Gas Phase Catalytic Oxidation of Cyclohexane to Cyclohexanone and Adipic Acid

79281S In the U.S., the production of 4.6 billion pounds of Nylon-6 and Nylon-6,6 starts with the liquid-phase oxidation of 3.5 billion pounds of cyclohexane to cyclohexanone/cyclohexanol, and the subsequent oxidation of the latter to adipic acid with HNO3. The liquid-phase cyclohexane oxidation, which operates at only 4-10% cyclohexane conversion, is the ¿least efficient¿ industrial process, and wastes trillions of Btu of energy by repeatedly recycling 90-96% of the 3.5 billion pounds of cyclohexane feedstock. Just as alarming, the subsequent HNO3 process generates a billion pounds of pollutants, N2O and NOx. This project will demonstrate a gas-phase catalytic process, using only air as the oxidant, which has high potential to efficiently oxidize cyclohexane to cyclohexanone and adipic acid in one-step. At the same time, 13.5 trillion Btu of energy released from the exothermic reaction will be captured, the use of toxic/corrosive reagents will be eliminated, as will the generation and treatment of all the harmful pollutants involved in conventional liquid phase processes. Phase I will focus on the development of an effective catalyst for the efficient and selective conversion of cyclohexane to cyclohexanone and adipic acid. Catalyst development will start with the preparation of metal oxide based lead catalysts that have been proven effective for the analogous n-butane oxidation to methyl ethyl ketone, followed by compositional and structural modification guided by rational and computer-assisted designs. A catalytic testing system will be set-up and calibrated for the accurate real-time evaluation of catalysts developed and prepared for gas phase cyclohexane catalytic oxidation. Commercial Applications and Other Benefits as described by the awardee: The gas-phase catalytic oxidation of cyclohexane to selectively produce cyclohexanone and adipic acid in one-step should replace the current conventional processes for cyclohexanone and adipic acid production via liquid-phase cyclohexane oxidation followed by oxidation with HNO3. The major benefits will be (1) economic ¿ by replacing the ¿least efficient¿ liquid-phase process with a efficient gas-phase process; (2) enery savings ¿ by capturing more than 13.5 trillion Btu per year of energy gained from the exothermic high temperature gas-phase process; (3) safety ¿ by eliminating the use, consumption, and recycling of a billion pounds of toxic and corrosive reagents including HNO3 and boric acid; and (4) environmental ¿ by eliminating the generation of a billion pounds of harmful air pollutants, such as N2O and NOx.