Bio-coal: A renewable and producible fuel from lignocellulosic biomass | Hacker News Reader

Bio-coal: A renewable and producible fuel from lignocellulosic biomass

advances.sciencemag.org

90 pointsrch75 comments

I've been learning about biochar/syngas production from biomass.

It turns out there's methods that range from 'burn slash in a giant metal bucket' to large industrial gassifiers for producing biochar.

There's a part of me that wants to exit the tech sector, buy a couple hundred acres nearby, live modestly, and tinker with biochar production/sequestration.

Drying plants in the sun is a surprisingly effective way to heat a building, I grew up with it.

The problems are: burning wet stuff is terrible (surface wetness isn’t bad, it’s the moisture inside the biomass that causes problems.) Secondly you can’t just straight up burn it because you’ll get a lot of heat that you don’t need so you’ll usually burn it in cycles and you’ll get a lot of soot at the beginning and end of the cycles so you need to either wash the exhaust or make sure you don’t have nearby neighbors downwind (in places like this that means within a quarter mile or so.)

For sure, excess heat is something that is interesting to explore.

Oregon Kilns are basically just a big metal bucket that burns top down and produces biochar, but burns off the syngas.

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/newsroom...

Other systems try to capture the syngas/bio oil to generate electricity or capture the heat for heating/other uses.

One of the more interesting approaches toward wet biomass utilization is Hydrothermal Liquifaction

https://en.wikipedia.org/wiki/Hydrothermal_liquefaction

Basically you dump the wet biomass in a high pressure medium temperature reactor, and the water content of the biomass becomes supercritical, then acts as a solvent to break down the biomass into an usable crude oil (fairly similar to fossil crude, but with more oxygen content). This crude can be used directly as a fuel, or it can be upgraded (hydrogenated) into graded fuels like gasoline.

I met a guy who made biochar on the woodlot of someone he had an arrangement with - woodlot owners are always looking for new ways to monetise their lots, you may be able to tinker with biochar production/sequestration without the big upfront investment, this guy did it with a few weekends (and free labour from people who wanted to learn the technique) a year.

It’s important to note that (although I only skimmed it and am not a professional chemist) they only talk about hydrocarbons up to 6 carbons long (hexane) where coal/coke from the ground can have much longer hydrocarbons (what paraffin wax is made of.) This is because the hexane comes (probably) from sugar molecules (or monomers in things like cellulose) which are chains or rings of six carbon atoms (with other stuff bonded to them.)

It’s possible to lengthen the hydrocarbon chains but it’s very expensive.

EDIT: yeah after reading more carefully they’re doing what I thought (side note: the dick bar was pretty annoying, at least it goes away when you scroll down but coming back when scroll up and covering the text I was trying to read is just dumb.) They’re drying/dehydrating the biomass by heating it without oxygen and then distilling off the VOCs. Then they take the remaining gunk, crush it up, sift it, and dry it.

Although biofuels prevent consumption of fossil fuels, they still contribute to CO2 emmissions. Another side effect is that the land resources used to grow those biofuels are consumed. Also they lead to food prices increase and shortages. The good thing is when the raw material is made of leftovers from normal food oriented farming. However when farmers replace corn cultures with rapeseed that's bad.

That’s exactly why newer biofuels rely on sources that don’t require high investment crop land — e.g. switchgrass and other “weeds”. You could also plant switchgrass in highway medians, for example.

This doesn’t make sense to me.

First, the CO2 released from burning farmed plants does not increase the CO2 in the atmosphere. It’s a cycle.

Second, climate change will also cause food prices to increase. There is going to be an equilibrium point at which the increased cost of food due to land use changes outweighs the benefit of reduced emissions, but that point is almost certainly not zero.

In theory, farmers could replace corn with rapeseed at no cost to consumers if doing so mitigates climate change, the main problem is that the net cost of doing so needs to be averaged out over decades :(

On your first point, that is not quite correct. While the CO2 released will eventualy come back, it takes an enormous amount of time. It may be a cycle but what matters is the CO2 concentration in the athmosphere or more precisely the radiative forcing at a given time.

it takes one growing season for the rice, wheat, sugar cane, and soybean they were using.

