Katherine Gorman (00:04):
You are listening to Climate Now. I’m Katherine Gorman.
James Lawler (00:06):
And I’m James Lawler.
Katherine Gorman (00:08):
And today, we are investigating the world of biofuels.
James Lawler (00:11):
Where they come from, what percentage of our energy supply they represent today, and how that might change in the future.
Katherine Gorman (00:16):
And with us to walk us through all of those questions is Dr. Matthew Langholtz. He’s a natural resource economist in the Bioenergy Group at Oak Ridge National Laboratory. So Matt, thank you so much for taking the time to talk with us today.
Matt Langholtz (00:30):
Thanks for the opportunity.
Katherine Gorman (00:30):
So Matt, we ask all of our guests the same question first. How did you get where you are today?
Matt Langholtz (00:36):
I got my undergrad degree in forestry. Just kind of grew up interested in the environment, everything, you know, holistically speaking. Peace Corps after college, Paraguay, agroforestry sustainable development, soil conservation, forest conservation kind of stuff. Grad school, more forestry, sustainable forestry, forest economics, agroforestry, short rotation wheat crops, that kind of stuff. And I’m just interested in the potential for sustainable natural resource use.
Katherine Gorman (01:14):
Very cool. So let’s start with the basics. You’ve been the lead scientific author on several important studies on the economic availability of biofuels, and we’re excited to explore with you what biofuels are and how effective and reliable they’ll be in the future. But first, let’s get to the very fundamentals. Can you walk us through what biofuels are or rather biomass? Let’s be even more basic. What is biomass?
Matt Langholtz (01:41):
So generally speaking biomass is anything that is or was alive, any organic material, and that might have kind of slightly different connotations in different contexts or different sciences. But in this context, it’s pretty much plant material or even some waste, or some other kinds of organic materials that could be used to make energy.
James Lawler (02:07):
So, for example, you know, to put all of this, you know, the conversation of biofuels into perspective, give us a sense of, you know, scale, how much energy do we get today from coal, oil, natural gas, nuclear, energy, and renewables, and then, you know, within that renewables bucket biofuels.
Matt Langholtz (02:26):
Yep. So the US uses about 100 quadrillion BTUs per year, British Thermal Units per year. So conveniently it’s about 100 quads per year.
James Lawler (02:38):
And that’s our total energy supply?
Matt Langholtz (02:40):
Total energy consumed. On the supply side interestingly in 2019, we produced slightly more than we consumed for the first time in about 50 years. So we became, so in 2019 we produced 101 quads approximately and used about a hundred quads. Last year there was a little dip (2020), things went down to like 96 quads with the economic contraction, but we could call it over the past two decades or so about a hundred quads per year used and now approximately consumed and produced now.
James Lawler (03:27):
Got it.
Matt Langholtz (03:27):
And I could go into the fossil, the breakdown a little bit if you want.
James Lawler (03:31):
Yeah.
Matt Langholtz (03:31):
So of that 100 quads produced and consumed in the US, about 80 are from fossil energy. So those 80 quads from fossil, about half of that is from natural gas, followed by oil and coal. And then a little more than 10 quads are from renewable energy and a little less than 10 quads are from nuclear. So it’s about 80% fossil, 10% renewable, 10% nuclear.
James Lawler (04:08):
So, I think that’s interesting, you know, we hear all this talk about renewables, but so far they only represent about 10% of the energy supply that we’re currently using. And of that 10% then, what percentage is biofuel?
Matt Langholtz (04:20):
40%.
James Lawler (04:21):
40%. Got it. And in addition to that, of course, you’ve got all the others. So wind, hydro, solar. So is it right then that biofuel constitutes the largest piece of the renewables pie of that 10%?
Matt Langholtz (04:37):
That’s right. Yep. So of those 10 quads about four or five from biomass, about three each from wind and hydro electric and about one quad from solar, and this is all from US Energy Information Agency’s Annual Energy Review.
Katherine Gorman (05:01):
And so when we talk about the economic availability of biomass, can you explain what that means?
