中空纤维膜接触器中N,N-二甲基乙醇胺吸收CO2的特性

N,N-二甲基乙醇胺（DMEA）是一种很有前途的吸收剂，具有较快的反应速率和较高的CO₂捕集能力。在本研究中，DMEA作为一种新型吸收剂被应用于中空纤维膜接触器，用于从CO₂/CH₄气体混合物中分离CO₂。通过建立二维稳态数学模型，模拟了MEA、DEA、MDEA和DMEA四种吸收剂在不同操作条件下对CO₂吸收性能的影响。结果表明，脱碳性能大小为MEA>DMEA>DEA>MDEA；气相参数对脱碳率的影响比液相参数更显著；提高气体流速和CO₂浓度，脱碳率均会下降；提高液速和吸收剂浓度，脱碳率均增大，适当提高吸收剂流速和吸收剂浓度可以提高CO₂去除效率。此外，CO₂吸收通量将随着气体速度的增加而增加，随着液相中CO₂负荷的增加而减少。最后，通过两种影响因素共同作用确定了膜接触器分离酸性气体的最佳操作条件。因此，膜吸收法在天然气脱碳方面有良好的潜力。

Characteristics of CO2 absorption by N,N-dimethylethanolamine (DMEA) in hollow fiber membrane contactor

N,N-dimethylethanolamine (DMEA) is a promising absorbent because of its fast reaction rate and high CO₂ trapping ability. In this study, DMEA, as a new type of absorbent, was used in hollow fiber membrane contactors to separate CO₂ from CO₂/CH₄ gas mixtures. A two-dimensional steady-state mathematical model was established to simulate the effects of MEA (monoethanolamine), DEA (diethanolamine), MDEA (N-methyldiethanolamine) and DMEA on the absorption properties of CO₂ under different operating conditions. The results showed that the decarbonization performance was MEA>DMEA>DEA>MDEA, the effect of gas phase parameters on decarbonization rate was more significant than liquid phase parameters, the decarbonization rate decreased with the increase of gas flow rate and CO₂ concentration, the decarbonization rate increased with the increase of liquid velocity and absorbent concentration, and the removal efficiency of CO₂ can be improved by properly increasing absorbent flow rate and absorbent concentration. In addition, the CO₂ absorption flux will increase with the increase of gas velocity and decrease with the increase of CO₂ load in the liquid phase. Finally, through the joint action of two influencing factors, the best operating conditions of membrane contactor for acid gas separation were determined. Therefore, membrane absorption had good potential in natural gas decarbonization.