A Comparative Review of Binder-Containing Extrusion and Alternative Shaping Techniques for Structuring of Zeolites into Different Geometrical Bodies

Zeolites are crystalline metallosilicates displaying unique physicochemical properties with widespread applications in catalysis, adsorption, and separation. They generally obtained by a multi-step process that starts primary mixture aging, followed hydrothermal crystallization, washing, drying, and, finally, calcination step. However, the zeolites powder form because of generating pressure drop industrial fixed bed reactors, not applicable for purposes. To overcome such drawbacks, shaped into appropriate geometries desired size (a few centimeters) using extrusion, where zeolite powders mixed binders (e.g., mineral clays or inorganic oxides). The presence provides good mechanical strength against crushing zeolites, but may have adverse impacts on catalytic sorption properties, as active site dilution pore blockage. latter is more pronounced when binder has smaller particle size, which makes internal sites mainly inaccessible. In addition to shaping requirements, hierarchical structure different levels porosity (micro-, meso-, macropores) an interconnected network essential decrease diffusion limitation inside micropores well increase mass transfer larger auxiliary pores. Thus, generation its preservation during step great importance. aim this review provide comprehensive survey detailed overview binder-containing extrusion technique compared alternative technologies improved properties. An emphasis allocated those techniques been less discussed detail literature.