High-speed shear mixing: Versatile strategy towards the sustainable design of amine-supported CO2 adsorbents

Abstract

Dual asymmetric centrifuge high-speed shear mixing is introduced as a versatile and rapid dry method for physically impregnating solid adsorbents with amine compounds. Unlike wet impregnation, which is the most reported method in literature, the dry process enables impregnating the supporting material by both low (pentaethylenehexamine) and high molecular weight amines (branched polyethyleneimine, M_w ∼ 800 g.mol⁻¹) without using any solvent. High-speed shear mixing yields materials with CO₂ adsorption/desorption abilities (simulating direct air capture and flue gas, which includes cycling) comparable to those prepared by wet impregnation, while significantly reducing the preparation time and energy consumption and decreasing the use of toxic substances. Thus, the preparation procedure for CO₂ adsorbents can be successfully transformed into a clean, energy-efficient, and solvent-free process that supports sustainable development and mitigates climate change, and also be simultaneously applied to any other class I adsorbents.