Diferenças nas propriedades texturais de microesferas ocas de sílica após conformação em diferentes pressões de compressão

Abstract

Adsorption is a process very used industrially in catalysis, separation and purification of gases. Thus, new powder adsorbents have been developed according to the needs of the processes. The use of adsorbents in powder form is not feasible, due to factors such as difficult handling, clogging of columns and increased pressure drop. In this way, the use of extruded products, such as pellets and granules, are more appropriate. There are several powder particle conformation processes and the development of a new extrusion technique using hollow silica microspheres (HMS) as adsorbent will be addressed in this work. A relevant point in this process will be the non-use of a binder, which makes the process more practical and economical. Different shaped samples were obtained using different compression pressures during a certain time and their textural properties were evaluated and compared. Thermogravimetric analysis and adsorption equilibrium isotherms of N2 at 77 K, CO2 at 273 K and H2O at 298 K were performed to characterize the molded samples. The results obtained in this work indicate that HMS can be shaped under different compression pressures without binder by the applied forming method. The calcination process, recommended for providing mechanical strength, did not change the adsorptive capacity in any of the evaluated conditions. In addition to both samples having the same mechanical resistance, reinforcing the ineffectiveness of the calcination process.