RU2299095C2 - Method of regenerating exhausted oil feedstock hydrofining catalyst - Google Patents

Abstract

FIELD: petrochemical process catalysts.

SUBSTANCE: invention, in particular, relates to catalysts based on nickel, cobalt, molybdenum, aluminum oxides. Regeneration of exhausted catalyst is carried out through heat treatment in air atmosphere at 550-600°C for 1-1.5 h followed by: mechanical activation at energy concentration at least 6.6 W/g on vibrational mill; grinding into powder; adding at stirring a mixture containing nitric acid solution (concentration 3,5-7%), cobalt or nickel nitrate and ammonium paramolybdate; molding; drying; and calcination.

EFFECT: simplified regeneration procedure and enabled restoration of catalyst strength.

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Description

The invention relates to the refining, petrochemicals and production of ammonia, methanol and hydrogen, in particular to a method for the regeneration of spent alumina-cobalt-molybdenum and alumina-nickel-molybdenum catalysts for the hydrotreating of petroleum feedstocks, natural and process gases.

A known method of regeneration of catalysts based on oxides of nickel, cobalt, molybdenum, aluminum, silicon for hydrotreating petroleum feeds by grinding spent catalyst into powder, processing with 10-20% nitric acid solution, molding, sinking for 24 hours, drying at 120-150 ° C for 6-12 hours, calcining at 500-550 ° C for 6-12 hours, followed by stepwise processing of the obtained granules with solutions of salts of ammonium molybdenum acid and cobalt or nickel nitrate, with intermediate drying and calcining at 500-550 ° C for6-12 hours (SU 738660, B 01 J 23/94, 1980).

The disadvantage of this method is a multi-stage, energy-intensive technology, which leads to a high cost of regeneration of the catalyst.

The closest in technical essence and the achieved result is a method of regeneration of spent catalysts for hydrotreating petroleum feedstocks based on nickel, cobalt, molybdenum, aluminum, silicon oxides, including grinding the catalyst into a powder, cobalt or nickel nitrate salt is added to it with stirring, the resulting mixture is processed 10-20% nitric acid, then a salt of ammonium molybdenum acid is added to it, followed by molding, drying, drying at 120-160 ° С, calcination at 500-550 ° С (SU 825136, B 01 J 23/94, 19 81).

The disadvantage of this method is the complex technology of introducing active components with a large amount of concentrated nitric acid, which leads to the release of significant amounts of nitrogen oxides during calcination, the presence of a stage of drying leads to a decrease in the productivity of the equipment.

The task of the invention is to restore the activity and strength of spent catalysts based on nickel, cobalt, molybdenum and aluminum oxides used for hydrotreating petroleum feedstocks, simplifying the technology of the regeneration process.

This object is achieved in that the spent catalyst for hydrotreating oil is subjected to heat treatment in furnaces in an atmosphere of air at a temperature of 550-600 ° C for 1-1.5 hours, then the granules are subjected to mechanical activation with an energy intensity of at least 6.6 W / g by grinding in a vibratory mill, to a grinding fineness of more than 100 μm, 10–20%, a mixture containing 3.5–7% concentration of a solution of nitric acid and salts of cobalt or nickel nitrate and ammonium paramolybdate is introduced into the milled catalyst before stirring, and then catalyst mass is formed, dried and calcined.

The essence of the proposed method of regeneration in comparison with the known one consists in the following: heat treatment of granules of fully or partially spent catalyst at a temperature of 550-600 ° C allows you to remove unwanted impurities in the form of carbon deposits and organic compounds, which leads to an increase in activity, allows mechanical activation of the regenerated catalyst in vibration-type mills characterized by shock-abrasive action; mechanical activation (the method of directional regulation of the physicochemical properties of solids and the creation of defective structures under the action of supplied mechanical energy) at the stage of grinding the granules reduces the concentration of nitric acid, eliminates the stage of drying, and obtain a catalyst with high activity and strength; introducing into the regenerated catalyst a mixture of nitric acid with salts of cobalt nitrate or nickel and ammonium paramolybdate can increase the activity of the catalyst due to the formation of new active centers.