Matt Langholtz (05:07):
Yeah. So that ‘economic availability’ is a term that we picked up to help specify what we mean by potential supply. You know, when we think about biomass supply in the US, there’s some huge supply out there, but some subset of that is available within, certain environmentally sustainable criteria, and some subset – maybe overlapping subset of that – is also technically available, within our current logistical and operational potential. And some subset of that is what I call the economic availability. Basically how much could a market afford. You know, if you’re trying to produce ethanol, at say $2 or $3 or $4 a gallon, there’s a limit to how much you can pay for your biomass feedstock. So there’s a lot of biomass out there, but only some of it is sustainable. Some of it’s available. Some of it is cheap enough, and only a subset of that would probably be commercialized, would be commercially successful.
James Lawler (06:27):
And so Matt, how do we then go from biomass, which is what we’ve been talking about so far, to biofuels. You know, all of this biomass coming in from very different sources, as you’ve alluded to, how do we then get to something we can actually put into an engine.
Matt Langholtz (06:42):
The conversion side isn’t my specialty, but generally so we have biofuels today. There’s corn ethanol and through a process of fermentation, kind of like making beer, it’s used to make ethanol. On the cellulosic biomass side like we’re talking about here, there’s thermal chemical conversion. So, a combination of heat and chemistry to take biomass and convert it into liquid fuels and other products. Ere’s biochemical conversion, again, kind of like the ethanol, fermentation process.
Katherine Gorman (07:27):
You mentioned earlier that four or five quads of our current renewable energy supply comes from biofuels. What type of biomass is used to produce those biofuels?
Matt Langholtz (07:37):
Pretty sure it’s about 50/50 between biopower, which is largely industrial wood waste from the forest industry to make electricity. They use some of it, they use some of the electricity in their processes and put some back into the grid. And then another big part of that, I could verify at the end, anyone check me, but I think it’s about two quads that come from the corn ethanol – corn to ethanol – to be blended with gasoline at the pump. And then there’s some other little things in there, but that’s the bulk of it.
James Lawler (08:07):
In 2016, you led a study in partnership with the US Department of Energy called the Billion Ton Report. And in this report, you and the other authors went into great depth on the sources of biomass and their economic availability across forests, wastes, agriculture resources, and surprisingly algae. So, do you think you could discuss you know, what that economic availability looks like using current technology and infrastructure, and any other non-economic cost considerations to keep in mind as well when we think about these feedstocks?
Matt Langholtz (08:42):
So about a third of the US is in forest land, and about half of that forest land is considered by the US Forest Service to be productive enough to be considered timberland. So, potentially productive enough to produce forest products. Forestry is a big topic, you know, there’s a continuum of forest land goals, management goals, and priorities ranging from, you know, forest plantations, where we try to kind of optimize for wood production for pulp and paper dimension lumber, houses, decks, etc, all the way to preservation on the other side, where we don’t harvest anything to maintain ecosystem services. And there’s everything in between and multiple use.
Katherine Gorman (09:45):
Now you also worked with the University of Tennessee and the US Forest Service to evaluate the potential availability of biomass resources in the US. Can you tell us what you found?
Matt Langholtz (09:57):
So after we exclude protected lands, protected forests or sensitive forests and inaccessible forests, and using a model that accounts for the different forests have different ages. And some potentially could be harvested. Some potentially could be partially harvested or thinned. Some are too young. So depending on your timber stand age class distribution, this kind of influences how much could be available, how much wood could be available and how much biomass could be available at any year, but basically accounting for the land base, accounting for sustainability constraints, accounting for conventional demands for your conventional forest products. We find that at $60 a ton roadside, there’s about 100 million tons per year of wood that could be derived from forest thinnings and logging residues. So those are forest thinnings, trees that are less than a five or six inches diameter, and logging residues, tops and limbs that are left in the forest after trees are cut down. By the way, that’s less than 1% of the 15 to 20 billion tons of wood that’s standing on timberland. So it’s a tiny fraction of the total. It’s a significant potential cumulatively.
James Lawler (11:30):
And when we talk about roadside availability? What does that mean exactly? Where’s this 1% coming from?