If I burn a plant that contains 10 kg of carbon and then grow a plant that contains 10 kg of carbon then in terms of carbon in the atmosphere it should be a net zero effect. Plants take carbon out of the atmosphere to grow after all.

> If I burn a plant that contains 10 kg of carbon and then grow a plant that contains 10 kg of carbon then in terms of carbon in the atmosphere it should be a net zero effect.

No, because the plant you burned would have pulled more CO2 from the atmosphere if it had stayed alive, there's plenty of CO2 around already to feed other plants in the mean time. So the net effect is negative. If you can't grasp the logic, think about what happens if you burn all the plants. Some will grow back, but not all.

That plant would pull in more CO2 and increase its own biomass based on it. When that plant then dies two-three-five years later then all of that carbon gets back into the atmosphere anyway.

>If you can't grasp the logic, think about what happens if you burn all the plants. Some will grow back, but not all.

The only way they don't grow back is if desertification happens or humans start using that area. Otherwise, the plant life returns on its own. Chernobyl is overrun by plants.

> When that plant then dies two-three-five years later then all of that carbon gets back into the atmosphere anyway.

No. If it fully decomposes at some point, arguably. But plants are eaten by various organisms (= C becomes part of the organism), are used for building houses, become fossilized. All of these make these "cycle" claims invalid.

> The only way they don't grow back is if desertification happens or humans start using that area.

No. Plants can also become extinct (= no seeds survive) or stop growing in some places due to more aggressive competition.

>But plants are eaten by various organisms (= C becomes part of the organism), are used for building houses, become fossilized. All of these make these "cycle" claims invalid.

That organism will soon die and decompose as well. Fossilization is rather uncommon nowadays. The only one of those where we could and do put a lot of carbon is buildings. However, even those end up rotting over time.

Most of the coal formed at a time where lignin didn't break down. We don't live in such a time. We can't repeat the same process. It doesn't really matter whether the carbon is released back into the atmosphere in 2, 5, 50, 100 years. It'll still be released and contribute. Stashing carbon into those forms is not a solution.

That’s ridiculous. We’re talking about plants specifically grown, using agricultural techniques, for biochar or food.

The entire industry is predicated on growing a predictable mass of plants per unit area. If we can’t do that then we have much bigger problems than the CO2 cycle.

> We’re talking about plants specifically grown, using agricultural techniques, for biochar or food.

And you believe this can be done in a CO2-neutral way, even if we assume the CO2 is recovered quickly and never accumulates in the atmosphere? Ridiculous, modern agriculture is far from even "low emission"...

>First, the CO2 released from burning farmed plants does not increase the CO2 in the atmosphere. It’s a cycle.

But you can say the same about burning coal.. That CO2 will eventually be consumed by plants and stored there as carbon.. only it will take quite some time

Except it won't, dead plants decompose and release their carbon back in to the atmosphere whether you burn it or not. Coal comes from an age where atmospheric carbon was much higher and nothing had evolved to decompose wood, digging it up and burning it means a net increase, growing something and burning it is net neutral.

Technically it will, because there are geological processes that more or less permanently remove carbon from the atmosphere, but they take geological time (tens of thousands of years).

Coal was laid down well before the current atmospheric equilibrium. The CO2 in coal and other fossil fuels has essentially been removed permanently from the atmosphere.

Until we dig it up and burn it, anyway.

> First, the CO2 released from burning farmed plants does not increase the CO2 in the atmosphere. It’s a cycle.

Widespread nonsense.

The CO2 emitted through burning plants does not magically turn into plants again. Plants have limited capacity to draw CO2 from the atmosphere and there's plenty of that around already, indistinguishable from "industrial" CO2. Any CO2 added through fires increases atmospheric CO2, any plant burned doesn't increase, but decreases the chances of CO2 removed from the atmosphere in the future.

Just charcoal the biowaste, and bury it.

Much less tech needed, and it actually reduces co2 not just circulates it.

Profit is via increased crop yields.

Bio-coal is charcoal, just produced by different means than charring the biomass. Typically, bio-coal production manages to convert more of the carbon into coal, while less of it is burned.

Fairly sure GP's point was that sequestering the resulting carbon is a better move than burning it back into the atmosphere.