This method allows you to fully restore the activity and strength of the spent catalysts based on cobalt, nickel, molybdenum and aluminum oxides used for hydrotreating petroleum feedstocks, as well as simplify the technology of the regeneration process.

The proposed method is as follows.

The spent catalyst based on nickel, cobalt, molybdenum and aluminum oxides is subjected to heat treatment in an atmosphere of air at a temperature of 550-600 ° C for 1-1.5 hours, then it is loaded into a vibrating mill and grinding is performed with energy intensity (specific consumption of input energy) of at least 6.6 W / g to a fineness of grinding of more than 100 μm 10-20%. The resulting powder is loaded into the mixer and treated with stirring for 0.5-1 hours with a mixture containing 3.5-7% concentration of nitric acid, cobalt nitrate or nickel and ammonium paramolybdate. The resulting mass is molded, dried at a temperature of 100-110 ° C for 0.5-1 hours and calcined at a temperature of 450-500 ° C for 2 hours.

Example 1. 150 kg of spent, lost its activity industrial catalyst of chemical composition, wt.% CoO - 3.8; MoO ₃ -11.3; C is 4.6; Al ₂ O ₃ - the rest is subjected to heat treatment in an atmosphere of air at a temperature of 550 ° C for 1.5 hours, loaded into a vibrating mill and grinding (mechanical activation) with an energy intensity of 9.5 W / g to a fineness of grinding fractions of more than 100 μm 10%.

Then 130 kg of powder are loaded into the mixer and treated with a mixture containing 60 liters of a 3.5% solution of nitric acid, 1.66 kg of ammonium paramolybdate and 2.6 kg of cobalt nitrate for 0.5 hours.

The resulting mass with a moisture content of 28% is molded, dried on a dryer at a temperature of 100-110 ° C for 0.5-1 hours and calcined at a temperature of 500 ° C for 2 hours.

Ready catalyst chem. composition, wt.%:

CoO 4.3

MoO ₃ 12.3

C 0.04

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.95 kg / mm.

Example 2. 150 kg of spent lost its activity of industrial Al-Co-Mo catalyst chemical composition of example 1 is subjected to heat treatment in an atmosphere of air at 600 ° C for 1 hour and grinding in the conditions of example 1 to a fineness of grinding of more than 100 μm 20%.

Then 130 kg of powder are loaded into the mixer and treated with a mixture containing 60 liters of a 3.5% solution of nitric acid, 4.98 kg of ammonium paramolybdate and 5.2 kg of cobalt nitrate for 0.5 hours. Further processing is carried out under the conditions of example 1.

Calcination is carried out in an oven at a temperature of 450 ° C for 2 hours. Ready catalyst chem. composition, wt.%:

CoO 4.8

MoO ₃ 14.3

C 0.02

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 2.2 kg / mm.

Example 3.150 kg of spent industrial Al-Co-Mo catalyst that has lost its activity of the chemical composition of Example 1 is subjected to heat treatment under the conditions of Example 1 and grinding with an energy intensity of 6.6 W / g in a vibration mill to a fineness of grinding fractions of more than 100 μm 10%.

Then 130 kg of powder are loaded into the mixer and treated with a mixture of 60 liters of a 7% concentration of nitric acid solution, 4.98 kg of ammonium paramolybdate and 5.2 kg of cobalt nitrate. Further processing is carried out under the conditions of example 1.

Ready catalyst chem. composition, wt.%:

CoO 4.8

MoO ₃ 14.3

C 0.04

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 2.35 kg / mm.

Example 4. 150 kg of spent lost its activity of an industrial Al-Co-Mo catalyst of chemical composition according to example 1 is subjected to heat treatment in an atmosphere of air at a temperature of 600 ° C for 1 hour and grinding in the conditions of example 1 to fineness grinding fractions of more than 100 μm 15% .

Then 130 kg of powder are loaded into the mixer and treated with a mixture containing 60 liters of a 7% concentration of nitric acid solution, 1.66 kg of ammonium paramolybdate and 2.6 kg of cobalt nitrate. Further processing is carried out under the conditions of example 1.

Calcination is carried out in a SKZ furnace at a temperature of 450 ° C for 2 hours.

Ready catalyst chem. composition, wt.%:

CoO 4.3

MoO ₃ 12.3

C 0.04

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 2.3 kg / mm.

