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Published on January 19th, 2016 | by Michael Barnard

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Carbon Capture Is Expensive Because Physics

January 19th, 2016 by  

Carbon capture and sequestration is expensive because it has three components, each with its own expensive challenges: capture, distribution, and sequestration. The mass of CO2 produced is 2-3 times the mass of coal or methane* burned and is more challenging per unit to ship than coal, so the cost of capture, distribution and sequestration is typically a multiple of the cost of doing the same with the coal or methane.

How expensive is it?

Screen Shot 2016-01-16 at 1.28.48 PMAccording to an organization which promotes carbon capture and sequestration, it will cost $120-$140 per ton of CO2. This will add from $168 to $196 to the cost of a MWh of coal generation. That’s 16.8 to 19.6 cents per KWh, which puts existing coal plants impossibly deep into unprofitable territory. Methane generation plants emit less CO2 per MWH, so would see 9.5 to about 11 cents per KWH added to their base cost, typically in the 5 to 7 cent range. Coal generation at 20 to 25 cents per KWH wholesale and methane generation at 15 to 18 cents per KWH wholesale wouldn’t be purchased by any utility.

 


How is Carbon Captured?

There are two general approaches to carbon capture, each of which have different challenges.

Carbon capture at source of emissions diverts exhaust emissions from coal and gas generation plants through a series of catalysts, sorbents and other technologies.

Coal plants in developed countries already have scrubbers for sulphur and filters for particulate matters. Retrofitting another step onto these two is another bolt-on.

Coal and methane generation flues originally were very simply designed, with the heat of the emissions overcoming gravity so that the fumes flowed upward and out. With each addition of filtration and scrubbing, that ability to void emissions with waste heat is reduced. Now electricity is used to operate fans that push the emissions through the various filtration points. That costs money, or rather is consider as auxiliary power load on the generation station, and every point of auxiliary power is money that they aren’t making.

images-11Capturing CO2 typically uses sorbents, porous ceramic filters which capture the CO2 and let everything else through. They expect gases within a certain temperature range and set of components to operate effectively. Achieving these conditions may require cooling the emissions further or other processing. Both of these add costs.

Sorbents are effectively ceramic nano filters. Air must be forced through them. This requires larger fans and more electricity, once again increasing costs.

fotw519More CO2 is emitted than coal or gas is burned. CO2 is formed by a chemical reaction of the carbon in the fossil fuel with oxygen from the atmosphere. Oxygen has an atomic mass a hair under 16. Carbon has an atomic mass a hair over 12. Adding two heavier atoms to one lighter atom means that about 3.67 times the weight of carbon in the coal is emitted as CO2. Coal is about 51% carbon so the CO2 weights about 1.87 times the weight of coal. Burning methane (CH4) produces about 2.75 times the weight of CO2. What this means is that the mechanism for capturing and processing the CO2 is going to be potentially larger in scale than the mechanism for burning the coal and gas in the first place. The energy required to capture the very large amount of CO2 is non-trivial.

Typically, sorbents are dropped into a hot liquid bath to release the captured CO2. Heating the water up requires energy, and heating water takes a lot of energy. There’s lots of waste heat in coal and gas plants because most of the energy from burning coal and gas is wasted as heat, so this isn’t as big a problem, but that heat has to be directed to the correct place in the right amounts. Once again, more duct work, more processing, more fans and more controls. More expense.

CO2 when captured is a gas. It’s very diffuse. In order to store it, it must be compressed or liquified. Compressing and liquifying via cooling are both highly energy-consuming processes. More expense.

liquid-CO2-Storage-tanks4-zCO2 must typically be stored onsite in preparation for shipping. Given that the weight of the CO2 is 1.87 time the weight of coal and that CO2 must be stored in compressed or liquified form, this requires very large pressure vessels or very large pressure and insulated vessels. By comparison, coal can be piled on the ground before use. This means that the effluent requires a much greater expense for storage and handing than the feedstock.


 

Air carbon capture ignores the source of carbon emissions, and like a plant works off of the ambient CO2 in the atmosphere, right now just over 400 parts per million. Air carbon capture avoids some of the issues, but adds others.

  • By using air, concerns about temperature and contaminants causing inefficiencies in the sorbent are reduced substantially.
  • 400 ppm is a much lower concentration of CO2 in the atmosphere than is found in coal or gas plant emissions. That means that a great deal more air must be forced through the sorbents and there is no ‘free’ auxiliary power to do this with, but must be purchased.
  • Sorbents must still be put into heated liquid in order to release the CO2 and heating water is very expensive. That’s why Global Thermostat’s solution is to use waste industrial heat at sites which require CO2 as a feedstock, allowing the waste industrial heat to overcome one expense, and avoiding the distribution expense (to be explained later).
  • CO2 must still be compressed or liquified.
  • CO2 must still be stored in preparation for distribution or use.

How is CO2 Distributed?

As pointed out, CO2 produced by burning coal or methane is 1.87 times the mass of coal, 2.75 times the mass of methane, is a gas or a liquid and must be kept compressed or very cold. It is much more like methane than it is like coal. Distribution of it is much more challenging than coal.

While coal can be run in open hopper train cars, CO2 distributed by train requires pressure containers or pressure containers that are also maintained at a very low temperature. The total number of train cars required is much higher than the number of train cars which would deliver the coal, and this would be a substantially higher expense as a result. Coal is a cheap commodity and getting it from point A to point B is a large portion of its expense already, which is why many coal generation plants are built at coal mines.

When CO2 is distributed by pipeline, the pipeline has to deal with 2.75 times the mass of CO2 as of gas entering the facility, effectively requiring close to three times the infrastructure to remove the waste as the feedstock. Regardless of whether a coal or gas plant is considered, all of that pipeline must be built.

6a00d83455737669e20120a56ff262970c-640wiVery few CO2 pipelines exist in any country. Several do in the USA. They run mostly from geological formations which trapped CO2 over millions of years to enhanced oil recovery sites for the most part. More on that later. Extensive increases in capturing CO2 at source or from the air would require a very large network of new pipelines which would need to be constructed at great infrastructure expense.

