Effect of fuel particle size on reaction rate in chemical looping combustion
Artikel i vetenskaplig tidskrift, 2010

Chemical looping combustion (CLC) uses an oxygen carrier circulating between an air and a fuel reactor to replace direct burning of fuels in air. The very low energy penalty for CO2 separation in CLC gives it the potential to become an important technology on the way to a CO2 neutral energy supply. In this work, the influence of the particle size of coal on the rate of reaction of the coal was investigated in a bed of oxygen carrier. In order to do this, a method to quench the reaction of coal with oxygen carriers at a specified time and measure the particle size distribution of the remaining coal was developed. Three size fractions of coal were used in the experiments: 90-125, 180-212 and 250-355 mu m. Particle size distributions of the fuel show a decrease in particle size with time. The influence of devolatilisation of the coal on the coal particle size was measured, showing that coal particles do not break in the fluidized bed reactor used for the experiments. Reaction rates based on measurements of gas phase concentrations of CO2, CO and CH4 showed that the reaction rate is independent of the particle size. These results are in line with literature findings, as studies have shown that carbon gasification is size-independent at conditions similar to those in the performed CLC experiments.

co2

Batch

Particle

system

(CLC)

coal

kinetics

Combustion

Oxygen carrier

iron-oxide

Fluidization

Chemical looping combustion

operation

solid fuels

oxygen carrier

oxidation

in-situ gasification

Författare

M. Iggland

ETH Zurich

Henrik Leion

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Tobias Mattisson

Chalmers, Energi och miljö, Energiteknik

Anders Lyngfelt

Chalmers, Energi och miljö, Energiteknik

Chemical Engineering Sciences

0009-2509 (ISSN)

Vol. 65 5841-5851

Ämneskategorier

Kemiteknik

Kemi

DOI

10.1016/j.ces.2010.08.001