9 ms·

Solar furnace to melt steel at 2000°C for Swiss recycler

smm11 4y ago
Thermodynamics, blah, blah. Buncha' people no doubt fun at parties.
baseline-shift 4y ago
To decarbonize heavy industry, highly concentrated solar thermal is the best option. Heat is the form of energy most responsible for carbon emissions in industries like steel and cement. Solar thermal (duh) generates heat from thousands of "suns" of sunlight.
- Xylakant 4y ago
  Solar may replace the heat component in some applications (as in this one), but in refining steel the carbon is required for the chemical process - it binds the oxygen from the iron. Carbon in that application can be replaced by hydrogen, but it can’t be just replaced by another heat source.
  - vba616 4y ago
    How is that carbon emissions? It sounds like carbon absorbed?
    - marcosdumay 4y ago
      You push a lot of carbon into the iron, most react with oxygen and go away as CO2. So the entire process emits CO2, and absorb pure carbon (usually from oil).
    - JumpCrisscross 4y ago
      > How is that carbon emissions? In goes iron ore, a mix of iron oxides and carbon, out comes iron and carbon oxides. The carbon moved from the ore to the atmosphere.
      - tkanarsky 4y ago
        So if I recall correctly from HS chem, iron is being reduced in this case by the carbon in the coke. From a cursory glance at the electronegativity table, iron is at 1.83, carbon's at 2.5 and hydrogen is 2.1. Higher electronegativity = more attractive to electrons = better reducing agent so hydrogen will reduce iron but less efficiently? than carbon. I don't know if this means that more energy is required to get the hydrogen to reduce carbon, or if the reaction will just be slower, but the upside is that the only byproduct of this process is pure H2O.
  - marcosdumay 4y ago
    You can reduce iron by electrolysis, where you vent oxygen instead of CO2 or water. You'll just need a higher temperature and some quite robust electrodes (both of what are currently expensive). What you just can't do is replace the carbon that is added into the steel. The process will always need a carbon source.
- marcosdumay 4y ago
  CSP is way more efficient than photovoltaics, but electricity is much more flexible and easier to control than heat. I'll not be surprised if the industry decides to waste 70% of the energy and go with photovoltaics.
  - kardos 4y ago
    That, or there will be an optimal mixture. Eg, CSP may be akin to baseload and you'd draw from the grid for the rest
random3 4y ago
That looks like something from the future and the photo made me remember the Dune II windtaps - https://strategywiki.org/wiki/File:Dune_II_wind_trap.jpg https://strategywiki.org/wiki/File:Dune_II_wind_trap.jpg
rr888 4y ago
Much of the heavy industry in the future is likely to be in deserts near the equator.
- SoftTalker 4y ago
  Which would be nice except people don't live there, so they'd have to pay a premium to workers to relocate and live in an equatorial desert, as well as transport in all the food, water, and housing that they will need. Sort of like ocean oil platform workers.
  - rr888 4y ago
    Middle East already has a lot of workers from Asia. People follow the money, if the works is there the people will follow. The biggest problem is if it gets too hot to be able to live.
  - monkmartinez 4y ago
    I live in a big, hot desert with millions of others right here in the USA. We are ready for this tech. Intel and TSMC think this desert is pretty awesome, as do I.
  - hammock 4y ago
    Sort of like Dubai, Abu Dhabi, Phoenix, Las Vegas? It has worked for the those places.
teruakohatu 4y ago
> The solar furnace could melt up to 400 tons of recycled steel each year. This is very little, it's about the amount of steel used in 450 cars. My tiny country with 5 million people (New Zealand) recycles 300,000 tonnes of steel per year.
- cjrp 4y ago
  They're a "wristwatch component manufacturer"; so presumably they need much smaller quantities than a car manufacturer.
jcampbell1 4y ago
I’d be willing to bet this design is more expensive than solar panels and using an electric furnace which is common for recycling steel. You still need some way to deal with rust, and carbon electrodes work great. Steel is roughly $500 per ton, so they are looking at $200k a year in revenue. This is a cool research project, but the economics are not realistic anytime soon.
- xupybd 4y ago
