Carbon capture and storage technology explains what is "carbon capture and storage technology" according to the context.

20 1 165438 On February 7th, the United Nations Climate Change Conference in Copenhagen ended as scheduled, and representatives from 192 countries and regions attended the meeting. After talking for a few days at the hot conference, it seems that the conference has turned into a quarrel.

Although the national emission reduction goal is a tug-of-war, how to achieve these emission reduction goals will be a concern of the country in the future, so carbon capture technology has once again become the focus of media attention.

Technical illusions, such as artificial volcanoes or space mirrors, are unreliable. Compared with carbon dioxide capture, CCS is considered to have saved the planet. We all know that human beings should prevent global warming, save energy and reduce emissions, especially reduce carbon dioxide emissions. Emission reduction path, but coal is the main energy source, reducing the cost of coal use is high. For those countries that don't want to change the energy consumption structure, CCS has become an important substitute and very attractive.

People may feel a little strange about carbon capture technology and don't know it. "One of the most cutting-edge and important topics in the field of climate change in the world today, international politicians have paid great attention." At the end of last year, Zhou Xiaochuan, governor of the central bank, talked about the meaning of "carbon capture". In this regard, the financial industry has great potential. According to experts' opinions, in Zhejiang University, many foreign research institutions have smelled the great temptation and quietly targeted the domestic carbon emission market.

The concentration of carbon dioxide in the primitive atmosphere is very high, which is not suitable for human survival. The earth solidified the buried carbon dioxide (that is, coal turned into oil), which reduced the concentration of carbon dioxide in the atmosphere and made it suitable for human survival. Now, on the contrary, humans dig up oil and carbon dioxide through coal mining and release them into the atmosphere. With the increase of carbon dioxide concentration in the atmosphere, the greenhouse effect has a series of effects.

In reality, this is a satire on the industrial revolution, the crazy use of fossil energy and revenge. The post-industrial era is an industrial revolution destined to solve these troubles.

1850, the global carbon dioxide emissions were only 2 million tons, and increased to 259 million tons in 2005. Among them, the global consumption of fossil fuels is mainly concentrated in carbon dioxide emissions from industry, electricity and transportation sectors, accounting for about 63.09% to 72.96% of the total global carbon dioxide emissions.

Now, world leaders hope that in 2050, climate control will not exceed 1850 degrees Celsius.

Scientists have figured out various ways to reduce carbon dioxide emissions in the atmosphere.

The first step is "carbon capture". According to Professor Wang Fang Meng Xiang's mature chemical absorption method, in short, it is to separate the chemical reaction between CO2 gas in flue gas by absorbing CO2 and certain water. Scientists have found all the above excellent properties and environmental protection absorption. Another method is called "membrane separation". When the flue gas produced by the combustion of fossil fuels passes through the membrane, part of it will be dissolved, but part of it will pass through the block. In order to improve the efficiency of carbon dioxide emission, scientists have also invented a flame cutting method using pure oxygen to produce high-purity carbon dioxide emission. It is reported that there are many carbon capture pilot projects in the world, including China, such as the United States, Britain and Norway, among which the carbon capture efficiency is as high as 90%.

Is carbon capture the hardest? In addition, "scientists need to preserve CO2 safely and permanently, even if the captured CO2 is recycled to produce carbonated drinks and eventually discharged into the atmosphere". This carbon capture and storage technology is called carbon for short.

Capture and storage technology.

At present, the main idea of scientists is to "seal underground, including deep sea storage and geological storage." Let me talk about "deep seawater storage". We should know that the ocean is the largest carbon dioxide reservoir in the world, with a total storage capacity of more than 50 times that of the atmosphere, which plays an important role in the global carbon cycle. The ocean storage of CO2 mainly refers to transporting CO2 from the ocean storage place to the seabed through pipelines or ships, and then injecting it into the seabed. The water at the bottom of the sea was finally carbonized and preserved. This method also has some hidden dangers: "When the CO2 ship reaches the seabed with high pressure, CO2 leakage will lead to disastrous consequences, especially frequent offshore earthquakes."

