Method and system for suppression of foam of waste streams
AssigneeThe Scientific Ecology Group, Inc.
InventorsTerry R. Galloway, Thomas J. Green
Life of this patent
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Abstract
A method and a system is disclosed for the suppression of foams during the processing of streams containing waste materials. An additive is introduced into a waste stream and the waste stream is processed for a period of time at an elevated temperature and substantially atmospheric pressure. The tendency toward foam formation is suppressed by particles from the additive becoming suspended in the waste stream. The waste materials containing a substantial reduction of foam are removed from the processing system without the usual spattering and formation of sticky residue which causes fowling and frequent shutdowns of the processing system.
Claims14
A method for the suppression of foams during the processing of streams containing waste materials which comprises
- (a) introducing an additive powder into a waste stream comprising diammonium ethylenediaminetetraacetic acid at a concentration in the range of 0.5% to 20% by weight, said additive having the stability to withstand thermal and chemical degradation during the processing;
- (b) processing said waste stream for a period of time at a temperature in the range of about 95.degree. C. (203.degree. F.) and about 760.degree. C. (1400.degree. F.), wherein a foam of said waste stream has the tendency of forming;
- (c) suppressing the formation of said foam by at least a portion of said additive powder in the form of particles having a size in the range substantially less than 100 .mu.m where the additive powder is suspended in the liquid cells between bubbles that make up the foam structure, where the particles act as ionic or polar sites to attract and neutralize surfactants creating foam, and any remaining portion of said additive being solubilized in the waste stream to such an extent that said particles do not coagulate and precipitate out of solution;
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- (d) removing said waste containing a substantial reduction of foam.
A method for the suppression of foams in the stream reforming of waste streams which comprises:
- (a) introducing an additive powder into a waste stream comprising diammonium ethylenediaminetetraacetic acid, said additive selected from the group consisting of sawdust, corn meal, flour, titanium dioxide, molybdenum disulfide, said fines, grinding compounds, clays, polishing compounds, cellulose acetate and mixtures thereof, wherein said additive is emulsified with at least a portion of said waste stream, the resulting emulsion having a concentration of up to 70% by weight of said additive.
- (b) steam reforming said waste stream in a steam reforming vessel at a temperature in the range of about 230.degree. C.(450.degree. F.) to about 760.degree. C. (1400.degree. F.), a pressure in the range of about 70 kPa, to about 150 kPa, wherein a foam of said waste stream has the tendency of forming, and a concentration of said additive in said waste stream in the range of about 0.5% to about 30% by weight;
- (c) suppressing the formation of said foam by at least a portion of said additive powder in the form of particles having a size in the range substantially less than 100 .mu.m where the additive powder acts as sites to attract and neutralize surfactant materials creating foam, where the additive powder is suspended in liquid cells between bubbles that make up the foam structure, and where the particles act as ionic or polar sites to attract and neutralize surfactants creating foam, and any remaining portion of said additive being solubilized in the waste stream to such an extent that particles do not coagulate and precipitate out of solution;
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- (d) recovering said solid waste residue containing a substantial reduction of foam.
Dependencies are inferred from the claim text.