  Yeah but the site already existed. So it's a very cheap way to test the idea.
michael_j_ward 4y ago
Do I have this Napkin math correct? 400 tons produced per year (original article) $1000 per ton (generous [0], current index at $770) $400k per year revenue (calculated) $25M Euro investment (original article) ~63 years payback on *revenue* (being generous again with EURSD=$1) Do I have that right? [0] https://www.cmegroup.com/markets/metals/ferrous/hrc-steel.html https://www.cmegroup.com/markets/metals/ferrous/hrc-steel.ht...
- acchow 4y ago
  Plus revenue from selling carbon credits. I don't know the value of that.
- jseutter 4y ago
  You have the math right, but the product wrong. They are looking for specific types of steel that are currently unavailable at almost any price. Their order size is too small to warrant returning a phone call from normal steel producers. Certain types of tool steel that are currently available sell for upwards of $3000/ton, but the type of steel they need is no longer a commodity, so the price is likely even higher. They have 50 tons of scrap steel that is exactly what they need, but need a spot to melt it down for reuse. You can't (partially guessing here) just throw it in an existing smeltery while maintaining its purity. They have been collecting this scrap by talking to other users that also use the same material. The article mentions they are in the Jura Arc. I didn't know this, but that is a reference to the watchmakers valley in Switzerland. If you're selling a $60k watch, it better be made from 99.999999% pure unobtanium. I have seen similar situations before where when you start making a niche product, suddenly demand pops out of the background that wasn't there before because the product simply wasn't available. Even if it isn't profitable from day 1 it might eventually become profitable.
  - jsnell 4y ago
    Are you sure about that "unavailable at almost any price" part? Their initial inputs seem to be be the scraps produced by the local manufacturers in a relatively tiny area over the last few years. If this grade of steel wasn't available, where did all these local manufacturers get a constant supply from? (I.e. there has to be an existing and supplied market, it's not like they're recycling the steel only from the scuttled German battleships in Scapa Flow or something.) The use cases are quoted as "watchmaking and medical subcontracting", fwiw.
sfe22 4y ago
I always wondered why not use a system like this to heat water and use turbine to generate electricity. Shouldn’t this get much higher output efficiency compared to pv panels.
- nerdawson 4y ago
  Systems like that already exist. They’re known as Concentrated Solar Power: https://en.m.wikipedia.org/wiki/Concentrated_solar_power https://en.m.wikipedia.org/wiki/Concentrated_solar_power
  - sfe22 4y ago
    Thanks, that is awesome.
    - danans 4y ago
      The problem is that it's more expensive on a levelized cost of energy basis than solar and wind. It might be more competitive if it can be paired with thermal storage, but AFAIK that's not demonstrates at scale yet.
      - baseline-shift 4y ago
        The thermal energy storage aspect of CSP is how the heat is accessed to run the power block - it not paired with- like some kind of bolt-on extra - is definitely demonstrated at scale. Just not in the US, which only tried out 5 CSP plants, only 2 with storage. China is currently building 30 CSP plants - all with storage. Here's how thermal energy storage in CSP works https://www.solarpaces.org/how-csp-thermal-energy-storage-works/ https://www.solarpaces.org/how-csp-thermal-energy-storage-wo...
      - airbreather 4y ago
        The break even point might be near, currently every mirror is controlled by an open loop controller of some sophistocation to point exactly right relative to the sun, time of day and tower. But the CSIRO has a system where a camera looks at the mirrors from the tower and estimates quite well the mirror angle from the shade of blue reflected. This makes it closed loop control, one sensor for many mirrors and simple actuation like lead screw with raise/lower controls possible.
deleted 4y ago
[deleted]
recycledmatt 4y ago
As someone in the recycling supply chain, this is incredibly cool. The possible carbon reduction emissions are massive. This would need to scale up by factors of 100 (400 tons a year is nothing- a single sea borne cargo that is traded is often 32-40000 tons), but amazing to see the cutting edge.

