John Cuthber Posted September 24, 2021 Posted September 24, 2021 On 9/22/2021 at 6:25 PM, studiot said: How on earth can any mention of hydrogen be irrelevant in a thread all about hydrogen ? Grown-ups read all the words On 9/22/2021 at 1:46 PM, John Cuthber said: But you did raise the equally irrelevant liquid hydrogen.
exchemist Posted September 24, 2021 Posted September 24, 2021 On 9/22/2021 at 6:25 PM, studiot said: How on earth can any mention of hydrogen be irrelevant in a thread all about hydrogen ? Your post that I replied to certainly gave (me) the impression that you were offering facetious replies For your information I have already referred to the use of hydrogen for heavy vehicles, via fuel cell technology. You should be proud of your countrymen's achievements. https://www.jcb.com/en-gb/news/2020/07/jcb-leads-the-way-with-first-hydrogen-fuelled-excavator You can also read a calorific value of fuels table and see why hydrogen would be better than most other fuels, if we can make it work. So there is no call to be sarcastic about the matter. Finally in the link I gave in the post you apparently object so strongly to, they explain why it isnecessary to compress fuel gasses to liquid form for storage. A fact of life I though you already knew. He was referring to liquid hydrogen. Most transport fuel systems store hydrogen compressed as a gas. Storing it cryogenically as a liquid creates a lot of problems, maintaining the temperature, dealing with boil-off gas and so forth. And, as he mentions, the same is true of methane for transport fuel, which is stored as CNG not LNG.
Sensei Posted September 24, 2021 Posted September 24, 2021 On 9/22/2021 at 1:46 PM, John Cuthber said: That's why we have regulations. ...reminds me Volkswagen... 1
studiot Posted September 24, 2021 Posted September 24, 2021 2 hours ago, John Cuthber said: On 9/22/2021 at 6:25 PM, studiot said: How on earth can any mention of hydrogen be irrelevant in a thread all about hydrogen ? Grown-ups read all the words On 9/22/2021 at 1:46 PM, John Cuthber said: But you did raise the equally irrelevant liquid hydrogen. Actually no I didn't introduce liquid hydrogen into the thread, the OP did. Quite rightly in my opinion, since discussion of the circumstances when liquid hydrogen may or may not be appropriate and the difficulties involved are very properly part of the discussion here. They are not irrelevant. And yes I did read all the words, which is why I replied offering you a link to a website discussing the some of merits of liqification. And yes you are avoiding discussing the gas which is already in use in liquified form for transportation purposes, notably LPG. @beecee Yes it is great to learn of improved methods of decomposition of water to generate hydrogen. But a good question is How much energy in the form of work needs to be input to collect and store hydrogen gas or liquid in reasonable sized containers ? Will not this reduce the overall efficiency if the system ?
John Cuthber Posted September 24, 2021 Posted September 24, 2021 1 hour ago, studiot said: Actually no I didn't introduce liquid hydrogen into the thread, the OP did. He pointed out that it's impractical. "Liquid hydrogen must be contained at incredibly high pressure or maintained at very low temperatures by complex cryogenic systems. " As far as I can tell, only space rockets use LH2 as a transport fuel- and even they sometimes shy away from it. I don't know of any serious project that is looking at LH2 as an energy storage medium . There are two reasons. 1 it's hard. 2 It's inefficient- you waste a lot of energy cooling and heating it. The thread is about an new trick in the process of making hydrogen; what you do with it after that is a separate issue. Incidentally, 2 hours ago, studiot said: How much energy in the form of work needs to be input to collect and store hydrogen gas or liquid in reasonable sized containers ? If you generate the gas electrolytically, the answer is "none". You don't need to do work compressing it; the reaction will still work at higher pressure but needs a slightly higher voltage. Hydrogen generators exist, so they are clearly "reasonable"
studiot Posted September 24, 2021 Posted September 24, 2021 25 minutes ago, John Cuthber said: You don't need to do work compressing it; the reaction will still work at higher pressure but needs a slightly higher voltage. I look forward to your scientific amplification of this claim.
