CN1219031C - Beta-zeolite containing anti-nitrogen hydrocracking catalyst - Google Patents

Abstract

The present invention relates to a nitrogen resisting type hydrocracking catalyst containing beta-zeolite. The catalyst has high activity and high medium oil selectivity by matching selected beta-zeolite having suitable properties with acidic amorphous silicon-aluminum having specific properties, and a raw material having a high nitrogen content can be directly treated under the condition of no prerefining section. The catalyst of the present invention can be used for a single-section and single-catalyst hydrocracking technology or a firstly-cracking and secondly-refining hydrocracking technology for producing clean fuel to the maximum, or the catalyst can be matched with other types of hydrocracking catalysts to produce the clean fuel to the maximum.

Description

A kind of anti-nitrogen type hydrocracking catalyst that contains the β zeolite

Technical field

The present invention relates to a kind of hydrocracking catalyst of the β of containing zeolite, particularly relate to a kind of anti-nitrogen type hydrocracking catalyst of the β of containing zeolite.

Background technology

Hydrocracking process mainly can be divided into one-stage process and two-stage method, and operating method mainly can be divided into recycle to extinction and once pass through.Nobel metal hydrogen cracking catalyst is owing to the sulphur in the stock oil, nitrogen sensitivity, generally be used for two-stage method.Non-noble metal hydrocracking catalyst is widely used in the one-stage process technology single hop technology in other words, according to the characteristics at acidity of catalyst cracking center or the difference of anti-nitrogen poisoning performance, can be divided into one-stage serial or single hop list agent technology again.

Hydrocracking catalyst is a kind of dual-function catalyst, promptly has hydrogenating function and has the cracking function again, produces clean fuel so be particularly suitable for handling heavy hydrocarbon feedstocks inferior.On technology, amorphous type hydrocracking catalyst acidic cleavage central characteristics can directly be handled high nitrogen charging, is used for single hop list agent technology more, but the temperature of reaction height because the cracking ability is relatively poor, generally can not adopt the extinction recycle operation mode.The zeolite hydrocracking catalyst has satisfactory stability, life-span and activity, and the zeolite hydrocracking catalyst generally need have a hydrofining section to carry out denitrogenation, and Here it is, and one-stage serial technology is better, and it strengthens the flexibility of operation of hydrocracking process.

On technology, owing to amorphous type hydrocracking catalyst acidic cleavage central characteristics, can adapt to high nitrogen charging, thereby generally be used for single hop list agent technology more, and the middle distillates oil selectivity height of amorphous type hydrocracking catalyst, shortcoming is the temperature of reaction height.The application of zeolite in hydrocracking catalyst changed the shortcoming that amorphous type hydrocracking catalyst activity was low in the past, running period is short, make the stability of catalyzer and life-span better and the flexibility of operation of catalyzer is strengthened, but the hydrocracking catalyst that contains zeolite component, be easy to the nitrogen poisoning and deactivation, so generally need have a hydrofining section to carry out denitrogenation, this just becomes one-stage serial technology.In addition, the zeolite type hydrocracking catalyst of prior art generally speaking, its middle distillates oil selectivity can not surpass the amorphous type hydrocracking catalyst.The characteristics of β zeolite are its selectivity ratios Y zeolite height to the paraffinic hydrocarbons reaction, can obtain the split product of low condensation point.Particularly its three-dimensional straight hole road structure makes the relative cage structure of its reactant make the cracking intermediate have the less residence time and has reduced excessive fragmentation, thereby middle distillates oil selectivity is higher, if improving the acidity feature, will improve middle distillates oil selectivity greatly.

US4820402 discloses a kind of hydrocracking catalyst, mentions the β zeolite, and this patent thinks, in order to improve middle distillates oil selectivity and to reduce the hydrogen consumption, and the silica molecular ratio at least 50: 1 of catalyzer mesolite component, general 100: 1, even 200: 1.When the control transformation efficiency was 60v%, the catalyzer middle distillates oil selectivity was no more than 70v%.CN1210881A discloses that a kind of β of containing boils and the hydrocracking catalyst of amorphous silicon aluminium, β zeolite 5～40w%, amorphous aluminum silicide 10～50w%, and component such as reactive metal, because the zeolite content of this catalyzer is higher relatively and amorphous aluminum silicide content is relatively low, therefore anti-nitrogen is not strong, can only be used for the hydrocracking process with pre-refining.

Summary of the invention

At the deficiencies in the prior art, the invention provides a kind of active high, middle distillates oil selectivity is high, be applicable to and contain β zeolite hydrocracking catalyst in the no pre-refining section hydrocracking process.

