Amine volatility may be a critical problem with biphasic solvent for CO₂ capture such as the blend of 2-(diethylamino)-ethanol (DEEA) and 2-((2-aminoethyl) amino) ethanol (AEEA). The Henry’s law constant (H_am) of DEEA and AEEA in water at 40 and 50 °C was measured using a hot gas FTIR. DEEA is 20–30 times more volatile than monoethanolamine (MEA) while AEEA is nearly non-volatile. At lean loading, the amine volatility is 327 ppm in 12 m DEEA and 1.1 ppm in 2.5 m AEEA at 40 °C. The NRTL model shows good consistency with the DEEA-H₂O data for amine and water activity coefficients. Amine volatility in 12 m DEEA with 0 to 0.4 mol CO₂/mol DEEA and in 2.5 m AEEA with 0 to 0.9 mol CO₂/mol AEEA at 40 and 50 °C was also measured. DEEA partial pressure (P_DEEA) increases with CO₂ loading even though there is less free DEEA in the loaded solutions. The ionic reaction products of DEEA and CO₂ increase the ionic strength and DEEA activity coefficient. The effect of ionic strength on the DEEA activity coefficient was confirmed with data for 12 m DEEA-H₂O-KNO₃ and 12 m DEEA-H₂O-H₂SO₄. AEEA partial pressure (P_AEEA) decreases with CO₂ loading as AEEA is converted by the reaction with CO₂ to other non-volatile species.

胺的挥发性可能是用于捕获CO _2的双相溶剂（例如2-（二乙基氨基）-乙醇（DEEA）和2-（（2-氨基乙基）氨基）乙醇（AEEA）的混合物的关键问题。使用热气体FTIR测量DEEA和AEEA在40和50°C的水中的亨利定律常数（H _am）。DEEA的挥发性是单乙醇胺（MEA）的20–30倍，而AEEA几乎是非挥发性的。在稀负荷下，胺的挥发性在40°C下在12 m DEEA中为327 ppm，在2.5 m AEEA中为1.1 ppm。NRTL模型与胺和水活度系数的DEEA-H ₂ O数据显示出良好的一致性。在具有0至0.4 mol CO ₂ / mol DEEA的12 m DEEA和具有0至0.9 mol CO _2的2.5 m AEEA中的胺挥发性还测量了在40和50°C下的/ mol AEEA。即使加载的溶液中游离DEEA较少，DEEA分压（P _DEEA）也会随CO ₂加载而增加。DEEA和CO ₂的离子反应产物增加了离子强度和DEEA活性系数。离子强度对DEEA活性系数的影响已通过12 m DEEA-H ₂ O-KNO ₃和12 m DEEA-H ₂ O-H ₂ SO _4的数据证实。随着AEEA通过与CO ₂反应转化为其他非挥发性物质，AEEA分压（P _AEEA）随CO ₂负载的增加而降低。