Fe(Ⅲ)-EDTA吸收羰基硫动力学研究

Absorption Kinetics of Carbonyl Sulfide in Aqueous Solution of Fe(Ⅲ)-EDTA

在合成氨原料气中,羰基硫(COS)占有机硫的80%左右,天然气中COS亦高达500ppm,为了经济有效地脱除COS,作者经过筛选实验发现乙二胺四乙酸络合铁(Fe(Ⅲ)-EDTA)可以脱除COS,故对Fe(Ⅲ)-EDTA吸收COS的动力学进行了研究,揭示了该过程的控制步骤,建立了其数学模型,并提出了对该方法进行改进的可行性方案.

The absorption kinetics of carbonyl sulfide in aqueous solution of Fe(Ⅲ)-EDTA was studied by using a gas-liquid double mixing gradientiess contactor. The effects of absorption temperature, interface concentration of carbonyl sulfide, the pH of solution and the concentration of Fe(Ⅲ)-EDTA on the absorption rate of carbonyl sulfide in aqueous solution of Fe(Ⅲ)-EDTA were examined. The experimental results showed that the absorption rate was controlled by the hydrolysis reaction rate of carbonyl sulfide in liquid phase. Under the experimental conditions, the absorption rate can be expressed by the following equation: where the dimension of NA is mol/(m2·s). According to the experimental results and Pearson's general principle of reaction for soft and hard acids and bases, feasible plans for improving the performance of carbonyl sulfide absorption in aqueous solution of Fe(Ⅲ)- EDTA were proposed.