So you want to build a carbon capture company | Hacker News Reader

So you want to build a carbon capture company

caseyhandmer.wordpress.com

194 points_Microft175 comments

If a machine were invented that scrubbed carbon from the atmosphere and turned it into useful food, construction materials, animal feedstocks, and fibers, all while rebuilding topsoil, it would be on the cover of every tech magazine in the world and its inventor would be a celebrity millionaire. Yet I’ve never seen a tree on the cover of Wired.

https://hipcrime.blogspot.com/2012/06/vertical-farms-and-lab...

Sometimes we overlook the simplest approaches. We should plant trees. Lots of them. It's not a perfect solution, but it's the simplest, can be adapted to every environment, has costs that are relative to local economies, doesn't depend upon global supply chains, doesn't require human maintenance after initial planting, etc.

> Sometimes we overlook the simplest approaches. We should plant trees. Lots of them. It's not a perfect solution

That's because it's not a solution at all:

https://www.wired.com/story/trees-regenerative-agriculture-c...

Trees alone might not be. However, photosynthesis is the answer. Plants exude sugars and carbohydrates, made from atmospheric CO2, into the soil feeding massive amounts of bacteria and fungi(carbon). The bulk of carbon in the soil comes from plant exudates, not plant matter. As long as this ecosystem is healthy the carbon stays in the soil. When the soil ecosystem is healthy plants are healthier which makes everything up the food chain healthier. The majority of our crop and pasture land soil is dead. The previous year's carbon that was pumped into the soil by plants is released when tilling happens in the spring.

We need to stop tilling and grow diverse, more than 8, species wherever we can.

Five tenants of soil health https://youtu.be/uUmIdq0D6-A

NASA CO2 https://youtu.be/x1SgmFa0r04

Could creating algea flowering allow for large scale photosynthesis binding?

This is all or nothing thinking. No one solution will solve everything, but trees plus emissions reductions are probably the two easiest and biggest.

Its not about that. Its about the cold hard reality: Planting tree's will not be a significant factor in fixing climate change. Its not that its worthless, its that its not worth discussing relative to the other items on the list. Because (for arguments sake) of the 20 or so other ideas we have for fixing climate change, we need roughly all of them to work, and they will all have 100-1000x the impact of planting tree's. And we don't have a concrete plan to get them going. We need focused discussion and action and a lot of innovation.

Your link claims the 1 trillion tree estimate is wrong. But it doesn't propose an alternate number.

Here's a back of the envelope calculation: a tree absorbs about 48 pounds of CO2/year [1], which is 22kg. So, one trillion trees absorb 22 GT/year. The world puts out 36 GT/year (or about 50 GT of CO2-equivalent if you include methane and other greenhouse gases). One trillion might not be enough, but 2 could do the trick.

[1] https://www.usda.gov/media/blog/2015/03/17/power-one-tree-ve...

Isn't the issue with trees is that they release the carbon back after they die and decompose? You have to actually sequester carbon somehow. No idea how easy it is to do with trees (presumably you'd have to cut them and put them somewhere they don't degrade?).

In terms of getting the most capture for your buck, it seems like you could just harvest the logs, ship them by rail to an arid area, pile them loosely to facilitate drying, and (optionally) treat them with an anti-fungal agent.

Right, trees provide a buffer. If you can plant faster than the trees are dying, you gain ground.

And as large scale planting projects have shown: planting trees fast and getting them to survive in a cost effective way is a hard problem.

Technically you need to plant trees faster than they rot, not faster than they die.

All the trees that were cut down to built my house are not rotting - that carbon is captured and out of the system until/unless my house is burned down or left to rot.

It's funny to think - right now "green building" tries to minimize the amount of wood in a structure, but are we approaching a future where green building means locking up as much wood product in a structure as possible, to get it out of the carbon cycle?

...can we build houses with them?

Isn't that offset by the fact that trees replicate?

As someone currently dabbling in the space, this is great reality checklist for a majority of research papers (and, unfortunately, a large majority on commercial endeavours, too) on the topic. The author makes a solid delivery on his outset promise.

It just might help to shed some light on something akin to the blockchain/machine learning hypecycle bubbles amongst startups.

This checklist would (with a few minor adaptations) also work great for many other types of "so you want to start an X company". Very thorough indeed.

Armchair strategizing on the topic I know nothing about (but it's fun to think about!):

Constraints:

- C removal requires lots of energy (can't avoid thermodynamics)

- electricity on that scale is either expensive, dirty, or both

Additional concerns:

- cheap/clean energy is intermittent (and still a small percentage)

- excessive electricity is as bad as not enough electricity

Solution:

- build lots of new (safe and cheaper) nuclear power plants

- hook them up to the grid and use them as peakers (!), and using them for C removal on off-times

This:

- provides cheap and clean (from the perspective of C footprint) energy

- solves the intermittency problem of wind/solar

- provides abundant energy for C removal

Assumption: that safe nuclear fission power plants (using Thorium, MSR, .. reactors) are feasible and can be built on the cheap (for some value of "cheap")

I really like your idea on a personal 'neat' would-be-nice level, but it makes one of the most common mistakes in the nuclear<->climate-change discussion: time.

The development of next-gen/thorium/msr/whatever from first-commercial-success to repeatable-and-therefore-cheaper is, even in a highly optimistic scenario, a 30+ year proposition. I fervently believe we should fund and invest in that r&d, but even if it pans out (which I bet it would, but you have to acknowledge its our guess), its simply not a part of our "it is time to act now" timeline.

I do this all the time too, its largely a part of the fact that many of us are middle aged men now. We were taught to think of, and mentally frame this as, an "over the course of the next several decades" type of problem. In which case a nuclear solution was fairly obviously the best path available.

The problem is we didn't take that path. And the decades have passed. So while we should start down that path now ASAP from an r&d/investment perspective, it is almost completely a distraction today from a "net-zero in 20-30 years" perspective.

