Treatment alternatives for FGD blowdown 1

[wtflippin]

I am looking for treatment alternatives for the blowdown stream (8,000 ppm Chlorides) from a typical coal plant FGD system. Discharge offsite is not an option. We are currently considering an evaporator, using the concentrated waste stream to stabilize the byproduct storage area (ash). Any experience/lessons learned would be appreciated.

 

[SlideRuleEra]

wtflippin - I also worked in the construction division of an electric utility. In the early 1980's, at a new plant, we installed a proprietary system (from Conversion Systems, Inc.) to dewater FGD sludge, mix it with fly ash, lime and water to make a stabilized landfillable waste product, "Poz-O-Tec". For 15 years, results were satisfactory, but the system required a dedicated operating staff and much maintenance. There was hope that a market for the material as a road base would develope, but it did not. Here is a link to general information

http://www.rmrc.unh.edu/Partners/Userguide/fgd2.htm

In the late 1990's this system was converted to produce synthetic gypsum for resale. Operation has been successful, two new coal-fired plants under construction will also produce synthetic gypsum. Also an existing four-unit station is having a synthetic gypsum plant retrofitted. Here is a link for information at a different electric utility (my former employer has not posted any details)

http://www.seminole-electric.com/sections/generation/public/gypsum.htm

Best Wishes

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