Catalyst N° 041 of 125 2 Dec 2024
From biowaste to ‘biogold’
with Julio Friedmann, chief scientist, Carbon Direct
In this note
The question
There is only so much biomass, and every use of it competes with every other use. What should we actually do with it?
The answer
Friedmann refuses to name a single winner, and says so deliberately: the best use is a values question that reasonable people answer differently, and it will eventually be settled by governments rather than by analysis. What he offers instead is a rule and a sequencing. The rule is that biomass is poor energy and good carbon, so above a fairly low carbon price it is worth more buried than burned. The sequencing is that supply is not yet the binding constraint, so for the next decade or so the useful question is what we can do rather than what we should.
03The argument
The setup is a correction to the intuition most people bring. Biomass is not a natural net sink. Before humans it was roughly a wash, carbon in and carbon out, and the biosphere broadly still is; what moved carbon into the atmosphere was people taking it out of the biosphere by cutting forests and clearing land for agriculture. Only a small fraction of the carbon cycle passes through biomass at all, though the carbon held in biomass is much larger than the carbon in the atmosphere. That reframes the objective. The point is not that plants absorb carbon, which they already do and then release again. The point is to use biomass as a conveyor belt, moving carbon from the atmosphere to somewhere it stays.
Waste biomass is where the investors and governments have landed, and for two reasons that are worth separating. The first is negative: waste sidesteps the competition for land, ocean and nutrients, and therefore the competition with food. The second is positive: wastes are things already headed for the atmosphere, so using them starts from a better carbon position. There are three categories, forestry waste such as bark, twigs, slash and dead trees; agricultural waste such as corn stover, straw, almond pits and walnut husks; and municipal solid waste, meaning trash. Kann’s standing objection to anyone pitching waste biomass is that the stuff is too diffuse to source at gigaton scale, and Friedmann overturns it specifically for waste: general biomass is distributed, but waste has already been aggregated by somebody else’s logistics. California has a hundred million dead trees, which he later locates in the Sierra Nevada. The Central Valley concentrates agricultural residues wherever the food is processed. Landfill waste is pre-concentrated because trucks already hauled it there, which is why waste companies are now working out how to capitalize it. The dispersion problem is real for biomass in general and much weaker for waste in particular.
The catch is that “waste” is an unstable category, and Friedmann keeps returning to how this goes wrong rather than to how much is available. A facility converting biomass to jet fuel wants a twenty-year feedstock supply locked up, and so does everyone else eyeing the same landfill, which prompts his sharpest line: is it really a waste if people are fighting over it? The failure modes are specific. Eco-colonialism, meaning paying people in one country to clear a rainforest, grow a fuel crop and ship it to a wealthier economy, is the worst of them. Long supply chains burn fuel and money on their own account. Diverting a waste stream can release more carbon dioxide than it saves, and he flags when a waste stops being a waste as a genuinely vexing unsolved question. Europe is his named risk case: it buys a lot of sustainable aviation fuel, has very little land, and is not currently converting its own waste, so a policy aimed at something virtuous can produce deforestation somewhere else.
That leaves the allocation question, where the episode does produce a rule. The options run from burning biomass for electricity, which he calls a Russian tractor approach, effective and crude and yielding a low-value product into a market already crowded with alternatives; through gasification into syngas, which can drive a turbine, be upgraded to hydrogen with the carbon separated out first, or feed a Fischer-Tropsch unit making diesel, gasoline, jet fuel or chemicals; through pyrolysis, which yields fuels, gases and biochar; to simply burying the biomass and producing no energy at all. Against that menu sits what Friedmann’s colleague Roger Aines named the Aines principle: biomass is pretty crappy energy but pretty good carbon. At almost any reasonable carbon price, removing the carbon beats converting it into energy, with the crossover as low as around $60 a ton for some systems and covering essentially everything at $100 to $120. It weakens as the energy product gets more valuable, biting hardest against power generation and least against jet fuel and hydrogen, but the crossover exists in every case. What Friedmann then declines to do is let that rule decide policy. We have not come close to the limits of supply or of the investment needed to reach them, so treating this as zero-sum now is premature; carbon removal and sustainable fuels are both unsolved problems worth attacking at once. The same logic answers Kann’s worry that bio-based aviation fuel is a rabbit hole that cannot rinse and repeat at scale: there are 42,000 airports with fuel depots and trash near all of them, jet fuel is already produced in a few places and shipped everywhere, and moving fuel is far cheaper than moving biomass, which is mostly water and a mess. He grants that limits arrive as things scale and that food-fuel competition has to be worked against, but not yet. The constraint he expects to bind is institutional rather than physical: sooner or later a government will publish a loading order naming the first and second permitted uses of biomass, and because the market will by then be full of long-term contracts, that will shake things up badly.
04What you need to know first
- Gasification and syngas
- Heating biomass in a gasifier produces syngas, a mixture of hydrogen and carbon monoxide. Syngas is the fork in the road: it can go to a turbine for electricity, be upgraded to pure hydrogen, or be fed to a Fischer-Tropsch unit that assembles it into liquid fuels and chemicals.
- Pyrolysis and biochar
- Roasting biomass without burning it, the same operation as roasting coffee, sometimes called torrefaction. It yields gases, liquids and biochar, a solid carbon product used either as fuel or as a soil amendment that Friedmann says can improve crop yields and store carbon “under the right circumstances,” a qualifier he applies to both.
