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World climate change occurring mainly due to human activities has led to an environmental concern all over the planet. Global CO 2 emission has reached an alarming level which is regarded as the most lethal anthropogenic greenhouse gas emissions. To have a check on the carbon emissions, many clean coal technologies were proposed out of which Chemical Looping Combustion (CLC) technology came out as the most promising technology of all. The process of CLC avoids direct contact between the fuel and the air. It is based on the transfer of oxygen from air to fuel by means of a metal based oxygen carrier and this process is blessed with inherent sequestration of CO 2 . This paper presents a review of the CLC technology and it׳s all round advancement during last 10-15 years. The all round development of the process include progress in terms of the use of gaseous, solid as well as liquid fuels, the evolution in the oxygen carriers and the reactor systems being used in the process. The development in the oxygen carriers has gained maturity, the use of solid fuels is gaining momentum, and the liquid fuels need further attention for its development. Recently, a fair number of hours of continuous operation in pilot plants have instilled the confidence required in further development of this process towards commercialization. The big stride that the CLC technology has taken in such a small duration of time, there leaves no doubt that this technology has the potential to grow manifolds with further research. [ABSTRACT FROM AUTHOR]

Global warming and climate change concerns have triggered global efforts to reduce the concentration of atmospheric carbon dioxide (CO 2 ). Carbon dioxide capture and storage (CCS) is considered a crucial strategy for meeting CO 2 emission reduction targets. In this paper, various aspects of CCS are reviewed and discussed including the state of the art technologies for CO 2 capture, separation, transport, storage, leakage, monitoring, and life cycle analysis. The selection of specific CO 2 capture technology heavily depends on the type of CO 2 generating plant and fuel used. Among those CO 2 separation processes, absorption is the most mature and commonly adopted due to its higher efficiency and lower cost. Pipeline is considered to be the most viable solution for large volume of CO 2 transport. Among those geological formations for CO 2 storage, enhanced oil recovery is mature and has been practiced for many years but its economical viability for anthropogenic sources needs to be demonstrated. There are growing interests in CO 2 storage in saline aquifers due to their enormous potential storage capacity and several projects are in the pipeline for demonstration of its viability. There are multiple hurdles to CCS deployment including the absence of a clear business case for CCS investment and the absence of robust economic incentives to support the additional high capital and operating costs of the whole CCS process. [ABSTRACT FROM AUTHOR]

Natural changes in climate due to internal as well as external factors, like anthropogenic emission, fossil fuel combustion, transportation and heating which cause CO2 emissions is one of the major issues which causes global warming (increasing concentrations of greenhouse gases). The production of algae is identified as one of the solutions of carbon sequestration along with production of renewable fuel solving the problem of food crisis to a certain extent. This review paper summarizes how CO2 levels affected micro algal species. Several species of algae as Scenedesmus obliquus, Botryococcus braunii, Chlorella vulgaris, Nannochloropsis oculata have been reported to accumulate high concentration of lipid. These species are suitable for biofuel production as well as Carbon fixation. [ABSTRACT FROM AUTHOR]