Scientists believe that the more feasible geological storage, the carbon dioxide salt water layer reaches the ground at this depth 1 km to 2 km, and the pressure converts carbon dioxide into the so-called "supercritical fluid" and the vulcanization speed is slow, like the underground coal-to-oil system. In this state, carbon dioxide is not easy to leak. "In addition, this rock mass has a good structure, which is more than enough to accommodate carbon dioxide and continuity. Is the area large enough? It is a saline water layer, and it is estimated that the global reserves will reach 10 trillion tons, and it can be stored at 1000.

So far, there have been three successful CCS projects in the world. The carbon dioxide produced by Midale landfill in Weyburn is extracted from the abandoned oil field BP in Saskatchewan, North Dakota, and the carbon dioxide in the natural gas produced by Sala oil field project in Algeria is imported from the local area into the ground. The national oil company, Norwegian oil and gas company, has two similar projects in Beihai. There are hundreds of CCS projects under construction in the world.

In China, following the Beijing Huaneng Gaobeidian project, the carbon capture project of Huaneng Shidongkou No.2 Power Plant was launched in Shanghai in July, with a total investment of 654.38+0.5 billion yuan. The project will be completed by the end of the year, and it is expected to capture 6,543,800 tons of carbon dioxide every year, making it known as the world's largest carbon capture project for coal-fired power plants.

Although CCS technology is still in the experimental stage, the technical ability and ideal effect have not been proved, but the high cost has made people speechless. According to a report published by the Massachusetts Institute of Technology last year, every ton of carbon dioxide captures and processes supercritical fluid under pressure, and the cost of transporting one ton of carbon dioxide to fill the landfill is $ 30-50 yuan 10-20, which means that the emission of one ton of carbon dioxide in the atmosphere will cost $ 40-70, and the current carbon price in the European Union is $ 8- 10 Euro/ton.

Professor Wang made a simple calculation for the reporter: For example, the carbon dioxide emission of burning one ton and two tons of coal is 600 yuan/ton now, and the increase of carbon emission exceeds that of 600 yuan, so the cost is doubled, and the electricity price of burning one ton of coal to generate 300 kWh electricity is increased by 70%-90%, and the increase of carbon in the production, transportation and sales prices of each commodity can finally calculate the commodity price of carbon emission. "The carbon tax levied is very impressive." No wonder experts say that the global carbon market has the greatest potential for oil trading, and after carbon emissions trading, it will become the largest market in the future.

At the same time, state capital has begun to covet this industry, and the European Commission has made it clear that the EU plans to directly invest 8 billion euros in CCS technology research and development. "For us, this is both a challenge and an opportunity. At present, many foreign institutions have targeted the domestic carbon emission market. For example, Zhejiang University has established technical cooperation relations with the European Union, the United States and the British Department of Energy. In fact, compared with our domestic carbon capture technology, the cost of many foreign countries is lower. If we can seize some market share, it is still very promising. Unfortunately, some domestic enterprises have a vision. Professor Wang Fang Meng Xiang (Youth Times)

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Brief introduction of carbon capture technology

Four main different types of CO2 collection and collection systems:

The mature technical characteristics of various capture technologies after combustion (flue gas separation) and before separation (hydrogen-rich gas line), oxygen-rich combustion and industrial separation (chemical cycle combustion) are shown in the following table. When choosing a capture system, carbon dioxide concentration, gas flow pressure and fuel type (solid or gas) are all important considerations.

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It is difficult to collect carbon from a large number of scattered carbon dioxide emission sources, so the main targets of carbon capture are centralized carbon dioxide emission sources such as fossil fuel power plants, steel plants, cement plants, oil refineries and synthetic ammonia plants.

There are three main types of carbon dioxide emissions captured by> separation system: combustion system, oxygen-enriched combustion system and pre-combustion system.

