A Complete 1-D Model For Biomass Torrefaction Process and Results Validations Referred to an Experimantal Scale Reactor

This work presents the experimental measurements carried out on a laboratory scale torrefaction plant and the results of a one-dimensional (1-D) mass and energy torrefaction model. The experimental results of this paper derive from a campaign, performed on a fixed bed reactor, aiming at monitoring the torrefaction main parameters effects on the final product. In this work the treatment’s mass yield is assumed the guide indicator, thought which it is possible to standardize the characteristics of the final product. So, the results of the modelling analysis are compared with the experimental mass. For the modelling analysis, the reactor control volume is discretized, by using the finite elements approach in the axial direction of the tube. This 1D approach is suggested by the geometry of the reactor and it allows to perform mass and energy balances without considering the radial heat fluxes. The proposed model allows to simulate the biomasses degradation on a laboratory scale plant, working with full scale wood chips, in a completely predictable way. This investigation confirms the reliability of both the adopted kinetic & thermal model and it sets the basis for a detailed analysis of the torrefaction treatment costs.