Major CO2 Mitigation Methods: Carbon sequestering, Biochar and more

Straight up storing CO2 as a gas in the ground or saline is happening now at several tens of millions of tons/year worldwide. The amount of CO2 offset by solar power is on the same scale. Civilization is generating abut 25 billion tons of CO2 per year. Nuclear power worldwide offsets 2 billion tons of CO2 per year. Plus when CO2 is used to get more oil then it is not a net reduction depending on how it accounted. Of course getting towards CO2 neutrality by storing as you use and getting more oil is better than using oil/coal and not storing. Plus enhanced oil recovery also helps with Peak Oil, which is a good and necessary thing on the way to better solutions.

1. Biochar sequestering
The fertile black soils in the Amazon basin suggest a cheaper, lower-tech route toward the same destination as carbon storage. Scattered patches of dark, charcoal-rich soil known as terra preta (Portuguese for “black earth”) are the inspiration for an international effort to explore how burying biomass-derived charcoal, or “biochar,” could boost soil fertility and transfer a sizeable amount of CO2 from the atmosphere into safe storage in topsoil.

Charcoal is traditionally made by burning wood in pits or temporary structures, but modern pyrolysis equipment greatly reduces the air pollution associated with this practice. Gases emitted from pyrolysis can be captured to generate valuable products instead of being released as smoke. Some of the by-products can be condensed into “bio-oil,” a liquid that can be upgraded to fuels including biodiesel and synthesis gas. A portion of the noncondensable fraction is burned to heat the pyrolysis chamber, and the rest can provide heat or fuel an electric generator.

Pyrolysis equipment now being developed at several public and private institutions typically operate at 350–700°C. In Golden, Colorado, Biochar Engineering Corporation is building portable $50,000 pyrolyzers that researchers will use to produce 1–2 tons of biochar per week. Company CEO Jim Fournier says the firm is planning larger units that could be trucked into position. Biomass is expensive to transport, he says, so pyrolysis units located near the source of the biomass are preferable to larger, centrally located facilities, even when the units reach commercial scale.

Steiner and coauthors noted in the 2003 book Amazonian Dark Earths that the charcoal-mediated enhancement of soil caused a 280–400% increase in plant uptake of nitrogen.

Preliminary results in a greenhouse study showed that low-volatility [biochar] supplemented with fertilizer outperformed fertilizer alone by 60%.

Because the heat and chemical energy released during pyrolysis could replace energy derived from fossil fuels, the IBI calculates the total benefit would be equivalent to removing about 1.2 billion metric tons of carbon from the atmosphere each year. That would offset 29% of today’s net rise in atmospheric carbon, which is estimated at 4.1 billion metric tons, according to the Energy Information Administration.

2. Regular Carbon Sequestering
The MIT Future of Coal 2007 report estimated that capturing all of the roughly 1.5 billion tons per year of CO2 generated by coal-burning power plants in the United States would generate a CO2 flow with just one-third of the volume of the natural gas flowing in the U.S. gas pipeline system.

The technology is expected to use between 10 and 40% of the energy produced by a power station.

In 2007, Jason Burnett, EPA associate deputy administrator, told USINFO. “Currently, about 35 million tons of CO2 are sequestered in the United States,” Burnett added, “primarily for enhanced oil recovery. We expect that to increase, by some estimates, by 400-fold by 2100.”

The Japanese government is targeting an annual reduction of 100 million tons in carbon dioxide emissions through CCS technologies by 2020.

Industrial-scale storage projects are in operation.
Sleipner is the oldest project (1996) and is located in the North Sea where Norway’s StatoilHydro strips carbon dioxide from natural gas with amine solvents and disposes of this carbon dioxide in a deep saline aquifer. Since 1996, Sleipner has stored about one million tonnes CO2 a year. A second project in the Snøhvit gas field in the Barents Sea stores 700,000 tonnes per year.

