CN1031030A - The preparation of low content of rare earth super-stable Y molecular sieves - Google Patents

Abstract

A kind of be used for cracking hydrocarbon, low content of rare earth, super-stable Y molecular sieves, be to be raw material, through mixed once exchange, the stabilization processes of ammonium ion and rare earth ion, slough that steps such as part framework aluminum atom, heat or hydrothermal treatment consists are prepared into NaY type molecular sieve.Content of rare earth (the RE of this molecular sieve ₂O ₃) be 0.5～6 heavy %, SiO ₂/ Al ₂O ₃Reach 9～50, lattice constant a ₀Be 24.25～24.40 .This molecular sieve is applicable to catalytic cracking, the hydrocracking catalyst of the hydro carbons that comprises mink cell focus.

Description

The preparation of low content of rare earth super-stable Y molecular sieves

The invention relates to a kind of preparation method who is used for the super-stable Y molecular sieves of cracking hydrocarbon, exactly, about a kind of mink cell focus cracking, low preparation method content of rare earth, super steady Y type molecular sieve of being applicable to.

Along with the development of petroleum refining industry to the deep processing direction, cracking technology is employed more and more widely, and Cracking catalyst is faced with how to improve optionally problem under high activity.

Present rare earth-Y (REY) type molecular sieve catalyst of widely using, the general REY type molecular sieves of making through twice rare earth ion exchanged, twice high-temperature roasting that adopt of its active component more.Though this molecular sieve is active high, the higher (RE of content of rare earth wherein ₂O ₃About 18～20 heavy %), and in cracking process because hydrogen transfer reaction is accelerated simultaneously, and caused optionally reducing.For addressing the above problem, U.S. Grace company (USP4,218,307) makes (RE of low content of rare earth ₂O ₃About 0.5～4 heavy %) super-stable Y molecular sieves, but the preparation method of this molecular sieve is complicated, need carry out repeatedly respectively ammonium ion and/or repeatedly rare earth ion exchanged, stabilization processes, repeatedly inorganic acid is taken out steps such as aluminium, back exchange and is made.

The purpose of this invention is to provide a kind of more simpler than prior art, low preparation method content of rare earth, super-stable Y molecular sieves.The present invention also provides with the Preparation of catalysts method of this molecular sieve as active component.

Method provided by the invention is: with the mixed once exchange of Y zeolite through ammonium ion and rare earth ion, stabilized then processing, acid are taken out steps such as aluminium, heat or hydrothermal treatment consists and are made low content of rare earth, super-stable Y molecular sieves, this molecular sieve are scattered in promptly can be made into the said catalyst that is applicable to that mink cell focus transforms of the present invention in the suitable matrix.

According to method provided by the invention, the preparation process of this super-stable Y molecular sieves is as follows:

1. the mixed once of ammonium-rare earth ion exchange: with SiO ₂/ Al ₂O ₃〉=4.2, the NaY type molecular sieve of relative crystallinity 〉=90% is a raw material, is 10～50: 1 ammonium salt with the mol ratio of ammonium ion and rare earth ion and mix RECl ₃The mixed liquor of solution carried out ion-exchange 1～2 hour to NaY type molecular sieve under 80～90 ℃, make the RE in the molecular sieve of exchange back ₂O ₃Content is 0.5～6 heavy %.Used ammonium salt can be hydrochloride, nitrate, sulfate etc.

2. stabilization processes: behind the free acid group of the Y zeolite flush away that contains rare earth after the exchange, roasting is 2～4 hours under 550～850 ℃ of moving airs or self hydro-thermal atmosphere, makes the lattice constant a of molecular sieve _o≤ 24.50 .The filter cake water content should be controlled at 30～70 heavy % during self hydrothermal treatment consists, is advisable with 45～50 heavy %.

3. slough the part framework aluminum: with concentration is 0.01～2N, and the inorganic acid that is preferably 0.1～1N is (as HCl, HNO ₃, H ₂SO ₄Deng), under room temperature～100 ℃ and well-beaten condition, slough part framework aluminum atom in the molecular sieve with 20～100 milliliters rate of addition per hour.The addition of acid reaches 1.0～3.3 with solution PH, best 2.0～3.0 constant being as the criterion.

