Carbon capture and storage

CO2 capture and storage ( technical terms: CO2 sequestration and CCS ( engl. Carbon Dioxide Capture and Storage) ) describes some large-scale projects with the goal of reducing CO2 emissions into the atmosphere by the technical spin-off at the power plant and storage in underground deposits.

CO2 acts as a greenhouse gas in the atmosphere and is the main cause of global warming. The field of application of CO2 capture and storage should be large point sources of CO2, mainly in power plants using fossil fuels, but also in industrial processes and mining. The process steps are the capture, transport (if required) and the geological storage of CO2. Right now the CO2 capture and storage in power plants still in development and pilot stages. A large-scale use in power plants appear no earlier than around 2020. In the processing and storage of natural gas, there are, however, a large scale CCS projects realized.

As a possible CO2 storage in particular geological formations such as depleted oil and gas reservoirs and deep saline water-bearing aquifers are ( aquifers ). Also a storage in the deep ocean is not excluded.

• 4.1 International Maritime Law
• 4.2 EU law
• 4.3 CCS law in Germany
• 4.4 Other Countries

• 5.1 Advantages and opportunities
• 5.2 Usability of the art
• 5.3 Storage of carbon dioxide
• 5.4 alternatives 5.4.1 Biological sequestration

• 5.6.1 coal and wind power complement poorly
• 5.6.2 deposits should not be used for coal power plants
• 5.6.3 Preference for CCS problematic
• 5.6.4 subsidization

• 6.1 Research programs
• 6.2 Pilot Installations for the capture
• 6.3 storage sites, projects and citizen protest 6.3.1 Schleswig -Holstein
• 6.3.2 Brandenburg
• 6.3.3 Lower Saxony
• 6.3.4 Saxony -Anhalt

• 8.1 Overview of literature
• 8.2 Legislation
• 8.3 Papers

Deposition

The capture of CO2 in power plants can be done by different methods, eg after combustion in a CO2 scrubbing of the flue gas ( post-combustion ), separation for coal gasification ( CO2 reduced IGCC power plant, pre-combustion ), or combustion in an oxygen atmosphere ( oxyfuel ). All three processes are developed in parallel to each other and are realized in pilot plants. Each of the techniques has over the other specific advantages and disadvantages. It is still an open question which technique (and if any) will prevail in the large-scale deployment. Critical variables include the efficiency losses, the deposition rate (proportion of CO2 is detected), the purity of the captured CO2, further environmental effects on air, water or waste path, the costs and the inertia of the process in load following mode.

Downstream deposition in the exhaust

As a final purification step of the exhaust gas after desulfurization, a CO2 scrubber will be installed. This procedure is also called post -combustion capture ( engl. = combustion, combustion ', capture = capture '). In a coal-fired power plant with an assumed efficiency of 38 % .32 kg hard coal for the production of 1 kWh of electric current necessary arises from the approximately 0.88 kg of carbon dioxide. Main component of the exhaust gas is the nitrogen contained in the atmosphere, which does not participate in the combustion. The partial pressure of CO2 is about 15%. This makes washing process relatively complex, since the nitrogen must be towed through the entire process as a kind of "ballast".

Various washing procedures are being tested. Here, too, is still open, the method will prevail for large-scale use. In the natural gas processing (but not in power plants ) on a large scale is known that amine scrubbing. The amine scrubbing the CO2 is at 27 ° C to the carrier, finely divided amine droplets attached. In a second step, the amines enter into a separator ( stripper), where the CO2 is re-emit at 150 ° C in concentrated form and then carry out the process. Amines are considered the third most common cause of job- related cancers, so this deposition would entail for workers and people with significant risks. These emissions are at using nonvolatile amines such as not to be expected of the amino acid proline or sarcosine.

Analog does a carbonate wash with bicarbonate. When the addition is carried out Carbonatwäsche at about 40 ° C and the cleavage at 105 ° C. With organic solvents, the carbon dioxide can be removed from the flue gas, such as Methanol ( Rectisolwäsche ), N -methyl-2 -pyrrolidone ( Purisolwäsche ) or polyethylene glycol ( Selexol scrubbing ). The deposition rate is with this method is up to about 95%.

Other separation methods are membrane filters, chilled ammonia or the carbonate loop process ( or lime -loop CO2 reduction process). In this method, lime is used as the circulating medium for the process. Is found in accordance with the process, the two calcium compounds CaCO3 and CaO. Since the process takes place in a temperature range of 650-900 ° C, the entire process input can be used for electricity production. This results in a relatively low loss of efficiency.

