JPS5980489A - Catalytic cracking process using powdery zeolite catalyst - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalytic cracking process using crystalline zeolites with extremely small particle sizes as cracking catalysts.

Crystalline zeolites are widely used in industrial operations as catalysts for gasoline production. In practice, crystalline zeolites are combined with suitable matrices such as inorganic oxides to form beads suitable for use in moving bed equipment, or Foe.
Formed into flowable catalyst particles suitable for use in equipment.

The gas oil feedstock is contacted with the catalyst in the reactor until the catalyst is deactivated by coke deposition.

The catalyst is then passed to a regenerator where the coke is burned off. The regenerated thermal catalyst is then reintroduced into the reactor and contacted again with the feedstock. This cycle repeats continuously.

Such operations have been very successful industrially and have significant economic benefits. However, relatively large amounts of catalyst are required to satisfactorily convert the feedstock with acceptable selectivity to gasoline. Current fluidized bed riser cracking processes use a catalyst to oil weight ratio of S2 or higher. It is inconceivable that such a large amount of catalyst would be thrown away even when the catalyst is contaminated with coke.

This is particularly because the cracking reaction is endothermic and at least part of the heat required to effect cracking must be obtained by the combustion of coke in the regenerator and the subsequent introduction of a thermal catalyst into the reactor. It is.

The cracking of light oil using crystalline zeolite is disclosed in US Patent No. 3. / IIO, No. 1419, No. 3. / l 1
17,2, t/No. 1, and No. 3 of the same. /l O,i
&, No. 7, and used in these patents, the particle size of the catalyst composites is approximately 0.5 mm. 03 to 6°J
! r1 m (0.0 to 0.15 inch) range (for moving bed operations) or 10 to 750 microns (for FOE operations). The matrices used include both catalytically active materials, such as silica-alumina, and catalytically inert materials, such as silica.

The circulation rate of such catalyst complexes is linked to the catalytic cracking function. For example, in a typical FOE operation, the matrix circulation rate and the catalyst circulation rate are essentially coupled to each other, and this rate is dependent on the catalyst activity. The extent to which coke is removed in the regeneration operation is directly responsible for restoring the catalytic activity of the catalyst complex, and this restoration of catalytic activity increases the circulation rate of the catalyst into the Kratzink unit in order to maintain stable operation. Adjust.

US Pat. No. 3,726 discloses the use of powdered crystalline aluminosilicate zeolite alone or in a matrix as a catalyst to help physically remove the catalyst from the product.

Accordingly, the present invention provides a crystalline zeolite catalyst having a particle size of 0.07 to 0.0 μm and an alpha activity of at least 0.0 μm, and a substantially catalytically inert catalyst heated to a particle size of 30 to 0.00 μm. contacting a solid with a hydrocarbon feedstock, then separating and calcining said solid, recycling the resulting calcined hot solid into contact with said hydrocarbon feedstock, and removing zeolite-catalyzed nucleated hydrogen during said contact. The weight ratio of the raw materials is 00l or less, preferably lIo to koθ00.
A cracking method comprising contacting a hydrocarbon feedstock with a crystalline zeolite catalyst, characterized in that ppm. Suitable zeolites are -Wolite) X, Y
, L, ZSM-y, ZsM-//, ZSM-/co and/or beta, suitable solids are sand, clay, dolomite, glass and/or metal, advantageously the surface area is at least / In one embodiment, the hot solid contacts an unheated feedstock containing already dispersed zeolite catalyst, and after contacting the feedstock at least a portion of the zeolite catalyst is separated from the feedstock and calcined. , is recycled and comes into contact with the feedstock. Contact between the catalyst, solids and feedstock is usually carried out at a temperature of aOO to 65[theta]C, residence time -~lO seconds, solids: oil chloride ~/2:l. Zeolite. The particle size of is preferably less than 1 μm.

