A Battery Which Desalinates Water In Charging and Discharging.

[NNadir]

The paper I'll discuss in this post is this one: A Desalination Battery Combining Cu3(Fe(CN)6)2 as a Na-Storage Electrode and Bi as a Cl-Storage Electrode Enabling Membrane-Free Desalination (Do-Hwan Nam , Margaret A. Lumley, and Kyoung-Shin Choi,* Chem. Mater., 2019, 31 (4), pp 1460–1468)

The graphic in the abstract also appears in the paper's text:



In the text the caption reads as follows:

Figure 7. Scheme showing the operation of the CuHCF/Bi desalination battery; the desalination process is equivalent to discharging and the salination process is equivalent to charging.

According to a lecture I attended last weekend, sea level rise has been measured as rising at the fastest rate ever observed in recorded history, said history extending back to the 18th century in the form of tidal gauges.

Science on Saturday: Managing Coastal Risk in an Age of Sea-level Rise



I have often wondered about the effect of the release of fossil water, such as the water being mined from the stressed Ogallala Aquifer in the Central United States to irrigate corn and wheat crops, on sea level rise.

According to the speaker, Dr. Robert Kopp , the proportion of sea level rise owing to the mining of fossil water represents about 10%.

It follows, in a speculative if not practical sense, that recharging these fossil reservoirs with fresh water produced by desalination might serve to help drain rising seas, at least in the "percent terms" that the people who have cheered the failed policy of betting the planetary atmosphere on solar and wind energy so love.

Of course the requirement for doing this, for desalinating seawater and putting in in fossil aquifers involves huge amounts of energy since desalination is an energy intensive process, both in the sense of desalination itself and in the sense of shipping the water to the aquifers themselves.

A battery is a device that wastes energy, as I often remind those silly - but effectively dangerous inasmuch as humanity has lost the bet they made - people who bet the planetary atmosphere on solar and wind energy. They think a metal based band aid will fix the useless and trivial solar and wind industries biggest problem, at least in their minds, its intermittent nature. This is a bit of a distraction. The biggest problem of the trivial solar and wind industry is that it has not worked, is not working and will not work to address climate change. All of the solar and wind energy provided each year as of 2019, after decades of wild cheering produces a fraction over 10 exajoules - 10.63 exajoules to be exact - of the nearly 585 exajoules - 584.95 exajoules to be exact - humanity was consuming as of the last full report, referring to 2017. In this century energy demand rose by 163.84 exajoules.

2018 Edition of the World Energy Outlook Table 1.1 Page 38 (I have converted MTOE in the original table to the SI unit exajoules in this text.)

I'm sorry to kick over the milk from this much worshiped sacred cow, but our ethical responsibility to all future generations must be the statement that "reality matters."

The fact that a battery wastes energy is a consequence of the 2nd law of thermodynamics, which is a law of physics. Physics doesn't care about people's energy fantasies; the laws of physics are not subject to repeal by any legislature or change because of any "New Deal" or any linguistic exercise attempting to define what is and is not "green."

Nevertheless, the battery described in this paper is interesting because it does something that I believe, despite Jevon's Paradox, which it increases the efficiency of energy use, inasmuch as it captures energy that would otherwise be wasted, not all of it course - the 2nd law prevents that - but more of it.

From the introductory text of the paper:

Lack of access to fresh water is one of the most serious issues currently facing our society,1?4 and seawater desalination is considered the most feasible approach to produce an adequate supply of fresh water.5?8 Currently, thermal distillation and reverse osmosis (RO) are the two most established seawater desalination methods.6?10 While RO is less energy intensive than thermal distillation, it still requires significant electrical energy input for the operation of high-pressure pumps. In addition, processes related to the prevention of membrane fouling (i.e., pre-treatments and post-treatments of water) keep the cost of seawater RO high.8?12

Recently, various electrochemical desalination methods have been reported.13?34 The operating principles of these electrochemical desalination methods are fundamentally different from those of RO and thus provide diverse opportunities to advance desalination technologies. Among these systems, desalination batteries are particularly attractive because they couple desalination with energy storage.29?34 Like other conventional batteries (e.g., Li-ion batteries), desalination batteries store and release energy during the charging and discharging processes. However, through combination of a Na storage electrode and a Cl-storage electrode, the energy storage and release are coupled with the removal and release of Na+ and Cl?. Because the energy consumed during the charging process is at least partially recovered during the discharging process, desalination batteries can potentially achieve costefficient desalination with a much lower energy requirement than conventional desalination systems. Furthermore, as Na+ and Cl? are stored in the bulk of the Na-storage and Cl-storage electrodes, not just in the electrical double layer of the electrodes as in the case of capacitive deionization, a high capacity for salt removal can be achieved.29?33 As a result, desalination batteries may be used for seawater desalination as well as brackish water desalination. Another distinct advantage of desalination batteries is the possibility to achieve membranefree desalination.

