I’ve come across numerous articles claiming the Industrial Process requiring high temperatures are not able to be powered by renewable energy. Is this true?

Below is an example of such an article.

Whither energy?

by Pondy001

10 comments

  1. Not rly. There are several huge steel companies who are working on solution

  2. …this is literally going to be the only true ‘ round ball in the round hole’ hydrogen application as I understand it.

  4. I didn’t read the entire thing because it’s painful.
    But I did search for the part you cared.

    > Electrical systems melt down at temperatures far below what is necessary to produce glass, for example. But even within the range of possibility, electrical heat generation is energetically and economically expensive — it takes a lot of pricey electricity to run a heat pump.

    Yeah.. like if anyone is going to try and make glass melting temperatures using heat pump. Industrial heat is roughly splitted into 3 chunks. Low, between 30 and 150 for food, medical, fabric. Medium between 150 and 400 for chemical processing and refinery. And high which is anything above.

    The low range can be easily supplied by a industrial heat pump. Up to the low end of medium is doiable with a heat pump. And can be stored easily.

    Medium is more difficult. But solutions like heat battery are aiming to solve this issue. The idea being to store heat as hot bricks, and then extract the heat for use later on. And only ‘charge’ it by heating back up when there’s plenty of renewables. This process is by definition 100% efficient (except heat loss to the environment).

    High heat above a few hundred is more difficult. This is where green hydrogen actually makes sense. The flame reachs 1000 degrees and is being used to make green steel now. Scaling up is needed .

    Source: https://youtu.be/Z2NBbJX-cGM

  6. “Renewable energy” is pretty broad, it also depends on the industry.

    Some steel plants us electric arc furnaces. Those can be renewable, but that’s not helpful in cement.

    Electric boilers can generate steam, but can be costly.
    Heat pumps have no problem with heat up to 90C, getting up to around 140C is possible and not uncommon in Europe, less so in north America. Over that is still research.

    High temps can be achieved with combustion, and those combustion fuels could be replaced with renewable combustion fuels like green hydrogen or biogas. But that’s not a broadly available option right now.
        
    Tl;DR: industrial processes could definitely be powered by renewable energy in some form, it’s just not all commercially available now.

  9. This is an article with very low understanding. It seems to imply that heat pumps are the only option when they are not even very frequently considered.

    Electric arc furnaces are not only capable of achieving those temperatures, they are the dominant form of high temperature melting furnace including for glass, though more notably for metallurgy. Electrical systems at those temperatures do not “break down” but there is manageable attrition of the electrodes in the range of a few kilos per ton melted, and all of the heat is concentrated in the crucible.

    While there are oxyfuel alternatives for those temperature ranges, if you require temperatures still higher, electricity is the only option through the use of thermal plasma. See, for example, methane pyrolysis. There are also a large number of high temperature processes that are electrical for reasons that are not solely for heat, for example in the electrowinning of aluminum from cryolite that typically takes place around 950C which is the source of all the world’s primary aluminum.

    Someone here mentioned steel. Electric Arc furnaces are the world’s best available method for producing steel from scrap; the issue with primary steel production is not that electric systems are unable to handle them, but that primary smelting of ores as it currently operates in blast furnaces requires carbon as a reducing agent and not merely as a source of heat; replacing it is a matter of redesigning the processes around replacing the chemical reducing agent. Temperatures are not the issue.

    For all of these, electricity is not only a viable means of achieving temperature, but the dominant and preferred one. Where there is some legitimate concern is that (1) a large number of processes operate below the 1000C range where electricity becomes your best option and well above the level where it is currently viable to use something like process heat pumps, and (2) electricity is much better at transferring heat to solids or liquids than it is to gases. Thus the technical capability in current practice is eclipsed by lack of economic viability for a lot of direct and indirect applications in the 300-1000C range that traditionally rely on radiant hot gas like boilers or steam cracking.

    There are ways of working around these technical issues, and they are still work in progress, but by no means are these insurmountable. No less a company than Haldor Topsøe is now licensing electrically heated steam reforming furnaces. There are multiple pilot projects ongoing for steam cracking up to and including the bizarre Siemens-Technip rotary cracker that is all-electric.

    Basically, if this is what “most people know” as that link claims, then I feel a lot better about my expertise.

  10. It’s a bit of an… ignorant? nontechnical? article. The problems with electrifying industrial heat completely revolve around economics. It’s possible to generate any temperature with electricity, using technology which is just as affordable as combustion. In fact, in most cases, electrical heat is preferrable because it doesn’t introduce exhaust gases of any kind.

    But: gas is about 10x cheaper than electricity, joule for joule. This can be partially counteracted using heat pumps, a large-capacity heat pump can get pretty close to theoretical efficiency and only be ~2X more expensive than gas.

    But heat pumps only work for small temperature differences. The larger the temperature difference, the less efficacious they become, and beyond a 2:1 (absolute) temperature differential, even multistage heat pumps aren’t economical anymore. So you have to provide heat directly, using e.g. incandescence, arc discharge or induction. All of these can provide arbitrarily high temperatures, but they don’t offer any efficiency improvements. Especially if your electricity is already derived from fossil fuels, they’re objectively more polluting than just using those fuels directly. And for the kind of process that we’re talking about (industrial metal production, cement, etc.), that’s often the case. So electrification will only work with very abundant, very cheap electricity and/or very high fossil fuel prices.

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