The Petcoke Podcast: The shift towards low carbon aluminium (Part 1)

Author Argus

In this episode of the Petcoke Podcast, Argus editor Lauren Masterson speaks to Les Edwards, Vice President of Production Control and Technical Services for Rain Carbon, about the shift towards lower carbon aluminium and its effects on petcoke markets.

Hear about the initiatives that Rain, as a carbon and chemicals producer, is working on to transition towards a lower carbon footprint and the outlook for carbon product demand as the world seeks to counter climate change.


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Listen to Part 2 of this episode here


Lauren: Hello, and welcome to the "Petcoke Podcast." In this series, we'll be speaking with key industry participants to gain their insight into the latest trends for petroleum coke markets around the world. I'm Lauren Masterson, editor of the weekly Energy Argus Petroleum Coke publication. In today's episode, we'll be discussing the shift to lower carbon aluminum markets with my guest, Les Edwards, Vice President of Production Control and Technical Services for Calciner Rain Carbon. The "Petcoke Podcast" is brought to you by Argus Media, a leading independent provider of energy and commodity pricing information. Thank you for joining me today, Les.

One thing about the Covid-19 pandemic that strikes me is that it seems to have accelerated some long-term trends that have been around for a while but really seem to have picked up speed over the past year. The transition from fossil fuel energy to lower carbon alternatives seems to be one of those trends in my mind. So in Rain's latest earnings call, CEO Jerry Sweeney mentioned that developing environmentally friendly products for the 21st century will be one of your main goals over the next few years. As a company that buys and sells carbon-based products, I'm curious, what are some of the initiatives you're working on to transition the company into a lower carbon future?

Les: Well, thanks, Lauren. Thanks for the introduction and thanks for allowing me to participate in this podcast. Yeah, so I guess Rain Carbon, as our name suggests, we are a carbon and chemical products producer. So, we are not planning to transition away from producing carbon anytime soon. But we have had a pretty intensive effort, I would say, in the last 18 months focused on what we can do to improve our sustainability performance. And so, just to walk you through a couple of the initiatives and projects that we're working on in that area, so, the first one, which we've presented a paper on this at last year's TMS meeting on our ACP technology, anhydrous carbon pellets. So, we are currently building a commercial plant at our Chalmette Calciner in Louisiana.

So this is a technology where essentially we will reduce the tons of green coke required to produce each ton of calcined petcoke. So, that'll help us reduce our CO2 emissions, our SO2 emissions, as well as producing a product which, you know, has a higher bulk density and will help our, you know, aluminum smelting customers. So, I think that's a very good development for us in terms of reducing at least our carbon footprint. And then, you know, we've just finished constructing a shaft calciner in India. That is a technology also that uses less GPC per tonne of CPC. So it has a good carbon footprint story.

And that calciner also, you know, we employ SO2 scrubbing at most of our, you know, anode grade coke calciners. And that new shaft calciner will have our most sophisticated SO2 scrubbers, so an ammonia scrubber, which is able to remove up to 99% plus of the SO2. Our current calciner in there is already very efficient at 98%. This is even more efficient and will produce a byproduct then it'll be used in the fertilizer industry in India. 

Another example of something we've done in the last 10 years to, again from a sustainability perspective, again, in India, we used to burn quite a lot of low sulfur heavy stock fuel oil in our calcining kilns. So we needed to supplement the heat for calcination by burning that fuel oil. We've now completely eliminated that during our routine production by building an oxygen plant. So the oxygen plant, we use power from our waste heat energy recovery system, which generates electricity. And we use that to power the oxygen plant, which makes oxygen which we inject in the kiln. And that eliminates, you know, the need for the fuel oil. So that's some of the things we're doing in the calcining business unit. If you look elsewhere in our global organization, we have a pretty major effort underway in Europe too, which is focused on improving our energy efficiency. And I think Europe is quite a way ahead of the U.S. in terms of some of the initiatives in the European Union to drive organizations to be more energy efficient. And some of the learnings from Europe we’re transferring to our U.S. and India organization. 