Previous efforts, according to the paper, to make a chloride storing electrode involved the use of insoluble silver chloride, but was considered impractical owing to the cost of silver and the poor electrical conductivity of AgCl. In a previous paper, the authors described a new kind of storage electrode based on bismuth, mostly known to consumers as a constituent the pink anti-diarrheal OTC medication PeptoBismol, and to nuclear engineers as a constituent of the LBE eutectic metal used in certain types of fast nuclear reactors.

In an earlier paper, the authors' group described the discovery of this electrode:

Bismuth as a New Chloride-Storage Electrode Enabling the Construction of a Practical High Capacity Desalination Battery (Do-Hwan Nam and Kyoung-Shin Choi, J. Am. Chem. Soc., 2017, 139 (32), pp 11055–11063)

This new type of electrode during charging undergoes the following electrochemically driven reaction:



In this case the chloride ion is oxidized to the hypochlorite ion which is the common constituent of bleach, water purification chemicals and the "chlorine" in swimming pools. However it is stored in the electrode as the insoluble bismuth salt.

The update that this paper describes involves the other electrode, which is a copper ferricyanide based electrode.

If the presence of cyanide worries you in a water desalination electrode, don't worry, be happy. Ferricyanide is very insoluble, and a form of it, known as "Prussian Blue" is actually used as an antidote to heavy metal poisoning given its strong ability to complex monovalent species, notably as an antidote should you happen to eat the rat poison thallium or Cs-137, the radioactive fission product. (People have a kind of fetish about the possibility of being exposed to Cs-137, even though the isotope has been ubiquitous since the era of open air nuclear testing; they are less concerned with air pollutants, even though air pollutants kill seven million people every year and cesium-137, um, doesn't. Go figure.) People deliberately eat ferricyanides.

Another advance the authors have made involves the physical form of the bismuth electrode; it is described herein as a "foam."

Similarly the copper ferricyanide electrode is also a foam, as shown in the following graphic from the paper:



The caption:

Figure 1. (a) XRD pattern and (b, c) SEM images of as-synthesized Cu3[Fe(CN)6]2·nH2O (CuHCF) powder.

The cupric ferricyanide compound is referred to as "CuHCF" throughout the rest of the paper. (I'm not sure why.)

The overall structure of this system is also shown:



The caption:

Figure 2. Unit cell of a Prussian blue analogue with an ABX3 perovskite-type structure, where B sites are occupied by alternating Cu(II) and Fe(III) ions and X sites are occupied by CN groups. The degree of occupancy of the A site varies depending on the Cu(II)/ Fe(III) ratio and the Fe(II)/Fe(III) ratio.

This structure is, more or less, best described as the perovskite structure. Lead based perovskites, in particular those containing cesium, have generated lots and lots and lots of papers connected with the scheme of making solar energy work, which, if you actually take efforts to address climate change seriously, as opposed to having an entirely dogmatic fondness for solar energy, has not worked in any meaningful sense, is not working in any meaningful sense and will not work in any meaningful sense. Believing that solar electricity is a path to addressing climate change is no different, at least in my book, then outright climate change denial. The scheme to make cesium lead based perovskite solar cells is even worse than the distribution of cadmium based solar cells, because lead is a very toxic metal and distributing it widely is a very bad idea. (Prussian Blue will not effectively treat lead poisoning.)

I wish people would think and if they can't do that, at least observe.

Anyway...

The redox element in the copper ferricyanide electrode is the iron, which is reduced from the ferric, (Fe(III)) ion to the ferrous (Fe(II)) ion and back again in the charge/discharge cycle:



Here is a graphic demonstrating the performance of the system as a battery:



The caption:

Figure 3. (a) Potential?capacity plots and (b) cycle performance of the CuHCF electrode tested at a current density of 60 mA g?1 in an acidic 0.6 M NaCl solution (pH 1.2). (c) Potential?capacity plots and (d) cycle performance of the CuHCF electrode tested at a current density of 60 mA g?1 in a neutral 0.6 M NaCl solution (pH 6.2).

From this diagram it's clear that the performance of the system in terms of cycling is a little less effective in neutral solution than in acid. This could be a real problem for the water quality the system puts out, but let's continue anyway.

This problem is demonstrated by looking at the color aspect of the desalinated water.