Introduction of combustion system

The purpose of capture and separation after combustion is to separate CO2 and N2 from flue gas. Chemical solvent absorption method is the best method for CO2 capture after combustion at present, which has high capture efficiency and selectivity, and reduces energy consumption and cost.

/& gt； Chemical absorption. In addition to chemical solvent absorption, adsorption and membrane separation, France uses the reversible chemical reaction between alkaline solution and acidic gas. Flue gas not only contains pollutants such as carbon dioxide, nitrogen, oxygen, H2O2, sulfur oxides (SOx), nitrogen oxides, dust, hydrogen chloride, hydrogen fluoride, etc., but also contains impurities, which will increase the cost of capture and separation of flue gas before it enters the absorption tower, as well as the need for pretreatment, including washing and cooling.

Flue gas pretreatment enters the absorption tower, and the temperature of the absorption tower is kept at 40? At 60℃, CO 2 is absorbed by absorbent, usually in gas with water balance system, in which the solvent is amine absorbent (such as monoethanolamine MEA) and the solvent vapor is removed. Then the flue gas is sent to the washing container, and the CO2-rich solvent after the droplets leave the absorption tower is pumped to the top of the regeneration tower through heat exchange. The temperature of regenerated absorbent is 100? Water vapor with the temperature of 140℃ and slightly higher than atmospheric pressure returns to the regeneration tower through the condenser, carbon dioxide leaves the regeneration base of the regeneration tower, and the solvent is pumped back to the absorption tower through the heat exchanger and cooler.

Oxygen-enriched combustion system

The combustion products of oxygen-enriched combustion system and pure oxygen or oxygen-enriched air instead of fossil fuels are mainly carbon dioxide and water vapor. Except that excessive oxygen ensures complete combustion and the oxidation products of fuel, fuel oil or air leak to all inert parts in the system, after the flue gas with high CO2 is cooled, the CO2 content in the steam condensate is 80%.

98%。 This high-concentration CO2 is compressed, dried and further purified for pipeline storage. When the density supercritical passes through the pipeline, it is necessary to reduce the content of inert gas to a lower value to avoid increasing, which may be due to the critical pressure of carbon dioxide flowing in the pipeline. It is characterized in that carbon dioxide needs to be removed in the transportation of acid gas components, and it is dried in the pipeline to prevent condensation and corrosion, and traditional carbon steel materials are allowed to be used.

Due to the high concentration of CO2 in oxygen-enriched combustion system, the cost of capture and separation is low, but the cost of oxygen-enriched oxygen production is high at present. Through air separation methods, including polymer membrane, pressure swing adsorption and low temperature distillation.

/& gt； Pre-combustion capture system

Pre-combustion capture system mainly has two stages of reaction.

First, fossil fuels react with oxygen or water vapor to produce a mixed gas (mainly composed of CO and H 2), which is called steam reforming reaction. The steam must be carried out at high temperature, which is called "partial oxidation" for liquid or gas fuel and O2, while the solid fuel reacts with oxygen until the synthesis gas is cooled. Then, CO in syngas is converted into so-called "partial oxidation" by steam reforming reaction. Carbon dioxide produces more H2. Finally, the dry mixture with H2, H2 and CO2 content as high as 15% ~ 60% was separated from the mixture, and the total pressure was 2? 7 MPa. CO2 is separated, captured and stored from the mixed gas, and H2 is used as the fuel of the gas combined cycle and sent to the gas turbine, gas turbine and steam turbine combined cycle for power generation.

In this process, the combined cycle of carbon capture and storage gasification (IGCC) is considered, which includes: separating CO2 and H2 from gas. Pressure swing adsorption, chemical absorption of carbon dioxide (removing carbon dioxide from mixed gas through chemical reaction, reversible reaction after heating under reduced pressure, combustion of carbon dioxide separated from flue gas, etc. ), physical adsorption (usually used to separate mixed gases with high CO2 partial pressure or total pressure), membrane separation (polymer membrane, ceramic membrane) and so on.