Both trains and pipelines are businesses. They make money by moving commodities and goods through their networks from producers to consumers. Moving CO2 will cost more money than moving the coal or gas does, effectively doubling or tripling distribution costs for every coal and gas plant.

All of the above is why many places that require CO2 as an industrial feedstock use CO2 production facilities onsite instead of purchasing it. They burn gas or oil themselves to create the CO2 so that they don’t have to pay two to three times the cost to have it shipped to them.

CO2 is a commodity which is worth $17-$50 a ton. Coal ranges from about $40 to $140, depending on several factors although it has been in decline for a while. Methane is in the $2-$5 per million BTU range with about 35,000 BTU per cubic meter. Suffice it to say, coal and gas are worth more than CO2 as commodities, and the ratio of the expense of distribution to value of the commodity is very different, especially when you consider two to three times the mass needing to be distributed.

Coal and gas generation plants are placed close to population centers or coal beds, not close to places which require CO2 or where CO2 can be sequestered. Distribution is a very expensive component of the cost of CCS.


How is CO2 sequestered or used?

Especially if coal and methane continue to be burned for electricity, it is not enough to capture CO2, it must be stored securely for periods closer to how long the coal and methane were underground than to human lifetimes. The containment storage can’t leak significantly and must work passively. As CO2 is a gas in the range of temperatures in the atmosphere and below the surface of the earth, it by definition likes to leak.

By far the biggest consumption point for CO2 is enhanced oil recovery fields. CO2 is acidic. Pumping it into played out oil fields makes the remaining sludge flow more smoothly and increases pressures underground. This makes the oil flow toward the other end of the field where it can be pumped out.

health-safety-and-environment-aspects-of-carbon-dioxide-sequestration-by-dr-g-p-karmakar-professor-in-petroleum-engineering-school-of-petroleum-technology-pandit-deendayal-petroleum-university-12-638In theory, the CO2 used in enhanced oil recovery remains underground, but in practice, it is being pumped into formations with dozens or even thousands of natural and man-created holes in the form of oil wells and natural faults. Enhanced oil recovery is not a sequestration technique, but a technique designed to get more carbon-based fuel out of the ground to be burned.

Enhanced oil recovery cannot be seriously considered as a sequestration technique if the CO2 merely leaks to the surface again and more carbon is extracted from fossil fuel beds and released into the atmosphere through burning. Significant amounts of effort have to be performed to keep the CO2 from leaking, and there is little value to the EOR operators in doing so, so it typically doesn’t get done.

Comparatively small amounts of CO2 are used by other industrial processes such as soft drinks, industrial scale greenhouses, some forms of cement, etc. There is no substantial market for CO2 which is not being met today, hence the reason why the commodity is cheap. About three-quarters of industrial CO2 is captured from underground concentrations of CO2, effectively like methane deposits. This CO2 is cheap compared to sequestering it after it is created, so captured CO2 has a higher cost base than mined CO2 and will not be competitive with it, especially without a carbon tax. As was already pointed out, the large majority of pipelines for CO2 are from mining points to major enhanced oil recovery sites, not from places it is created due to generation to industrial consumers.

Enhanced oil recovery used only 48 million metric tons of CO2 in 2008 in the USA, which would be the CO2 emissions from only 13 coal generation plants. The other consumers of CO2 are much smaller. In 2013, there were over 500 coal generation plants and over 1,700 methane generation plants in the USA alone. Capturing CO2 from all forms of coal and methane generation would swamp what market exists for CO2, collapsing its value and making it even less economically viable.

Other forms of sequestration have no fiscal value at all, but merely inject the CO2 into underground structures where it remains as a gas or bonds with other minerals underground to become calcium carbonate, a stable mineral. Injecting the CO2 requires large facilities, drilling, capping, pumping, monitoring etc. There is no revenue gained to offset this, so very little of this is done except as ‘pilots’, ‘test facilities’ and the like. While it has interesting challenges from an engineering perspective, it’s hard to imagine anyone with a good STEM background directly involved with it taking it seriously as a solution.


What does this all add up to?

Carbon capture and sequestration will never be economically viable compared to alternatives. The physical reality of the scale of CO2 production from generation requires a distribution infrastructure two to three times the scale of the existing fossil fuel distribution infrastructure and would result in electricity at four to five times the cost. Meanwhile, wind and solar generation are already directly cost competitive with and actually cheaper in many places than fossil fuel generation. This trend is clear. Fossil fuel generation without carbon capture and sequestration is trending to be or already is more expensive than renewable generation which emits no CO2 during operation and is getting cheaper.

Fossil fuels are nature’s form of carbon sequestration, and nature took millions of years of free and slow processes to do so. It’s not a rational choice for humanity to dig up the sequestered carbon, recapture it and resequester it at great expense when there are alternatives. Leaving the carbon that geological processes sequestered where it is is the rational choice.


* Natural gas is 89.5% to 92.5% methane which is a much more potent greenhouse gas than CO2 in the short term. When burned, by far the dominant use for it, it emits CO2 in significant amounts. Extraction, storage and distribution all have leaks from small to disastrous in scale and when used as intended it creates CO2. Calling it methane more accurately labels it and allows lay people to understand the implications of its use. Like ‘clean coal’, ‘natural gas’ has PR connotations which are undeserved.

 
 
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About the Author

For the past several years Michael has been analyzing and publishing reports and articles on decarbonization technologies, business models and policies. His pieces on electrical generation transformation and electrification of transportation have been published in CleanTechnica, Newsweek, Slate, Forbes, Huffington Post, Quartz, RenewEconomy, RenewablesInternational and Gizmag, as well as included in textbooks. Third-party articles on his analyses and interviews with Mike have been published in dozens of news sites globally and have reached #1 on Reddit Science. Much of his work originates on Quora.com, where Mike has been a Top Writer annually since 2012. He also has published a climate-fiction novel, Guangzhou Future Tense.