Common to all the washing processes is the high energy consumption, which is necessary for example for the regeneration of the washing agent. In a coal-fired power plant thereby decreases the overall efficiency by an estimated 8 to 12 percentage points; a corresponding increase in the use of fuel. A modern coal power plant has an efficiency of about 45%, by the CO2 capture efficiency drops to about 33-37 % then, but this still means an increase of up to about 35% of coal consumption for the same power output. None of these deposition has so far shown a CO2 deposition rate of over 90% on a large scale. Divorce Existing systems either dramatically lower levels of CO2 from, or are still in the testing and development phase.

Due to future technical innovations somewhat lower efficiency losses are expected. Currently, several test facilities are operated worldwide, in Germany at the TU Darmstadt.

For chemical syntheses, it seems energetically sense the carbon dioxide with carbon monoxide to convert ( Boudouard equilibrium). For methanol production would require additional hydrogen.

Separation in IGCC combined cycle power plants

In combined cycle power plants with integrated coal gasification (Integrated Gasification Combined Cycle, IGCC) and CO2 separation (Carbon Dioxide Capture and Storage, CCS), coal reacts in a first step ( gasification, partial oxidation ) of stoichiometry with water to form hydrogen and carbon monoxide.

With the help of suitable catalysts, carbon monoxide and water vapor can react to form carbon dioxide and hydrogen ( water gas shift reaction). Characterized a gas mixture is obtained which consists mainly of hydrogen and carbon dioxide. Due to the gasification at pressures up to 60 bar, a high CO2 concentration and thus a high CO2 partial pressure can be adjusted in the gas mixture. Under these conditions, CO2 can be absorbed with proven methods from the gas mixture ( physical absorption ). This process is called pre -combustion capture, since the CO2 is removed before combustion. The desulfurization is carried out according to the same principle ( separation of hydrogen sulfide ). The conditioned fuel gas is then mainly of hydrogen (up to 90 volume percent possible) and can be used in a combined cycle process. For this, it is still the development of a hydrogen turbine necessary, which is not yet commercially available today. Since IGCC power plants already struggling without CO2 capture with technical problems, it will take to market this technology for several years. According to calculations, this variant of CO2 capture has the least efficiency loss (less than ten percentage points). A pilot plant was established in 2011 in the Dutch power plant Buggenum.

Separation in oxyfuel process

In the oxyfuel process, the coal is burned in an atmosphere of pure oxygen and CO2 ( recirculating flue gas ). The resulting flue gas is not diluted with air, nitrogen, and consists essentially of CO2 and water vapor. The water vapor may be condensed with little effort, so that a highly concentrated CO2 stream remains (concentration ideally close to 100 percent). The CO2 can then be compressed and transported to the camp. After successful testing in a pilot plant, a pilot plant for CO2 sequestration with a thermal capacity of 30 MW in Schwarze Pumpe industrial park was taken close to the Schwarze Pumpe power plant into operation in September 2008.

Also in the oxyfuel process, the electrical efficiency compared to a plant without CO2 capture is reduced by about 10 percentage points, which corresponds, depending on efficiency of the underlying process to a 30-50 % increase in coal demand. Main power consumers is in this case the air separation unit for the production of pure oxygen.

Deposition in industrial processes

The easiest way to CO2 in plants that separate CO2 from natural gas deposit, because it occurs there in a very pure form. Initial attempts to CO2 sequestration are therefore applied to this area and not on coal-fired power plants, such as in the Algerian In Salah.

In the Sleipner gas field in the Norwegian sector of the North Sea approximately 1 million tons of CO2 per year since 1996 separated and injected in the gas field Snøhvit in the Norwegian Barents Sea since 2008 annually 700,000 tons of well .. In Sleipner, the pressure does not rise, and 24 % of the compressed CO2 are untraceable. For this, a recent study with methods untraceable fracture of 3 km in length, up to 200 m deep and 10 m wide has appeared in only 24 km away. In Snøhvit the injection of CO2 had to be stopped because the pressure rise so much that the overburden threatened to tear.

Due to the increasing demand for oil, coal liquefaction for the production of hydrocarbons for fuel purposes is profitable. This involves large amounts of CO2 because the carbon atom bound per amount of energy in the product ( hydrocarbon ) is substantially larger than in the raw material (coal). In the process, ie primary energy must be transmitted. A portion of the carbon is enhanced energy ( reduced), oxidized, another to release energy.

Other programs explore ways to filter the carbon dioxide directly by chemical absorber from the air.

" CCS -ready "

In connection with the construction of new coal power plants increasingly the terms " CCS -ready " or "capture -ready " are used that will identify that the new power plant for subsequent installations is prepared for the deposition. However, these terms are not secured by law or precisely defined. TÜV North has defined as an independent testing organization its own standard and awards based thereon a certificate.

