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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

#61

Post by MaxBarraclough »

PopeDotNinja wrote: post #50
LegitShady wrote: post #42

Earlier quoted context omitted.

>Use the excess summer power to fill up a near empty dam with desalinated water? Pumped storage hydroelectricity is the biggest form of power storage at the moment, and has efficiencies around 70-80%. The losses for desalinization (pumping through media) are ruinous compared to just pumping uphill, and storing desalinized water means you can't use it without spending potential power. There might be good reasons not t…

As I understand it, the main challenge with pumped storage is that you can't do it everywhere. You need fairly specific geography for it, and it's a big civil engineering project. Here's a good video on by Practical Engineering: https://youtu.be/66YRCjkxIcg

Good video, thanks. It briefly mentions the idea of pumped seawater storage. Is that really any different from using freshwater, other than location?

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

#62

Post by leoedin »

adrianN wrote: post #52
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…

What's missing is a careful differentiation between doing what you said, storing excess energy, and approaches that are popularized, e.g. by carmakers unwilling to invest in R&D, where we keep on relying on hydrocarbons for things like transportation and heating and magically replace them with carbon neutral alternatives. The first approach of using hydrocarbons as an energy buffer makes perfect ecological and econom…

> we simply don't have enough space for wind and solar to feed our thirst for hydrocarbons with renewable power.

I'm not sure if this is the case or not. To give some numbers:

Current global oil consumption is 54225 TWh, or 6.2TW [1] Current global solar panel generation capacity is 628 GW (2019) [2]. Median capacity factor maybe 25% [3] Current global wind power capacity is 650 GW [4]. Median capacity factor maybe ~37% [5]

Other renewables are unlikely to achieve the same growth as wind and solar, so can be ignored.

So we need to install 15x current renewables, times whatever the hydrocarbon creation process efficiency is, to produce all our annual oil demand.

Assuming a 50% process efficiency, we'd need to install 30x what we have now. That's a big installation, but it's not outside the realms of possibility. There's a lot of untouched desert in the world.

[1]: https://ourworldindata.org/grapher/oil-consumption-by-region... [2]: https://en.wikipedia.org/wiki/Solar_power_by_country [3]: https://emp.lbl.gov/pv-capacity-factors [4]: https://wwindea.org/blog/category/statistics/ [5]: https://energynumbers.info/uk-offshore-wind-capacity-factors

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

#63

Post by lugorrr »

namibj wrote: post #58
gpm wrote: post #48

Earlier quoted context omitted.

98% curiosity, 2% lack of faith in our long term ability to keep CO2 levels down to healthy levels (1000ppm is enough that we can detect minor negative effects... I have to wonder if really minor ones exist even at 400 ppm). Wikipedia was similarly not useful for me. Scuba divers and the like apparently use a one-time-use non-regenerative mineral that absorbs CO2. The space station has something that regenerates but…

If you figure out some concrete setup, let me know. I am fairly certain that there are measurable cognitive effects at "just" 500 ppm, and good luck staying below that when you can't just sit at an open window outside of a city. 1000 ppm is btw. enough to feel uncomfortable. Cognitive impairment will be much more subtle.

I am fairly certain that there are measurable cognitive effects at "just" 500 ppm

Well, that would be problematic sooner or later [1].

[1] https://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/co2_data_m...

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

#64

Post by D_Alex »

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…

By golly, I agree! And I would agree even if I wasn't working on technology to achieve this.

Unfortunately, the article does not say how the zinc oxide nanoparticles will help with being able to use solar/wind power to produce syngas.

In fact it is not clear how these nanoparticles could actually be used to make an industrial catalyst. Current catalysts also use nanoparticles - on a substrate with enormous surface area/volume ratio, but these nanoparticles are created on that substrate.

I am curious about what the researchers plan as the next step.

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

#65

Post by adrianN »

jfkebwjsbx wrote: post #59
adrianN wrote: post #52

Earlier quoted context omitted.

What's missing is a careful differentiation between doing what you said, storing excess energy, and approaches that are popularized, e.g. by carmakers unwilling to invest in R&D, where we keep on relying on hydrocarbons for things like transportation and heating and magically replace them with carbon neutral alternatives. The first approach of using hydrocarbons as an energy buffer makes perfect ecological and econom…

How big are the losses to make such a big impact as to say there is not enough space for enough solar/sun farms? 99% or what?

