Hsuan-Chih Wu, Young Ku 


Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan



Received: August 18, 2018
Revised: April 28, 2019
Accepted: June 19, 2019
Download Citation: ||https://doi.org/10.4209/aaqr.2018.06.0222 

  • Download: PDF


Cite this article:
Wu, H.C. and Ku, Y. (2019). Evaluation of Iron-based Oxygen Carrier Supported on Alumina/Titania for Charcoal Combustion through Chemical Looping Process. Aerosol Air Qual. Res. 19: 1920-1936. https://doi.org/10.4209/aaqr.2018.06.0222


HIGHLIGHTS

  • Fe2O3/Al2O3/TiO2 and Fe2O3/Al2O3 particles provided with high reactivity for CO/H2.
  • Higher mass transfer coefficient was observed for Fe2O3/Al2O3/TiO2 reduction.
  • Over 47% of maximum carbon conversions were reached for charcoal combustion in MBR.
  • Less oxygen carriers are required for charcoal combustion with Fe2O3/Al2O3/TiO2.
  • Roughly 255W was released for CLC of charcoal with Fe2O3/Al2O3/TiO2.

ABSTRACT


Hematite supported on alumina or alumina/titania was fabricated to serve as an oxygen carrier in the chemical looping combustion (CLC) of charcoal. The reduction rate of Fe2O3/Al2O3 and Fe2O3/Al2O3/TiO2 particles increased with the reactor inlet’s CO concentration and displayed a slight effect from elevated operating temperatures. Applying the shrinking core model, the mass transfer coefficients (kg) for the reduction of Fe2O3/Al2O3 and Fe2O3/Al2O3/TiO2 by CO were found to be 0.16 and 0.22 mm s–1, respectively, and using the Fe2O3/Al2O3 and Fe2O3/Al2O3/TiO2 to combust charcoal resulted in carbon conversion rates of approximately 61.8% and 47.2%, respectively, when the inlet steam flow rate was set to 221.4 mmol min–1. Significantly, a higher inlet steam flow rate may not be advantageous when employing iron-based oxygen carriers. More heat was released during combustion with the Fe2O3/Al2O3 than with the Fe2O3/Al2O3/TiO2 due to a high flow rate for the former being used. When Fe2O3/Al2O3/TiO2 was used as the oxygen carrier, the particles, which contained a large percentage of Fe2O3, exhibited high reactivity to syngas (CO/H2); thus, less Fe2O3/Al2O3/TiO2 than Fe2O3/Al2O3 was required to combust the charcoal.


Keywords: Chemical looping process; Charcoal combustion; Hematite; Reduction kinetic; Moving bed reactor.

 



Impact Factor: 2.735

5-Year Impact Factor: 2.827


SCImago Journal & Country Rank

Enter your email below to receive latest published articles in your field.