Selective Production of 4-Vinylphenol by Fast Pyrolysis of Herbaceous Biomass

4-Vinylphenol is an important chemical that can be used as the monomer for the production of poly(4-vinylphenol) (PVPh). Currently, 4-vinylphenol was prepared by the dehydrogenation of 4-ethylphenol over chromia/alumina catalyst at 600 degrees C. In this study, a low-cost process involving low-temperature fast pyrolysis of biomass without any catalyst was developed to selectively produce 4-vinylphenol. Pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) was used for the fast pyrolysis of bagasse, cornstalk, bamboo, rice husk, rice straw, cotton straw, and poplar wood to investigate the effects of different materials on the selectivity of 4-vinylphenol. It was found that some of the herbaceous materials, such as bagasse, cornstalk, and bamboo, were suitable for the production of 4-vinylphenol, whereas woody materials were not applicable. The effects of temperature on 4-vinylphenol production were also investigated. 4-Vinylphenol contents of up to 7 and 20 wt % were achieved at 300 degrees C from bagasse and bagasse EMAL, respectively. For the first time, 4-vinylphenol was separated from the pyrolysis oil obtained by the fast pyrolysis of bagasse using a benchtop unit, and its structure was confirmed by various methods. Additionally, it was verified that 4-vinylphenol could be produced from compounds with a beta-5 linkage, and a possible mechanism for the generation of 4-vinylphenol from a lignin model compound with a beta-5 linkage is proposed.