As for the construction of the separation surfaces are required, corresponding to more than half the original power plant area, at least these areas should be released and available for use in a power plant construction or a renovation. A new power plant without these conditions can not claim to be " CCS -ready " normally.

Furthermore, the access to a camp should be given either directly at the power plant site or via long-range transport and the proof actually existing storage capacity to be provided.

Storage ( sequestration, storage)

Most researchers in the field of CO2 sequestration favor a storage in deep sediment layers, whose pores are filled with salt water. From about 800 m depth occur pressures at which the injected CO2 is compressed so that it remains in the supercritical state. In order for a re- outcrop of the carbon dioxide is practically impossible, these layers must be covered by an impermeable outer layer. Due to the prevailing pressure, the CO2 has a density about as large as the salt water, which can suppress this from the pores and allow room for the compressed CO2 is created. Where the displaced salt water remains, is one of the critical issues of CCS technology. It is mainly to the side ( lateral) are displaced and then in geological fault zones, even in the distance, rising up from the injection site and groundwater (drinking water) reach. The lateral extension of the pressure anomaly may be many times greater than the spread of the CO2 in an aquifer. If the injection of CO2 and to the displacement of salt water pressures used are significantly higher than the formation pressure and the tension of the rock, as induced earthquakes can occur which can lead to shocks in individual cases that are above the Fühlbarkeitsgrenze.

The use of deep aquifers sequestration is, however, in competition with other uses, such as the use of these aquifers for sustainable power generation from geothermal energy. Questions the environmental impact of disposal of large quantities of CO2 in aquifers have not yet been studied. The storage capacity of aquifers is limited. The suspected about 20 billion tonnes of storage capacity on German territory correspond approximately to the CO2 emissions of the German power plants for 30 to 60 years. The experience with these rock layers in Sleipner and Snøhvit show that the actual available storage capacity required to be reported significantly lower. As the EU prescribes a discrimination-free access right of all EU countries in these disposal sites, should also CO2 must be disposed of in other Member countries in Germany. Since in Germany the landfilling of waste is not permitted, even legal issues still to be resolved.

Carbon dioxide can be stored in the form of carbonates, which could also be deposited openly and without safety concerns. Suitable starting materials for this purpose primarily silicates of the alkaline earth metals. These can be personalized with dissolved carbonic acid exothermically convert to carbonates and silicas. Particularly promising are non- polymerized or low - polymerized silicates such as olivine, pyroxene and Pyroxenoide, such as Forsterite, monticellite, wollastonite, diopside or enstatite, less contrast, layer - silicates, such as the Serpentine. Nevertheless problematic is the slow rate of reaction. To landfills products would be magnesium or calcium carbonate and precipitated from the silica silicon dioxide. Researchers at New York's Columbia University under Professor Klaus Lackner showed in 2008 that of peridotite, a rock composed of olivine and pyroxene, in situ significantly faster carbonation can proceed as previously thought. This is also a technical use in situ appears to be possible, which would save dismantling and disposal. The researchers keep up with the sinking of a larger number of wells, hydraulic fracturing of the rock and an initial heating of the reactive CO2 sequestration in greater depth, where in any case prevail higher pressures and temperatures, on a large scale possible.

One can inject carbon dioxide in deep, non-degradable coal seams. The advantage of this method is that the CO2 is sorbed on the coal ( by weak physical interactions fixed). The normally contained in the coal -called coalbed methane methane is displaced thereby, and can be promoted as a relatively clean energy source and used.

Since 2008, the exchange of methane hydrates is investigated in sediments on the seabed against CO2. The commercial mining of gas hydrate deposits purpose of recovering the fossil fuel has been implemented only in a West Siberian permafrost deposits. In Japan, the USA, Canada, South Korea, China, India and other countries, however, extensive support programs are launched, aiming to start in about ten years, with the large-scale degradation of submarine hydrate. The research project SUGAR (Project ) aims to exchange the seabed methane taken against CO2.

Hazards

The CO2 can outgas and generate Kaltwassergeysire with the existing groundwater. This happens in Germany continuously, as in the Eifel in Andernach and in Wallenborn. There Geysirform this is a tourist attraction. These can be local underground solve some significant quantities of toxic heavy metals from the rocks and these so enter into the regional groundwater. In addition to the displacement of salt water from the Verpressungshorizonten in aquifers would be in addition to expect a heavy metal contamination in drinking water.

According to a study conducted at Stanford University study consists in the injection of carbon dioxide into the ground a large probability of weak earthquakes in the storage area. This would indeed too weak to cause major damage to the surface, but underground storage could be leaking through the resulting cracks and thus escape the stored carbon dioxide back into the atmosphere. Due to this fact, the converted on a large scale Kohlenstoffdioxidspeicherung is considered in the study as a risky and likely unsuccessful strategy of reducing greenhouse gases. Since incur for capture, transport and injection of CO2 substantial amounts of additional CO2 emissions, could the CO2 content of the air by CCS even rise significantly within 100 years in case of leakage rates of only 1% per year.

