Nickel-based mesoporous catalyst and use thereof in hydrogenation

Patent metadata

Field	Value
Publication number	US-2017259249-A1
Application number	US-201515509873-A
Country	US
Kind code	A1
Filing date	Aug 21, 2015
Priority date	Sep 11, 2014
Publication date	Sep 14, 2017
Grant date	—

Abstract

A supported catalyst having a calcined, predominantly aluminium, oxide support and an active phase of 5 to 65% by weight nickel with respect to the total mass of the catalyst, said active phase having no group VIB metal, the nickel particles having a diameter less than or equal to 20 nm, said catalyst having a mesopore median diameter greater than or equal to 14 nm, a mesopore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a total pore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a macropore volume less than 5% of the total pore volume, said catalyst being in the form of grains having an average diameter comprised between 0.5 and 10 mm. The invention also relates to the process for the preparation of said catalyst and the use thereof in a hydrogenation process.

First claim

1 . Supported catalyst comprising a calcined, predominantly aluminium, oxide support and an active phase comprising nickel, the nickel content being comprised between 5 and 65% by weight of said element with respect to the total mass of the catalyst, said active phase comprising no group VIB metal, the nickel particles having a diameter less than or equal to 20 nm, said catalyst having a mesopore median diameter greater than or equal to 14 nm, a mesopore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a total pore volume measured by mercury porosimetry greater than or equal to 0.45 mL/g, a macropore volume less than 5% of the total pore volume, said catalyst being in the form of grains having an average diameter comprised between 0.5 and 10 mm.

2 . Catalyst according to claim 1 , in which the mesopore median diameter of the catalyst is comprised between 18 and 25 nm.

3 . Catalysts according to claim 1 , in which the mesopore volume of the catalyst is comprised between 0.55 ml/g and 0.95 ml/g.

4 . Catalyst according to claim 1 , in which the macropore volume of the catalyst is less than 3.5% of the total pore volume.

5 . Catalyst according to claim 1 , in which the nickel content is comprised between 10 and 34% by weight of said element with respect to the total mass of the catalyst.

6 . Catalyst according to claim 1 , containing no pores with a diameter comprised between 2 and 7 nm.

7 . Catalyst according to claim 1 , containing no micropores.

8 . Process for the preparation of a catalyst according to claim 1 comprising the following steps:
a) a first step of precipitation, in an aqueous reaction medium, of at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonium hydroxide, 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 is selected so as to obtain a pH of the reaction medium comprised between 8.5 and 10.5 and the flow rate of the acidic and basic precursor(s) containing aluminium is adjusted so as to obtain a degree of progression of the first step comprised between 5 and 13%, the degree of progression being defined as the proportion of alumina formed in Al 2 O 3 equivalent during said first step of precipitation with respect to the total quantity of alumina formed in Al 2 O 3 equivalent at the end of step c) of the preparation process, said step taking place at a temperature comprised between 20 and 90° C. and for a duration comprised between 2 and 30 minutes;
b) a step of heating the suspension obtained in step a) at a temperature comprised between 40 and 90° C. for a duration comprised between 7 and 45 minutes in order to obtain an alumina gel,
c) a second step of precipitation of the suspension obtained at the end of heating step b) by adding, to the suspension, at least one basic precursor selected from sodium aluminate, potassium aluminate, ammonium hydroxide, 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 is selected so as to obtain a pH of the reaction medium comprised between 8.5 and 10.5 and the flow rate of the acidic and basic precursor(s) containing aluminium is adjusted so as to obtain a degree of progression of the second step comprised between 87 and 95%, the degree of progression being defined as the proportion of alumina formed in Al 2 O 3 equivalent during said second precipitation step with respect to the total quantity of alumina formed in Al 2 O 3 equivalent at the end of step c) of the preparation process, said step taking place at a temperature comprised between 40 and 90° C. and for a duration comprised between 2 and 50 minutes;
d) a step of filtration of the suspension obtained at the end of second precipitation step c) in order to obtain an alumina gel,
e) a step of drying said alumina gel obtained in step d) in order to obtain a powder, f) a step of forming the powder obtained at the end of step e) in order to obtain a crude material,
g) a step of heat treatment of the crude material obtained at the end of step f) at a temperature comprised between 500 and 1000° C., in the presence or absence of an air flow containing up to 60% by volume of water, in order to obtain a calcined aluminium oxide support;
h) a step of impregnation of said support with a solution comprising the salt(s) of the precursor(s) of the nickel-based active phase;
i) a step of drying said impregnated support at a temperature comprised between 15 and 250° C. so as to obtain a dried catalyst,
j) optionally a heat treatment of said dried catalyst at a temperature comprised between 250 and 1000° C., in the presence or absence of water.

9 . Process according to claim 8 , in which at least one reducing treatment step k) is carried out in the presence of a reducing gas after steps i) or j) so as to obtain a catalyst comprising nickel at least partially in metallic form.

10 . Process according to claim 9 , in which a passivation step 1) is carried out with a sulphur- or oxygen-containing compound, or with CO 2 before or after reducing treatment step k).

11 . Process according to claim 8 , in which the degree of progression of the first precipitation step a) is comprised between 6 and 12%.

12 . Process according to claim 8 , in which the acidic precursor of steps a) and c) is selected from aluminium sulphate, aluminium chloride and aluminium nitrate, and in which the basic precursor of steps a) and c) is selected from sodium aluminate and potassium aluminate.

13 . Hydrogenation process in which the catalyst according to claim 1 brought into contact, in the presence of hydrogen, with a feedstock of hydrocarbons containing polyunsaturated and/or aromatic compounds so as to obtain an at least partially hydrogenated effluent.

14 . Hydrogenation process according to claim 13 in which a selective hydrogenation is carried out at a temperature comprised between 0 and 500° C., at a pressure comprised between 0.1 and 20 MPa, at a hydrogen/(polyunsaturated compounds to be hydrogenated) molar ratio between 0.1 and 10 at an hourly space velocity HSV comprised between 0.1 and 200 h −1 for a liquid feedstock, comprised between 100 and 15,000 h −1 for a gaseous feedstock, of a hydrocarbon feedstock containing polyunsaturated compounds containing at least 2 carbon atoms per molecule and having a final boiling point less than or equal to 250° C.

15 . Hydrogenation process according to claim 13 in which a hydrogenation of the aromatics is carried out at a temperature comprised between 30 and 350° C., at a pressure comprised between 0.1 and 20 MPa, at a hydrogen/(aromatic compounds to be hydrogenated) molar ratio between 0.1 and 10 and at an hourly space velocity HSV comprised between 0.05 and 50 h −1 , of a hydrocarbon feedstock containing aromatic compounds and having a final boiling point less than or equal to 650° C.

Assignees

• Ifp Energies Now

Inventors

• Boualleg Malika
• Dubreuil Anne-Claire
• Maille Emily
• Thomazeau Cecile

Classifications

• B01J37/009

  Preparation by separation, e.g. by filtration, decantation, screening · CPC title

• B01J37/0236

  Drying, e.g. preparing a suspension, adding a soluble salt and drying · CPC title

• B01J37/0205

  in several steps · CPC title

• B01J37/036

  to form a gel or a cogel · CPC title

• C01F7/34

  Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts · CPC title