Carbon capture and storage technology

Carbon capture and storage (CCS) is a place to collect, transport and safely store industrial and energy CO2 emission sources, which is isolated from atmospheric processes for a long time. It is mainly composed of CCS tee, which is used for capture, transportation and storage.

Carbon capture

CO2 capture refers to the process of separating and compressing carbon dioxide from flue gas produced by fossil fuel combustion.

It is difficult to collect carbon for a large number of dispersed carbon dioxide emission sources. Carbon capture is an emission source separation system for fossil fuel power plants, steel plants, cement plants, oil refineries and ammonia plants. Capturing fossil fuel power plants is the main target of carbon dioxide concentration. There are three main types: post-combustion capture system and pre-combustion oxidation fuel capture system.

In some industrial applications, CO2 capture has been used in chemical adsorption process. In a factory in Malaysia, the flue gas flow of a single gas-fired power plant is 0.2× 106 ton CO2, which is used for urea production. The physical solvent gasification plant of coal is located in North Dakota. Every year, 3.3× 106 tons of CO2 is separated from the gas stream to produce synthetic natural gas. The project of capturing CO2 to enhance oil recovery is located in Canada.

Low-carbon traffic

The first long-distance CO2 pipeline was put into operation in the United States in the early 1970s, exceeding 2.

500 km CO2 pipeline, each pipeline is about 40× 106 tons of CO2 for improving crude oil recovery and storage.

Carbon sequestration

CO2 is transported to Texas and reaches storage sites, such as geological structures where CO2 is injected into underground salt water layers, abandoned oil and gas fields (such as coal mines), geological structures or deep seabed or below.

This process involves a lot of research, development and wide application of oil and gas exploration and production technology, such as pumping CO2 into the ground, perforating CO2 at the bottom of the well or screening it into the rock stratum.

BR/>； Besides reinjecting CO2 into the oil field to improve oil recovery, the injected CO2 can also restore coalbed methane in the coal seam. This process is often called EOR and ECBM. There are three industrial-scale projects (more than 1× 108tCO2/A) using this technology:

Carbon project, SLEIPNER project in Beihai, Weiben project in Canada and Salah project in Algeria. Introduction of transportation technology

The most feasible way to transport carbon dioxide is to use pipelines.

Pipeline is a mature market and technology. Carbon dioxide gas compression can increase the density and reduce the transportation cost. It can also be installed on an oil tanker transporting liquid carbon dioxide and use a marine carbon dioxide incubator. In some cases, it is more attractive from the economic point of view, especially for long-distance transportation or overseas transportation of CO2. However, due to limited demand, in this case, the transportation scale is small. Technically, both road and railway tank cars are feasible. But except for small-scale transportation, this kind of transportation system, pipeline and ship are not economical, and it is unlikely to be large-scale transportation at present.

The pipeline transportation technology in the United States and other countries is very mature, and the problem to be solved is how to reduce the transportation cost.

The transportation cost mainly depends on the length and diameter of the pipeline. Capture (including compression) costs are high, so transportation costs are low. As long as the cost of capture and storage is low, or in order to obtain some other benefits (such as improving oil recovery), the cost of long-distance transportation of CO2 is very high in many countries.

For example, in the United States, the long-distance transportation of high-pressure liquid CO2 improves oil recovery, and Yangshan (sheep), the longest pipeline, is used.

Mountain) pipeline, transporting CO2 from South Colorado to Permian Basin in Texas, with a distance of 656 kilometers.

Brief introduction of carbon sink technology

Carbon sink refers to the process of capturing and compressing CO2 and transporting it to designated places for long-term storage.

At present, geological storage, marine storage and manganese carbonate ore storage are mainly archived. In addition, some industrial processes capture a small amount of CO2 during production and storage.