swansont Posted September 24, 2021 Posted September 24, 2021 You might not need to do work to compress it, but that would mean you expend more energy generating it. That bill still needs to be paid.
studiot Posted September 24, 2021 Posted September 24, 2021 Surely this is a simple application of The First Law ? When you have your vessel of hydrogen, liquid or gaseous, you have a change of internal energy ΔE = ΔH + PΔV The PΔV term will be at the high pressure within the vessel. All of that internal energy will be lost when the hydrogen depressurises to react at normal pressures.
dimreepr Posted September 24, 2021 Posted September 24, 2021 1 hour ago, studiot said: Surely this is a simple application of The First Law ? first law of what?
beecee Posted September 24, 2021 Author Posted September 24, 2021 10 hours ago, studiot said: How much energy in the form of work needs to be input to collect and store hydrogen gas or liquid in reasonable sized containers ? Will not this reduce the overall efficiency if the system ? I would imagine that along with most other forms of alternate energy sources, these are continually being looked at. 1
Ken Fabian Posted September 24, 2021 Posted September 24, 2021 I do think Hydrogen has intrinsic and intractable issues around efficiency in some of the steps. We have losses from electrolysis, losses from storage energy requirements, inefficient burning, inefficient fuel cells. If we include a step to and step back using ammonia we get two more conversions that will have losses. Hypothetically a lot of energy from compressing and condensing can be recovered but in practice is not so easy. The on-site production and storage for industrial applications are able to avoid high pressure storage but transport fuel and transportable fuel requires it. It is the industrial uses that are crucial, without ready alternatives that look the easiest to do and the uses like transport that are more difficult and include inefficiencies that cannot be avoided do have alternatives.
studiot Posted September 25, 2021 Posted September 25, 2021 12 hours ago, beecee said: I would imagine that along with most other forms of alternate energy sources, these are continually being looked at. 10 hours ago, Ken Fabian said: I do think Hydrogen has intrinsic and intractable issues around efficiency in some of the steps. We have losses from electrolysis, losses from storage energy requirements, inefficient burning, inefficient fuel cells. If we include a step to and step back using ammonia we get two more conversions that will have losses. Hypothetically a lot of energy from compressing and condensing can be recovered but in practice is not so easy. The on-site production and storage for industrial applications are able to avoid high pressure storage but transport fuel and transportable fuel requires it. It is the industrial uses that are crucial, without ready alternatives that look the easiest to do and the uses like transport that are more difficult and include inefficiencies that cannot be avoided do have alternatives. Every system has its stengths and weaknesses so thank you to beecee for giving us the opportunity to fully discuss the one based on hydrogen. +1 A further thought / question occurs to me. What would be the design life of such a system? How would that affect the financial and energy whole life costs ? I note for comparison that since the widespread uptake of lithium based rechargeable batteries many are now finding the true cost when the batteries need replacing. 1
beecee Posted September 25, 2021 Author Posted September 25, 2021 11 hours ago, studiot said: I note for comparison that since the widespread uptake of lithium based rechargeable batteries many are now finding the true cost when the batteries need replacing. Good point.................. https://www.csiro.au/en/research/technology-space/energy/Energy-storage/Battery-recycling A serious waste problem As demand grows for energy storage and batteries, so too does the amount of lithium-ion battery waste. The following statistics paint a picture of the challenge: only 2 per cent of Australia's annual 3,300 tonnes of lithium-ion battery waste is recycled this waste is growing by 20 per cent per year and could exceed 100,000 tonnes by 2036 if recycled, 95 per cent of components can be turned into new batteries or used in other industries by comparison, of the 150,000 tonnes of lead-acid batteries sold in 2010, 98 per cent were recycled, and the majority of Australia's battery waste is shipped overseas, and the waste that remains left in landfill, leading to a potential fires and environmental contamination. more at link......................
