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Gallium helps convert CO2 into Carbon and Oxygen

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Re: Gallium helps convert CO2 into Carbon and Oxygen

#31

Post by api »

cletus wrote: post #11

So let's do some math. Let's consider natural gas. According to the US government [1], natural gas produced 1.358x10^12 kWh of power and 5.6x10^8 metric tons of CO2 so 1 metric ton of CO2 equates to ~2400 kWh of produced power. This post suggests the energy cost is ~230kWh/ton. This is an important sanity check because it means that (capital costs aside) and if it scales you could technically remain carbon neutral fo…

To those who think it sounds impossible, remember that methane is CH4 and a good amount of the energy released is attributable to those hydrogens getting together with oxygen. So you are basically subtracting the yield from carbon.

Wouldn’t it be a lot better though to somehow turn CH4 into hydrogen and carbon, bury the carbon or use it for uses that don’t end up in the atmosphere, and burn the hydrogen alone or use it in fuel cells? Fuel cells might get you to pretty good energy yields.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#32

Post by valw »

Lev1a wrote: post #6
Waterluvian wrote: post #2

I’m not sure: is the Gallium a catalyst?

And if so, could it be replaced by orgnano-catalysts which were in the news recently? I only had chemistry in school but maybe it's even as simple as using parts from the chemistry involved in photosynthesis?

Folks, just to clarify: "catalyst" is a very broad chemistry term for "something that helps a chemical reaction take place without being a reagent nor product of said reaction." So don't get the wrong idea: catalysts have quite specific uses, and you cannot substitute any one catalyst for any other.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#33

Post by adrian_b »

Waterluvian wrote: post #2

I’m not sure: is the Gallium a catalyst?

The process described in the paper uses both gallium and silver as catalysts.

The advantage of using gallium is that it is in liquid form. When the gallium is regenerated after catalyzing one cycle of the reaction, it mixes again with the liquid gallium.

Being liquid ensures a long life for the catalyst. Solid catalysts are never recovered perfectly after taking part in the reaction and then being again deposited on their support, so they degrade much faster.

The mechanism of solid catalyst degradation is similar to that which limits the life of a rechargeable battery with solid electrodes.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#34

Post by cletus »

adrian_b wrote: post #19
cletus wrote: post #11

So let's do some math. Let's consider natural gas. According to the US government [1], natural gas produced 1.358x10^12 kWh of power and 5.6x10^8 metric tons of CO2 so 1 metric ton of CO2 equates to ~2400 kWh of produced power. This post suggests the energy cost is ~230kWh/ton. This is an important sanity check because it means that (capital costs aside) and if it scales you could technically remain carbon neutral fo…

"how the CO2 needs to be delivered": The experiments described in the paper have used pure CO2. The conversion process is unlikely to work directly with air, because it decomposes CO2 into solid carbon partially oxidated and dioxygen. If one of the products of the catalyzed reaction, i.e. oxygen from the air, would be present in a much larger concentration than the input substance (CO2), like in the air, the conversi…

A big issue with renewable energy, particularly solar and wind, is that the power output is variable and an electric grid needs a base load to operate.

Now I firmly believe the future here is ultimately space-based solar power collectors. I've seen estimates that a panel in space around Earth can generate ~7 times the power it can on Earth. This is a deep topic but generating power in space for use on Earth isn't as crazy as it may sound.

Anyway, another potential application is to use variable power output for useful purposes on-site. For example, you can extract CO2 directly from the atmosphere and with simply chemistry you can make gasoline from that. This is currently cost-prohibitive so no one does it.

At some point this may become economic, in which case the variable power output won't be an issue. You're now only interested in the total output. You also don't lose power from transmission or require the capital cost of transmission lines.

Perhaps CO2 capture is another potential such application. Either the CO2 could be processed on site with a process like this and the byproducts (pure carbon and oxygen) can be sold.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#35

Post by Waterluvian »

valw wrote: post #32
Lev1a wrote: post #6

Earlier quoted context omitted.