This dealumination process also usable concentration is that organic acid (as acetate, tartaric acid, the citric acid etc.) solution of 0.5～4N carries out under 50-100 ℃ and well-beaten condition, and the addition of acid reaches 4～4.5 constant being as the criterion with the PH of solution.

4. heat or hydrothermal treatment consists: behind the free acid group of the Y zeolite flush away of part dealuminzation, in 500～600 ℃ of air, handle 4 hours or 650～800 ℃, 100% steam treatment promptly got super-stable Y molecular sieves of the present invention in 4 hours.

With the super-stable Y molecular sieves that makes in required ratio, molecular sieve for example: carrier: binding agent (weight ratio)=10～30: 65～85: 5, being dispersed in the suitable carrier and adding binding agent is that Chinese herbaceous peony is shot a glance at the super-stable Y molecular sieves catalyst that sends the timid rotten posthumous title Dao of the phonetic  of rotten straightforward words  ⑻ torr fish hawk to look appropriate .Used carrier can be: alumina silicate, magnesium silicate, zirconium silicate, kaolin, sepiolite, smectite etc.Binding agent can be: aluminium colloidal sol, Ludox etc.

According to the super-stable Y molecular sieves that the method for the invention makes, the low (RE of its content of rare earth ₂O ₃0.5 lattice constant is 24.25～24.40 , SiO～6 heavy %), ₂/ Al ₂O ₃Can reach 9～50, degree of crystallinity can keep original more than 85%, and the preparation method is simple, and this molecular sieve is applicable to catalytic cracking, the hydrocracking catalyst of the hydro carbons that comprises mink cell focus.

With this super-stable Y molecular sieves is active component, the Cracking catalyst that makes according to the method for the invention, not only having more conventional REY type molecular sieve catalyst is high activity, and can reduce hydrogen transfer reaction effectively, thereby have the selectivity of general super-stable Y molecular sieves catalyst for getting well.When this super-stable Y molecular sieves is used for catalytic cracking catalyst, the gasoline yield height in the gained crackate, coking yield is low, the productive rate height of alkene and isoparaffin in the cracking gas.When this super-stable Y molecular sieves is used for hydrocracking catalyst, then not only can improves the productive rate of the middle distillate oil in the crackate, and can reduce the severity of operation.

Following example will be made further instruction to the present invention.

Example 1～4

Prepare super-stable Y molecular sieves a, b, c, the d of low content of rare earth by molecular sieve preparation method of the present invention.

The preparation of molecular sieve a:

(1) get directing agent method synthetic, degree of crystallinity 92%, SiO ₂/ Al ₂O ₃=5.1, Na ₂NaY type molecular sieve 100 grams (in butt) of O13.5% add 1000 milliliters of deionized waters and fully stirred 30 minutes;

(2) add 35.7 milliliters of RECl in the gained slurries ₃Solution (207 milligrams of RE ₂O ₃/ milliliter, wherein Ce ₂O3 49%, La ₂O ₃25%) and 54.1 the gram NH ₄Cl (Red Star chemical plant, Beijing product, chemical pure, content ≮ 98.5%) continues to stir 30 minutes and be warming up to 80 ℃, under agitation carries out ion-exchange 1 hour;

(3) exchange after molecular sieve after filtration, the washing to there not being Cl ^-, 650 ℃ of roastings 2 hours (its filter cake water content about 46%) in muffle furnace;

(4) molecular sieve after the roasting adds 800 milliliters of deionized water making beating after reducing to room temperature, drips 100 milliliters of 0.25NHCl in 60 ℃ under fully stirring;

(5) molecular sieve filtration behind the part dealuminzation, washing are to there not being Cl ^-, 540 ℃ of roastings promptly got and hang down content of rare earth, super-stable Y molecular sieves a in 4 hours in muffle furnace.

