NaOH溶液吸收CO2的试验研究

Experimental study of CO_2 absorption by NaO H solution

为了满足国际海事组织对船舶CO2排放的要求,建立了一种针对船舶尾气CO2的循环吸收系统,利用Na OH溶液吸收CO2。Na OH溶液完成第一步吸收反应后在第二步反应中被还原,从而可以循环利用。分析了初始反应温度、Na OH浓度及溶液中的Na2CO3对CO2吸收率的影响,并计算了循环反应中Na OH的再生率和Ca O的过量系数。结果表明,Ca O过量系数为1.2时对CO2固化效果最佳,此时Na OH溶液再生率达79.31%。研究表明,Na OH溶液吸收船舶尾气中CO2的循环系统效率高、成本低。

In order to meet the CO2 emission requirements of the International Maritime Organization for Cargo-Shipping,this paper attempts to introduce a CO2 absorption system in which NaO H solution has been adopted for adsorbing CO2 from the exhaust gas. In so doing,it would be possible to reduce the CO2 emission to a great degree so as to come up to the demand of the so-called green shipping.The basic mechanism of the aforementioned system can be explained by the absorption of CO2 by NaO H solution at first,and,then,the same solution referred to in the first step tends to come up back to its original state by other alkaline agents with the NaO H being recycled,which has made it possible for us to achieve the double purposes both of the high absorption rate and the low cost. The experiment results we have gained demonstrate that the initial reaction temperatures,the NaO H concentrations and Na2CO3 solution can all have effect on the CO2 absorption rate in addition to the NaO H solution regeneration rate and CaO excessive coefficient correspondingly. However,it is also of a great need to account for the above said influential factors with their different effects on the CO2 absorption rate. Forexample,the initial reaction temperature tends to make adverse effects on the CO2 absorption rate with the optimal initial reaction temperature being at 45 ℃. What is more,the concentration of the NaO H solution in use can also be beneficial for the CO2 absorption,though the high concentration of the NaO H is likely to corrode the experimental apparatus. It is for the need to prevent and even avoid such a kind of corrosion that the favorite concentration should be set up at 4-6 mol / L. In addition,Na2CO3 solution also proves to have the ability to absorb CO2,whose absorption rate should be above70%,if the demand for the CO2 absorption rate is lower than 70%.In comparison with the high corrosive NaO H solution,a better choice in the case should be done with Na2CO3 solution. And,finally,it is necessary to point out that,when the excessive coefficient of CaO can be taken as 1. 2,it would be possible to make the highest regeneration rate of NaO H up to 79. 31%. Therefore,the experimental results we have gained have shown that this system we have developed is characteristic for its advantages of high efficiency and low cost,thus,enjoying a great superiority in CO2 absorption and a highly promising prospect in ship exhaust gas treatment area.