Silicon carbide membrane separation technology: Providing a stable and efficient catalyst separation solution for caprolactam synthesis

In the process of preparing cyclohexanone oxime (a key intermediate of caprolactam) by ammoxidation of cyclohexanone, the separation and recovery of titanium silicon molecular sieve catalysts is the core link to ensure production efficiency and product quality. Silicon carbide membrane separation technology can accurately intercept ultrafine titanium silicon molecular sieve catalysts, so that the catalyst content in the permeate is controlled below 1ppm, effectively avoiding catalyst loss, reducing production costs, and ensuring the purity of subsequent product purification. The following is a detailed explanation of its technical value based on actual cases.

Case presentation: Cyclohexanone oxime preparation catalyst separation project of a certain chemical company

(1) Process flow

Figure 1 Catalyst separation and recovery process

(2) Value analysis

Improved catalyst recovery rate: The recovery rate of titanium silicalite catalyst has increased from 85% of the traditional process to more than 99.0%, reducing the catalyst procurement cost each year;

Product purity guarantee: The catalyst residue in the permeate is ≤1ppm, avoiding impurity interference in the subsequent purification process;

Operation cost optimization: The system is fully automated and does not require special personnel on duty. In addition, the silicon carbide material is acid- and alkali-resistant and does not react with any chemical reaction with the reaction system, resulting in low annual maintenance costs.

(3) Process advantages

Outstanding chemical inertness: The silicon carbide ceramic membrane has extremely strong chemical stability and does not react with cyclohexanone, ammonia, cyclohexanone oxime and other reaction system components, eliminating product contamination from the source;

High separation accuracy: The retention rate for ultrafine titanium silicalite catalyst reaches 99.9%, and the purity of the permeate meets the requirements of subsequent processes;

Improved circulation efficiency: The catalyst is refluxed and reused in real time, reducing the frequency of adding to the reaction system and improving the production continuity rate. From efficient catalyst recovery to stable assurance of product purity, silicon carbide membrane separation technology, with its core advantages of "zero reaction interference + high-precision separation", is becoming a key support for the caprolactam synthesis process, helping the chemical industry reduce costs, increase efficiency and promote green production.