The anti-nitrogen type hydrocracking catalyst that contains the β zeolite that the present invention relates to comprises by weight: (a) the low acidity beta zeolite 1%～10% of modification; (b) acid amorphous aluminum silicide＞50% is to 80%; (c) the aperture aluminum oxide 0%～30%; (d) the group vib metal oxide 10%～40%; (e) the VIII metal oxide 1%～10%.Catalyst specific surface is 150-300m ²/ g is preferably 200-250m ²/ g, pore volume is 0.25-0.45ml/g, is preferably 0.3-0.4ml/g.

The infrared acidity of β zeolite wherein generally is not more than 0.50mmol/g, best 0.05-0.40mmol/g, SiO ₂/ Al ₂O ₃Mol ratio is 20～150, and the secondary pore pore volume of 2～10nm accounts for 3060% of total pore volume, specific surface 500-750m ²/ g, Na ₂O weight content＜0.2%.

Wherein acid amorphous aluminum silicide has following character: SiO ₂Content is 20～60%, specific surface 350-600m ²/ g, pore volume 0.9～1.5ml/g, infrared acidity 0.30-0.60mmol/g.

Pore volume 0.4～the 0.8ml/g of wherein little porous aluminum oxide, specific surface 150～300m ²/ g.

Wherein the group vib metal oxide mainly comprises the oxide compound of tungsten or molybdenum, and the VIII metal oxide mainly comprises the oxide compound of cobalt or nickel.

Hydrocracking catalyst of the present invention contains two kinds of character and the specific acid material of consumption is the cracking component, has guaranteed the lytic activity of catalyzer on the one hand, has improved selectivity of catalyst simultaneously.The more important thing is, the β zeolite of selecting has lower acidity, and the content that selection suits cooperates with specific amorphous aluminum silicide, make it on catalyzer, have moderate acid site density, the catalyzer coking inactivation of avoiding the multidigit condensation reaction of intensive strong acid center to cause, with suitable hydrogenation active centre synergy, therefore have stronger anti-nitrogen performance simultaneously, can directly contact and carry out hydrocracking reaction with unpurified raw material.

Embodiment

Catalyzer of the present invention can adopt conventional method preparation, as adopting coprecipitation method, blending method or pickling process etc.Usually adopt pickling process, as amorphous aluminum silicide and zeolite component are mixed, add aperture alumina adhesive through the peroxy-nitric acid peptization mix pinch, extruded moulding obtains carrier, obtain by flooding hydrogenation active metals again.

The acid amorphous aluminum silicide that catalyzer of the present invention relates to can require to select in existing amorphous silicon aluminum according to character.The β zeolite that relates to also can require to select in existing β zeolitic material according to character, but the β zeolite that preferably adopts following process to handle:

(1) the β zeolite slurry of crystallization after fully directly carries out ammonium salt exchange, β zeolite SiO ₂/ Al ₂O ₃Be generally 25～30, Na ₂O content is 3.0w%～4.0w%, and the concentration of ammonium salt in slurries is 0.5～5.0mol/l, and several is carried out in the ammonium exchange, makes Na in the molecular sieve of exchange back ₂The O weight content is not more than 0.5%;

(2) the β zeolite after the ammonium salt exchange filter, wash, drying and roasting, wherein maturing temperature is controlled at 450 ℃～650 ℃, the time is 5.0～15.0 hours;

(3) the β zeolite that takes off behind the ammonium of roasting carries out acid treatment, filters, and wherein acid treatment condition is for being that the mineral acid of 0.1～5.0mol/l is carrying out acid treatment with concentration under abundant agitation condition, 20 ℃～100 ℃ of treatment temps, and the treatment time is 0.5～5.0 hour;

(4) the intact β zeolite of acid treatment carries out the pressurized thermal water processing, and the hydrothermal treatment consists condition is at 550 ℃～730 ℃, and system pressure is 0.05～1.0MPa, handles preferably 1～2 hour 0.5～5.0 hour.

Beta-molecular sieve by above method modification, be characterized in that acidity is lower, the acid site is evenly distributed, the degree of crystallinity height, have more secondary pore and a spot of non-framework aluminum, the catalyzer coking inactivation of avoiding the multidigit condensation reaction of intensive strong acid center to cause simultaneously and suitable hydrogenation active centre synergy, therefore has stronger anti-nitrogen performance.

Catalyzer of the present invention can be used for the hydrocracking process of single hop list agent, or purified hydrocracking process after the first cracking, or is used with other hydrocracking catalyst, is used for maximum and produces clean fuel.Further specify the solution of the present invention and effect below by embodiment.