The caption:

Figure 4. (a) Photographs showing the colors of the solutions after the cycling tests and chemical stability tests. The yellow color is due to the dissolution of Fe(CN)6 3?. XRD patterns of the CuHCF electrode after 40 cycles of sodiation/desodiation in (b) an acidic 0.6 M NaCl solution and (c) a neutral 0.6 M NaCl solution. The XRD patterns of Cu3[Fe(CN)6]2·nH2O and Cu2Cl(OH)3 are shown for reference.

The problem seems to lie with the nature of the CuHCF electrode.

The authors investigate in some detail how it behaves over a range of pH values:

To elucidate the cause of the instability of CuHCF, we first examined the solubility of CuHCF in a neutral 0.6 M NaCl solution but found no change in composition even after 1 week of immersion. However, when we increased the pH of the solution to 11, we visually observed the dissolution of Fe(CN)6 3? from CuHCF (Figure 4a and Figure S1) and saw the formation of Cu2Cl(OH)3 by XRD. Indeed, CuHCF is known to decompose to Na3Fe(CN)6 and CuO in the presence of NaOH through the following reaction:



In the presence of Cl?, however, Cu2Cl(OH)3, rather than CuO, will form as one of the decomposition products (eq 4). We confirmed the thermodynamic feasibility of the formation of Cu2Cl(OH)3 in 0.6 M NaCl solution by constructing a Pourbaix diagram for Cu in an aqueous solution containing 0.6 M Cl? (Figure S2). Based on these results, the degradation of CuHCF accompanied by the dissolution of Fe(CN)6 3? that occurred during the cycling test in neutral saline water can be expressed as follows:




After elucidating that the instability of CuHCF was related to the reaction between CuHCF and OH?, we realized that the instability of CuHCF during the cycling test in neutral solution was caused by OH? generated from the Pt CE used in the three-electrode cell. The major reaction that can occur at the Pt CE in an aqueous solution during desodiation of the CuHCF electrode is water reduction (eq 5), which generates OH?.



Because the CuHCF and Pt electrodes were kept very close (<0.5 cm) to minimize the IR drop from the solution, the local pH experienced by the CuHCF electrode could have increased significantly during water reduction at the Pt CE, resulting in the formation of Cu2Cl(OH)3 and dissolution of Fe(CN)6 3?. This also means that the capacity fading of the CuHCF electrode observed during the half-cell test in a neutral solution is not an intrinsic limitation of operating CuHCF in a neutral solution. Rather, it is a problem that arises from the alkaline pH generated from water reduction by the Pt CE that will not be used in a real device.

That's good news, I guess, but perhaps at the end of this questionable post - questionable since it goes against the popular perception and we all know that what is popular is always right, right? - it might be useful to question what a "real device" is or might be.

The preparation of the Bi electrode is not described in detail in the paper, but the reference containing the detailed description is given; it is the same one referenced above by the authors in the same group.

This schematic gives the general idea, however, and the result is shown in SEM:




The caption:

Figure 5. (a) Schematic illustration of the deposition of a Bi foam electrode using in situ generated H2 bubbles as a template and SEM images of a Bi foam electrode showing the (b) foam structure and (c) nanocrystalline Bi forming the foam wall.

And now the fun part, reflecting the thermodynamics to which I refer whenever the "magic" of batteries is evoked to show how so called "renewable energy" "could" work, except it hasn't worked, isn't working and won't work. We've gone up 23 ppm in carbon dioxide measurements in the last 10 years at the Mauna Loa atmospheric carbon dioxide observatory, this while sinking trillions of dollars into solar and wind.

The thermodynamics, graphically displayed:



The caption:

Figure 6. Potential–capacity plots for the CuHCF and Bi electrodes measured vs Ag/AgCl at a rate of ±1 mA cm–2 during (a) the desalination process in a neutral 0.6 M NaCl solution (pH 6.2), (b) the salination process in a neutral 0.6 M NaCl solution (pH 6.2), and (c) the salination process in 65 mM HCl (pH 1.2). Corresponding cell voltage–capacity plots (d) during discharging (desalination) in 0.6 M NaCl (pH 6.2) and charging (salination) in 0.6 M NaCl (pH 6.2) and (e) during discharging (desalination) in 0.6 M NaCl (pH 6.2) and charging (salination) in 65 mM HCl (pH 1.

Again, a battery is a device that wastes energy, as the preceding diagram for this battery clearly shows.

The Coulombic efficiency, or Faradaic efficiency, is shown in the final graphic to be included in this post:



The caption:

Figure 8. Cycling test of the CuHCF/Bi cell for desalination/salination. The discharging process (desalination) was performed in0.6 M NaCl (pH 6.2), and the charging process (salination) was performed in 65 mM HCl (pH 1.2).

