Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai-400 019 India.
Environ Sci Technol. 2010 Mar 15;44(6):2138-43. doi: 10.1021/es902805p.
N,N-Diethylethanolamine (DEEA) is a very promising absorbent for CO(2) removal from gaseous streams, as it can be prepared from renewable resources. Aqueous mixtures of DEEA and piperazine (PZ) are attractive for the enhancement of CO(2) capture, due to the high CO(2) loading capacity of DEEA and high reactivity of PZ. In the present work, for the first time, the equilibrium and kinetic characteristics of the CO(2) reaction with such mixtures were considered. Kinetic data were obtained experimentally, by using a stirred cell reactor. These data were interpreted using a homogeneous activation mechanism, by which the investigated reaction was considered as a reaction between CO(2) and DEEA in parallel with the reaction of CO(2) with PZ. It is found that, in the studied range of temperatures, 298-308 K, and overall amine concentrations, 2.1-2.5 kmol/m(3), this reaction system belongs to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO0 reaction with PZ was determined from the absorption rate measurements in the activated DEEA solutions, and its value at 303 K was found to be 24,450 m(3)/(kmol s).
N,N-二乙基乙醇胺 (DEEA) 是一种很有前途的从气体流中去除 CO2 的吸收剂，因为它可以从可再生资源中制备得到。由于 DEEA 具有较高的 CO2 负载能力和 PZ 的高反应性，因此 DEEA 和哌嗪 (PZ) 的水混合物对于增强 CO2 捕获具有吸引力。在本工作中，首次考虑了此类混合物与 CO2 的平衡和动力学特性。通过使用搅拌池反应器实验获得了动力学数据。使用均相活化机制对这些数据进行了解释，该机制将研究的反应视为 CO2 与 DEEA 的平行反应，以及 CO2 与 PZ 的反应。结果发现，在所研究的温度范围内，298-308 K 和总胺浓度 2.1-2.5 kmol/m3，该反应体系属于快速拟一级反应体系。在活化的 DEEA 溶液中通过吸收速率测量确定了 CO0 与 PZ 的二级反应速率常数，在 303 K 下其值为 24,450 m3/(kmol s)。
