Host: Shayle Kann
Guest: Rebecca Dell | Program Director for Industry | Climateworks Foundation
Category: ☁️ Carbon Reduction
Podcast’s Essential Bites:
[6:53] “Fertilizer and plastic [are] between 75 and 80% of all the GHGs (greenhouse gasses) from the whole [chemical] sector. […] And the reason for that is pretty simple. It's because we produce plastics and fertilizers in increments of hundreds of millions of tonnes per year. Other products we produce in much smaller quantities, and so their total GHG and energy impact is way lower.”
[7:53] “Mostly what we're talking [regarding] fertilizer is reactive nitrogen. So nitrogen is most of our atmosphere, but the nitrogen in the atmosphere is chemically unavailable for use by plants, animals, and biological things. So we need to convert it into a form that it can be easily used by. Mostly, the way that we do that today is through […] the Haber–Bosch process. And so we start with fossil fuels, we use them to make something called sin gas, which is a combination of carbon monoxide and hydrogen, we combine that hydrogen using a catalyst with nitrogen from the atmosphere, and we make ammonia, which we use for fertilizer. And ammonia is […] the single chemical product that we make in the largest quantity. We make almost 200 million tons a year of ammonia globally. And it's responsible for 1.5 % of all greenhouse gas emissions.”
[13:50] “From a […] energy and emissions perspective, […] we talk not so much about the plastics themselves, […] we talk more about the precursor chemicals, which are where most of the energy and most of the greenhouse gas emissions come from. […] [The] shortlist of the most important of those precursor chemicals [are] are ethylene and propylene. […] And then methanol, which is a chemical that is extremely widely used in a ton of different types of products. […] There's a set of chemicals, which we call BTX, stands for benzene, toluene, and xylene, which are sometimes also called light aromatics. So […] that set of chemicals, ethylene, propylene, methanol, and BTX, are collectively mostly what we're talking about when we talk about plastic.”
[16:18] “This issue of upstream methane leakage is incredibly important and is often thought of as […] out of scope for conversations about decarbonizing the chemical industry. […] The best guess of current leakage rates in the US [is] 2.5% average. […] That can, over a 20 or 30 year lifetime, […] double the climate impact of your fossil fuel inputs. […] So if we don't talk about the upstream leakage, […] we might miss half the problem.”
[17:19] “One of the ways that the chemical industry is quite different, and particularly the plastics industry, […] than a lot of other industrial activities, is that you're not just using you these fuel inputs as fuel, […] most of it, in fact, we're not burning. We're only burning about 40% of it for energy, the other 60% of it were actually converting into the products themselves. So plastics are carbon based chemicals. Where do we get all those carbon atoms? We get them from fossil fuel inputs. And so this is why the chemical industry is the most energy intensive industrial sector. But it's only the third most greenhouse gas intensive industrial sector, because most of the energy is actually not going into the atmosphere, it's going into the physical product itself.”
[21:07] “Plastics don't emit a lot of greenhouse gasses, when you use them. They're mostly inert in their useful life. But they can emit a lot of greenhouse gasses at the end of their life, because we like to incinerate them. […] If you look at just the production phase of plastics around the world, we are talking about something in the neighborhood of 900 million tons of CO2 that's getting emitted. But if you look at the whole lifecycle estimates are more like 1.7 giga tons, so almost twice. […] Current trajectory estimates are that the 1.7 billion tons of CO2 that we're emitting today might quadruple by 2050, if something doesn't change.”
[26:26] “Basically all plastics today are made out of fossil fuels. And as we were talking about, less than half of the energy is used as energy, you burn that fossil fuel to get energy out. More than half of the energy is converting […] the atoms in the fossil fuel into the atoms in your product. So that's the energy side versus the feedstock side. And when we think about solutions, we have a set of solutions on the energy side. […] You can imagine a world in which we use clean energy to drive these processes, but are still getting the atoms that we need from fossil fuel. You can also imagine a world in which you are trying to get clean feedstocks. This is like […] that biodegradable plastic fork you might encounter. That is a situation where they're trying to use a clean feedstock in the form of biomass, but they are almost certainly still using dirty energy. Or you can try and do both.”
[30:52] “One of the most energy intensive things in the chemical industry is chemical separations. You have a reactor, you get a soup of a whole bunch of different chemicals out, and you want to separate the one from the other. The way we usually do that today is by heating up your soup in a tall skinny column. And then that will cause the small molecules to rise faster than the big molecules. And you can sort of siphon off at different levels to get different sizes of molecules. […] If we could use membranes, or non-thermal processes to separate out different chemicals, we could potentially cut the total energy demand of those separation processes by 80 to 90%.”