Faradaic efficiency is a different matter than thermodynamic efficiency; the faradaic efficiency may be thought of as a loss to chemical side reactions that degrade the battery over time. By contract thermodynamic efficiency involves a number of other factors such as the internal resistance of a battery, which itself is a function of the concentration - or more precisely the activity - of ions which conduct the current within the battery. In this case, the ions are salts, and a reduction of the concentration of salts, which the battery is designed to accomplish, raises the internal resistance, and therefore the thermodyanmic efficiency is reduced. This is why the battery works better in an acid solution than in a neutral solution. The practical import of this would mean that the system would probably not be very viable to generate tap water, although it might prove acceptable for use to make agricultural water, particularly in the case where the acid is neutralized with ammonia, and then subject to ion exchange whereby the chloride is replaced by nitrate, or, if it works, where nitric acid is used in lieu of hydrochloric - although I'm not personally familiar with the chemical stability of bismuth metal in nitric acid as opposed to hydrochloric acid.

Despite the high “columbic efficiency” the authors make the point that the batteries do have a long term cycling problem, a materials science problem involving repeated expansion and contraction. (This is a feature of many situations involving batteries: They are thought of as electrochemical devices, but they most assuredly have a mechanical feature, which is sometimes utilized to measure their remaining capacity during discharge.) In describing the problem, they discuss an approach to addressing it:

We note that the slight capacity fading observed during the cycling test is not due to the decomposition of CuHCF, which was easy to confirm as the solution did not change color, unlike what was observed during the half-cell test. We believe that this was caused by the pulverization of the Bi electrode due to the volume change involved during the conversion between Bi and BiOCl (158%). There are several effective strategies that can be used to improve the cycle performance of Bi, which include the addition of a carbon or polymer coating on Bi or making composites of Bi with Cl-inactive materials to buffer the volume change of Bi during chlorination/dechlorination. These strategies have been proven to work for the stabilization of other electrodes that suffer from this pulverization problem.45,46

Now we need to turn to the issue of what this paper implies. Very often, particularly in blogging kinds of situations, people look at some small laboratory scale results to assume that they are ready for prime time, to immediate scale up to industrial scale. This is almost never the case; indeed, it's extremely rare for a laboratory result to be transferred to an industrial scale. I've known many tens of thousands of scientists in my career, and can count on the fingers of one hand those I met who experienced such a thing; I am one such person, not because I'm good, but because I'm lucky to have participated in a discovery and had the opportunity to work in a place where the need for it appeared.

As impressed as I am with this very interesting paper; I'm not sure at the end of the day it will mean very much at all.

Batteries generate lots of enthusiasm among those people who have bet trillions of dollars, and worse, the planetary atmosphere, on the idea that solar and wind energy will save the day, even though solar and wind energy won't do any such thing. These people claim, in defiance of data, that a "problem" with so called "renewable energy" is that it's intermittent, and thus if we had batteries or hydrogen, or some other such thing, everything would be wonderful and dangerous fossil fuels would magically disappear. This is nonsense. After more than half a century of world wide cheering - beginning with the invention of the solar cell in 1954 (there are Bell Labs Magazine ads from the early 50's available on the internet showing this history) - all the world's tidal, geothermal, solar and wind energy combined produced as of 2017, 10.83 exajoules of energy, increasing at by 1.21 exajoules in a year that world energy demand increased by 8.88 exajoules. By contrast the use of dangerous natural gas grew in 2017 by 4.19 exajoules, and petroleum by 1.97 exajoules. (Coal fell by 0.21 exajoules, trivial in a century where overall, it grew by more than 60 exajoules (60.25 to be exact) - so the often stated nonsense that it is falling because of so call "renewable energy" is a Trumpian scale lie.) So called “renewable energy” other than biomass and hydroelectricity – and we’re running out of rivers to completely destroy – produces less than 2% of the world energy supply, and now we want to start wasting the trivial quantities there are. Even adding the two forms of energy also described as "renewable energy," biomass and hydroelectricity, so called renewable energy produces less than 15% of the world's energy supply. The reason that so called “renewable energy” isn’t working, hasn’t worked and won’t work is physics, specifically the extremely low energy to mass ratio.

Even if the solar and wind industries were as magic as these gamblers hoped they would be - whether or not we engage in the "gambler's fallacy" and throw even more good money after bad money for this unworkable scheme, it’s clear that humanity as a whole has already lost the bet - it is unlikely that these desalination batteries would really produce significant amounts of water, since for one thing, it's not likely that charging and discharging even on a grid scale, would produce all that much water. Secondly it's not clear that there is enough bismuth available for isolation to produce hundreds of millions of these devices, which is what obviously is required.

Bismuth supplies are not generally considered to threatened, but they are of long term concern; said concern being tied to current demand. If the demand rises however, a different calculation may be obtained. One possible way to increase demand would be of course to make millions upon millions of desalination batteries. (This won't happen; it's a thought experiment.)

