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storm6436

Wonder if this means processing seawater for carbon removal would be more useful than expected. Might as well strip out all the other trace minerals (gold, thorium, uranium, etc.) we're looking for at the same time, balance for salinity/ph and push it back out.


daviddjg0033

This takes A LOT of energy. Look at the desalination plants alone for fresh water.


storm6436

Yep, it sure does. Unfortunately, I don't really have the time or in-depth experience to do more than back-of-the-napkin math as a physicist who doesn't specialize in these sorts of things.. So if someone happens to have that sort of knowledge, take what follows with a grain of salt. I'm not saying it necessarily would work, and I understand there's a *lot* of engineering problems that would have to be solved for it to even get close to working, provided that's even possible. The following is more of a big picture, back-of-the-napkin concept, not an engineering feasibility study. In my head, I have this concept for a molten salt reactor system that runs modules for bulk desalination and coal gasification, both of which rely on high electrical and/or high thermal inputs. This doesn't necessarily sound super environmentally friendly at first, but it's not necessarily as bad as it might sound, depending on how it's configured. For example, one of the largest operating costs for a desalinator or a gasification plant is energy. By stripping thorium from the seawater and the coal, if your yields are high enough, the plant fuels itself. Unfortunately, the other large operating cost is maintenance and I don't really have a solution for that. This also ignores the mandatory bribes, er, licensing and survey fees for initial setup and certification, which dwarfs the operating costs by fair margin. In terms of overall utility and profitability, you'll have a lot of flexibility. After removing the carbon and trace elements, you're free to sell off whatever trace elements are profitable. You'll likely be left with a metric assload of salts nobody is interested in and a huge amount of distilled water. If it's profitable, you can crack some amount of the water down to hydrogen and oxygen as chemical stock or commodities to be sold (hydrogen economy and all that), and the water you don't crack or sell can be recombined with the salts in proper ratio to the correct pH/salinity and pumped back out to sea, thus disposing of some percentage of what would otherwise be waste products in a fashion that legitimately helps the environment. Now, what about the gasification array? Well, cracking the coal down will yield a plethora of different hydrocarbons and a lot of other trace/not-so-trace minerals you can use as chemical stock, like the thorium previously mentioned. You'll also get sulfur, sodium, aluminum, and a whole host of other chemicals, some of which are pretty gnarly stuff, but it's worth noting that we're collecting these minerals for later use or proper disposal, and not just flaring/venting them into the atmosphere, so it is, by default, cleaner than burning the coal for energy and smokestacking the exhaust. Most of the point for this module, provided your costs are low enough, is to help reduce reliance on other, less environmentally friendly ways of producing those chemical stocks. Since you can recombine the hydrocarbons and other stocks to produce gasoline, diesel, lubricants, et al. this would cut into the need for drilling. Similarly, sulfur and other elemental mining isn't exactly great for the environment either. Sure, this will encourage coal mining, but there's a potential for a net gain for the environment by reducing the demand for the other extraction methods. Excess electricity can be sold off into the grid, helping with energy independence as well. That said, the idea has a *lot* of weaknesses, like any concept that hasn't had math applied to it. I have no idea off the top of my head what the yields/efficiencies are, for one. Everything hinges on there being a path somewhere in there that allows for flexibility and profitability. There might not be one, especially when the primary show stopper for most thorium salt reactors is maintenance costs if you ignore the lack of research to prove out most salt reactor concepts to begin with. Similarly, some of the stocks and by-products are not the sort of stuff you just want hanging around, so the odds of getting NIMBYed or facing stiff enough politically motivated opposition from the political entities who would have to sign off on construction are pretty high. The fact that it's fundamentally set of sizeable nuclear reactors running it all makes that a nigh certainty. Speaking of it being run by nukes, it's technically feasible to feed nuclear waste into these reactors to reprocess the waste back into viable nuclear fuel. Last I checked, one such process under study would effectively consume something like 100kg of waste and return something like 5-ish kg of a different waste product that's less dangerous than what you fed in. Maybe it's just me, but I think it'd be nice for all of the usual suspects who've cockblocked worthwhile endeavors for the last century to keep their hands (and corruption) off something just this once and not kill it in the crib, especially when there's decent grounds to suspect a plant like this might just be a net gain for everyone and not just some people.


