# US 2018/0021754 A1 · Methods for the preparation of alumina beads formed by dewatering a highly dispersible gel

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- Number: US 2018/0021754 A1
- Document ID: US20180021754A1
- Status: Published application
- Kind: A1
- Application number: 15/537,794
- Filed: 2015-12-16
- Published: 2018-01-25
- Earliest claimed: 2014-12-18
- Assignees: Ifp Energies Nouvelles
- Applicants: IFP Energies nouvelles
- Inventors: Malika BOUALLEG; Aurelie DANDEU
- Web page: https://patentgrep.com/patent/US20180021754A1

## CPC

- B01J 21/04: Alumina
- B01J 20/08: comprising aluminium oxide or hydroxide; comprising bauxite
- B01J 20/28016: {Particle form}
- B01J 20/28057: {Surface area, e.g. B.E.T specific surface area}
- B01J 20/28069: {Pore volume, e.g. total pore volume, mesopore volume, micropore volume}
- B01J 20/28078: {Pore diameter}
- B01J 23/38: of noble metals
- B01J 23/40: of the platinum group metals
- B01J 27/135: with titanium, zirconium, hafnium, germanium, tin or lead
- B01J 35/19: {Catalysts containing parts with different compositions}
- B01J 35/615: {100-500 m2/g}
- B01J 37/0018: {Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)}
- B01J 37/0072: {Preparation of particles, e.g. dispersion of droplets in an oil bath}
- B01J 37/009: {Preparation by separation, e.g. by filtration, decantation, screening}
- B01J 37/031: {Precipitation}
- B01J 37/08: Heat treatment {(B01J37/0009, B01J37/0018 take precedence)}
- C01F 7/141: from aqueous aluminate solutions by neutralisation with an acidic agent
- C01F 7/34: Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts
- C01F 7/44: Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water
- C01F 7/441: by calcination
- C10G 35/06: characterised by the catalyst used
- C10G 35/085: containing platinum group metals or compounds thereof
- B01J 35/37: Crush or impact strength
- B01J 35/45: Nanoparticles
- B01J 35/51: Spheres
- B01J 35/635: {0.5-1.0 ml/g}
- B01J 35/647: {2-50 nm}
- B01J 35/77: Compounds characterised by their crystallite size
- B01J 2235/15: X-ray diffraction
- C01P 2002/02: Amorphous compounds
- C01P 2004/32: Spheres
- C01P 2006/12: Surface area
- C01P 2006/14: Pore volume
- C01P 2006/17: Pore diameter distribution
- C01P 2006/22: Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
- C01P 2006/80: Compositional purity
- C10G 2400/02: Gasoline
- 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})
- C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

A process for the preparation of an alumina in the form of beads with a sulphur content in the range 0.001% to 1% by weight and a sodium content in the range 0.001% to 1% by weight with respect to the total mass of said beads is described, said beads being prepared by shaping an alumina gel having a high dispersibility by drop coagulation. The alumina gel is itself prepared using a specific precipitation preparation process in order to obtain at least 40% by weight of alumina with respect to the total quantity of alumina formed at the end of the gel preparation process right from the first precipitation step, the quantity of alumina formed at the end of the first precipitation step possibly even reaching 100%. The invention also concerns the use of alumina beads as a catalyst support in a catalytic reforming process.

## Claims

### Claim 1

A process for the preparation of an alumina in the form of beads with a sulphur content in the range 0.001% to 1% by weight and a sodium content in the range 0.001% to 1% by weight with respect to the total mass of said beads, said process comprising at least the following steps:
a) at least one first step for the precipitation of alumina, in an aqueous reaction medium, using at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonia, sodium hydroxide and potassium hydroxide and at least one acidic precursor selected from aluminium sulphate, aluminium chloride, aluminium nitrate, sulphuric acid, hydrochloric acid and nitric acid, in which at least one of the basic or acidic precursors comprises aluminium, the relative flow rate of the acidic and basic precursors being selected in a manner such as to obtain a pH of the reaction medium in the range 8.5 to 10.5 and the flow rate of the acidic and basic precursor or precursors containing aluminium being regulated in a manner such as to obtain a percentage completion of said first step in the range 40% to 100%, the percentage completion being defined as being the proportion of alumina formed in equivalents of Al2O3 during said first precipitation step with respect to the total quantity of alumina formed at the end of the precipitation step or steps, said first precipitation step being operated at a temperature in the range 10° C. to 50° C., and for a period in the range 2 minutes to 30 minutes;
b) a step for heat treatment of the suspension obtained at the end of step a) at a temperature in the range 50° C. to 200° C. for a period in the range 30 minutes to 5 hours in order to obtain an alumina gel;
c) a step for filtration of the suspension obtained at the end of the heat treatment step b) followed by at least one step for washing the gel obtained;
d) a step for drying the alumina gel obtained at the end of step c) in order to obtain a powder;
e) a step for shaping the powder obtained at the end of step d) by drop coagulation in order to obtain the green material;
f) a step for heat treatment of the green material obtained at the end of step e) at a temperature in the range 500° C. to 1000° C., in the presence or absence of a stream of air containing up to 60% by volume of water.

