Towards carbon-negative bioenergy: scientists develop low-cost material for capturing carbon dioxide from smokestacks
If these carbon capture technologies are coupled to biomass power plants, they can yield "negative emissions" energy - by far the most radically green type of energy. So-called carbon-negative bioenergy, based on capturing and storing biogenic CO2, actively removes carbon dioxide from the atmosphere. Other energy technologies like solar or wind power remain 'carbon neutral' at best, slightly carbon positive in practise: during their lifecycle, they add small amounts of CO2 to the atmosphere, but they can never remove the greenhouse gas from it.
Driving an electric car the batteries of which were charged by this carbon-negative electricity would imply that you would be fighting climate change. In fact, the more you were to drive it, the more you were to prevent global warming. According to scientists fromt the Abrupt Climate Change Strategy group, such BECS systems can cool the planet and bring back atmospheric CO2 levels to pre-industrial levels by mid-century, if applied on a global scale - either in power plants coupled to carbon capture and storage that burn biomass instead of fossil fuels, or in bio-hydrogen production facilities.
One of the major bottlenecks towards the development of carbon-negative bioenergy is the creation of low-cost, efficient carbon capture technologies. In their new study, Christopher W. Jones and colleagues point out that existing carbon capture technology is unsuitable for wide use. Absorbent liquids, for instance, are energy intensive and expensive. Current solid adsorbents show promise, but many suffer from low absorption capacities and lack stability after extended use. Stronger, longer-lasting materials are needed, scientists say.
But the scientists now describe the development of a promising new solid adsorbent, coined a hyperbranched aminosilica (HAS), that avoids most of these problems:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biohydrogen :: decarbonisation :: carbon capture :: bio-energy with carbon storage :: climate change ::
The HAS was synthesized by a one-step reaction, spontaneous aziridine ring-opening polymerization off of surface silanols, to form a 32 wt % organic/inorganic hybrid material. The adsorption measurements were performed in a fixed-bed flow reactor using humidified CO2.
When compared to traditional solid adsorbents under simulated emissions from industrial smokestacks, the new material captured up to seven times more carbon dioxide than conventional solid materials, including some of the best carbon dioxide adsorbents currently available, the researchers say. The material also shows greater stability under different temperature extremes, allowing it to be recycled numerous times.
References:
Jason C. Hicks, Jeffrey H. Drese, Daniel J. Fauth, McMahan L. Gray, Genggeng Qi, and Christopher W. Jones, "Designing Adsorbents for CO2 Capture from Flue Gas-Hyperbranched Aminosilicas Capable of Capturing CO2 Reversibly", J. Am. Chem. Soc., 130 (10), 2902 -2903, 2008. 10.1021/ja077795v S0002-7863(07)07795-5
More on carbon-negative bioenergy:
H. Audus and P. Freund, "Climate Change Mitigation by Biomass Gasificiation Combined with CO2 Capture and Storage", IEA Greenhouse Gas R&D Programme.
James S. Rhodesa and David W. Keithb, "Engineering economic analysis of biomass IGCC with carbon capture and storage", Biomass and Bioenergy, Volume 29, Issue 6, December 2005, Pages 440-450.
Noim Uddin and Leonardo Barreto, "Biomass-fired cogeneration systems with CO2 capture and storage", Renewable Energy, Volume 32, Issue 6, May 2007, Pages 1006-1019, doi:10.1016/j.renene.2006.04.009
Christian Azar, Kristian Lindgren, Eric Larson and Kenneth Möllersten, "Carbon Capture and Storage From Fossil Fuels and Biomass – Costs and Potential Role in Stabilizing the Atmosphere", Climatic Change, Volume 74, Numbers 1-3 / January, 2006, DOI 10.1007/s10584-005-3484-7
Peter Read and Jonathan Lermit, "Bio-Energy with Carbon Storage (BECS): a Sequential Decision Approach to the threat of Abrupt Climate Change", Energy, Volume 30, Issue 14, November 2005, Pages 2654-2671.