Legal framework

The technology chain of CO2 sequestration touches a variety of legal areas from pollution control through the civil protection to the mountain and water law. However, none of these laws describe the new activities of the CO2 sequestration sufficiently so that in many countries, legislative activities have been started. Legal systems, which have no freedom of mountain natural resources must also clarify the legal relationship between CO2 storage and the overlying land.

Mining law, in Germany the Mining Act is generally applicable only if CO2 sequestration is used for example in the context of traditional mining activities for the promotion of oil or gas.

International Maritime Law

The ban on the shipment of waste at sea ( dumping ) and the ban on exports of waste for shipment into the sea, which are laid down in the London Convention of 1972 and the OSPAR Convention, also relates to the storage of CO2 in the sea or under the seabed. As the world's first CO2 storage project was implemented in the Norwegian offshore oil platform Sleipner, there was a need for regulation here. The States Parties to the OSPAR Convention in 2007 adjustments decided permitted at the London Convention 2008. Accordingly, the disposal of CO2 in geological formations under the seabed. The hitherto (and in some countries today ) discussed shipments of CO2 into the open water column is the respective Contracting States, however, has since prohibited.

EU law

At EU level, Directive 2009/31/EC regulates the geological storage of carbon dioxide, the selection, approval procedures and operation of CO2 storage. This Directive is since June 25, 2009 and provides, inter alia, the procedure for the approval process in the exploration, operation and closure of CO2 storage and are substantive standards to the nature of the geological formations.

Further requirements such as the mandatory use of CCS in new power plants and retrofitting Existing were in the discussion, but are not included in the directive.

The EU Directive does not apply directly in Member States. These have to implement the Directive into national law. To this end, Member States had a period of two years, ie until 25 June 2011. According to the EU Commission's Communication have 25 of the 27 Member States, this deadline is not met. Only Spain and Romania have reported completion on schedule. The EU - Commission to consider the European Treaties sanctions against the defaulting States.

CCS law in Germany

In Germany the use of CCS since August 24, 2012 by the Law on Demonstration of permanent storage of carbon dioxide ( carbon dioxide storage law - KSPG ) is regulated by law. Germany has therefore also the EU Directive 2009/31/EC into national law. The law provides for a maximum amount of memory for Germany of four million tons of CO2 per year in total and 1.3 million tons per year per store, and a clause states that individual states should enable the option on the general prohibition of storage of CO2 in their territory.

The previous two attempts were the federal government to adopt a carbon dioxide storage law. A first attempt of the grand coalition to adopt a CO2 storage law failed in June 2009 before the end of the 16th Parliament. This also significant protests in the population have contributed. In Schleswig -Holstein the discussion of the bill coincided with a period of massive protests against a CO2 storage project and the campaign for the parliamentary elections in the fall of 2009.

Since both the 2009 parliamentary elections as well as the Schleswig-Holstein state election resulted in yellow and black majorities, but these in Berlin and Kiel representing opposing positions for CO2 storage, the re- presentation of a CO2 storage law lasted until April 2011. The new bill had criticism apprehended at the old design and lifted by stronger temporal and quantitative limits the demonstration character. Furthermore, it contained at the instigation of Schleswig- Holstein and Lower Saxony countries a clause that would allow states the option to the general prohibition of storage of CO2 in their territory. This bill failed in September 2011 in the Bundesrat. The federal government then appealed to the mediation committee. After months of negotiations, an agreement was reached on the basis of the Bundestag and Bundesrat adopted the law end of June 2012. It came a day after the publication in the Federal Law Gazette Jg 2012 Part I No. 38 in force.

The CO2 test memory Ketzin is approved by mining law. Also, further investigation permits for exploration of CO2 storage has been filed before the entry into force of the KSPG (for lack of an appropriate legal framework ) to mining law ( " exploration of Sole" ) and could be transferred to exploration licenses according to the KSPG. However, there was at the time of entry into force of the KSPG no open application procedure.

In a 2012 position paper published the energy supplier EnBW criticized the CCS technology. At present, there is no acceptance in the population for the underground storage of CO2 and also " CCS is associated with considerable costs in perspective, the production costs of renewables including PV significantly exceeds ". In addition, EnBW known to the energy revolution and saw the systematic and economic benefits of renewables, which applies expand it now.