Ken Fabian Posted September 25, 2021 Posted September 25, 2021 12 hours ago, studiot said: I note for comparison that since the widespread uptake of lithium based rechargeable batteries many are now finding the true cost when the batteries need replacing. "True costs" of batteries... compared to what? The whole climate issue is about including true costs that otherwise don't get counted. Replacement costs vs the utility? I think Li-ion is doing well on that scale and battery tech is still a work in progress. My understanding is that most of the earliest Tesla's still have the original batteries and most can expect a longer working life with less maintenance than ICE drivetrains. But I don't expect Li-ion to stay the same or to be the only viable chemistry. 1 hour ago, beecee said: A serious waste problem It is disappointing that you aren't putting those numbers into perspective. I think there is a strong thread of alarmist fear about the resource requirements and wastes of renewable energy that is being encouraged by opponents of climate accountability and supporters of fossil fuels and I don't think it is warranted; I urge you not to buy into it. It is not that there are not problem wastes from RE but that the problem wastes from fossil fuel burning are so, so, so abundant as well as intractable. Australia makes 12.5 million tons a year of serious problem waste in the form of coal ash - 125x expected battery waste in a heavily RE and battery dependent 2036 - and 4,000 times as much CO2 as that. Neither waste is amenable to recycling - I am not convinced including fly ash in concrete can be scaled sufficiently, nor that it won't leave an enduring legacy of heavy metals contaminated concrete. CCS (with 2-3 tons of CO2 for each ton of FF burned) can't scale up and is just Greenwash. There is recognition of the need for solutions to RE waste - and supporters of fossil fuels won't stop reminding us. Renewable energy industry overall tends to accept the need to develop recycling/safe disposal and appears open to inclusion of pre-payment for disposal in initial purchase. I don't think recycling/safe disposal is even possible for fossil fuels wastes but the industry fiercely opposes any accountability. I would note that EV and large scale batteries are very unlikely to enter ordinary waste streams and it is small consumer item batteries that are a fire risk. No vehicle recycler is going to be stupid enough to put them in the crusher (well, let's hope not) and no ordinary landfill will accept them. We will deal with the wastes - that will be in much reduced volumes compared to FF's and, foreseeing the issues, will probably do so better at it than we've handled problem wastes in the past. 1
beecee Posted September 25, 2021 Author Posted September 25, 2021 7 minutes ago, Ken Fabian said: It is disappointing that you aren't putting those numbers into perspective. It is even more disappointing that you fail to see That all I have done [without any qualifications or opinions] is recognise the "good pont" made by studiot re waste, and what I could find on that particular issue. 12 minutes ago, Ken Fabian said: There is recognition of the need for solutions to RE waste - yes there is...full stop. 13 minutes ago, Ken Fabian said: I would note that EV and large scale batteries are very unlikely to enter ordinary waste streams and it is small consumer item batteries that are a fire risk. No vehicle recycler is going to be stupid enough to put them in the crusher (well, let's hope not) and no ordinary landfill will accept them. We will deal with the wastes - that will be in much reduced volumes compared to FF's and, foreseeing the issues, will probably do so better at it than we've handled problem wastes in the past. And that's what the article also concerns itself with. Plus I wouldn't really be telling the stupid vehicle recyclers that do put them where they aint supposed to be, that they don't put them where they aint supposed to be...really! 18 minutes ago, Ken Fabian said: We will deal with the wastes Yes, as suggested by the article https://publications.csiro.au/publications/publication/PIcsiro:EP208519/SQbattery lithium/RP1/RS25/RORECENT/STsearch-by-keyword/LISEA/RI2/RT72 I believe my position on this issue should be clear. Afterall, it was my OP and I have reiterated many times that we should be doing the utmost scientifically in introducing all forms of clean alternate forms of energy and recognising that every system has its stengths and weaknesses, and research must continue to iron out those weaknesses and promote the strengths.
