化学工程]