Intrinsic kinetics of isothermal xylan degradation in inert atmosphere

摘要: Thermal degradation of thin layers milled, commercial xylan is made to occur under controlled sample temperature, by proper variation in the intensity applied radiative heat flux. The process consists fast heating (40–70 K s−1) desired which then maintained until complete conversion. A continuous helium flow avoids extra-particle secondary reactions primary volatile products and establishes an inert reaction environment. Time-weight loss curves are determined for temperatures range 473–613 K, where ratio between conversion times very large (1000-100) weight during period small (0–16%). isothermal well interpreted a two-stage mechanism. first, stage takes into account competitive formation volatiles solid intermediate. second, slow place above 523 describes char from kinetic data two stages are: A1 = 3.62 × 105 s−1, E1 18.3 kcal mol−1 A2 3.83 102 E2 13.1 mol−1. final yields vary with temperature 68 10%, most released course first stage.