Title:
Determination of Kinetic Data for Torrefaction of Pine Bark and Maize Cane
Author(s):
Casajus, C., Marias, F., Legros-Adrian, J.M.
Document(s):
Paper
Abstract:
Torrefaction is a mild pyrolysis process with an operating temperature included in the range 220°C280°C. This technology, applied to ligno-cellulosic biomass, modifies its thermal properties and makes it stable, grindable and hydrophobic. It is then an interesting feedstock for high efficiency combustion and gasification. Because torrefaction mainly affects the hemicelluloses part of the incoming biomass, the associated reaction scheme and kinetics have been developed using this information (single step models, Di-Blasi and Lanzetta model and Koufopanos et al. model). In this study, these models have been used in order to check if they could predict the torrefaction of two residues from the agriculture and forestry industry: the pine bark and the maize cane. The investigation has been carried using two experimental devices. The first one is a “classical” TGA device (Netzsch 449C) used in the dynamic mode of operation. Using an algorithm based on the minimisation of the least square error (between experimental results and numerical predictions for both TG and DTG results) kinetic parameters were adjust for the three models quoted above. The best results were obtained with the model of. Di-Blasi and Lanzetta for both the maize caner and the pine bark. Further investigation was carried out in the isothermal mode at 220°C and 250°C. Whereas, in the dynamic mode, the numerical predictions were excellent, discrepancies between the experimental data and the model occur in the isotherm mode of operation. Hence a high capacity TGA (0.5 kg) has been set up and built in order to measure the tar and gas production associated with the torrefaction of the materials under consideration. The measure of this data provides additional information in the procedure of determining the kinetic parameters by fitting the experimental results to the numerical ones. The high capacity TGA is now completely operational. It is firstly shown that the TG obtained from the “classical” TGA and the one obtained from the high capacity are the same. Then the information gain by the estimation of the liquid and gas yield is used in order to enhance the estimation of the kinetic parameters of the model
Keywords:
biomass, reactivity, torrefaction, thermogravimetry
Topic:
Biomass Torrefaction
Subtopic:
Biomass torrefaction (session 2)
Event:
18th European Biomass Conference and Exhibition
Session:
VP2.8.2
Pages:
1552 - 1557
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-VP2.8.2
Price:
FREE
