Supported Polytertiary Amines: Highly Efficient and Selective SO2 Adsorbents
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- 作者：Ritesh Tailor ; Mohamed Abboud ; Abdelhamid Sayari
- 刊名：Environmental Science & Technology
- 出版年：2014
- 出版时间：February 4, 2014
- 年：2014
- 卷：48
- 期：3
- 页码：2025-2034
- 全文大小：570K
- ISSN：1520-5851
文摘
Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 掳C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and 13C and 15N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.