Oxidation of a coal particle in flow of a supercritical aqueous fluid

Journal Article · Sat Mar 15 04:00:00 EDT 2008 · Combustion, Explosion and Shock Waves (English Translation)

DOI:https://doi.org/10.1007/s10573-008-0020-2· OSTI ID:21049864

Vostrikov, A A; Dubov, D Y; Psarov, S A; Sokol, M Y ^[1]

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1. Russian Academy of Sciences, Novosibirsk (Russian Federation). Kutateladze Instititue for Thermophysics

A study was made of the conversion of single spherical coal particles of diameter 1-5 mm in a supercritical H{sub 2}O/O{sub 2} fluid with an oxygen mass fraction of 0-6.6% in a semibatch reactor at a pressure of 30 MPa and a temperature of 673-1023 K. A decrease in the particle mass was observed in two parallel processes: gasification of coal with water and oxidation of coal with oxygen. An activation energy 19 {+-} 7 kJ/mole and a pre-exponential factor 10{sup -2}{+-} 0.4 sec{sup -1} were obtained under the assumption of zero order for the concentration H{sub 2}O and an Arrhenius dependence for the rate of gasification with water. The oxidation with oxygen at a temperature above 780 K was found to be limited by the rate of O{sub 2} diffusion to the coal organic matter. Below 780 K, the rate of heterogeneous oxidation with oxygen is described by a first-order reaction for the concentration of O{sub 2} and a zero-order reaction for the concentration of H{sub 2}O with an activation energy of 150 {+-} 27 kJ/mole and a pre-exponential factor of 10{sup 7.6}{+-} 1.9 cm{sup 3}/(g . sec).

• OSTI ID: 21049864
• Journal Information: Combustion, Explosion and Shock Waves (English Translation), Journal Name: Combustion, Explosion and Shock Waves (English Translation) Journal Issue: 2 Vol. 44; ISSN CESWA4; ISSN 0010-5082
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ACTIVATION ENERGY
ARRHENIUS EQUATION
CHEMICAL REACTION KINETICS
COAL
COAL GASIFICATION
OXIDATION
OXYGEN
PARTICLES
SUPERCRITICAL STATE
TEMPERATURE DEPENDENCE
WATER