Mass transfer performance of a polypropylene hollow-fiber membrane contactor as part of a continuously operated CO₂ capture unit with amino acid salt (potassium glycinate) absorbent and vacuum solvent regeneration was studied. The effects of key operating parameters on the absorption mass transfer characteristics were explored. Without vacuum stripping, absorption rate was found to be limited by low CO₂ desorption efficiency from the loaded absorbent solution in the stripping unit, resulting in high solvent CO₂ loadings and limited chemical absorption rates. Introduction of vacuum stripping greatly improved desorption performance, resulting in improved steady-state absorption performance. The overall mass transfer coefficient increased at higher stripping temperatures and lower vacuum pressures in the range of 60−80 °C and 300−800 mbar (abs). The overall mass transfer coefficient increased with increasing liquid flow rate, and the highest value reached was 1.8 ∙ 10⁻⁴ m s^-1. The individual mass transfer coefficients in absorption were calculated based on mass transfer correlations and experimental data, including estimation of the enhancement factor for chemical absorption. The overall mass transfer resistance was found to be dominated by the liquid-side resistance, at almost 90 % of the total resistance. The estimated membrane mass transfer coefficient was low compared to a theoretical value assuming non-wetted operation, suggesting potential partial wetting of the membrane. Stable performance of the unit and the membrane contactor was demonstrated during a stability test with over 30 h of operation.

研究了聚丙烯中空纤维膜接触器的传质性能，该接触器是具有氨基酸盐（甘氨酸钾）吸收剂的连续操作CO ₂捕集单元的一部分，并进行了真空溶剂再生。探索了关键操作参数对吸收传质特性的影响。如果不进行真空汽提，则会发现吸收速率受到汽提单元中负载的吸收剂溶液中低的CO ₂解吸效率的限制，从而导致高溶剂CO ₂负载和有限的化学吸收率。真空汽提的引入大大提高了解吸性能，从而提高了稳态吸收性能。在较高的汽提温度和较低的真空压力（60-80°C和300-800 mbar（绝对值）的范围内），总传质系数会增加。总传质系数随液体流速的增加而增加，达到的最大值为1.8∙10 ^-4 ms ^-1。吸收中的各个传质系数是根据传质相关性和实验数据计算得出的，包括估算化学吸收的增强因子。发现总的传质阻力主要由液侧阻力控制，几乎占总阻力的90％。假设未润湿操作，估计的膜传质系数与理论值相比较低，表明膜可能存在部分润湿。在超过30小时的稳定性测试过程中，证明了装置和膜接触器的稳定性能。