The powdered zeolite is then discarded or a portion thereof enters the air calciner together with the heat carrier solid and is recovered from the exhaust gas by conventional means such as electrostatic precipitators and/or bag filters and optionally recycled. be done. Thus, a key aspect of the invention is the separation of cracking catalyst function from the circulating solids. The circulation rate of the solids can therefore be varied within the limits of the individual catalytic cracking device, taking full advantage of mechanical and material advantages, independent of the catalytic activity. Therefore, neither the circulating solids themselves nor their recycling rates are determined by the properties of the crystalline zeolite.

The crystalline zeolite need not be totally heat recycled or may be recycled at a rate different from that at which the solids are recycled.

Since very small amounts of catalyst can be used, it is essential that the crystalline zeolite be highly active. As shown in the example, zeolites with alpha activity of da theta do not work well in the method of the invention.

The alpha activity test is described in ``The Journal of Catalysis.''
lysie) Volume J! r here - 3? Page (191!
(G month).

The use of small particle size catalyst allows for intimate contact between the catalyst and the feedstock, thereby significantly reducing the amount of catalyst required. In a preferred embodiment according to the invention, the catalyst:oil pores are approximately S:t in conventional industrial operations.
It can be reduced from 1IO-ppm per oil weight. This is a decrease of 1 or more by /koz,ooo.

Although larger amounts of catalyst may be used, there is no particular benefit in using more catalyst than is necessary to effectively catalytically crack light oil into gasoline.

The thermal solids that are circulated to provide the heat required for the Clarakink reaction are not strictly limited in type, and the rate of circulation of these thermal solids is independent of the cracking catalytic activity of the powdered zeolite catalyst. Therefore, the solids can be combined with relatively inexpensive materials such as sand, dolomite, clay minerals, glass, and metal particles. Suitable solid materials used as circulating heat carriers in this manner are materials that have substantially no cracking catalytic activity, and their function is merely to provide the heat necessary for the catalytic cracking reaction. However, it should be understood that catalytically active materials can also be used, although they are not preferred. Such materials include silica-alumina, silica-zirconia, silica-titania, powdered clay, and the like. Although these materials have catalytic cracking activity, it is not as great as the activity of powdered crystalline aluminosilicate zeolites, so that their heat transfer and catalytic functions are effectively separated. However, they are not separated to the extent that they are heat carrier inert.

In one embodiment of the invention, it is preferred that the circulating solids have a high surface area, especially when using typically troublesome feedstocks, such as heavy oils, residual oils or large amounts of metal-containing feedstocks. Circulating solids with high surface area trap metals and coke.

A preferred surface area is about /Di/g or greater.

Coke particles can be used as circulating solids in other embodiments of the invention. Therefore, the powdered superactive crystalline aluminosilicate zeolite can be dispersed in coke gas oil or vacuum residue and introduced into a fluidized coker.

Crystalline aluminosilicate zeolites useful in the novel process of the present invention are well known in the art and include Zeolite
, Y, beta, L as well as mixtures thereof,
Zeolites with small pores such as erionite, mordenite, ZBM-! r, ZBM-g, ZF3M-// 1
O and ZEIM-/2 can also be used as long as they have a predetermined alpha activity value. A suitable crystalline aluminosilicate zeolite is Zeolite)! and Y, especially their rare earth exchange, acid, or rare earth-acid forms. Mixtures of zeolites can also be used. The process of the present invention may start with one type of zeolite and then replace the zeolite with other zeonites to meet product requirements. Thus, for example, catalysts such as rare earth Y
Starting from the starting point and then quickly adapting to the available feedstock and the market demand for the product, a catalyst that maximizes distillate production such as dealuminated Yl or a dewaxing catalyst such as Z8M-& , or can switch to using mixtures of these catalysts.

In order to carry out the novel process of the present invention, it is necessary that the particle size of the heat carrier solid be substantially larger than the micron size of the powdered crystalline aluminosilicate zeolite. Since it is desirable to separate the heat transfer function from the catalytic function, it is also necessary to be able to separate the thermocycling solids from the powdered crystalline aluminosilicate zeolite.