  • George McKee

    Remember where that oil and coal originally came from 400 million years ago? It’s sequestered biomass. We need to duplicate that process rather than just pushing the CO2 underground. CO2-eating algae can be bioengineered to be more efficient than ever, and with solar drying can provide a carbon-negative sink that can even spare a few BTUs to power its farms’ pumps and other energy-consuming processes.

    • Bob_Wallace

      It does not make sense to continue to extract carbon from below the surface and burn it as fuel even if we give the carbon a second life by feeding it to algae.

      That would slow CO2 emissions but not eliminate them.

  • David Allen

    What hasn’t been mentioned yet is the cost of energy storage required to support renewable generation, assuming that it is necessary to keep the lights on 24/7. Wind and solar are intermittent. Fossil power, with or without CCS, can generate flexibly as and when needed. So, the cost comparison does not compare like with like. Renewables may be cheap, but renewables plus storage will be a lot more expensive.

    None of this contradicts the conclusion that CCS is very expensive and won’t be economic on a large scale without a very high carbon price. However, it can more easily become economic for the (fairly large) niche application of providing power for when the wind doesn’t blow and the sun doesn’t shine.

    • Bob_Wallace

      EOS Energy Systems is selling zinc-acid batteries for $160/kWh. Cycled once a day that works out to $0.05/kWh. Panasonic/Tesla are heading toward $100/kWh. The Swiss calculate that they can build new pump-up hydro for $0.05/kWh.

      FF w/o CCS can only be tolerated in very small amounts. So it comes down to the cost of FF w/CCS vs. stored wind/solar.

      The other thing to throw into the mix is biomass/gas for deep backup, those few times when wind and solar are really low over a very large area. A large enough area to make shipping power in from another area too expensive.
      We’re years away from needing to fill in for wind and solar, there’s lots of NG and hydro to curtail when wind and solar are providing. Watching what is happening with batteries it’s likely that stored wind and solar plus battery storage are going to be the choices for two or three day fill in. Sometime down the road we’ll have to make the >3 day decision and who knows what we’ll have available by then.

      • David Allen

        5 cents per kWh is about the same as the figure given in the original article as the base cost of methane generation, 5-7 cents per kWh, and a bit less than the estimated costs of CCS, 9-11 cents for methane and 17-19 for coal. It is a significant extra cost, even if the favourable figures you quote prove fully accurate.

        The cost of methane generation with CCS comes out at 16-18 cents. So, according to these figures, renewables excluding storage must cost less than about 12 cents, if they are to be competitive with that. This does sound quite feasible, but it doesn’t allow for energy losses in storage, or for the need for excess storage capacities to deal with weather uncertainties and different storage timescales, or for the various risk factors and uncertainties (which, mind you, are also pretty high for CCS, of course).

        I can believe that renewables plus storage might well beat fossil plus CCS in terms of economics, but it won’t be by a street. A prudent generating company would do what prudent companies usually do, which is to back all the horses in the race.

        • Bob_Wallace

          “Methane generation plants emit less CO2 per MWH, so would see 9.5 to about 11 cents per KWH added to their base cost, typically in the 5 to 7 cent range. ”

          That makes NG w/CCS from 14.5 cents to 18 cents.

          ” renewables excluding storage must cost less than about 12 cents,”

          Wind = $0.0235/kWh average 2014 PPA (subsidized).

          DOE “2014 Wind Technologies Market Report”

          http://energy.gov/eere/wind/downloads/2014-wind-technologies-market-report

          Solar = $0.05/kWh PPAs (subsidized) being signed in the US Southwest. Working backwards through a LCOE calculation extrapolates a cost of about $0.02 higher for the less sunny Northeast.

          Lawrence Berkeley National Laboratory entitled “Utility-Scale Solar 2013: An Empirical Analysis of Project Cost, Performance, and Pricing Trends in the United States”

          http://emp.lbl.gov/sites/all/files/utility-scale-solar-2013-report.pdf

          PPA prices for wind and solar are lowered about 1.5 cents by PTC (Production Tax Credits). Both wind and solar are eligible for 2.3 cent/kWh tax credits for each kWh produced during their first ten years of operation. Half of 2.3 is 1.15, but getting ones money early has value. That means that the non-subsidized costs of wind are a bit under 4 cents and solar is running 6.5 to 8.5 cents/kWh.

          http://energy.gov/savings/renewable-electricity-production-tax-credit-ptc

          Those are 2014 prices. Wind was almost certainly be lower in 2015 and the installed solar price of utility solar was down 16.9% Q3 2014 to Q3 2015. That’s enough to drop solar to the 5.5 to 7.2 cents per kWh range.

          We’re moving to wind at 3 cents or less and solar probably averaging under 4 cents. That leaves at least a minimum of 10 cents for storage.

          And remember, those gas prices are for CCNG run at full capacity, not gas peakers which are the correct comparison to stored wind/solar. Peaker electricity is over 15c/kWh. Add on CCS.

          Or if you want to compare CCNG/CCS to an equal amount of wind/solar/storage then you have to use 80% wind/solar and 20% stored wind/solar. (Some number in the 20% area.) 80% at 4c and 20% at 10c works out to 5.2c/kWh.

    • Energy storage is likely to be under 20% of total generation capacity and is an end game issue, not a near game issue.

      Virtually every energy storage study has been narrowly constrained and ignores empirically observable trends and options:
      – There is virtually no storage today because it is cheaper to overbuild capacity than to build storage. Only nuclear runs at anywhere near its theoretical maximum capacity factor because it’s uneconomic if it doesn’t. Wind and solar will be overbuilt because they are already cheaper than almost everything else and will be cheaper than anything else and their output will be turned off when not needed.
      – Large scale grid interconnections allow electricity to go from where it is generated to where it is needed with relatively small losses and lower losses as HVDC corridors are built. This is a very low cost per MWH compared to storage and is being done on every continent. Manitoba, Quebec and Norway are all continental passive batteries and are specifically tuning their business models to provide passive storage at reasonable rates.
      – The fastest form of backup that exists on the grid outside of chemical storage are wind farms which are operating below peak. Operators are already slightly feathering wind farms so that they can provide peak demand as required. Adjust pitch and there’s more power extremely quickly. Once again, overbuilt generation will be sub optimized and take care of most perceived needs.
      – Every GWH of electricity produced by renewables pretty much knocks a GWH of fossil fuels off the grid. That’s the heavy lifting. Storage is cleaning up around the edges in the end game.

