Subcritical and supercritical water

Weber R, S Yoshida, K Miwa (2002) PCB destruction in subcritical and supercritical water—evaluation of PCDF formation and initial steps of degradation mechanisms. Environ Sci Technol 36 1834-1844. 

Peng, W., van der Kooi, H.J., Arons, J.D.S. 2004. Biomass conversions in subcritical and supercritical water driving force, phase equilibria, and thermodynamic analysis. Chem Eng Proc 43 1459-1467. 

Conversion of polymers and biomass to chemical intermediates and monomers by using subcritical and supercritical water as the reaction solvent is probable. Reactions of cellulose in supercritical water are rapid (< 50 ms) and proceed to 100% conversion with no char formation. This shows a remarkable increase in hydrolysis products and lower pyrolysis products when compared with reactions in subcritical water. There is a jump in the reaction rate of cellulose at the critical temperature of water. If the methods used for cellulose are applied to synthetic polymers, such as PET, nylon or others, high liquid yields can be achieved although the reactions require about 10 min for complete conversion. The reason is the heterogeneous nature of the reaction system (Arai, 1998). 

Li, L. et al., Kinetic model for wet oxidation of organic compounds in subcritical and supercritical water, Supercritical Fluid Eng. Sci., C24, 305-313, 1993b. 

Takahashi, Y. and Wydeven, T., Subcritical and supercritical water oxidation of cell model wastes, Adv. Space Res., 8, 99-110, 1989. 

Ferry JL, Fox MA. (1998) Effect of temperature on the reaction of HO center dot with benzene and pentahalogenated phenolate anions in subcritical and supercritical water. J Phys Chem A 102 3705-3710. 

Wu G, Katsiuniu-a Y, Muroya Y, Li X, Terada Y. (2000) Hydrated electron in subcritical and supercritical water A pulse radiolysis study. Chem Phys Lett 325 531-536. 

Feng J, Aki SNVK, Chateauneuf JE, Brennecke JF. (2002) Hydroxyl radical reactivity with nitrobenzene in subcritical and supercritical water. / Aw Chem Soc 124 6304-6311. 

M. Goemans, Diffusion Coefficients in Subcritical and Supercritical Water, Ph. D. Dissertation, The University of Texas at Austin, 1996. 

Yamaguchi, Y., Yasutake, N., Nagaoka, M. Ab initio study of noncatalytic Beckmann rearrangement and hydrolysis of cyclohexanone-oxime in subcritical and supercritical water using the polarizable continuum model. THEOCHEM 200Z, 639,137-150. 

Lee, J., and Teja, A. S. (2005). Characteristics of lithium iron phosphate (LiFePOJ particles synthesized in subcritical and supercritical water,... 

Another important area of polymer modification with subcritical and supercritical water is the hydrolysis of polycondensation polymers such as polyethylene terephthalate (PET), polyurethanes, and nylons for conversion to their monomers [ 37]. Specifically, in supercritical water, 91 % monomer recovery (terephthalic acid) is achieved at 400 °C and 400 bar in less than 15min reaction times [38]. Studies of these reactions using a hydrothermal diamond anvil cell to follow the phase changes during the reaction of PET... 

Another example of polymer modification reaction is the hydrolysis of cellulose in subcritical and supercritical water [40]. Cellulose is shown to hydrolyze rapidly (<1 s) in supercritical water in the absence of any catalysts to glucose, fructose, and oligomers (cellobiose, cellotriose, etc) with a hydrolysis product yield of about 75 % at 400 °C and... 

Ikushima, Y., Hatakeda, K., Saito, N. and Arai, M. (1998) An in situ Raman spectroscopy study of subcritical and supercritical water The peculiarity of hydrogen bonding near the critical point, J. Chem. Phys. 108,5855-5860. 

Ryan, E. T., Xiang, T., Johnston, K. P. and Fox, M. A. (1996) Excited-State Proton Transfer Reactions in Subcritical and Supercritical Water, J. Phys. Chem. 100,9395-9402. 

Among the nonphotochemical AOT s, one can distinguish the oxidation with Oj/OH", Oj/H O, Fenton s processes, electrochemical oxidation, radiolysis, plasma, ultrasonic treatment, etc. Among the photochemical processes, we can find the oxidation in subcritical and supercritical water, photolysis of water in UW, UV/H Oj, UV/O3, UV/H O /Oj, Photo-Fenton s processes, and heterogeneous photocatalysis. 

T Adschiri, K Kanazawa, K Arai. Rapid and continuous hydrothermal synthesis of boehmite particles in subcritical and supercritical water. J Am Ceram Soc 75 2615-2620, 1992. 

K Sue, Y Hakuta, RL Smith Jr, T Adschiri, K Arai. Solubility of lead(II) oxide and copper(II) oxide in subcritical and supercritical water. J Chem Eng Data 44 1422-1426, 1999. 

Jefferson W Tester, Jason A Cline. Hydrolysis and oxidation in subcritical and supercritical water connecting process engineering science to molecular interactions. Corrosion, 55(11) 1088-1100,1999. 

Wei Feng, Hedzer J van der Kooi, Jakob de Swaan Arons. Phase equilibria for biomass conversion processes in subcritical and supercritical water. Chemical Engineering Journal,... 

Properties of subcritical and supercritical water, CO2, and He-4 were obtained from NIST REFPROP software (2010). Properties of Na were taken from Kirillov et al. (2007). Properties of other coolants were calculated either using the original correlations presented in NEA (2007) or using correlations recommended by authors of this book. 

C. Liu, D. D. Macdonald, E. Medina, J. J. Villa and J. M. Bueno, Probing Corrosion Activity in High Subcritical and Supercritical Water through Electrochemical Noise Analysis, Corrosion, 50 (1994) 687. 

E.T. Ryan, T. Xiang, K.P. Johnston, M.A. Fox, Absorption and Fluorescence Studies of Acridine in Subcritical and Supercritical Water, J. 

Z. Han and Y. Muroya, Research and Development of a Super Fast Reactor (11) An Approach to Evaluate the Elution Characteristic of Stainless Materials in Subcritical and Supercritical Water, Frac. 16th PBNC, Aomori, Japan, October 13-18, 2008, P16P1315 (2008)... 

As for the available materials recommended for vessel internals, three factors will affect the properties and choice of the structural materials for the fahticatimi of RPV internals. These factors are the effects of irradiatimi, high temperature exposure, and interactions with both the subcritical and supercritical water environment to which they are exposed. An extensive testing and evaluation program will be required to assess the effects that these factors have on the properties of the potential materials for Super LWR construction to enable a preliminary selection of the most promising materials to be made and to then quaUly those selected for the service conditions required. 

Xu CB, Lee J, Teja AS (2008) Continuous hydrothermal synthesis of lithium iron phosphate particles in subcritical and supercritical water. J Supercrit Fluid 44 92-97... 

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