Design of carbon dioxide absorption from polluted city air

Abstract

Global climate change is the most serious environmental problem which the world is facing now. To avoid dangerous climate change, the growth of atmospheric concentrations of greenhouse gases must be halted and may have to be retarded. The concentration of carbon dioxide, CO2, the most dominant greenhouse gas, has increased from 280ppm in the pre-industrial age to more than 380ppm now and is now increasing by more than 2ppm per year driven by global CO2 emissions that are now increasing at more than 3.3% per year. Controlling the level of carbon dioxide in the atmosphere without limiting access to fossil energy resources is only possible if carbon dioxide is collected and disposed of from the atmosphere. While it may be cost-advantageous to collect the carbon dioxide at concentrated sources without ever letting it to enter the atmosphere but this approach is not available for the many diffuse sources of carbon dioxide. Similarly, for many older plants a retrofit to collect the carbon dioxide is either impossible or prohibitively expensive. For this reason current research investigate the possibility of collecting carbon dioxide directly from the atmosphere. In this case a small scale packed column was designed to be portable and can be operated in polluted city centers. 2-amino-2-methyl-1-propanol (AMP) solution was used as absorbent in the packed column. In order to investigate efficiency of the proposed design by employing mass and heat transfer equations a model was proposed for the system. The model was solved numerically and was validated successfully with experimental data of the literature. Finally the model was used to predict carbon dioxide removal from Tokyo city. It was found that the contactor able to capture at least 50% at each run which is designed in small scale. Furthermore, a parameter sensitivity test including physicochemical properties and operation condition was carried out.