John Cuthber Posted September 26, 2021 Posted September 26, 2021 (edited) On 9/24/2021 at 1:35 PM, studiot said: I look forward to your scientific amplification of this claim. Which bit don't you understand? This https://en.wikipedia.org/wiki/Nernst_equation which says the voltage depends on the pressure, or do you not understand the idea that you can store gas at constant pressure in something like this? https://en.wikipedia.org/wiki/Gas_holder Since the gas pressure never changes, the gas is never compressed, no work is done compressing it. On 9/24/2021 at 2:13 PM, swansont said: You might not need to do work to compress it, but that would mean you expend more energy generating it. That bill still needs to be paid. That's why the voltage is higher. Edited September 26, 2021 by John Cuthber
dimreepr Posted September 26, 2021 Posted September 26, 2021 3 hours ago, John Cuthber said: Which bit don't you understand? This https://en.wikipedia.org/wiki/Nernst_equation which says the voltage depends on the pressure, or do you not understand the idea that you can store gas at constant pressure in something like this? https://en.wikipedia.org/wiki/Gas_holder Since the gas pressure never changes, the gas is never compressed, no work is done compressing it. That's why the voltage is higher. Does that mean we can adapt our current infrastructure to accommodate hydrogen?
John Cuthber Posted September 26, 2021 Posted September 26, 2021 4 hours ago, dimreepr said: Does that mean we can adapt our current infrastructure to accommodate hydrogen? Watch this space. https://hydeploy.co.uk/faqs/what-is-hydeploy/
Ken Fabian Posted September 27, 2021 Posted September 27, 2021 On 9/26/2021 at 9:44 AM, beecee said: - all I have done [without any qualifications or opinions] is recognise the "good pont" made by studiot re waste But I don't think it is that good a point, which is why I urge you - and urge Studiot too btw - not to buy into the alarmist fears of renewable energy wastes. Maybe the big bold heading "a serious waste problem" was a copy and paste, not you warning of the dangers of committing to renewable energy - but I think it deserved some qualifications, if only to make clear your opinion. I don't necessarily follow links, but I was aware of that study on battery waste in Australia and see it as evidence the problems with waste are not being ignored. And maybe the strength of my response was less about you and more about the widespread use of those alarmist fears to undercut confidence in committing to clean energy. We probably agree on more than we disagree; just more likely to get exchanges of views where we disagree. It seems to me we have passed the point where weighing up our future options is the best use of our resources - we have options that work, if imperfectly, and pathways that are clear for the near term, even if less clear for the longer term. (A general observation, not specific to any posts). Battery electric looks like the current best option for transport but any commitment to it doesn't lock us into anything we cannot change; it looks flexible to me and that flexibility looks more important than waiting on a clear and unambiguous overarching "plan". If Hydrogen does emerge as cost effective for transport that will be good but holding out on commitment to low emissions transport whilst we wait for it will squander the opportunities we have now.
