De-icers derived from corn steep water

Abstract

Corn steep water (CSW) and other byproducts derived from fermentations and sugar productions are presently forming the base of compositions for de-icing and anti-icing materials. Since the de-icing and anti-icing values are in part a colligative property, increase in the molar concentration of ionic species has been frequently necessary to decrease further the freezing point of this byproducts stream. In the present study this has been achieved by the generation of biodegradable organic acid salts in situ, without the use of chloride or other inorganic salts, by the alkaline degradation of reducing sugars added to corn steep water, which alone is not an efficient de-icer. Reducing sugars, such as glucose, react with alkali metal hydroxides to produce principally hydroxy carboxylic acids that react with the alkali metal hydroxide to form a mixture of organic acid salts. The ionic strength of the resulting solution is increased since each sugar molecule produces nearly two acid molecules upon degradation. The ionic strength necessary to achieve the desired freezing point depression is determined by the amount and concentration of the alkali metal hydroxide used, with the necessary counter anions being derived from the degradation of the reducing sugar. The amount of the sugar used is that required to result in a near to neutral final solution. The well-known anti-corrosive property of CSW is used in the de-icer preparations, either by conducting the alkaline degradation of the sugar in this medium, or by using water for the degradation of the sugar followed by dilution of the resulting solution with CSW to adjust the viscosity of the final solution to meet the requirements for spraying. The monovalent metal hydroxides are more efficient in producing de-icer solutions than the divalent metal hydroxides.