Other countries

In the EU, other countries want, for example, the Netherlands and the UK, to implement the EU Directive in a timely manner and discuss appropriate legislation. In Austria, the CO2 disposal was prohibited. Only research projects up to 100,000 tonnes of CO2 were allowed.

In Australia, a new law regulates the storage of CO2 offshore in territorial waters. For storage on land, there are some states regulations. Similarly, the CO2 storage is regulated by individual states in the United States and Canada. A nation- wide regulation is located in the United States currently in the public hearing.

Assessment

Benefits and opportunities

Since rapidly increasing use of renewable energy and increased energy efficiency on the production and consumption side will replace even under optimistic assumptions fossil energy only in the long term, the global electricity supply nor for decades - especially in the growth markets of China and India - have to rely on fossil primary energy sources. It is constructed with durable storage ( disposal ) of carbon dioxide therefore possibly a way to reduce the otherwise expected rising pollution of the atmosphere with greenhouse gases.

In sediment layers intercalated carbon dioxide would also ( locally limited and in the amount of no significance ) its advantages: In almost depleted oil reservoirs could thus increase the delivery pressure. Such programs are already underway in the UK ( North Sea) and the USA. This technique is called EOR (enhanced oil recovery ). For this to be considered as comparable risks for CCS.

Substituting biomass as a fuel is a, you could withdraw in conjunction with CCS CO2 from the atmospheric circulation. This is caused by human activity CO2 emissions could even remove it from the atmosphere.

The main technical work of CCS technology ( flue gas desulfurization ) is also a prerequisite for wind gas. With this option, CO2 is converted by hydrogen from unsteady flow available to speicherfähigem and delayed usable methane.

Usefulness of the technique

The loss of efficiency at the power plant operates at the current state of the art to a loss in efficiency of power plants by about 10 percentage points. This corresponds to an increase of about 30% of resources. Hence in addition to high costs resulting a faster consumption partly already scarce resources and reducing environmental loads by destruction of the countryside ( eg in the case of brown coal mining ), the transport, the increase in heat and the emission of other pollutants ( particulate matter, heavy metals). Other environmental consequences caused by increased production of wastewater and waste as a result of the deposition process. These can not yet be quantified with the current state of knowledge.

In any case, the technique would increase electricity from coal-fired power plants significantly.

In pipeline lengths of more than 500 km, the losses are likely to be higher. For Europe, a CO2 pipeline network of 22000-37000 km length is planned. Taking the experience from the USA to reason would be to reckon with six leaks each year with a 25,000 km long pipeline network. Not included is the long-term use of energy, as in the deposits over thousands of years monitoring should take place. This raises the question of whether the energy balance of CCS power plants at all positive.

In addition, must be seen that the technique is not a CO2-free, but a CO2 "poor " current production allows. There are actually avoided only about 70 % of CO2 emissions.

Storage of carbon dioxide

The storage of carbon dioxide is currently being discussed, especially in deep saline aquifers (salt- water-bearing underground layer ) and disused oil and gas reservoirs. According to the Federal Institute for Geosciences and Natural Resources are the capacities of these at about 20 billion tonnes ( saline aquifers, accumulated) or 2.75 billion tonnes ( disused oil and gas deposits, accumulated). This capacity would be sufficient to store the emissions of all German power plants for about 30-60 years. So it is not a long term solution, after about a generation of power plants storability German underground storage would be depleted. This could be the short-to medium-term objectives correspond to which the technology is designed.

For some types of storage, particularly at the discharge into the sea, the stored CO2 could reach in the course of some 100 to 1000 years back into the atmosphere, so that only reaches a delay of emission or in extreme cases even to an increase in CO2 would come emission ( due to the increased fuel use more CO2 is produced than without separation ). Also in some underground storage, which in principle are far more reliable, the tightness of the repository is difficult to assess. The monitoring of CO2 storage is therefore important object of development. The risk of gradual outgassing, which would negate the climate effect of CO2 sequestration might go unnoticed, also complicates the search for appropriate sites, for the final fate of the gas must of course be backed up ( for at least 200 or 10,000 years depending on the view). The German Federal Government considers from a climate policy perspective, a maximum leakage rate of 0.01 % per year is acceptable, in the years after 1000 for about 90 % of the CO2 remains in the repository.

When storing very large amounts of CO2, the salt water is displaced from the aquifers. Since this can not avoid " down ", it will flow to the side and ultimately to weakness zones of the mountains ( fault zones ) to ascend, so that it can then come to mixing with the groundwater. However Secure storage locations have the requirement, sufficiently far from fault zones that have such a high permeability up to the surface to be removed. Since there are, according to the BGR alone in Lower Saxony over 16,000 deep wells, cracks and fractures to the planned storage horizons, bringing the total number of possible reduced CO2 disposal once again.

