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A biological/chemical process for reduced waste and energy consumption: caprolactam production. Final report

Technical Report ·
DOI:https://doi.org/10.2172/437653· OSTI ID:437653

A biological/chemical process for converting cyclohexane into caprolactam was investigated: microorganisms in a bioreactor would be used to convert cyclohexane into caprolactone followed by chemical synthesis of caprolactam using ammonia. Four microorganisms were isolated from natural soil and water, that can utilize cyclohexane as a sole source of C and energy for growth. They were shown to have the correct metabolic intermediates and enzymes to convert cyclohexane into cyclohexanol, cyclohexanone, and caprolactone. Genetic techniques to create and select for caprolactone hydrolase negative-mutants were developed; those are used to convert cyclohexane into caprolactone but, because of the block, are unable to metabolize the caprolactone further. Because of a new nylon carpet reycle process and the long time frame for a totally new bioprocess, a limited study was done to evaluate whether a simplified bioprocess to convert cyclohexanol into cyclohexanone or caprolactone was feasible; growth rates and key enzyme levels were measured in a collection of microorganisms that metabolize cyclohexanol to determine if the bioactivity is high enough to support an economical cyclohexanol bioprocess. Although these microorganisms had sufficient bioactivity, they could tolerate only low levels (<1%) of cyclohexanol and thus are not suitable for developing a cost effective bioprocess because of the high cost of dilute product recovery.

Research Organization:
Allied-Signal, Inc., Des Plaines, IL (United States)
Sponsoring Organization:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
DOE Contract Number:
FC04-93AL94462
OSTI ID:
437653
Report Number(s):
DOE/AL/94462--2; ON: DE97000675
Country of Publication:
United States
Language:
English