An industrial process for the production of nylon 6 6 through the step-growth reaction of adipic acid and hexamethylenediamine

A continuous, two stage, four reactor system process is presented here for the proposed purpose of nylon 6 6 manufacture at the rate of 85 million lbs per year. Report components include: process descriptions, simulation methods and results, economic analysis, EH&S considerations, process control descriptions, and a general recommendation for how to proceed with plans enclosed. The general design of the plant is a two stage system composed of one PFR used for the formation of nylon salt and low molecular weight nylon chains, followed by three CSTR’s used for increasing nylon molecular weight. The overall process has been found to be profitable and exceeds the typical hurdle rate associated with textile production (~30%). This being said, there are considerable EH&S considerations associated with the process itself as well as the implications associated with operating a plant in Calvert City Kentucky that will need to receive due attention before a decision is made on whether to build said plant. Attributes unique to this plant include its solid feed handling system that allows the plant to use water generated solely by the polymerization reaction, during steady state operation. Additionally, the three CSTR reactors used for driving up polymer molecular weight provide exceptional process adaptability that allows for such plants to remain profitable even during economic down turns and severe market fluctuations.