I guess what I'm mostly trying to say is, whenever engaging in the climate-change/energy-generation-mix "debate" these days, try to mentally factor in time as one of the top constraints in your model. Here's an IPCC chart of four example scenarios that show you what the slope of the curves need to look like: https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SPM3...

Yes, if we rapidly decarbonize to renewables and figure out the storage issue, we don't need nuclear. And we should certainly attempt that. But if we overshoot, like in that P4 scenario, we're going to need massive carbon capture down the road, and nuclear fits quite well into that scenario.

Also, if storage remains expensive at scale, so that wind/solar gets very expensive past 80% market penetration, nuclear would be a low-carbon way to fill in that last 20%. It doesn't do away with the need to roll out wind/solar as fast as we can, but it helps us with the hard part later.

Nuclear also may be well-suited for industrial applications requiring process heat instead of electricity.

Nuclear isn't cheap. Molten salt thorium reactors are seriously not cheap, and if you can handle molten salt that well, you can use it to store solar power and release it later and solve the intermittency problem.

You'll have to pick two among fast, safe and cheap.

For the specific application of carbon capture (CC), electricity intermittency is not a big deal; just cover a square mile with PV panels and capture carbon while the sun shines. (Assuming you have a viable CC technology in the first place.)

I have a hunch that there is no artifical process that could possibly compete with what nature already has. The answer is plants. So the solution would be a way to sustainably grow a lot of plants in a short time.

But another main factor is the destruction of the densest of those ecosystems, the rain forest on a large scale.

That is my answer, stop humans/companies/countries from destroying the rain forest on a large scale (I'm looking at brazil and neighbors) and think of ways to rebuild lost rainforest in an efficient way. I am going to wager, from the knowledge and experience I gathered in my years of living, there is no other solution that is sustainable.

my understanding from watching that crazy netflix sea documentary is that algae is the go to for oxygen production / carbon capture...anyone have ideas on which is the more important case?

Algea is only a co2 battery unless you can capture it and store the algea without it fermenting. If you just grow it in the Ocean, you need to increase the Ocean's algea carrying capacity and form it thus into a battery because dead algea gets fermented by bacteria into co2 and methane again. Also the ocean's carrying capacity for algea is currently ever decreasing due to oceanic acidity increasing from co2.

Artificially growing algea in pools and using that to make fuel/ pump it underground so the fermentation products don't get released is not nearly efficient enough to be viable. Ironically this usually also uses fertilizers which are dependent on the fossil fuel industry.

The ecosystem is more or less in a balance. Forests that are cut down will become forests again. Plants already grow pretty much everywhere where they can grow. It's still not enough.

We've spent over 200 years pumping carbon into the atmosphere from a source we can't return it to. No amount of growing forests is going to fix this issue without being able to turn those forests into carbon that's in the ground. We need to get carbon out of the carbon cycle. The natural life of plants doesn't do that.

Edit: we might be able to do it, if we can somehow turn land where forests don't grow into forests.

The system will eventually return to balance, for example few million years after all humans die out. The question is if we can keep it in such balance that allows humans to live. Maybe there's not enough space on Earth for all humans and everything they need to live + sufficient area of forests on top of that

> Maybe there's not enough space on Earth for all humans and everything they need to live ...

I recon the problem isn't what humans need to live but rather what many of them want to have.

Not only forests, but converting a desert, like Sahara, into agricultural land will help too. Same is true for ocean deserts, places where there is no upwards flow bringing nutrients from ocean floor to the surface, which is the majority of the ocean.

I think the math has been done for this and the CO2 captured by planting the Sahara would be offset by the increased warming due to the reduction of albedo effect. Which is crazy to think about.

AFAIK this was done simply by assuming the change of the color, without taking into account the change of cloud coverage, and clouds have a huge effect. So it can go both ways depending on how exactly we will be changing the climate of Sahara.

And there are many possible ways to control the climate in a smart way instead of trying to simply remove CO2. One possibility is to use ocean thermal energy conversion plants [1], to cool down tropical region of northern hemisphere, artificially re-creating conditions that cause green Sahara periodically. Aubrey de Greys new moonshot https://viento.ai/ is working on similar ideas.

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

You’re so close to saying the solution without getting there.

Fast growing plants are probably the most effective carbon extraction we have. Problem is when they die they turn back into CO2.

So we should bury those plants before they rot. Our excess CO2 stems mostly from dead plants and animals that have been buried. Seems sensible to put some of our excess back into the ground.

I like the idea of sort of (but not really) making coal again in a fight against climate change.

In WV we have tons of old strip mine - we should fill them up with plants and bury it.

If we did something like that I imagine the biomass under the earth would compress over time and the land above would end up shifting and causing issues for anyone that wants to use it.

Edit - Daydreaming about this scenario and I am imagining trying to sell the idea of refilling the old coal mines with biomass to folks living in coal country. An interesting and funny situation.

Which requires digging. Which requires machinery at an industrial scale. Which requires large amounts of energy. Which makes it really hard for this to not be in the perpetual motion set of solutions.

You’d have to be extracting more carbon than your diggers consume (since even today I don’t think this has electrified and capable of running on solar). Your diggers are consuming concentrated carbon compressed from plant and animal biomass under high pressure and energy over millions of years. It seems highly unlikely just growing and burying biomass is sufficient. Additionally, I’m pretty sure the CO2 is just going to leak out in large quantities since, unlike the naturally sequestered CO2 we extract from the ground, you have bacteria that can break down the biomass and let the CO2 escape as a gas. Which means we have serious additional efficiency losses.

The only solution that could work for sequestration as far as I can tell seems like an industrial process powered by nuclear because it breaks the energy cycle completely to accomplish the task. Solar is popular but I’m skeptical that renewables are up to the task that’s required to undo several hundred years of fossil fuels being the engine of the world’s industrial progress.