      Storage is a growing space, but it’s vastly overstated as a need or concern.

      • David Allen

        Yes, insofar as overbuild is cheaper than storage (despite being less than 100% reliable without a very high margin of overbuild), overbuild will be adopted in place of storage. However, that will not eliminate the additional costs. At best it will somewhat reduce them.

        At present, the economics of overbuild are a bit difficult to read. Overbuild has happened in the sense that expensive renewables have been built and have displaced cheaper fossil plant already in place. The costs of this have been dumped on those evil fossil generators without much remorse. Now, as renewables become cheaper and potentially competitive without subsidy (and more certainly competitive with abated fossil power), we will gradually see renewable plant more often turned off, with negative effects on its own economics. A rational generating company will want to hedge against the risks involved by various means – by seeking to continue burning unabated fossil, by pursuing CCS, even by diversifying into nuclear. To sum up – I like the story you are telling, it’s an important story, I’m just not sure it’s the complete story!

        • Well, if reliability is your concern, you should rest easy. The most reliable grids in the world are the ones with the highest degree of renewables on them. And there’s no storage on those grids to speak of.

          Germany averages 15 minutes of grid disruption a year and frequently exceeds 100% of demand with renewables.

          France averages over an hour of grid disruption a year with 75% nuclear.

          Poland averages over four hours of grid disruption a year with 80%-90% coal generation.

          Reliability is like storage, a scare tactic by traditional generators. It’s relatively meaningless.

          http://spectrum.ieee.org/energywise/energy/the-smarter-grid/germanys-superstable-solarsoaked-grid

          http://business.financialpost.com/news/energy/wind-solar-get-reliable-as-power-grids-fine-tune-forecasts?__lsa=2275-b02f

          Active storage requirements are likely under 20% of generation capacity and are an end game, not a beginning game. Essential to finalize decarbonization, yes, but not something that’s particularly troublesome.

          • David Allen

            Hmm. Your Spectrum reference attributes Germany’s high reliability to underground power lines, not renewables. It may also be related to a high level of overbuild and hence high costs. Your second reference notes that a massive expansion of the German grid will be needed to cope with renewables as their nuclear plants are phased out, presumably eliminating a temporarily very high level of overbuild.

            I do take the point that the supposedly better reliability of fossil plant can be, and is, seriously over-sold. However, simply to dismiss all concerns about reliability as “meaningless” is surely far too facile.

          • Relatively meaningless. It’s a scare tactic and reliability is easily dealt with. If you’d prefer a different example, how about Denmark, which regularly exceeds 100% of demand from wind energy alone, topped 40% of total demand from wind alone in 2015 and has no storage to speak of. It’s pretty much as reliable as Germany. Empirically grid reliability appears to increase with increased penetration of renewables.

            http://www.renewablesinternational.net/overview-of-grid-reliability-in-eu/150/537/75716/

            Yes adaptation of grid management practices and technologies is required, but in practice, more renewables correlates to more robust grids, not the opposite.

            Texas is a counter-example because they are mostly not connected to even other states. Their isolation makes them weak, not renewables.

          • David Allen

            OK, here is what your latest reference actually says:

            “The share of distributed renewables is therefore probably not the main
            reason for high levels of grid reliability – underground cables are.”

            “Intermittent renewables have not yet reached a penetration level that
            has detrimentally impacted grid reliability in any country in the EU.”

            That seems fair.

        • Bob_Wallace

          ” A rational generating company will want to hedge against the risks involved by various means – by seeking to continue burning unabated fossil, by pursuing CCS, even by diversifying into nuclear. ”

          Coal plants with CCs and nuclear are not answers for wind/solar fill-in. They aren’t readily dispatchable and since they already are expensive using them on a limited basis makes them even more expensive.

          The costs of coal and nuclear is mostly about capital and financing costs, fuel costs are minimal. The cost of their produced electricity rise rapidly as their annual output is curtailed. There’s little savings to be had from reducing fuel use, especially with nuclear.

          Natural gas with CCS has a lower installed installed cost and could be useful as fill-in but it will have to be compared to pump-up hydro, flow batteries and biofuels.

  • Tom Capon

    Has anyone considered that sequestering large amounts of carbon dioxide also means removing large quantities of oxygen from the atmosphere? If only we could convert it to graphite before burying it in the ground.

  • neroden

    Carbon capture will only be done *after* we stop burning fossil fuels — we’ll need to do it to pull excess carbon out of the air. The profitable ways to do it which I know of:
    (1) carbon-negative concrete (two formulations exist so far)
    (2) plant growth (this should be obvious) with biochar sinking

    Both of these are really marginal compared to the effects of fossil fuel burning. We have to stop burning fossil fuels first.

  • Greg Cragg

    I do not agree, my two ways to capture any cites co2 and sequester will capture the most co2 ever, with uses, or sequester, without leaks, with a way to pay for the process. I have a way to sequester above ground, that offers over one million years of safe storage, for co2, Nuclear Waste, and Hazardous Chemicals, all proven technology. Doing nothing but talk is not an option, I have action-who is interested?

  • Matthew Uddenberg

    I feel like most people who have dived into the CCS problem have found that, as it is currently envisioned, there is very little hope of it becoming economical. Yes EOR is a potentially economic use, but just storing it underground has many problems. These include, cost, leakage, earthquakes, groundwater contamination among a host of other problems. I think the key here is that the way it currently has been envisioned won’t work, however there are other options: biomass, cement created with atmospheric CO2, as a feed stock for plastics etc. Carbon capture is not a failed concept. However, storing vast amounts of gaseous CO2 underground will likely not work.

    • The challenge is that this does not eliminate the serious challenges of sequestration costs, distribution costs or the collapse of commodity costs if the market is flooded.

