本文選題：MOCA + HY分子篩��； 參考：《浙江大學(xué)》2016年碩士論文

【摘要】：本文主要采用FCF-1L高溫高壓釜為反應(yīng)器,研究了分子篩固體酸催化鄰氯苯胺與甲醛縮合生成3,3'-二氯-4,4'-二氨基二苯甲烷(MOCA)的反應(yīng)。首先,考察了Hp (Si/Al=40)、Hβ(Si/Al=100)、HZSM-5 (Si/Al=300)和HY (Si/Al=7.5)四種硅鋁分子篩對鄰氯苯胺與甲醛縮合反應(yīng)生成MOCA的催化性能,優(yōu)選出有效合適的催化劑HY(7.5)；然后,系統(tǒng)考察了在不同反應(yīng)條件下,HY(7.5)催化合成MOCA的選擇性以及HCHO的轉(zhuǎn)化率的變化,優(yōu)化了反應(yīng)條件和工藝；進(jìn)而,基于對實驗數(shù)據(jù)的仔細(xì)分析,描述了鄰氯苯胺與甲醛在分子篩固體酸催化作用下合成MOCA以及副產(chǎn)物生成的微觀反應(yīng)機理；最后,通過催化劑的循環(huán)使用和失活再生實驗,結(jié)合新鮮和失活再生后催化劑性質(zhì)的表征,探究了催化劑的失活原因。反應(yīng)實驗數(shù)據(jù)顯示：在w(催化劑)：w(甲醛)=1：1、n(鄰氯苯胺)：n(甲醛)=8：1、反應(yīng)溫度160℃和反應(yīng)時間4h條件下,HY(7.5)分子篩催化鄰氯苯胺與甲醛縮合生成MOCA的選擇性為80.30%,HCHO的轉(zhuǎn)化率為81.7%。利用二步升溫實驗進(jìn)一步優(yōu)化反應(yīng)工藝,即反應(yīng)體系先在140℃恒溫反應(yīng)0.5h后,再升溫至160℃恒溫反應(yīng)0.5h,MOCA的選擇性為78.99%,HCHO的轉(zhuǎn)化率為85.43%。結(jié)合運用有機合成反應(yīng)化學(xué)和宏觀實驗數(shù)據(jù),詳細(xì)推測鄰氯苯胺與甲醛在分子篩固體酸催化作用下合成MOCA的微觀反應(yīng)機理主要經(jīng)歷三個步驟：首先,鄰氯苯胺與甲醛縮合生成中間產(chǎn)物N,N'-二(2-氯苯基)甲基二胺以及N-(4-氨基-3-氯芐)-2-氯苯胺；然后,N,N'-二(2-氯苯基)甲基二胺發(fā)生重排生成N-(4-氨基-3-氯芐)-2-氯苯胺和N-(2-氨基-3-氯芐)-2-氯苯胺；最后,N-(4-氨基-3-氯芐)-2-氯苯胺在B酸的催化下發(fā)生重排反應(yīng)生成MOCA。HY(7.5)分子篩的失活與再生實驗研究結(jié)果顯示：該分子篩催化劑循環(huán)使用4次后,主產(chǎn)物MOCA的選擇性從原來的78.99%降到24.15%,而反應(yīng)物HCHO的轉(zhuǎn)化率仍保持較高水平,原因可能是由于鄰氯苯胺與甲醛縮合生成中間產(chǎn)物不需要催化劑的作用也能進(jìn)行。使用4次后的HY(7.5)催化劑分別通過空氣中焙燒和苯浸洗兩種再生方法處理,其中空氣中焙燒再生后的HY(7.5)分子篩催化效果恢復(fù)明顯,使得MOCA選擇性達(dá)到79.94%,HCHO轉(zhuǎn)化率為92.19%。催化劑表面和結(jié)構(gòu)性質(zhì)表征結(jié)果顯示：失活HY(7.5)分子篩經(jīng)焙燒再生其孔容及表面積有所降低,但是其晶型結(jié)構(gòu)、酸性質(zhì)基本沒有變化,說明HY(7.5)分子篩水熱穩(wěn)定性好,可經(jīng)焙燒再生,延長循環(huán)使用時間,降低生產(chǎn)成本。
[Abstract]:In this paper, the condensation of o-chloroaniline with formaldehyde catalyzed by solid acid of molecular sieve was studied in FCF-1L reactor. First of all, the catalytic properties of four kinds of Si / Al molecular sieves, HP / Si / Al / Al 40 / H 尾 -Si / Al / HZSM-5 and HY / Si / Al 7.5) for the condensation of o-chloroaniline with formaldehyde to produce MOCA were investigated. The selectivity of MOCA synthesis and the conversion of HCHO were investigated systematically under different reaction conditions, and the reaction conditions and process were optimized. Then, based on the careful analysis of the experimental data, The microcosmic reaction mechanism of synthesizing MOCA and by-products from o-chloroaniline and formaldehyde under the catalysis of molecular sieve solid acid was described. Combined with the characterization of the catalyst properties after fresh and deactivated regeneration, the reason of deactivation of the catalyst was explored. The experimental results show that the selectivity of the condensation of o-chloroaniline with formaldehyde to MOCA is 81.7 under the reaction temperature of 160 鈩，

本文編號：1855049