However, the untreated flue gas discharged from ordinary power plants contains about 3% to 16% of carbon dioxide, and the compression rate is much less than pure carbon dioxide. The carbon dioxide content of compressed flue gas in coal-fired power plants is only 1 ton 15% stored.

Carbon dioxide requires about 68 cubic meters of storage space. Under this condition, it is necessary to separate carbon dioxide from flue gas in order to treat it fully and effectively underground. about

In order to prevent CO2 leakage or migration, it is necessary to seal the whole storage space. Therefore, it is also important to choose a suitable sealing cover with good sealing performance, which can play the role of "amulet" and ensure the long-term storage of carbon dioxide underground.

A more effective method is to use conventional geological trap structures, including gas fields and oilfield aquifers. For the first two, using them to store carbon dioxide is more convenient and cost-effective, because they are part of the human energy system based on people's familiarity with their structure and geological conditions.

Aquifer, because it is very popular, has great potential for carbon dioxide storage.

According to the way of carbon sequestration, carbon sequestration can be divided into geological sequestration, marine sequestration, carbonate solid sequestration and industrial fixed sites and methods, and its development status is shown in the following table.

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Development status of carbon capture and storage technology,

CCS technology has been paid close attention to by the international scientific community and industry because of its consistency with the basic structure of the existing energy system, and especially by industrialized countries and the United States because of the limitation of energy resources. The European Union and Canada have made technical research plans to carry out theoretical, experimental, demonstration and applied research on CCS technology. According to the statistics of the International Energy Agency, up to now, there are 13 1 carbon capture commercial projects, 42 carbon capture R&D projects, 20 geological deposit demonstration projects and 6 1 R&D projects in the world. The famous Norwegian Sleipner project Weyburn project is in Canada and Algeria.

Salah project

BR/>； In recent years, in June 2002, Europe and the United States began to test the carbon dioxide emissions stored underground in peak power thermal power plants of the US Department of Energy and the US Electric Energy Company (AEP). The factory carried out a research project on the geological storage method of carbon dioxide in West Virginia;

In February, 2003, the research project of CO2 storage funded by Council of Europe was started, and the emissions of CO2 storage power plants in Denmark, Germany, Norway and Britain were analyzed. There are several demonstration projects in the world, including the CCS pilot project of 250MW IGCC coal-fired power plant.

The World Carbon Sequestration Leaders Forum held in Melbourne, Australia, confirmed on September 4th, 2004 that 10 experiments were conducted in 20 10 to strengthen international cooperation and promote scientific and technological projects, and the participating countries expressed strong interest in international cooperation on carbon sequestration.

Projects and experiments show that

CCS technology is a cutting-edge technology with great potential to reduce carbon dioxide emissions. Therefore, China should also pay close attention to the research status and latest progress of CCS technology and related technologies, and demonstrate its application in theory and experiment in the early stage of planning.

In this case, economic development and environmental protection will achieve a win-win situation. ：

Take the United States as an example. In 2000, the United States officially launched a research and development project on carbon dioxide sequestration sponsored by the US Department of Energy to study terrestrial ecosystems (forests, soils, vegetation, etc.). ) is the main research field, including geological storage and isolation storage of marine carbon dioxide, and a detailed technical roadmap has been formulated. Please refer to the table below for details.

In 2005, the United States conducted 25 field experiments on CO2 injection, storage and monitoring of underground structures, and now it has entered the verification stage.

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Development prospect and function of developing carbon capture and storage technology in China

In the development stage of China's national conditions, the energy structure is determined by carbon capture and storage technology (CCS), which is an important strategic choice for China to cope with climate change. Although the technology is still in the stage of research, development and demonstration, the positive actions and progress of many universities, scientific research institutions and enterprises in China, as well as the feasibility study of CCS center construction are also being fully understood. The existing problems of CCS technology are of great significance to China, which can improve China's carbon capture and storage capacity in response to climate change.