Matt Langholtz (11:36):
We’re pretty much talking about existing managed forests that can also produce biomass, that do produce biomass now that largely goes unused and you know, from a forest perspective, we’re talking about if there’s a market support to remove biomass, then forest managers can remove small trees to let the other trees grow bigger, avoid forest fires, which as we’ve seen, have major costs in terms of homes and lives lost improve forest health. You know, active forest management includes harvesting and removals and fuel load reduction and things like this to improve forest health.
James Lawler (12:32):
Got it. And so basically we’re talking about forests that already have a Timberland designation by the US Forest Service. Is that right?
Matt Langholtz (12:40):
So there’s, you know there are a lot of forest lands basically in drier areas that don’t grow fast enough where you wouldn’t want, you wouldn’t want to cut down cause they wouldn’t grow back fast enough. I think it’s 20 cubic feet per acre per year or something, some minimum production. Yeah.
James Lawler (12:54):
And so what’s required to extract that value that you and your colleagues identified, you know, is this an opportunity for private companies to set up shop, collect this unused wood and cart it over to a processing facility or is it is more required to actually see the benefit or actually, you know, realize this value.
Matt Langholtz (13:11):
So I guess first and foremost, you need the market to support it. Then you need the infrastructure built to use it, just like anything else, you know, just like any other the current forest industry where we have pulp and paper, chip and saw, saw timber a market for these products and an industry that responds to it. If you have more price signals to use more of it then you could. I guess, you know, one extreme example maybe is maybe not, I don’t mean to say extreme, but you know, an example of market demand, in the UK, they have demand for CO2 reduction. They offer a price premium for wood pellets over coal. They have the Drax power facility in the UK where we export about 5 million tons per year of forest thinnings and wood waste, pelletized on barges, go to the UK and they produce power in the UK with wood from here.
James Lawler (14:16):
So you’re saying it’s worth it for a power producer in the UK to ship wood pellets on a barge across the Atlantic and burn them in a plant as opposed to just using oil or some other local resource because of the price on carbon that they have there.
Matt Langholtz (14:31):
Exactly, exactly.
James Lawler (14:34):
So that’s interesting because those boats that are taking those wood pellets across the ocean are not powered by clean energy, are they?
Matt Langholtz (14:40):
Nope. And I’ll give you a study where they do their lifecycle assessment and because barge shipment is so energy efficient, it comes out ahead.
James Lawler (14:52):
So you can ship a bunch of wood across the Atlantic and burn it for fuel, and it’s still more carbon efficient than coal.
Matt Langholtz (14:57):
It’s hotly debated. Right. And we could get there you know, we could go there it’s
James Lawler (15:03):
We don’t have to go down that road, but it’s sort of an interesting comparison, I think.
Matt Langholtz (15:06):
There’s research that indicates that it’s net carbon beneficial when compared with coal and, at the right carbon price signal, it’s economically viable to.
James Lawler (15:19):
Okay. So to summarize, I suppose, there’s this huge potential in the US to derive substantial amounts of energy from forest byproducts. Your team has identified how much that would be and what the price point could be as long as there’s a market for it say if we had some kind of carbon pricing scenario, but currently there is no market for it. Is that right?
Matt Langholtz (15:38):
That’s right. So biopower, so about, about half of that four or five quads is the biopower, that’s mostly wood. So that super, super low hanging portion, that super low -hanging fruit with the cheapest stuff is economically viable in the current market. And if you have more market signal, you could bring on basically more material.
James Lawler (16:00):
Interesting. So in the Billion Ton Report, you also named waste as another category of biomass. What is defined as waste here and how available is it to use as a feedstock?
Matt Langholtz (16:11):
Yeah, so waste is in the Billion Ton Report, waste is the most diverse category. There’s a lot of different stuff in there. There’s urban wood waste, so that’s like powerline trimmings and storm debris from urban areas, municipal solid waste, which is basically your garbage or the organic fraction of your garbage, there’s secondary wastes, which is mill processing residues. So nut processing fruit processing scraps from any kind of agricultural process manures from confined animal feeding operations fats, oils, and greases. So like, industrial fat byproducts, or grease byproducts, or restaurant grease traps and things like this. So a lot of different types of wastes. You know, I think it’s viewed favorably because people like the idea of using something that doesn’t have another use. So it has, I think, good public perception. It can have a negative cost, like potentially people are paying to get rid of it.
