Pyrolysis process using a bench scale high pressure thermobalance

- Operating conditions of pyrolysis process using a HP-TGA pilot plant were studied.
- A comparison of the kinetic parameters between lab and pilot scale was carried out.
- The influence of the pressure on the pyrolysis process was evaluated.
- Evolved gases for pyrolysis process through MS were studied.
- Char obtained at different pressures was characterized.

The influence of the pressure and other operating conditions such as particle size, sweep gas flow and initial sample weight on the cellulose pyrolysis process using a bench scale plant high pressure thermobalance was evaluated. The particle size and the sweep gas flow did not have a great influence on the pyrolysis process. Nevertheless, initial sample weight altered the thermochemical behavior of the pyrolysis process. Moreover, a comparison of the values of the kinetic parameters obtained from pyrolysis experiments performed at lab and bench scale was established. On the other hand, the morphology, the presence of functional groups, the surface area, the proximate analysis and elemental analysis of the chars obtained were studied. Moreover, the evolved gases from the pyrolysis performed at different pressures were also analyzed. An increase of pressure led to both a decrease in the temperature at which pyrolysis took place and an increase in the char yield. Furthermore, the higher the pressure, the higher the porosity, the lower the pores size and the higher the occurrence of alkanes and carbonyl components in the resulting chars were. Finally, the gas released analysis from the pyrolysis process by mass spectrometry showed that high pressures promoted the CH4 and CO2 formation, the H2 yield being practically negligible.