环己酮氨肟化工艺中金属膜的工业应用研究

Industrial application of metal membrane in cyclohexanone ammoximation process

主流环己酮氨肟化工艺均使用陶瓷膜过滤器作为催化剂分离的重要设备,但陶瓷膜过滤系统在运行过程中,存在密封失效、膜管破裂,以及抗污染能力差等问题。在环己酮氨肟化装置上以金属膜替代陶瓷膜,对比研究了金属膜的过滤性能、抗污染性能,以及对双氧水与环己酮配比的影响。结果表明:使用金属膜过滤后,环己酮氨肟化反应液的浊度保持在1.20 NTU以下,浊度合格率由95.66%提升至100%;金属膜膜面流速为6.32 m/s,平均膜通量为22 t/h,比陶瓷膜分别提高82.1%、120%;金属膜跨膜压差为0.06 MPa,化学清洗频次为0.3次/月,反冲洗频次为0.08次/h,比陶瓷膜分别下降50%、70%、98%;使用金属膜后,己内酰胺耗双氧水下降3 kg/t,反应釜运行周期由100 d提升至140 d,每年可节约运行成本497万元。

The mainstream cyclohexanone ammoximation technologies all use ceramic membrane filter as an important device for catalyst separation,but the ceramic membrane filtration system has problems such as seal failure,membrane tube rupture,and poor anti-pollution performance during operation.The metal membrane was used to replace the ceramic membrane in the cyclohexanone ammoximation unit,and the filtration performance and anti-pollution performance of the metal membrane and the influence on the ratio of hydrogen peroxide and cyclohexanone were compared.The results showed that the turbidity of cyclohexanone ammoximation reaction solution was kept below 1.20 NTU after filtering with metal membrane,and the qualified rate of turbidity was increased from 95.66%to 100%;the flow velocity was 6.32 m/s on the surface of metal membrane and the average membrane flux was 22 t/h,which were 82.1%and 120%higher than those of ceramic membrane respectively;the transmembrane pressure difference of metal membrane was 0.06 MPa,the chemical cleaning frequency was 0.3 times/month,and the frequency of backwashing was 0.08 times/h,which were 50%,70%and 98%lower than those of ceramic membrane respectively;and the hydrogen peroxide consumption of caprolactam decreased by 3 kg/t,and the operation cycle of the reactor was increased from 100 d to 140 d after using metal membrane,which could save 4.97 million RMB yuan of operation cost annually.