Embodiment 1

Take by weighing a kind of macroreticular acidic amorphous aluminum silicide (specific surface 520m ²/ g, SiO ₂35m%, infrared acidity 0.40mmol/g) 90.5g and a kind of β zeolite 5.8g, add behind the mixing 120g (adding rare nitric acid peptization preparation) tackiness agent by the little porous aluminum oxide of 14.7g pore volume 0.42ml/g roll agglomerating after, after putting into the banded extruder extruded moulding, 110 ℃ of dryings 10 hours, 500 ℃ of activation made carrier in 4 hours, be total to the steeping fluid dipping with Mo-Ni again, then 110 ℃ of dryings 12 hours, and 500 ℃ of activation obtained catalyzer after 3 hours.Catalyzer finally consists of: amorphous aluminum silicide 65m%, β zeolite 5m%, aluminum oxide 10m%, nickel oxide 4.5m%, Tungsten oxide 99.999 15.5m%.Specific surface area of catalyst is 265m ²/ g, pore volume are 0.39ml/g.

Wherein the character of β zeolite is as follows: zeolite SiO ₂/ Al ₂O ₃Mol ratio 40, specific surface 570m ²/ g, infrared acidity 0.28mmol/g, the secondary pore pore volume of 2～10nm accounts for 41% of total pore volume.Concrete modifying process is as follows: get industrial synthetic SiO ₂/ Al ₂O ₃25.67, Na ₂The Na β zeolite slurry 2000ml of O 3.75m%, contain solid phase 400g (in butt), with water purification solid-to-liquid ratio is diluted to 1: 10, be mixed with the 2.0M ammonium nitrate solution, stir, be warming up to 90 ℃, constant temperature stirred 2 hours, was cooled to 50 ℃ of filtrations then, wet cake carries out the exchange second time again, and condition is with for the first time.Through the β zeolite of twice ammonium salt exchange, wash to pH and reach 5～6, put into loft drier then, 110～120 ℃ of dryings 6 hours.Dried β zeolite is at 540 ℃, constant temperature 10 hours.High-temperature roasting is taken off the β zeolite of ammonium through pulverizing weighing 400g, adds 0.4M HCl 4000ml, stirs and is warming up to 90 ℃, and constant temperature stirred 2 hours, the cold filtration washing.Through acid-treated β zeolite filtration washing, then in 110 ℃ of dryings 6 hours (butt＞80%).Above-mentioned exsiccant sample is carried out hydrothermal treatment consists, and temperature is 580 ℃, control pressure 450KPa, and the treatment time is 2 hours.

Example example 2

According to embodiment 1 method, adjust each amounts of components, final catalyzer consists of amorphous aluminum silicide 72wt%, β zeolite 3wt%, aluminum oxide 5wt%, nickel oxide 5.5wt%, Tungsten oxide 99.999 14.5wt%.Other is with embodiment 1.

Embodiment 3

Take by weighing a kind of macroreticular acidic amorphous aluminum silicide (specific surface 470m ²/ g, SiO ₂30m%, infrared acidity 0.38mmol/g) 77.5g and a kind of β zeolite 10.2g, add behind the mixing 120g (adding rare nitric acid peptization preparation) tackiness agent by the little porous aluminum oxide of 21.7g pore volume 0.42ml/g roll agglomerating after, after putting into the banded extruder extruded moulding, 110 ℃ of dryings 10 hours, 500 ℃ of activation made carrier in 4 hours, be total to the steeping fluid dipping with Mo-Ni again, then 110 ℃ of dryings 12 hours, and 500 ℃ of activation obtained catalyzer after 3 hours.Catalyzer finally consists of: amorphous aluminum silicide 5 1m%, β zeolite 9m%, aluminum oxide 15m%, nickel oxide 6m%, Tungsten oxide 99.999 19m%.Specific surface area of catalyst is 244m ²/ g, pore volume are 0.36ml/g.

Wherein the character of β zeolite is as follows: zeolite SiO ₂/ Al ₂O ₃Mol ratio 40, specific surface 570m ²/ g, infrared acidity 0.28mmol/g, the secondary pore pore volume of 2～10nm accounts for 41% of total pore volume.Concrete modifying process is as follows: get industrial synthetic SiO ₂/ Al ₂O ₃25.67, Na ₂The Na β stone slurries 2000ml of O 3.75m%, contain solid phase 400g (in butt), with water purification solid-to-liquid ratio is diluted to 1: 10, be mixed with the 2.0M ammonium nitrate solution, stir, be warming up to 90 ℃, constant temperature stirred 2 hours, was cooled to 50 ℃ of filtrations then, wet cake carries out the exchange second time again, and condition is with for the first time.Through the β zeolite of twice ammonium salt exchange, wash to pH and reach 5～6, put into loft drier then, 110～120 ℃ of dryings 6 hours.Dried β zeolite is at 540 ℃, constant temperature 10 hours.High-temperature roasting is taken off the β zeolite of ammonium through pulverizing weighing 400g, adds 0.4M HCl 4000ml, stirs and is warming up to 90 ℃, and constant temperature stirred 2 hours, the cold filtration washing.Through acid-treated β zeolite filtration washing, then in 110 ℃ of dryings 6 hours (butt＞80%).Above-mentioned exsiccant sample is carried out hydrothermal treatment consists, and temperature is 650 ℃, control pressure 450KPa, and the treatment time is 2 hours.

