Combustion of coal particles in H{sub 2}O/O{sub 2} supercritical fluid
- Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophyics
Combustion of single coal particles of 1-5 mm diameter in H{sub 2}O/O{sub 2} supercritical fluid with a mass share of oxygen of 0-6.6%, pressure of 30 MPa, and temperature of 400-750{sup o}C was studied in the semi-batch reactor. A decrease in coal mass was observed in two parallel processes: gasification by water and oxidation by oxygen. With an assumption of zero order in H{sub 2}O concentration and Arrhenius dependence for the rate of gasification by water, the activation energy was estimated as 19 kJ/mol and the pre-exponential factor was determined as 1.02 x 10{sup -2} s{sup -1}. It was found out that oxidation by oxygen under the temperature of above 500{sup o}C is limited by the rate of O{sub 2} diffusion to combustible coal residue. Below 500{sup o}C the rate of heterogeneous oxidation by oxygen is described by the first-order reaction in concentration of O{sub 2} and zero-order reaction in concentration of H{sub 2}O with activation energy of 166 kJ/mol and pre-exponent of 1.5 x 10{sup 8} cm{sup 3}/g.s.
- OSTI ID:
- 20923913
- Journal Information:
- Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 13 Vol. 46; ISSN IECRED; ISSN 0888-5885
- Country of Publication:
- United States
- Language:
- English
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