Thermodynamics, blah, blah. Buncha' people no doubt fun at parties.

To decarbonize heavy industry, highly concentrated solar thermal is the best option. Heat is the form of energy most responsible for carbon emissions in industries like steel and cement. Solar thermal (duh) generates heat from thousands of "suns" of sunlight.

Xylakant 4y ago
Solar may replace the heat component in some applications (as in this one), but in refining steel the carbon is required for the chemical process - it binds the oxygen from the iron. Carbon in that application can be replaced by hydrogen, but it can’t be just replaced by another heat source.
- vba616 4y ago
  How is that carbon emissions? It sounds like carbon absorbed?
  - marcosdumay 4y ago
    You push a lot of carbon into the iron, most react with oxygen and go away as CO2. So the entire process emits CO2, and absorb pure carbon (usually from oil).
  - JumpCrisscross 4y ago
    > How is that carbon emissions? In goes iron ore, a mix of iron oxides and carbon, out comes iron and carbon oxides. The carbon moved from the ore to the atmosphere.
    - tkanarsky 4y ago
      So if I recall correctly from HS chem, iron is being reduced in this case by the carbon in the coke. From a cursory glance at the electronegativity table, iron is at 1.83, carbon's at 2.5 and hydrogen is 2.1. Higher electronegativity = more attractive to electrons = better reducing agent so hydrogen will reduce iron but less efficiently? than carbon. I don't know if this means that more energy is required to get the hydrogen to reduce carbon, or if the reaction will just be slower, but the upside is that the only byproduct of this process is pure H2O.
- marcosdumay 4y ago
  You can reduce iron by electrolysis, where you vent oxygen instead of CO2 or water. You'll just need a higher temperature and some quite robust electrodes (both of what are currently expensive). What you just can't do is replace the carbon that is added into the steel. The process will always need a carbon source.
marcosdumay 4y ago
CSP is way more efficient than photovoltaics, but electricity is much more flexible and easier to control than heat. I'll not be surprised if the industry decides to waste 70% of the energy and go with photovoltaics.
- kardos 4y ago
  That, or there will be an optimal mixture. Eg, CSP may be akin to baseload and you'd draw from the grid for the rest

random3 4y ago

That looks like something from the future and the photo made me remember the Dune II windtaps - https://strategywiki.org/wiki/File:Dune_II_wind_trap.jpg https://strategywiki.org/wiki/File:Dune_II_wind_trap.jpg

rr888 4y ago

Much of the heavy industry in the future is likely to be in deserts near the equator.

SoftTalker 4y ago
Which would be nice except people don't live there, so they'd have to pay a premium to workers to relocate and live in an equatorial desert, as well as transport in all the food, water, and housing that they will need. Sort of like ocean oil platform workers.
- rr888 4y ago
  Middle East already has a lot of workers from Asia. People follow the money, if the works is there the people will follow. The biggest problem is if it gets too hot to be able to live.
- monkmartinez 4y ago
  I live in a big, hot desert with millions of others right here in the USA. We are ready for this tech. Intel and TSMC think this desert is pretty awesome, as do I.
- hammock 4y ago
  Sort of like Dubai, Abu Dhabi, Phoenix, Las Vegas? It has worked for the those places.

teruakohatu 4y ago

> The solar furnace could melt up to 400 tons of recycled steel each year. This is very little, it's about the amount of steel used in 450 cars. My tiny country with 5 million people (New Zealand) recycles 300,000 tonnes of steel per year.

cjrp 4y ago
They're a "wristwatch component manufacturer"; so presumably they need much smaller quantities than a car manufacturer.

jcampbell1 4y ago

I’d be willing to bet this design is more expensive than solar panels and using an electric furnace which is common for recycling steel. You still need some way to deal with rust, and carbon electrodes work great. Steel is roughly $500 per ton, so they are looking at $200k a year in revenue. This is a cool research project, but the economics are not realistic anytime soon.