The entry into force of "Kyoto Protocol" has increased mankind's hope to cope with climate change, but it is relatively simple to reduce carbon dioxide emissions and improve energy efficiency by using renewable energy and other technical means. In the energy-driven modern society, fossil fuels will still be the main energy supply, and the pressure of carbon dioxide and other greenhouse gases is great. The concentration of greenhouse gases needs to be stabilized at a certain level, so comprehensive IPCC carbon capture and storage technology is needed to reduce it.

The so-called carbon dioxide is to store the carbon dioxide produced by burning fossil fuels in natural groundwater reservoirs for a long time through timely collection, collection and storage measures to reduce the emission of carbon dioxide to the atmosphere. This technology not only means an important choice for global greenhouse gas emissions, but also a fundamental measure to reduce the concentration of carbon dioxide in the atmosphere and achieve near-zero energy use.

In recent years, with the rapid economic growth in China, the demand for energy is increasing, and the greenhouse gas emissions have been in the forefront of the world, which has a far-reaching impact on China. In developing countries, extreme weather events, climate change, coal-based energy and the secondary energy structure of thermal power plants, as well as the frequency of carbon capture and storage are all very broad application prospects. In China, China's carbon emission reduction and tackling climate change will also become important technological options.

China CCS: In the R&D stage.

Since 1970s, China has been paying attention to the research of enhancing oil recovery by using carbon dioxide. Compared with international advanced practices, China's previous research and development of carbon dioxide capture CCS is still only suitable for some high-purity carbon dioxide, and it is easier to capture carbon in industrial production processes such as oil refining, ammonia, hydrogen and natural gas purification. The overall appearance of carbon dioxide capture and storage is still in the laboratory stage, but it is mainly captured after combustion, and its industrial application is mainly a major national project to improve oil recovery.

However, in recent years, China has done a lot of research on CCS. Since 2003, the "973 Plan" of the carbon capture leaders' forum, which was attended by the government of China, has included the "863 Plan" CCS. In addition, Huaneng and Shenhua have planned, studied and demonstrated 65,438+06 CCS projects in July 2008. In 2008, the first demonstration project of carbon capture in coal-fired power plants in China, Huaneng Beijing Thermal Power Plant, was officially completed and put into operation, marking the first application of carbon dioxide emission reduction technology in coal-fired power generation in China.

The first CCS center as a developing country, the Institute of Coal Information cooperated with the International Energy Agency to establish a CCS center, which will actively promote the development and demonstration of CCS technology, technology transfer and information sharing in China.

Realistic challenges facing CCS

CCS, as the basic technical means of greenhouse gas emission reduction, has great development potential, but its application will greatly change the traditional energy production form and affect the economic cost. There are great uncertainties in geological structure, marine ecology and human healthy earth circulation system, which will affect human living environment. The application will also change people's existing cognition, existing laws, regulations and policies, and social tolerance. The influence of CCS, the problems facing CCS;

& gt the cost is too high. At present, it is estimated that the application of CCS will increase the power generation cost by about 0.0 1-0.05 USD/kwh, exceeding 20% of energy consumption, which will hinder the development of CCS.

Health, safety and environmental risks. The application of CCS may be related to the risks brought by pipeline transportation, geological storage leakage and carbon dioxide injection into the ocean, which will affect human health, safety and ecological environment. The unpredictable potential risk of CCS has always been the main concern of the society, which is unacceptable, but it also hinders the development of CCS.

Lack of relevant laws and regulations, lack of an appropriate legal framework to promote the implementation of geological storage, and failure to consider long-term liabilities.

Lack of understanding of source and sink matching, risk assessment and monitoring. Understand the shortcomings of CCS; The capture, transportation and storage technology itself also needs in-depth study; Distance is the main source of carbon dioxide, and it is also to better understand and establish the storage point and the cost curve of capture, transportation and storage; It is necessary to improve the estimation of storage capacity at global, regional and local levels in order to better understand the long-term storage, flow and leakage process.