- BiCRS and BECCS
- BiCRS, biomass carbon removal and storage, is using biomass purely to move carbon into durable storage with no energy produced. BECCS, bioenergy with carbon capture and storage, makes energy and captures the carbon, and is a subset of BiCRS. The machine transcript renders these phonetically as “bikers” and “Beck’s.”
- The Aines principle
- Named for Friedmann’s colleague Roger Aines: biomass is poor energy and good carbon, so at most realistic carbon prices its carbon is worth more than its energy. It is the one crisp decision rule the episode produces.
05Details worth keeping
- Denmark is his model of doing it right: a municipal waste incinerator generating electricity with a ski slope built on top of it, in a country notoriously short of hills.
- Lancaster, California is his example of a complete local system. The city feeds waste into a plasma gasifier and runs its trucks, power and heating on the output. It competes with nobody because it owns its own trash, gasifier and utilities.
- Many facilities burning biomass today are converted coal plants, which is cheap to do and, he says, better in some ways and not in others.
- Gasifiers are not new technology. He dates the device to the original Siemens in 1850 and notes industry has used them ever since.
- On pure removal, he names Charm Industrial, which pyrolyzes biomass into an oil and injects it back into an oil field, and Running Tide, which grows kelp on strings and sinks it. Others are burying trees in brines, which he calls pickling biomass. Yale’s forestry school received a large grant to study the approach, mostly looking at ocean plankton, and buyers including Stripe and the Frontier initiative are paying for it.
- Bioplastics get a qualified endorsement. Total global plastics production is around a billion tons a year, so he calls the entire plastics market barely climate relevant; you cannot balance the atmosphere on yoga pants and hoodies. He still favors it as a bank shot, for displacing fossil feedstock and for drawing people into the topic.
- There is no global commodity market for waste biomass because there are no standard definitions of sustainable biomass or of how it is harvested and converted. Ethanol and biofuels do trade with real price discovery, so the two sensibilities coexist awkwardly.
- Highly localized deals can still stack economics: tipping fees for taking waste away, plus a separate environmental benefit such as reducing wildfire fuel, on top of the product value.
06Claims worth citing
All figures as stated in the episode released 2024-12-02. Kann notes at the top that the conversation was recorded some time earlier, so the figures may be older than the release date suggests. Carbon removal prices and company status move quickly.
- Using waste biomass could address on the order of 2.5 to 5.5 billion tons of carbon dioxide. The sentence is garbled and does not state whether this is annual, nor whether it means carbon removed or emissions avoided, and he sources it only as “a study we did,” so the figure should not be quoted precisely without finding the study. unnamed study he worked on, cited by Friedmann
- California has roughly a hundred million dead trees, concentrated enough to be a usable feedstock. Friedmann
- About 6% of Germany’s electricity comes from biomass through the gasifier-to-syngas-to-turbine route. The phrasing leaves it unclear whether 6% is all biomass power or only the gasification pathway. Friedmann
- The carbon-price crossover at which burying the carbon beats making a product is about $60 a ton for some systems, and at roughly $100 to $120 a ton covers pretty much everything. Friedmann
- There are about 42,000 airports worldwide, all with fuel depots and trash nearby, which is his scalability argument for aviation fuel. Friedmann
- Total global plastics production is about 1 billion tons a year. Friedmann
- Meaningful aviation decarbonization implies tens of billions of gallons of fuel and, by Kann’s framing, millions upon millions of tons of biomass. Kann and Friedmann
- Charm Industrial expects to remove carbon more cheaply than direct air capture and more cheaply than policy instruments such as the low carbon fuel standard or European carbon taxes. This is the company’s expectation as relayed by Friedmann, not a measured result. Charm Industrial, cited by Friedmann
- A jet fuel facility wants roughly a twenty-year feedstock supply locked up before it is built. Friedmann
- Gasifiers date to the original Siemens in 1850. Friedmann
07Where it’s contested
- Scarcity is the main disagreement, and it is between host and guest. Kann presses the competition framing repeatedly: a ceiling on waste that pushes operators toward dedicated crops the way corn ethanol did, aviation fuel that cannot be replicated hundreds of times, a limited supply to be allocated. Friedmann accepts almost none of it for the next decade or so, saying he is less worried about near-term supply, that there is far more waste biomass than aviation fuel alone would consume, and that we have not come close to the limits. He does agree the limits bind eventually. Both halves are his position, and the note should not be read as either one alone.
- Best use is explicitly a values question. He says three times that reasonable people can disagree, and lays out the competing objectives directly: maximize economic growth, remove the most carbon, or serve the communities where the waste is. He states there are no clean answers.
- The company disclosure. Friedmann volunteers that Carbon Direct has invested in the biomass-to-chemicals company the transcript names as Soligen before praising that pathway. He also distinguishes pure-removal companies from firms pairing energy with capture, naming Drax and a biohydrogen-with-capture developer.
- Company cost claims are forward-looking. Charm’s expectation of beating direct air capture on price is prospective, and Friedmann frames the whole emerging removal sector as something we will “learn enough to figure out whether or not these are truly scalable.” Nothing here is presented as demonstrated at scale.
- Biochar’s benefits are double-hedged. Improved crop yields and stored carbon both come with “under the right circumstances,” and the episode does not say what those circumstances are.
- The unresolved definitional problem. He calls the question of when a waste stops being a waste complicated and vexing, and separately notes that the absence of standard definitions for sustainable biomass is what prevents a real market from forming. Neither gets an answer.