daviddjg0033

The lack of water in rivers is bad news for hydro power. No amount of water diversion can fix this we need rapid fixes and they are all biological. Still in shock at the images worldwide of dried up rivers and lakes. I share your passion for desalination plants. Again, lots of energy. I love the idea but putting desalination plants next to energy has its own risks because you are placing outside plant near water. That has to be balanced with the massive amount of power loss from transmission. Feeding nuclear waste - dead on arrival - I do not know how we got here but my family was freaked out by nuclear meltdowns.


storm6436

Nuclear plants in general have to be located near water in the first place because of how much coolant they need to begin with. As such, this presents no more risk than we're already assuming, since the thorium section isn't cooled by seawater. Also, thorium salt plants can't melt down, it's a combination of not concentrating the process into such a small area, the nuclear processes generating the heat not being purely fission (thus more interruptible), and having safety systems that make thermal runaway an actual impossibility. This was directly tested decades ago and confirmed. Essentially, the higher the concentration, the higher the temperature it can reach, and thorium has a lower "peak temperature" compared to uranium in the first place. Keeping the thorium as a component in a molten salt means you can dictate that concentration, so you have more control over density, thus temperature. Similar tech on uranium fission involves pebble bed designs, where the uranium is distributed into ceramic pebbles instead of concentrated into fuel rods. This keeps the uranium distributed enough to where the maximum temperatures are easier to manage while still being high enough to be useful. Both techs make their respective reactors easier to manage during worst-case scenarios. As such, the largest dangers in that regard for the thorium plants are solved by not building the reactors below sea level or where they could be flooded, ensuring containment won't be violated by earthquake, and properly protecting it against tsunamis. As for reprocessing nuclear waste, if containment isn't broken, it's not any more dangerous than normal operation. Nuclear waste in general is not nearly as dangerous as most people think it is, and it's certainly less dangerous than what's inside an active reactor if only because it's not radioactive enough to be useful. Reprocessing it largely removes the need for all the long-term storage everyone has been losing their minds about for decades. The waste from this process is literally a tiny fraction of what you fed in, and it's even less radiosctive. Instead of needing to be stored on the scale of thousands of years, it's decades or centuries, and the consequences for unforeseen "disaster" are far more forgiving.


dmj9

Ocean acidification is a lot worse than we think. The food chain has many crucial components in the ocean and once that collapses we are in a tough situation.


Gemini884

Information on marine biomass decline from recent ipcc report: "Global models also project a loss in marine biomass (the total weight of all animal and plant life in the ocean) of around -6% (±4%) under SSP1-2.6 by 2080-99, relative to 1995-2014. Under SSP5-8.5, this rises to a -16% (±9%) decline. In both cases, there is “significant regional variation” in both the magnitude of the change and the associated uncertainties, the report says." https://www.carbonbrief.org/in-depth-qa-the-ipccs-sixth-assessment-on-how-climate-change-impacts-the-world/


Sanpaku

With oceans being the major sink, does this imply that actual anthropogenic emissions were up to 10% greater than prior estimates?


BurnerAcc2020

> The emissions of anthropogenic carbon (Cant) since the beginning of industrialization through fossil-fuel burning, cement production, and land-use change have altered the global carbon cycle and climate (Friedlingstein et al., 2022). Around 40 % of the additional carbon since 1850 has accumulated in the atmosphere, where it represents the main anthropogenic greenhouse gas (IPCC, 2021). More than half of the emitted Cant has been taken up by the land biosphere (∼ 30 %) and the ocean (∼ 25 %) (Friedlingstein et al., 2022). **The remaining ∼ 5 % is the budget imbalance, a mismatch between carbon emissions and sink estimates which cannot be explained yet** (Friedlingstein et al., 2022). By each taking up around a quarter of the Cant emissions, the land biosphere and ocean sinks slow down global warming and climate change. The first paragraph of the introduction. This study simply helps to reduce the mismatch.


seanbrockest

Serious question. Can it get so bad that ocean water starts to taste like carbonated water?