Example 5. 150 kg of spent lost its activity industrial Al-Ni-Mo catalyst of chemical composition, wt.%: NiO - 4.1; MoO ₃ - 12.0; C is 2.1; Al ₂ O ₃ - the rest is subjected to heat treatment in an atmosphere of air at a temperature of 550 ° C for 1.5 hours and grinding with an energy intensity of 6.6 W / g in a vibratory mill to a fineness of grinding fractions of more than 100 μm 20%.

Then 130 kg of powder are loaded into the mixer and treated with a mixture containing 60 liters of a 3.5% concentration of nitric acid solution, 4.98 kg of ammonium paramolybdate and 5.2 kg of nickel nitrate. Further processing is carried out under the conditions of example 1. Calcination is carried out in an oven at a temperature of 500 ° C for 2 hours.

Ready catalyst chem. composition, wt.%:

NiO 5.1

MoO ₃ 13.5

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 2.3 kg / mm.

Example 6. 150 kg of spent, lost its activity industrial catalyst of chemical composition according to example 5 is subjected to heat treatment in an atmosphere of air at a temperature of 600 ° C for 1 hour and grinding with an energy intensity of 8.5 W / g in a vibrating mill to fineness grinding fractions of more than 100 microns 10%.

Then 130 kg of powder are loaded into the mixer and treated with a mixture consisting of 60 liters of a 7% concentration of nitric acid solution, 1.66 kg of ammonium paramolybdate and 2.6 kg of nickel nitrate. Further processing is carried out under the conditions of example 1. Calcination is carried out in an oven at a temperature of 450 ° C for 2 hours.

Ready catalyst chem. composition, wt.%:

NiO 4.6

MoO ₃ 13.0

C 0.04

Al ₂ O _{3 the} rest

The coefficient of mechanical strength is 2.15 kg / mm.

Example 7 (comparative). 150 kg of spent lost its activity of industrial Al-Co-Mo catalyst of chemical composition according to example 1 without preliminary heat treatment is subjected to grinding and further processing under the conditions of example 1.

Ready catalyst chem. composition, wt.%:

CoO 4.3

MoO ₃ 12.3

C 0.04

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.9 kg / mm.

Example 8 (comparative). 150 kg of spent, lost its activity industrial Al-Ni-Mo chemical composition catalyst of Example 5 without preliminary heat treatment is subjected to grinding and further processing under the conditions of Example 1. Ready-made chemical catalyst. composition, wt.%:

NiO 4.6

MoO ₃ 13.0

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.55 kg / mm.

Example 9 (comparative). 150 kg of spent, lost its activity industrial Al-Co-Mo catalyst chemical composition of Example 1 is subjected to grinding with an energy intensity of 2.9 W / g in a ball mill to a grinding fineness of less than 150 μm and further processing under the conditions of example 1.

Ready catalyst chem. composition, wt.%:

CoO 4.3

MoO ₃ 12.3

C 0.04

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.05 kg / mm.

Example 10 (comparative). 130 kg of spent industrial Al-Ni-Mo catalyst of the following chemical composition, wt.%:

NiO 4.1

MoO ₃ 12.6

Al ₂ O _{3 the} rest

Grind with an energy intensity of 2.9 W / g in a ball mill to a grinding fineness of less than 150 microns and further processing in the conditions of example 5. Ready catalyst chem. composition, wt.%:

NiO 4.8

MoO ₃ 14.5

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.8 kg / mm.

Example 11 (prototype). 130 kg of spent, lost its activity industrial Al-Co-Mo catalyst of the following chemical. composition, wt.%:

CoO 3.8

MoO ₃ 13.0

Al ₂ O _{3 the} rest

grind into powder to a fineness of grinding less than 150 microns. Then 100 kg of the obtained powder is loaded into the mixer and 4.3 kg of cobalt nitrate salt is added, stirred for 15 minutes and treated with 90 l of a 20% concentration of nitric acid, the mixture is stirred for 15 minutes and 1.88 kg of ammonium paramolybdate salt is added, mixed at 85 -98 ° C 30 min. The resulting mass is formed into granules, which are dried for 12 hours, dried for 2 hours at 120 ° C and calcined for 6 hours at 500 ° C. Ready catalyst chem. composition, wt.%:

CoO 4.8

MoO ₃ 14.5

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 2.25 kg / mm.