      One silver lining is that if the commodity market for CO2 did collapse due to widespread capture, then induced demand would create some new markets for it. Caldera’s CO2 sequestering cement is great and would be more competitive if one of their feedstock was much cheaper. But it’s still a drop in the bucket compared to scale.

      The solutions for sequestration don’t scale to the scale of emissions, not even close. That doesn’t make them useless, just expensive and niche.

      • just_jim

        I am mostly in agreement with you. Sequester is no substitute for going to a carbon neutral economy. My one area of disagreement is that once we get to carbon neutral, our CO2 level may still be high enough that we will be faced with warming that will lead to dangerous conditions.

        Then, in my opinion we will need to consider actions like CO2 sequestering cement, bio-char, and anything else that can cost-effectively reduce existing CO2 levels.

        I hope that I am wrong, and we can keep global warming to non-dangerous levels without sequester. However, we need to keep the option available.

      • neroden

        The magnesium cement process (Novacem/Caldera) is one carbon-negative cement process; the iron cement process (Ferrock) is another.

  • Ronald Brakels

    Provided no one sees me do it, right now I could sequester carbon for probably under $70 US a tonne biologically. Now I don’t mean with my own personal biological processes, as prodigious as they are, rather I refer to dumping biomass in deep ocean waters away from areas of ocean upwelling. Or alternatively, in areas of sedimentation. Cold water lakes would be another option, but you know, I’ve never found one around here.

    Now this can’t sop up emissions from coal or large scale natural gas use. It’s just not possible to do it on a large enough scale. And it doen’t pay for itself anyway as it’s a lot cheaper to eliminate coal and large scale natural gas use. But if there are places where it turns out to be very expensive to eliminate fossil fuel use, for example perhaps aviation, then it could be cost effective to use biological carbon capture and sequestration, at least until we come up with something better.

    So the ability to capture and sequester carbon using biomass should put an upper limit on the carbon price required for the world to go carbon neutral. Hopefully it will be less than $70 US a tonne.

    • For aviation, there are already synthetic biofuels which duplicate jet fuel. They are more expensive, but they’ve been approved and certified for several years, and used in tests by airlines. Similarly, biodiesel has been around for decades for freight hauling ships and the like.

      Building carbon neutral fuel for transport where electrification isn’t viable is less expensive than attempting to sequester carbon from carbon sinks laid down by biological processes over millions of years in my opinion, but I haven’t done the math to prove that to my satisfaction. At least not yet.

      There are also the concerns of the Law of Unintended Consequences. At sufficient scale to be at all meaningful, what will that much biomass do in the ocean depths? How will it change the ecosystems? Will it change salinity or other factors? Hard to know for sure. Perhaps that’s why you say “as long as no one sees me do it”. 😉

      I’m pretty much with the folks who raise concerns about geoengineering concerns. Let’s stop screwing things up and let geological and biological systems recover rather than try to paper over the screw ups.

      http://www.scientificamerican.com/article/geoengineering-is-not-a-solution-to-climate-change/

      • Mike Gitarev

        Not sure about salinity, but oceans goes more acidic.

      • Ronald Brakels

        It is certainly possible to grow plants and then convert them into biofuels for aviation. Or those plants could simply be dumped in the oceans and then $26 a barrel oil, or perhaps $5 a barrel oil after we electrify ground transport, could be used for aviation using existing infrastructure. I think there is a good chance the second option will be cheaper, at least in the short to medium term.

        But regardless of how easy or difficult it is to remove fossil fuel use from various applications, if a carbon price is set high enough for the world to go carbon neutral then some forms of atmospheric CO2 capture and sequestration will be used as those involved in activities where removing emissions is more problematic will purchase credits from those practicing the cheaper forms of atmospheric CO2 removal and sequestration. It’s not something that can really be stopped unless we ditch carbon pricing and go for command and control measures instead. I don’t recommend those.

        Of course, if we only want to cut greenhouse gas emissions by say 90% then atmospheric removal and sequestration of CO2 may never be done on an appreciable scale.

        As for unintended consequences, any atmospheric carbon removal and sequestration is only worthwhile if the costs and risks are less than the costs and risks of leaving the carbon in the atmosphere. To undertake any form of atmospheric carbon removal and sequestration where the costs and risks are expected to be greater than leaving it in the atmosphere would be unwise.

    • JamesWimberley

      The $64 trillion dollar question is whether carbon neutrality (at best by 2050) and a CO2 concentration of 450 ppm will correspond to a liveable planet. If James Hansen is right – and has a track record of being right on climate science, even if he’s clueless on technology – then we wilt have no choice but to sequester by the hundred gigatonnes. The research for the insurance policy should start now. Fund it by shutting down the nuclear power research boondoggle.

      • Ronald Brakels

        I am optimistic about us avoiding a 450 peak. However, full disclosure, I am a lunatic. If you asked me my reasons for optimism my explanation would probably contain far too much fairy dust and unicorns for you to find it satisfying. But regardless of what peak is actually reached, to limit damage we clearly need to cut emissions as fast as realistically possible. And realistically speaking, that is actually quite fast given the low and declining cost of renewable energy and the declining cost of electric transport. If we cut emissions by 90% or more our battered carbon sinks will reduce CO2 levels in the atmosphere by a considerable amount before they start to approach equilbrium. Now it could definitely be a very sensible idea to start removing gigatonnes of carbon from the atmosphere at this point to further limit damage and increase our safety margin for avoiding disaster, but I see that as something to worry about in the future. Future people can decide what is the best course of action to take. Our job is to make sure there are future people to make those choices. If Australian stingless bees haven’t stabbed me to death with the little knives they carry and I’m still alive in the future, I’ll worry about it then.

  • Takeshi

    This is perhaps a tangent, but I still believe that atmospheric carbon sequestration on an industrial scale will be required to stabilize the ecosystem and prevent runaway climate change.

    We’ve already added too much carbon to the sky. Now we need to stop burning it, first and foremost, and then set out figuring how to best remove it and store it for millennia. Fortunately there is some work being done in this regard. Biochar and re-forestation are my personal top contenders since they require little infrastructure, but there are some moonshot technologies on the table as well.