Stefan Grönkvist, Kenneth Möllersten, Kim Pingoud, "Equal Opportunity for Biomass in Greenhouse Gas Accounting of CO2 Capture and Storage: A Step Towards More Cost-Effective Climate Change Mitigation Regimes", Mitigation and Adaptation Strategies for Global Change, Volume 11, Numbers 5-6 / September, 2006, DOI 10.1007/s11027-006-9034-9
4 Comments:
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Frankly your constant repetition of this "the more carbon-negative energy you use the more you help the environment" line is getting stale. There are other costs to profligate energy consumption besides carbon dioxide emissions, and any effort to address the environmental costs of energy consumption *must* include an improvement in efficiency, despite the grandiose upper estimates of sustainable bioenergy potential.
It's also faintly ridiculous to harp on CO2 capture and storage in an economy where coal continues to provide the vast majority of the world's combustible electric generation fuel and the coal industry holds most of the commercial interest in carbon dioxide capture technology, which it chooses not to deploy in existing power stations. By far the cheapest way to "sequester" carbon is to leave it in the ground, unburnt. But for this to happen, the big, inefficient fuel-burning thermal power stations will have to be retired as cleaner, smaller-scale (and ultimately cheaper) technologies mature and are widely deployed.
Harping on CCS as a vital technology sounds very much like an endorsement of existing centralised energy conversion arrangements based on fossil fuels.
(Why doesn't blogger accept <sub> tags?)
It is my understanding that many existing and emerging commercially-viable technologies already offer much cheaper marginal CO2 emissions reductions in the electricity industry than CCS might ever do. CCS is at best a costly, tack-on measure.
These cheaper emissions reductions are achieved through end-use efficiency, improvements in energy conversion efficiency, fuel-switching to low-carbon natural gas (substituting biogas as fossil gas supplies deplete), bioenergy *without* carbon capture, nuclear power, and carbon-neutral ambient energy capture with small-hydro, geothermal, wind, solar thermal, photovoltaic, tidal and wave technology. Most of these technologies are experiencing much the same advances as bioenergy and biotechnology.
It will likely be many decades before CCS becomes viable for use on the same scale as coal is burned today. 'Sustainable' biomass co-firing in those large power stations that make CCS attractive is gradually increasing, but is likewise unlikely to displace coal for many decades. As long as coal without CCS provides baseload electricity around the world, small carbon-capture projects at other 'clean energy' installations are mere tokenism.
Biomass electricity generation, particularly on a relatively small scale, is vital for the expansion of modern energy services into new markets. But for these applications CCS is unlikely to be attractive.
Xoddam, our site and work does not really concern energy use in the developed world, but rather development in less developed countries.
There energy consumption is crucial for societies to get out of poverty and to make social progress.
We would prefer these societies to use low-carbon technologies. Very few of the things you propose make sense in the developing world.
Efficiency does, and a switch from fossil fuels to biomass does to. Other renewables can perhaps contribute, even though the potential is quite small. But obviously scaling back on energy consumption is not an option, and even dangerous for these countries (and for the environment).
As you know, there's a strict correlation between clean development and access to abundant and low-cost energy.
We hammer on bioenergy+CCS because it will be one of the most efficient and cost-effective low carbon technologies. We think this technology should be developed switfly, so it can be transferred to the South asap. Developments are going quite rapidly, so that's really good.
We would prefer to see China cofire bioenergy and couple its plants to CCS. It's not like solar or wind are going to contribute much to such an economy that needs reliable baseloads and cheap energy to consolidate its development. (An expansion of wind or solar implies an expansion of the coal industry; we prefer that to be the biomass industry).
So please, keep in mind that the world is bigger than Europe and America, where it is easy to talk of expensive technologies with very little negative impacts. These don't make sense elsewhere.
Finally, we are pragmatic about CCS. This is going to be developed by the fossil fuel industry anyways, so we - and we are the only ones out there - stress that IF this technology is going to be used, it should be used on biomass from the very start.
Our motto is: everything the coal industry does, can and will be used against it.
