The Synthesis Of Boehmite With Large Pore Size And Large Specific Surface Area And Its Application In FCC

As with advantages such like large surface area, large pore volume, contorlable pore size and thermal stability in a wide temperature range, ?-Al₂O₃, which is called actived alumina, is one of the most important catalyst support materials in the field of petroleum chemical industry. ?-Al₂O₃ can be prepared by calcining boehmite at 400?700?, with largely preserving the morphological properties. It has been observed that the precipitation of aluminum hydroxides is dependent on the presence of co-existing anions in the reaction system, but there aren't any systematic researches about the effect of anions on the morphology and properties of boehmite in the process of synthesis was reported.Adhering to the principle of green chemistry, this thesis synthesized boehmite samples in hydrothermal way, and studied the boehmite samples synthesized with SO₄^2-,NO3- and Cl- to explore the effect of different anions on the morphology and properties of boehmite in the process of synthesis. Modefied boehmite with Si. And this thesis also prepared FCC catalyst with boehmite synthesized in the laboratory, comparing with industrial FCC catalyst.This study shows that SO₄^2- is more competitive than NO3- and Cl-, namely the boehmite will form the similar morphology of sheets folded together once in the presence of SO₄^2-,and the specific surface area and pore volume show the same rule. And SO₄^2- is more helpful to the synthesis of boehmite with large pore size and surface area. This thesis also shows that the introduction of Si promoted the thermostability of boehmite significantly, and the FCC catalyst based on boehmite synthesized in the laboratory has better catalytic properties than the industrial catalyst.