Abstract: Improved deicer compositions containing crystalline double salts formed from mixtures of relatively low molecular weight carboxylic acids (for example, mixtures of formic acid and acetic acid) are provided. The deicer compositions are generally prepared by neutralizing an aqueous mixture containing at least two carboxylic acids or salts thereof, adjusting the pH to between about 7 and about 10, and drying the aqueous mixture to obtain a double salt crystalline product. Double salts containing sodium cations and double salts containing sodium cations and at least one cation selected from the group consisting of potassium, calcium, and magnesium provide effective deicing compositions which are environmentally safer than conventional deicing compositions.
Type:
Grant
Filed:
September 9, 1993
Date of Patent:
December 27, 1994
Assignee:
State of South Dakota as represented by the Department of Transportation
Abstract: Deicing chemicals intended primarily for decing pavement such as roads, bridges, and runways are prepared from polysaccharide sources (e.g., waste products such as sawdust) by reaction at a pressure of less than 600 psi and a temperature less than 200.degree. C. with a treating agent comprising alkali metal carbonates or bicarbonates or a mixture thereof and excess oxygen in the presence of water followed by the removal of oxalate and the treating agent. The reaction produces a liquid or a liquid/solid reaction product wherein the liquid contains the deicing chemical and the solid comprises a valuable pulp by-product. Calcium oxide or calcium hydroxide may be added to reduce the pressure resulting from the formation of large amounts of carbon dioxide during the reaction process and to aid in the removal of any oxalic acid formed during the reaction process.
Type:
Grant
Filed:
September 28, 1984
Date of Patent:
May 12, 1987
Assignee:
State of South Dakota as represented by the Department of Transportation
Inventors:
Robert L. Sandvig, William A. Klemm, Jack R. Gaines, Robert W. Looyenga
Abstract: De-icing chemicals intended primarily for de-icing pavement such as roads, ridges, and runways are prepared from polysaccharide sources (e.g. waste products such as sawdust) by reaction at elevated pressure and temperature with alkaline earth metal oxides or hydroxides in the presence of water. The de-icing chemicals are impure mixtures of alkaline earth metal salts of acetic acid, lactic acid and glycolic acid with the mixture being substantially free of alkaline earth metal salts of oxalic acid and formic acid. The de-icing chemicals are intended to be a substitute for the inorganic chloride salts (e.g. sodium chloride) commonly used for de-icing highways.
Type:
Grant
Filed:
January 12, 1982
Date of Patent:
February 7, 1984
Assignee:
State of South Dakota as represented by the Department of Transportation
Inventors:
Robert L. Sandvig, William A. Klemm, Jack R. Gaines, Robert W. Looyenga