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Title: Oxidation of phenolics in supercritical water. Quarterly technical progress report, March 1, 1994--May 31, 1994

Abstract

An environmental hazard associated with coal liquefaction and gasification is the generation of aqueous waste streams containing phenolics and carcinogenic organics such as polynuclear aromatics. Oxidation in supercritical water (SCW) is an emerging technology for the ultimate destruction of phenolics and other organics in waste water streams. SCW oxidation involves the oxidation of organics in an aqueous medium at temperatures between 400-650{degrees}C and pressures around 250 atm. These conditions exceed the thermodynamic critical point of water, hence the water is said to be supercritical. Wastes can be converted by SCWO to benign products: carbon is converted to CO{sub 2}, hydrogen to H{sub 2}O, and nitrogen to N{sub 2} or N{sub 2}O (but not NO{sub X}). SCWO possesses several attractive features. (1) The effluents from the SCWO process can be collected or held in a recycle loop so the process can be easily {open_quotes}bottled up{close_quotes} with no uncontrolled emissions should an upset occur. (2) The oxidation reaction is exothermic, so it is possible to operate the SCWO reactor in an autothermal mode. That is, the oxidation of the organic material in the aqueous stream liberates sufficient heat to maintain the elevated reactor temperature and also preheat the feed. Thus, after start-up,more » the process would not require an external energy source and could even be used to produce energy provided the organics content in the feed stream was sufficiently high. (3) Operating at supercritical conditions also provides a single, homogeneous fluid phase in the reactor. Indeed, water above its critical point has a high solubility for organics, and it is totally miscible with oxygen. (4) The temperature in SCWO is high enough to provide rapid reaction rates but not so high that alloys begin to lose their mechanical strength. Thus, the oxidation of organics goes essentially to completion in a very short time (a few seconds).« less

Authors:
Publication Date:
Research Org.:
Michigan Univ., Ann Arbor, MI (United States). Dept. of Chemical Engineering
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10182479
Report Number(s):
DOE/PC/92536-T7
ON: DE94018848; TRN: 94:008194
DOE Contract Number:  
FG22-92PC92536
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1994]
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; PHENOLS; OXIDATION; WASTE WATER; PURIFICATION; PROGRESS REPORT; COAL LIQUEFACTION; COAL GASIFICATION; 010800; WASTE MANAGEMENT

Citation Formats

Savage, P E. Oxidation of phenolics in supercritical water. Quarterly technical progress report, March 1, 1994--May 31, 1994. United States: N. p., 1994. Web. doi:10.2172/10182479.
Savage, P E. Oxidation of phenolics in supercritical water. Quarterly technical progress report, March 1, 1994--May 31, 1994. United States. https://doi.org/10.2172/10182479
Savage, P E. 1994. "Oxidation of phenolics in supercritical water. Quarterly technical progress report, March 1, 1994--May 31, 1994". United States. https://doi.org/10.2172/10182479. https://www.osti.gov/servlets/purl/10182479.
@article{osti_10182479,
title = {Oxidation of phenolics in supercritical water. Quarterly technical progress report, March 1, 1994--May 31, 1994},
author = {Savage, P E},
abstractNote = {An environmental hazard associated with coal liquefaction and gasification is the generation of aqueous waste streams containing phenolics and carcinogenic organics such as polynuclear aromatics. Oxidation in supercritical water (SCW) is an emerging technology for the ultimate destruction of phenolics and other organics in waste water streams. SCW oxidation involves the oxidation of organics in an aqueous medium at temperatures between 400-650{degrees}C and pressures around 250 atm. These conditions exceed the thermodynamic critical point of water, hence the water is said to be supercritical. Wastes can be converted by SCWO to benign products: carbon is converted to CO{sub 2}, hydrogen to H{sub 2}O, and nitrogen to N{sub 2} or N{sub 2}O (but not NO{sub X}). SCWO possesses several attractive features. (1) The effluents from the SCWO process can be collected or held in a recycle loop so the process can be easily {open_quotes}bottled up{close_quotes} with no uncontrolled emissions should an upset occur. (2) The oxidation reaction is exothermic, so it is possible to operate the SCWO reactor in an autothermal mode. That is, the oxidation of the organic material in the aqueous stream liberates sufficient heat to maintain the elevated reactor temperature and also preheat the feed. Thus, after start-up, the process would not require an external energy source and could even be used to produce energy provided the organics content in the feed stream was sufficiently high. (3) Operating at supercritical conditions also provides a single, homogeneous fluid phase in the reactor. Indeed, water above its critical point has a high solubility for organics, and it is totally miscible with oxygen. (4) The temperature in SCWO is high enough to provide rapid reaction rates but not so high that alloys begin to lose their mechanical strength. Thus, the oxidation of organics goes essentially to completion in a very short time (a few seconds).},
doi = {10.2172/10182479},
url = {https://www.osti.gov/biblio/10182479}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 1994},
month = {Thu Sep 01 00:00:00 EDT 1994}
}