    Recent work in materials science has shown that it is possible to pull CO2 from the air and cheaply make carbon nanofibers, which are incredibly strong and light. The process can be run on solar panels and wind if we like; intermittency is not an issue. It gives me hope, albeit a glimmer.

    • Ross

      It will definitely have to be on industrial scale.

      In the Keeling curve there’s a seasonal swing up and down of about 4ppm. The long term trend upwards is a few ppm per year.

      To keep it simple assume that we succeed in transitioning to a 100% carbon neutral energy system (burning no fossil fuels) well before the turn of the century.

      We know the huge scale of the drivers of the rates of change in the Keeling curve.

      After the 1st order solution of ending FF emissions has been achieved we’ll have to continue reducing the cost of energy so that we can also power the sequestration of atmospheric/ocean CO2 instead of smokestack CO2.

  • JamesWimberley

    Useful and knowledgeable, as we’ve come to expect from Mike. But the definition of carbon sequestration is blinkered. There are at least three other technologies available.
    – Reafforestation. Technological preconditions : none, you just plant trees. Disadvantages; slow – a middle-sized tree will take 40 years or so to sequester one tonne of carbon; takes a lot of land. Bur reversing the recent deforestation in Brazil, the Congo, and Indonesia is doable.
    – Biochar burial. Technological preconditions : none;;not fully tested. Convert scrap wood and shrubs to charcoal (exothermic, so you can cash useful heat from the non-sequestered biomass) and plough it in. It improves the soil and takes a long time to re-emerge into the atmosphere. Or you can tip it into the deep ocean for a much longer cycle.
    – Olivine weathering. Olivine (link) is a very common magnesium silicate mineral – it makes up much of the Earth’s mantle. Scchuiling:
    “For the abundantly available magnesium-silicate olivine, the reaction is as follows:
    Mg2SiO4 + 4 CO2 + 4 H2O –> 2 Mg2+ + 4HCO3- + H4SiO4
    These bicarbonate solutions are carried by rivers to the sea, where they are ultimately
    deposited as limestones and dolomites. These carbonate sediments form the ultimate sink
    for CO2.”
    The idea is to accelerate this natural cycle by grinding olivine to sand and exposing it to winds. Disadvantages: slow, not fully tested.

    The fossil-fuel lobby has done a great disservice by getting carbon sequestration identified with an inherently expensive and iffy process of capturing CO2 from flue gas, liquefying it, then injecting undergroung. This does not work. The conclusion is not to give up on sequestration, but to try something else.
    .

  • ToddFlach

    Lord Kelvin, one of the great physicists and engineers of the 1800s, argued that manned flight was impossible…”because of physics”. His forecast for practical aviation (i.e., heavier-than-air aircraft) was negative. In 1896 he refused an invitation to join the Aeronautical Society, writing that “I have not the smallest molecule of faith in aerial navigation other than ballooning or of expectation of good results from any of the trials we hear of.” And in a 1902 newspaper interview he predicted that “No balloon and no aeroplane will ever be practically successful.”

    Yes, CCS costs money. But no, it is probably not close to its optimal state because it has only now begun to be tried at scale for power plants. Because it is more than just physics, it is also engineering.

    And also, Mike, the world has an acute need to remove CO2 from all industrial processes, not just power generation. Cement, steel, bioethanol, steam reforming of natural gas to produce ammonia for fertiliser without which billions of people would starve…these make up about 12% of all CO2 emissions. Their only practical solution for reducing their CO2 emissions is CCS.

    Steel for railways, wind turbines, substructures for offshore wind towers, biomass digester plants, cement for onshore and nearshore wind tower foundations,….

    Do not throw the baby out with the bathwater, do not let the perfect be the enemy of the good enough, etc..

    • Frank

      That sounds like a lot of cost and effort with nowhere near the payback of transitioning away from burning fossil fuels. It used to be expensive to do that, and now it’s an economy booster.

      • ToddFlach

        How do you propose to run the world’s cement, steel, nitrogen fertilizer industries (and other non-electric power plant industries) with renewables? Please share.

        • JamesWimberley

          – Cement: replace fossil with electric and solar heating (a Swiss team have demonstrated the latter in the lab). The 60% of the emissions from the chemistry of calcining is more difficult. There are experiments with different cement chemistries that actually fix carbon.
          – Steel: secondary steel (minimills running on scrap) is already electric. For primary, direct reduction reduces the carbon need, but it’s still there. On paper, you could use renewable hydrogen as the reducing gas; I don’t think this has been tried. Point to you. But an increasing proportion of steel is secondary; pig (primary) iron production in China has stopped growing.
          – Fertiliser: for the Haber process, al you need is heat and pressure. Electrify these.
          Do you have anything else?

          We can still have a carbon-neutral economy with limited specialised carbon-emitting processes, by offsetting with sequestration.

          • ToddFlach

            All your examples are indeed technically viable, but cost considerably more than current solutions, except recycling steel, which is already cheaper and widespread. But if it takes 150 USD per ton CO2 to make water electrolysis to work commercially as an alternative source of hydrogen to steam reforming methane, then CCS becomes competitve.

          • Frank

            Might be able to do some of that during times of over production, but my real point was that we are burning coal to produce electricity, and we should target that fist and fast because it is cheap, easy, and where the biggest numbers are.

          • neroden

            What Frank said. We can worry about the industrial processes later; the big kahuna is fossil fuels which are simply burned for energy, and we should get rid of those ASAP.

          • Bob_Wallace

            Let me tweak that a bit. We need to be worrying about industrial processes and looking for solutions. As we find solutions then we should implement them.

            At the same time we should be putting a lot of effort into removing fossil fuels from our grids and roads. We can do both at the same time.

          • ToddFlach

            The good news for now is that coal is rapidly losing market share for power production on just about every continent, except perhaps the Indian sub-continent. Coal mining companies are going bankrupt in droves, and nobody wants to buy up the scraps, so coal for power is doomed. The bad news is that a lot of natural gas is coming in to replace coal. Renewables are catching up fast but this will take 10-20 years to complete, and there will still be a residual natural gas power generation fleet in operation. Why not use CCS on that last15-20% of the electric power market running on natural gas?

