Speculative Incremental Design Improvement for Caprolactam Via Liquid Phase Ammoximation And Vapor Phase Rearrangement

This review is the continuation of a series of reviews studying the Enichem-Sumitomo joint venture to combine their respective technologies. PEP Report 7C first examined the Enichem liquid phase ammoximation technology, while PEP Review 1998-15 initiated the evaluation of the Sumitomo vapor phase rearrangement technology. Physical property limitations in the simulation databanks spawned several follow-up reviews (PEP Reviews 2001-2, 2004-1, and 2004-6) to address the gaps and provide the missing parameters. PEP Review 2004-7 updated the results from the previous evaluations once all the property parameters were estimated, finally addressing the economic feasibility of one possible combination of the joint venture technologies. That review concluded that the technology was infeasible, but that a number of design improvements were possible.

In this review, additional physical property issues required still further approximation and parameter estimation, highlighting the speculative nature of these evaluations. However, if the liquid-liquid split in caprolactam refining behaves as the patents imply, massive capital cost reductions and some operating cost improvements could result. If valid, the process alteration appears to be more economical than competing technologies. Unfortunately, estimated market prices for caprolactam suggest that no process is truly economical. Several variables are noted as possible areas of economic improvement, but those concepts would need to be demonstrated in additional patents or published literature before such designs could be considered. The results shown in this review are also speculative, given the limited accuracy of property assumptions required to complete the design..