I have to dispose of 20.000 bbls of 40.000 ppm CaCl water. I dont have an injection well and would like to see if anybody has a better option than evaporation
Cost efficiency is also a must
Can't discharge to river or ocean? How about an evaporation Pond (if evaporation rate is higher than precipitation rate in your weather area)?
Ion exchange likely not a useful tool due to high concentrations already present.
Perhaps further concentration with electrodialysis or electrodialysis reversal, or reverse osmosis or pervaporation membrane? Then evaporate to dryness. Although, your stream is already rather concentrated.
Multiple effect evaporation system may be the best option. Expensive metallurgy, etc., but surprisingly efficient, at least when compared to just boiling water off in one stage. What else can one do and still obey laws of thermodynamics? It seems that this is what calcium chloride producers in the salt industry do.
Precipitate calcium as CaCO3? Even if possible at the high concentrations, Na2CO3 would surely need to be added, which would leave you with NaCl instead of CaCl .. not much further ahead? Total dissolved solids are not reduced.