Matt Langholtz (17:31):
Maybe you have to add costs to sort it. It might not be as simple to convert to a biofuel depending on what it is. So a lot of potential in there, probably some economic low-hanging fruit in there, a lot of it already used. All the fats, oils, and greases already goes a lot to bio-diesel production. So the market works already where it can, but I guess, again, if you added a price for a carbon neutral fuel from waste, then maybe some more of this could also be economically available. So in our Billion Ton Report, we had about a 100 million tons of forest land resources, that’s at $60 a ton roadside. On the wastes, if we also could afford about $60 a ton, we’d get another a hundred million tons from this big mix of waste resources.
Katherine Gorman (18:27):
Great. The next category we have is agricultural waste. So agricultural resources and materials, this is different from the waste you were just describing, right?
Matt Langholtz (18:38):
Yup, different. So we’ve looked at the forest land base. We’ve looked at waste, now there’s the agricultural base. So all of our ag land, we look at separately. So the resources from agricultural land, two big categories, one is agricultural residues. This is mostly corn stover. We also have wheat straw. I forget what else, something else in there, but these agricultural residues that are left on the field. And the other is biomass energy crops. So let’s look at those residues first. So, you know, there’s some places where you have to leave the residues for soil conservation to avoid water erosion. There are other areas where there’s not enough that it’s economically viable to pick up. So about half of the supply maybe could be environmentally and operationally available maybe about 100 million tons of agricultural residues, most of that corn stover, available at $60 a ton, roadside.
Katherine Gorman (19:54):
So that’s yet another hundred million tons from another source of biomass that’s available. It’s fascinating because the picture that you’re painting, and correct me if this is wrong, but it sounds like with some adjustments on the policy side, in terms of pricing on carbon, it could very well transform what we do with all kinds of already occurring materials and resources in our economy that right now they’re just sitting there and we don’t currently recognize.
James Lawler (20:21):
Right, but if we did recognize it, I imagine this could create a sort of explosion of new businesses and jobs, because we’re going to need people to go out and collect all this stuff to process it, etc.
Katherine Gorman (20:32):
It’s really, truly incredible that if we just tweak the price of carbon, biomass can become a considerably large source of sustainable and renewable energy.
Matt Langholtz (20:41):
You got it. Yeah. So the current bio-economy, or at least when we looked in 2016, used right around 365 million tons a year. If you added 100 million from forest, 100 million from waste, 100 million from Ag, you would almost double the current bioenergy sector already, just with those things that exist today. Those forest land resources that are, I would argue under-utilized today, waste resources that could be used today, agricultural resources, agricultural residues that could be used today. And I haven’t gone into the biomass energy crops yet. So if you so the biomass energy crops, so purpose-grown biomass resources, that’s kind of like, the last terrestrial category. So again, we worked with the University of Tennessee to model this potential supply. And this is another economic model that accounts for the land base, accounts for the current allocation to different crops.
Katherine Gorman (21:50):
So when you say counts for the land base, what does that mean?
Matt Langholtz (21:54):
USDA reports, crop land and pasture land by county and the allocation of say corn, soycotton, wheat, etc. To each of those already. So there’s already an agricultural land base of uses.
Katherine Gorman (22:12):
Okay. So it accounts for the reality of where these crops are already being produced. It’s not hypothetical.
