The competitive and cooperative reactions between the intramolecular primary and secondary amino groups in CO₂ absorption have been investigated in this work. N-Methylethylenediamine (MEDA) and N-methylpropane-1,3-diamine (MAPA) were studied with various CO₂ loadings at 25 °C. The ¹³C NMR technology was employed to obtain accurate ¹³C peak areas and chemical shifts for determining the concentration of each species in both of the diamine-CO₂H₂O systems. The results showed that the relative amounts of the species is primary-carbamate >> secondary-carbamate > di-carbamate in the CO₂ absorption process. Moreover, the relative hydrolysis order of the carbamates is di-carbamate > secondary-carbamate > primary-carbamate. The competitive and cooperative reaction mechanism was then proposed based on these results. Finally, it was found that in both the MEDA and the MAPA ternary systems, the whole CO₂ absorption process can be divided into three stages: competitive stage, buffer stage and hydrolysis stage, each of which showed a different trend in the amount of each species as well as in the pH value.

在这项工作中，已经研究了分子内伯氨基和仲氨基之间在CO ₂吸收中的竞争性和协同反应。Ñ -Methylethylenediamine（MEDA）和Ñ -methylpropane -1,3-二胺（MAPA）与各种CO进行了研究₂负载量在25℃下。采用¹³ C NMR技术获得准确的¹³ C峰面积和化学位移，以确定两种二胺-CO ₂ H ₂ O系统中每种物质的浓度。结果表明，CO ₂中该种类的相对量为伯氨基甲酸酯>>仲氨基甲酸酯>二氨基甲酸酯吸收过程。此外，氨基甲酸酯的相对水解顺序为二氨基甲酸酯>仲氨基甲酸酯>伯氨基甲酸酯。基于这些结果，提出了竞争与合作反应机制。最后，发现在MEDA和MAPA三元系统中，整个CO ₂吸收过程都可以分为三个阶段：竞争阶段，缓冲阶段和水解阶段，每个阶段的数量都有不同的趋势。种类以及pH值。