Freezing and flash points of ethanol based water solutions or brines
Ethanol based Water Solutions Freezing Point
(% by volume)
Flash Points of Ethanol based Water Solutions
The flash point of a chemical is the lowest temperature where it will evaporate enough fluid to form a combustible concentration of gas. The flash point is an indication of how easy a chemical may burn.
(% by weight)
- HIGH flammability if pure
Alternatives to Ethanol based Water Solutions
- Ethylene glycol based water solutions
- Propylene glycol based water solutions
- Methanol based water solutions
Example - Ethanol Concentration at Freezing Point at -20oC
The ethanol concentration with freezing point at -20oC can be calculated by interpolating the concentration between freezing point -15oC and -23oC in the table above.
(((40%) - (30%)) / ((-23oC) - (-15oC))) ((-15oC) - (-20oC)) + (30%) = 36.25 %
This calculation is simplified by assuming that the concentration vs. freezing point follows a straight line. This not necessary correct.
If a 90% ethanol-water solution shall be mixed with clean water to achieve a freezing point of -20oC (ethanol concentration 36.25% (0.3625)) - the amount of added water can be calculated with volume balance - the amount of ethanol before mix is the same as after the mix:
cs Vs = cm (Vs + Vw) (1)
cs = concentration in ethanol - water solution
Vs = volume of the ethanol - water solution (liter, gallon)
cm = concentration in mix
Vm = volume of mix (liter, gallon)
Vw = volume of the added clean water (liter, gallon)
Rearranging the equation to express the volume of water added to the mixture
Vw = (cs - cm) Vs / cm (1b)
Substituting with values
Vw = (0.9 - 0.3625) Vs / 0.3625
= 1.48 Vs
- for every liter 90% ethanol-water solution 1.48 liter of clean water must be mixed in to achieve an ethanol concentration of 36.25 % and freezing point -20oC.