超重力环境下甲基二乙醇胺选择性脱除H_2S的模拟

Simulation of Selective Absorption of H_2S with Aqueous N-Methyldiethanolamine Under High Gravity Field

应用反应-扩散模型对超重力环境下甲基二乙醇胺(MDEA)溶液从CO2和H2S混合气中选择性脱除H2S过程进行了定量描述。模拟结果表明,CO2在向MDEA溶液液膜渗透的过程中,需耗时1s渗透进2.0×10-5m才能够建立起稳定的浓度梯度;对于H2S,仅需约2.0×10-9s渗透进入液膜1.0×10-8m便可建立起稳定的浓度梯度,液膜中CO2的传质过程对于H2S的吸收基本没有影响;MDEA在液膜中存在扩散,H2S的存在对于CO2吸收的抑制作用明显。在旋转填充床中于不同的温度下进行了MDEA选择性脱除H2S的实验。实验结果表明,旋转填充床可以获得较高的H2S脱除率;反应-扩散模型的模拟结果和实验结果吻合较好。

Reaction-diffusion mass transfer model was established and applied to quantificational description of selective removal of H2S from gas mixture with 1% H2S,10% CO2 and 89% N2.The selective removal of H2S was carried out in a rotating packed bed（RPB） at various temperatures with 10% N-methyldiethanolamine（MDEA） as Absorption liquid.For CO2,penetration into the Absorption liquid with 2.0×10～（-5） m thickness film within 1 s was needed to establish steady concentration gradient.However,for H2S,penetration into the liquid film with 1.0×10～（-8）m thickness within just（2.0×）10～（-9）s 1 s was demanded.The CO2 mass transfer process did not affect H2S Absorption.MDEA could diffuse in the liquid film.Effect of H2S existence on CO2 Absorption was apparently negative.The experiment result showed that high H2S removal efficiency could be achieved in the RPB with high gravity field.The model results were found to be in good agreement with the experimental data.