I can't speak to any of the details, but this is definitely an interesting approach: https://www.cnn.com/2021/05/03/business/running-tide-kelp-ca...

The majority of carbon in the soil doesnt come from plant matter. It comes from plant root exudates. Plants pump sugars and carbohydrates into the soil to feed bacteria and fungi. As long as we dont poison or till the soil, the ecosystem keeps the carbon in the soil. Some of it will cycle. That is the way it is supposed to be.

Greater than 80% of farm land soil is dead. What little carbon that is built up in a season is released in the spring when the field is tilled.

No till, diverse cover crops, and animals (a complete ecosystem) stores immense amounts of carbon in the soil.

> No amount of growing forests is going to fix this issue without being able to turn those forests into carbon that's in the ground. We need to get carbon out of the carbon cycle. The natural life of plants doesn't do that.

Taking (sustainably harvested) wood from old trees which are close to dying anyway and using this wood to build durable (lasting decades) houses would be helpful. This would channel carbon from the natural cycle into an artificial reservoir made up of buildings.

Questions left unanswered:

- would this reservoir be big enough?

- is the rate of carbon fixation sufficient?

The US has a bunch of land. A thought occurred involving the US's surplus military personnel spending their days, after waking up from their barracks in some state in the west, tending to a massive bamboo garden, including cultivation, pruning, and disposal into giant pits. The Wikipedia article for bamboo even mentions its use in carbon sequestration prominently. Having looked into this before, though, I turned up a few sources that said bamboo alone has no net negative effect on atmospheric carbon, and might actually increase it.

What about cannabis?

It grows rapidly. The fruits (bud) are valuable and the remaining plant material can be compressed and buried.

This is the mission at Terraformation[0] (no affiliation)

[0]: https://www.terraformation.com/about

This definitely seems the most feasible. Sure, plants aren't particularly efficient, but they're also self-reproducing and self-maintaining, which is a huge bonus.

One interesting approach with plants is to pyrolise them to make biochar - essentially turn them to charcoal. You get a bit of hydrocarbon gas out of them, which you can sell to pay the bills (this is the biggest problem with any carbon capture - there's basically no way to pay the bills), and then you bury the pure carbon that you're left with.

I did a bit of research on this a while back and wrote up the calculations here:https://concretecuts.xyz/articles/biochar

Essentially we'd need to devote quite large amounts of land towards this if we wanted to compensate for our current emissions - something like 66% of the world's forests would need to be periodically cut down, with around 1% cut down and pyrolised each year.

You could probably get some easy wins with existing wood and crop waste - by my estimate we could capture 3% of global emissions just by pyrolising Europe's existing biofuel feedstocks.

Norway have been doing CC since 1996 from natural gas and pumping the CO2 back into the well. The first commercial reservoir (Northern light project) for pumping CO2 back into old oil wells will open in 2024. The drilling is finished and the capacity is estimated to 1.5 million tonnes of CO2 per year for this first project. There is not any capacity left now for new contracts, but they are planning for additional wells.

https://www.norskpetroleum.no/en/environment-and-technology/...

It would be far more efficient (since additional energy is used for all the actions around it all) to not bring up carbon from below ground in the first place. As long as Norway brings up new oil those actions are just marketing.

See the article we are talking about here. First you spend energy to bring up carbon. Then you spend more energy to get it back down again. The math does not check out. Not bringing up the carbon in the first place would have been far more beneficial for atmospheric CO2 levels.

Worse, they plan to do more of the oil-digging: https://www.reuters.com/article/us-norway-oil-environment-id... (this is dated Dec 2020)

"Norway wants to lead on climate change. But first it must face its legacy of oil and gas." -- "An expert explains Norway’s climate change paradox." -- https://www.vox.com/22227063/norway-oil-gas-climate-change

It might be possible to pull hydrogen from the ground, leaving the carbon in place. https://proton.energy/ claims to be trying.

As a Norwegian I agree we should phase out oil sooner. Like you say, not releasing the CO2 to begin with is the best option.

However Norway is not the sole oil producer. If demand is not reduced and other producers compensate for our reduction, then that won't really help the planet at all.

As such it seems reducing demand would be the best way. Not that easy to achieve on a global scale though, it would seem.

yes, that's what we all say

"He started it Miss, it's not my fault!"

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

Every Norwegian needs this illusion(Or livsløgn as Ibsen would have said) to sustain the idea of belonging to a nation that is up to something good.

Reality is that Norway is increasingly subsidizing it's oil industry in a way that is not sustainable - especially not economically.

Instead of investing in the future Norway is investing in old dying industries - our Corona package contains almost no investments in sustainable technologies even thought the economy is heading for a hard shock the next time the oil price takes a dive.

Reducing demand and reducing supply both help in getting the CO2 emissions down. A good start would be to just stop subsidizing the fossil fuel industry.

I feel confident that if Norway stops pumping oil tomorrow, it would be pretty devastating to our economy. I also feel confident that other countries would increase production in response. Is that just an illusion?

I absolutely agree that we should focus a lot more on making new jobs that aren't oil-related, and stop investing in oil like we do. Oil is most definitely not the future, and we should push hard to make a transition starting yesterday.

That's not at odds with what I wrote above though. Reducing climate change is a global game of prisoners dilemma.

I have a friend from Romania who works in your country...very hard and high cost of living... I personally would prefer your "economy" suffers some contraction so he can come home and help here while you guys "modernise" with all that oil money you have saved.... also your "global game of prisoners dilemma" metaphor (is disingenuous?) it ignores the real time reality climate cliff we are about to fall off... currently we need leaders not Stockholm syndrome followers... I mean isn't asking authoritarian regimes (Putin, MBS, Venezuela) to stop pumpinga pipe dream...?

