#carbon_fiber, #carbon_fiber_2023, #composites, #sustainability, #fibers, #resins, #bio-based, #plant-based, #bio_based_acrylonitrile
First, I want to thank the Composites World leadership and staff for putting on an awesome event. There was an abundance of information presented, and some very enlightening talks about the state of the industry and where things are going in it.
Yes, that’s me up on the stage. This was my sustainability presentation where I advocated use of plant-based acrylonitrile as the precursor for PAN to make carbon fiber. I got some push back from the carbon fiber industry that I really had not anticipated. As it turns out, the carbon fiber industry has entrenched producers that are somewhat reticent to change even though the industry needs to begin working on reducing their carbon footprint. Carbon fiber has a very large carbon footprint, and if the industry tries to grow to meet the demand, fairly soon they will become regulated because of their carbon footprint. After all I’ve been looking in to this stuff and writing about it for a while now, so the pushback was probably to be expected. At least the word is out in public now, and the producers are on notice. More about that later on.
One of the key things I took away from this conference was provided in a presentation by Dan Pichler, Managing Director of CarbonConsult GmBH. Dan presented the opportunity for carbon fiber that the burgeoning wind turbine market is making possible. We had heard earlier in the day from Steve Nolet of TPI Composites about the requirement for wind turbine blades to be made from mostly carbon fiber. This is because of the economies of scale – meaning that the larger the wind turbine, the more electricity it generates, and the less that energy costs when you put it on the grid. In fact, the large wind turbines of today cost less per kilowatt produced in real dollars than the smaller machines of the past. And, because the blades are much longer, what is called the “spar caps” which are the front and back surfaces of the blade, must be made of carbon fiber just to handle the tension and bending loads of a spinning rotor. Plus the carbon fiber in the spar caps also reduces and/or removes the risk of a “tower strike”.
This needs a bit of explanation so that everyone understands what could cause a blade to hit a tower. All major large wind turbines of today use upwind rotors, meaning that the rotating turbine blades are in front of the tower rather than downwind of the tower. If the rotor is downwind of the tower, every time a blade passes behind the tower, the force on the blade goes to zero, causing the blade to go through one fatigue cycle, because the wind picks back up again as soon as the blade passes out of the shadow of the tower. This fatigue cycle seriously shortens the life of the wind turbine blades. Most of the fatigue damage is done at the blade root, because the connection of the blade to the hub of the rotor is made out of metal. Composites have very long fatigue lives, but the metal part at the hub doesn’t. So, to make sure that the wind turbine blades last for 25 or so years with millions of cycles, wind turbine rotors of today are all upwind.
So, as the wind blows against the upwind side of the blade, the blade bends backward toward the tower. The longer you make the blades, the more this force bends the blade. And the last thing that any wind turbine operator wants is for a blade to hit the tower because the wind is blowing too hard. Wind turbine designers must avoid tower strike at all costs because if a turbine blade hits the tower in a gale force wind, the entire wind turbine will disintegrate, and probably throw parts of itself all over the place, possibly damaging several other wind turbines in the process. That would be a bad day for the wind turbine operator.
Why carbon fiber? Glass fiber is not only heavier than carbon fiber, it is also not nearly as stiff as carbon fiber. So, as we make wind turbines larger and larger to lower the overall electricity cost, there is a blade length beyond which glass fiber just doesn’t cut it. So, all large wind turbines, which are being made at an ever hastening clip, use unidirectional carbon fiber for their spar caps.
Because we need carbon fiber for all of the new wind turbines being made, and because of the Inflation Reduction Act and the Infrastructure Act here in the US, if you look out 20 to 30 years, according to Dan Pichler the need for carbon fiber just for the burgeoning wind market will be 10 times current manufacturing capacity.
Then there is the carbon fiber need for the upcoming hydrogen economy, primarily for our transportation system. That was also brought up a bit after my talk about sustainability by Tim Kirk of Toray. The need for Composite Overwrapped Pressure Vessels (COPVs) to store hydrogen at something like 15,000 psi, which is also enabled by carbon fiber, is another 10 times current worldwide manufacturing capacity for carbon fiber.
The upshot of this is two-fold. First, whereas carbon fiber is currently more a niche market where fibers are sold based on the weight savings and mechanical properties that can be achieved using the fiber, very soon carbon fiber will be enough of a commodity market that there will be a “standard” carbon fiber and the producers of carbon fiber will not compete based on properties, they will compete based solely on cost.
The second upshot of this is something that Dan Pichler said. The current producers of carbon fiber can only expand production so fast, so there will be new entrants in this market who will not necessarily produce carbon fiber the way it is being produced today but will use new technologies that are proving to save not only on precursor cost but also on the energy cost to produce carbon fiber.
To that end, there are at least two new developments that are beginning to scale up. One of them I have talked about in this space quite a bit, and that I talked about at the conference. That is the scale up of plant-based acrylonitrile made from forest product and agricultural waste. Solvay has already entered in to an agreement to scale up the process that was developed by Southern Research. And both Toray and Teijin are also working on this as well. All of these companies understand that at some point they need to move away from petroleum based precursors to plant-based, if only for political reasons. With carbon fiber’s large carbon footprint people are taking notice of this. If some of the big players in this market don’t move rather quickly to lower their carbon footprint they are going to suffer the consequences.
That was actually the point that I was making in my talk a bit earlier in the day before some of the larger players in this space got up to speak. So, even though I got some public pushback from some in the industry, my position was validated by speakers later in the day. Like I said, this was an awesome conference. It was also nice to get positive feedback from others later in the day. That means that the message I was trying to send to the industry got delivered.
Before I go there is one more piece to the carbon footprint puzzle for carbon fiber that a gentleman from a Japanese company – Microwave Chemical Co., Ltd. – where these folks have developed an industrial size microwave processing technology for conversion of PAN fiber into carbon fiber without the use of gas-fired ovens. Since their technology uses only electricity, that electricity can be generated using renewable resources. And, since microwaves heat the fiber from the inside rather than baking in an oven where the hear gets applied to the outside, their technology uses a small fraction of the energy of current processes, and has a much faster throughput. In other words, the processing cost using their technology to convert PAN fiber to carbon fiber is a fraction of the cost of the current petroleum fired ovens.
Needless to say, not only am I optimistic about the potential of these new technologies, I am actually excited to be part of what is going to become a multi-billion to trillion dollar industry that has a near zero carbon footprint.
That’s about all I had for this week, and I will be writing about this subject and about what I learned at the conference for the next few weeks. And I will also be doing what I can to spread the message throughout the industry. Fortunately Composites World has a new microsite in sustainability, so I might write a few things for them and see if they like them enough to put what I write in their publication. We’ll see how that works out, but that would be wonderful.
Finally, and as usual, I need to sign off with the fact that my book is out and ready for anyone to purchase. The best place to get one is to go to my website and buy one. I will send you a signed copy for the same price you would get charged on Amazon, except that I charge $8 shipping. Anyway, here’s the link to get your signed copy: https://www.nedpatton.com/product-page/the-string-and-glue-of-our-world-signed-copy. And again, here’s a picture of the book, for those of you just tuning in.
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