Solar Biomass Pyrolysis with Latent Heat Ballast

HUILI, ZHANG; JAN, BAEYENS; RAF, DEWIL; SHUO, LI; YIMIN, DENG; ANDRÉS, REYES-URRUTIA; VENIER, CÉSAR; GERMÁN, MAZZA

2021 5th International Conference on Power and Energy Engineering, ICPEE 2021

Institute of Electrical and Electronics Engineers Inc.

Año: 2021 p. 85 - 90

The concentrated solar-driven pyrolysis of biomass (sawdust) was examined in a fluidized bed reactor with 0.15 mI.D. and 0.3 m bed height, using cristobalite sand as bed material. The fluidized bed a reactor was fitted with in-bed tubes, filled with a phase change material with phase change temperature of 450 to 475°C. Four, 5 and 9 tube-inserts were examined. The solution with 5 tube-insert was experimentally demonstrated to considerably influence the bubble sizes and frequencies in the reactor, leading to an enhanced heat transfer from the irradiated reactor wall to the fluidized bed, and from the fluidized bed to the in-bed tubes. The steam assisted pyrolysis produced between 40 and 55 wt% of high-quality biochar (BET > > 100 m2/g), about 20 to 25 wt% of oxygenated bio-oil and the balance as syngas. The operation at moderate temperature and with steam injection drives the pyrolysis reactor towards biochar production. In using the PCM-ballasted inserts, the temperature could be narrowly controlled within the selected operation range, whereas it was also possible to maintain the temperature at the required level for 15 to 20 minutes during non-sun periods.