A novel production route for nylon-6: Aspects of catalysis and process development

Summary: A novel production route for nylon-6 out of 6-aminocapronitrile has been investigated. Hydrolysis of 6-aminocapronitrile using a solid porous ZrO2 catalyst is the key step in this novel route. Nylon-6 with a number average molecular weight of 10 · 103 g · mol-1 can be produced from the hydrolyzed 6-aminocapronitrile. The reactor set up for the polycondensation can in broad outline be the same as the continuously operated reactor used for the -caprolactam based production of nylon-6. For the hydrolysis of 6-aminocapronitrile a number of parallel batchwise operated loop reactors is recommended. A fixed bed of catalyst particles is part of each recirculation loop. Intraparticle mass transport limitation can be avoided by using catalyst particles made of a shell of active ZrO2 and a massive inert core. An annual production of 50 · 106 kg nylon-6 demands for 5.3 m3 zirconia