Then why are we passing seawater through pressurized filters instead of freezing it to get fresh water?
>>16794868Energy requirement, boiling it also works but takes even more energy.
>>16794887>boiling >takes even more energyanon, do you know how much energy is needed to boil water vs freezing it? it's a LOT MORE. see pic.let's say your water temp is 20°C. you'd need to heat it to 100°C and then evaporate it. that'd be 100[cal/g/°C] x 80°C + 540 [cal/g] per gram of watermeanwhile, fusion requires even less energy than cooling the water from 20°C to 0°C
>>16794868You'd have to freeze it, move the solid somehow, and then thaw it. The engineering would be more complicated than just using a membrane for a liquid or directly using the heat from a power plant to boil it and drain off the brine when done.
>>16795588right, that's a great explanation actuallystill, people some places might want to use seawater rather than membranes, simply because that's what's available. like, who the f doesn't have a fucking fridge at home? even during droughts...
>>16795168Producing heat is easy. Producing cold temperatures require chemicals. Boiling water is more eco friendly
>>16794868Distilling by freezing requires a temperature around -5 C and is actually quite slow as the sailine drains from the porous ice. The ice needs to be removed and concentrated sailine flushed and replaced with new feedstock. Also the ice generated is still salty.It is energy intensive and the cold sailine should precool the incoming feedstock in a regenerator. There's a lot of concerns compared to reverse osmosis.
>>16795870>Boiling water is more eco friendlyIn the Arctic or Antarctic frozen lakes, rivers or sea ice can be harvested directly and this is economical and ecological.Boiling to distill is also energy intensive because you're bringing sailine from 20C up to ~99C and then pay the heat cost of vaporization.
>>16794868OP here. here's a recent paper (by researchers from hong kong university of science and technology) I just found while googlinghttps://www.sciencedirect.com/science/article/abs/pii/S0043135422013343the authors show a new(?) way of generating ICE by flowing seawater and also simulating pressurizing seawater with pistons, and (as far as I understand) discuss ice formation rates regarding Na/CL ion rejection and temperature of water in the surface. flowing seawater doesn't even need to be at freezing temp (see pic)oddly, I haven't found any "pop sci" references to this paper.>>16795878>Distilling by freezing requires a temperature around -5 C and is actually quite slowisn't this why they "seed" the process with small piece of ice? I learned that from this paper: https://www.nature.com/articles/s41545-022-00158-1>It is energy intensivesure, but is it as energy intensive as reverse osmosis or more?>the cold sailine should precool the incoming feedstock in a regeneratorcould't you also transfer energy to the ice by heating it with the incoming feedstock to melt it while also cooling incoming salt water?
>>16794868Saltwater is yummy, just trust your metabolism to filter out the excess salts, and enjoy the extra electrolyte boost from nature’s abundance.
>>16796176>https://www.sciencedirect.com/science/article/abs/pii/S0043135422013343samefag here... I just finished reading the paper and they claim their method + setup reached an efficiency of 9.26kWh/ton = 9.26kWh/m3, which they say is better than that of other freeze desalination methods, though google says it's not really as good as reverse osmosis(1.861 kWh/m3 in https://www.danfoss.com/en/about-danfoss/articles/hpp/a-new-world-record-in-swro-energy-efficiency-underscores-the-enormous-potential-of-updating-existing-desalination-plants-with-best-in-class-technology/)
Fresh water literally falls from the fucking sky. Nobody is going to harvest blocks of ice from the fucking arctic.
>>16796196this was their setup, btw. oddly, they use θ = 10°C even though their experiments show a θ producing better results>>16796184>>16796203ok.
