MASS-TRANSFER AROUND CARBON PARTICLES BURNING IN FLUIDIZED-BEDS

• Type: Article in International Scientific Journal
• Date: 1991

Authors

DECARVALHO, JRFG (Author) Other; A.M.F.R. Pinto (Author) FEUP; C. Pinho (Author) FEUP

Journal

Title: Chemical Engineering Research and Design

Vol. 69

Pages: 63-70

ISSN: 0263-8762

Publisher: Institute of Chemical Engineers

Indexing

ISI Web of Knowledge - 19 Citations

Other information

Authenticus ID: P-001-R23

Abstract (EN): A study is described of combustion of coke and char particles in fluidised beds of sand and of catalyst beads. The carbon particles studied ranged in size from 1.3 to 22 mm and the beds of sand were made of closely sized particles with average diameters of 0.22, 0.32, 0.46 and 0.99 mm. The beds were operated at pressures in the range 1 to 5 bar and at a temperature of 1223 K; under those conditions carbon combustion is "diffusion controlled". The experimental data obtained clearly support the mechanism of direct carbon oxidation to CO, followed by combustion of the monoxide in the gas phase. During combustion in beds of sand the monoxide formed seems to be consumed outside the concentration boundary layer for oxygen; in beds of active catalyst combustion of CO to CO2 takes place close to the carbon surface. Mass transfer coefficients for diffusion of oxygen to burning particles are shown to be well predicted by equation (6) in the paper, which is based on the theory of Coelho and Guedes de Carvalho 7.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8