METHOD OF PURIFICATION OF ε-CAPROLACTAM Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes method of hydrogenating purification of ε- caprolactam from admixtures of unsaturated compounds. Mixture of caprolactam and water with caprolactam concentration from 10 to 95 wt % is first mixed with gaseous hydrogen. From 90 to 100 % of hydrogen fed is dissolved in mixture. Hydrogen containing mixture contacts with fixed bed of heterogeneous hydrogenation catalyst. Amount of hydrogen is 5.(10^-4)-10^-3 mole per mole of caprolactam. Temperature varies from 70 to 130 C and contact time varies from 10 s to 10 min. Catalyst is activated in main process zone by contacting hydrogen containing water-caprolactam mixture with hydrogenation catalyst at 70-100 C to attain more efficient of ε- caprolactam. EFFECT: more efficient purification method. 10 cl, 4 tbl