(473d) Reaction Kinetics of the Diels-Alder Cycloaddition of Dimethylfuran and Ethylene for Renewable p-Xylene

Authors: 
Green, S. K., University of Massachusetts Amherst
Williams, C. L., Idaho National Lab
Chang, C. C., University of Massachusetts Amherst
Fan, W., University of Massachusetts Amherst
Dauenhauer, P. J., University of Massachusetts Amherst



Diels-Alder cycloaddition of dimethylfuran (DMF) and ethylene to produce p-xylene is a promising method of sustainably producing valuble plastic precursors [1,2].  This step completes the entire process of (a) glucose dehydration to hydroxymethylfurfural (HMF), (b) reduction of HMF to dimethylfuran, and (c) cycloaddition/dehydration of DMF to p-xylene. The DMF/ethylene reaction proceeds via two steps: a symmetry-allowed [4+2] Diels-Alder cycloaddition of DMF and ethylene to produce an oxa-norborene cycloadduct intermediate, and subsequent dehydration of the intermediate to form p-xylene.  In this work, the kinetics of the combined cycloaddition/dehydration chemistry was experimentally evaluated, and the rate-limiting phenomena were identified. The apparent activation energy for the formation of Diels-Alder products from DMF and ethylene was experimentally measured as 17±3 kcal/mole using DMF in heptane with an H-Y catalyst in the temperature range of 200-250oC.  Research also focused on characterizing the effects of catalyst loading and determining reaction orders with respect to DMF, ethylene and p-xylene.

References

[1]  Williams, C. L.; Chang, C.-chih; Do, P.; Nikbin, N.; Caratzoulas, S.; Vlachos, D. G.; Lobo, R. F.; Fan, W.; Dauenhauer, P. J. ACS Catalysis 2012, 2, 935-939

[2] N. Nikbin, P.T. Do, S. Caratzoulas, R.F. Lobo, P.J. Dauenhauer, D.G. Vlachos, "A DFT study of the acid-catalyzed conversion of 2,5-dimethylfuran and ethylene to p-xylene," Journal of Catalysis, 2013, 297, 35-43

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