Calcium magnesium acetate (CMA) is a deicer and can be used as an alternative to road salt. This is approximately as corrosive as normal tap water, and in various concentrations it can be effective in stopping the ice path from forming down to about -27.5 ° C (-17.5 ° F) (eutectic temperature). CMA can also be used as an arresting agent of H 2 S.
Video Calcium magnesium acetate
Production
CMA can be generated from the reaction of magnesium/calcium compounds with glacial acetic acid. If reacted with dolomite or dolomite lime, acetic acid does not need to be concentrated to produce CMA. The production of acetic acid requires the fermentation of organic material to be carried out at a pH of about 6.0. Therefore, the separating agent used to recover acetic acid must maintain a high temporary capacity in this pH range. Amberlite LA-2 in the 1-octanol diluent retains nearly full capacity to a pH value of 6.0 and is readily regenerated by aqueous dolomitic lime and formed to form CMA, making it a good acetic acid separation agent for CMA production.
Maps Calcium magnesium acetate
Use as road deicer
The sodium chloride road salt costs less than $ 50 per ton to produce but is corrosive to metals in the highway structure and increases the concentration of sodium in drinking water, which can cause adverse health effects. Alternative deicing substances have sought to address this problem. CMA has been found to be an effective and environmentally friendly deicer, although its production cost of $ 650 per tonne is much greater than the cost of road salt. Using estimates based on the New York State Data, a 1992 report in the Journal of Policy Analysis and Management concluded that $ 615 per tonne would be stored in vehicle corrosion and $ 75 per ton would be stored in aesthetic damage to a roadside tree if the state highway agency switched to using CMA as a deicer instead of a sodium chloride rock salt, far exceeding its initial production cost. The report also warned that excessive federal CMA subsidies could encourage excessive and inefficient use.
Use for H 2 S deletion
CMA has the ability to form highly sandy oxide particles when heated to high temperatures, containing thin, porous walls that are effective in capturing hydrogen sulfide from a temperature of 700-1100 ° C to 90%. The integrated gasification combined cycle system (IGCC) is used to convert coal into usable clean fuel gas which is then used to run the gas turbine system for power generation. An important step in this conversion process is removing the H 2 S and COS that are harmful to the environment from the gas formed from coal sulfur contained.
The desulfurization mechanism
CMA (CaMg 2 ) subtracts about 380-400 ° C to produce the following products: CaCO 3 , MgO, CH 3 COCH 3 , and CO 2 . CaCO 3 further decomposes about 700 ° C to CaO and CO 2 . The sulphidation reaction then occurs when CaO is reacted with H 2 S under reduced conditions in the gasifier, producing CaS and H 2 O. CaS ends up reacting with O 2 to produce an inert CaSO 4 which can then be removed.
References
External links
- Material safety data sheet
Further reading
Source of the article : Wikipedia
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