A Fundamental Study On Carbon Dioxide Absorption Using The Solution Method

On February 16, 2005, the Kyoto Protocol that aims at reducing the emission of CO₂ became effective, which made the recovery, stability, utility and re-source of CO₂ an attentive problem by international countries. The fossil-fuel power plant that mainly combusts the coal is the large family which emissions CO₂, and if the CO₂ in fuel gas can be recovered, it is a work that has both better social and economic benefits.The solution method is the most economical method for absorption of low concentration CO₂. We conducted preliminary experiments in order to study more effective absorbents and to further develop such kind of research and accumulate necessary and valuable experimental data.The corresponding relation between CO₂ concentration and pH was analyzed and the feasibility of detecting CO₂ concentration by pH method was discussed. Experimental results show that this method possesses the characteristics of convenience and simplicity, and for single amine the measured results are highly accurate, however, the relative error for compound amines is larger.We also took experiments on the absorption condition of CO₂ in packed tower, and detected the effect of the liquid-gas flow rate and CO₂ concentration on absorbent efficiency. Since in our experiments the spray density is larger than actual industrial production, the absorption model appropriate for industrial application was not established, and we only compared the CO₂ absorption ability of different solutions, so as to offer guidance on how to select highly efficient and feasible formula for compound amines absorbent solutions.In industrial production, all the process of CO₂ enrichment is recycled by absorption and regeneration, and the solution consumption during regeneration directly results in the cost of solution recovery. The performed experiments on solution regeneration are helpful to choose more economical and effective absorbents. We measure the regeneration ability of CO₂ at high temperatures to obtain the data of equilibrium concentration at different temperatures. The actual industry application was simulated and regeneration performance of saturated solution was investigated at different temperatures in packed tower. The experimental data received from those two works can provide references for actual production.