Exploration on Thermal Decomposition of Cyclopentanone: A Flow Reactor Pyrolysis and Kinetic Modeling Study

Pyrolysis of cyclopentanone was investigated in a flow reactor at temperatures of 875-1428 K and pressures of 0.04 and 1 atm. Dozens of pyrolysis products including isomers, radicals, and aromatics were detected using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Among them, two groups of keto-enol tautomers were observed; one is cyclopentanone and 1-cyclopentenol, and the other one is 1,4-cyclopentadien-1-ol, 2-cyclopeten-1-one and 3-cyclopeten-1-one. A detailed kinetic model of cyclopentanone was also developed with the consideration of the theoretical progress of key reactions in this work and in the literature. Based on the experimental and simulated results, the main consumption pathways of cyclopentanone and main formation pathways of critical products were explored. Special attention has been paid to the mole fraction ratios of CO-to-fuel and ethylene-to-CO, as CO and ethylene are two of the most abundant primary decomposition products. In addition, the successive decomposition of the diradical produced from the C_β-C_γbond dissociation reaction of cyclopentanone was found to be crucial to the formation of C₃species. The recombination of these unsaturated small species also accounts for the abundant formation of 1,3-cyclopentadiene and aromatic species in cyclopentanone pyrolysis.