I believe it is true. The volume of water is staggering. The previous article talked about it being necessary to return the briny water over a large area to reduce the environmental impact. And like jmakin said, the current methods take a huge amount of energy.
1 Like
Right now desalination plants dump their brine back into the ocean which costs additional energy to pump it out and is pretty deadly to marine life if dumped too fast in too small an area. Better option is to covert it into other chemicals. Some of the chemicals you can extract are used by the plant itself so it make sense to do it but extracting chemicals also takes energy making it not really economical to do so at this time.
So many things we can do better if energy is green and cheap and plentiful.
3 Likes
Yeah, marine life is pretty well optimized around the current level of salinity, and there isn’t much room for fluctuations up or down before things die. Salmon are actually pretty fucking weird that they can survive in both salt water and fresh. Like, you can go in both, but you don’t have to breathe it. Stuff that has to breathe it is breathing the salt content as well. Life is sensitive enough that you can measure meaningful changes in microbial content all the way along as you move out from a river into an estuary and into the ocean. As Dutch said, dumping a bunch of salt or high salt water into one spot next to a plant has a good shot of killing ~everything if the scale is large enough.
2 Likes
I realize this is “I’ve read 5 minutes on this topic and there am expert” territory, but most plants don’t just spit the brine back out anymore right…
Honestly I don’t know, but I do believe in conservation of mass, so it has to go somewhere. There are a lot of bad options, and I’m not sure how easy it is to turn it into sea salt that is safe for human consumption. I chimed in mainly because I know something about marine metagenomics as a function of salinity more than anything else.
1 Like
I’m not even sure the bar has to be that high. I imagine there are industrial uses for salts or just things like salting roads in the winter. But whatever is done with it is likely to ultimately be more expensive than just pitching it back in the ocean (which is to be avoided).
Grunch, but this is a good piece:
A good explainer including a very interesting new tech in Saudi Arabia
Discharges can have significant effects on salinity levels locally, which can definitely do significant damage in those areas. Similar issue happens with discharges from Lake Okeechobee messing with the salinity of the Caloosahtachee River Estuary and St Lucie River Estuary.
1 Like
paging @Danspartan
the issue with this kind of thing is always, always, always lack of scalability which ruins the whole thing.
Either that or, given that it’s bacteria, we’ll manage to let it mutate into something that kills all of us. Silver lining, though, is that resolves climate change!
the single most massive impact you can have on carbon footprint is by not having any children - but I don’t hear this brought up ever, if at all. At some point in the near-ish we will have to consider reigning in our population a bit. I’m not sure what the answer is, but to me it doesn’t seem likely we can just keep shitting out kids at the current rate (although I am aware birth rates are on the downtrend overall)
if i ever get the father urge I plan on adopting
1 Like
I’m not on FB or Twitter and this is cliche. (The point about not having kids).
This is a perfect example of speaking authoritatively on a matter for no reason at all. Your “well ackshually” is already written in the tweet that he quoted.
Should everyone just give the fuck up?
Scalability is an issue. Look at the massive amount of ethanol fermentation required to replace 10% of the gasoline in our cars.
Fermentation is water intensive, so first you have the water to grow the plant matter (likely corn or cane/beet sugar) then the water for fermentation which is going to be multiple gallons of water per gallon of fuel.
Also the plant material being starch/sugar you are about 1/2 oxidized. You have to invest in reducing the COHs in sugar to CH2s in alkanes (most fuels). That requires either loss of some sugar to do the reduction or adding a source of hydrogen.
Anything from lignocellose (not easy sugar like sucrose or glucose from starch) is not ready for prime time. It’s still too difficult and the enzyme costs to break down cellulose too costly.
Typically alkanes have a theoretical yield of sugar of about 33%. Assume it’s 3lbs of sugar per pound of fuel and a gallon of fuel is 6.6 lbs so round that to 20 pounds of sugar per gallon. A great deal on sugar currently is probably 20c/lb so let’s say 15c/lb to be optimistic. You are at $3/gallon and you haven’t paid for any capital, any energy, any of the chemicals, maybe you can get $5/gallon. Maybe. The second oil drops it doesn’t make any sense at all. And in reality people are getting lower yields so 4 to 5 lbs of sugar per pound of fuel. Easy to get to $7/ gallon just for the sugar.
IMO, commodity scale fermentation is better used to make partially oxygenated molecules (like lactic acid which is the biggest thing I’ve done in my career). That can be turned into a biodegradable plastic.
Otherwise fermentation is better to make specialty chemicals that go for a few to 10s of dollars per pound.
Don’t get me wrong, the bio routes are going to be needed to replace things made from a barrel of oil. It’s just not far enough down the cost curve yet.
4 Likes
my mistake, I swear i get in arguments about this all the time lately - I’m still told to reduce my beef intake, watch my driving habits, and to reuse plastic bags. none of that’s bad, but I can eat a diet of 300% beef, coal roll all day, and use 50,000 bags a day and still not come close to the impact of having a single child, so I alwyas get a bit confused.
if that’s mainstream now, good, people need to stop having kids
This disregards all the positive impacts that a child could provide. I’ve never bought into this notion.
2 Likes
Women should select shorter guys to have sex with so they produce smaller children with less of a carbon footprint than taller children.
3 Likes