A brief point: I am often - appropriately, I think - called out on my hypocrisy; for one example I drive a car even as I call for an end to the car CULTure.

In the case of bismuth supplies, someone might note that I favor high temperature nuclear breeder reactors minus the traditional liquid sodium coolant, and that I've expressed admiration for LBE cooled reactors wherein "LBE" refers to "lead bismuth eutectic" alloys. However, if we drop the bismuth and stick with pure lead, I also note than in a neutron flux lead would be transmuted into less toxic bismuth, creating such a eutectic in a reactor that starts out cooled by pure molten lead. (No matter: No one cares what I think about nuclear reactors anyway.) It is possible to synthetically make bismuth from lead, although in truth, the high energy density of nuclear power means that the amounts of bismuth that could be so synthesized is very small; this high energy density also makes nuclear power environmentally superior to all other forms of energy even as it presents some engineering problems. In any case, the same energy density means that the requirement for bismuth is very much smaller in the nuclear case than it would be in the battery case.

The issue is not really about bismuth as it is about critical thinking.

Not long ago in this space, there was a post entitled - excuse me if I paraphrase - "Scientists discover a way to make carbon dioxide back into coal."

It was linked to a university press release about the wonderful generic scientists who accomplished this wonderful feat. I personally was a little surprised that this was a big announcement. We have known for over a century how to accomplish this feat: It's called the "Boudouard reaction" and its discoverer, Octave Boudouard died in 1923, twenty-three years after discovering the reaction that bears his name.

The breathless post contained some commentary, including some sarcastic remarks from me (which happily resulted in no response), in which the original poster said that this miracle "could" maybe, possibly, after a fashion, be performed using solar energy (which he or she declared to be "the best option" or maybe we could wait around for those magic nuclear fusion reactors to appear at a commercial scale.

Now here's the terrible thing: Curious at why this recapitulation of something the Boudouard reaction has been known to do for over a century, I opened the link to the news release.

Here's the news release in question, from scientists in that coal burning hellhole in Australia: Climate rewind: Scientists turn carbon dioxide back into coal.

I never read any of these news releases picked up by the popular press and reported elsewhere without investing some critical thinking. If the issue strikes me as odd - and this one does since I think about the Boudouard reaction all the time - I'll look for the original source and look into it to understand what, precisely, the big deal is.

The news release refers to a paper published in Nature Communications. I am very fortunate, because I pretty much, with some minor exceptions, have access to all the world's primary scientific literature. I fully realize that many people are not so privileged, but in this case, such access is not necessary, because the paper is open sourced; anyone with access to the internet can read it.

Here it is: Room temperature CO2 reduction to solid carbon species on liquid metals featuring atomically thin ceria interfaces (Dorna Esrafilzadeh et al, Nature Communications Volume 10, Article number: 865 (2019))

Here's a brief description from the paper of the experiment:

Synthesis of different weight fractions of metallic cerium (0.5, 1.0 and 3.0?wt%) into liquid galinstan was performed using a mechanical alloying approach (see Methods). Cerium containing LM was created, since cerium oxides are known to reduce CO2 to CO via the Ce3+–Ce4+ cycle4,5. Cerium’s solubility in liquid gallium and its alloys is expected to be between 0.1 and 0.5?wt%, while Ce2O3 is expected to dominate the LM surface, as a 2D layer, under ambient atmospheric conditions due to the high reactivity of cerium when compared to the constituents of galinstan, and the known oxidation mechanism of metallic cerium that leads to the initial formation Ce2O3 at the metal–air interface15,21,22.

The bold is mine.

Here, also from the paper, are the constituents of "galistan":

Common low-melting point gallium alloys, such as the eutectic mixture of Ga, In and Sn, referred to herein as galinstan...

Here is the periodic table of "endangered elements," elements whose supply generate concern among chemical and economic professionals:



Of the three elements in "Gallistan" two, indium and gallium are identified as facing "serious threats," the third, tin, faces long term supply issues.

(I have discussed the availability of cerium elsewhere in this space: Cerium Requirements to Split One Billion Tons of Carbon Dioxide, the Nuclear v Solar Thermal cases. )

As of last year, anthropomorphic activities are estimated to have resulted in the release of 41.5 +/- 0.3 billion tons of carbon dioxide: Global Carbon Budget 2018

The same publication (see the internal spreadsheets) estimates that since 1750, human activities (including deforestation) have resulted in 430 billion tons of carbon (+/- 20 billion tons), which equates roughly to 1.5 trillion tons of carbon dioxide.

We are never going to have enough gallium based alloys to significantly reduce carbon dioxide.