Matt Langholtz (22:19):
Yep. And it accounts for the – so, the USDA projects demand for food, feed, fiber, corn ethanol, export. So accounting for all that, accounting for the land base, accounting for projected demands, which kind of vary. The outlook varies year to year based on incomes in other countries that can affect diets in other countries, that can affect exports for animal feed in other countries that affects our demand. And then you get a tariff in there, that’ll throw things off this sort of thing, but overall doing our best to account for the current land base, the current resource base projected demand. And in addition to that, the demand for the conventional food, feed, fiber, fuel and exports can produce a little bit more biomass. We would target those biomass energy crops in ways that compliment the agricultural landscape already. So some lands are better suited, say for biomass energy crops some corn acres that might be a little bit more prone to erosion or maybe higher slope, or maybe, you know, biomass energy crops could have some competitive economic and competitive environmental advantages because you don’t have to plant them every year. You plant them once every year for 10 years or something that, so they do a good job at protecting the soil, maintaining vegetative cover. Anyways, you could produce another 400 to 700 million tons per year of energy crops. So basically you could double our bio-economy with the forest, waste, and ag. You could more than double it again, if you want it to include biomass energy crops.
James Lawler (24:11):
Wow. So now moving to the last category, which is algae. I’m kind of fascinated by algae for some reason. It seems like this infinite resource, but how does algae fit in as part of the current set of biomass feedstocks?
Matt Langholtz (24:25):
So you could produce micro-algae, which is kind of a little freshwater algae that you could grow in ponds. That’s what we looked at in the Billion Ton Report. There’s also macroalgae, basically seaweed, which also has a really interesting, I think, potential upscalability on the coasts. Both of these potentially can you know, their removal can potentially benefit ecosystems by removing nutrient wastes. With the micro-algae, we looked at production scenarios where we co-locate with CO2 sources, because if you add CO2 to the water, then the algae gets a yield bump. So we looked at scenarios where we locate the algae production with corn ethanol plants or coal or natural gas generation electricity generation plants, where we capture the CO2 from those plants use it to fertilize the algae ponds, increase the algae yields. So that’s good. It’s a way of recycling CO2 that comes out of an industrial process.
Matt Langholtz (25:42):
A benefit of algae in these ponds is that you don’t need agricultural land to do it. So there’s no food versus fuel issue. A downside is that you have to construct this infrastructure to produce the algae, which can be really expensive. So for example, on the terrestrial side, all those resources were what might be available at $60 a ton, on the algae side, the lowest price we get is around $500 a ton. So an order of magnitude more expensive. Now, potentially algae has other benefits. It might be more easily convertible. It just kind of a simpler biomass product that’s more readily convertible to say a bio-diesel. So it might be a higher value product, but it’s a lot more expensive. You know, if we’re looking all of the above options and all of the above solution to our energy and CO2 problems, then everything needs to be considered and probably everything has a place where it could be the best choice.
Katherine Gorman (26:54):
Yeah, and I’d love to touch briefly on the more widespread context of these things. What are the economic, infrastructural, technological barriers to the widespread adoption of biofuels in the US, and really globally in general?
Matt Langholtz (27:09):
So, the first-generation biofuels, of course are here now. We have the starch-based ethanol it’s at the pump it’s about 10% corn ethanol blended. Biodiesel has made significant gains in recent years. Brazil powers a lot of their transportation with ethanol from sugarcane. Germany, and other countries power a lot of their vehicle fleet with biodiesel. In terms of what we’re talking about in this conversation, the second generation biofuels from cellulosic resources, the wood, the wastes, everything you can’t eat, agricultural residues and things like this, so we’ve been hitting on, I think some of these constraints. A main constraint being it’s hard to compete with two or $3 gasoline at the pump, but basically cellulosic ethanol is modeled to be, is probably looking at about $4 per gallon of gasoline equivalent.
Matt Langholtz (28:19):
So if gasoline went to $4 or $5 a gallon, then second generation ethanol would probably be in the running. If you accounted for the CO2 benefit of a renewable fuel, then you could have a price premium on top of that price for biofuels. So you could afford to buy more biomass and afford to mobilize more biomass. I think of infrastructure barriers as economic barriers. So biomass is hard to handle, it’s heterogeneous, it’s fiberous, it’s stringy. We’re talking about bales of stuff rather than like train cars of coal. That’s more energy dense and flowable and things like that. So it’s just challenging, compared to fossil it’s economically challenging to mobilize. But if we accounted for costs of greenhouse gas emissions, soil erosion, water quality, things like this, and find logistical ways to shave off the price, then second-generation biofuels could start to compete more.
