Published: September 1996
This report, supplement B to PEP Report 3, reviews the technology for producing adipic acid, one of the two precursors for the production of nylon 66. We also present the economics for the following adipic acid production routes:
- From cyclohexane via cyclohexanone and cyclohexanol (KA oil) by oxidation--the conventional process
- From benzene via cyclohexanol by partial hydrogenation and hydration--the Asahi Chemical process
- From butadiene by carboalkoxylation--a process not yet commercialized
World production of adipic acid in 1995 is estimated at 2.3 million metric tons, of which North America accounted for 42%, Western Europe 40%, Asia-Pacific 13%, and other regions 5%. At present, the industry employs three processes--a cyclohexane-based process, a benzene-based process, and a phenol-based process. Of the three, the cyclohexane-based process accounts for about 93% of production capacity, and the other two account for 4% and 3%, respectively. Cyclohexane is expected to retain its dominant position as the feedstock of choice for adipic acid manufacture in the coming decade, although our evaluations suggest that butadiene-based production via carboalkoxylation may be competitive in production cost, depending on by-product credits taken for butadiene use as fuel.
Nylon 66 is the largest outlet for adipic acid, accounting for more than 89% of total consumption in North America, 62% in Western Europe, and 56% in Japan. The remaining markets include polyurethanes, plasticizers, adiponitrile, and other uses such as polyamide-epichlorohydrin resins, polyester and alkyd resins, synthetic lubricants, and food additives.