The preparation method of molecular sieve b is identical with a, still:

(3) in roasting condition be 680 ℃ 4 hours;

(4) the HCl addition in is 150 milliliters.

The preparation method of molecular sieve c is identical with a, still:

(1) used deionized water is 800 milliliters in;

(2) used RECl in ₃Solution is 65 milliliters;

(3) in roasting condition be 680 ℃ 2 hours;

(4) used deionized water is 1000 milliliters in, and used HCl is 0.20N, 1200 milliliters.

The preparation method of molecular sieve d is identical with a, still:

(4) dealumination reaction in carries out under 65 ℃, and used HCl is 0.20N, 200 milliliters.

Prepared molecular sieve a, b, c, d are recorded lattice constant a with reference to the described method of ASTM-D3 942-80 respectively on x optical diffraction instrument _o, use formula $\mathrm{Si}{O}_2/{\mathrm{Al}}_2{O}_3=(\frac{1.6665}{a_o-24.191}-1)\×2$ Calculate SiO ₂/ Al ₂O ₃, record RE with x light fluorometric method ₂O ₃Content is used low temperature N ₂Absorption method records specific surface and pore volume, and records the molecular sieve structure fail temperature with Differential scanning calorimetry, and test result sees Table 1,

Table 1

Example	??1	??2	????3	??4	Comparative example 1
						Molecular sieve numbering RE 2O 3Content, heavy % SiO 2/Al 2O 3, mol ratio lattice constant a oThe specific surface, the meters squared per gram pore volume, milliliter/gram differential thermal destroys the peak, ℃	??a ??3.2 ??31.7 ??24.29 ??848 ??0.36 ??1050	??b ??3.1 ??40.2 ??24.27 ??848 ??0.35 ??1055	????c ????5.0 ????23.8 ????24.32 ????870 ????0.37 ????1050	??d ??4.8 ??35.4 ??24.28 ??850 ??0.36 ??1054	??e ??19.5 ??5.4 ??24.64 ??718 ??0.28 ??954

Comparative example 1

Hand over two roasting methods to make REY type molecular sieve e according to conventional two.

(1) gets 100 gram NaY type molecular sieves (specification is with example 1), according to NaY: RECl ₃Solution (specification is with example 1): the ratio of water=1: 0.25: 10 (weight ratio), under agitation in 90 ℃ of exchanges 2 hours;

(2) filter flush away Cl ^-, 120 ℃ of dryings 2 hours, 550 ℃ of roastings 4 hours,

(3) one hand over a roasting back gained molecular sieve, according to molecular sieve: RECl ₃Solution: the ratio of water=1: 0.15: 10 (weight ratio) under agitation exchanges 2 hours once more in 90 ℃;

(4) same step (2) once more roasting promptly get REY type molecular sieve e.

Molecular sieve e is carried out and molecular sieve a, b, every index, performance evaluation that c, d are identical, and the results are shown in Table 1.

Comparative example 2

According to patent USP4,218,307 example 2 described methods are made low content of rare earth, super-stable Y molecular sieves f.

(1) gets 100 gram NaY type molecular sieves (specification is with example 1), weigh % (NH with 10 with 4: 1 liquid-solid ratioes ₄) ₂SO ₄(Beijing Chemical Plant's product, chemical pure, content ≮ 99%) solution is 80 ℃ of exchanges twice under agitation, exchange 1 hour at every turn, between twice exchange after filtration, washing (the flush away SO that dissociates ₄ ⁼);

(2) molecular sieve after the exchange adds 800 milliliters of deionized waters and 40 milliliters of RECl ₃Solution (specification is with example 1) under agitation in 90 ℃ of exchanges 30 minutes, filters, washing (the flush away Cl that dissociates ^-), 120 ℃ of dryings 4 hours, 760 ℃ of roastings are 2 hours in the moving air;

(3) molecular sieve after the rare earth exchanged with 4: 1 liquid-solid ratio with 10 heavy % (NH ₄) ₂SO ₄Solution 80 ℃ of exchanges under agitation 1 hour are filtered, washing (the flush away SO that dissociates ₄ ⁼) 120 ℃ of dryings 2 hours (and this moment the gained molecular sieve Na ₂O content is 0.25 heavy %, RE ₂O ₃Content is 3.9 heavy %);

