Oxidation kinetics of methylphosphonic acid in supercritical water : experimental measurements and model development

(cont.) at well-defined operating conditions and to develop. both microscopic and macroscopic models, ranging from regressed global models to an elementary reaction mechanism, to quantify MPA oxidation kinetics in supercritical water. MPA hydrolysis and oxidation rates were experimentally measured in a laboratory-scale plug flow reactor. The effects of MPA concentration (0.5 to 1.0 mM), oxygen concentration (1.0 to 3.8 mM), temperature (478 to 572⁰C) and pressure (138 to 277 bar) on oxidation rates were determined for residence times ranging from 3.0 to 9.5 s. Conversion due to hydrolysis was less than 6% after [tau]=7 s at all temperatures studied. For [tau]=7 s at stoichiometric conditions and P=246 bar, low conversion (X<30% at [tau]=10 s) was observed at T<503⁰C, while almost complete conversion (X=99%) occurred at T=571⁰C. The only phosphorus-containing product was phosphoric acid, while the carbon-containing intermediates, carbon monoxide and methane, were present in varying concentrations in addition to final carbon-containing product, carbon dioxide. Methane was only a minor product, with a carbon yield less than 20% at all experimental conditions. MPA oxidation rates varied with oxygen concentration and pressure (or water density), but were relatively independent of initial MPA concentration. A global MPA oxidation rate law was regressed from the data with its dependence on temperature, MPA concentration, oxygen concentration, and water concentration quantified ...

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Chemical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Sullivan, Patricia A. (Patricia Ann), 1978-

Advisor dc:contributor.advisor

• Jefferson W. Tester.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28305

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28305