Please check our website. It's more about energy in the developing world, and potential trade relations in bioenergy.
Regards,
Jonas
Thanks Jonas.
I know pretty well what your agenda is, and I support it wholeheartedly. I've been a regular reader for some time now.
I understand that your agenda comes out of an agriculture-policy point of view first and from the energy-technology perspective second, but I'm really excited by many of the technologies you've reported. The prospect of maintaining methane fuel supply beyond fossil gas depletion is a tremendous relief to me; because it is by substituting gas for coal that many of the cheapest, most promising technical efficiency improvements and CO2 emissions reductions can be achieved.
I agree that biofuels are the most promising solution to declining petroleum production. I agree that in countries with high biomass production potential, this is likely to prove the most cost-effective way to deliver modern energy services to the population.
On the other hand I disagree vehemently with the idea that gas, wind and solar power are any less applicable in developing countries than biomass, coal or nuclear power; or are worth less to poor societies than they are to rich ones. These are *not* mere expensive white elephants salving the conscience of wealthy consumers, but valuable energy technologies in their own right, as their escalating deployment and decreasing cost demonstrates.
I cannot picture any North African country, or Spain or Australia for that matter, turning to biomass for its electricity supply. Biomass potential is severely limited in southeast Asia without devastating deforestation. The Sahel, which might in an ideal world of reliable monsoons become a biofuel powerhouse, also faces the risk of losing altogether its notoriously fickle rainfall as a consequence of global warming. But solar thermal technology is ideal for these climates and actually benefits from low rainfall.
Ambient energy collection and CO2 capture and storage *alike* are precisely as useful and as cost-effective in developing countries as they are in wealthy countries. That is, CCS is not yet considered cost-effective and may never be, while ambient energy machines are.
Developing countries *already* deploy hydroelectricity, micro-hydro, wind turbines and even photovoltaics widely, without subsidy. Solar thermal is beginning to follow already, and hot-dry-rock geothermal power, once the technology is proven, will too.
My main point is that other carbon-neutral energy technologies are experiencing the same technological revolution as bioenergy, and that they therefore should not be dismissed in the quest for emissions reductions. Bioenergy, wind, geothermal and solar power are all real, widely-deployed technologies with plunging costs and impressive growth figures in developing countries as well as in wealthier ones.
Carbon-dioxide capture is not comparable, and since it offers *only* an additional cost (without the economic benefit of avoiding paying for fuel altogether), I don't expect it ever to achieve the same momentum.
None of what I've said about CCS applies to biochar. I consider that a very promising technology indeed.
Xodddam,
I agree with almost everything you say, except that our focus is still more specific!
Not North-Africa, but Sub-Saharan Africa. It would be foolish for Algeria or Libya not to invest in solar energy or for Morocco in wind.
But these are largely relatively well developed, rather urbanised countries.
Our focus is, as you say, on rural countries in SSA.
You're right in saying that renewables are growing rapidly.
But just think of scale. Currently they mean nothing compared to the fossil fuel industry.
Coal and gas make up the bulk of the world's electricity fuels and the stakes are trillion dollar stakes.
The coal and gas industry will want to survive, and CCS is the only key to survival.
The coal sector has the billions to invest in developing CCS, and it is doing so.
That's why I think carbon capture and storage will be implemented on a large scale, much faster than thought.
Idealistically speaking it would be best if we were to close all coal plants, steal their money and spend it on renewables instead.
But that's just not very realistic.
So again, given that CCS will be developed swiftly, it is interesting to stress that it can be used on biomass.
There's also a nuance to be made regarding the economic value of avoiding CO2 via CCS: in the case of coal this is a pure extra cost; but in the case of biomass this is not the case. With biomass, you actually get two credits: one for using biomass in the first place, and one for removing the CO2 from it.
CCS will be incorporated in emissions trade / CDM. So it will not merely be a pure cost factor.
Finally, you point to biochar: I'm a much bigger fan of biochar than of bioenergy+CCS, but we just try to report on all potential options.
Best,
Jonas
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