Date of Award
5-1984
Document Type
Thesis
Degree Name
Master of Science (MS)
Abstract
The importance of determining the environmental effects of cooling water systems is increasing as the use of these systems for contaminated water circulation becomes more common. In order to predict these environmental effects it is necessary to obtain accurate characterizations of the emissions from these sources. Introducing wastewater streams to systems such as evaporative cooling towers necessitates an accurate determination of the composition of each phase of exhaust emission, as well as the quantity of emission.
The Great Plains Gasification Associates (GPGA) facility currently under construction in Mercer County, North Dakota includes a process cooling tower that will be operated using makeup wastewater generated in dry-ash lignite gasification. The GPGA tower is a 14 cell, 475,000 kg/min (126,000 gpm) circulation, forced-draft cooling tower; the wastewater makeup to it will be pretreated to an extent that makes tower operation feasible. The necessity for recycling this process stream sterns from a water deficiency in western North Dakota and from the plant ownership's commitment to a zero discharge facility.
The extent of wastewater pretreatment required is as yet unknown; therefore, a treatment train was constructed and operated to assess the effectiveness of phenol extraction and ammonia stripping to prepare the water for use as cooling tower makeup. The raw wastewater used at UNDERC was generated in slagging fixed-bed gasification of l ignite similar to that which will be used by GPGA. The effluent from the UNDERC extraction and stripping process, referred to as stripped gas liquor, or SGL, was used as makeup to a pilot scale cooling tower on site. This tower was operated at conditions simulating those planned for the GPGA tower in order to evaluate the feasibility of using SGL, which contains relatively high concentrations of ammonia, phenol and several other organics as makeup to their commercial cooling tower.
The objective of the present research was to evaluate the air stream sampling systems employed for measuring emissions from the UNDERC cooling tower and to determine the concentrations of various wastewater constituents found in the tower exhaust. In addition, these exhaust concentrations and quantities were used in conjunction with parameters of the GPGA cooling tower to predict plume dispersion from a similarly operated commercial cooling tower.
Recommended Citation
Galegher, Sheila J., "Atmospheric emissions from a gasifier wastewater fed cooling tower" (1984). Theses and Dissertations. 6635.
https://commons.und.edu/theses/6635