Far more dangerous than the gradual outgassing of stored carbon dioxide would be a sudden outcropping. This high CO2 concentrations would be reached, the cause asphyxiation (see Nyos disaster ). Based on observations in natural gas production, the occurrence of earthquakes in the area of ​​deposit and thus possibly one such outcropping through cracks or broken drill holes can not be excluded. However, with the known borehole accidents, the release rate is significantly lower (dot manner, no large water surface ), and thus the expected concentrations in the air is less.

The introduction of large amounts of CO2 into the sea can have massive environmental impacts, for example by lowering the pH or the formation of " CO2 lakes " on the seabed, which kill life there (see also carbon cycle, above all, problems of technical solutions ).

The processes for CO2 sequestration lead to additional costs of electricity generation. The economic feasibility, therefore, depends largely on the conditions laid down in the CO2 trading prices of emission rights. The aim of the European emissions trading scheme is to promote CO2 - reducing technologies, including CO2 sequestration heard. Since the CO2 sequestration is expected in 2020 are industrially available, arises from the cost side in addition the extent to which the technology still can compete with renewable energy. Renewables is said a large cost reduction potential, the CCS technology will lead to a significant increase in the cost of electricity production from fossil fuels. Several research institutes have to carried out a study commissioned by the Ministry of Environment, which has the result that electricity from offshore wind turbines could be cheaper as early as 2020 as electricity from fossil fuel power plants with CO2 sequestration.

Alternatives

Critics of CO2 sequestration argue that other alternatives with fewer problems afflicted, developed and at least be cheaper in the long term. In particular, be mentioned here:

• Measures for saving energy and improving energy efficiency
• Development of renewable energies
• Increased use of nuclear energy
• Biological sequestration.
• Recycling by methanation

Biological sequestration

The previous research or projects dealing generally with only the storage of liquid or gaseous CO2 or in the form of dry ice. In addition, there is also the possibility to store the CO2 to bind as biomass and derived therefrom as carbon, eg as pyrogenic carbon in the form of biochar or black earth (see Terra preta: black soil in Amazonia ). This aggregate form most of the above criticisms are no longer applicable. This detour, however, shows that it would be most effective to leave the fossil carbon deposits are the same unaffected, rather than later restore.

Another possible sequestration offers afforestation, according to the German Chemical Society ( May 2004) to realize meaningful and much cheaper than was the separation of CO2 from flue gases. However, CO2 is only permanently bound when the wood produced is not burned or rotted away, but is built to houses or furniture. Wood is a storable -bound form of carbon, from a compressed and protected from rotting storage form could be produced. Effect would also be the rewetting of peatlands, as here by the nursery of peat moss in addition resulting peat carbon can be bound. By rewetting it comes to air seal, which prevents the degradation of organic matter and thus the re- release of CO2. Often such measures also benefit other environmental protection objectives.

Individuals can perform the CO2 sequestration through afforestation.

Furthermore, the fertilization of sea areas is currently being explored with iron. So that the growth of algae to be conveyed. These bind like plants on land CO2 sink then ideally to the ocean floor and remain there. However, the impact on the resulting strongly influenced ecosystems are largely unknown and it is unclear how much CO2 is actually permanently removed from the atmosphere by this method. Currently, the Alfred Wegener Institute conducts the experiment LOHAFEX (see also EisenEx ) to gain insights on these issues.

Costs

The cost of CO2 sequestration shall consist of:

• Capital cost of the capture plants
• Operating costs of the capture plants
• Cost of the additional fuel consumption due to the reduced efficiency of the power plants
• Cost of transport to the bearings
• Costs for storage, including monitoring.
• Returns for civil protection and the defense of claims.

The height has not yet been known. The Global CCS Institute estimates that the cost currently lie at 23 to $ 92 per tonne of CO2 and sink through future research and development work can continue, since the prices of CO2 allowances to be seen in the EU in the long term over 20 euros, can thus CCS achieve profitability. Provided is here, however, that other alternatives (eg renewable energy ) are not sufficient or only at higher cost.