The larger the particle size of the thermocycling solid is than the particle size of the powdered crystalline aluminosilicate zeolite, the easier the separation will be. As used throughout this specification and claims, therefore, a "thermal cycling solid" is preferably a catalytically inert solid material, the particle size of which is between 30 and 300 microns, more preferably between 30 and 200 microns. shall mean some solid substance. Mixing of the feedstock and catalyst may be carried out before the feedstock is introduced into the reactor. In such a mode of operation, in order to avoid deactivation of the catalyst, , it is preferred to bypass or eliminate the feed preheater.

However, if it becomes necessary to use a preheater, other modes of operation include dispersing the catalyst in a separate cold hydrocarbon stream and injecting the resulting cold hydrocarbon stream directly into the catalytic cracking device, while The remaining portion of the hydrocarbon feedstock, such as gas oil, is passed to the feedstock preheater.

Another advantage of the present invention is that additional functionality can be attached to the circulating solids, for example using antimony compounds to
, a carbon monoxide combustion catalyst, such as a substance with emission control function or trace amounts of platinum or other known oxidizing function, can be incorporated.

The figure is a schematic diagram of the method of the invention. The powdered crystalline aluminosilicate is dispersed in the hydrocarbon feedstock and the resulting mixture is fed to the mixing zone/where it comes into contact with a hot solid, for example sand, which enters the mixing zone l through line 3. The hot solids and relatively cold catalyst-oil mixture are equilibrated in mixing zone I and passed to the reactor, where the hydrocarbon oil is catalytically cracked to a low molecular weight product, such as gas oil.

Generally, the catalyst-oil mixture moves through the reactor at a faster rate than the heat carrier solid. The product from the reactor passes to a separator where gas and liquid products are separated. Although this liquid product contains some micron or submicron crystalline aluminosilicate zeolites, the presence of these materials in the product oil poses no technical problem. The remaining part of the powdered material passes through the pipe S together with the solids and enters the air calciner B, into which air is introduced through the pipe 7. The powdered crystalline aluminosilicate zeolite passes through the piping and enters the filter 9 where it is recovered, disposed of, or partially recycled to the reactor 3 through the piping IO. The hot solids from the air calciner 6 are recycled through line 3 to the mixing section/.

Next, the present invention will be explained based on examples.

Preparation of Feedstock Waxy, high pour point Gippsland crude oil was used for all examples below. Table 1 summarizes the properties of the crude oil. Crude oil has a temperature of 276℃ (11
,20? ) fraction below (λ/l, °C-), and 2/A
It was fractionated into the atmospherically distilled crude oil fraction (which includes the residual oil) above °C (J/A °C+). The atmospherically distilled crude oil fraction was used as feedstock without further purification or separation.

Chapter/Table Specific gravity (API degree) Dal. 9 Sulfur (wt%) θ, /l Carbon residual amount (wt%)
0.23 viscosity [centistokes (cs
),? g℃] 2.09 pour point
/Left, A”C (AO’F) Nickel (ppm)
<θ,/vanadium (ppm)
o, tb nitrogen (ppm)
? Hydrogen (wt%) / Boiling point range
Volume CH Initial boiling point -4I9℃ (l O″F) q.

Data/? 3℃(/2O-3IO@I') 3
41. /93-31I3℃(3tro-t,5ohF
),? 2. tr3113℃+(1,30″F+
) 26.6 General test procedures Fluidized bed reaction of simple atmospherically distilled crude oil or atmospherically distilled crude oil containing dispersed acid type cracking catalyst qoo to koo oppm at a rate of 13 g/min maintained at 370 °C loaded into the vessel. The reactor contains soml (79 g) of γ-alumina particles which become the heat transfer solid. These particles are distributed between helium flow: 1 ornl/'min or A; Oynl/' depending on the activity of the dispersed catalyst and the desired oil residence time.
It is fluidized by flowing %. Mass balances were taken at IO minute intervals. To determine the value of coke for mass balance, the oil was momentarily shut off and the reactor was flushed with helium, and the coke deposited on the heat transfer solid was then combusted in a stream containing oxygen and lIO in nitrogen. Then, the combustion gas is irradiated with CO, aO, and ζ until all the coke is combusted.
IR) detector. At the end of combustion, the reactor was flushed with helium before restarting the crude oil/dispersed catalyst feed pump.