> also your "global game of prisoners dilemma" metaphor (is disingenuous?) it ignores the real time reality climate cliff we are about to fall off

That's part of my point. Making an impact against climate change requires everyone to work together while sacrificing something, like the mutually best outcome for the prisoners.

However not following that path can be very economically beneficial to a country, at least short term.

Thus there's incentive to ignore climate change and not work together, like the example I gave earlier. If someone else will pump the oil that we won't and the oil is getting burned all the same, why should Norway take that hit? That's what the dilemma the prisoner has.

I mean, just look at how hard the delegations worked to get the Paris agreement signed. I mean, good thing they did but it was a fairly wimpy compared to what was and is likely needed.

We need both, less CO2 extracted from fossil fuels and active capture of the CO2 already released.

I was always wondering what is the logic behind that - pump oil from underneath the sea, sell it and buy stock or bonds with the money. Basically trading valuable resources for some paper that may be worth nothing in future.

There are a few areas where I see carbon capture viable:

- Catching CO2 of unavoidable CO2 emitting processes, namely burning trash. In Europe we decided that we do not want landfills anymore, and what cannot be recycled has to be burned. We already start with a higher CO2 concentration, and have energy that is created while burning. Seems like a perfect opportunity for catching CO2.

- Natural processes that catch CO2: Trees, olivine, ...

- Systems for better indoor air with controlled home ventilation systems: I guess you will find people willing to pay for air with a lower CO2 content.

I’m tackling the last one - if anyone’s interested let me know :)

Burn biomass (plants) in a power plant to generate electricity, then store the carbon dioxide in empty gas fields. This is called BECCS, Bioenergy with carbon capture and storage [0].

Unfortunately, carbon capture and storage is not economical (yet). Let's hope it will be soon, with EU CO2 prices already reaching 50 euros / ton this week [1]. If I understand this International Energy Agency report[2] correctly, many forms of carbon capture become economical if these price levels subsist in the EU (and other economic blocs impose similar prices on their industry).

[0] https://en.wikipedia.org/wiki/Bioenergy_with_carbon_capture_... [1] https://www.reuters.com/business/energy/eu-carbon-price-tops... [2] https://www.iea.org/commentaries/is-carbon-capture-too-expen...

Alternative, make charcoal, bury the charcoal, extract whatever useful thing you can from the not-charcol that comes from that process.

Charcoal is pretty much pure carbon and that's what we should be putting into the ground. Putting CO2 into the ground runs into problems because you have to deal with the fact that you are burying a gas (gasses don't like to be contained).

So skip that, and instead focus on burying pure carbon.

This is a good idea, But getting the biomass will be difficult. I dream about large lakes of algae that can be skimmed and then sundried, and cooked in solar ovens to create essentially a solar powered only capture process.

This sort of operation would need a stable cap and trade or carbon tax system to be profitable.

I should also add, I think China or somewhere in the hot parts of Africa would be a a good place for this as it would be a large area operation. Sadly as an Australian we suffer from regulatory capture and a carbon tax won't be back on the cards for some time.

Pretty much the description of all carbon capture. Capturing carbon is inherently difficult.

IMO, barring some breakthrough, biology will be the most efficient mechanism for capture. Millions of years of evolution have made plants and algae pretty good at carbon capture as the carbon levels slowly depleted (until recently).

An appealing benefit of biological carbon capture is the fact that all biology is solar powered. All the non-biological solutions required a pretty hefty energy input from somewhere. I mean, I guess it's nice that you could provide that from solar/wind/or nuclear. But then it's also nice to not require transmission lines for energy input.

The timescale is the issue for humanity.

I'm hoping someone can find, or mix and match an algae in lab that will have the right mix ofproperties to explosively grow.

Providing food stock will be tricky, either through something very efficient like straight sugar or designing the algae to consume anything which could have other upside benefits.

And like all well meaning engineering the real challenge will be making sure the algae that can grow by eating anything doesn't get out of the pond.

Algae are generally autotrophic, meaning they don't need sugar or food, they create sugars from CO2 and light, and they need nutrients like phosphorus and nitrate and other minerals to do so.

But if you provide too much nutrient, too much algae grow, and when they die and decompose they absorb all the oxygen in the water and kill the whole ecosystem. (That's called eutrophication).

Prior art: terra preta[1].

1. https://en.wikipedia.org/wiki/Terra_preta

Here is a untested idea, probably unworkable.

Solar has a problem that consumers tend to need more energy during the night. So the solution is to pipe electricity from somewhere east so everyone's electricity is piped in from say a location east where its still light.

I got the idea when I heard Singapore wants to run a cable to Australia to get solar because they are too small for renewables.

If if could work for those planners it might work elsewhere. People are talking about pumped hydro as batteries, that's good for storage but this is more of a on demand system.

Cool idea, probably unrealistic.

Long distance high voltage DC inter ties are a thing (there is one running from Washington to southern california), but very costly to build.

If you have a truly ridiculous amount of free or almost free photovoltaics somewhere, you could theoretically crack hydrogen from seawater and compress it into tanks, ship it elsewhere (using hydrogen powered ships, hopefully) to be run through giant proton exchange membrane fuel cells. Right now its economics are prohibitively bad. But do the math if the electricity to run the cracking process was far under 1 cent per kWh...

With anything involving seawater, you'll run into the same issues as any desalination plant - where to put the enormous amounts of brine? Potable water is bad enough to electrolyze as there are lots of minerals in it, but salt water is a whole lot worse - and there are massive concerns about the toxicity of brine.

This is more-or-less what the EU will be doing along the northern coast of Africa in the future.

In some cases even more than costly to build, they're an area of cutting edge research.

The public assume that it's just a matter of building a "big wire", but the "big" here has to be so big to be effective that we're actually into the realm of new materials science.

