RT Journal Article
T1 Pyrolysis of biofuels of the future: Sewage sludge and microalgae-Thermogravimetric analysis and modelling of the pyrolysis under different temperature conditions
A1 Soria Verdugo, Antonio
A1 Goos, Elke
A1 Morato Godino, Andrés
A1 García Hernando, Néstor
A1 Riedel, Uwe
AB The pyrolysis process of both microalgae and sewage sludge was investigated separately, by means of non-isothermal thermogravimetric analysis. The Distributed Activation Energy Model (DAEM) was employed to obtain the pyrolysis kinetic parameters of the samples, i.e. the activation energy Ea and the pre-exponential factor k0. Nine different pyrolysis tests at different constant heating rates were conducted for each sample in a thermogravimetric analyzer (TGA) to obtain accurate values of the pyrolysis kinetic parameters when applying DAEM. The accurate values of the activation energy and the pre-exponential factor that characterize the pyrolysis reaction of Chlorella vulgaris and sewage sludge were reported, together with their associated uncertainties. The activation energy and pre-exponential factor for the C. vulgaris vary between 150–250 kJ/mol and 1010–1015 s−1 respectively, whereas values ranging from 200 to 400 kJ/mol were obtained for the sewage sludge activation energy, and from 1015 to 1025 s−1 for its pre-exponential factor. These values of Ea and k0 were employed to estimate the evolution of the reacted fraction with temperature during the pyrolysis of the samples under exponential and parabolic temperature increases, more typical for the pyrolysis reaction of fuel particles in industrial reactors. The estimations of the relation between the reacted fraction and the temperature for exponential and parabolic temperature increases were found to be in good agreement with the experimental values measured in the TGA for both the microalgae and the sludge samples. Therefore, the values reported in this work for the activation energy and the pre-exponential factor of the C. vulgaris can be employed as reference values in numerical studies of the pyrolysis process of this biofuel since its chemical composition is quite homogeneous. In the case of sewage sludge, due to the heterogeneity of its composition, the results reported for the kinetic parameters of the pyrolysis process can be employed to describe the pyrolysis of sludge with similar composition.
PB Elsevier
SN 0196-8904
YR 2017
FD 2017-04-15
LK https://hdl.handle.net/10016/32566
UL https://hdl.handle.net/10016/32566
LA eng
NO The authors express their gratitude to the BIOLAB experimental facility and to the “Programa de movilidad de investigadores en centros de investigación extranjeros (Modalidad A)” from the Carlos III University of Madrid (Spain) for the financial support conceded to Antonio Soria for a research stay at the German Aerospace Center DLR (Stuttgart, Germany) during the summer of 2016. The authors also gratefully acknowledge the financial support provided by Fundación Iberdrola under the “VI Programa de Ayudas a la Investigación en Energía y Medioambiente”. Funding by the energy, combustion, and gas turbine technology program (EVG) of Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), the German Aerospace Center, is gratefully acknowledged as well as funding by the DLR international collaboration project “Accurate Kinetic Data of Biomass Pyrolysis”
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RD 27 jul. 2024