The objective of this research is to study for the first time the effect of adding l‐arginine (Arg) amino acid on the solubility of carbon dioxide in aqueous solution of N‐methyldiethanolamine (MDEA). The study was carried out at different mixing ratios of MDEA and Arg at a total concentration of 2 moles per litre. The CO₂ partial pressure varied from about 10 to 100 kPa, and the temperature varied from 293 K to 323 K. The experimental results showed improved solubility of CO₂ with the addition of Arg at CO₂ partial pressures below 20 kPa. However, for CO₂ partial pressure of above 20 kPa, the addition of Arg caused a decrease in the solubility of CO₂. The obtained loading data were correlated using a semiempirical (SE) vapour liquid equilibrium (VLE) model with an average absolute deviation (AAD) less than 4.1% between the predicted and the experimental values. An estimation of the heat of CO₂ absorption in the solution was obtained using an analytical expression for ΔH_abs derived from the SE model and was found to be in the range of 29‐ to 40‐kJ/mole CO₂. From the finding of this work, it is anticipated that the studied novel blended solvent will effectively reduce CO₂ capture costs as the CO₂ content of most gas streams is less than 20% by volume, which is specifically true for natural gas and a large number of industrial flue gas streams.

中文翻译：

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甲基二乙醇胺和精氨酸水混合物中的二氧化碳吸收

这项研究的目的是第一次研究添加l-精氨酸（Arg）氨基酸对N-甲基二乙醇胺（MDEA）水溶液中二氧化碳溶解度的影响。该研究是在MDEA和Arg的不同混合比例下进行的，总浓度为每升2摩尔。CO ₂分压在约10至100 kPa之间变化，温度在293 K至323 K之间变化。实验结果表明，在低于20 kPa的CO ₂分压下，添加Arg可以提高CO _2的溶解度。然而，对于高于20 kPa的CO ₂分压，添加Arg会导致CO ₂溶解度降低。使用半经验（SE）气液平衡（VLE）模型对获得的载荷数据进行关联，其平均绝对偏差（AAD）小于预测值和实验值之间的4.1％。使用从SE模型得出的ΔH _abs的解析表达式，可以估算溶液中CO ₂吸收的热量，发现其范围为29至40 kJ / mol CO ₂。从这项工作的发现，可以预期，所研究的新型混合溶剂将有效降低CO ₂捕集成本，因为CO ₂ 大多数气流的含量少于20％（体积），这尤其适用于天然气和大量工业烟道气。