The idea of solar panels in Africa powering homes in Europe is probably unlikely to happen for a long time, and even if it did history has shown us time and again that a distributed network is far more resilient than a centralised one, and so the best solutions look a lot more like putting solar panels on every house.

Think about it for a moment. How far would you need to transmit power for this to be useful without storage, and from what longitudinal spread of locations?

Implicit in my first comment is the transmission losses...

Losses in high-voltage direct current transmission lines are approximately 3-4% per 1000km. Wikipedia has a good article on HVDC btw.

Another perhaps even cooler and not so unrealistic that people are actually working on it, is building the solar farms out in space and beaming the energy down to where it’s needed!

Edit: OK I looked it up again and there are two stages. The one that's having actual work done is beaming energy between two places on earth, but the space one is being "explored".

https://www.economist.com/science-and-technology/2021/02/25/...

And the difference between a space solar farm and a military grade space ray is ?

If you are beaming serous amount of energy toward earth, you better have a good answer to that. Or you will get the visit of very serious people with no sense of humor.

> is ?

is the presence of failsafe mechanisms using lasers around the energy beam so that if any of these lasers are not anymore aligned with its receptors (or if they are interrupted by any obstacle) then the energy beam is immediately cut.

It can even be implemented via optomechanical systems, to be better failure resilient.

That's not the problem.

The problem is 'What assurance does the Department of State have that your space death ray is not going to be deliberately pointed at the next RNC?' and 'What assurances does the Ministry of Foreign Affairs have that it is not going to be deliberately pointed at the May Day Parade?'

You're incredibly unlikely to explain yourself to the satisfaction of both of those groups of people at the same time.

Never mind that this is also a multiple-orders-of-magnitude-impractical means of generating energy.

Not to mention: - What assurances does the Department of Defense have that North Koreas orbital death ray will not cook the white house at any moment.

Well obviously what I said only stands in non-dictatorship.

I don't care to comment on the dictatorship case, that's bad anyway if they launch any satellite at all, we'll never know what's in, so that's not an actionable subject of discussion (except, shoot down all of their spacecrafts).

Democracies have throughout history conducted plenty of assassinations, and started wars of aggression. Some of them have even killed a few hundred thousand people with firebombing and nuclear weapons.

Any country with ASW capabilities would find it prudent to shoot this thing down, because there is no defense from it being used against it - with exactly zero warning.

Yes but again, the distinction is that, in democracies, such evil projects can only be conducted under military secret.

So, any project conducted for the sake of energy production, i.e. in the civilian realm, would have no chance to include these elements of aggression.

Heck, in democracies, even for military projects that are too evil, there are whistleblowers. Especially in high-tech projects, because among scientists there is quite a bit this kind of mindset.

That's just baseless fear from the moment that the system has been designed to be safe.

Plus, you can count on the bazillion scientists working on it to whistleblow any sticks that would have been put in their wheels during the design if the military wanted to middle.

There are only two kinds of projects: secret projects for the military, and civil projects where the design and the safety are pretty much the thing of hundreds engineers not bound by military oaths.

'Trust me, I'm an engineer' doesn't fly with me, and it sure as hell isn't going to fly with another country's government - for the same reason that an engineering firm using nuclear bombs to dig canals isn't going to fly. It's a dual-use technology that can be trivially repurposed for aggression, that cannot be defended against.

You don't seem to understand what I mean.

If the system is designed to be cut in the event that it would be unaligned with its on-ground receptors, through opto-mechanical interrupters, then you cannot use it for an aggression, unless you move the on-ground receptors all the way to your target, but that would be very flagrant and difficult to hide, and every worker at the receptor facility would see it, as well as any other civilian far or near the project.

The only way that such satellite could go wrong is if it actually does not integrate such failsafe mechanisms, and if its real design is hidden, and ill-known to anybody except a handful of military-secret-bound engineers.

If I were to follow your reasoning, then by the same rule any energy plant or even any technological artifact would be incredibly unsafe. But the fact is that we integrate security mechanisms in those, and are mostly satisfied with them, such that we accept to use these technologies.

Of course accidents happen, but the security mechanisms evolve too. Some are so good that they rarely fail anymore, like for example the master cylinder in car brakes (it is an actuator that enhances your effort on the brakes, but if it fails then you end up just pushing raw on the brakes and thus it works anyway, just a little harder).

Of course, this kind of Dyson sphere project will require quite a bit of popular education to convince and explain why its mechanisms make it safe.

This reminds me of the company who developed RNA vaccines because they don't risk to change cells' DNA and they are safer globally, and then they have to explain endlessly to people that no, it's not an evil design, and, no, it does not even include nano-5G-antennas....

> And the difference between a space solar farm and a military grade space ray is ?

And the difference between an airliner and a cruise missile is? And the difference between a rocket and an ICBM is? By your argument, we wouldn't be using those technologies. And yet we do, on a daily basis.

You will notice that ballistic missiles are regulated. Rocket launch are very publicly announced (and tracked).

The known reaction time window of a ballistic missile is ~15 minutes (for russia) to 30m (for the USA) and is already too short, leading to near russian launch at least once that we know of.

The reaction time for any space based weapon is down to minutes to seconds. Putting them into orbit is already a war declaration.

This is not something that will be allowed without heavy international control and multi national regulation.

Given the astronomical amount of energy required for launch, this will almost certainly never even break even on energy.

The idea in those 1970s proposals was to build power satellites with materials mined on the Moon. I guess this sounded more realistic back when the Apollo landings were still within living memory.

OK, so add the cost of building a lunar factory and the breakeven gets worse, not better.

(Most of the 1970s proposals are basically pleas for funding with cool Syd Mead concept art attached, they were never mathematically feasible even in their own era without some other breakthroughs)

The Sun is beaming free energy to Earth already. If it's not enough then humans should become extinct as a species unfit to live in Solar system

There's value in concentrating the energy so that you don't have to cover the entire planet in solar panels.

