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Engineers find neat way to turn waste carbon dioxide into useful material

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Re: Engineers find neat way to turn waste carbon dioxide into useful material

#11

Post by credit_guy »

The application doesn't really make sense the way they explain it: use CO2 from a power plant to produce syngas. If the power plant burns methane, you might as well produce syngas straight out of methane, and short-circuit the step where you produce CO2. From the net energy usage point of view, you are better off (otherwise, you just found a recipe for perpetual motion).

Where this could make sense is energy storage. Say you are next to a large solar power plant, and you want to store the excess energy produced during the day and release it at night. Batteries are too expensive, pumped water requires some mountains, etc. With this, you store a quantity of CO2 in some tanks. At day you generate syngas and consume electricity, and store it in some other tanks. At night, you burn the syngas, get some of the initial electricity back, and store the CO2 back in its tanks.

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#13

Post by elcritch »

philipkglass wrote: post #9
Animats wrote: post #7

“We used an open flame, which burns at 2000 degrees, to create nanoparticles of zinc oxide that can then be used to convert CO2, using electricity, into syngas.” Is this a real catalyst? (That is, it doesn't get used up in the process.) Or do they have to keep making more zinc oxide clouds to keep the process going? The paper summary is unclear about the energy inputs to this process. Costs $10 to read the paper.

It's a real catalyst. Full paper here: https://sci-hub.tw/10.1002/aenm.202001381 I don't think it will have industrial significance any time soon, though. Catalysts and processes for the reverse water-gas shift reaction are better developed. The hope is that electrochemical catalysts like this can combine the electrolysis process for making H2 and the syngas production step into one, with lower equipment costs. It's…

Do you have more resources regarding the current state of art for the separate processes?

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#14

Post by regularfry »

bit_logic wrote: post #10

Every time there’s a discussion about synthetic carbon fuels, there’s the same frustrating replies. I want to reply to those with one statement: the whole point is to use excess power from solar/wind. There’s always the same replies pointing out how it’s more efficient to use the power directly in EV batteries, laws of thermodynamics, and other similar things. Those completely miss the point. Solar/wind is going expo…

I was going to ask if anyone knew what the efficiency of this process was. Obviously we can't get a perpetual motion machine out of it, so it must be taking more energy to form the syngas than gets released from the fuel in the first place, right?

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#15

Post by WJW »

crimsonalucard1 wrote: post #2

Doesn't the net CO2 in the air increase? So you harvest CO2 to into fuel. That fuel is burned and the CO2 is released back into the air. So net difference is zero. But to harvest the CO2 you needed to generate a high amount of heat. That's extra CO2. So net CO2 is more. It depends on the cost of harvesting that CO2.

You can get the required high amount of heat either through concentrating solar collectors or through any renewable form of electricity that you run through electric heaters. If you want to be fancy, you can use microwaves to very selectively heat only the parts you want to heat.

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#16

Post by ZeroGravitas »

bit_logic wrote: post #10

Every time there’s a discussion about synthetic carbon fuels, there’s the same frustrating replies. I want to reply to those with one statement: the whole point is to use excess power from solar/wind. There’s always the same replies pointing out how it’s more efficient to use the power directly in EV batteries, laws of thermodynamics, and other similar things. Those completely miss the point. Solar/wind is going expo…

You don't need carbon to store energy, you can just stop at hydrogen (or use nitrogen to make ammonia).

Processes can be refitted to use pure hydrogen or it can just be added in small increments to existing gas burning plants.

Replacing anything that burns fuel with carbon in it with alternatives that dont is a better solution.

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#17

Post by [deleted] »

credit_guy wrote: post #11

The application doesn't really make sense the way they explain it: use CO2 from a power plant to produce syngas. If the power plant burns methane, you might as well produce syngas straight out of methane, and short-circuit the step where you produce CO2. From the net energy usage point of view, you are better off (otherwise, you just found a recipe for perpetual motion). Where this could make sense is energy storage.…

[deleted]

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#18

Post by lstodd »

regularfry wrote: post #14
bit_logic wrote: post #10

Every time there’s a discussion about synthetic carbon fuels, there’s the same frustrating replies. I want to reply to those with one statement: the whole point is to use excess power from solar/wind. There’s always the same replies pointing out how it’s more efficient to use the power directly in EV batteries, laws of thermodynamics, and other similar things. Those completely miss the point. Solar/wind is going expo…

I was going to ask if anyone knew what the efficiency of this process was. Obviously we can't get a perpetual motion machine out of it, so it must be taking more energy to form the syngas than gets released from the fuel in the first place, right?

Right.

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#19

Post by p1mrx »

ZeroGravitas wrote: post #16
bit_logic wrote: post #10

Every time there’s a discussion about synthetic carbon fuels, there’s the same frustrating replies. I want to reply to those with one statement: the whole point is to use excess power from solar/wind. There’s always the same replies pointing out how it’s more efficient to use the power directly in EV batteries, laws of thermodynamics, and other similar things. Those completely miss the point. Solar/wind is going expo…

You don't need carbon to store energy, you can just stop at hydrogen (or use nitrogen to make ammonia). Processes can be refitted to use pure hydrogen or it can just be added in small increments to existing gas burning plants. Replacing anything that burns fuel with carbon in it with alternatives that dont is a better solution.

Lots of homes and buildings use natural gas for heat. It would be nice to replace that with something carbon neutral, but the infrastructure can't handle hydrogen levels above 10-20%.

Re: Engineers find neat way to turn waste carbon dioxide into useful material

#20

Post by wtracy »

bit_logic wrote: post #10

Every time there’s a discussion about synthetic carbon fuels, there’s the same frustrating replies. I want to reply to those with one statement: the whole point is to use excess power from solar/wind. There’s always the same replies pointing out how it’s more efficient to use the power directly in EV batteries, laws of thermodynamics, and other similar things. Those completely miss the point. Solar/wind is going expo…

> the whole point is to use excess power from solar/wind.

Thank you.

> But converting that into carbon fuels that work directly in existing infrastructure and is effectively carbon neutral is a good option too.

This approach seems really underrated, at least for transportation.

Hydrocarbons still have the best energy density of the realistic options. We have a century of experience building ICEs with favorable power/weight ratios. Why throw all that away?

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