A computational model for supercritical water oxidation of organic toxic wastes.pdf

Advances in Environmental Research 4Ž. 2000 79᎐95
putational model for supercritical water
oxidation anic toxic wastes
Ning Zhoua,U, Anantha Krishnana, Frederic´´ Vogelb, William A. Petersb
a CFD Research Corp., 215 Wynn Dr., Hunts¨ille, AL 35805, USA
., Energy Laboratory, 1 Amherst Street, Cambridge, MA 02139, USA
Accepted 13 March 2000
Abstract
putational fluid dynamicsŽ. CFD model was proposed to simulate the supercritical water oxidation Ž SCWO .
process anic wastes. The SUPERTRAPP codeŽ. by NIST for thermodynamic and transport properties of
hydrocarbon mixtures was incorporated into mercialized general purpose CFD code CFD-ACE for flow
under supercritical pressure. The global ic models for supercritical water oxidation of methanol and methane
at MIT Energy Lab were implemented and validated in the CFD-ACE framework against experimental
data from a tubular reactor. A series of parametric studies to investigate flow rates, thermal boundary conditions and
reactor geometry was performed for methane SCWO in a co-axial reactor and the optimized operating conditions
and reactor geometry were obtained. Detailed three-dimensional flow, heat and chemistry simulations of methanol
SCWO in the CSTR at MIT Energy Lab were also performed with predicted parable to measure-
ments. ᮊ 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Supercritical water oxidation; Computational fluid dynamicsŽ. CFD ; Simulation; Organic waste
1. Introduction Supercritical waterŽ. SCW , . water above its criti-
cal temperature and pressureŽ. 374ЊC, 221 bar , exhibits
Supercritical water oxidationŽ. SCWO has emerged properties very different from those of water at stan-
in recent years as a promising technology for the de- dard conditions. For example, at 550ЊC and 250 bar,
struction of anic materialsŽ Modell, 1989; water density, static dielectric constant, ionic dissocia-
y
Buelow et al., 1990; Shaw et al., 1991; Tester et al., tion const