Criticism of the Environmental Council

The draft law on CCS met in May 2009 to sharply criticized the Advisory Council on the Environment. Recommended is a research law for a limited number of demonstration projects instead. The paper warns strongly against risks and hidden costs and mentions the following points:

• Risks are still unexplored. The bill would allow CCS but the same large scale. The storage is irreversible.
• To date, there is no acid-resistant concrete to seal the boreholes can. It threatens another uncontrollable disposal problem.
• Eternity costs over several 1000 years of taxpayers' money, as energy companies pass the deposits to the federal government 30 years after decommissioning. This then carries the risk of liability and the monitoring costs.
• Use conflicts with geothermal energy and compressed air storage for wind power. CCS would by the law in effect takes precedence.
• Bill is premature since 2020 by CCS, no significant contribution, it should be expected.
• Indirect promotion of coal-fired power through free access to limited resources of memory
• High direct subsidies for CCS for energy companies at the expense of renewable energy
• Lack of land / influence locally
• Important details not regulated
• Underestimated acceptance problems

In addition, the Environmental Council expresses criticism of CCS in conjunction with coal-fired power:

• Cleavage, transport and storage decrease the efficiency of the power plants
• Technology would be available only after immense investments available

Coal and wind power complement each other badly

In general, the Environment rated the handling of CCS as a " course for the German energy and climate policy." Thus, the construction of new coal-fired power plants is only compatible with climate protection targets, if CCS is installed. Coal and nuclear power, however, apply to be unsuitable to flexibly add to the growing amounts of wind and solar energy. When changing wind conditions such base load power plants are eg not in a position to quickly runterzufahren high or. A high proportion of wind and solar energy would have a negative impact on the economics of coal-fired power plants. This is the goal influential energy companies would therefore have no interest. Conclusion According to Environment: " A high proportion of base load power plants can stand the further expansion of renewable energies in the way. "

Gas or hydro power plants, however, can react faster and are better according to the supplement.

The discussion leads to the question whether it is possible to dispense with full security of supply on new coal-fired power plants. The Environment here clearly positions itself: " The system decision should be made in favor of renewable energies. "

Deposits should not be used for coal power plants

The Environmental Council rejects CCS not on principle. Instead of the deposits, however, use up coal-fired power plants, CO2 should be actively removed by biomass at a later time the atmosphere instead. This might be necessary in the second half of the 21st century in order to keep climate change in check.

Favor of CCS problematic

The law gives companies after investigation a right to use the resource base permanently. Private property rights or planning jurisdictions of municipalities, counties and states will no longer play a role. The authorities would be forced to approve: For the course I'm the one who " makes an application first". Thus, CCS is clearly toward future alternative energy sources such as geothermal energy and compressed air storage favors the Environment Council considers that, since they no longer would qualify.

Subsidization

• The opinion puts the research funds of the current programs in the EU to 745 million euros.
• The Recovery Plan of the EU in March 2009, thus further 1.05 billion euros are provided.
• There would also be an estimated 9 billion euros through carbon credits, which were reserved specifically for CCS by 2015.
• State aid for environmental protection could also flow into CCS projects.
• The European Investment Bank is to 1 billion euros in loans, among others provide for CCS funding.

Conclusion of the opinion: " The companies incurred additional costs (...) could - depending on the price of emission allowances - are largely to completely covered by the planned support at EU level." It is necessary to examine " how the subsidization of CCS affects the competitiveness of other climate protection technologies ."

Implementation

Research programs

In many industrialized countries of the world CO2 sequestration is explored. The European Union has increased its recent research budget for this range from 30 to 200 million euros. As part of the European Energy Programme for Recovery 2009 funding commitments over 1 billion euros for CCS projects were given. Already exists in the United States since 1997, such a research program.

In the Federal Republic of Germany is examined Geotechnologies and Cooretec in research projects under the programs, how the necessary power plant in Germany from 40 GW ( about 1 /3 of the maximum capacity of all German power plants) should be designed so that the necessary reduction of CO2 emissions achieved can be. In particular, the efficiencies of the power plants have to be maximized, because as the CO2 attack is minimized at source. Furthermore, we tested the implementation of power plant technologies with CO2 capture (forecast: first use until 2030) as well as ways to separate the gas from the flue gases of conventional power plants. Finally, the captured CO2 is looking for ways to store permanently and safely.

In September 2009, the Federal Ministry of Education and Research ( BMBF) has stopped the funding of a project to investigate memory locations.

At EU level, the technology platform for CO2-free power plants (TP ZEFFPP ) was established, which examines the state of research in international cooperation of experts from non-governmental organizations, academia and industry and determine the need for action to implement the vision of CO2-free power plants. This committee also prepares proposals for the alignment of the 7th EU Research Framework Programme. However, It should be noted that the term CO2 - free power plants is misleading, it is at best a reduction of CO2 release to the atmosphere. This is especially true if not only the plant, but the generation of electricity from coal is considered as a whole.

Pilot plants for the separation

Currently in different systems, the CO2 capture in power plants tested at pilot scale:

• Black in the power plant pump by Alstom and Vattenfall Europe
• Staudinger power plant by Siemens Energy and E.ON
• In the power plant Niederaußem by RWE, Linde and BASF
• In the power plant Heilbronn EnBW through practice tests for amine scrubbing process.

