Investigation of the Conditions for the Production of Calcium Magnesium Acetate (CMA) Road Deicer in an Extractive Crystallization Process

Abstract

Calcium magnesium acetate (CMA) is considered as the best road deicer to replace the environmentally unacceptable NaCl and CaCl2. However, the high cost of CMA prohibits its widespread use. The present study is dealing with the investigation of a crystallization method for the production of deicing CMA crystals of desired physical properties and the elucidation of the conditions under which such a product can be formed. Extractive crystallization is promising for the low cost production of CMA crystals considering that acetic acid is produced by a biochemical method and removed from the fermentation broth in situ by organic extractant systems. In this method, this organic phase, which contains the acetate ions is contacted with an aqueous phase which is the source of calcium and magnesium ions. The extractive crystallization process resulted in the production of well‐formed, large, and non‐spherical crystals of calcium acetate (CA), magnesium acetate (MA), and calcium magnesium acetate double salt (CMADS). The crystal size was affected by the concentration of acetic acid in both the organic and aqueous phases, whereas the crystal type and hydration level were determined primarily by the acetic acid concentration in the aqueous phase. The molar ratio of the precursor salts (CaCO3/MgCO3) in the reaction mixture was found to be the major factor for determining the habit and Ca/Mg content of crystals. Crystallization of CMADS was favored at high concentrations of acetic acid in the aqueous phase and at higher temperatures as shown from supplementary evaporation‐to‐dryness experiments.

Unconventional Approach for Demineralization of Deproteinized Crustacean Shells for Chitin Production

“…In 1979,calcium magnesium acetate was identified as a non-corrosive environmentally-friendly alternative to chloride salts for road de-icing practices [26] . The major disadvantage of CMA is its relatively high production cost, which is mainly attributed to the cost of acetic acid [27] . Yang et al [28] stated that acetic acid used to produce calcium magnesium acetate, as a road de-icer, pure as acetic acid used in the chemical industry.…”

“…Producing acetic acid from cheese whey could reduce its production cost significantly. The use of acetic acid for the demineralization of shrimp shells in the ratio of 1 g Table 6: Solubilities a of some salts in water at various temperatures [29] Temperature (˚C) Substance Formula Dionysiou et al [27] stated that the following reactions can occur:…”

Phase Diagram of Ternary Calcium Acetate—Magnesium Acetate—Water System at 298 K, 313 K and 323 K

“…[8][9][10][11][12][13] A commercial method of making CMA involves formation of the CMA in an aqueous environment in which all the reactants are soluble and in equilibrium with the CMA product, thus resulting in a CMA-containing solid, which is contaminated, in various amounts, with calcium acetate and magnesium acetate. Particularly, Fu Su et al [12] directly used calcium acetate and magnesium acetate as raw materials reaction with glacial acetic acid to produce calcium magnesium acetate.…”

Changes in Water Quality in an Urban Stream Following the Use of Organically Derived Deicing Products

“…Numerous articles have inferred substantial negative environmental implications of using road salt (Horner and Brenner 1992, Environmental Protection Agency 1999, Ormsby 1999, Dionysiou et al 2000. However, evidence of the scope of this claim seems unsubstantiated.…”