Phenol extraction studies: solvent screening, tar acid removal, and organic volatilization. Final technical report
This report summarizes three studies to assess the feasibility of pretreating wastewater from the SRC-I Demonstration Plant with solvents to remove phenolic materials. One series of tests evaluated the extraction efficiency of three solvents (diisopropyl ether, methyl isobutyl ketone, and N-butyl acetate) on SRC-I wastewater obtained from the Ft. Lewis pilot plant. Solvent extraction was deemed feasible, but not without resolving the effect of pH on extraction and the fate of tar acids during extraction. Tar acids are a complex mixture of unidentified organic compounds that can be precipitated out of water at an acidic pH. A second set of extraction screening experiments was run with SRC-I hydrotreater unit and H-Coal wastewaters; tests were also run with those samples and SRC-I water to evaluate tar acid removal at different pH values. Phenol removal from SRC-I water was feasible but pH-dependent. In general, the extraction characteristics of phenol, pyridine, and aniline with the various solvents were consistent with other experimental observations for coal-conversion wastewater. The three samples exhibited markedly different tar acid properties. A third series of tests determined the amount of tar acid material that can be removed by acidifying the different wastewaters, and how solvent extraction affected the quantity of tar acid. Results showed that acidification of the raw SRC-I wastewater removed about 10 g/L of tar acid, and that H-coal wastewater contained much less tar acid. Solvent extraction did reduce the quantity of tar acid significantly. Solvent extraction also markedly reduced the amount of organics volatilized during steam-stripping. Screening tests showed reductions ranging up to a factor of approximately 20 for extracted water, free of residual solvent, in comparison with raw wastewater. 11 references, 8 figures, 21 tables.
- Research Organization:
- Carnegie-Mellon Univ., Pittsburgh, PA (USA). Dept. of Civil Engineering
- DOE Contract Number:
- AC05-78OR03054
- OSTI ID:
- 5070771
- Report Number(s):
- DOE/OR/03054-88; ON: DE84011851
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL TAR ACIDS
REMOVAL
PHENOLS
SRC PROCESS
DEMONSTRATION PLANTS
WASTE WATER
SOLVENT EXTRACTION
WATER TREATMENT
COAL LIQUEFACTION
EVAPORATION
PRECIPITATION
AROMATICS
EXTRACTION
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIQUEFACTION
LIQUID WASTES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SEPARATION PROCESSES
THERMOCHEMICAL PROCESSES
WASTES
WATER
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction