γ-Al2O3, was called “ activated alumina”, is a kind of porous high dispersion solid materials, because of its adjustable pore structure, large specific surface area, good adsorption performance, surface with the advantages of acidity and good thermal stability, microporous surface with requisite properties of catalytic action, therefore become the most widely used catalyst, catalyst carrier and chromatography carrier in the chemical and oil industry, and plays an important role in the oil hydrocracking, hydrogenation refining, hydrogenation reforming, dehydrogenation reaction and automobile exhaust purification process.
Gamma-Al2O3 is widely used as catalyst carrier because of the adjustability of its pore structure and surface acidity. When γ- Al2O3 is used as a carrier, besides can have the effects to disperse and stabilize active components, also can provide acid alkali active center, synergistic reaction with the catalytic active components. The pore structure and surface properties of catalyst depend on γ-Al2O3 carrier, so high performance carrier would be found for specific catalytic reaction by controlling the properties of gamma alumina carrier.
Gamma activated alumina is generally made of its precursor pseudo-boehmite through 400~600℃ high temperature dehydration, so the surface physicochemical properties is largely determined by its precursor pseudo-boehmite, but there are many ways to make pseudo-boehmite, and different sources of pseudo-boehmite leads to the diversity of gamma – Al2O3. However, to those catalysts with special requirements to alumina carrier, only rely on the control of precursor pseudo-boehmite is difficult to achieve, must be taken to prophase preparation and post processing combining approaches to adjust the properties of alumina to meet different requirements. When the temperature is higher than 1000 ℃ in use, alumina occurs following phase transformation: γ→δ→θ→α-Al2O3, among them γ、δ、θ are cubic close packing, the difference only lies in the distribution of aluminum ions in tetrahedral and octahedral, so these phase transformation does not cause much variation of the structures. Oxygen ions in alpha phase are hexagonal close packing, aluminum oxide particles are grave reunion, specific surface area declined considerably.
Type |
Plastic bag |
Drum |
Drum |
Super sack/Jumbo bag |
Bead |
25kg/55lb |
25 kg/ 55 lb |
150 kg/ 330 lb |
750kg/1650lb 900kg/1980lb 1000kg/ 2200 lb |