Facilitated Transport Membranes Ftms For Co2 Capture Overview And Future Trends

Author : Ting-Yu Chen
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

DOWNLOAD NOW!

Download or read book New Sterically Hindered Polyvinylamine-containing Membranes and 13C NMR Study of Amino Acid Salts for Carbon Capture from Flue Gas written by Ting-Yu Chen and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Membrane processes offer several advantages that make them ideal for industrial gas separation applications, including modularity, versatility, and cost-effectiveness. Facilitated transport membranes (FTMs) have seen significant developments recently and provide an improved technology platform for post-combustion CO2 capture. In this research, two types of amine carriers incorporated in FTMs were investigated for carbon capture from flue gas. In the first section of this study, we developed an improved method to synthesize sterically hindered polyvinylamine, which was successfully used as a fixed-site carrier for the synthesis of thin-film FTMs. The use of sterically hindered polyamines has been shown to significantly improve the ability of membranes to transport CO2. Moderately hindered poly-N-methyl-N-vinylamine (PVAm-CH3) with a high molecular weight was synthesized through stepwise reductive amination. A fluorinated alcohol with high polarity was used in the synthesis to shift the equilibrium to the formation of the imine intermediate for higher N-methylation. The method of preventing over-alkylation resulted in an increased yield of the target product and prevented the formation of side products. PVAm-CH3 exhibited excellent CO2 facilitation with a CO2 permeability of 445.7 Barrer (1 Barrer = 3.349 x 10–16 mol m m–2 s–1 Pa–1) and a CO2/N2 selectivity of 70.3. The optimized PVAm-CH3 membrane containing incorporating the amino acid salt (AAS), 2-(1-piperazinyl)ethylamine sarcosinate (PZEA-Sar) exhibited a superior CO2 performance of 1071 GPU (1 GPU = 3.349 x 10–10 mol m–2 s–1 Pa–1) and a CO2/N2 selectivity of 183 at 57°C and a feed gas pressure of 111.64 kPa (1.5 psig). Density functional theory (DFT) calculations were performed to explain the enhanced performance of PVAm-CH3 membranes. Some AASs have been demonstrated to be effective mobile carriers in FTMs to achieve superior CO2 permeance and CO2/N2 selectivity for CO2 capture from flue gas. A deeper understanding of how the structures of different AASs affect the chemistry of the amine–CO2 reaction is essential for the future development of more efficient AAS mobile carriers. In the second part of this study, we used NMR spectroscopy to study the amine–CO2 reaction chemistry and the CO2 absorption properties of AASs. PZEA-Sar exhibited a higher CO2 loading and preference for the more efficient bicarbonate pathway as well as formed a uniform membrane, making it a more preferred mobile carrier. The positive correlation between the CO2 loading of AAS (mol CO2/g AAS) and the CO2 permeance of FTMs suggested that AAS with a higher CO2 loading may improve the performance of FTMs. The diffusion of carbamate products played the most important role in CO2 transport under low CO2 partial pressure. As the partial pressure of CO2 increased, the contribution from bicarbonate products became more significant. The lower CO2 absorption at a higher temperature suggests that the enhanced CO2 permeance in FTMs was promoted by the increased diffusion rate of amine–CO2 reaction products.