Meeting CO2 goals requires removing carbon actively from the atmosphere, and drastically reducing our use of CO2-producing energy sources. Burning bio-coal does neither of these things; burying it accomplishes the former, and is at least not working against the latter.

> Meeting CO2 goals requires removing carbon actively from the atmosphere, and drastically reducing our use of CO2-producing energy sources.

No. Either one could be sufficient alone, just as you can lose weight either by exercising more or eating less alone, though generally the combination is better.

For removing carbon from the atmosphere we could dump olivine sand into coastal waters where it would sequester carbon as it was weathered. If we want to reduce our use of CO2 producing energy sources without massive declines in quality of life or vast environmental damage there’s only one choice, nuclear.

>If we want to reduce our use of CO2 producing energy sources without massive declines in quality of life or vast environmental damage there’s only one choice, nuclear.

Unsubstantiated claim detected.

Solar, wind, hydroelectric, and geothermal are all cheaper than nuclear (and even coal) for new generation capacity. That includes capital, operation and maintenance, and transmission costs. See tables starting on page 8 for the numbers (https://www.eia.gov/outlooks/aeo/pdf/electricity_generation....).

In that vein I reduced the amount of CO2 my car produced per year by one simple trick. I moved closer to work. I was commuting 8000 miles a year. Now I'm commuting 4000 miles. And it's 10 minutes to work instead of 30.

What about storage cost to make it viable for base load?

Use surplus wind power at night to make hydrogen via electrolysis, and keep hydrogen-burning gas turbines or fuel cells or whatever around to fill in gaps.

Solar requires the clearing of huge amounts of land, with the associated destruction of wildlife. To the best of my knowledge there has been no progress made in figuring out what to do with solar panels at the end of their working lives either and they all use lots of toxic heavy metals. Wind doesn’t leave lots of toxic waste but it does kill millions of birds and bats a year, disproportionately effecting large birds with long generation times, most of which are predators like eagles. Hydroelectric is at least less soul crushingly ugly but the environmental effects of flooding huge amounts of land are hardly positive. It’s also basically played out in developed countries. All of the suitable sites for hydroelectric power have been developed. Besides turning mountain ecosystems into lakes HEP is hideously dangerous in ways that are basically unavoidable. The failures of the Banqiao and Shimantan Dams killed 170-230K people in 1971[1]

Solar, wind and hydro all entail a lot of damage to the environment, far more than is necessary from nuclear, just because they require much greater areas as they’re less energy dense.

I don’t deny that nuclear is more expensive on those grounds. I just think that relative safety is more important. So by the most expansive counts Chernobyl killed 4,000[2] people while air pollution kills about 7 million a year, every year[3]. Germany’s closing of its nuclear power plants has lead to an additional 1,000 deaths a year[4]

Nuclear is safer than any alternative source of energy, wind, solar and hydro included. If you include those costs nuclear looks amazing in comparison[6].

[1]https://en.wikipedia.org/wiki/Banqiao_Dam

[2]https://ourworldindata.org/what-was-the-death-toll-from-cher...

[3]https://www.who.int/mediacentre/news/releases/2014/air-pollu...

[4]https://www.washingtonexaminer.com/policy/energy/german-nucl...

[5]http://papers.nber.org/tmp/26395-w26598.pdf

[6]https://www.statista.com/statistics/494425/death-rate-worldw...

The bird death from wind power thing is basically rubbish:

https://www.bbc.co.uk/news/science-environment-48936941

Wind power kills fewer birds per unit energy than coal, and it kills orders of magnitude fewer birds than domestic cats, which we're apparently fine with.

Plus, the big growth in wind power will probably be offshore: there's more wind and fewer NIMBYs there. There is also a lower density of birds.

Wind turbines kill animals cats don’t. You think a cat is going to kill a golden eagle, a vulture or a stork? Different animals have very different generation times and life cycles. Wind power kills fewer animals per KWH than coal but it kills different ones and that matters.

