Fire Safety Science Digital Archive

Three decomposition schemes for cellulose and wood are examined, the one-step engineering scheme, the three-step delinked scheme proposed by Shafizadeh and Chin and the three-step coupled scheme of Broido. The one-step scheme, though simple, can describe many behaviors observed in real problems. These include pyrolysis temperature variation with heating rate, fixed change of pyrolysis temperature with successive doubling of heating rate, and the influences of variable char yield. In addition, kinetic constants may be chosen that fit the one-step model predictions of the three-step schemes. Among the three-step schemes a strong case can be made for the superiority of the Broido scheme because it has coupled competition between the two main product pathways.