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Bio-energy with carbon capture and storage (BECCS) is a greenhouse gas mitigation technology which produces negative carbon dioxide emissions by combining bioenergy (energy from biomass) use with geologic carbon capture and storage. The concept of BECCS is drawn from the integration of trees and crops, which extract carbon dioxide (CO2) from the atmosphere as they grow, the use of this biomass in processing industries or power plants, and the application of carbon capture and storage via CO2 injection into geological formations. There are other non-BECCS forms of carbon dioxide removal and storage that include technologies such as biochar, carbon dioxide air capture and biomass burial. According to a recent Biorecro report, there is 550 000 tonnes CO2/year in total BECCS capacity currently operating, divided between three different facilities (as of January 2012).〔〔(【引用サイトリンク】title= First U.S. large demonstration-scale injection of CO2 from a biofuel production facility begins )〕〔(【引用サイトリンク】title= Ethanol plant to sequester CO2 emissions )〕〔(【引用サイトリンク】title= Production Begins at Biggest Ethanol Plant in Kansas )〕 It was pointed out in the IPCC Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) as a key technology for reaching low carbon dioxide atmospheric concentration targets. The negative emissions that can be produced by BECCS has been estimated by the Royal Society to be equivalent to a 50 to 150 ppm decrease in global atmospheric carbon dioxide concentrations and according to the International Energy Agency, the BLUE map climate change mitigation scenario calls for more than 2 gigatonnes of negative CO2 emissions per year with BECCS in 2050. According to Stanford University, 10 gigatonnes is achievable by this date. The Imperial College London, the UK Met Office Hadley Centre for Climate Prediction and Research, the Tyndall Centre for Climate Change Research, the (Walker Institute for Climate System Research ), and the Grantham Institute for Climate Change issued a joint report on carbon dioxide removal technologies as part of the ''AVOID: Avoiding dangerous climate change'' research program, stating that "Overall, of the technologies studied in this report, BECCS has the greatest maturity and there are no major practical barriers to its introduction into today’s energy system. The presence of a primary product will support early deployment." According to the OECD, "Achieving lower concentration targets (450 ppm) depends significantly on the use of BECCS". ==Negative emission== The main appeal of BECCS is in its ability to result in negative emissions of CO2. The capture of carbon dioxide from bioenergy sources effectively removes CO2 from the atmosphere. Bio-energy is derived from biomass which is a renewable energy source and serves as a carbon sink during its growth. During industrial processes, the biomass combusted or processed re-releases the CO2 into the atmosphere. The process thus results in a net zero emission of CO2, though this may be positively or negatively altered depending on the carbon emissions associated with biomass growth, transport and processing, see below under environmental considerations. Carbon capture and storage (CCS) technology serves to intercept the release of CO2 into the atmosphere and redirect it into geological storage locations. CO2 with a biomass origin is not only released from biomass fuelled power plants, but also during the production of pulp used to make paper and in the production of biofuels such as biogas and bioethanol. The BECCS technology can also be employed on such industrial processes. It is argued that through the BECCS technology, carbon dioxide is trapped in geologic formations for very long periods of time, whereas for example a tree only stores its carbon during its lifetime. In its report on the CCS technology, IPCC projects that more than 99% of carbon dioxide which is stored through geologic sequestration is likely to stay in place for more than 1000 years. While other types of carbon sinks such as the ocean, trees and soil may involve the risk of negative feedback loops at increased temperatures, BECCS technology is likely to provide a better permanence by storing CO2 in geological formations.〔〔IPCC, (2005)( "Chapter 5: Underground geological storage" IPCC Special Report on Carbon dioxide Capture and Storage. ) Prepared by Working Group III of the Intergovernmental Panel on Climate Change (B., O. Davidson, H. C. De Coninck, M. Loos, and L. A. Meyer (eds.) ). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp195-276.〕 The amount of CO2 that has been released to date is believed to be too much to be able to be absorbed by conventional sinks such as trees and soil in order to reach low emission targets. In addition to the presently accumulated emissions, there will be significant additional emissions during this century, even in the most ambitious low-emission scenarios. BECCS has therefore been suggested as a technology to reverse the emission trend and create a global system of net negative emissions.〔〔〔 This implies that the emissions would not only be zero, but negative, so that not only the emissions, but the absolute amount of CO2 in the atmosphere would be reduced. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bio-energy with carbon capture and storage」の詳細全文を読む スポンサード リンク
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