Co2 Capture: State of the Art

The enhanced CO2 concentration in the atmosphere is directly proportional to the global warming. The atmospheric CO2 concentration is more or less 280 to 400 ppm during pre-industrial era and expected to enlist >500 ppm by 2050 [1,2]. Emission at the current rate would lead the adverse effect in the future could be larger as compared to the last century [3]. World energy consumption will see a 48% increase from 2012 to 2040 and fossil fuel sources will still account for 78% of the world energy consumption in 2040 [3]. The Paris Accord bind countries towards reduction of CO2 emissions by at least 50% are necessary to restrict the global temperature rise to 2°C by 2050[4]. Owing of hefty challenge, it is imperative to reduce CO2 emissions from fossil fuel consumption. Overall cost and the required energy is the bottlenecks towards commercialize the CO2 capture and storage process at large scale. Few technologies for instance physical or chemical solvent scrubbing, [5-7] gas membrane separation, [8-13] pressure swing absorption, [14,15] surface absorption and adsorption, [16-19] metal organic frameworks, [20-27] amine based technology [28] have been applied to the CO2 capture. Owing of the high energy consumption, storage, cost raised concerns towards widespread implementation of carbon capture storage. Recently, ionic liquids (ILs) have been emerging as potential contenders for CO2 capture due to their superior physicochemical characteristics, including low melting point, high thermal stability, adjustable structure, and good recyclability [29,30]. However, the solubility of CO2 in conventional ILs is limited due to the physical absorption. In order to achieve better performance, some special groups (e.g.−NH2, −OH) were introduced to the anion or the action of ILs. The amine-functionalized IL has been chosen as the most promising candidate for CO2 capture.