4 ms·

Your cited link does not seem to support your assertion that you must "melt coal with quartz". I do not believe that's correct. The general idea you are referr

Your cited link does not seem to support your assertion that you must "melt coal with quartz". I do not believe that's correct. The general idea you are referring to is the "life cycle greenhouse gas emissions" for an energy technology. This is a well studied field. Information from the IPCC and the DOE seems to indicate that photovoltaics and wind have something like 20 times lower green house gas emissions than coal plants over the entire life cycle. [1][2] And since the manufacture of PV and wind accounts for a majority of the greenhouse gas emissions associated with the lifecycle, the emissions will improve for this tech as the blend of energy used to power the manufacturing becomes "greener". If you think that renewables "aren't even replacing the amount of energy demand is growing by", then you should advocate for additional construction of renewable energy rather than suggesting that they are a dirty technology—since the science we have suggests they are not. [1] https://en.wikipedia.org/wiki/Life-cycle_greenhouse-gas_emissions_of_energy_sources https://en.wikipedia.org/wiki/Life-cycle_greenhouse-gas_emis... [2] https://www.nrel.gov/analysis/life-cycle-assessment.html https://www.nrel.gov/analysis/life-cycle-assessment.html

diogenescynic 6y ago
It’s used in the reaction process with the quartz: >silicon metal is made from the reaction of silica and carbon materials like coke, coal and wood chips https://www.workoutmilano.it/gold2/6774-silicon-metal-quartz-woodchip-coal.html https://www.workoutmilano.it/gold2/6774-silicon-metal-quartz... > In order to produce a single (1) metric ton (MT) of silicon metal, raw material inputs of 2.8 MT quartz, 1.4 MT coal, and 2.4 MT wood chips are required and represent a 6.6:1 ratio of process inputs to outputs. http://guntherportfolio.com/2010/03/making-silicon-metal-for-solar/ http://guntherportfolio.com/2010/03/making-silicon-metal-for...
- skissane 6y ago
  Converting silicon dioxide to elemental silicon is usually done by reacting with carbon, which produces carbon dioxide as a waste gas. However, in principle, the carbon dioxide could be captured and even recycled back into carbon to reuse in the initial reaction. I don’t think this is being done yet (at least not on a commercial scale), but there is no reason in principle why we couldn’t develop such a technology and combine it with nuclear/renewable power sources to reduce greenhouse gas emissions and fossil fuel consumption due to silicon refining to zero.
  - diogenescynic 6y ago
    Yes, but today we’re using coal to produce solar panels. Why even bother with such a fantasy hypothetical? Why not just go all the way to cold fusion if we’re just making stuff up that isn’t being done currently? This is what I meant about the left having a fantasy that one day technology will save us. We just cannot accept reality.
    - skissane 6y ago
      > Yes, but today we’re using coal to produce solar panels. Why even bother with such a fantasy hypothetical? Why not just go all the way to cold fusion if we’re just making stuff up that isn’t being done currently? One obvious difference – the technology to capture waste CO2 gas is clearly feasible in principle. We already have lots of research into capturing and reusing CO2 (such as from coal-fired power stations) [1], and we already have known industrial processes which use CO2 as input [2]. So, the issue here is really (a) more R&D to finesse the technology, (b) its application to silicon refining specifically (other CO2 emissions sources are more significant and hence receive more focus) (c) getting the economics right. (On the last point, emissions trading schemes may help.) By contrast, most of the physics community doesn't believe cold fusion is a real phenomena, and the small minority who think it is can't explain how it works. You are comparing a technology whose physics and chemistry is well understood, and which basically just needs productisation, with a technology where there is disagreement on whether physics even allows it to exist. [3] seems a particularly interesting approach - conversion of CO2 gas to graphite. The graphite in turn could potentially be reused in the silicon refining (which needs a carbon source, not coal/coke/wood specifically). Most current methods of procesing CO2 turn it into chemicals such as methanol (CO2 + hydrogen gas), urea (CO2 + ammonia), etc, which while useful, I'm not sure you could actually reuse those chemicals in silicon refining [1] https://en.wikipedia.org/wiki/Carbon_capture_and_storage https://en.wikipedia.org/wiki/Carbon_capture_and_storage [2] e.g. https://en.wikipedia.org/wiki/Methanol#From_synthesis_gas https://en.wikipedia.org/wiki/Methanol#From_synthesis_gas [3] https://www.nature.com/articles/s41467-019-08824-8 https://www.nature.com/articles/s41467-019-08824-8 > This is what I meant about the left having a fantasy that one day technology will save us I'm not sure it is really "the left having a fantasy". I know plenty of right-leaning people with solar panels on their roofs. (I even know global warming sceptics with solar panels on their roof.)

