No abstract

An atmospheric argon rf microplasma jet was employed to treat lignin samples. The treatment time was carried out from 30 min to 4 h resulting in a strong degradation of the lignin structure. The most important degradation was observed in functional groups having asymmetric in‐phase ring stretching as well as in CC and CO stretching vibrations. Simple calculations may help us explain the OH bond breakings by electron collisions inside the microplasma. In the afterglow condition, it was not observed any change on the lignin spectra.

Mass spectrometry was used to monitor neutral chemical species from sugar cane bagasse that could volatilize during the bagasse ozonation process. Lignin fragments and some radicals liberated by direct ozone reaction with the biomass structure were detected. Ozone density was monitored during the ozonation by optical absorption spectroscopy. The optical results indicated that the ozone interaction with the bagasse material was better for bagasse particle sizes less than or equal to 0.5 mm. Both techniques have shown that the best condition for the ozone diffusion in the bagasse was at 50% of its moisture content. In addition, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to analyze the lignin bond disruptions and morphology changes of the bagasse surface that occurred due to the ozonolysis reactions as well. Appropriate chemical characterization of the lignin content in bagasse before and after its ozonation was also carried out.