What are the differences between methanol-water, ethanol-water, and ethylene glycol-water solutions as cooling and heating media?
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What are the differences between methanol-water, ethanol-water, and ethylene glycol-water solutions as cooling and heating media? Please, experts, explain in detail. Thank you for your help!
The expert hasn’t shown up yet; looking forward to replies from below. Thanks for the help.
Management, please help – don’t let this post get buried. Thank you! :Handshake – an authoritative answer is needed
It’s over; no one can answer this post, it’s completely doomed :(
It is likely due to differences in freezing point and viscosity; the viscosity of an ethylene glycol aqueous solution becomes very high at -30 degrees, which results in a significant increase in pump power, while the viscosity of a methanol aqueous solution is lower.
However, at higher temperatures, ethylene glycol, ethanol, and methanol are oxidized to their corresponding acids. In terms of acidity, oxalic acid (first dissociation) > formic acid > oxalic acid (second dissociation) > acetic acid; this likely results in different levels of corrosion to the equipment
1. This liquid is designed to be used at lower temperatures, and oxidation hardly occurs. 2. The use of alcoholic aqueous solutions as a coolant is intended to replace saltwater coolants such as calcium chloride, thereby avoiding equipment corrosion ； 3. Moreover, the methanol dehydration unit is made of ordinary carbon steel, and no corrosion has occurred despite years of operation. The low-temperature water in the polypropylene plant is a 40% methanol aqueous solution.
Then, doesn’t an ethanol aqueous solution have better properties in every aspect compared to a methanol aqueous solution? Why is a methanol aqueous solution chosen instead of an ethanol aqueous solution? ? To put it another way, even if oxidation occurs in a timely manner, acetic acid is much less acidic than formic acid, right?
Methanol is toxic and corrosive, as is ethanol. It is quite rare to use these two substances as cooling or heating media. After doing some research online, I found that ethanol can be used as a quaternary cooling agent. Ethanol has a low flash point, so its use increases the level of risk; however, if proper explosion-proof measures are in place, it can be used to some extent. It should be noted that both ethylene glycol and ethanol are corrosive to carbon steel. You can search for “corrosion caused by ethylene glycol solutions” on Baidu, where you will find many relevant papers.
1. All three of these liquids can be used for heat transfer; methanol and ethanol cannot be used for heat conduction, while ethylene glycol can. 2. Methanol and ethanol are flammable and explosive liquids, whereas ethylene glycol solutions are relatively safer. 3. Over time, all three of these liquids will become acidic, which can cause corrosion to the metals they come into contact with. 4. If heat transfer media are needed, it is possible to contact specialized manufacturers in this field, such as Chaoyang Guangda Chemical Industry – you might want to check them out.