As for "solar being the best way," in 2017, coal burning was responsible for 157 exajoules of energy, solar and wind combined less than 11. If one can't think critically about what these numbers imply, one can't think critically at all.

The time for credulous wishful thinking is done.

Critical thinking is best done when one looks at sources; but one can also do it on the fly - to a first approximation - simply by inspection.

As for desalination, for many reasons, including but not limited to sea levels, we need to do it. Like removal of carbon dioxide from the atmosphere, it is an energy intensive process and a huge engineering challenge. My own expectation is that the best route to it is one that has never been industrialized, the use of the fact that salts are insoluble in supercritical water. I note that an added benefit of this approach will be the supercritical oxidation of biomass in seawater, as well as the serious pollutants represented by microplastics in seawater. In the right array, one can imagine many types of systems whereby the energy can be recovered, water can be recovered, carbon dioxide can be captured and valuable elements in seawater, notably uranium, can be captured.

That's all for a later long winded rant into the void.

I wish you a pleasant Saturday evening and a wonderful Sunday.

[mitch96]

1. Questions........

Maybe I missed it and is this water potable? Can you use it on crops? If not how much energy is needed to convert to drinking water. ? Just curious..
m

[NNadir]

2. I don't think, in this particular laboratory scale device, the water would be potable.

No battery can really run without ions, and here the ion strength is provided more or less by acid, something I allude to in the text.

If one is able to use nitric acid rather than hydrochloric, or is able to conduct an anion exchange nitrate for chloride, it might be suitable for agriculture as "fertilized water."

However it is difficult to imagine this device working on a scale making it practicable for irrigating crops.

Thanks for a good question.

[mitch96]

5. "difficult to imagine this device working for irrigating crops."

So the first thing that pops into my mind is, so what's the point other than just a nice experiment.. Then again how many seemingly unrelated experiments lead to breakthroughs that helped mankind... Reminds me of that TV program in the late '70 with James Burke,
Connections... https://en.wikipedia.org/wiki/Connections_(TV_series)
A facinating program showing the linkage of discoveries from the past that effect our daily world today.. I loved that show.. https://tinyurl.com/y5fkdk7y

&list=PL-teo99ENSypJDyeXmEpLOxWMB9UVPbOS&index=7

[eppur_se_muova]

3. Well, let's remember "proper" nomenclature -- hexacyanoferrate(III) for the common 'ferricyanide'

... and you have CuHCF as a 'reasonable' abbreviation.

Interesting concept, but I agree about the impracticality of using a scarce element for large-scale operations. I just hope some analogous behavior in something less exotic can be found which enables a more practical process. The Periodic Table is finite, however.

Give the guy kudos for seeing the *potential* implications of a fairly obscure observation. Maybe it will inspire more practical approaches from others who hadn't thought about such possibilities as much.

I've always tried to think of potential approaches to energy storage, alternative fuels, etc., but desalination is one problem for which I've never had an inkling of any idea of how to go about it that wouldn't consume great gobs of energy. My grasp of thermodynamics at a really technical level is just not there. Glad there are others who seem to have a handle on it, and hope they succeed.

[NNadir]

6. Thanks. I seemed to have missed that...

...but on reflection it makes perfect sense. (I'm getting old or lazy or both.) These days, whenever I see a "C" in an electrode's name, I assume it's some kind of carbon electrode.

On another score, you've identified the biggest problem with climate change which is, essentially, we pretty much have to have as much energy - actually more - to remove this stuff as obtained from burning it.

I have read recently that the estimated amount of carbon released by humanity since 1750, from both combustion and land use changes is on the order of 420 billion tons, which translates to 1.5 trillion tons of carbon dioxide.

Earth Syst. Sci. Data, 10, 2141-2194, 2018 (Open sourced.)

The free energy of formation of carbon dioxide is 394.39 kJ/mol.

This implies that even if we had all of the carbon dioxide isolated - we obviously don't - we would require about 50,000 exajoules to reduce it to carbon. This is the equivalent of almost a century's worth of the total energy demand for the entire planet for all purposes.

Then there's addressing the entropy of mixing.

I often state that not only have we dumped carbon dioxide on future generations, but we have also dumped entropy on them as well. There is a cool little book that has not gotten all that much attention on entropy for the other elements in the periodic table.

Thanatia: The Destiny of the Earth's Mineral Resources: A Thermodynamic Cradle-to-Cradle Assessment

Not only are we leaving future generations with depleted carbon dioxide, but we have also mined most of the world's best ore's, meaning to do what so so glibly insist they will do when we offer this cynical "By 2050" or "By 2100" garbage, they must do this with degraded resources.

Sobering, I think.

[eppur_se_muova]

8. Interesting-looking book, and knowing that "thanatos" means "death" makes the title ...

... extra-worrisome.

