Spectroscopic and Microscopic Study of Peroxyformic Pulping of Agave Waste.
The peroxyformic process is based on the action of a carboxylic acid (mainly formic acid) and the corresponding peroxyacid. The influences of processing time (60-180 min), formic acid concentration (80-95%), temperature (60-80°C), and hydrogen peroxide concentration (2-4%) on peroxyformic pulping of agave leaves were studied by surface response methodology using a face-centered factorial design. Empirical models were obtained for the prediction of yield, κ number (KN) and pulp viscosity as functions of the aforementioned variables. Mathematical optimization enabled us to select a set of operational variables that produced the best fractionation of the material with the following results: pulp yield (26.9%), KN (3.6), and pulp viscosity (777 mL/g). Furthermore, this work allowed the description and evaluation of changes to the agave fibers during the fractionation process using different microscopic and spectroscopic techniques, and provided a comprehensive and qualitative view of the phenomena occurring in the delignification of agave fibers. The use of confocal and scanning electron microscopy provided a detailed understanding of the microstructural changes to the lignin and cellulose in the fibers throughout the process, whereas Raman spectroscopy and X-ray diffraction analysis indicated that cellulose in the pulp after treatment was mainly of type I.
['Hernández-Hernández|Hilda M|HM|', 'Chanona-Pérez|Jorge J|JJ|', 'Vega|Alberto|A|', 'Ligero|Pablo|P|', 'Farrera-Rebollo|Reynold R|RR|', 'Mendoza-Pérez|Jorge A|JA|', 'Calderón-Domínguez|Georgina|G|', 'Vera|Norma Güemes|NG|']
peroxyformic process agave fibers microscopy Raman spectroscopy