甲缩醛合成用催化剂的中毒及再生

Poisoning and Regeneration of the Catalyst for Synthesis of Methylal

本文研究了工业甲醛原料中所含Ｆｅ３＋、Ｃｒ３＋、Ｎｉ２＋和Ｍｎ２＋四种微量金属离子对离子交换树脂型固体酸催化剂的中毒效应及其再生方法。结果表明，这些金属离子在催化剂上的吸附量随接触时间的延长而增加，而其吸附速率各不相同。催化剂对四种金属离子的吸附强度依次为Ｆｅ３＋＞Ｃｒ３＋＞Ｎｉ２＋＞Ｍｎ２＋，其中Ｎｉ２＋和Ｍｎ２＋的吸附对催化活性的影响甚微，而Ｆｅ３＋在催化剂上以较快速度吸附，其对催化活性的影响也最为明显。对因吸附金属离子而中毒的催化剂，研究了一种液相再生法，可使中毒催化剂恢复至新鲜催化剂的活性水平。

Trace metallic ions of iron,chromium,nickel and manganese in commercial grade formalin solution were determined by ICP.The influence of these impurities on poisoning of the catalyst for synthesis of methylal from formalin and methanol was investigated.It was found that the amount of the ions adsorbed in the catalyst increased with immersing time and that their adsorption rate was in the following order:Fe3+>Cr3+>Ni2+>Mn2+.The poisoning effect of nickel and manganese was negligible,while that of iron was significant.Finally,an effective method using an regeneration solution for in site regeneration of catalyst was developed.By means of the liquid phase regeneration technique,the poisoned catalyst could be reactivated to its initial activity level.