> Fatalities at wind turbines may threaten population viability of a migratory bat

> Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus), the species most frequently killed by turbines in North America. Using expert elicitation and population projection models, we show that mortality from wind turbines may drastically reduce population size and increase the risk of extinction. For example, the hoary bat population could decline by as much as 90% in the next 50 years if the initial population size is near 2.5 million bats and annual population growth rate is similar to rates estimated for other bat species (λ = 1.01). Our results suggest that wind energy development may pose a substantial threat to migratory bats in North America. If viable populations are to be sustained, conservation measures to reduce mortality from turbine collisions likely need to be initiated soon. Our findings inform policy decisions regarding preventing or mitigating impacts of energy infrastructure development on wildlife.

Not necessarily

Put the panels on lakes, reservoirs, and at sea, and of course, roofs.

Particularly for reservoirs, panels can provide shade for fish, and theres the potential for pumped-hydro storage with tiered reservoirs - or at least substitute hydro output when the sun shines.

As for toxic metals in solar panels, they're locked away in the panel. Rather like vitrification for nuclear waste encapsulation. Just make some solar-panel-only landfills, which will become future toxic-heavy-metal mines - this stuff all came out of the ground, it can temporarily go back.

Nuclear solves nothing. It has its role as a stop gap but renewables are cheaper safer and easier.

The main challenge in a decarbonized energy sector (including heat!) is not week to week or day to day variability but season to season. That's best solved with power 2 gas and storage whether the major source of energy is nuclear (leaving nuclear reactors on idle for half the year is expensive) or renewables.

Germany has the most expensive electricity in the world (excluding Diesel powered islands). Electricity in neighboring France is a third or so of the price. Is that because France gets so much more sunlight?

That's vastly inaccurate. It is correct for household prices, but for energy intensive industry the difference is much smaller, something around 2 cents.

Besides what the sibling pointed out: choices and subsidies, determine consumer prices. Coal subsidies still are vastly larger than renewable subsidies world wide. Compare the price of new wind and new nuclear stations.

That admittedly doesn't give you total system cost, but you need solid models for that anyways, as electrification of mobility and heating will completely change demand structure in the electricity secto.

The consumer price of electricity in Germany and France tells you absolutely nothing about any of that.

I totally forgot about coal subsidies! Those must be the reason why German electricity was cheaper 20 years ago, when we still mined hard coal in the Ruhr area.

You seem to not be very well informed and unwilling to learn.

In the UK a low carbon tax rendered coal completely uneconomical and they smoothly phased out coal without any price hikes. The guaranteed price for rendering the new Hinkley Point nuclear power station economically viable is much higher than the price of new wind/solar, and higher than the economically optimal system cost of a 100% renewable system.

Selectively citing macro facts without considering the complicated details is no way to get to an understanding of the system constraints and possibilities, or the true cost structures. You can't avoid detailed modelling of the trade-offs involved.

> You seem to not be very well informed and unwilling to learn.

Cute.

I live in Germany. Nothing you write will change the fact that I pay 30 Euro-cents per kWh. Nor will it change the fact that people in France pay much less and people in Poland pay even less than the French. Nothing that happens in the UK has any impact on that, and neither do you models of trade-off. Your models also don't change the amount of CO2 emitted per capita, which is twice higher in Germany compared to France.

7ct of that is power generation. The rest is taxes and other things.

Nuclear does massively reduce the French CO2 Footprint.

And French taxpayers will pay for storing the waste forever.

That’s only true for household electricity prices and is solely explained with the high taxes. Electricity prices without taxes are only a bit higher than the EU-average.

https://ec.europa.eu/eurostat/statistics-explained/index.php...

No, it is because the politicians have decided that the largest industrial consumers of electricity should be exempt from the EEG fee. Instead of subsidizing renewables the end result is that the EEG fee is primarily a heavy industry subsidy at the expense of residential consumers.

The EEG fee is anti efficient because of the exemptions. As money more is invested into renewables the market price goes down. Renewables are guaranteed a fixed payout per kWh so lower market prices mean that the EEG free has to be increased but since heavy industry doesn't have to pay it, the industrial electricity costs are trending down to 0 for them. When a large consumer is paying nothing then someone else has to cover that shortfall and residential consumers get no exemptions so they are the ones who have to pay for everything.

Nuclear is great, but at the moment, it takes a very long time - several years - and a huge amount of money to bring a plant online. We won't be able to build nuclear capacity fast enough to hit 2030 goals.