Noted for when I can afford new books again.

[NNadir]

9. They don't get around to firmly explaining their title to chapter 10.

They write:

This chapter provides a very important ingredient for any exergy assessment, the establishment of a coherent baseline for the evaluation of the mineral endowment on Earth. This is represented by the theoretical planetary state Thanatia. This in turn is quantitatively assessed with the Crepuscular Earth Model, which is composed of a heightened CO2 atmosphere, saline hydrosphere and resource depleted crust. Additionally, the difference between the concept of Thanatia and Reference Environment (R.E.) is explained…

…The hypothetical Earth alluded to here is Thanatia and as indicated by the Greek "??????", represents death. In fact it is the embodiment of non-violent death. The authors use the name to describe the possible state of the Earth when all commercially exploitable resources have been consumed and dispersed. Moreover, Thanatia, as both a name and a concept, constitutes the starting point for assessing the loss of mineral endowment on Earth. The model behind Thanatia is the "Crepuscular Earth" and has been developed with current geochemical and geological information on the atmosphere, hydrosphere and crust (see Sec. 10.3).

The part of the book that fits very well with my own thinking on this score, although it doesn't consider so called "renewable energy" as useless as I do, is this:

The authors believe strongly that the world needs more sustainable energy than the mere 7 to 15% that many forecasts are predicting for the next generation. Renewable energies could and should help plug the gap but cannot and should not be considered at least in the short term as the complete solution. This is because it is not a matter of just deploying more of them. To that effect, Heinberg (2009) defines four conditions for a primary energy source to be competitive in the future:

• It should provide a substantial quantity of energy and its contribution to countries should not be marginal.

• The energy provided should be at least ten times greater than the required energy to place it in the market from the cradle.

• It should be acceptable from a social, geopolitical and environmental point of view, including the effects on climate

• It should be renewable.

Garda-Olivares et al. (2012) add a fifth point:

• Energy exploitation and use (including renewables) should not depend on scarce materials.

It is in fact this last point which is the most forgotten issue in practically all discourses in favour of renewable energies. As apart from the need for further research and development, renewable energy infrastructure is less densely packed than fossil fuels and thus requires a much larger (quantity of land and critical raw materials for successful deployment.

In consideration of the "fifth point," is why I question that what we call (rather sloppily I think), "renewable energy" is, in fact, "renewable energy."

Future generations are going to need to mine our waste; it's not fair; it's not justice; but it is reality. I feel very strongly that the key to mining dilute sources is energy, and I would add a sixth point: "In order to be environmentally sustainable, a form of energy must exist in a high energy to mass ratio.

[StevieM]

4. On an unrelated topic, I am curious as to who you are leaning towards in the 2020 primaries.

It seems like you might be most interested in Jay Inslee or Cory Booker, both of whom have indicated some support for nuclear power in the past.

[NNadir]

7. Actually, I haven't spent all that much time thinking about it. I'm totally irrelevant...

...to the process of selecting a nominee, since I live in New Jersey, where the primary is in early June; the time, usually, that the nominee has been selected.

I heard Inslee's announcement on the radio, and it pissed me off, because while he was talking about climate change, it was all about wind and solar, blah, blah, blah.

I actually got into an argument on this subject elsewhere here, with some supporter of his - one hopes he or she was a kid with a poor education - telling me how the solar industry was "just getting started." I pointed out that it was "just getting started" in the 1950's, and that it now a trillion dollar industry - useless, but still generating a lot of money changing.

If Inslee becomes President and doesn't drop this "solar will save us" and "wind will save us" nonsense, he will fail to do anything to address climate change. Solar and wind haven't worked, they aren't working, and they won't work.

Corey Booker is my Senator; but I don't know all that much about him to be honest. During the Senate Primary he ran against Rush Holt, who I believe would have been a great Senator. I actually engaged Dr. Holt several times on nuclear energy. He was decent about it, but guarded. He's ex-PPPL, and although I love living near PPPL and frequently attend lectures there, they remind me of Upton Sinclair's remark that "It is difficult to get a man to understand something when his salary depends on him not understanding it."

This, of course, is the crux of the climate change issue.

Because PPPL wants money to build a fusion reactor, they have to carry on about so called "nuclear waste" and "nuclear war." The problem with fusion energy though, is that it's not here. The theory is wonderful, but it's not here. It's difficult to imagine that even if a working power generating fusion reactor were built, it would still take 30 years before they became a significant source of energy. We're talking in terms of close to a century. At 2.3 ppm of CO2 per year, that puts up out at close to 600 ppm.

