## 5 Conclusions  
In this study, a new blending recipe of a polyamine-based solvent for the capturing of post-combustion CO\({}_{2}\) was proposed, and its performance and characteristics were investigated using a pilot-scale carbon capture process (PCCP). The proposed solvent was derived from three different IBD-based blends. All three blends contained PZ as a reaction-rate-enhancer and one of MEA, BAE, or AMP as an auxiliary amine to increase the total amine concentration while not increasing the viscosity substantially. Comparing the experimental measurements of CO\({}_{2}\) solubility, CO\({}_{2}\) absorption rate, and viscosity in the lab, IBD-AMP-PZ, abbreviated as IAP herein, was selected as the best solvent candidate and tested in a PCCP that can handle 150 Nm\({}^{3}\)/h of flue gas. To determine the  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Solvent**} & **I/G** & **Lean Loading** & **CO\({}_{2}\) Loading after the 1 st Column** & \begin{tabular}{c} **CO\({}_{2}\) Loading after** \\ **the 2 nd Column** \\ \end{tabular} & \
\begin{tabular}{c} **Working Capacity** \\ \end{tabular} &
\begin{tabular}{c} **Rebouiler Heat Duty** \\ \end{tabular} \\ \cline{2-6}  & **I/Nm\({}^{3}\)** & & **g-CO\({}_{2}\)/kg-Solvent** & & & \\ \hline MEA 30 mass\% & 4.3 & 51 & 75 & 95 & 44 & 4.0 \\ IAP & 1.7 & 4 & 108 & 130 & 126 & 3.3 \\ \hline \hline \end{tabular}
\end{table}
Table 7: CO\({}_{2}\) loadings at different locations for minimum reboiler heat duty.  
Figure 7: Temperature profiles in the absorber and stripper columns under the optimum operating conditions for MEA and IAP.  
performance and characteristics of the PCCP, a baseline evaluation was conducted with the MEA 30 mass% solvent. The proposed IAP solvent demonstrated highly stable operation and a reboiler duty that was approximately 0.7 GJ/t-CO\({}_{2}\) lower than that of MEA 30 mass% solvent. Excluding the heat loss, the reboiler heat duty of IAP was estimated to be approximately 2.9 GJ/t-CO\({}_{2}\). The absorber temperature profile under the optimal operating conditions indicated that the proposed solvent utilized the column more efficiently than MEA 30-mass%.  
Of course, the optimization ratio for IBD, AMP, and PZ must be determined through additional laboratory tests and PCCP operations. Stability analysis of IAP degradation by SO\({}_{2}\) should also be performed with pilot long-term demonstrations. In addition, for the commercialization of IAP, direct comparative evaluation with commercial solvents such as aMDEA(r) is required. These comparative assessments should be done in a larger scale process as well as the PCCP used in this study. Nevertheless, the IAP contained in the polyamine showed its potential as a direct CO\({}_{2}\) capture solvent through pilot demonstration.  
Conceptualization, H.K. ([PERSON]) and H.K. ([PERSON]); Methodology, J.K. and Y.L.; Formal analysis, H.J., T.P., and Y.L.; Writing--original draft preparation, Y.L. Writing--review and editing, K.S.L.; project administration and funding acquisition, S.P. All authors have read and agreed to the published version of the manuscript. This research was funded by the Korean government (Ministry of Science and ICT) grant number [171104870]. The authors are extremely thankful to Govt. of Korea. The authors declare no conflict of interests.