I think we should absolutely be developing new nuclear plants. Hopefully we'll get designs which are cheaper, faster to build, and even safer that current ones, and then we should build loads of them. But in the next ten years, we just need to build all the offshore wind we possibly can.

There are many carbon-capture options.

The olivine plan seems to me one of the more unrealistic ones.

But to be sure, we will need to capture, in addition to switching to clean production, unless we switch a decade or more ago.

I agree nuclear can play a big role in clean production, particularly that huge reactor in the sky.

Not sure that's true-- From the paper it seems like they are making bio-coal by distilling the liquid fraction produced during the charring process (the bio-oil). Bio coal is more like a very dry, solid tar than a charcoal.

If it’s prepared with renewable/carbon neutral processes then using it to generate heat will be renewable/carbon neutral. If it’s used to replace petrochemicals instead of heat (which they pointed out was uneconomical anyway) it sequesters carbon, so it’s a good thing.

It’s always better to have options.

The paper talks about this option (well, burying the output of this process).

It's carbon negative to use it as a soil additive, but you don't get to burn the bio-coal for energy, so it's slightly less profitable.

I guess you could do a bit of both and be exactly carbon neutral.

In the paper they are actually producing both biochar and biocoal. The biochar is the solid fraction produced during pyrolysis. The bio-oil (volatile hydrocarbons) are then further distilled to produce biocoal. By tweaking temperature and process parameters they can likely optimize for production of one or the other.

This seems like a nice improvement for processing biomass waste

- less of the input energy wasted compared to traditional charcoal production.

- retains coal advantages compared to less processed biomass, namely higher heating value meaning cheaper to transport, and easier to store (doesn't rot if it sits in a pile outside)

However, as a side note I'm very sceptical wrt bioenergy. Using biomass waste for energy is fine if there's no other use for it, but growing biomass for energy production really isn't. Next to climate breakdown, the most serious ecological problem we're facing is biodiversity loss, largely due to conversion of wilderness to farmland. We really need to get past the idea that every hectare of land has to be put to "productive" use. Much better to produce our energy with wind, solar, hydro, geothermal, and nuclear, and rewild nature to the extent possible.

While I don't disagree with you, it's worth noting that wind, solar, and hydro all have major impacts on nature. As long as everything goes to plan, nuclear seems to have a limited impact on nature. I'm not sure about geothermal.

I wonder how the potential energy output of a solar farm compares to a biomass farm.

Main problems with bio fuels of any kind is hard to avoid bad actors finding externalities and just burning non waste, and it’s still burning. I non market or very mature regulation would be needed to make it a good alternative but even then the scale of energy is very small last I read.

I’m still skeptical on nuclear due to its low risk but severe outcomes when it goes wrong, build time and end of life issues/economics (solar might have end of life issues too, less so wind it seems). Solar and wind imo still winning on real world offsetting thanks to their relative simplicity for rolling out at scale. A hydrogen based economy would also marry nicely with excess production at peak times.

> nuclear seems to have a limited impact on nature

I mostly agree, but don't forget about the mining operations:

https://phys.org/news/2019-05-uranium-heart-kakadu-cleanup.h...

https://goo.gl/maps/8NVrpwSy7mCmJzq69

https://goo.gl/maps/ZdKKHc4jHBBrMcio8

And in the USA: http://cleanupthemines.org/facts/

Even including uranium mining, nuclear power has lower material throughput than, well, pretty much any energy source including wind and solar. With wind and solar you're harvesting a pretty diffuse energy source so lots of (mostly) steel and concrete needed per unit of energy produced over the lifetime of the plant.

Also, with a closed nuclear fuel cycle we could reduce the amount of fuel mining by a factor of 100 or abouts. Heck, we could shut down mining for a couple of centuries while we burn all the uranium we have already dug up. So far there's little interest in that, though, as uranium is pretty cheap.

Heck, we could shut down mining for a couple of centuries

It seems to already be heading that way.

Last week it was announced that the uranium mine in Grants, New Mexico will not reopen because the price of uranium is so low.

Covering about 2% or so of the world with solar panels and wind turbines would provide for our energy needs. Biomass would require a lot more land.

High intensity biomass farming requires an order of magnitude more land area than solar.

https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/cobi...