Let me say this:

In 2008, I opposed Obama's nomination - again with no consequence because he was clearly going to be the nominee by June of 2008 - because an element of his stated energy policy was coal to oil (Fischer-Tropsch) work. I supported Ms. Clinton. As President, however, he was quite a bit better. He and Steven Chu worked to restart nuclear power plant construction in this country; they didn't achieve very much, but they tried. I believe the two reactors in South Carolina will eventually come on line.

I personally believe that Barack Obama was the best President of my adult life, but even the best President may find it nearly impossible politically to do very much about the most dire crisis of our time.

I'm strictly ABT; hell, I'd even vote for Bernie Sanders if I had to. I hope I don't have to, but I would.

The problem is not with the candidates. The problem is with us. We insist that people tell us what we want to hear, even if what we want to hear has nothing to do with reality.

[StevieM]

10. Let me be clear as to why I asked about Inslee and Booker.

I certainly realize that you have deep concerns--to put it mildly--about the viability of solar and wind. But I had read that Inslee has expressed support for nuclear power in the past, and thought that maybe you were aware of that. Also, Cory Booker has expressed strong support for nuclear power.

I wasn't asking because I thought that Inslee's talk about renewable was appealing to you. And I wasn't asking about Booker because you are from his state. I had actually forgotten that you are from New Jersey, although I do now remember you telling me that.

Anyway, here is an article that talks a little about Booker, Inslee and Nuclear.

https://www.forbes.com/sites/jamesconca/2016/06/03/seattle-city-council-rejects-obamas-clean-energy-plan/#749039ab64db

[NNadir]

11. Thanks. That raises both in my estimation.

I still don't matter though.

I'll wait until my fellow Democrats in other states select the candidate, hope he or she wins, and hope that he or she will be bright enough - as Obama was - to get it.

[Massacure]

12. Out of curiosity, where does your opposition to wind power come from?

You've been a strong proponent for nuclear power on this site for more than 15 years (it's hard to believe it's been that long, I joined when I was still in high school!) and in hindsight at that time nuclear power was the most viable option to combat climate change. That being said, the amount of yearly energy (not power!) generated by wind is growing at a yearly clip roughly equal to that provided by three or so AP-1000 nuclear reactors (The ones being constructed at Vogtle). Wind's growth trend looks poised to continue accelerating.

Climate change is a problem. Nuclear power is a potential solution. What would it take for American industry to be capable of producing 3 or 6 or 12 reactors per year? If a presidential candidate came out with a plan tomorrow to double the annual rate of wind power in four years and to install an average of 10 Gwh per year of electrical storage (say vanadium redox) over that time, how would that compare in effort to a nuclear solution?

[NNadir]

13. I have lots of objections to wind power, but let me rank them.

1. It doesn't work. It has cost over 1 trillion dollars in the last ten years alone and has done nothing significant to address climate change.

2 It is intermittent, and despite all the nonsense about batteries, the reality is that it is backed up by dangerous natural gas. Thus it entrenches reliance on gas. If batteries on a huge scale become available, they will be an environmental disaster in their own right.

3. Wind turbines have a mean lifetime of less than 20 years. (For this, I have examined in detail, in several places on the internet, at several different times, the exhaustive database maintained by the Danish Energy Agency. I've published one or two of these types of posts here.) The people who are going to clean up this crap are babies now.

4. It has a very low energy to mass ratio, meaning that it requires huge amounts of steel (a coal dependent material), aluminum, (a petroleum dependent material), concrete (a major contributor to climate change), and lanthanide metals (natural gas and petroleum dependent, and, in most places, almost all in China, an environmentally disastrous mining profile). These mass requirements mean that the industry is not sustainable.

5. It plays hell on major avian ecosystems and species, particularly bats, but also birds and insects.

6. It turns precious ecosystems into industrial parks, requiring access by either trucks (on land) or diesel powered ships (at sea). I very much doubt that access roads are good for wild life, or that dumping concrete on benthic ecosystems are good for them.

I note that 15 years ago, I was a supporter of wind energy, but the more I looked at it - often being pushed to do so by the increasingly tortured arguments of anti-nukes - the more I questioned it. I changed my mind. As always, I was guided by what I read in the primary scientific literature.

I regret that it has become de rigueur for our party to support wind energy. I believe it's a mistake, a serious mistake. The best I can hope for is a candidate who, as Obama did, will recognize the environmental benefits of nuclear energy before it's too late, although truth be told, it is already too late.

I like to remind myself that John Muir founded the Sierra Club, one of its first actions being to oppose the huge renewable energy project known as the O'Shaughnessy (Hetch Hetchy) dam.

I'm not going to live all that much longer, but after I'm gone, I thoroughly expect my dissidence will be vindicated.

John Muir was right. There are some spaces to precious to destroy, and frankly that too is big draw back to wind, the space required.