beecee Posted September 27, 2021 Author Posted September 27, 2021 (edited) 2 hours ago, Ken Fabian said: not to buy into the alarmist fears of renewable energy wastes. That certainly is the furthest thing from my mind. 2 hours ago, Ken Fabian said: Maybe the big bold heading "a serious waste problem" was a copy and paste, not you warning of the dangers of committing to renewable energy - but I think it deserved some qualifications, if only to make clear your opinion. OK, point taken. 2 hours ago, Ken Fabian said: And maybe the strength of my response was less about you and more about the widespread use of those alarmist fears to undercut confidence in committing to clean energy. We probably agree on more than we disagree; just more likely to get exchanges of views where we disagree. Accepted. 2 hours ago, Ken Fabian said: Battery electric looks like the current best option for transport but any commitment to it doesn't lock us into anything we cannot change; it looks flexible to me and that flexibility looks more important than waiting on a clear and unambiguous overarching "plan". If Hydrogen does emerge as cost effective for transport that will be good but holding out on commitment to low emissions transport whilst we wait for it will squander the opportunities we have now. Personally I don't know enough about all the alternatives, to accurately have an opinion on which is best. [I have also heard and reject some of the noise that was once topical about the application and use of wind farms] Solar power panels [of which I have had installed for 2 years] also have "minor" cons [dirt etc] but thankfully I am still able to access them for their yearly clean up. Thanks for your contribution, even if I perhaps did misconstrue some of your points. Edited September 27, 2021 by beecee
exchemist Posted September 27, 2021 Posted September 27, 2021 (edited) 7 hours ago, Ken Fabian said: But I don't think it is that good a point, which is why I urge you - and urge Studiot too btw - not to buy into the alarmist fears of renewable energy wastes. Maybe the big bold heading "a serious waste problem" was a copy and paste, not you warning of the dangers of committing to renewable energy - but I think it deserved some qualifications, if only to make clear your opinion. I don't necessarily follow links, but I was aware of that study on battery waste in Australia and see it as evidence the problems with waste are not being ignored. And maybe the strength of my response was less about you and more about the widespread use of those alarmist fears to undercut confidence in committing to clean energy. We probably agree on more than we disagree; just more likely to get exchanges of views where we disagree. It seems to me we have passed the point where weighing up our future options is the best use of our resources - we have options that work, if imperfectly, and pathways that are clear for the near term, even if less clear for the longer term. (A general observation, not specific to any posts). Battery electric looks like the current best option for transport but any commitment to it doesn't lock us into anything we cannot change; it looks flexible to me and that flexibility looks more important than waiting on a clear and unambiguous overarching "plan". If Hydrogen does emerge as cost effective for transport that will be good but holding out on commitment to low emissions transport whilst we wait for it will squander the opportunities we have now. It is interesting to me that you are so concerned about people using the side effects of these new energy systems as an argument for delay. I must say I see little or none of this in Europe. The various arguments are about pros and cons of alternatives, not to stymie progress but to make sure we go into them with our eyes open to the side-effects, and some plans in place to deal with them . This is historically not something the human race has been very good at - hence the crisis we now find ourselves in. Nuclear is a case in point. We probably have no option but to retain nuclear as part of the energy mix for electricity generation, but we need to be aware it is probably the most expensive option, if we include full cradle-to-grave costs. None of these alternatives is problem-free. Myself, I think that is a good argument for backing several horses rather than trying to pick a winner: there may be further unforeseen consequences with any of these routes. Edited September 27, 2021 by exchemist
Ken Fabian Posted September 28, 2021 Posted September 28, 2021 Maybe I'm a bit sensitive - I'd encountered people making the "cure worse than problem" argument citing renewable waste recently. As an argument for not making and selling and using things that are in demand citing future waste obviously doesn't work very well anyway - and their position ultimately depended on presuming climate impacts from fossil fuels to be exaggerated. Sigh. Even so I think too few people, even reasonably well informed ones, realise just how much problem waste fossil fuel use produces - and it is worth highlighting how much less the total volumes using renewable energy can be expected to make. Dealing with waste too often has come as an afterthought, or perhaps as and after the waste problems present themselves. I would expect manufacturing wastes at large scale to present as a problem quite quickly and safe disposal becomes a working necessity, with relatively few high volume sources making it hard to ignore. End use waste becoming the user's problem presents less directly or immediately. RE will be at scales that are off the scale if they are to work for 10 billion people, so yes we will need to deal with the wastes responsibly. I see building an abundance of clean energy as the best thing we can do and it surprises and astonishes me that wind and solar have emerged as a cost effective action - such that we can and are using them in serious volumes. If renewable Hydrogen is to have a significant role it requires that clean energy growth and more, so committing to more solar and wind right now makes sense. And this appears to be happening and is cause for cautious optimism that, despite appearances, that we can make a real difference. From 1.7% of global electricity in 2010 Wind and Solar have grown to 8.7% of a larger total in 2020; by any measure that is extraordinary growth, but I think we ain't seen nothing yet, because crossing a crucial tipping point on costs (in most places during that decade) has not fully flowed through. How much energy storage can grow is a question but batteries are emerging as serious contributors. I note that about 20 times more electricity supply batteries (grid and domestic) have been built in Australia since 2016 than predictions at the time. Power companies that previously assumed a growing role for gas as backup are choosing to use batteries and are questioning those plans. Ongoing R&D and support for pilot programs for many other contributing technologies and options is essential because Wind and Solar can't do it all. Hydrogen is one. Energy storage of all kinds is another - battery R&D has gained it's own momentum and high levels of commercial funding. So is growing interconnections across ever wider electricity grids something I think worthwhile - whether it is Africa to Europe, Australian to SE Asia (SunCable tm) or the UK linked to Iceland hydrothermal power (due for completion soon?).