Bio-coal is possible, and may be economically viable (especially when produced from biowaste as here), but only makes sense for an extremely brief transition window. So these guys need to go from the current five-gram scale to the estimated one million tonnes per day scale in less than five years. Maybe in China that's possible.

I'm not sure whether I agree with your timeline. Coal will likely remain useful for a variety of industrial processes, like steel production.

But that's because of it's usefulness as a chemical precursor (i.e. carbon) rather than because it was worth it to burn for straight heating energy in a power plant.

I am pretty much okay with (or at least resigned to) petrochemicals/coal being used for the next 30 years to produce chemicals and other products. Burning it is a waste of a very useful chemical feedstock.

The lowest value (and by extension least valuable) thing you can do with a material like coal is burn it. If it's used because of it's properties other than it's fuel content of course it's value is higher and economics will make it more compelling. These are entirely different markets in size and kind.

Even with steel there's direct reduced iron and electrolytic steel production is already on the horizon.

Is this what you're talking about?

https://www.scientificamerican.com/article/cleaner-cheaper-w...

Looks like another great way to use excess renewable power when the grid is underutilized but the wind is blowing and the sun is shining. Build enough of these to matter and you could probably get away with a fair bit less battery storage as long as you still have natural gas peakers.

http://www.hybritdevelopment.com

"If successful, HYBRIT means that together we can reduce Sweden’s CO2 emissions by 10% and Finland’s by 7%."

Nice! I saw a great presentation from some researchers that figured out how to make electrolytic Boron as well using molten oxide electrolysis.

http://dspace.mit.edu/bitstream/handle/1721.1/64889/34540560... (warning, link to a thesis)

How old are you? ;-)

Why?

" I saw a great presentation from some researchers " and the paper you linked to was from 1940. :-)

Haha, I didn't notice that actually. The presentation I saw was last year by some folks researching the topic who found a way to make it economical enough.

I could have sworn the name was the one I thought but guess I am too old to have a good memory =)

It's not really all that conducive to starting and stopping depending on energy prices. We already have that same capability with Aluminum and I've never heard of any Aluminum plant shutting down during the day and picking back up at night. Those cells and keeping them running are going to be expensive enough that I doubt it would make economic sense to stop production unless power is just absurdly expensive. The price of iron isn't about to fall through the floor and the price of electricity isn't going to skyrocket so even if power was free all night I'm still not sure that it would be worth it to save a little on electricity costs in the day and miss out on a chunk of production.

I think the much bigger impact is going to come from deferred charging of battery electric vehicles. The transportation sector accounts for 28% of total US energy consumption. Electric cars are getting capacities large enough that range is close enough to on par with traditional ICE vehicles. It's already commonplace to shift around when you fill up at the gas station by a day or so, with electric vehicles rather than having to work around personal schedules to refill you can just leave it plugged in when parked at home and let it charge whenever it's appropriate so long as it meets basic constraints like e.g. make sure I have at least 60% charge by time to leave for work.

If a large portion of 28% of total energy demand can be deferred a bit that should do a lot to increase the flexibility of demand to accommodate the variability of renewable power sources. And that doesn't even touch on repurposing spare capacity as a distributed energy storage mechanism. If the margins of buying power at cheap costs and selling it at peak demand can more than pay for the degradation of the battery and any conversion inefficiencies then that's a ton of energy storage capacity right there. It already makes economic sense for utilities to use some battery energy storage systems today so I can't imagine it would be impractical when the capital costs are reduced to nothing and it's just the operational costs to consider.

Before coal, there was charcoal; the process works perfectly well with it. We switched because the energy-ROI and logistics are much easier than the manual charcoal production process was.

Your comment made me realize that I didn't fully understand the difference between coal and charcoal. I assumed they were functionally equivalent, just of a different origin. But apparently charcoal is just carbon, and coal contains all kinds of other substances which can be used to create rubber and other synthetics. As a result burning charcoal is much cleaner (though making it isn't), and coal has uses far beyond merely setting it on fire.

while we're on cellulose, anyone heard of homelab-scale methods to produce cellulasic enzymes ?

climate crisis, hello... fossil fuels are a dangerous anachronism to be gotten over, hello...

(renewable or not, net carbon emitter and HOW...)

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