双氧水生产中钯催化剂的使用若干问题的探讨

Discussion on problems about palladium catalyst used in production of hydrogen peroxide

阐述了双氧水生产中钯催化剂使用中存在的几个重要问题,并提出改进措施。对双氧水生产中钯催化剂使用温度进行了探讨。通过建立氢化反应温度和氧化铝再生温度之间的关联和良性互动,即氧化铝再生温度随着氢化温度的升高而升高,从而提高氧化铝对降解物的再生效果,可以使钯催化剂运行温度较过去提高10℃以上。通过观察分析发现,停车前停氢不补氮气运行,导致固定床底压比顶压高出很多,底部封存的气体快速上升,冲击上层瓷球,是引起催化剂床瓷球下翻的重要原因,并提出改进措施。提出新催化剂和再生后的催化剂使用前不活化更好,再生的水流量对再生效果有较大影响,最好要达到工作液流量的20%～30%,才能有效清除污物。

Major problems about palladium catalyst used in production of hydrogen peroxide were expounded and improvement measures were put forward. Palladium catalyst temperature used in production of hydrogen peroxide was discussed and running temperature of palladium catalyst can be raised above 10 ℃ higher than before by establishing the link and positive interaction between hydrogenation reaction temperature and alumina regeneration temperature, that is,alumina regeneration temperature increases along with the lifting of hydrogenated temperature,thereby the regeneration effect of alumina to degradation products is enhanced. An important reason why the upper ceramic balls in catalyst bed turn down was found by observing, that is, nitrogen has not been added when stop hydrogen before unit stops running, that causes bottom pressure much higher than top＇s,therefore,the gas closed in bottom of the fixed bed rises rapidly,impacts the upper ceramic ball, leads to its turn down. Then, improvement measures were put forward. It is better that a new catalyst and the one after regenerated are not activated before used, and the water flow used in regenerating have a greater impact on regeneration effect. In order to remove the dirt effectively,the best water flow is to reach 20% - 30% of the working solution flow.