Carbon-negative energy gets boost as UNFCCC includes CCS in CDM mechanism

Very important news: the capture and sequestering underground of carbon dioxide from power plants will earn carbon credits under the Kyoto Protocol, following amendments to the treaty’s main carbon trading scheme. A UNFCCC official says approval has been given for so-called carbon capture and storage (CCS) projects to claim Certified Emission Reduction (CER) credits under the Kyoto Protocol’s Clean Development Mechanism (CDM).

Jose Miguez, a member of the CDM Executive Board, said the CDM would be expanded to cover some specific CCS activities in the upcoming first Kyoto commitment period to 2012. Projects would only be eligible in developing countries where at least half the nation’s electricity is generated from burning coal.

Carbon-negative energy ever more closer
This means, very importantly, that so-called 'bio-energy with carbon storage' (BECS) systems will be eligible for the credits too, which is what the bioenergy community has been asking. With this decision, the revolutionary potential of BECS can finally begin to be realised and transform the world's energy production systems - starting in developing countries.

The techniques currently being developed for the capture and geosequestration of carbon can be applied to biomass instead of coal, and thus deliver carbon-negative fuels and energy. Renewables like wind, solar, hydro or geothermal are all carbon-neutral. That is, they merely prevent the release of emissions in the future. Carbon-negative bioenergy and biofuels on the contrary clean up emissions from the past. They take back what we emitted years ago.

Scientists who developed BECS concepts within the context of 'Abrupt Climat Change' (ACC) scenarios, project that BECS systems can reduce atmospheric CO2 levels rapidly, safely and without the need for alternative and risky geo-engineering interventions. If implemented on a global scale, BECS can bring atmospheric CO2 back to pre-industrial levels by mid-century (earlier post and especially here).

Geo-engineering, the safe way
Some have suggested that we are already facing a future of catastrophic climate change and that this calls for radical geo-engineering solutions. One of the least controversial of the ideas is the use of 'synthetic trees' - machines that capture CO2 and sequester it underground. The problem is that the idea represents a costly intervention, and does not replace the polluting fossil fuels that are responsible for the problem in the first place.

BECS systems are based on the same principle, but use real trees instead. Contrary to the synthetic trees, BECS systems yield energy while capturing CO2. As energy crops grow, they store carbon. When they are transformed into useable energy, the carbon released is captured via a range of techniques (pre-combustion, oxyfuel or post-combustion capture), and then locked away. The balance is carbon-negative energy in the form of electricity, heat, or liquid and gaseous fuels. In short, BECS systems allow societies to keep using energy as usual, while cleaning up their past emissions.

This is a far less radical approach than some of the more questionable geo-engineering options presently on the table, which would require societies to power down, with all the risks this entails. Some of these proposals include:
energy :: fossil fuels :: biomass :: bioenergy :: biofuels :: climate change :: carbon capture and storage :: bio-energy with carbon storage :: UNFCCC :: Kyoto Protocol :: Clean Development Mechanism :: carbon credits :: carbon-negative ::

Seeding the oceans with iron to ensure that algae sequester carbon dioxide which would then drop to the bottom of the ocean (earlier post), creating artificial clouds that reflect sunlight back into the atmosphere and lead to global cooling, or launching billions of tiny mirrors into space to prevent sunlight from reaching the planet. The most controversial proposal is the suggestion that mitigating global warming could be accomplished by emulating a volcanic eruption because volcanic aerosols scatter incoming sunlight, reducing outgoing radiation. Rockets full of sulphur particles would be launched into the upper atmosphere and envelop the earth in a blanket of aerosols. Scientists advise against this idea because it is too risky (more here).

The BECS-concept could be seen as a geo-engineering option that is much more feasible, far less costly and virtually risk-free. 'Geo-engineering', because it requires the establishment of vast energy plantations across the globe, the biomass of which must replace coal.

Because of the confluence of several factors, this idea is becoming more and more feasible. First, there is vast potential for energy crops in the South. Projections by the International Energy Agency's Bioenergy Task 40, which looks at this potential, assesses the biomass potential to be as high as 1300 Exajoules worth of energy by 2050 (this is roughly three times as much energy as the total amount of energy used today by the entire planet from all sources, - coal, oil, gas, nuclear) (more here).

An EU-study looked at things in a more concrete way. It asked what the potential is for tropical tree crops that might be used for the production of green steel. Its conclusion: there are more than 46 million hectares of suitable land available in Central Africa (southern Congo, the western part of the Democratic Republic of Congo, northern and eastern Angola, western Zambia, western and southern Tanzania, northern Mozambique and the western and central parts of the Central African Republic), and another 46 million in Brazil. There, fast growing and high yielding trees like Eucalyptus can be grown in a reasonably sustainable manner (earlier post).