          • Bob_Wallace

            CCS for NG plants? Why not. If we can make sure the carbon is stored long term. At least a couple hundred years which would give future generations time to get a re-sequestration/offset program in place.

            CCS would drive up the cost of electricity coming from NG plants which would make stored clean electricity more competitive and drive the use of NG even lower.

          • Tom Capon

            Of course it would be nice if we could limit the demand for nitrogen fertilizers. That would go a long way toward maintaining the “blue carbon sink” ecosystems Dan mentioned above.

        • neroden

          There are two different carbon-negative concrete formulations available already.

          Artificial nitrogen fertilizer has very severe sustainability problems waaaay beyond the carbon emissions and I’m not going to get into it except to say that we have to stop using it. That said, there is at least one renewable ammonia process which I know of.

          Steel is hard.

          • ToddFlach

            Agree that too much artificial fertiliser is produced and used today. But shrinking that to zero would certainly reduce our food production in the short- medium term as soil management practices proceed to improve to the point we can manage without the artificial fertiliser. Why not use CCS on that last residual artificial fertiliser production that we cannot manage without? It is not too early to reduce CO2 emissions from ANY source-quite the opposite- we need silver buckshot-not silver bullets.

    • Hans

      Put a proper price on carbon and let the market decide who wins: renewable energy or coal power + CCS

      • ToddFlach

        Horses for courses. Many places have great sun, wind, hydro, geothermal, etc. But many, many places and countries do not. But they have in many cases fossil fuels. Renewables will never “win” in these locations. Why deny them using CCS for these?

        • Ross

          A carbon price will provide the clearest signal to deter harmful activities.

          It is a dubious claim that there are many places where an adequate combination of renewables, distribution, demand management, storage, and interconnectors doesn’t beat FF+CCS.

          • Frank

            Personally, I don’t think we should limit ourselves to CO2, but I love the “put a price on it”. There is no better way to come up with a bunch of efficient nuanced solutions than to give a few billion people a reason to figure it out.

        • JamesWimberley

          “But many, many places and countries do not.”
          [cite]
          Solar is being installed in Scotland and wind in Germany. You do not need “great” sun and wind.

          • ToddFlach

            “Being installed” is fantastic, which I fully suport, but it is still a long, long way from complete replacement of ff.

        • Bob_Wallace

          What countries do not have ample renewable energy resources?

          • ToddFlach

            Poland, Latvia, Estonia, Lithuania, Belarus, and numerous other central European countries with little wind or hydro and grey, long, cold winters.

          • Mike Gitarev

            Latvia get’s about 75% electricity from large hydro.

          • ToddFlach

            That is better than I was aware of, thanks for the input. Now what to do about that last 25%. If it is currently legacy nuclear power from the soviet period, it will need to be replaced soon.

          • Mike Gitarev

            Could you please at least check CIA Factbook or EIA statistic before giving out “opinions” about ex-USSR energy system?
            There was nuclear power station in Luthuania, closed in 2009 beacuse of EU don’t want it.

            Belarus is now building their first, with Russa, all others are discussing to cooperatively build single Visaginas in Lithuania.

          • Bob_Wallace

            Here’s a link to an interactive map on which you can find the mix of renewables that Jacobson and his group have determined the best mix (at this point in time) for each of those countries to get 100% of their energy from renewables.

            https://100.org/wp-addons/maps/embed-large.html

            And you can read more about their work here –

            http://www.scientificamerican.com/article/139-countries-could-get-all-of-their-power-from-renewable-sources1/

          • ToddFlach

            Thanks for the links, Bob. I scanned the technical paper briefly by Jacobsen et al. and found little discussion on the technical and commercial feasibility limits and challenges. If we assume a transmission grid that connects the sunniest and windiest and geothermaliest regions to those that lack these, then yes a 100% renewable energy system can be done for whole continents independent of national borders. Here in Norway there are now plans to connect the Norway and UK grids with a subsea cable with a capacity of 1400 MW. So where there is a business model there is a way.

        • Greg Cragg

          I have two ways to make energy from waste, as well I have a way to double solar’s energy, these solutions could be used in every country, as well ways to pay for all!

    • Some of your points are reasonable. Perhaps if I’d said CCS was impossible instead of uneconomically expensive you might have come across more reasonably.

      But having spent time in the distribution industry among several others and worked with the Global Thermostat principles on approaches for air carbon capture for freight rail and having done the math on several sequestration approaches and having a good lay understanding of commodities, I’m comfortable that CCS will remain improbably uneconomic without a very serious price on carbon.

      When that occurs, the Caldera process for sequestering CO2 in cement for example will become economic and widespread.

      http://www.scientificamerican.com/article/cement-from-carbon-dioxide/

      Yes, there needs to be a concerted effort to decarbonize the areas you mention, but you don’t seem to realize what’s actually possible there.

      I’ll just repeat myself. The big emitters are electrical generation and transportation. Stopping burning fossil fuels for those two sectors is the majority of the solution, not CCS on burning fossil fuels for those sectors. Everything else is mopping up around the edges. Important to do, but irrelevant if we pretend CCS will deal with the heavy lifting.

      Like nuclear, CCS is a small and expensive wedge, but CCS is smaller and more expensive. Wind and solar electrical generation and electrification of transportation are the big wedges.

      • ToddFlach

        I think we can agree that a serious price on carbon is necessary for any transition to a zero-emissions infrastructure. Once that serious price (150 USD/ton CO2?) is in place, then CCS will be a commercially viable option for many different plants that use ff.

        • Yes, absolutely.

          The calculated price points that I’ve seen for the negative externalities for CO2 emissions range from $60 to $120 per ton. That’s the range we need to talk about. At the top end of the range, the bottom end of the CCS cost point becomes a wash.

