Gallium helps convert CO2 into Carbon and Oxygen • Hacker News Board

Re: Gallium helps convert CO2 into Carbon and Oxygen

#81

Post by vixen99 » Sat, Oct 23, 2021, 3:44 PM UTC

beders wrote: post #78

If we would charge the fossil fuel industry for the cost of destroying the environment, the millions of lives lost due to pollution, it would become infeasible to pump or mine more stuff out of the ground. We don't need technological solutions, we need political solutions. Now

No, you and I kept up the demand on the fossil fuel industry without which it would not exist and all of us went along with it and now you want them to pay for your and my indulgence. How sweetly ironic! It's never our fault, is it?

Re: Gallium helps convert CO2 into Carbon and Oxygen

#82

Post by BurningFrog » Sat, Oct 23, 2021, 3:45 PM UTC

mcdonje wrote: post #61

dr_dshiv wrote: post #21

Earlier quoted context omitted.

>I'll repeat here--that I don't believe altruism will solve greenhouse gas emissions and global warming: it'll only be solved when it becomes economic to do so. Completely agree. We need governments to ensure externalities (both positive and negative) are reflected in market pricing so that economic forces can operate efficiently. Implication: there must be a debt to pay for past and present GHG output. It should not…

So, a robust carbon tax.

That is the way.

It is however politically impossible in most places.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#83

Post by jvanderbot » Sat, Oct 23, 2021, 3:48 PM UTC

ineedasername wrote: post #72

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…

don't believe altruism will solve greenhouse gas emissions and global warming: it'll only be solved when it becomes economic to do so. You've listed altruism and economics, but may have discounted self-interest-- not financial, but survival. Young adults especially are both at an age where they can expect to feel some especially nasty impacts of climate change, and at a point in their career where they can begin maki…

I think environmental issues are the classic tragedy of the commons. The first to put aside environmental issues in favor of riches will have a disproportionate advantage with a proportionate impact. One country burning gas gets cheap fuel to expand their industries but only has a marginal increase in future global warming and (the worst part) almost no impact on today's temperature.

We need more than altruism, which is local sacrifice. We need global enforcement and agreement and, I agree with GP, incentive.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#84

Post by jandrewrogers » Sat, Oct 23, 2021, 3:51 PM UTC

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…

Gallium cannot be produced at scale because it does not form concentrated ores in nature. It cannot be usefully mined directly. The only reason it is relatively inexpensive is that there is limited demand for the minuscule quantities that are currently produced.

Gallium is currently supplied by reprocessing the waste from other convenient metal ores to extract the traces of gallium. Even if we maximized gallium extraction from these waste streams, we are talking about a few thousand tons of gallium per year. We produce more gold every year than there is practically available gallium.

Unfortunately this is the story with many proposed solutions to carbon capture. Many things are possible as a prototype which are completely infeasible at the industrial scales required to make a dent in atmospheric carbon because the resources don't exist to run chemistry at that scale.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#85

Post by halaahmed » Sat, Oct 23, 2021, 3:56 PM UTC

I get how you could use this to take solar energy and pull CO2 out of the air, but the article mentions using it in cars, which makes no sense. You’re going to use more energy than you get from burning gas to then capture the carbon?

Re: Gallium helps convert CO2 into Carbon and Oxygen

#86

Post by sabujp » Sat, Oct 23, 2021, 3:57 PM UTC

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…

does the semiconductor industry not use large quantities of GaAs? Has the industry replaced its use with something else? https://en.wikipedia.org/wiki/Gallium_arsenide

Re: Gallium helps convert CO2 into Carbon and Oxygen

#87

Post by [deleted] » Sat, Oct 23, 2021, 4:03 PM UTC

[deleted]

Re: Gallium helps convert CO2 into Carbon and Oxygen

#88

Post by pjc50 » Sat, Oct 23, 2021, 4:03 PM UTC

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…

> people will end up driving more because of the lower marginal costs.

I suspect places will have to move to either London-style congestion charges or milage-based road taxes to offset this. With an admittedly big loss of privacy, you could even price at the level of individual roads and put Uber-style surge pricing on the roads themselves.

Another possibility is that the "markets in everything" self-driving companies win and cars become a capital asset that can work itself. No reason to drive your car around uselessly if you can rent it out instead, and in theory this could result in fewer cars. However I'm skeptical.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#89

Post by BurningFrog » Sat, Oct 23, 2021, 4:06 PM UTC

ineedasername wrote: post #72

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…

don't believe altruism will solve greenhouse gas emissions and global warming: it'll only be solved when it becomes economic to do so. You've listed altruism and economics, but may have discounted self-interest-- not financial, but survival. Young adults especially are both at an age where they can expect to feel some especially nasty impacts of climate change, and at a point in their career where they can begin maki…

Global climate change is not something one person or family can affect, so I don't understand what form of self-interest driven action could impact it.

BTW, the "economic" solution consists of making it in everyone's self interest to work against CO₂ emissions.

Re: Gallium helps convert CO2 into Carbon and Oxygen

#90

Post by credit_guy » Sat, Oct 23, 2021, 4:15 PM UTC

nkingsy wrote: post #64

credit_guy wrote: post #50

Earlier quoted context omitted.

> This is an important sanity check You have a bug somewhere, I'm not sure where. Roughly speaking the heat of combustion is proportional to the number of atoms of oxygen in the molecules coming out of the reaction. So CH4 + 2 O2 = CO2 + 2 H20 If you hypothetically split CH4 first, you get CH4 + 2 O2 = (C + 2 H2) + 2 O2 = (C + O2) + (2 H2 + O2) = CO2 + 2H20 The first reaction is endothermic, but it absorbs much less…

The article clearly states a claimed 92% efficiency.

Good point. But there are two problems with that claim.

One is about an order a magnitude, the other about a sign.

The first one: if you burn 1kg of pure Carbon, you get 3.67 kg of CO2 and 32.8 MegaJoules [1], which is the same as 32800 kJ or, 32800/3600 kWh. That's 9.11 kWh for each 3.67 kg of CO2, or 2.4848 kWh/kg. That's quite close to 2500 kWh/ton.

They are claiming it takes them 230 kWh/ton to reverse this reaction. You can see this is an order of magnitude wrong. Let's say they meant to say 2300 kWh/ton. If you divide that by 2500 kWh/ton you get exactly 92% that they claim.

But here's the second mistake: you need to put more, not less energy to split CO2, otherwise you'd get energy for free. 2300 kWh/ton is simply impossible. You need to use more than that, and actually more than 2500 kWh/ton if you don't want to violate the first principle of thermodynamics.

[1] https://en.wikipedia.org/wiki/Heat_of_combustion#Heat_of_com...