[alexey-salmin]

> If you could get the price down to $100/ton

That is the price of a ton of coal. Buy it from China BEFORE it gets burned and you have a sensible strategy.

Sucking it back from the atmosphere AFTER burning takes 10x more energy which is complete insanity. "Getting price down" and "when it scales" is an utter misunderstanding of the situation. Scale doesn't defeat the laws of physics.

[gersh]

So long as they have coal power plants, and need the electricity unless it get prohibitively expensive, they will just mine more coal. The way to reduce emissions is to replace high-emission infrastructure.

[rayiner]

The political and logistical problems are a far bigger challenge than energy production. Just think of all the concrete that China and India will need to pour in the coming decades and the CO2 emissions of that.

[alexey-salmin]

No. If cheap energy production wasn't a huge challenge we wouldn't have the CO2 challenge either. It is the same challenge essentially. You can say it's "96% the same challenge" if you want to take concrete into equation.

No politics or logistics can change laws of physics. Burning coal with hand and capturing it with the other at 10x the cost just doesn't make sense, neither from the engineering perspective nor from the economical.

[yurishimo]

I saw a graph of that the other day and supposedly concrete was only about 3% of emissions globally.

Even if India and China triple that, we’re still coming out ahead by focusing on the reduction of fossil fuels for power generation, international transport, and heating buildings.

[pietro72ohboy]

Why should anyone stop China and India from making lives better for their people? Seems like the classic American mindset where they get to pour as much concrete as they’d like but when other countries try to do it, they start talking of the environment.

[Dylan16807]

> That is the price of a ton of coal. Buy it from China BEFORE it gets burned

And then that money funds more mines to get coal out of the ground faster.

> Sucking it back from the atmosphere AFTER burning takes 10x more energy which is complete insanity.

Part of the plan needs to be capture at power plants. Another part of the plan needs to be heavy taxes for releasing CO2. If someone needs the convenience for some use case, let them pay the capture price.

[alexey-salmin]

> Part of the plan needs to be capture at power plants.

You realize that this makes power plants energy-negative?

[Dylan16807]

No it doesn't. You're not turning it back into fuel. You need to bottle it up or react it into a non-gas, both of which use much less energy than you get from combustion.

[alexey-salmin]

Well try to write down a concrete chemical reaction to achieve this and you will be disappointed. Light atoms like carbon don't like to stay close to each other at room temperature. You need to pour a lot of energy into chemical bonds between them to make that happen.

So no, it's still an energy-bound problem and we still burn coal to get energy.

[Dylan16807]

One of the options is just injecting CO2 into very deep caves/water. And it will then react with many rocks all by itself!

The company that Microsoft is buying capture from is using lots of energy to remove CO2 from rocks, but that's because they're working to pull more CO2 from normal air. When you have an exhaust pipe it's already concentrated and you can separate it out much more easily.

[alexey-salmin]

Injection of CO2 into water happens naturally in the ocean. Unfortunately ocean didn't respond to any of the VC calls.

Injecting CO2 into rocks "all by itself" is extremely slow because it's exothermic and because surface of rocks is too small. You need to crush the rocks (energy) and heat them up (energy).