Environmentally benign anti-icing or deicing fluids employing industrial streams comprising hydroxycarboxylic acid salts and/or other effective deicing/anti-icing agents

Abstract

The present invention provides novel deicing and anti-icing compositions and methods based on by-produce of off-specification materials from biodegradable and renewable sources and which also can be used in a variety of other services.

Description

FIELD OF THE INVENTION [0001] The present invention relates to deicing fluid compositions and methods for deicing surfaces and for preventing ice formation (anti-icing) on surfaces or within aqueous fluids and preventing crystal formation within non-aqueous fluids. More particularly the present invention relates to deicing / anti-icing fluid compositions comprising hydroxycarboxylic acid salts and / or other effective deicing and / or anti-icing agents obtained as products or by-products of industrial and / or fermentation processes. BACKGROUND OF THE INVENTION [0002] Freezing point lowering compositions are in widespread use for a variety of purposes, especially to reduce the freezing point of an aqueous system so that ice cannot be formed or to melt formed ice. Generally, freezing point lowering compositions depend for their effectiveness upon the molar freezing point lowering effect, the number of ionic species that are made available and the degree to which the compositions can be dispe...

AI Technical Summary

Benefits of technology

[0018] The present inventors have found that excellent deicing compositions comprising hydroxycarboxylic acid salts and / or other effective deicing / anti-icing agents can be obtained utilizing streams produced from, or process streams within, industrial and agricultural processes and in waste streams from such processes. Hydroxycarboxylic acids, their salts, their esters and other agents may be contained in said streams, or may be produced by at least partially reacting hydroxycarboxylic acid(s) or other acids contained in said streams to produce the corresponding salts or esters.

[0024] The compositions of the present invention further may comprise a variety of other materials to enhance the deicing and anti-icing performance, such as, but not limited to, coarse solids to improve vehicle traction, corrosion inhibitors to prevent or reduce vehicular and infrastructure corrosion and buffers to control the pH of the compositions.

[0025] The compositions and methods of the present invention can be applied to a wide variety of surfaces, including both metallic and non-metallic surfaces of aircraft, which prevents icing, removes frozen water from the surface and prevents its reformation. The invention provides for a deicing composition that can be used on airport runways, bridges, streets, other structures including power lines and industrial equipment such as the decks and exposed superstructure of ships, conveyor systems, storage facilities, support systems and the like. Further, the compositions can be used in heat transfer applications such as, but not limited to, automobile radiator coolants, air conditioner fluids and process heat transfer fluids, and in other applications in which it is vital or desired to maintain a liquid in the unfrozen or mobile state, e.g., as in a fire extinguisher, hydraulic fluids, pour point depressants or in well drilling work fluids, such as those used in drilling for oil and gas including completion fluids and workover fluids. This includes non-aqueous solutions, e.g., biodiesel or diesel fuel. Additionally, the present invention provides for an anti-icing composition that can be applied to a surface, such as bridges, prior to the onset of icing conditions in order to prevent icing from occurring.

Problems solved by technology

Chloride salts, however, suffer from relatively severe drawbacks, such as the harmful effects on surrounding vegetation by preventing water absorption in the root systems, the corrosive effects on animal skin, such as the feet of animals, clothing, roadways and motor vehicles, and the deleterious effects on surface and ground water.

Another drawback of certain prior art deicing fluids is their high chemical and biological oxygen demands, which make them environmentally unfavorable.

However, as mentioned above, these glycol compounds likewise have environmental drawbacks and can be detrimental to aquatic life and to sewage treatment processes.

Other prior art deicing fluids, such as mono and polyhydric alcohols, have toxic effects and high volatility particularly in the low molecular weight range.

Further, some of these may be the cause of offensive smells and fire danger.

Furthermore, mono- and polyhydric alcohols oxidize in the presence of atmospheric oxygen to form acids, which can increase corrosion of materials.

Back et al., U.S. Pat. No. 5,993,684, teach the use of non potassium, non-nitrogen organic salts having a molecular weight less than 201 in anti-icing or deicing applications, but does not teach the use of by-product streams from industrial or fermentation processes.

Further, Back teaches against the inclusion of potassium and halide salts or the use of glycol in formulations.

Further, Parks et al. do not teach the use of by-product streams from industrial or fermentation processes.

Further, Roe does not teach the use of by-product steams from industrial and fermentation processes.

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