I think you're overestimating the amount of space we have realistically available for renewable energy. At some point I did the math for Germany.

The average German needs around 144sqm of solar panels (located in Germany) to meet their primary energy demand of around 48MWh per year (taking into account average production of solar panels in Germany). Germany has a population density of around 4300sqm / person. So in the ideal case with no storage losses you need to cover more than 3% of Germany with solar panels if you want to meet primary energy demand with solar power. (Wind energy is slightly more dense in Germany, but I haven't done the math there).

Realistically you might get something like 1% of the land area without huge resistance of the local population. Probably less, which is why offshore wind is popular. 100% renewable generation is only realistic because you can safely assume that large parts of the primary energy consumption are wasted. For example internal combustion engines are at best 40% efficient. Burning things for heating also only gets you 1J of heating per Joule expended, whereas heat pumps get you 2-3J. You just can't get away with losing another factor two to generate syngas, or even more if you want liquid fuels.

Of course you can justify some inefficiencies if you're willing to transport energy from far away (say solar power from the Sahara), but that is ridiculously expensive compared to more local generation.

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

#66

Post by adrianN »

leoedin wrote: post #62
adrianN wrote: post #52

Earlier quoted context omitted.

What's missing is a careful differentiation between doing what you said, storing excess energy, and approaches that are popularized, e.g. by carmakers unwilling to invest in R&D, where we keep on relying on hydrocarbons for things like transportation and heating and magically replace them with carbon neutral alternatives. The first approach of using hydrocarbons as an energy buffer makes perfect ecological and econom…

> we simply don't have enough space for wind and solar to feed our thirst for hydrocarbons with renewable power. I'm not sure if this is the case or not. To give some numbers: Current global oil consumption is 54225 TWh, or 6.2TW [1] Current global solar panel generation capacity is 628 GW (2019) [2]. Median capacity factor maybe 25% [3] Current global wind power capacity is 650 GW [4]. Median capacity factor maybe ~…

Thanks for doing the math. On a global scale it does look better than the math I did for Germany.

However, I think 50% process efficiency is too high. High temperature electrolysis is about 60% efficient, but then you only have hot uncompressed hydrogen. There are a number more steps involved to get to a liquid fuel, each of them with considerable losses. I can't find the sources right now but I believe I remember something like 15% end-to-end efficiency for getting to something you can fuel your car with.

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

#67

Post by PopeDotNinja »

MaxBarraclough wrote: post #61
PopeDotNinja wrote: post #50

Earlier quoted context omitted.

As I understand it, the main challenge with pumped storage is that you can't do it everywhere. You need fairly specific geography for it, and it's a big civil engineering project. Here's a good video on by Practical Engineering: https://youtu.be/66YRCjkxIcg

Good video, thanks. It briefly mentions the idea of pumped seawater storage. Is that really any different from using freshwater, other than location?

I imagine the main difference would be salt content, but I can't speak to how that would affect things.

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

#68

Post by ashtonkem »

Godel_unicode wrote: post #54
ashtonkem wrote: post #34

Earlier quoted context omitted.

That’s more efficient, but difficult politically and logistically.

How would that be more efficient? The transmission loss would be outrageous between the summer and winter hemispheres. Compare that with transmission loss for LNG tankers at the moment, effectively 0 even with the occasional leak in transit.

1) The main loss for LNG wouldn’t be transit, it would be efficiency during synthesis.

2) Any inefficiency during transit of LNG isn’t leaks, it’s the fuel burnt moving it around.

3) The cost of building high efficiency LNG power plants wherever you need power is another cost that should be considered.

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

#69

Post by gpm »

lugorrr wrote: post #63
namibj wrote: post #58

Earlier quoted context omitted.

If you figure out some concrete setup, let me know. I am fairly certain that there are measurable cognitive effects at "just" 500 ppm, and good luck staying below that when you can't just sit at an open window outside of a city. 1000 ppm is btw. enough to feel uncomfortable. Cognitive impairment will be much more subtle.

I am fairly certain that there are measurable cognitive effects at "just" 500 ppm Well, that would be problematic sooner or later [1]. [1] https://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/co2_data_m...

Indoors that's problematic today, outdoors we have "awhile" if you make 500 your cutoff, we're only growing at ~2.4 ppm per and the yearly peak is at roughly 420 right now, we can probably count on 20 years before we hit 500 outdoors.

https://www.co2.earth/co2-acceleration

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

#70

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]
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