ONE-DIMENSIONAL REACTOR MODEL FOR SIMULATION OF THE BIOMASS TORREFACTION PROCESS

The purpose of this work is to present the experimental measurements carried out on a small scale torrefaction plant and the preliminary results of a one-dimensional reactor model developed to simulate the process in view of setting up a scaling method to apply this procedure to model industrial torrefaction reactors. The methods adopted in this investigation are based on a preliminary experimental campaign carried out on a small scale lab-plant that consists of a vertical fixed bed reactor made of a stainless steel tube with an internal diameter of 60 mm and a length of about 1160 mm. This experimental part allows to monitor the internal thermal profile of the reactor and the influence of the main parameters such as temperature, residence time, types of feedstocks and their moisture content on the final Mass Yield of the process. The mathematical approach adopted in this study consists on a one-dimensional configuration scheme and the adopted resolution is based on a finite difference computational method. The kinetic model applied for the mass loss calculation has been developed by the same Authors and presented during this Conference. As main result this investigation confirms the reliability of the results obtained by integrating the adopted kinetic model within the computational procedure implemented to simulate the reactor. As conclusion, even if refer to a small lab-scale tests, the sensibility of the model results when applied to different values of the input variables looks promising to propose an improvement of this study both for the reactor computational scheme and the modelling of the torrefaction kinetics.