We recently commissioned a new hydrogenated hydrocarbon resins plant in Germany, which will produce a much higher value-added hydrocarbon resin. So that'll be used in the food industry and healthcare product industry. Something for us for the future — we already supply some coating binder pitches into the lithium-ion battery market and we see that as a very big growth area for us. And so, just coming back to your question about, you know, the low carbon aluminum future, obviously, there is a lot of focus now in the aluminum industry to reduce its carbon footprint given, you know, the amount of CO2 emissions that the industry generates around the world. So we definitely want to be part of that drive to reduce emissions. So we've been very active in that industry. So, we've presented a paper last year, for example, on what our CO2 footprint is, we now have a modeling group set up in Germany that does the CO2 footprint modeling, and so we're able to use that to, you know, identify just where our carbon footprint is right through the aluminum supply chain.

And then, you know, recently we played a pretty key role in organizing a keynote session at the TMS meeting on, you know, sustainability in the aluminum supply chain. So there is a lot of work around the world on all parts of the supply chain. So, you know, in the aluminum production, obviously, the smelting and then we’re trying to do our piece in the carbon supply chain. So that's sort of an overview of some of the things we're doing now.

Lauren: So, as you mentioned, the ACP are still originally derived from green petcoke from crude oil processing. We've seen over this past year how a decline in transport fuel use directly translates to very tight green anode coke availability. While this is in some ways temporary, do we see some refineries transitioning to hydrocracking or biodiesel or just shutting down, you know, in a new kind of market? So, is this transition...? I mean, we're seeing maybe electric cars, you know, differences in air travel. Is this something that you are looking into in terms of alternatives to petroleum-based carbon anodes?

Les: Well we have done some work in the past on biocarbon alternatives. So, there is, I would say an active body of research going on around the world that's been going on now for more than 10 years to see whether there are biocarbon alternatives to both calcined petcoke and coal-tar pitch. So, we've tested some biocokes. We've also tested a biopitch. And I'd say our experience is not too much different to others, in that with the biocokes, the big challenges tend to be... And when I talk about a biocoke, so charcoal is probably the most widely tested, you know, biocoke that's out there. And the significant challenges with biocoke materials are reactivity. 

So you tend to have some... You have a structure, which is a fairly highly reactive structure. There's a lot of closed porosity in the structure. It tends to be high in salt trace metals, like, you know, potassium, magnesium, sodium, and silicon. So that elevates the reactivity, particularly with CO2, so you end up with very high anode consumption rates. And then the other significant challenge with biocokes in it's related to that closed porosity, the bulk density of those cokes tends to be very low. So, when you try and use it as a replacement for petcoke, you end up with a very low-density anode, very highly reactive anode. Yeah, so, Hydro Aluminum from Norway, they published a very good paper on some work they did on using charcoal in anodes back in 2010. This was work done on a pilot anode scale. So there's been a lot of other groups around the world have done, you know, similar work since then. And they've all run into the same kind of issues that I just described.

And then on the biopitches, the challenge there is, most of the biopitches are fairly high in oxygen content. So, when you look at the coking value of those pitches, they're much lower than a standard coal-tar pitch. So, that also has a pretty significant, you know, performance impact in the anode plant. And also, you know, in combination with a biocoke, it's even more challenging to make the economic case. And then the other issue with these biocarbon alternatives is just the supply availability. So, there was a recent study done in Norway, where there just simply isn't the forest capacity, you know, to be able to supply enough of those materials to make a significant impact in the industry. So, I think in terms of, are there any alternatives out there for, you know, calcined petcoke and coal-tar pitch? The answer today is really no. 

Lauren: So it sounds as though there's still pretty significant challenges to removing the petroleum side from carbon anodes. Are there any other alternatives being developed to replace a carbon anode entirely?