          But at $120 per ton, gas increases in cost by 28% in Canada as one example, the cost of extracting, distributing and processing a barrel of oil from the oil sands goes up by 5% at 2015 oil prices (which is significant for an already expensive source of oil), coal and gas still have to pay the $120 on CCS just to not incur the carbon tax, so will still be uneconomically priced, etc.

          Basically, a high carbon tax will force a rapid transition away from fossil fuels while making some CCS to clean up the edges viable.

    • neroden

      CCS is unusable for power plants. The energy economics are impossible; you invariably use more energy converting the CO2 back into a stable form than you got from the burning of fuel.

      Industrial processes like cement, steel, and ammonia — replacing those with carbon-negative processes, *that* is realistic.

      • ToddFlach

        The energy penalty for CCS is about 20-25%. So a combined cycle PP without CCS has about 58% efficiency. Retrofitting CCS will reduce that to about 44-46% efficiency. This is well within commercial viability when CO2 emissions taxes get to about 100 USD/ton or more.

    • Dan

      There’s potential in aquaponics for reducing the need for artificial nitrogen fixing. Just let microbes do their thing with some fish poop. I dream that vertical urban aquaponic farms will allow open spaces (monoculture) to return to prarie and that biodiversity will strengthen natural carbon sequestration and water quality. Prarie plants have deep roots which have excellent impacts on water retention, filtering, and do sequester carbon. Every little bit counts

    • Matt

      “According to an organization which promotes carbon capture and sequestration, it will cost $120-$140 per ton of CO2.”
      So sounds like to me, the most efficient way to move forward would be to start a carbon fee/dividend system. Set the start rate at $150/ton this would give CCS a chance to prove itself. Raise the cost over time to related health care cost (additional $50-$150/ton), then can look at adding other externals in. So start at $150/ton and go up either month($10) or quarterly($25). Return equal share to each tax dividend. Just the announcement that it was coming would shift the markets to move it the correct direction. If it is cheaper to CCS than let it fly it will happen.

  • Dan

    I thought this was relevant;

    The ocean’s vegetative habitats, including mangroves, salt marshes and seagrasses, cover less than 0.5% of the sea floor. Blue carbon sinks are responsible for over 50%, perhaps as much as 71% of all carbon storage. They represent only 0.05% of the plant biomass on land, but store a comparable amount of carbon per year, and thus rank among the most intense carbon sinks on the planet. Blue carbon sinks and estuaries capture and store between 235-450 Tg C per year, equivalent to almost half of global emissions from transport sector, estimated at around 1,000 Tg C year. By preventing the loss and degradation of these ecosystems and catalyzing their recovery can contribute to offsetting 3-7% of current fossil fuel emissions (totaling 7,200 Tg C per year) in two decades, more than half of that projected for reducing the effect of deforestation. (Nelleman C, et al., 2009)

    The rate of loss of these marine ecosystems is much higher than any other ecosystem on the planet, in some cases up to four times that of rainforests. Currently, on average, between 2-7% of our blue carbon sinks are lost annually, an increase of seven times compared with only half a century.

    Retain blue carbon sinks is crucial for establishing adaptation strategies based on ecosystems that reduce the vulnerability of human coastal communities to climate change. Stop the degradation of ocean and coastal ecosystems would also generate income, improve food security and livelihoods in coastal areas. It would also provide greater economic and development opportunities for coastal communities around the world, including the Small Island Developing States. (Nelleman C et al., 2009)

    • JamesWimberley

      Thanks. Useful and news to me.

      • Dan

        Absolutely, kill two birds with one stone. Or rather save two halves of the world with one plan, restoring ocean habitats and the atmosphere! 🙂 Bill Nye had an interesting idea in his book Unstoppable. Hydrosols (tiny bubbles) could be produced by some mechanism on the back of cargo ships. They make the surface more reflective and help compensate for the loss of ice at the poles. This would reduce solar gain and could possibly help oxigenate the ocean, stimulating sea life. Definitely a thorough biological analysis is warranted before a large scale experiment like that should be put into practice, but its relatively cheap I imagin and more feasible than anything like huge mirrors or dispersing some particals in the atmosphere. Its the lowest impact idea i’ve heard to reduce global temperatures.

        • Matt

          While in the end, unless mother nature helps with a early mini ice age, geo-engineer is likely because we wasted so much time deciding to act. The problem is unintended side effects. I seen lots of proposals, fleet of robotic sail boats in ocean pumping water into the air to make more clouds is one. But all require funding to make happen, and who controls them?

          • Dan

            We probably will be having to do some geo-engineering but we have a lot to learn still. I think natural approaches should be the only ones we focus on now while also getting to 100% Renewables as fast as humanly possible. Everything we do requires energy so as long as we are using fossil fuels we are not solving the problem. The Venus Project has some beautiful concepts for ocean cities which are nice for the sake of something to aspire to. Putting a tax or fee on Carbon Emmisions or even a simple fee on oil specifically because the price has dropped so far recently might be a great way to find stimulus funds for renewable infrastructure or smartgrid stuff. By the time we are operating at near 100% Renewables, maybe I’m being a naive optimist, I think we could utilize emmense energy projects, guilt and emmision free, for geo-engineering like you talked about. The Hydrosols idea is still the best I’ve heard imo because cargo ships are already going every which way across the ocean and could relatively evenly impact the reflective surface with the shiny bubbles. It’s relatively low energy to produce bubbles and with significant improvements in solar costs/efficiencies entire ships may just run off the sun and help cool the oceans. Without a resilient renewables infrastructure and production capacity (solar cell factories) we would be kinda screwed if market disruptions cut supply chain for key things we need to keep everything running. We really need to focus on solar and wind for now i think. Also… earthships are awesome if you are personally looking for a resilient home for a “worst case scenario”.

  • Ross

    Epic smackdown. Will the last one out please turn-off the lights?

    • ToddFlach

      The tone of the article was in my opinion professional and factual, and even though it was one-sided, it was not at all attempting to perform a “smackdown”.
      Thanks, Mike, for promoting civilized discussion.

      • Ross

        I was using the informal term in the sense of “a decisive blow”.

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