diogenescynic 6y ago

It’s used in the reaction process with the quartz: >silicon metal is made from the reaction of silica and carbon materials like coke, coal and wood chips https://www.workoutmilano.it/gold2/6774-silicon-metal-quartz-woodchip-coal.html https://www.workoutmilano.it/gold2/6774-silicon-metal-quartz... > In order to produce a single (1) metric ton (MT) of silicon metal, raw material inputs of 2.8 MT quartz, 1.4 MT coal, and 2.4 MT wood chips are required and represent a 6.6:1 ratio of process inputs to outputs. http://guntherportfolio.com/2010/03/making-silicon-metal-for-solar/ http://guntherportfolio.com/2010/03/making-silicon-metal-for...

skissane 6y ago
Converting silicon dioxide to elemental silicon is usually done by reacting with carbon, which produces carbon dioxide as a waste gas. However, in principle, the carbon dioxide could be captured and even recycled back into carbon to reuse in the initial reaction. I don’t think this is being done yet (at least not on a commercial scale), but there is no reason in principle why we couldn’t develop such a technology and combine it with nuclear/renewable power sources to reduce greenhouse gas emissions and fossil fuel consumption due to silicon refining to zero.
- diogenescynic 6y ago
  Yes, but today we’re using coal to produce solar panels. Why even bother with such a fantasy hypothetical? Why not just go all the way to cold fusion if we’re just making stuff up that isn’t being done currently? This is what I meant about the left having a fantasy that one day technology will save us. We just cannot accept reality.
  - skissane 6y ago
    > Yes, but today we’re using coal to produce solar panels. Why even bother with such a fantasy hypothetical? Why not just go all the way to cold fusion if we’re just making stuff up that isn’t being done currently? One obvious difference – the technology to capture waste CO2 gas is clearly feasible in principle. We already have lots of research into capturing and reusing CO2 (such as from coal-fired power stations) [1], and we already have known industrial processes which use CO2 as input [2]. So, the issue here is really (a) more R&D to finesse the technology, (b) its application to silicon refining specifically (other CO2 emissions sources are more significant and hence receive more focus) (c) getting the economics right. (On the last point, emissions trading schemes may help.) By contrast, most of the physics community doesn't believe cold fusion is a real phenomena, and the small minority who think it is can't explain how it works. You are comparing a technology whose physics and chemistry is well understood, and which basically just needs productisation, with a technology where there is disagreement on whether physics even allows it to exist. [3] seems a particularly interesting approach - conversion of CO2 gas to graphite. The graphite in turn could potentially be reused in the silicon refining (which needs a carbon source, not coal/coke/wood specifically). Most current methods of procesing CO2 turn it into chemicals such as methanol (CO2 + hydrogen gas), urea (CO2 + ammonia), etc, which while useful, I'm not sure you could actually reuse those chemicals in silicon refining [1] https://en.wikipedia.org/wiki/Carbon_capture_and_storage https://en.wikipedia.org/wiki/Carbon_capture_and_storage [2] e.g. https://en.wikipedia.org/wiki/Methanol#From_synthesis_gas https://en.wikipedia.org/wiki/Methanol#From_synthesis_gas [3] https://www.nature.com/articles/s41467-019-08824-8 https://www.nature.com/articles/s41467-019-08824-8 > This is what I meant about the left having a fantasy that one day technology will save us I'm not sure it is really "the left having a fantasy". I know plenty of right-leaning people with solar panels on their roofs. (I even know global warming sceptics with solar panels on their roof.)