[34:09] “Today, […] the most energy intensive part of the whole chemicals industry system are these process units that are called crackers, […] a lot of them are steam crackers, where you put in a lightly processed fossil fuel, […] like ethane. […] And you get ethylene mostly […]. And so those process units are running at high temperatures in anaerobic environments to split the molecules into smaller molecules. And when I say high temperatures, we're usually talking like 700 to 1100 Celsius. […] And there are certainly technologies that we can use to convert electricity to temperatures that hot. But nobody's bothered to commercialize an electric cracker. Because right now, electricity is way more expensive. And so it wouldn't be cost effective even if it worked. […] So an electric cracker, that's the thing we could do. It's not a thing that exists right now.”
[37:09] “I see the clean energy side as […] significantly easier and likely to be significantly cheaper than the clean feedstocks side. […] The clean feedstocks are […] basically two big categories here. We can get our carbon from biomass or we can get our carbon from CO2. And so on the biomass side, that is perfectly feasible. But as with everything related to biomass, the problem that you run into right away is where are you going to get enough of it? […] Currently, the chemical industry uses something like 30 exajoules of fossil energy […] just for feedstocks. And the International Energy Agency estimates that the total amount of biomass available for use for energy everywhere on Earth is something like 55 exajoules. So if we wanted to replace all of it, we would need more than half of all of the biomass available on Earth, just for this one industry.”
[40:53] “To make one tonne of these high value chemicals, […] these plastic precursor chemicals, is going to require between 3 and 4 tonnes of dry biomass. It's only going to require 1.2 tonnes of petroleum product. And so you have two problems. One, you have to move a lot more stuff. And two, you have to move solid stuff instead of liquid stuff. […] So people are thinking about […] creative ways that we can get […] around these logistic problems.”
[44:59] “We are emitting CO2 into the atmosphere at the scale of tens of billions of tonnes per year. We are making plastics at the scale of hundreds of millions of tonnes per year. So there's two orders of magnitude in between those two. And so when we talk about carbon utilization here, don't think of it as this is a sink for CO2. Think of it as this is an opportunity for a truly circular carbon economy, that everything that goes out, gets sucked back in. And we can have these products, but without creating damage from the production of these products to the climate. […] The idea is you can take CO2 and H2O, and you can electrolyze both of them. You can use clean electricity to cut them in half and get your carbon and your hydrogen from those two inputs, and then synthesize those into all of the chemicals that we're talking about, ethylene, propylene and others.”
[49:18] “I am very bearish on the possibility of decarbonisation under current market conditions. I think that the future chemical industry is just going to have to sell its products at higher prices than they are currently. And from a full social cost, that's going to be cheaper for everybody, because they're no longer going to be dumping their climate pollution in the atmosphere. But […] there will be marginal cost associated with that. And every study that has looked into this comes to the same conclusion. The most optimistic studies say that clean production might be 30% more expensive than today's production. Some studies find it'll be two to five times more expensive.”
[53:21] “Over the whole history of the world, we've made about 6.5 billion tonnes of plastic. About 5 billion of those tons are still around. And they are either in landfills, or just dispersed in the environment. […] About 800 million tonnes, we think, has been incinerated, and then about 600 million tonnes, so maybe 7 or 8% of all the plastic that's been produced, has been recycled in some form. So mostly what we do with plastic is we just dump it.”
[55:32] “We mix the plastic in with organic waste and put that in the landfill. And because there's all this plastic mixed in with the organic waste, the organic waste doesn't have any access to oxygen. And so it decomposes anaerobically and emits all of its carbon as methane, instead of as CO2, which is what it would emit if it were composted properly. And for every atom of carbon that comes out as methane instead of CO2, it's between 30 and 80 times more climate damaging than if it had been composted properly.”
[56:53] “In theory, most of the plastics we use are infinitely recyclable. […] In practice, we are incredibly bad at retaining material value from one use to the next. […] This is because we tend to just mix all the plastics together and some of them are easy to recycle and others […] are hard to recycle. But in all cases, if you have a highly impure waste stream, […] things that used to be useful additives are now impurities that are compromising material properties. And so what you get out is a much lower quality plastic than what you put in. […] In the US, the EPA estimates that only 8 or 9% of plastic is collected for recycling at the end of its life. And then only about half of that actually gets recycled. And […] the products that we get out of the end at the end of that is a very, very low quality plastic. So right now, we are doing a terrible job. And this ties back to the question about clean energy versus clean feedstocks. Because […] even if we have high recycling rates, if eventually where that plastic ends up is in an incinerator, then the CO2 ends up in the atmosphere, even if we use clean energy to make it.”
Rating: ⚡⚡⚡⚡
🎙️ Full Episode: Apple | Spotify
🕰️ 1 hr 6 min | 🗓️ 01/24/2022
✅ Time saved: 1 hr 2 min