(4) get the dry back of step (3) exchange molecular sieve 65 grams, use 0.1NHNO ₃Solution is under agitation in 30 ℃ of dealumination reactions twice, each 4 hours, filters, washs (the flush away NO that dissociates then ₃ ^-), 120 ℃ of dryings 2 hours;

(5) molecular sieve behind the dealumination reaction is according to molecular sieve: RECl ₃Solution (100 milligrams of RE ₂O ₃/ milliliter, wherein Ce ₂O ₃49%, La ₂O ₃25%): the ratio of water=1: 1: 10 (weight ratio), under agitation, filter, wash (the flush away Cl that dissociates then in 90 ℃ of exchanges 30 minutes ^-), 120 ℃ of dryings promptly got the molecular sieve finished product in 2 hours.

The Na of prepared molecular sieve f ₂O content is 0.20 heavy %, RE ₂O ₃Content is 5.4 heavy %.

Comparative example 3

Get NaY type molecular sieve (specification is with example 1), weigh % (NH with 10 with 4: 1 liquid-solid ratioes ₄) ₂SO ₄(specification is with comparative example 2) solution 80 ℃ of exchanges under agitation 5 times exchange 60 minutes at every turn, between per twice exchange after filtration, washing (the flush away SO that dissociates ₄ ⁼), after the 5th exchange with molecular sieve 600 ℃ of roastings 4 hours (its filter cake water content about 30%) in muffle furnace.Na in the Y zeolite of the stabilisation of so making ₂O content is 0.32 heavy %, and this molecular sieve note is made molecular sieve g.

Example 5

Preparation method by foregoing molecular sieve catalyst prepares low content of rare earth, super-stable Y molecular sieves catalyst A, B, C, D and contrast molecular sieve catalyst E, F, G.

With molecular sieve a, b, c, d, e, f, g respectively with molecular sieve: (the Suzhou machine selects 2 to kaolin ^#): (Changling Refining Plant of Chinese General Petrochemical Industrial Cooperation's product, Al/ Cl ratio is 1.3 to aluminium colloidal sol, Al ₂O ₃Content is 11.99 heavy %): water=15: 80: 5: the ratio of 200 (weight ratios) mixes, and spray drying forming promptly gets corresponding molecular sieve catalyst A, B, C, D, E, F, G.

Example 6

Molecular sieve catalyst provided by the present invention hands over two roasting REY type molecular sieve catalysts to have better catalytic cracking activity and selectivity than conventional two.

Through molecular sieve catalyst A, B after 4 hours of 800 ℃, 100% steam treatment, C, D, E is that raw material is estimated with the mink cell focus on atmospheric fixed bed reactor respectively.Raw materials used oil be 1: 2: 2 (weight ratio) grand celebration decompression residuum, second line of distillation wax oil, subtract the mixture (its boiling range sees Table 2) of three-way wax oil, reaction temperature is 520 ℃, during weight space velocity 6.5 ^-1, agent/oil 0.5,20～40 order catalyst loading amounts 5 grams, evaluation result sees Table 3.In the table listed conversion ratio be gasoline, diesel oil, cracking gas, coke four portion of product productive rate and, product selectivity is the productive rate percentage (following example with) of this product under the unit conversion rate.

Table 2

Grand celebration subtracts two, three-way wax oil boiling range
	Initial boiling point, ℃ 10% 30% 50% 70% 90% do
???366????????423?????444?????467?????493?????528????544
	Big bed distillation range of residual oil
Initial boiling point, ℃ 10% 15% 20% 25% 27%
	???351????????533???????565???????586???????604??????614