Embodiment 4 evaluating catalysts

This process program is handled a kind of heavy distillate: the wax tailings CGO of 90% heavy vacuum distillate VGO blending 10%, this petroleum hydrocarbon material main character is: proportion 0.9045cm ³/ g, 350 ℃-565 ℃ of boiling ranges, carbon residue 0.40m%, sulphur 2.06m%, nitrogen 2226 μ g/g.

This process program operational condition: reaction pressure 15MPa, hydrogen-oil ratio 1200, volume space velocity 1hr ^-1, adopt＞350 ℃ of part cyclical operation modes, control per pass conversion 70m%, stock oil directly contacts with hydrocracking catalyst with hydrogen heating back, need not make with extra care.It is to obtain divided by the liquid yield that has transformed (100 deduct tail oil) by intermediate oil (rocket engine fuel and/or diesel oil distillate) yield that middle distillates oil selectivity calculates.

	Embodiment 1	Embodiment 2	Embodiment 3
				Deactivation rate, ℃/day	0.05	0.04	0.05
Initial reaction temperature, ℃	406	407	402
				Middle distillates oil selectivity, %	83.3	83.1	82.8

Claims (6)

1, a kind of anti-nitrogen type hydrocracking catalyst that contains the β zeolite is characterized in that comprising in its composition of final catalyst weight: (a) the low acidity beta zeolite 1%～10% of modification; (b) acid amorphous aluminum silicide＞50% is to 80%; (c) the aperture aluminum oxide 0%～30%; (d) the group vib metal oxide 10%～40%; (e) the VIII metal oxide 1%～10%; Wherein said group vib metal oxide comprises the oxide compound of tungsten or molybdenum, and the VIII metal oxide comprises the oxide compound of cobalt or nickel.

2,, it is characterized in that catalyst specific surface is 150-300m according to the described catalyzer of claim 1 ²/ g, pore volume are 0.25-0.45ml/g.

3,, it is characterized in that the infrared acidity of described β zeolite is 0.05-0.40mmol/g, SiO according to the described catalyzer of claim 1 ₂/ Al ₂O ₃Mol ratio is 20～150, and the secondary pore pore volume of 2～10nm accounts for 30～60% of total pore volume, specific surface 500-750m ²/ g, Na ₂O weight content＜0.2%.

4,, it is characterized in that described acid amorphous aluminum silicide has following character: SiO according to the described catalyzer of claim 1 ₂Content is 20～60%, specific surface 350-600m ²/ g, pore volume 0.9～1.5ml/g, infrared acidity 0.30-0.60mmol/g.

5,, it is characterized in that the pore volume 0.4～0.8ml/g of described little porous aluminum oxide, specific surface 150～300m according to the described catalyzer of claim 1 ²/ g.

6,, it is characterized in that described β zeolite treatment method is as follows according to the described catalyzer of claim 1:

(1) the β zeolite slurry of crystallization after fully directly carries out ammonium salt exchange, β zeolite SiO ₂/ Al ₂O ₃Be 25～30, Na ₂O content is 3.0w%～4.0w%, and the concentration of ammonium salt in slurries is 0.5～5.0mol/l, and several is carried out in the ammonium exchange, makes Na in the molecular sieve of exchange back ₂The O weight content is not more than 0.5%;

(2) the β zeolite after the ammonium salt exchange filter, wash, drying and roasting, wherein maturing temperature is controlled at 450 ℃～650 ℃, the time is 5.0～15.0 hours;

(3) the β zeolite that takes off behind the ammonium of roasting carries out acid treatment, filters, and wherein acid treatment condition is for being that the mineral acid of 0.1～5.0mol/l is carrying out acid treatment with concentration under abundant agitation condition, 20 ℃～100 ℃ of treatment temps, and the treatment time is 0.5～5.0 hour;

(4) the intact β zeolite of acid treatment carries out the pressurized thermal water processing, and the hydrothermal treatment consists condition is at 550 ℃～730 ℃, and system pressure is 0.05～1.0MPa, handles 0.5～5.0 hour.