0.2% of the surface area of land on the planet, when covered in solar panels would produce enough energy to power the entire planet.

The energy in fossil fuels also comes from the sun. Apart from geothermal, it's all sourced from solar, just different ways of storing and extracting that solar energy.

That idea has been around for a long time: https://space.nss.org/colonies-in-space-chapter-3-power-from...

> a location east where its still light.

You've got your directions backwards.

7pm in NYC is 4pm in SF, so you wanted to use solar power to provide evening energy then you generate in the West (SF) to power the East (NY).

And if you want to provide morning energy then they are correct.

In which case it wouldn't be "still light" it would be "already light"

This was an idea pushed by Buckminster Fuller, at the global scale. There seems to be a non profit focused on promoting this [1]. I have no idea if they are credible, and it seems they haven't updated their website [2] in a decade, but it's likely a good starting point to find more resources on the topic.

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

[2] http://www.geni.org/

Solar has a problem that consumers tend to need more energy during the night

That might be true for private households, but it's not true for the average electricity consumer.

For example: https://www.eia.gov/todayinenergy/detail.php?id=42915

The energy required by individual households can be easily stored in a decentralized manner with batteries (e.g. Powerwall).

You can store energy by e.g. pumping water up a hill during the day and using turbine generators at night, or if you don't have a hill heating up water any converting heat back to energy.

Transporting electric power over long distances comes at a cost since wires are resistors unless you're using superconductors which still rrquire low temperatures to work.

Pumped hydro storage is great but very dependant on geography, as without some big height differences it's hard to store enough energy. This makes it infeasible in a lot of locations.

> Cool idea, probably unrealistic.

There's a 3200km(2000 mile) long, 12GW HVDC transmission line somewhere in China that does exactly that.

Its main purpose is to connect regional grids but given the sheer length of the thing the difference in solar time at each end is well over an hour - could have been better, but that would require a different angle.

Technically it was a UHVDC line, " As of 2020, at least thirteen UHVDC transmission lines in China have been completed" ...seems like something the US could invest in with their new infrastructure bill...

"April 2010 announcement for a 2,000 MW, 64 km line between Spain and France is estimated at €700 million. This includes the cost of a tunnel through the Pyrenees"

https://en.m.wikipedia.org/wiki/High-voltage_direct_current

He acknowledges helpfully at the outset that he's not a CCS expert. He's just posing questions by which you could evaluate whether a company is doing anything remarkable, isn't that correct? This isn't a proposal for a CCS company or anything -- more of a guide on how to poke holes in a proposal for such a company.

A side note, I had never heard of Casey Handmer before seeing this. I'm wondering how he appears to be a software developer at JPL but markets himself as some CEO-for-hire on only interesting problems...

Then I suggest you start following his blog :)

Casey's writing is second to none on doing engineering analysis.

A few of my favs:

https://caseyhandmer.wordpress.com/2019/10/29/the-spacex-sta...

https://caseyhandmer.wordpress.com/2020/11/18/supersonic-ele...

I will definitely read some more of his posts.

> CEO-for-hire on only interesting problems

This is a nice (side) job if u can get it. Where do u see any marketing like that in his blog?

As a side note. The blog seems very knowledgable and technical. So good for him.

It's on his Linkedin.

My favorite carbon-capture solution is to breed whales:

https://www.imf.org/external/pubs/ft/fandd/2019/12/natures-s...

Whales act as a nutrient pump in the ocean; beside the 30-tons of carbon they capture and sink over their lifetime in their own biomass, they eat in the deepest parts of the ocean and come back to the surface to breathe, where they release a large amount of nitrate, phosphorus and iron every time they defecate, causing a lot of algal growth.

restoring whales population to their pre-industrial levels could have the same effect as planting several billion trees.

> restoring whales population to their pre-industrial levels could have the same effect as planting several billion trees.

I would like to see the maths on that :D Whales usually don't create their own microclimate or provide a habit for a number of species. They also don't rebuild and support topsoil, can't be harvested for fibres and are not very suitable as building materials.

In other words, trees are more versatile than whales.

Ideally we would have more of both trees and whales as part of a comprehensive approach to climate change mitigation.

Seems like the main competition to carbon capture is reduction in carbon release.

Can it ever compete with finding the thing that currently emits the most fossil carbon and replacing it with something that doesn't do that as much?

Seems like a lot of the carbon capture funding has historically came from Industries that did not want to stop emitting fossil carbon, since that was a key part of their main business, and so needed something that was at least vaguely-plausible as a future solution so they could keep emitting carbon today.

A carbon price, as mentioned in the article, would also pit these two things against each other directly. Generate carbon and pay someone to bury it, or just don't emit it in the first place.

Why not use reduced space-flight costs to lift giant solar reflectors to prevent our poles and ice-caps from being melted? It wouldn't affect insolation at agricultural centers and it would slow warming enough for us to get carbon capture cheaper.

Isn't polar orbit hard?

Global climate is more than just average temperature. Or even "prevent ice caps from melting". It's an insanely complex system that we have only started to understand. There are currents in the oceans and the air, they have complex interdependencies, even with vegetation.

If you change this, you may end up screwing up the climate even more.

The reduction of the albedo effect from the disappearing ice at the poles is a considerable cause of global warming.

Trees? am I not seeing the obvious here? A forest sounds nice. Also algae? Eats tons of carbon, generates most of our o2.

I can't find the reference but a study I read recently said that afforestation could only satisfy 30% of what we need for carbon removal. Here's a result in Wikipedia that says something similar:

> A 2019 study of the global potential for tree restoration showed that there is space for at least 9 million km2 of new forests worldwide, which is a 25% increase from current conditions. This forested area could store up to 205 gigatons of carbon or 25% of the atmosphere's current carbon pool by reducing CO2 in the atmosphere and introducing more O2.

