碳酸钾-三乙烯四胺复合溶液吸收模拟烟气中CO_2试验研究

本菲尔溶液在工业脱除二氧化碳中已获得较广泛的应用,但存在吸收速率差、再生负荷高等缺点。开发新型复合溶液成为目前研究热点。采用搅拌实验装置,研究不同配比的碳酸钾-TETA复合溶液对烟道气中二氧化碳的吸收和解吸性能,揭示了吸收速率、吸收容量与酸碱度、时间之间的内在联系,并对CO2从复合溶液中初始逸出温度、溶液再生温度、溶液再生率、再生前后溶液pH下降率进行了细致记录分析。实验结果表明:碳酸钾-TETA复合溶液配比为0.6∶0.4时吸收效果最佳,吸收量约为0.914mol/L;同时再生温度最低,为106℃;再生率最高,为96.7%。与相同配比的碳酸钾-MEA(一乙醇胺)、碳酸钾-DEA(二乙醇胺)、碳酸钾-DETA(二乙烯三胺)复合溶液相比具有一定再生优势。实验结果还表明碳酸钾-TETA复合体系之间存在正交互作用。

EXPERIMENTAL RESEARCH ON CARBON DIOXIDE ABSORPTION FROM SIMULATED FLUE GAS BY A K2CO3-TETA MIXED AMINE SOLUTION

Although hot alkaline solution of potassium has been widely used for decarbonization in the industry,several disadvantages such as poor absorption rate and high regeneration load still remain.So it becomes a hot topic for the development of new types of thermal compound alkaline potassium solution.A set of stirring experiment was conducted to evaluate the capability of absorption and desorption of carbon dioxide from flue gas by potassium carbonate solution with different proportions of potassium carbonate-TETA complex solution.The relationships between absorption rate,absorption capacity,pH and time were revealed.Based on a carefully recorded experimental data,the initial escape temperature of CO2,regeneration temperature,regeneration rate,and pH decline rate in regeneration were analyzed.The results show that the highest efficiency for CO2 absorbing can be reached when a ratio of K2CO3:TETA is 0.6∶0.4 in a binary complex system,with an absorption capacity of 0.914 mol//L.A high regeneration rate can be up to 96.7%,while the regeneration temperature can be as low as 106℃.Compared with potassium carbonate-MEA,potassium carbonate–DEA and potassium carbonate-DETA,the potassium carbonate-TETA performs excellence in regeneration with the same ratio of components.It also indicates a positive interaction between potassium carbonate and TETA solution.