Don’t we use coal for two main things? Energy and steel?
Do we have a replacement for coal in the steel industry?
Do we have a replacement for coal in the steel industry?
translation> It had 15,000 ha of forest with 30 million eucalyptus trees to extract the coal necessary in the process, for which the town of "Centro Forestal" was build.
Also, coal we dig up is much more suitable for one or the other purpose. If you mine thermal coal, the steel plant doesn't want it, they want metallurgical coal. If your country has a steel plant, and a thermal coal mine, you will export thermal coal from the mine and import metallurgical coal to run the steel plant. Well, if nobody buys your thermal coal, the coal mine shuts, even if you still have a steel plant.
3.5 kwh/kg is probably 20 cents worth of electricity.
[1] Separators are used to isolate the anode and cathode in electrolytic cells in order to suppress side reactions. Modern separators allow specific ions to pass while blocking others.
Your phrasing implies this is a small number - but 20 cents per kg is 20000c/tonne or $200 per tonne. The current spot price for iron ore is $200, which itself is twice as much as it was a year ago. So the additional cost of electricity could take the spot price as high as $400, four times as much as it was in July 2020.
It's still an important for the environment to do this & remove carbon from the industry, but need to acknowledge the costs.
My thinking is electrowinning iron and mini-mills could easily absorb excess capacity. Aqueous electrolytic cells should be able to just sit idle for hours to days. And electric furnaces draw easily 10-100MW. That makes them a good match for a renewable grid.
Low-carbon alternatives to Portland cement are being researched and piloted, too. Just a matter of money and the learning curve, the same as with electric power production.
Further, nuclear is simply not a good option for this application. Cement kilns need to reach 1,450 C, while reactor temperatures are limited to about 950 C.
Isn't this irrelevant?
It's not like we just produce cement to stockpile it indefinitely. When it's mixed with water and used to construct useful things, that CO2 comes back out of the atmosphere as it "cures".
What am I missing here?
The cement doesn't turn 100% back into calcium carbonate. Only the surface of the grains get exposed to the water and CO2 necessary to cure.
Still in R&D admittedly, but micronuclear should do the job well.
No research is going to replace the carbon in steel with something clean, your article is about the energy used in steel production and not the elemental carbon going into the steel itself.
Is that what you meant to say? How is carbon in steel not "clean"?