And if so, could it be replaced by orgnano-catalysts which were in the news recently? I only had chemistry in school but maybe it's even as simple as using parts from the chemistry involved in photosynthesis?

Folks, just to clarify: "catalyst" is a very broad chemistry term for "something that helps a chemical reaction take place without being a reagent nor product of said reaction." So don't get the wrong idea: catalysts have quite specific uses, and you cannot substitute any one catalyst for any other.

Yes. Thanks for that clarification. What I meant in my original question is if we consume huge amounts of gallium to do this. Ie. can it scale?

Re: Gallium helps convert CO2 into Carbon and Oxygen

#37

Post by adrian_b »

Waterluvian wrote: post #35
valw wrote: post #32

Earlier quoted context omitted.

Folks, just to clarify: "catalyst" is a very broad chemistry term for "something that helps a chemical reaction take place without being a reagent nor product of said reaction." So don't get the wrong idea: catalysts have quite specific uses, and you cannot substitute any one catalyst for any other.

Yes. Thanks for that clarification. What I meant in my original question is if we consume huge amounts of gallium to do this. Ie. can it scale?

It depends a lot on which will be the lifetime of the catalyst at industrial scales.

Gallium is one of the most expensive metals, not because it is very rare, but because it is very diluted. There are no minerals with a high concentration of gallium, enough to make their commercial exploitation worthwhile.

There are no mines of gallium. Gallium is always extracted as a secondary product in mining operations where either aluminum or zinc is the main product.

Because of that, the available quantity of gallium depends on the volume of the productions of aluminum and of zinc, and it follows their yearly oscillations.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#38

Post by dooferlad »

cletus wrote: post #25
andi999 wrote: post #14

Earlier quoted context omitted.

So reducing petrol demand (let's say by switching to electric cars) might reduce the economic incentives of carbon capture significantly, interesting thought.

Electrifying vehicles at a mass scale actually has a lot of problems, not the least of which is does the grid support the ability to transmit that much power. In many places it does not. That aside, electrifying vehicles doesn't necessarily reduce emissions significantly. It may simply shift the emissions from individual vehicles to the power plant that produces the power that charges the cars. Now this is nearly alw…

Grid stress in the first world isn't a big problem since electric vehicles can charge when the grid is under less pressure. The demand curve over a day has a reasonably predictable shape and EV charging can often be done when wholesale prices are low. Of course we will need to increase capacity, but that can be done over time.

Fossil power to generate electricity that then powers your car is less carbon intensive than just using an internal combustion engine. The overhead of getting oil out of the ground, refining it and transporting it is big. You then lose lots of energy as heat as you run your engine.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#39

Post by GistNoesis »

javier_cardona wrote: post #3

A preprint of the paper mentioned in the post is available here: https://www.researchgate.net/publication/347609399_Mechanica...

The following link has the additional supplementary images missing from your link https://www.researchsquare.com/article/rs-112257/v1

I quickly skimmed it but the protocol on page 13 seems simple, the chemicals involved are relatively low risk (verify the MSDS).

Mix some gallium metal with a powder of a Silver salt in a mortar and pestle, put it in a solvent, stir it with a magnetic stirrer, while bubbling CO2, in a N2 atmosphere, and carbon snowflakes should float to the top in a few hours.

Maybe some chemist can help make it into a safe for all kid science-fair project.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#40

Post by ZeroGravitas »

cletus wrote: post #25
andi999 wrote: post #14

Earlier quoted context omitted.

So reducing petrol demand (let's say by switching to electric cars) might reduce the economic incentives of carbon capture significantly, interesting thought.

Electrifying vehicles at a mass scale actually has a lot of problems, not the least of which is does the grid support the ability to transmit that much power. In many places it does not. That aside, electrifying vehicles doesn't necessarily reduce emissions significantly. It may simply shift the emissions from individual vehicles to the power plant that produces the power that charges the cars. Now this is nearly alw…

I remember when EVs where a pointless toy for rich people to flaunt their wealth, now they're causing problems by letting poor people drive more. That's some remarkble progress they've made while still somehow remaining vaguely problematic.
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