Table 3

Catalyst		????A	???B	????C	????D	????E
							Conversion ratio, heavy %		??63.3	??66.5	??64.3	??66.9	???59.8
Selectivity, %	Gasoline (60～200 ℃) diesel oil (200～330 ℃) cracked gas coke	??47.1 ??33.3 ??17.1 ? ??2.6	??44.7 ??31.6 ??21.1 ? ??2.7	??45.1 ??30.6 ??21.5 ? ??2.9	??45.3 ??31.2 ??20.8 ? ??2.7	???43.3 ???29.1 ???23.9 ? ???3.6
							Generate oily final boiling point, ℃ oily bromine valency of generation, gram bromine/100 grams		??502 ??53.6	??502 ???/	??505 ???/	??503 ??52.8	?＞523 ???40.6

By table 3 data as can be known: though the content of rare earth among the molecular sieve catalyst A provided by the present invention, B, C, D is far below conventional REY type molecular sieve catalyst E, but when the mink cell focus catalytic cracking, the former activity and selectivity all are better than the latter.

Example 7

It is many that molecular sieve cracking catalyst provided by the present invention has in the cracking gas alkene and isoparaffin, the characteristics that coking yield is low.

Molecular sieve catalyst A, F, G are estimated according to example 6 described methods, the results are shown in Table 4.

Table 4

Example 8

Under identical heavy metal pollution condition, the Y zeolite catalyst that molecular sieve catalyst provided by the present invention has than low content of rare earth, super-stable Y molecular sieves catalyst and stabilisation in the prior art is high yield of light oil and lower coking yield.

Molecular sieve catalyst A, F, G are carried out saturated dipping with the kerosin of nickel naphthenate and aphthenic acids vanadium respectively, and carefully oven dry in 500 ℃ of roastings 2 hours, promptly gets the catalyst of nickel and pollution of vanadium more then.Estimate according to example 6 described methods polluting forward and backward catalyst, the results are shown in Table 5.

Table 5

Claims (6)

1. the preparation method of a low content of rare earth super-stable Y molecular sieves is characterized in that its preparation process is:

(1) mixed once of ammonium-rare earth ion exchange: with SiO ₂/ Al ₂O ₃〉=4.2, the NaY type molecular sieve of relative crystallinity 〉=90% is a raw material, is 10～50: 1 ammonium salt with the mol ratio of ammonium ion and rare earth ion and mix RECl ₃The mixed liquor of solution carried out ion-exchange 1～2 hour to NaY type molecular sieve under 80～90 ℃;

(2) stabilization processes: behind the free acid group of the molecular sieve flush away after the exchange, roasting is 2～4 hours under 550～850 ℃ of moving airs or self hydro-thermal atmosphere;

(3) slough the part framework aluminum: be the inorganic acid of 0.01～2N with concentration, under room temperature～100 ℃ and well-beaten condition, slough part framework aluminum atom in the molecular sieve with 20～100 milliliters rate of addition per hour, the addition of acid reaches 1.0～3.3 constant being as the criterion with solution PH;

(4) heat or hydrothermal treatment consists: behind the free acid group of the Y zeolite flush away of part dealuminzation, in 500～600 ℃ of air, handled 4 hours or 650～800 ℃ of 100% steam treatment 4 hours.

2. in accordance with the method for claim 1, it is characterized in that used ammonium salt can be hydrochloride, nitrate, sulfate in the step (1).

3. in accordance with the method for claim 1, it is characterized in that said self hydro-thermal atmosphere is 30～70 heavy % by water content in the step (2), the filter cakes of best 45～50 heavy % provide.

4. in accordance with the method for claim 1, it is characterized in that said inorganic acid in the step (3) is preferably hydrochloric acid, nitric acid or the sulfuric acid of 0.1～1N, the addition of acid preferably reaches 2.0～3.0 constant being as the criterion with solution PH.

5. in accordance with the method for claim 1, its feature plan is deceived street 3) said dealumination process also the acetate, tartaric acid, citric acid of available 0.5～4N under 50～100 ℃ and well-beaten condition, carry out, the addition of acid reaches 4～4.5 constant being as the criterion with solution PH.

6. catalytic cracking of hydrocarbon, the low content of rare earth of hydrocracking catalyst, a super-stable Y molecular sieves that is used to comprise mink cell focus is characterized in that it is by the described method preparation of claim 1.