Many other biomass crops can be grown in other parts of the subtropics and the tropics, where land-use is extremely limited and much arable land is available without the threat of a conflict between food and fuel production, and without the need for deforestation (see the IEA projections).

A second factor is the progress made by scientists in developing ever better crops for bioenergy. Examples are myriad, but we will refer only to a most recent one: the design of a eucalyptus tree that sequesters far more carbon dioxide than normal trees, and has a lower lignin content (earlier post). This is an important example, because the more CO2 a tree captures, the more of it can be sequestered when used in BECS-systems.

A third reason is the advances made in the design of highly efficient bioconversion processes that are becoming competitive with oil, gas and coal. Some of these include new biogas, gasification, biomass-to-liquids and combustion processes. Some of these can already be coupled to CCS technologies.

Finally, BECS can be decoupled from power generation. This means that a geosequestration site (e.g. a depleted oil or gas field) can be selected independently of the location of a power plant but in function of the local biomass production potential. Biomass would be grown close to the sequestration site, converted into a (gaseous or liquid) biofuel, the CO2 captured and stored, and the ultra-clean, carbon-negative fuel shipped out to end-markets.

For all these reasons, BECS-systems become flexible concepts that can be applied in a wide range of contexts and that can rely on the large global potential for the production of dedicated biomass.

Growing awareness
The BECS-concept is only gradually permeating the minds of the energy and climate communities. But some concrete projects are underway that hint at its potential. Recently we discussed a study by the U.S. Department of Energy’s National Energy Technology Laboratory (DOE/NETL) and the U.S. Air Force (USAF) focused on a highly advanced generation of fuels made from combining the liquefaction of both coal and biomass, and then coupling the system to carbon sequestration technologies. It's a mouthful, but the radical concept comes down to: coal+biomass-to-liquids (CBTL) + carbon capture and storage (CCS), or CBTL+CCS. The CBTL process consists of the production of so-called synthetic fuels, obtained from the gasification of feedstock, with the gas then liquefied via Fischer-Tropsch synthesis into an ultra-clean synthetic fuel. If the coal is left out and biomass is used exclusively, the fuel becomes carbon-negative.

The above example is one based on the production of fuels, not power and electricity. Alternatives to this concept are the production of ultra-clean carbon-negative biomethane. Energy crops are digested anaerobically after which the CO2 fraction is scrubbed out of the gas via pre-combustion techniques. The carbon dioxide is then ready to be sequestered. Pure carbon-negative biomethane can then be shipped to markets.

But BECS-systems will find their most wide and earliest applications in power plants, in settings similar to CCS coupled to coal plants. The CCS-techniques can be applied to fully dedicated biomass power plants that burn wood or biomass pellets instead of coal. However, in a first stage, it is most likely that biomass will be co-fired in coal plants to which CCS is applied. Several 'clean coal' projects are now beginning to grasp the fact that the inclusion of biomass as a fuel could make the fuel carbon-negative instead of merely carbon-neutral.

For example a new CCS project announced by Praxair and Foster Wheeler explicitly hints at the inclusion of biofuels (earlier post); it calls these still 'opportunity' fuels, but with the advent of global biomass trade and given the huge potential for its sustainable production in the South, biomass will soon transit from an opportunity fuel into a main fuel in power plants.

The fact that the UNFCCC is set to include CCS for carbon credits in the CDM, implies that BECS could be introduced first in the South, precisely there where large-scale sustainable biomass production is most feasible.


References:
Carbon Positive: CCS given Kyoto green light - September 19, 2007.

Biopact: A closer look at the revolutionary coal+biomass-to-liquids with carbon storage project - September 13, 2007

Biopact: En route to carbon-negative energy: Praxair and Foster Wheeler team up to pursue carbon capture demonstration projects - September 18, 2007

Biopact: IEA report: bioenergy can meet 20 to 50% of world's future energy demand - September 12, 2007

Biopact: Climate change and geoengineering: emulating volcanic eruption too risky - August 15, 2007

Biopact: Capturing carbon with "synthetic trees" or with the real thing? - February 20, 2007

Biopact: Green steel made from tropical biomass - European project - February 08, 2007

Biopact: Scientists develop low-lignin eucalyptus trees that store more CO2, provide more cellulose for biofuels - September 17, 2007