https://doi.org/10.1016/j.egypro.2014.12.438
“Figure 2 shows the CO 2 mass transfer coefficients in blended solutions of ammonia with promoters at three CO2 loadings. Only 0.3 M promoters especially sarcosinate, PZ and 1-MPZ can improve the CO2 mass transfer coefficients in 3 M ammonia solutions significantly. The promotion effects of additives are still distinct at high CO2 loading. In contrast, the mass transfer coefficients for CO2 absorption in 5 M MEA decreases much faster than ammonia-based solutions. Among the six promoters, sarcosinate, PZ and 1 -MPZ shows the most significant effect on increasing CO2 absorption rate in aqueous ammonia solutions. Sarcosinate is reported to have good oxidative and thermal stability and environmentally friendly characteristics which is thought to be a clean solvent. Figure 3(left) shows the overall mass transfer coefficients (KG) as a function of temperature of three different solutions. The effect of temperature on the overall mass transfer coefficients is relatively small for all the three ammonia-based solutions. When the temperature increases from 279 to 298 K, the corresponding overall mass transfer coefficients are increased by only 5–12%. Figure 3(right) presents the
effect of SAR- concentration on the overall mass transfer coefficients for CO2 absorption in 3 M NH3+SAR- solutions at 288 K. The effect of SAR- additive concentration is pronounced when its concentration is low. However, when the SAR- concentration reaches a relatively high value, KG does not increase with the increase of SAR- concentration. The highest KG of CO2 in 3 M NH3 + SAR- solutions at 288 K is approximately 2.2 mmol/(s m2 kPa) which is quite close to the CO2 absorption performance into
5 M MEA at 313 K. ”