Example 12 (prototype). 130 kg of spent, lost its activity industrial Al-Ni-Mo catalyst chem. composition, wt.%:

NiO 4.1

MoO ₃ 12.6

Al ₂ O _{3 the} rest

ground into a powder to a fineness of grinding fractions of less than 150 microns. Then 100 kg of the obtained powder is loaded into the mixer, 14.6 kg of nickel nitrate salt are added, stirred for 15 minutes and treated with 90 l of 20% concentration of nitric acid, stirred for 20 minutes, 9.0 kg of ammonium paramolybdate are added, and stirred under heating to 90 -100 ° C for 30 minutes, formed, dried for 12 hours at 120 ° C, calcined for 6 hours at 500 ° C. The regenerated catalyst has a chemical composition, wt.%:

NiO 7.2

MoO ₃ 18.5

Al ₂ O _{3 the} rest

The mechanical strength coefficient is 1.85 kg / mm.

The activity of the catalysts was determined by the following method.

In accordance with TU 113-03-00209510-86-2001 for the alumina-cobalt-molybdenum catalyst and TU 113-03-00209510-96-2003 for the alumina-nickel-molybdenum catalyst, the procedure consists in the operation entering the operating mode (360 ° С), preliminary sulfurization of the catalyst during 2 hours (to stabilize the hydrogenating ability), lowering the temperature to 270 ° C with determining the degree of hydrogenation. Test conditions: space velocity of 10,000 h ^-1 , the concentration of diethyl sulfide in terms of sulfur of 16,000 mg / m ³ .

Comparative test results of the catalysts regenerated by the proposed method, the prototype and fresh industrial catalysts of chemical composition, wt.%: CoO (NiO) - 3.8, MoO ₃ - 11.6, Al ₂ O ₃ - the rest during hydrotreatment are given in table.

The catalyst according to example No. Mechanical strength, kg / mm granule diameter Activity by method,% one 1.95 94 2 2.2 98 3 2,35 95 four 2,3 95 5 2,3 98 6 2.15 95 7 (comparative) 1.9 85 8 (comparative) 1.55 94 9 (comparative) 1.05 80 10 (comparative) 1.8 82 11 (prototype) 2.25 94 12 (prototype) 1.85 94 Fresh Industrial Al-Co-Mo 1.4 87 Fresh Industrial Al-Ni-Mo 1.4 87

The data in the table show that preliminary heat treatment in the air atmosphere of spent and lost their activity catalysts based on cobalt, nickel, molybdenum and aluminum oxides and their mechanical activation with an energy intensity of at least 6.6 W / g in a vibration mill made it possible to obtain catalysts with almost equal activity, and in some cases and higher in hydrotreating processes with fresh industrial catalysts.

The use of mechanical activation with an energy intensity of at least 6.6 W / g in a vibrating mill made it possible to obtain a mechanically strong catalyst, the strength coefficient of all samples is at the level of 1.95-2.35 kg / mm, which exceeds the strength coefficient of industrial catalysts, compared with the mechanical prototype the strength of the obtained samples in the above examples is higher or almost at the level.

The use of the proposed method for the regeneration of spent catalysts provides an increase in productivity by eliminating the drying step in comparison with the known method and simplifies the regeneration process.

Claims (1)

A method of regenerating a spent catalyst for hydrotreating petroleum feedstocks based on nickel or cobalt oxides, molybdenum and aluminum oxides, comprising grinding the catalyst into a powder, introducing nitric acid, adding active components — salts of cobalt nitrate or nickel and ammonium paramolybdate, molding, drying, calcining, characterized the fact that the spent catalyst before milling is subjected to heat treatment in an atmosphere of air at a temperature of 550-600 ° C for 1-1.5 hours, then the granules are subjected to mechanical activation with energy with a tension of at least 6.6 W / g in a vibrating mill to a fineness of grinding fractions of more than 100 μm 10-20%, a mixture of 3.5-7% concentration of a solution of nitric acid and salts of cobalt nitrate and nickel and paramolybdate is introduced into the milled catalyst before stirring ammonium