A comparative study on energy efficient CO2 capture using amine grafted solid sorbent: Materials characterization, isotherms, kinetics and thermodynamics

Abstract

Excessive emission of CO2 is the main reason for the greenhouse effect. Amine-functionalized solid sorbents are promising candidates for reducing CO2 emissions, while sorbent quality depends greatly on the support. Herein, a new type of aluminosilicate solid acid support with a high specifical surface area of 412 m2/g and an acid amount of 7.88 mmol/g was fabricated using a low-energy hydrothermal free method. The fabricated aluminosilicate support and a benchmark MCM-41 porous silicate were then functionalized through chemical grafting of (3-Aminopropyl)triethoxysilane (APTES), and subsequently applied for CO2 capture. The results revealed that the amine loading and CO2 adsorption capacity of the fabricated aluminosilicate support were comparable with those of the benchmark MCM-41 porous silicate. Moreover, the fabricated sorbent exhibited low adsorption and desorption activation energy of 14.47 and 51.05 kJ/mol, which were 32% and 20% lower, respectively, than those of the benchmark one. The lower adsorption activation energy was found to be associated with the lower CO2 transfer resistance, whereas the lower desorption activation energy was attributed to the unique catalytic effect induced by the protons and Al atoms of the support. Our results indicate new possibilities in energy saving preparation of amine-based solid sorbent for energy efficient CO2 capture.