xupybd 4y ago
Yeah but the site already existed. So it's a very cheap way to test the idea.

michael_j_ward 4y ago

Do I have this Napkin math correct? 400 tons produced per year (original article) $1000 per ton (generous [0], current index at $770) $400k per year revenue (calculated) $25M Euro investment (original article) ~63 years payback on *revenue* (being generous again with EURSD=$1) Do I have that right? [0] https://www.cmegroup.com/markets/metals/ferrous/hrc-steel.html https://www.cmegroup.com/markets/metals/ferrous/hrc-steel.ht...

acchow 4y ago
Plus revenue from selling carbon credits. I don't know the value of that.
jseutter 4y ago
You have the math right, but the product wrong. They are looking for specific types of steel that are currently unavailable at almost any price. Their order size is too small to warrant returning a phone call from normal steel producers. Certain types of tool steel that are currently available sell for upwards of $3000/ton, but the type of steel they need is no longer a commodity, so the price is likely even higher. They have 50 tons of scrap steel that is exactly what they need, but need a spot to melt it down for reuse. You can't (partially guessing here) just throw it in an existing smeltery while maintaining its purity. They have been collecting this scrap by talking to other users that also use the same material. The article mentions they are in the Jura Arc. I didn't know this, but that is a reference to the watchmakers valley in Switzerland. If you're selling a $60k watch, it better be made from 99.999999% pure unobtanium. I have seen similar situations before where when you start making a niche product, suddenly demand pops out of the background that wasn't there before because the product simply wasn't available. Even if it isn't profitable from day 1 it might eventually become profitable.
- jsnell 4y ago
  Are you sure about that "unavailable at almost any price" part? Their initial inputs seem to be be the scraps produced by the local manufacturers in a relatively tiny area over the last few years. If this grade of steel wasn't available, where did all these local manufacturers get a constant supply from? (I.e. there has to be an existing and supplied market, it's not like they're recycling the steel only from the scuttled German battleships in Scapa Flow or something.) The use cases are quoted as "watchmaking and medical subcontracting", fwiw.

sfe22 4y ago

I always wondered why not use a system like this to heat water and use turbine to generate electricity. Shouldn’t this get much higher output efficiency compared to pv panels.

nerdawson 4y ago
Systems like that already exist. They’re known as Concentrated Solar Power: https://en.m.wikipedia.org/wiki/Concentrated_solar_power https://en.m.wikipedia.org/wiki/Concentrated_solar_power
- sfe22 4y ago
  Thanks, that is awesome.
  - danans 4y ago
    The problem is that it's more expensive on a levelized cost of energy basis than solar and wind. It might be more competitive if it can be paired with thermal storage, but AFAIK that's not demonstrates at scale yet.
    - baseline-shift 4y ago
      The thermal energy storage aspect of CSP is how the heat is accessed to run the power block - it not paired with- like some kind of bolt-on extra - is definitely demonstrated at scale. Just not in the US, which only tried out 5 CSP plants, only 2 with storage. China is currently building 30 CSP plants - all with storage. Here's how thermal energy storage in CSP works https://www.solarpaces.org/how-csp-thermal-energy-storage-works/ https://www.solarpaces.org/how-csp-thermal-energy-storage-wo...
    - airbreather 4y ago
      The break even point might be near, currently every mirror is controlled by an open loop controller of some sophistocation to point exactly right relative to the sun, time of day and tower. But the CSIRO has a system where a camera looks at the mirrors from the tower and estimates quite well the mirror angle from the shade of blue reflected. This makes it closed loop control, one sensor for many mirrors and simple actuation like lead screw with raise/lower controls possible.

deleted 4y ago

[deleted]

recycledmatt 4y ago

As someone in the recycling supply chain, this is incredibly cool. The possible carbon reduction emissions are massive. This would need to scale up by factors of 100 (400 tons a year is nothing- a single sea borne cargo that is traded is often 32-40000 tons), but amazing to see the cutting edge.