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

And the direct air capture machines capture about a thousand times as much CO2 for the same amount of land.

Died, so https://web.archive.org/web/20210504090615/https://caseyhand...

I have an idea about genetically modifying algae to continuously synthesize and excrete cellulose or similar. In theory would only need sunlight and water to operate, and cellulose could sink to the bottom and collected. Anyone knows if this has been explored?

Algae biofuel has definitely been a thing that people have tried over and over again and it hasn’t happened after a few decades so presumably there is some issue with commercialization.

Wikipedia claims algae has very high water requirements (>600L of water for 1L of fuel) https://en.m.wikipedia.org/wiki/Algae_fuel

> 600L of water for 1L of fuel

Is this actually the problem or is there other factors? A lot more is needed for 1kg of beef or certain crops.

I live in the tropics and water usage is just never an issue and if it was they'd actually store some of what falls from the sky. Truly doubt that water is the real bottleneck here.

edit: From the wiki page

    Among algal fuels' attractive characteristics are that they can be grown with minimal impact on fresh water resources, can be produced using saline and wastewater

"Can be" != commercially viable.

Im proposing a conspiracy theory here, but the basically all of the world's most profitable companies are involved in fossil fuel production. They definitely have an incentive to not want this technology to thrive and their leaders have a lot of influence and money.

The retort to this theory would be that a company with a lot of resources could simply invest in the new technology.

But with the level of lazy corruption in the world it seems possible that these entities might be suppressing the technology somehow.

It doesn't take a huge amount in the way of active suppression: hire a some of the brightest industrial chemists and pay them well to work on your stuff instead of untested, unprofitable algae technology. Other smart people will similarly work on financial derivatives or cost-per-click optimisation instead of money-losing algae.

It's not a conspiracy, it's just capitalism chasing returns.

On the other hand if one of them cracks algae fuel production they get to make an awful lot of future money off all their existing fuel distribution infrastructure. Iirc several of the big oil companies were at least experimenting with it 10 years ago.

Algal systems are ecosystems, and artificial ecosystems are (ironically) prone to collapse. It's like waking up one day and discovering all your houseplants have died, except it's a thousand tonnes of now-dead gunk in your algae bioreactor.

Doesn't matter since you want to dump the gunk somewhere anyways. Just dump it and start over.

Losing entire batches of your product on a regular basis is pretty bad for a commercial product

It is not lost, just a little more dilute than usual, and the gunk is not the end product, just a step in between. It is like prematurely harvesting grass. You get shorter stalks, and some extra work, that is all.

Extra work can make a difference if you are trying to get to competitive with fossil fuels and electricity.

It's not the loss of the product but the process; you have to start it up again. Like accidentally killing your sourdough starter.

Maybe Elon Musk suspects that effective algae biofuel production is a strong candidate for his 100M price, which would benefit SpaceX greatly. Maybe even feasible on Mars, in artificial atmosphere there.

Why wouldn't you use wild type algae, they are already quite efficient in producing biomass?

That is not the same. Then you need nutrients for cell replication as well (amino acids/protein, minerals, vitamins). But if you just collect secreted hydrocarbons from algae you in theory only need sunlight and water, and a little nutrients to maintain the cells. Maybe one issue is that most algae replicate very often, maybe once a day. I used to do bioengineering of an algee (Chlamydomonas) in my Masters

As far as my understanding goes, bio processes using whole organisms/cells like algae/bacteriae/fungi (as opposed to processes using a small set of enzymes or plain chemical processes using catalysts) inevitably come with the disadvantage of heaving a huge overhead. The organism/cell is a complex machinery where there's hundreds of pathways and chemical reactions running that are necessary to just keep the organism alive. Only a fraction of the energy input comes out in the form of the desired molecule. Most is dissipated as heat.

Maybe not the worst analogy would be the comparison between two systems for mining cryptocurrency: A, a specialized chip (ASIC), specifically designed to efficiently run the required algorithms and B, a general purpose PC that has all kinds of peripherals (monitor, keyboard, mouse, hard drive, ...) attached to it, drawing additional power that doesn't benefit the mining. B of course will never beat A in terms of energy efficiency.

So I'd guess if there's a purely chemical/enzymatic process that can do the job, it'll be that, rather than a whole cell/organism.

> In theory would only need sunlight and water to operate ...

Don't forget minerals.

Tangential thought; aren't compressed gas companies who bottle CO2/Nitrogen etc. technically carbon capturing?

Surely they have optimised their industrial processes, which could be repurposed into a large storage unit rather than a cast iron gas bottle?

As the author points out: they are. But you have to look at the CO2 emitted for compressing that gas and creating the containers and so on.

Isn't all that co2 re-released relatively quickly? It gets fizzed and burped right back into the air.

It does, but you could store them underground and capture carbon. Not sure if it scales.

But are they carbon negative? I don't think so

Industrial CO2 is produced by burning natural gas as a byproduct to produce ammonia. DAC is way too expensive.

Have been evaluating CCS/CCU companies as part of https://one.five.ventures/ and the blog post hits most of the major points--especially around purity vs contamination, miracles of scale, etc.

If you are interested in founding something in the space, please reach out!

What ever happened to seeding algae blooms by dumping iron in the ocean? That was getting a lot of press several years back.

You could intercept coal trains... ;)

I literally don't know anything about those processes beside super basic knowledge. But maybe somebody can explain to me why we can't use something like bio-inspired photosynthesis to extract co2? I bet plants are not co2 throughput optimised. The technology may not be there, but would it be feasible in theory without using too much energy?

plants are nifty little machines, which - while their efficeny might not be optimal - also produce all their parts. Go look at one of the papers doing Re-based CO2-dissociation and shop for the chemicals!

I don't know of any technology where you get both the desired effect as well as an in-built mechanism for cloning the machine using locally sourced materials, often without human intervention.