Katherine Gorman (29:22):
So to what degree are biofuels net-negative in terms of their overall CO2 emissions?
Matt Langholtz (29:29):
The upshot is biofuels are not CO2 net-negative. So biofuels don’t remove CO2 from the air, but they do avoid adding new CO2 emissions from the air. So they’re not net-negative unless you add carbon capture and storage or CCS to the system, then it’s net-negative. So there’s a really great hub out from John Fields and others at Colorado State. So this study looked at cellulosic biofuels and the net greenhouse gas benefit under a few different scenarios. Let’s say we’re growing switchgrass as a cellulosic biomass feedstock for biofuels. Your carbon benefit kind of depends what the prior use of that land was. So, it’s different if you say, if you grow switchgrass on ag land versus pasture land versus forest land, it wouldn’t be viable from a CO2 perspective to cut down forestland and start growing switchgrass.
Matt Langholtz (30:41):
But under some scenarios, if you take land, put it into switchgrass every year and that switchgrass absorbs about 50 or 60 tons of CO2 per hectare in the biomass. And if we use that biomass to produce ethanol, all of that CO2 is readmitted to the atmosphere. So there’s no net change, so it’s not carbon negative, but in the process of growing that biomass, we produced about 900 gallons of ethanol, which is enough energy to displace about 500 gallons of gasoline, which would have emitted about 6 tons of CO2. So in that system, we didn’t remove CO2 from the atmosphere, but we avoided putting about six or 10 tons of CO2 into the atmosphere. So that’s the avoided fossil fuel emissions.
James Lawler (31:36):
Now you’re also part of a group that did a large study on bioenergy paired with carbon capture and sequestration also known as BECCS. Could you summarize for us the key findings there, in terms of the extent to which we can use these biofuels to create bioenergy and then use CCS technology to store even more carbon than what is admitted? How much would that cost, and how well does that concept scale?
Matt Langholtz (32:05):
So bioenergy can be biofuels or it can be biopower like we were talking about, and you can take biomass-produced biopower and use the CCS to capture CO2 out of the air and stick it back in the ground. The Intergovernmental Panel on Climate Change has a few different pathways to net-zero CO2. By 2050 – we were talking about our resource potential, you know, 300 million tons exists today. You can add 400 million tons of energy crops, that sort of thing – if we use that resource base, use it to produce bioenergy with carbon capture and storage, what would the cost of that be? So, there’s been previous work on just that, I’m estimating about up to about 700 million tons potentially of CO2 sequestered annually. And we took that spatial distribution, looked that the geological sequestration basins, it’s kind of regionally across the country, and then accounted for distance and site suitability for doing this.
Matt Langholtz (33:07):
And basically in the near term, you know, using the near-term resources, you could sequester about 200 million tons per year. If you have the energy crops, you can sequester up to 700 million tons per year. We probably won’t get to all that because there are other uses for this. Another way to put it in context is the IPCC pathway 2 says the world might need a billion tons of CO2 sequestered per year to achieve carbon neutral in one of their scenarios. Here, you could do most of that from the US alone. So it’s, it’s not everything, it’s not enough for the solution, but it could be a key part of the overall decarbonization solution.
Katherine Gorman (33:51):
Dr. Matt Langholtz of Oak Ridge National Laboratory. A fascinating conversation James. I just love thinking this stuff, you know, being able to dig into these topics.
James Lawler (34:03):
Yeah, it’s really, really quite eye-opening to just consider how far just a little innovation can go. You know, pairing what we already know how to do with biofuels and carbon capture, and that that pairing with BECCS could get us to 700 million tons of sequestered carbon per year in the US alone, if we had sufficient carbon pricing. So perhaps, you know, a brighter future is not as far off as we sometimes think.
Katherine Gorman (34:34):
Well, that is it for this episode of our Climate Now podcast. You can check out our other interviews, watch our videos, and sign up for our newsletter at climatenow.com. And if you want to get in touch with us, email us at contact@climatenow.com or tweet us at @weareclimatenow. I hope you’ll join us for our next conversation.
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