The Weyburn project (started 2000) is currently the world’s largest carbon capture and storage project. It is used for enhanced oil recovery with an injection rate of about 1.5 million tonnes per year. They are investigating how the technology can be expanded on a larger scale.

A natural gas reservoir located in In Salah, Algeria. The CO2 will be separated from the natural gas and re-injected into the subsurface at a rate of about 1.2 million tonnes per year.

Australian has a project to store 3 million tons per year starting in 2009. The Gordon project, an add-on to an off-shore Western Australian Natural Gas extraction project, is the largest CO2 storage project in the world. It will attempt to capture and store 3 million tonnes of CO2 per year for 40 years in a saline aquifer, commencing in 2009. It will cost ~$840 million.

CO2 capture from the air.

Wide plan proposes €1.25bn for carbon capture at coal-fired power plants; €1.75bn earmarked for better international energy links. The European commission today proposed earmarking €1.25bn to kickstart carbon capture and storage (CCS) at 11 coal-fired plants across Europe, including four in Britain.The four British power stations – the controversial Kingsnorth plant in Kent, Longannet in Fife, Tilbury in Essex and Hatfield in Yorkshire – would share €250m under the two-year scheme.

Japan and China have a project will cost 20 to 30 billion yen and will involve the participation of the Japanese public and private sectors, including JGC Corp. and Toyota Motor Corp. The two countries plan to bring the project into action in 2009. Under the plan, more than one million tons of CO2 annually from the Harbin Thermal Power Plant in Heilungkiang Province will be transferred to the Daqing Oilfield, about 100 km from the plant, and will be injected and stored in the oilfield.

3. CO2 into Cement

Novacem is a company that is making cement from magnesium silicates that absorbs more CO2 as it hardens. Normally cement adds a net 0.4 tons of CO2 per ton of cement, but this new cement would remove 0.6 tons of CO2 from the air. There is an estimated 10 trillion tons of magnesium silicate in the world. 0.6 tonnes times 10 trillion tons is 6 trillion tons. The amount of CO2 generated by people is 27 billion tons worldwide and this could increase to 45 billion tons. So 6 trillion tons is about 200 years worth of CO2 storage.

Calera cement is a startup funded by Vinod Khosla, technology billionaire. Calera’s process takes the idea of carbon capture and storage a step forward by storing the CO2 in a useful product. For every ton of Calera cement that is made, they are sequestering half a ton of CO2.

Calera Cement Process uses flue gas from coal plants/steel plants or natural gas plants + seawater for calcium & Magnesium = Cement + Clean water + Cleaner Air

Calera has an operational pilot plant.

4. Low Carbon Energy Sources

Nuclear power worldwide offsets 2 billion tons of CO2 per year. Scaling nuclear power, wind energy, solar power, geothermal and hydro-electric power can offset a lot of CO2 by displacing coal power, oil and natural gas.

5. CO2 Capture from the Air – for Fuel or Storage

Technology for CO2 capture from the air is progressing.

Carbon Sciences and others are trying to scale up CO2 conversion into fuel.

Carbon Sciences estimate that by 2030, using just 25% of the CO2 produced by the coal industry, they can produce enough fuel to satisfy 30% of the global fuel demand.

The company’s plan for 2009 includes the following:

* Develop a functional prototype of its breakthrough CO2 to fuel technology in Q1 2009. This prototype is expected to transform a stream of CO2 gas into a liquid fuel that is: (i) combustible, and (ii) usable in certain vehicles.
* Enhance the prototype to demonstrate a full range of cost effective process innovations to transform CO2 into fuel.
* Begin development of a complete mini-pilot system to demonstrate the company’s CO2 technology on a larger scale.
* Prepare for the development of a full pilot system with strategic partners sometime in late 2010 or 2011.

CO2-to-Carbonate technology combines CO2 with industrial waste minerals and transforms them into a high value chemical compound, calcium carbonate, used in applications such as paper production, pharmaceuticals and plastics. This is also bordering the various using CO2 as part of cement.

Geoengineering proposals compared.

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