beecee Posted November 21, 2021 Author Posted November 21, 2021 https://phys.org/news/2021-11-single-atom-dimer-electrocatalyst-green-hydrogen.html Two is better than one: Single-atom dimer electrocatalyst for green hydrogen production Representation models of a) nickel single-atom, b) cobalt single-atom, c) nickel-cobalt single-atom dimer (NiCO-SAD-NC), and d) nickel-cobalt heterogeneous nanoparticle catalysts. Credit: Institute for Basic Science (William I. Suh) The limited reservoir of fossils fuels and the ever-increasing threats of climate change have encouraged researchers to develop alternative technologies to produce eco-friendly fuels. Green hydrogen generated from the electrolysis of water using renewable electricity is considered a next-generation renewable energy source for the future. But in reality, the overwhelming majority of hydrogen fuel is obtained from the refining of fossils fuels due to the high cost of electrolysis. Currently, the efficiency of water electrolysis is limited and often requires high cell voltage due to the lack of efficient electrocatalysts for hydrogen evolution reactions. Noble metals such as platinum (Pt) are used as catalysts to improve hydrogen generation in both acidic/alkaline media. However, these noble metal catalysts are very expensive and show poor stability under long-term operation. Single-atom catalysts have advantages over their nanomaterial-based counterparts, achieving up to 100 percent atom utilization, whereas only the surface atoms of nanoparticles are available for reaction. However, due to the simplicity of the single-metal-atom center, carrying out further modification of the catalysts to perform complex multistep reactions is rather difficult. more at link...................... the paper: https://www.nature.com/articles/s41467-021-27145-3.pdf Moving beyond bimetallic-alloy to single-atom dimer atomic-interface for all-pH hydrogen evolution: Single-atom-catalysts (SACs) afford a fascinating activity with respect to other nanomaterials for hydrogen evolution reaction (HER), yet the simplicity of single-atom center limits its further modification and utilization. Obtaining bimetallic single-atom-dimer (SAD) structures can reform the electronic structure of SACs with added atomic-level synergistic effect, further improving HER kinetics beyond SACs. However, the synthesis and identification of such SAD structure remains conceptually challenging. Herein, systematic first-principle screening reveals that the synergistic interaction at the NiCo-SAD atomic interface can upshift the d-band center, thereby, facilitate rapid water-dissociation and optimal proton adsorption, accelerating alkaline/acidic HER kinetics. Inspired by theoretical predictions, we develop a facile strategy to obtain NiCo-SAD on N-doped carbon (NiCo-SAD-NC) via in-situ trapping of metal ions followed by pyrolysis with precisely controlled N-moieties. X-ray absorption spectroscopy indicates the emergence of Ni-Co coordination at the atomic-level. The obtained NiCo-SAD-NC exhibits exceptional pH-universal HER-activity, demanding only 54.7 and 61 mV overpotentials at −10 mA cm−2 in acidic and alkaline media, respectively. This work provides a facile synthetic strategy for SAD catalysts and sheds light on the fundamentals of structure-activity relationships for future applications.
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