Pilot-scale treatment of gasification wastewater and reuse in a cooling tower

Conference · Mon Apr 01 00:00:00 EST 1985

OSTI ID:5746070

Willson, W G; Mayer, G G; Hendrikson, J G; Winton, S L

The University of North Dakota Energy Research Center has operated a 910 kg/hr, oxygen-blown fixed-bed gasifier to produce lignite-derived effluents for characterization, treatment, and reuse studies. Reuse of waste water in a cooling tower was investigated to define environmental and process effects as a function of pretreatment. The gasification wastewater was pretreated in pilot wastewater treatement units which simulate available technology. During the first phase of the program, wastewater was pretreated by solvent extraction and steam stripping to produce phenol and ammonia concentrations comparable to those expected at the Great Plains Gasification Associates plant. This pretreated wastewater was concentrated in a cooling tower to 10 cycles of concentration. No biocides or corrosion inhibitors were added. Severe fouling of heat exchange surfaces and high corrosion rates of carbon steel were encountered. Over 90% of the phenol entering the cooling tower was found to be stripped into the cooling tower exhaust air stream. The high levels of organics remaining in this minimally treated wastewater suggested that further biological treatment and possibly polishing by carbon adsorption would be necessary to prepare a satisfactory feed. In the second phase of the program, the SGL was further treated in an activated sludge process followed by granular activated carbon adsorption. Biotreatment removed 96% of the BOD with a three-day retention time while obtaining satisfactory sludge settling rates in spite of varied influent concentrations. Biorefractory materials were adsorbed on GAC to reach an effuent COD level of 150 mg/l. This upgrading was sufficient to reduce organic emissions from the cooling tower, but corrosion rates were higher than in the previous test, again showing the necessity for corrosion inhibitors. 8 figs., 3 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy Research Center; Radian Corp., Austin, TX (USA)
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 5746070
• Report Number(s): DOE/FE/60181-74; CONF-850463-1; ON: DE85010900
• Resource Relation: Conference: 11. Australian Water and Wastewater Association international convention, Melbourne, Victoria, Australia, 28 Apr 1985
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
AMMONIA
REMOVAL
COAL GASIFICATION
WASTE WATER
PHENOLS
RECYCLING
WATER TREATMENT
CHEMICAL COMPOSITION
COOLING TOWERS
CORROSION
LIGNITE
PILOT PLANTS
AROMATICS
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
ENERGY SOURCES
FOSSIL FUELS
FUELS
FUNCTIONAL MODELS
GASIFICATION
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIQUID WASTES
MATERIALS
MECHANICAL STRUCTURES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
THERMOCHEMICAL PROCESSES
TOWERS
WASTES
WATER
010404* - Coal
Lignite
& Peat- Gasification
010800 - Coal
Lignite
& Peat- Waste Management