Epoxide-functionalization of polyethyleneimine for synthesis of stable carbon dioxide adsorbent in temperature swing adsorption.

Woosung Choi,Minkee Choi,Kyungmin Min,Yong-Ki Park,Young Soo Ko,Hwimin Seo,Jae Wan Jeon,Chaehoon Kim

doi:10.1038/ncomms12640

Abstract

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g−1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation.

Highlights

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas
The CO2 emissions associated with human activities are mainly due to the use of fossil fuels, and the implementation of CO2 capture and storage technologies in power plants has been proposed as a means of enabling the continued use of fossil fuels in the short term[2,3]
We report a highly versatile and scalable synthesis of functionalized-PEI/silica composite adsorbent that (2.2 msmimoul lgtaÀn1e)oausslwy elelxahsibloitnsg-atermlargsteabCiliOty[2] working in a temperature swing adsorption (TSA)

Summary

Introduction

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. Earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. We report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g À 1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. As critically mentioned in several papers[6,7,22,28], most previous studies have primarily focused on increasing the CO2 uptake of adsorbents during the adsorption step, and there have been very few reports describing practically meaningful regeneration methods for the adsorbents. Considering that material syntheses requiring the use of corrosive and expensive chemicals and multi-step procedures are difficult to scale up, an enormous gap appears to exist between many of the current academic studies and practical adsorbent development

Methods

Results

Conclusion