### Claim 2 (depends on 1)

The process according to claim 1, in which the basic precursor is sodium aluminate.

### Claim 3 (depends on 1)

The process according to claim 1, in which the acidic precursor is aluminium sulphate.

### Claim 4 (depends on 1)

The process according to claim 1, in which the percentage completion of said precipitation step a) is in the range 45% to 90%.

### Claim 5 (depends on 1)

The process according to claim 1, in which in the case in which the percentage completion obtained at the end of the first precipitation step a) is less than 100%, said preparation process comprises a second precipitation step a′) after the first precipitation step.

### Claim 6 (depends on 5)

The process according to claim 5, in which a step for heating the suspension obtained at the end of the precipitation step a) is carried out between the two precipitation steps a) and a′), said heating step being operated at a temperature in the range 20° C. to 90° C. for a period in the range 7 to 45 minutes.

### Claim 7 (depends on 5)

The process according to claim 5, in which said second step a′) for precipitation of the suspension obtained at the end of the heating step is operated by adding to said suspension at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonia, sodium hydroxide and potassium hydroxide and of at least one acidic precursor selected from aluminium sulphate, aluminium chloride, aluminium nitrate, sulphuric acid, hydrochloric acid and nitric acid, in which at least one of the basic or acidic precursors comprises aluminium, the relative flow rate of the acidic and basic precursors being selected in a manner such as to obtain a pH of the reaction medium in the range 8.5 to 10.5 and the flow rate of the acidic and basic precursor or precursors containing aluminium being regulated in a manner such as to obtain a percentage completion of the second step in the range 0 to 60%, the percentage completion being defined as being the proportion of alumina formed in equivalents of Al2O3 equivalents during said second precipitation step a′) with respect to the total quantity of alumina formed at the end of step a′) of the preparation process, said step being operated at a temperature in the range 40° C. to 90° C., and for a period in the range 2 minutes to 50 minutes.

### Claim 8 (depends on 1)

The process according to claim 1, in which said step e) for shaping by drop coagulation comprises preparing a suspension comprising the dried powder, a pore-forming agent selected from greases, oils and mineral waxes, fats, hydrocarbons and oil cuts, a surfactant selected from non-ionic surfactants or ionic surfactants and water, with stirring.

### Claim 9 (depends on 8)

The process according to claim 8, in which the quantity of pore-forming agent, expressed as the ratio of the mass of pore-forming agent to the total mass of alumina expressed as the percentage of Al2O3 engaged in the suspension, is in the range 0.2% to 60%.

### Claim 10 (depends on 8)

The process according to claim 8, in which the proportion of surfactant present in the emulsion, defined as being equal to the ratio of the mass of surfactant to the mass of pore-forming agent, is in the range 1% to 25% by weight.

### Claim 11 (depends on 8)

The process according to claim 8 in which, during the preparation of the suspension comprising the dried powder, a charge of alumina or of alumina precursor is added to a quantity of charge, expressed as the % by weight of Al2O3, of less than or equal to 30% by weight with respect to the total weight of the suspension in equivalents of Al2O3.

### Claim 12 (depends on 1)

Alumina beads with a sulphur content in the range 0.001% to 1% by weight, and a sodium content in the range 0.001% to 1% by weight with respect to the total mass of said beads which are capable of being obtained by a process according to claim 1.

### Claim 13 (depends on 12)

Alumina beads according to claim 12, having a BET specific surface area of more than 220 m2/g.

### Claim 14 (depends on 1)

A process for the catalytic reforming of a hydrocarbon feed comprising n-paraffinic, naphthenic and aromatic hydrocarbons, using a catalyst comprising at least one or more metals selected from group VIII of the periodic classification and a support comprising amorphous mesoporous alumina beads prepared in accordance with the preparation process according to claim 1, said process being operated at a temperature in the range 400° C. to 700° C., a pressure in the range 0.1 to 4 MPa and a mass flow rate of feed treated per unit mass of catalyst per hour in the range 0.1 to 10h −1.