This document is an expanded abstract.
Summary
One of the greatest challenges we are facing in the 21st century is our ability to provide sustainable energy sources to meet the demands for quality of life and economic growth. As most of the energy today is provided from fossil fuels, huge amounts of CO2 and other greenhouse gases are emitted to the atmosphere, with negative effects on the environment. Depletion of fossil fuels and their associated environmental pollution lead scientists to the pursuit of renewable energy sources and clean energy. However, reducing dependency on fossil fuels is a major challenge for most economically advanced countries. To make fossil fuels clean, efficient, reliable and scalable technologies for CO2 capture from large sources should be developed to control CO2 emission in the short-medium term. Although some technologies for carbon capture are available in the market they still suffer from some limitations to be fully implemented at large scale.
Introduction
Conventional CO2 removal using aqueous alkanolamine solutions is energy intensive. This lead researchers to investigate various solids adsorbents for selective CO2 removal at low pressure ranges while requiring less energy for regeneration compared to alkanoamine solutions [1]. Various porous solids were tested for post-combustion CO2 capture including activated carbon [2], zeolites [3] and metal–organic frameworks (MOFs) [4]. Solid materials grafted or impregnated with amines were also studied to further increase the CO2 binding strength and hence CO2 uptake [5, 6]. Of particular interest are amine grafted zeolites that combine strong CO2 capturing zeolite micropores with the chemical binding of CO2 with amines [7]. Hierarchical zeolites, combining zeolite micropores and mesoporous domains, show increased surface area and pore volume compared to conventional zeolites. Functionalizing the mesoporous domains in such materials with amines can result in high CO2 uptake because both the active sites of the zeolite and the amine groups in the mesopore space can simultaneously capture CO2. However, there are very few studies of amine grafted hierarchical zeolites and the latter were prepared using expensive organics [7].
In this work we study the performance of amine grafted hierarchical zeolites, prepared from inorganic (i.e. inexpensive) routes, in CO2 capture. A series of zeolites with varying textural properties are synthesized and grafted with different amines and their performance is tested for CO2 adsorption.
