Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Sulfur or compound containing same
Reexamination Certificate
1999-06-25
2001-11-13
Wood, Elizabeth D. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Sulfur or compound containing same
C502S217000, C502S219000, C502S220000, C502S221000, C502S222000, C502S223000, C502S208000, C502S210000, C502S211000, C502S202000, C502S203000, C502S204000, C502S206000, C502S207000
Reexamination Certificate
active
06316382
ABSTRACT:
The present invention relates to a process for the sulfurization of supported hydrocracking or hydroconversion catalysts containing at least one element selected from group IIB, including the lanthanides and actinides, group IVB, group VB and group VIB (groups 3, 4, 5 and 6 in the new notation for the periodic table: “Handbook of Chemistry and Physics, 76
th
edition, 1995-1996, inside front cover), associated with at least one porous matrix, generally an amorphous or low crystallinity oxide type matrix, optionally at least one zeolitic or non zeolitic molecular sieve, optionally at least one element selected from group VIII (groups 8, 9, 10 in the new notation for the periodic table), optionally at least one element selected from the group formed by P, B, Si, and optionally at least one element from group VIIA (group 17). The process for preparing the sulphurised catalyst is characterized in that the a prior reduction step is carried out using at least one reducing gas other than hydrogen before carrying out a sulphurisation step using any method which is known to the skilled person.
The present invention also relates to the catalysts obtained using the process of the present invention.
The present invention also relates to the use of the sulphide catalysts obtained as catalysts for hydrorefining or hydroconversion of hydrocarbon-containing feeds containing at least one aromatic and/or olefinic and/or naphthenic and/or paraffinic type compound, said feeds possibly containing metals and/or nitrogen and/or oxygen and/or sulphur.
The sulphides can be synthesised by a number of methods which are well known to the skilled person.
Crystallised transition metal or rare earth sulphides can be synthesised by reacting transition metal or rare earth type elements with elemental sulphur at high temperature in a process which its well known to the skilled person in the solid state chemistry field but is expensive, in particular as regards industrial application.
The synthesis of bulk or supported sulphides by reacting a suitable precursor in the form of a mixed oxide of transition metals or rare earth metals with a sulphur compound in a gas phase such as hydrogen sulphide or carbon disulphide, CS
2
, or mercaptans, sulphides, disulphides, hydrocarbon-containing polysulphides, sulphur vapour, COS, carbon disulphide, in a traversed bed reactor, is well known to the skilled person.
The synthesis of sulphides by reacting a suitable precursor in the form of a mixed oxide of transition metals and/or rare earths impregnated with a sulphur compound in the liquid phase followed by treatment in hydrogen in a traversed bed reactor is well known to the skilled person.
The synthesis of bulk sulphide catalysts or sulphide catalysts supported on a porous matrix by treatment of a bulk oxide precursor or an oxide precursor supported on a porous matrix in hydrogen with a sulphur-containing hydrocarbon feed, in particular sulphur-containing petroleum cuts such as gasoline, kerosene, gas oil, to which a sulphur compound, for example dimethyldisulphide, can optionally be added, is also well known to the skilled person.
Bulk sulphides can also be synthesised by co-precipitation, in a basic medium, of sulphur-containing complexes in solution containing two cations. This method can be carried out at a controlled pH and is termed homogeneous sulphide precipitation. It has been used to prepare a mixed sulphide of cobalt and molybdenum (G. Hagenbach, P. Courty, B. Delmon, Journal of Catalysis, volume 31, page 264, 1973).
Synthesising bulk mixed sulphides on a porous matrix by treatment of a bulk oxide precursor or an oxide precursor supported on a porous matrix in a hydrogen/hydrogen sulphide mixture or nitrogen/hydrogen sulphide mixture is also well known to the skilled person.
United States patent U.S. Pat. No. 4,491,639 describes the preparation of a sulphur-containing compound by reacting elemental sulphur with V, Mo and W salts and in particular V, Mo and W sulphides optionally containing at least one of elements from the series C, Si, B, Ce, Th, Nb, Zr, Ta and U in combination with Co or Ni.
Other methods have been proposed for the synthesis of simple sulphides. As an example, the synthesis of crystallised simple sulphides of rare earths described in U.S. Pat. No. 3,748,095 and French patent FR-A-2 100 551 proceeds by reacting hydrogen sulphide or carbon disulphide with an amorphous rare earth oxide or oxycarbonate at a temperature of over 1000° C.
European patents EP-A-0 440 516 and U.S. Pat. No. 5,279,801 describe a process for synthesizing simple transition metal or rare earth sulphur-containing compounds by reacting a transition metal or rare earth compound with a carbon-containing sulphur compound in the gaseous state, in a closed vessel at a moderate temperature of 350° C. to 600° C.
However, it is well known that certain elements such as group IIIB elements, including the lanthanides and actinides, group IVB elements, and group VB elements, in a bulk oxide form are very difficult to sulphurise. The known sulphurisation methods which are routinely used industrially and in the laboratory, such as sulphurisation in a gaseous hydrogen/hydrogen sulphide mixture or liquid phase sulphurisation under hydrogen pressure using a mixture of a hydrocarbon feed and a sulphur-containing compound such as dimethyldisulphide, are thus ineffective when sulphurising such solids.
The considerable amount of research carried out by the Applicant on preparing sulphide catalysts based on sulphides of elements from groups IIIB, IVB and VB and numerous other elements of the periodic table, used alone or as mixtures, associated with a matrix, have led to the discovery that, surprisingly, if a treatment in a reducing gas other than hydrogen is carried out prior to sulphurisation, the activity of the catalysts is improved. Without wishing to be bound by any particular theory, it appears that sulphurisation of a catalyst which has been moderately pre-reduced by a reducing gas other than hydrogen results in better sulphurisation and better dispersion of the sulphide phase.
The invention relates to preparing sulphide catalysts, characterized in that a prior reduction step is carried out using at least one reducing gas other than hydrogen before carrying out the sulphurisation step.
More precisely, a process for producing the sulphide catalysts of the present invention comprises the following steps:
a) preparing a catalyst which comprises at least one element selected from group IIIB, including the lanthanides and actinides, group IVB, group VB and group VIB, at least one porous matrix which is generally an amorphous or low crystallinity oxide type matrix, optionally associated with at least one zeolitic or non zeolitic molecular sieve, optionally at least one group VIII element, optionally at least one element selected from the group formed by P, B and Si, optionally at least one anion from group VIIA, optionally carbon, and optionally water;
b) carrying out a reducing treatment on the catalyst prepared in step a) by exposing it to a gas or a mixture of reducing gases other than hydrogen in a reactor at a heating temperature of more than 40° C. at a pressure of over 0.01 MPa;
c) sulphurising the catalyst by exposing the reduced catalyst obtained in step b) to a solid, liquid or gaseous sulphurising agent at a temperature in the range 40° C. to 1000° C. and at a pressure of over 0.01 MPa.
The reactor may be a closed reactor. In this case, it may be charged in the open air and after sealing, it may be purged with an inert gas such as argon or helium and the reducing gas is introduced. After reaction, the pressure exerted is the pressure due to the gases produced by the reactions and to the residual reducing gas.
The reactor can be a traversed bed reactor, such as a fixed bed, moving bed, ebullated bed, or fluidised bed reactor. In this case the pressure exerted is that of the reducing gas.
Catalyst sulphurisation can also be carried out ex-situ, for example outside the location where the catalyst is used.
The reaction of step b) is car
Institut Francais du Pe'trole
Millen White Zelano & Branigan P.C.
Wood Elizabeth D.
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