Heat of adsorption in the fly ash zeolite – CO2 system at dynamic conditions

The global warming represents one of the main world problems in the recent decades as it is considered that electricity production by coal burning is responsible for 40 % of the total CO2 emissions. The post-combustion capture of CO2 based on physical adsorption has the highest potential for meeting the industrial needs. Development of new sorbents, especially including solid waste utilization such as zeolitization of coal ash, would improve the process’ parameters in terms of economic feasibility, safety, and environmental protection. The adsorption processes’ nature is complex and is described by many empirical constants which are experimentally determined for individual contact systems. In this study the heat of adsorption in the system fly ash zeolite (FAZ) – CO2 is experimentally investigated. The performed technique includes on-line measurements of temperature increase during the exothermic adsorption process in laboratory adsorption column filled with FAZ. The sample is under continuous flow of 30 ml/min pure CO2. The exothermic peak is registered at 95 s and the detected temperature increase is 32.88 oC. The calculated specific heat of adsorption amounts to Hads=36.83 kJ/kg. Acknowledgements This work was financially supported by the NSF, Ministry of Education and Science of Bulgaria under contract DM 17/6.