Absorption of Carbon Dioxide in a Bubble-Column Scrubber

In the current stage over 85% of world energy demand is supplied by fossil fuels. Coal-fired plants discharged roughly 40% of the total CO2 are the main contributors in CO2 emissions (Kim & Kim, 2004; Yang et al., 2008). Environmental issues caused by exhaust green house gases (GHG) and toxics have become global problems. Through the past studies of five decades, increased GHG levels in atmosphere is believed to cause global warming, in which CO2 is the largest contributors. International Panel on Climate Change (IPCC) predicts that the CO2 content in atmosphere may contain up to 570 ppmv CO2, causing an increase in mean global temperature around 1.9°C and an increase mean sea level of 38m (Stewart & Hessami, 2005). Also accompanied is species extinction. Therefore, the importance of removing carbon dioxide from exhaust emissions has been recognized around the world. There are three options to reduce total emission into the atmosphere, i. e., to increase energy efficiency, to use renewable energy, and enhance the sequestration or removal of CO2. However, from the viewpoints of coal-fired plants discharged a lot amount of CO2-gas, CO2 gas needs to be removed from the flue gases of such point sources before direct sequestration. There are several processes for CO2 separation and capture processes, including post-combustion, pre-combustion, oxy-fuel processes, and chemical-looping combustion (Yang et al., 2008). In here, we focus on the treatment of post-combustion processes since they are typical coal-fired plants.