Study of Gamma Alumina Synthesis – Analysis of the Specific Surface Area

Abstract

Different samples of pseudoboehmite (PB) were synthesized through the sol-gel process, using aluminum nitrate as precursor. The influence of variables on the synthesis and calcinations of the PB on the specific area of the obtained gamma-Alumina were studied. The variables were the ageing temperature (25 and 130o C), addition or not of polyvinyl alcohol to the precursor solution and the ageing time of the PB. The pH adjustment of the precursor solution was made by using ammonium carbonate. The products, which were obtained on different conditions, were then characterized by x-ray diffraction, specific area measurements through the BET process, and by thermal analysis (DTA and TG). After characterization, the synthesis products were calcined at 500°C; during this process the gamma-Alumina transformation was observed. The calcination products were characterized by the same methods (x-ray diffraction, BET, DTA and TG) and the desorption-absorption curves were obtained as well, in order to measure the pore volume of the samples. Finally, the results were analyzed through an experimental factorial planning, which showed that high specific surface area gamma-Al2O3 (around 330m²/g) can be obtained through this process.

Experimental and Modeling Study of Organic Chloride Compounds Removal from Naphtha Fraction of Contaminated Crude Oil Using Sintered γ-Al2O3 Nanoparticles: Equilibrium, Kinetic, and Thermodynamic Analysis

“…The diffractograms for the sample display three distinct reflections at 38.3° (311 reflection), 45.7° (400), and 66.6° (440), which is in agreement with the database standard (JCPDS reference no. 00-010-0425) and also with the reported results in the literatures for γ-alumina. − …”

Simulation of Large Aggregate Particles System With a New Morphological Model

“…The effect of the synthesis conditions on the final dry solid multi-scale structure can be evaluated experimentally, by several techniques like Small Angle X-Ray Scattering (SAXS) (Sasanuma, 1989) and Nitrogen physisorption (Munhoz, 2014). An alternative way is to use numerical simulations, indeed, the description of the agglomeration kinetics with physical models, such as DLVO (Dergajuin, Landau, Verwey and Overbeek) (Verwey, 1948) theory enables to estimate the size distribution and fractal dimension of colloidal agglomerates for any set of pH, ionic strength and concentration.…”