Les: Yeah, well, I guess the big one that most people would be aware of at some level are inert anodes. So, as the name suggests, inert anodes are non-consumable anodes. So, you know, with a carbon anode, of course, you continuously consume the anode and generate CO2. The idea for an inert anode is that it is something that, you know, has very low corrosion rate and will, you know, remain in the cell for an extended period of time. So this has been worked on actually all the way back to when the aluminum process was first discovered. So if you go and you read the Charles Hall Patents that were published in, sort of, 1886 to 1889 period, they mentioned inert anodes. So, you know, the industry has investigated, tried to develop inert anodes for a very, very long time.

And I think that's a testament to just the challenge that, you know, complexity of trying to develop that type of technology and produce a truly inert anode. So the attraction of course is if you can make a non-consumable anode and not generate CO2, that obviously in this environment when we're trying to reduce the CO2 footprint, that's a very attractive technology to pursue. So an inert anode basically generates pure oxygen, you know, at the anode. But as I say, the challenges there are quite significant. So if you go back to 2000, so Alcoa made a very big announcement in 2000 that they were very close to commercializing inert anode technology. So they basically said that within a two to three-year timeframe, they were going to retrofit inert anodes to all of their existing smelters, you know, around the world. And so, probably three or four years after that, they largely, you know, abandoned the effort because they ran into some fairly significant process challenges. And I think that's a little bit symptomatic of the way sort of inert anode technology has evolved and been developed. There are just a lot of challenges to get that technology to work. So it's been done on a small scale. And so, you know, we now have a major effort underway in Canada with the Elysis joint venture.

So that's a joint venture with Rio Tinto and Alcan with some very significant Canadian government funding and a little bit of funding from Apple. So they started that joint venture in 2018. And what they're doing is they’re basically marrying, you know, inert anode technology with what they call wettable cathode technology. And they are trying to develop a vertical cell configuration, so you have series of parallel vertical anodes and cathodes. And the idea there is if you do that, you can save some energy versus trying to retrofit an inert anode to an existing sort of horizontal cathode cell, which is what Alcoa were trying to do in 2000. So that work is underway.

They've finished building their R&D center which is in the Saguenay region in Quebec. And I think they are in the process now of building their first prototype cell, which is not a full-scale commercial cell. It's something smaller than that. No one's clear on exactly how long that will take, but that technology has, you know, quite a long way to go in its development. So people have been successful at operating inert anode cells at the bench scale. And then Rusal in Russia has done quite a bit of work where they've operated cells for a period of time at a larger scale. But the challenge is always to, you know, produce aluminum that's got low contamination, you know, concentrations at scale for an extended period of time. So getting the inert anode to be truly inert is one of the big challenges. And then another significant challenge is the energy consumption with an inert anode cell is around 30% higher than a carbon anode cell. And that's because the reversible potential with an inert anode cell is significantly higher. So, you know, for a process that the energy accounts for something like 35% to 40% of the cost, that's a very substantial burden.

So that's been a bit of a disincentive in the development in the past but I think the Elysis approach where they're marrying the two technologies is the right approach because it can help reduce some of the energy gap but it also makes the technical challenge even more sort of complex than just trying to do an inert anode, trying to retrofit inert anodes into an existing sort of horizontal cathode cell. So, that development's under way, but I think it has quite a long way to go. So Elysis has basically said that they would have a commercial cell ready by 2024. I think most industry experts would say that's extremely, you know, optimistic timeframe and we're sort of three years into the joint venture. So I think the Canadian government's said they were funding that project for a six-year period, so we're already halfway through, and they're just at the point of building their first sort of intermediate scale cell. So having something commercially available by 2024 seems, I would say, rather optimistic. So, yeah, so I think that's certainly the long-term direction for the industry. But people will probably say a 2035 timeframe and above is, I think, a more realistic sort of timeframe for that technology.

Thanks for that explanation. With that, I think we’ll stop here for today just in the interest of time. We’ll pick up this discussion next week in the next episode. Thanks Les for joining me. And thank you everyone for listening. And if you enjoyed this podcast, please be sure to tune in for the other episodes in our series “The Petcoke Podcast.” For more information on Argus Petroleum Coke coverage, please visit at

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