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Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

onlinelibrary.wiley.com

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Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#21

Post by twawaaay »

Robotbeat wrote: post #2

I don’t get this. We already use direct reduction using about half hydrogen, and that can be increased to over 90%. Producing ammonia via the Haber process means losing 40% or so of the energy (and potentially more as you convert it back), so why not just use hydrogen directly? Simply because moving hydrogen is harder than ammonia? I think it makes way more sense to just make and use the hydrogen on-site.

I also think so. Rather than move hydrogen, move the electricity or the iron. Produce hydrogen on site and even on demand to get rid of most of the need to store/transport it.

As to cost, who can quantify me the risks of having and transporting so much ammonia?

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#22

Post by rainbowzootsuit »

ClumsyPilot wrote: post #20
philipkglass wrote: post #6

Earlier quoted context omitted.

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

Exactly, I struggle to see any situation, barring mismanagement or disaster, where you should be shipping tankers full of hydrogen byproducts like ammonia and losing most of the energy in the process. We are currently importing all the natural gas in Europe, and both the price and carbon footrpint are more than double of what pipeline delivered from Russia. You could build a pipeline from the middle east to Europe fo…

Hydrogen, being so small, penetrates directly through the molecular structure of steel and in the process causes embrittlement of the steel. Is a long distance H2 pipeline a solved problem using alternate materials?

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#24

Post by KMag »

philipkglass wrote: post #6
PaulHoule wrote: post #4

Earlier quoted context omitted.

i think the question is how far you are shipping the hydrogen. If, say, people are making hydrogen in (say) the Middle East and shipping it to (say) Europe then the overhead of liquifying or compressing H2 is on the same order as converting to ammonia. In that paper they demonstrate that you can just use the ammonia directly to reduce iron and not have a separate system to convert it back. If you have a big wind powe…

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

But the mass of the extracted oxygen exceeds the mass of the ammonia used, and we're only talking about 250 PSI to liquify anhydrous ammonia at room temperature. A large pressure vessel's mass is going to be negligible compared to the mass of the ammonia it holds. So, the same displacement ship traveling at the same speed can supply the production of more steel if you ship the ammonia to the iron ore instead of the other way around.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#26

Post by icegreentea2 »

philipkglass wrote: post #6
PaulHoule wrote: post #4

Earlier quoted context omitted.

i think the question is how far you are shipping the hydrogen. If, say, people are making hydrogen in (say) the Middle East and shipping it to (say) Europe then the overhead of liquifying or compressing H2 is on the same order as converting to ammonia. In that paper they demonstrate that you can just use the ammonia directly to reduce iron and not have a separate system to convert it back. If you have a big wind powe…

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

From this (https://www.sciencedirect.com/science/article/pii/S095965261...), they estimate a scaled up process requiring ~50kg of hydrogen to generate 1000kg of steel (which would be about 1500kg of iron ore).

50kg of hydrogen should be equivalent to like ~600kg of ammonia (if I did my math right). So there's a substantial mass difference in one way shipping of 600kg of ammonia versus two way shipping of ~1000kg of solids to consider. In addition, since the tanker is empty on the return trip, if we were willing to play the travel time game, we could reduce tanker return speeds to try to compensate for running faster while carrying.

So I don't think it's completely cut and dry that shipping the iron ore/steel makes more sense.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#27

Post by shagie »

conradev wrote: post #9
philipkglass wrote: post #6

Earlier quoted context omitted.

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

This is how Iceland exports the bulk of its hydroelectric energy, but they use aluminum

I was going to correct you with geothermal, but then I looked it up and it turns out that the majority of Iceland's electrical production is indeed hydro rather than geothermal (TIL).

In finding the source for this, https://en.wikipedia.org/wiki/Energy_in_Iceland aluminum was the thing of note there. I was aware that this was the main power consumption (tangent to reading Artemis by Andy Weir).

> ... This trend continued and increases in the production of hydroelectric power are directly related to industrial development. In 2005, Landsvirkjun produced 7,143 GWh of electricity total of which 6,676 GWh or 93% was produced via hydroelectric power plants. 5,193 GWh or 72% was used for power-intensive industries like aluminum smelting.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#29

Post by shagie »

eutectic wrote: post #14

What about electrolysis?

The question is "what is the most efficient way of getting hydrogen at the source?"

Shipping it directly has problems with hydrogen being such a small gas and it is damaging to the vessel that it is transported in ( https://en.wikipedia.org/wiki/Hydrogen_embrittlement ).

Pushing electricity to the source needs a lot of power to work on the scale of steel production. Generating electricity from further away means power loss. Pumping water from the ground for hydrogen gives you ground water depletion (a serious issue in many parts of the world).

Ammonia is already a well understood compound for shipping. It doesn't pose the losses of shipping hydrogen and is already something needed in various places (fertilizer production).

Note that part of this is indeed doing electrolysis - at the location the ammonia is made rather than at the steel foundry. ( https://en.wikipedia.org/wiki/Ammonia_production#Haber-Bosch... )

In https://onlinelibrary.wiley.com/cms/asset/2299bce2-54a9-43ce... you will note that the cost of hydrogen production is the same - but the other costs of conversion and import / export terminals is much more.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#30

Post by benkitzelman »

Lots of refs here to the Haber-Bosch process in creating the ammonia... for those interested in a break down of what it is - https://www.carbonbrief.org/qa-what-does-the-worlds-reliance...

...sort of feels like kicking the can down the road if this is how the ammonia is generated for "Green Steel".

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