5 ms·
> ... Direct electrolysis of seawater rather than freshwater is highly significant, especially for the arid zones, since this technology not only stores clean e
by aazaa 7y ago
> ... Direct electrolysis of seawater rather than freshwater is highly significant, especially for the arid zones, since this technology not only stores clean energy, but also produces fresh drinking water from seawater. ...
There seems to be a step missing from that statement, specifically, oxidation of the electrolytically-generated H2 through combustion or in a fuel cell. Assuming that step, the water is pure, and there's no need for reverse osmosis which is itself quite energy-intensive.
This might be a key point to consider with industrial hydrogen generation rather than, say direct capture of solar energy in a battery. Direct capture yields energy only, whereas electrolysis of seawater yields potable drinking water and energy.
- mrspuratic 7y ago> ... electrolysis of seawater yields potable drinking water and energy. And salts, or typically, brine. That's a harder problem to solve (i.e. dispose of safely).
- vkou 7y agoWhy not just dump them right back in the ocean? Compared to the environmental shit-show of coal and oil extraction, wringing your hands over brine ending up in the ocean, seems entirely misdirected.
- klyrs 7y agoI'd have concerns about the effects of hypersalination on the ecology local to wherever you propose to dump this brine. This isn't "wringing hands," it's learned caution by somebody who doesn't believe in free lunch.
- vkou 7y agoSo put it on a tanker, and dump it out, bit by bit, in the middle of the ocean. This isn't a difficult problem to solve. It is absolutely wringing hands, compared to what we do with far more damaging products and byproducts of petroleum extraction.
- klyrs 7y agoAnd then what fraction of energy production are you spending on disposal, can you trust the folks disposing it [1], and will it properly circulate? Ocean currents and chemistry are extremely complex, and fisheries are an emergently fragile food source. I am, by no means, a fan of petroleum. But dismissing concerns about dumping chemical waste into the ocean as "hand wringing" is not a reasoned argument. [1] https://en.m.wikipedia.org/wiki/Toxic_waste_dumping_by_the_%27Ndrangheta https://en.m.wikipedia.org/wiki/Toxic_waste_dumping_by_the_%...
- AnimalMuppet 7y agoIt's not "chemical waste". It's what was already in the ocean. (Yes, I know, the same thing in concentrated form is different. But dilute it reasonably, and we're good. It's not like it's mercury or something.)
- klyrs 7y agoIndeed, a better characterization is "toxic waste." Mercury, uranium, etc., is present in ocean water and concentrating it isn't great, but it's the salt that kills.
- deleted 7y ago[deleted]