[HN Gopher] A Baking Soda Solution for Clean Hydrogen Storage
___________________________________________________________________
A Baking Soda Solution for Clean Hydrogen Storage
Author : geox
Score : 26 points
Date : 2023-06-12 23:04 UTC (23 hours ago)
(HTM) web link (www.pnnl.gov)
(TXT) w3m dump (www.pnnl.gov)
| photochemsyn wrote:
| Hydrogen is needed for all kinds of industrial processes, but it
| is best generated at the point of use as needed, as storage and
| transport is too problematic. If absoultely needed, the most
| obvious way to ship hydrogen is as methane.
|
| Synthesis of methane from water-sourced hydrogen and atmosphere-
| sourced CO2 is at present a good deal more expensive than fossil
| natural gas, but that's a somewhat artificial situation: natural
| gas production is heavily subsidized and many of the costs are
| externalized to the public (see global warming, air and water
| pollution, etc.). However, once accomplished you can just feed
| this renewable methane into the existing natural gas
| infrastructure, and get the hydrogen back as needed from well-
| understood processes, i.e. steam-methane reforming.
| hannob wrote:
| > If absoultely needed, the most obvious way to ship hydrogen
| is as methane.
|
| Methane has 2 problems: 1. it's a massive greenhouse gas if it
| leaks, 2. it requires CO2 to make, and in a decarbonized future
| that can only come from either biomass (limited) or DAC
| (expensive).
|
| You would either want ammonia or methanol. Ammonia does not
| have any of these problems, but it's very toxic. Methanol has
| the CO2 problem as well, but it's a liquid, so it's easier to
| transport. Neither is perfect, but there are no perfect
| solutions.
|
| Methane is the worst of all options. If you want a hydrocarbon,
| then usually methanol is what you want. And don't trust me on
| that, just look at what projects are actually planned out
| there. Plenty of green ammonia and green methanol projects,
| green methane is exotic at best, barely anyone wants to do
| that.
| marcosdumay wrote:
| > Ammonia does not have any of these problems
|
| Ammonia is a greenhouse gas itself, and it tends to react
| with air creating various nitrous oxides, that are much more
| potent greenhouse gases than methane, very toxic, and create
| acid rain (after what it becomes fertilizer).
|
| The best shipping option is probably just to face all the
| issues and ship the hydrogen. But storage is a different
| matter.
| hannob wrote:
| Ammonia is no greenhouse gas, it has a GWP of zero. Burning
| ammonia produces N2O, which is a potent greenhouse gas, and
| NOx, which is an air pollutant. But these can be taken care
| of by scrubbers, and are irrelevant if you ship ammonia for
| other uses. (I mean the biggest use case of hydrogen these
| days is making ammonia for fertilizers.)
| photochemsyn wrote:
| It's not a greenhouse gas if you make it from atmospheric
| CO2, that's the whole point. Also, sending methane through a
| pipeline is pretty straightforward. Methanol is an option on
| the liquid side, but if you can make methanol from
| atmospheric CO2 and water, you can also make jet fuel, which
| will be needed as jet travel isn't really electrifiable.
| bagels wrote:
| "In a renewable energy grid, batteries can handle about 80
| percent of storage needs."
|
| Why couldn't you just add 25% more batteries?
| ZeroGravitas wrote:
| Most storage is short term, so the same battery can be re-used
| again and again by charging and discharging it, e.g. 365 solar
| peaks a year in sunny countries. Longer term storage would lock
| up the battery for longer, which given the cost of batteries,
| wouldn't make financial sense.
| marcosdumay wrote:
| It's not 25% more batteries. It's some 500% to 1000% more. But
| those would be used very few times.
| chrisco255 wrote:
| So in other words batteries don't get us anywhere close to
| 80% of the way.
| elcritch wrote:
| Depends on how you're slicing it. By the total flux of
| energy batteries may be able to handle 80% of the "energy
| traffic" over the course of a day by smoothing out
| day/night cycles.
|
| However that last 25% needs to be stored over long periods
| where the cost is prohibitive to store in current battery
| systems.
| audunw wrote:
| There's many ways to judge what "80%" is. The batteries
| will cycle many times every week. They will have much more
| energy flowing through them in a year than the storage we
| need for dunkelflaute would.
|
| Yes, in terms of amount of energy stored at full capacity,
| batteries would not get us to 80%. But those last 20% have
| reduced requirements for charge/discharge rates, effiency,
| cost/kWh, which makes many other solutions viable.
| scythe wrote:
| 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/d3gc0...
| elcritch wrote:
| 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.
| chrisco255 wrote:
| The article wastes so much time on cutesy fluff. It's almost
| always a tell that the story is a non-story.
| jfengel wrote:
| 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 wrote:
| density is not really a critical factor for grid level or
| onsite energy storage, so it could be feasible in theory
| elcritch wrote:
| 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.
| wilg wrote:
| [flagged]
___________________________________________________________________
(page generated 2023-06-13 23:03 UTC)