A 660 million lb/yr (300,000 t/yr) plant to produce hexamethylenediamine (HMDA) and caprolactam (CAPM) at 330 million lb/yr (150,000 t/yr) each is to be built, possibly in Hainan Province of China, by a Du Pont/BASF joint venture. The plant will use a new technology developed by BASF, which produces HMDA and 6-aminocapronitrile (ACPN) by partial hydrogenation of adiponitrile (ADN). The ACPN is converted to CAPM through a cyclization reaction.
This Review presents a technoeconomic evaluation of that process. Also presented are the economics of an integrated process, which combines the Du Pont/BASF process with one that makes ADN from butadiene (BD) by two-step hydrocyanation, commercially used by Du Pont. This Review also compares the economics of the two processes and two conventional processes that produce, respectively, HMDA from BD and CAPM from cyclohexane.
We conclude that the incentive to build a plant using the Du Pont/BASF process would depend on the extent of the demand for both nylon precursors. Therefore, it is less desirable to build a plant in North America, where demand for CAPM is much less than HMDA. Similarly, it is not desirable to build such a plant in Japan, where high demand for CAPM exists, but where demand for HMDA is low.
In Western Europe, both nylon 6 and nylon 6,6 are in nearly equal demand; their potential growth rates, however, are not as strong as those in Southeast Asia or China. Thus, Du Pont and BASF have determined that the two most desirable locations for the plant are China and Malaysia.
