A Novel Process for the Preparation of Binder‐Free Zeolite Beads (Lta‐5a) via Photopolymerization Applied in Co₂ Adsorption Field

Abstract

The increasing CO2 concentration in the atmosphere has a severe influence on both the environment and human health, resulting in global warming. According to the high adsorption capacity for CO2 removal, zeolites play an important role for CO2 capture and sequestration. However, its powdery form limits their use in adsorption applications. When binding agents are used, the zeolite porosity is partially occluded that compromises the CO2 adsorption capacity severely. How to prepare binder‐free zeolite beads with a certain structure strength and how to keep the high surface area and porosity are a great challenge. In this work, LTA‐5A beads composites (80 wt.%) are prepared via cationic photopolymerization and then calcination is performed to remove organic part to obtain LTA‐5A beads with different sizes (<1.0 mm, 1.0–2.0 mm, and 2.0–3.0 mm). These beads (0.1 g) are characterized by good mechanical strength without any binder (partial bead fragmentation under 200 g‐load) with a preserved zeolite porosity. This method allows to exploit the zeolite beads reaching a high specific surface area (586 688 m2 g−1) and good CO2 adsorption capacity (4.5‐4.9 mmol g−1). These values are higher than those of commercial LTA‐5A beads (515 m2 g−1 and 3.8 mmol g−1, respectively), which is in agreement with their binder‐free structure.

A Multifunctional Technology Platform for Sorbent Construction Using Polyacrylonitrile Scaffolds

“…Production of engineered forms of particulate sorbents can be realized through different approaches, depending on the type of sorbent. These include mixing them with another binder-type material (e.g., clay, polymer) and extruding or using wet granulation to create a desired size fraction, , using hard templates, using cationic photopolymerization followed by calcination, pressing the material into pellets and grinding to a desired size fraction, or embedding the active material into a passive matrix and forming the composites through a freezing technique. − The process of embedding (or affixing) active getters into passive matrices using a freezing process − has high potential toward providing solutions for a wide range of applications.…”