A new kinetic model for non-isothermal pyrolysis of MDF (medium-density fiberboard) derived Beech sawdust monitored by STA-MS analysis: The influence of experimental parameters on process characteristics

Abstract

A novel kinetic model for pyrolysis of MDF (medium-density fiberboard) derived Beech sawdust was proposed. The complete procedure includes a combined four parallel reaction model (CPRM) and three-component Log-Normal distributed reactivity model. Based on the matrix analysis, it was found that for quality pyrolysis performing, the lower values of the heating rates (where the possibility of the secondary reactions is significantly reduced) are highly desirable. CPRM approach showed that with an increase of heating rate, pyrolysis rate of UF-resin adhesive rapidly increases and its rate curve moves very close to decomposition curve related to cellulose. At the highest heating rate, the UF-resin adhesive pyrolysis curve "overrated" cellulose-related curve. It was assumed that UF-resin adhesive participates in cellulose decomposition, hastening chemical bonds breaking in cellulose molecule, and further stimulating lignin decomposition. Three-component Log- Normal distributed reactivity model showed that certain asymmetries in effective activation energy distribution curves for some pseudocomponents is a consequence of a wider variety of bonds present, and/or "capacity" in the tendency of an easier bond breaking. Both approaches, contained in the newly proposed model, confirm the strong deviation from the additive behavior (the adhesive compound present in the studied lignocellulose material does not produce the synergistic effect).