Mathematical Model of a Direct-Contact Pyrolysis Reactor

A mathematical model has been developed for use in assessing the performances of direct-contact pyrolysis reactors used to convert particles of raw biomass materials (usually small wood chips) into char, tar, and gas. The optimal designs are here considered to be those that maximize the production of tar. In such a reactor, the particles are injected along with a flow of a hot feed gas (usually, superheated steam), into a chamber with a heated cylindrical or conical outer wall, are blown along the wall by the flow of gas, and are held against the wall by centrifugal force. Thus, the particles are heated primarily by direct conduction from the wall. Incompletely pyrolyzed particles are collected at the outlet and reinjected at the inlet along with the hot gas and the raw feedstock.