Would planting a lot of trees and them putting them into flooded mines work?

Not sure why he talks about the financial side. CC on scale will be a government driven operation, paid via taxing the population and it will cost whatever it costs, like many other things.

Of course costs matter. If it costs 100x more to capture the carbon than building higher levees, we will build higher levees and (hopefuly) use the leftover money to evacuate people in very low and/or poor countries to higher ground.

How about producing less CO2 in the first place and planting trees to reduce CO2 concentration

Planting trees uses too much land that is increasingly needed to support the growing population. Not an option.

Some numbers:

The US Forest Service estimates that 1 acre of forest stores about 80 tons of carbon. You could store about 180 billion tons of carbon onto that area if it were all a forest.

CO2 makes up about 3 trillion tons of the atmosphere. ~27% of it is carbon, therefore there is roughly 800 billion tons of carbon in the atmosphere.

It seems plausible that if we somehow planted a forest on the entire Sahara desert, that we could reduce the amount of carbon in the atmosphere by a significant amount.

I hope I didn't make any errors in my calculations.

The reduced albedo effect from the no longer radiant Sahara would cause a significant amount of heat absorption. While it would remove CO2, for a while, the increased heat would be enough to almost offset the entire benefit from the project.

This is not something I considered at all! If this impact is so large, then would having more clouds significantly help with warming?

what about phytoplankton?

Very sobering article. But startups are not about building a carbon concentration machine, they need money concentration machine. Thermodynamics don't apply directly here.

TL,DR: What are the problems to solve for efficient CC?

Answer that's missing in the article:

CO2 is one of the stablest elements in the atmosphere. Removing it will require humongous amounts of energy (as a rule of the thumb, more energy than the energy-producing process that generated this CO2 in the first place). Therefore CC at scale is probably a pipe dream and will remain so, because thermodynamics.

Most of the energy used in CO2 capture through amine absorption is in the form of heat. Luckily, most processes where point-source CCS could be used produce waste gas streams at very high temperatures which can significantly reduce the additional energy that needs to be added.

what about trees, the cheapest and most efficient "carbon capture machine".

with that prize money one can plant a whole lot of forests

https://www.goodnewsnetwork.org/how-many-trees-to-plant-to-s...

https://edenprojects.org/

Has the author heard of photosynthesis?

He is making valid point that we would need more energy to capture but we have lot of energy we could use in daytime near equator. Fossil fuel are burnt just because they are easy to work with and could produce energy all the time, but we have lot of solar energy that is wasted.

A plant is basically a self-healing, self-replicating CO2-capturing machine running off solar power and some chemicals.

They also need massive amounts of water when planted at scale and die after anything between 1-100 years (some hardwood trees live longer but capture carbon relatively slowly compared to faster growing plants), after which they release the carbon back into the ecosystem. Energy efficiency of photosynthesis is also really low.

Just planting a lot of plants and expecting they will efficiently capture a lot of carbon out of the air is going to lead to disappointment.

We could create mechanical replacement which works with sea water and doesn't require us to wait for a decade to get result and likely more optimized for just one task.

Aren't technological plant replacements usually just called solar panels?

I was talking about carbon capture using sunlight.

That's very shallow dismissal. Yes, it's true "just planting a lot of plants" will lead to disappointment. But it's the same as with "just build lots of solar panels/windmills" without any systematic thinking.

Natural and sustainably managed biomes don't require irrigation. I know, there are deserts where much biomass won't ever naturally grow, but no solution is suitable everywhere.

Trees can and do last longer than 100 years, and even after death they don't puff release co2 immediately. When left undisturbed, large part of carbon is left fixed in the soil.

> A plant is basically a self-healing, self-replicating CO2-capturing machine running off solar power and some chemicals.

Not in itself. When the plant dies, it rots and all the carbon goes back to the atmosphere by the action of fungi and bacteria.

Plants can function as the zeroth step in a carbon capture pipeline. The actual capture happens when the plant dies and you bury (or otherwise process) its tissue somewhere so that the carbon cannot go back to the biosphere.

Just growing plants and letting them die is purely carbon neutral.

> Just growing plants and letting them die is purely carbon neutral.

Actually, no. Depending on the plants and circumstances, it can be carbon-(equivalent)-positive because rotting plant material exudes methane, which has a far higher global warming potential than CO₂. So even with simple plant agriculture you can harm the climate, e.g. wet rice production.

OTOH, growing plants, turning them into charcoal and sequestering that can be carbon-negative.

It's carbon-negative even if you don't count the buried carbon due to it being a powerful fertilizing agent.

I don't understand your remark. The plants that you are going to fertilize are part of a carbon neutral cycle anyway. It doesn't really matter if there is a big or small amount of them. The buried stuff is going to rot after a few years and release the carbon back.

I think the idea is to bury it to "geological" depths, forever isolated to the biosphere.

In the last century, we have burned millions of years worth of plant-based carbon sequestration. This was carbon that had been out of the biosphere for millions of years. Now our goal is to remove this carbon out of the biosphere again. I'm skeptical that this can be at all achieved by purely biological means. But burying dead plants a few meters deep, readily accessible to rot, is not likely to make any difference. Otherwise, we are going back to pre-cambrian CO2 levels, which were much higher than today.

Read up on black soil.

The author does specifically list "planting trees", so presumably yes?

> If we’re going to capture 10 GT of CO2 a year by planting trees, how much water will we need to irrigate them?

Okay, so we build out massive renewable capacity. Wouldn't that energy be better used directly, than to run inefficient carbon capture equipment while other people keep pumping the stuff into the atmosphere? Wouldn't that system basically be using the atmosphere as a really crappy battery, where the efficiency is shit and we still have to keep digging up oil to make it work? Yeah, renewables are peaky, but surely there are better ways of solving that problem?

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