4 ms·

This is remarkably hard to follow. The actual technology at play here is bicarbonate-formate redox; as the linked paper states: >It is also clear that more int

by scythe 3y ago

This is remarkably hard to follow. The actual technology at play here is bicarbonate-formate redox; as the linked paper states: >It is also clear that more integration between the disciplines of electrochemistry and heterogeneous catalysis is needed to overcome the challenges for advancing the HCO3−–HCO2− system as a feasible green alternative for storing and transporting energy. The idea of storing energy by converting bicarbonate to formate has already occurred to me years ago and probably was thought of by thousands of other scientists, because formate is one of the most common hydrogen precursors used in practical chemistry. The storage density is low, but the materials are extremely cheap and stable. Unfortunately, the paper does not seem to be announcing a breakthrough, but tallying up the current progress — which just isn't there yet. https://pubs.rsc.org/en/content/articlelanding/2023/gc/d3gc00219e https://pubs.rsc.org/en/content/articlelanding/2023/gc/d3gc0...

jfengel 3y ago
I suppose... a "hydrogen battery" for solar? Build up formate (in solution? As a salt?) during the day, then burn it at night for electricity?
- rfgmendoza 3y ago
  density is not really a critical factor for grid level or onsite energy storage, so it could be feasible in theory
  - elcritch 3y ago
    As long as the electrodes / membranes for the conversion to electricity are stable and cheap as well. There's a big downside with PEM electrodes requiring platinum and with their longevity and energy density relative to capex.
chrisco255 3y ago
The article wastes so much time on cutesy fluff. It's almost always a tell that the story is a non-story.
elcritch 3y ago
Thanks for linking the real article. It's an interesting read, especially that the Gibb's Free Energy for formate-bicarbonate is so low. Ammonia is about 20-40x higher! Looks like they're using Pd/Pt for the best catalyzers... that's definitely not going to be scalable. Though there should be effective alternatives, but it's surprising how unsophisticated much of the research in this field can be.
csense 3y ago
I don't really have much understanding of chemistry. So possibly the most helpful part for me is the diagram with little trucks, the cost chart, and the paragraph below that says: "The electrochemical regeneration is not optimized...If the cell voltage could be reduced to 2 V and the faradaic efficiency raised to 80%, the total cost of hydrogen would be nearly cut in half...if the regeneration and reaction could be performed at 8 M rather than 3 M concentration along with an improved process and discounted electricity...the cost of hydrogen could drop to just over $3 per kg...[which is] below the cost of on-site electrolysis with full-priced electricity" Why formate? Can't you get hydrogen from any acid, because that's literally the definition of an acid? "If the cell voltage could be reduced" sounds super fishy to me; isn't that just a useless wish that the elements / molecules you're working with have different properties than they actually do? "If the regeneration and reaction could be performed at 8 M rather than 3 M concentration...", why can't they? Doesn't a reaction usually proceed faster in more concentrated solutions? It seems like several breakthroughs that are needed, some of which possibly stretch the laws of physics. But once you have that. But even with those improvements, they still compare formate+discounted electricity to electrolysis+fullprice electricity? Isn't that doing an apples-to-oranges comparison, blatantly putting your thumb on the scale in favor of formate? For that matter, what's wrong with electrolysis for making hydrogen for bulk energy storage? Isn't water electrolysis super well-understood, cheap, simple, scalable, as safe as anything involving bulk quantities of hydrogen gas can be, and only requires water and electricity for inputs?
- scythe 3y ago
  >Why formate? Can't you get hydrogen from any acid, because that's literally the definition of an acid? Formate releases hydrogen differently: HCOOH >> H2 + CO2 Other acids need an electron donor to produce hydrogen. Formate reduces itself. >"If the regeneration and reaction could be performed at 8 M rather than 3 M concentration...", why can't they? You're getting a little over my head here, but I think there might be some solubility problems. >"If the cell voltage could be reduced" sounds super fishy to me; isn't that just a useless wish that the elements / molecules you're working with have different properties than they actually do? The standard electrode potential does create a minimum voltage, but usually there is considerable inefficiency. I can't answer the other questions, except to mention that formate is very stable and easy to store.

by scythe 3y ago

jfengel 3y ago

I suppose... a "hydrogen battery" for solar? Build up formate (in solution? As a salt?) during the day, then burn it at night for electricity?

rfgmendoza 3y ago
density is not really a critical factor for grid level or onsite energy storage, so it could be feasible in theory
- elcritch 3y ago
  As long as the electrodes / membranes for the conversion to electricity are stable and cheap as well. There's a big downside with PEM electrodes requiring platinum and with their longevity and energy density relative to capex.

chrisco255 3y ago

The article wastes so much time on cutesy fluff. It's almost always a tell that the story is a non-story.

elcritch 3y ago

Thanks for linking the real article. It's an interesting read, especially that the Gibb's Free Energy for formate-bicarbonate is so low. Ammonia is about 20-40x higher! Looks like they're using Pd/Pt for the best catalyzers... that's definitely not going to be scalable. Though there should be effective alternatives, but it's surprising how unsophisticated much of the research in this field can be.

csense 3y ago

I don't really have much understanding of chemistry. So possibly the most helpful part for me is the diagram with little trucks, the cost chart, and the paragraph below that says: "The electrochemical regeneration is not optimized...If the cell voltage could be reduced to 2 V and the faradaic efficiency raised to 80%, the total cost of hydrogen would be nearly cut in half...if the regeneration and reaction could be performed at 8 M rather than 3 M concentration along with an improved process and discounted electricity...the cost of hydrogen could drop to just over $3 per kg...[which is] below the cost of on-site electrolysis with full-priced electricity" Why formate? Can't you get hydrogen from any acid, because that's literally the definition of an acid? "If the cell voltage could be reduced" sounds super fishy to me; isn't that just a useless wish that the elements / molecules you're working with have different properties than they actually do? "If the regeneration and reaction could be performed at 8 M rather than 3 M concentration...", why can't they? Doesn't a reaction usually proceed faster in more concentrated solutions? It seems like several breakthroughs that are needed, some of which possibly stretch the laws of physics. But once you have that. But even with those improvements, they still compare formate+discounted electricity to electrolysis+fullprice electricity? Isn't that doing an apples-to-oranges comparison, blatantly putting your thumb on the scale in favor of formate? For that matter, what's wrong with electrolysis for making hydrogen for bulk energy storage? Isn't water electrolysis super well-understood, cheap, simple, scalable, as safe as anything involving bulk quantities of hydrogen gas can be, and only requires water and electricity for inputs?

scythe 3y ago
>Why formate? Can't you get hydrogen from any acid, because that's literally the definition of an acid? Formate releases hydrogen differently: HCOOH >> H2 + CO2 Other acids need an electron donor to produce hydrogen. Formate reduces itself. >"If the regeneration and reaction could be performed at 8 M rather than 3 M concentration...", why can't they? You're getting a little over my head here, but I think there might be some solubility problems. >"If the cell voltage could be reduced" sounds super fishy to me; isn't that just a useless wish that the elements / molecules you're working with have different properties than they actually do? The standard electrode potential does create a minimum voltage, but usually there is considerable inefficiency. I can't answer the other questions, except to mention that formate is very stable and easy to store.