Example/-3 In the following example (one example unless otherwise specified) is an example. Example 1 is a comparative example.
−/, 2θ mesh) fluid particles/9? The basic pre-experimental procedure was first carried out without the addition of dispersed catalyst. After this thermal experiment operation, the raw material was switched to a raw material containing a dispersed catalyst.

170// SiO2/Al2O to make a dispersed catalyst
, ratio (7) Z8M-A; US Patent No. J21,9t
Steam activation was performed to an alpha value of 16θθ according to the method of No. 1I. This zeolite was in powder form and contained particles of 7 microns or less. Zeolite has a concentration of 1 in crude oil
Dispersed at 100pp.

In the second group of experiments, U.S. Pat. lI? 3.379
Alpha value 10 from RKY (rare earth exchange Y) according to the issue
, 200 superactive rare earth exchanged Y was prepared.

This preparation consists of rare earth-exchanged YAr2f with 2.0 moles of NH4
No. 8.791! ;, contact with t'i for 1 hour at 0°C, then the obtained rare earth exchanged Y is heated with saturated steam! 3t
Steamed for 1 hour at
No. 7 Neutralization) Processed items! r3r”c, (1
0θO″F) for 1 hour and ion exchanged with 2 mol of hot NH, No. Then, this product was fired again for 1 hour,
Ion exchange was performed with boiling NH, No. for 1 hour, and washing was performed with boiling water. The washed material was ion-exchanged again with boiling NH, No, (, 1 mol) for 1 hour, and washed with boiling water.
When dried overnight at 130" F., it started to crumble.

Zeolites are in powdered form and consist of particles of -μm or smaller. The concentration of this zeolite in oil is λθ
Dispersed at o o ppm.

Thermal cracking experiments and catalyst addition experiments were carried out using helium as the fluidizing gas at about 70 °C and H/3f oil/min, respectively.
/min. From the results shown in Table 1, highly active ZSM (and superactive REY) are clearly effective catalysts in dispersion cracking systems.

Table 7.23 Conversion rate (wt%) -76℃-(lI2θ-) -1 da, S da0
．． A Rich. 63-tei 3℃-(AtOIF-)
-,77,7t,t,q slIρ product (wt%) 0, -9. Ko /, 2
/ρo, -i, i ko,
/ /, 70s -Oo, 2
/Koro 0 3. IO4-θ, evening g, co
/, 7 C3-ko/6℃ (lI206F) gu, 3 /A
,2 I9,3 :l! ;,/ko16℃-3da3℃(A,to bottom) rll,ko Sl,θ da1.
Wag g, 33 da 3℃+(arO'F+)
lI/J xr,za/! ,0
I9. /Coke - <0. /
0,3 <0.1 Example 4I-6 To reduce thermal decomposition (thermal cracking), the following experiments varied the flow rate of the fluidizing gas from about 20 mt 1 min to about g left θ-
Shorter vapor residence times were performed by increasing the temperature to 1/min. In addition to the pyrolysis experiments (Example G, Comparative Example), a type of catalytic tartaring experiment was carried out under the same conditions except that a type of highly active zeolite catalyst dispersed in oil prepared as previously described was used. . The results shown in Table 3 show that the conversion reaction due to thermal reaction is significantly reduced, and the highly active dispersed catalyst is
℃-(Il, 20″F) indicating a significant conversion of the feedstock to the trolled product.

