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US 6,642,172 B1Granted
Extruded catalyst based on silica/alumina gel
AssigneesEniricerche S.p.A., Agip Petroli S.p.A., Enichem Synthesis S.p.A.
InventorsCarlo Perego, Gianluca Bassi, Gianni Girotti
Life of this patent
Estimating the term…
Abstract
A catalyst in the form of extruded bodies is disclosed, which consists of an inert binding agent and a catalytically active phase of a silica/alumina gel. The catalyst is particularly active in acid-catalysed reactions.
Claims8
An extruded catalyst consisting of:
- a catalytically active portion of silica/alumina gel having a silica/alumina molar ratio ranging from 50:1 to 500:1 and an inert binding agent, which is prepared by:
- (a) preparing an aqueous solution of a tetraalkylammonium hydroxide (TAA—OH), a soluble aluminum compound capable of yielding Al2O3 by hydrolysis and a silicon compound capable of yielding SiO2 by hydrolysis, in the following molar ratios:
- SiO2:Al2O3=from 50:1 to 500:1
- TAA—OH:SiO2=from 0.05:1 to 0.2:1
- H2O:SiO2=from 5:1 to 40:1;
- (b) heating the resulting solution (a) in order to effect hydrolysis and gelation of the components of solution (a) thereby obtaining mixture (A) having a viscosity within the range of from 0.01 to 100 Pa sec;
- (c) adding to said mixture (A), firstly a binding agent selected from the group consisting of a boehmite and a pseudo-boehmite, in a ratio, by weight, to said mixture (A) within the range of from 0.05 to 0.5, followed by a plasticizer, and then adding an organic acid in an amount within the range of from 0.5 to 8 g per 100 g of binding agent;
- (d) mixing the combined material of step (c) and heating the mixture to a temperature within the range of from 40 to 90° C. until a homogeneous paste is obtained;
- (e) extruding said paste;
- (f) drying the extrudate;
- and
- (g) calcining the dried extrudate under an oxidizing atmosphere, wherein the axial breaking strength of the catalyst ranges from 99 kg/cm2 to 280 kg/cm2.
9 more elements
A process of preparing an extruded catalyst consisting of a catalytically active portion of silica/alumina gel having a silica/alumina molar ratio ranging from 50:1 to 500:1 dispersed in an inert binder agent, which is obtained by:
- (a) preparing an aqueous solution of a tetraalkylammonium hydroxide (TAA—OH), a soluble aluminum compound capable of yielding Al2O3 by hydrolysis and a silicon compound capable of yielding SiO2 by hydrolysis, in the following mutual molar ratios:
- SiO2:Al2O3=from 50:1 to 500:1
- TAA—OH:SiO2=from 0.05:1 to 0.2:1
- H2O:SiO2 from 5:1 to 40:1;
- (b) heating the resulting solution (a) in order to effect hydrolysis and gelation of the components of solution (a) thereby obtaining mixture (A) having a viscosity within the range of from 0.01 to 100 Pa sec;
- (c) adding to said mixture (A), firstly a binding agent selected from the group consisting of a boehmite and a pseudo-boehmite, in a ratio, by weight, to said mixture (A) within the range of from 0.05 to 0.5, followed by a plasticizer, and then adding an organic acid in an amount within the range of from 0.5 to 8 g per 100 g of binding agent;
- (d) mixing the combined material of step (c) and heating the mixture to a temperature within the range of from 40 to 90° C. until a homogeneous paste is obtained;
- (e) extruding said paste;
- (f) drying the extrudate;
- and
- (g) calcining the dried extrudate under an oxidizing atmosphere, wherein the axial breaking strength of the catalyst ranges from 99 kg/cm2 to 280 kg/cm2.
8 more elements
Dependencies are inferred from the claim text.