# US 11,110,431 B2 · Alumina having acidity and structure with a porosity which are optimal

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- Number: US 11,110,431 B2
- Document ID: US11110431B2
- Status: Granted
- Kind: B2
- Application number: 16/521,813
- Filed: 2019-07-25
- Published: 2020-01-30
- Granted: 2021-09-07
- Earliest claimed: 2018-07-25
- Assignees: Axens
- Applicants: Axens
- Inventors: Christophe Nedez; Olivier Ducreux
- Web page: https://patentgrep.com/patent/US11110431B2

## CPC

- B01J 21/04: Alumina
- B01J 20/08: comprising aluminium oxide or hydroxide; comprising bauxite
- B01J 20/28059: {being less than 100 m2/g}
- B01J 20/28061: {being in the range 100-500 m2/g}
- B01J 20/28071: {being less than 0.5 ml/g}
- B01J 20/28073: {being in the range 0.5-1.0 ml/g}
- B01J 23/04: Alkali metals
- B01J 23/92: of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J 35/613: {10-100 m2/g}
- B01J 35/615: {100-500 m2/g}
- B01J 35/633: {less than 0.5 ml/g}
- B01J 35/635: {0.5-1.0 ml/g}
- B01J 35/647: {2-50 nm}
- B01J 35/651: {50-500 nm}
- B01J 37/0063: {Granulating}
- B01J 37/0072: {Preparation of particles, e.g. dispersion of droplets in an oil bath}
- B01J 37/08: Heat treatment {(B01J37/0009, B01J37/0018 take precedence)}
- C01F 7/441: by calcination
- C01F 7/46: Purification of aluminium oxide, aluminium hydroxide or aluminates (C01F7/028 takes precedence)
- C07C 1/24: by elimination of water
- C01P 2006/12: Surface area
- C01P 2006/14: Pore volume
- C01P 2006/17: Pore diameter distribution
- C01P 2006/80: Compositional purity
- C07C 2521/04: Alumina
- Y02P 20/52: using catalysts, e.g. selective catalysts
- Y02P 20/584: Recycling of catalysts
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00})
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

An alumina exhibiting a structure with a porosity such that the volume of the pores having a diameter of between 70 and 2000 Å is between 0.15 and 0.50 ml/g, and comprising at least one alkali metal (M), such that the content by weight of alkali metal, expressed as M2O, is between 400 and 1500 ppm, with respect to the total weight of the alumina, and a process for the transformation of a feedstock comprising at least one alcohol into an olefinic effluent, said process comprising a stage of dehydration of said alcohol in the presence of the alumina according to the present invention, having an acidity and a structure with a porosity which are optimal.

## Claims

### Claim 1

An alumina exhibiting a structure with a porosity such that the content of pores having a diameter of between 70 and 2000 Å is between 0.15 and 0.50 ml/g, and comprising at least one alkali metal (M), such that the content by weight of alkali metal, expressed as M2O, is between 400 and 1500 ppm, with respect to the total weight of the alumina, wherein the alumina exhibits a BET specific surface area of at least 150 m2/g and wherein the alumina contains at most 500 ppm by weight of silica, expressed as SiO2.

### Claim 2 (depends on 1)

The alumina according to claim 1, in which the volume of the pores having a diameter of between 70 and 2000 Å is greater than or equal to 0.20 ml/g, and less than or equal to 0.40 ml/g.

### Claim 3 (depends on 1)

The alumina according to claim 1, in which the content by weight of alkali metal, expressed as M2O, is between 400 and 950 ppm, with respect to the total weight of the alumina.

### Claim 4 (depends on 1)

The alumina according to claim 1, in which the total pore volume is greater than or equal to 0.50 ml/g.

### Claim 5 (depends on 1)

The alumina according to claim 1, exhibiting a volume of the pores with a diameter of greater than or equal to 70 Å, denoted V70 Å, of greater than or equal to 0.35 ml/g.

### Claim 6 (depends on 1)

The alumina according to claim 1, exhibiting a BET specific surface area of at least 200 m2/g, and of at most 350 m2/g.

### Claim 7 (depends on 1)

The alumina according to claim 1, containing at most 100 ppm by weight of silica, expressed as SiO2.

### Claim 8 (depends on 1)

The alumina according to claim 1, having a structure comprising χ-alumina and amorphous alumina.

### Claim 9 (depends on 1)

The alumina according to claim 1, containing strictly less than 80% by weight of γ-alumina.

### Claim 10 (depends on 1)

The alumina according claim 1, containing strictly less than 35% by weight of η-alumina.

### Claim 11 (depends on 1)

The alumina according to claim 1, obtained by rapid dehydration of an aluminium hydroxide or oxyhydroxide.

### Claim 12 (depends on 1)

A process for the transformation of a feedstock comprising at least one alcohol into an olefinic effluent, said process comprising a stage of dehydration of said alcohol in the presence of the alumina according to claim 1.

### Claim 13 (depends on 12)

The process according to claim 12, in which the feedstock comprises at least 50% by weight of alcohol, with respect to the weight of said feedstock.

### Claim 14 (depends on 12)

The process according to claim 12, in which said alcohol comprises from 3 to 9 carbon atoms.

### Claim 15 (depends on 12)

The process according to claim 12, in which said alcohol is a secondary and/or tertiary alcohol.

### Claim 16 (depends on 12)

The process according to claim 12, in which the dehydration stage comprises a reaction section in which the dehydration reaction is carried out in the gas phase, in the liquid phase or in a mixed phase, at a temperature of between 200° C. and 450° C., at a pressure of between 0.1 and 4 MPa and with an hourly space velocity (HSV) of between 0.5 h−1 and 10 h−1.