Table 3 Example 11. t4 conversion rate (wt%) 216℃-(g, 20"F) 6.3
Kok, l Kog. 5 Product (wt%) 0, -1-02 -
0. ．． 3 /, g θ.も03+
C4-θ...? /, 2.7? , ZaC3-ko/
6℃ (lI here”p) I1.3 9
．． ? /,7ρ koθ,ri2/A℃−
3'13℃ (/lSOη5 starvation, t4', A'
3g, -ri/, θ34t3℃+(6,tO'P+)
/l/,s 3a,b 3a,s
, iq, q coke −〇, /
0. ．． 2 00.2 Examples 7-9 (comparative examples) In the last group of experiments, a type of commercially available acid form catalyst was used as a dispersion catalyst, H2SM-, t, and steam-stabilized rare earths treated with Nisteam to give an alpha value of lio. It is an exchanged Y cracking catalyst (α=0.5). These catalysts are more thermally active than the batches used in the previous experiments as indicated by the high yields of methane.
- evaluated in the presence of a batch of alumina. The test results shown in Table 1 along with the pyrolysis experiments show that these commercially available acid form catalysts are not effective when used in dispersed form and at low concentrations. These experimental results demonstrate the importance of using catalysts that inherently have high acid activity.

Table 7 Example (comparative example) 7 g 9 Conversion rate (weight %), 2/A°C - (guko θ12) - here, 3 here, g body, l (: 20) Product (weight %) 0, -1. Dam／／、
λC2-ko,t,2.3/,IO3-,3
,/ ,? 1. ? G, SC4-2, / Ko6.2 3J C! +-core 6℃ (41,201') 11.3
ib,ll/A. 9 lri,ri J
/A℃-3'13℃(Otsu!rθ1") !re,,z
st, t qza, A +7. 313℃+(
6taO〒+) lIt,s here, 5ko5.3
Rich. Zacoke -〇, -〇, 30
．． 3

[Brief explanation of the drawing]

The figure is a schematic diagram of the method of the invention. In the figure, /...Mixing section, Co...Reactor, Ri...Separator, t...Air calciner, 9
・・Swallowing device. Procedural amendment November 7, 1980 Dear Commissioner of the Patent Office 1, Indication of the case 1982 Patent Application No. 17tJ! s No. 2, Title of the invention Catalytic cracking method using powdered zeolite catalyst 3, Relationship to the case of the person making the amendment Patent applicant name (RI1IO) Mobil Oil Corporation 4, Agent (2) Drawings ( 3) Contents of the amendment to the power of attorney (as per the attached application form in 11) (2) Engraving of the drawings (no changes to the contents) (3) As per the attached power of attorney

Claims (1)

Claims: l A crystalline zeolite catalyst with a particle size of o, oi to 3 μm and an alpha activity of at least SOO; and a heated substantially catalytically inert solid with a particle size of 30 to 300 μm. A hydrocarbon raw material is brought into contact with both of the
The solids are then separated and calcined, and the resulting calcined hot solids are recycled and brought into contact with the hydrocarbon raw material at a zeolite catalyst/hydrocarbon raw material weight ratio of 0.
/A cracking method comprising contacting a hydrocarbon feedstock with a crystalline zeolite catalyst, characterized in that: U Crystalline zeolite catalyst/hydrocarbon raw material weight ratio is 0
Claim 1 which is o o o ppm
The method described in section. 3 The crystalline zeolite catalysts are zeolites X, Y, and L. ZSM-! ;, ZBM-//, Z8M-/J and /l
or beta. The method according to any one of claims 1 to 3, wherein the solid is sand, clay, dolomite, glass, or metal. y) The method according to any one of claims 1 to d, wherein the solid has a surface area of at least /Om"7 g. y) The heated solid is an unheated hydrocarbon feedstock in which a zeolite catalyst is already dispersed. The first claim touching
The method according to any one of Items 1 to 3. 2. A method according to any one of claims 1 to 6, wherein at least a portion of the crystalline zeolite catalyst is separated after contact with a hydrocarbon feedstock, calcined and recycled for contact with the feedstock. Method. The contact between the crystalline zeolite catalyst, the solid, and the hydrocarbon feedstock is carried out at a temperature of 300 to 10°C, a residence time of 1 to 10 seconds, and a solid niobyl ratio of 1:1 to 12:1.
The method according to any one of claims 1 to 7, which is carried out in /.