Reaction parameter study for the chemical synthesis of adsorbent silica gel

Abstract

This article presents an appropriate set of reaction parameters (reaction temperature, sulphuric acid and sodium silicate reagent concentration) for obtaining adsorbent silica gel (ASG) using Colombian-produced raw materials. The core of ASG synthesis lies in sulphuric acid’s neutralisation reaction with sodium silicate. Their effect on final ASG moisture adsorption capacity was measured after changing such synthesis’ above-mentioned reaction parameters. Within the range of conditions studied, it was found that the highest adsorption capacity occurred by combining both low sodium silicate concentration with high temperatures or high sulphuric acid concentration and temperature. Synthesised ASG was also compared to a commercial product (Gel de silice granulare con indicatore. Montedison group. Batch number 1684G100. Code number 453301) using adsorption capacity plots, BET areas, X-ray diffraction, mass and infrared spectrometry and mechanical strength measurements. Synthesised ASG presented larger specific surface areas but weaker mechanical strength than the commercial one. Likewise, all evaluated samples exhibited a low degree of molecular arrangement and conventional ASG chemical structure.