Storage sites, projects and citizen protest

The potential storage capacity for CO2 / accepted for the Federal Republic of Germany with about 12 billion tons ( gigatons = ) CO2 plus minus 3 billion tons. These figures are largely based on estimates and have changed significantly in the past, usually downwards. Extensive studies on this can be found at the Federal Institute for Geosciences and Natural Resources ( BGR).

Schleswig-Holstein

The power company RWE had between 2006 and 2010 plans followed to install CO2 capture to a new lignite-fired power plant on the site of the gold mine in Hürth and to pump this CO2 over a 530 km long pipeline to the northern Schleswig -Holstein, and to press there. Originally, the plant should be operational by 2015.

Schleswig -Holstein's Environment Minister Christian von Boetticher, Economy Minister Dietrich oyster man ( both CDU ) and RWE Dea had the "common project" first with a " go-ahead " announced. First was roughly from North Frisia and East Holstein as a storage region of the question. In May 2009, the country's economy ministry had approved soil testing in both regions. RWE Dea first started in Südtondern / Schafflund about 20 times in a 15 km region in the offices Südtondern, Mid North Friesland and Schafflund.

In late May and early June 2009, RWE Dea, the project then the first time the mayors of the affected municipalities in detail before. There were plans for more 1000 underground explosions for seismic testing to determine the geological formations. The plans meet with strong resistance in resort. The citizens' initiative against the CO2 repository eV in Schleswig -Holstein had more than 80,000 signatures on a petition collected by its own account from May to November 2009 written regular demonstrations, stickers and posters and organized human chains. Agencies and local councils organized in the summer of 2009, numerous well-attended information sessions on which RWE -DEA presented the project and various speakers from research, government and environmental organizations discussed controversially.

Country - SPD, SSW, Greens and the Left Party had spoken in Schleswig -Holstein early against the project. In June and July 2009, followed by numerous unanimously adopted resolutions of district assemblies, communities and associations. The cross-party protest on site meant that the Schleswig- Holstein CDU umschwenkte and the project did not want to continue to push forward. The FDP relented. Thus, the Schleswig -Holstein Landtag 17 June 2009 decided unanimously to reject the storage projects and reject the CCS law in the Bundesrat. After the regional elections of 2009, the state government reiterated its negative stance. RWE then took of his plans distance and put the entire CCS project on ice.

Brandenburg

In Brandenburg, the energy company Vattenfall CO2 wanted to split off on a new block of lignite power plant in Jaenschwalde, transport via pipelines and compress Beeskow ( Oder-Spree district ) or Neutrebbin ( Mark- district or country) in the subsurface. For this project, funds from the EU amounting to 180 million euros were provided have been the response to the project was split in the country. While the state government, trade and craft chamber and parts of unions such as the IGBCE supportive of the project, it was above all in the announced memory regions rejection. Against the project, the citizens' initiatives CO2ntraEndlager and CO2 repository - stop eV more than 10,000 signatures were collected. Political support to get the Brandenburg citizens' initiatives by the CDU Bundestag Hans -Georg von der Marwitz from Mark- or country who sees economic and environmental aberration in CCS. Similarly, the Evangelical Church of Berlin -Brandenburg -Silesian Upper Lusatia has ( EKBO ) expressed in a decision of the Synod on 30 October 2010 as a result of unknown risks against the testing of CCS in Brandenburg. The left is divided into the CCS question: while individual voices CCS reject, is the Brandenburg state party and, in particular Economics Minister Christoffer for coalition agreement with the SPD, in which it supports CCS, although the left before the 2009 election campaign with the slogan " Consistently against CO2 had campaigned repository ".

After the State Office for Mining, Geology and Minerals of Brandenburg ( LBGR ) had granted the exploration permit for exploring the region Birkholz - Beeskow and Neutrebbin 2009, Vattenfall had been prompted operating plans for the exploration ( seismic, drilling) to set up and re-approved. To this end, it did not come. In December 2011, Vattenfall presented the project having regard to the delay in the legislative process for carbon dioxide storage Act ( KSPG ).

Lower Saxony

According to press reports had submitted applications for the exploration of brine in the counties Wesermarsch and Cuxhaven and other counties in connection with power plant plans in Wilhelmshaven in June 2009, E.ON Gas Storage GmbH (EGS ). E.ON did not pursue the project after 2010.

The Danish company Dong Energy in 2009 thought about it to use for a new coal-fired power plant in Emden CCS. A deposit has not been named.

Saxony-Anhalt

In the winter field / Mahlsdorf district Salzwedel, the company GDF Suez wants to try m³ together with Vattenfall in the almost empty subsidized natural gas subfield Altensalzwedel the storage of carbon dioxide in connection with the promotion of the remaining natural gas amounting to 2 billion.