22nd International Symposium on Analytical and Applied Pyrolysis
Kyoto, 2018
A NEW LASER FAST PYROLYSIS DEVICE WITH IMAGING OF PARTICLES
AND ON-LINE ANALYSIS OF VOLATILES
A. Dufoura*, S. Beckerb, H. Le Galla, M. Weberb, O. Dufauda, Y. Le Brecha, G. Mauviela, G. Parentb
a LRGP,
b LEMTA,
CNRS, Université de Lorraine, ENSIC, Nancy, France
CNRS, Université de Lorraine, Vandoeuvre les Nancy, France
* anthony.dufour@univ-lorraine.fr
In this poster, we will present a novel device developed at CNRS Nancy to study the fast pyrolysis of various solid fuels
under well controlled thermal conditions. Indeed, the real temperature of particles during their fast pyrolysis remains
unknown due to the lack of real-time imaging of the temperature during the reaction. Most of the fast pyrolysis microreactors present huge thermal lags of several dozens of degrees [1-2]. Indeed the true heating rate and temperature of
reacting particles can be different than the heating rate and temperatures of the heating source [3,4]. Furthermore the
temperature given by thin thermocouples may not be accurate under fast conditions (thermal lag between the reacting
particles and the thermocouple).
For all these reasons, we have developed a novel laser-pyrolysis device in Nancy. Its concept is presented below.
Thermal imaging of real
temperature of particles
during pyrolysis
On-line mass
spectrometry
Visible fast imaging
of the shape of
particles
Material to be
pyrolysed deposited
over a silica lamella
Heating by
CO2 laser
The set-up is composed of:
- a high power (180W) CO2 laser (emitting an IR light at 10.6µm);
- thin film of solids are deposited over a silica lamella;
- the laser heats the silica lamella and the temperature heating program of this support is controlled by an
advanced monitoring system based on the analysis of temperature with a pyrometer;
- the real-time temperature of particles undergoing pyrolysis is measured by a multiband IR camera;
- the shape of particles (bubbles formation, aerosols ejection) is analyzed by a fast visible camera;
- the composition of volatiles is analyzed on-line by laser-photoionisation mass spectrometry [5].
In this poster, we will show how this set-up is able to study the pyrolysis of various solids (biomass, synthetic polymers,
etc.) by assessing simultaneously the evolution of the (true) temperature and shape of particles and the composition of
volatiles. We will notably depict how “fast pyrolysis conditions” can be misled if the real temperature of pyrolysis is not
accurately measured.
[1] Bahng, M.-K., Donohoe, B.S., Nimlos, M.R., Energy Fuels, 25 (1), pp. 370-378, 2011.
[2] Prins, M.J., Lindén, J., Li, Z.S., (...), Aldén, M., Goey, L.P.H.D. Energy Fuels 23 (2), pp. 993-1006, 2009.
[3] Lédé, J., Authier, O. Journal of Analytical and Applied Pyrolysis, 113, pp. 1-14, 2015.
[4] Lédé, J. Energies 3(4), pp. 886-898, 2010.
[5] Jia et al., Energy Fuels, 2016, 30 (3), pp 1555–1563