CN2477270Y

CN2477270Y - Symmetric three-petal type catalyst

Info

Publication number: CN2477270Y
Application number: CN01211252.6U
Authority: CN
Inventors: 向绍基; 李亚昆
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2001-01-05
Filing date: 2001-01-05
Publication date: 2002-02-20
Anticipated expiration: 2011-01-05

Abstract

Three petal catalyzer or catalyzer carrier with symmetrical transect is characterized in that the diamater(D) of the outer circle is equal to twice the diameter(d) of the inner circle, the lateral area(DNL) of the catalyzer is equal to the lateral area of the column with the diameter of D, and the maximum proliferation long range distance from the outward surface to the center is the same as the diameter of the column with the diameter of d, namely d/2. The catalyzer carrier has the asvantages of large surface area, short proliferation long range, high voidage and high intensity, suitable for the catalyzer carrier of quality distillate, residual oil and other macro molecule catalytic reaction in particular.

Description

Symmetry three petal-shaped catalyst

The utility model relates to the shape, particularly three petal-shaped catalyst and carriers thereof of a kind of catalyst in chemical industry, the petroleum industry and carrier thereof.

Many processes all be unable to do without catalyst in chemical industry, and heterogeneous catalyst plays a significant role in chemical industry, particularly in fixed bed reactors, heterogeneous catalyst has reactant, the segregative advantage of product, but, also often there are some shortcomings in heterogeneous catalyst, and for example: to many heterogeneous catalysts, DIFFUSION CONTROLLED often becomes a key step of restriction catalytic reaction.In order to reduce the influence of spreading factor to heterogeneous catalytic reaction, people have taked various means, such as, increase the time of staying of reactant, improve reaction temperature, improve the pressure of reaction system, particularly at fixed bed catalyst, people take to reduce the size of the macroscopic particles degree of heterogeneous catalyst, reach to reduce the influence of reaction external diffusion factor to catalytic reaction.Such as: the cylinder bar shaped catalyst is used widely at petrochemical industry, but bulky molecular catalysis such as heavy distillate, residual oil are reacted, spreading factor becomes the decision link of restriction catalytic reaction speed, people are in order to reduce the influence of external diffusion to catalytic reaction, take to reduce the diameter of cylinder bar shaped, but the refinement gradually of the cylindric carrier of bar shaped can bring following negative effect:

1. along with the refinement gradually of the cylindric carrier of bar shaped, the intensity of catalyst or carrier can be gradually

Descend;

2. the beds voidage reduces, and tends to cause in the operation process whole fixed bed anti-

Answer the bed pressure drop of device to increase, cause shorten the service cycle of catalyst.

At shortcoming that the simple refinement of cylindrical catalyst is brought and improper part, people have developed various irregular shape catalysts and carrier, one of typical representative is exactly extensively to adopt Raschig ring in the chemical industry, Raschig ring can significantly increase bed voidage, reduce the effect that bed layer pressure is fallen, but it also has the shortcoming of self, such as: difficult forming, difficulty cut off bar, particularly diameter is not more than the Raschig ring industrial more difficult moulding at present of 2mm, and diameter hour, and easily broken, intensity is also relatively poor.

At above-mentioned deficiency, people have developed various irregular shape catalysts again, such as: in patent US4394303, be mentioned to a kind of trilobal cross (three petals) catalyst design, as shown in Figure 3, compare with cylindrical catalyst and carrier, its progressive part is arranged, as: the diameter that has reduced catalyst and carrier to a certain extent, its mechanical strength is enhanced, and voidage increases to some extent.However, but from design point of view, this patent mentioned to the trilobal cross catalyst shape and the size of each blade are not done specific requirement, easy so prepared catalyst or the support shapes disunity of making, mechanical strength and voidage can not get effective assurance, it is not best trilobal cross Catalyst Design scheme, and raising haves much room for improvement.

The utility model purpose is at present trifolium-shaped (three is petal-shaped) catalyst and carrier design scheme deficiency structurally, improves and perfect, proposes a kind of three petal-shaped catalyst and carriers of height symmetry.

Knot and accompanying drawing are described in detail the utility model below:

Fig. 1: the sectional view of three petal-shaped carriers, D are the external diameter of a circle in cross section, and d is a cross section inscribe diameter of a circle; R is the maximum diffusion length of carrier outer surface to the center;

Fig. 2: the side view of three petal-shaped carriers, wherein L is the length of three petal-shaped catalyst;

The utility model proposes a kind of three petal-shaped catalyst and carriers of height symmetry, as illustrated in fig. 1 and 2, have following feature:

Its cross section (cross section) is the three petal-shaped of highly symmetry; Three petals in carrier cross section are 120 degree angles and distribute; The circumscribed circle diameter D in cross section equals 2 times of inscribed circle diameter d; The lateral area of catalyst and carrier is π DL, and wherein L is the length of three petal-shaped catalyst, perhaps is described as: the girth in the cross section of catalyst carrier is π D.

It is suitable that the maximum diffusion long-range of reactant molecule from the outer surface of catalyst and carrier to the center and diameter are that the maximum of the cylinder bar shaped carrier of d spreads long-range; Perhaps be described as: the maximum diffusion long-range of reactant molecule from catalyst and carrier outer surface to the center is r, sees Fig. 1, wherein r=d/2.

The scope of the outer section circular diameter D in the cross section of symmetry three petal-shaped catalyst and carrier is 1～100mm; The scope of the inscribed circle diameter d in cross section is 0.5～50mm.

The symmetry three petal-shaped catalyst that the utility model provides and the embodiment of carrier are easy: as long as the aperture in the orifice plate is designed to required shape (as Fig. 1), then that materials allocating is good, extrusion modling can obtain three symmetrical petal-shaped catalyst and carriers.

The symmetry three petal-shaped carriers that the utility model provides are fit to the heterogeneous catalyst in the preparation fixed bed reactors, are particularly suitable for preparing the catalyst of external diameter less than 2mm.Such as: in petrochemical industry, as macromolecular hydrogenation catalysts such as heavy distillate, pertroleum wax, residual oil, the particle diameter that often needs catalyst is less than 2mm, and requires that catalyst strength is good, reaction bed has certain voidage.At above problem, the utility model is by having adopted a kind of optimal design scheme, make every index of catalyst or carrier all reach the best, make prepared catalyst carrier be suitable for doing catalyst and carrier in heavy distillate, residual oil and the bulky molecular catalysis reaction.Simultaneously, the filler that also is suitable as in chemical industry and the reactor is used.

Symmetry three petal-shaped catalyst and carrier that the utility model provides have following advantage and effect:

Catalyst or catalyst carrier height symmetry easily realize the close filling mutually of catalyst, and the cylindrical catalyst that the strength ratio diameter of catalyst is identical is all good, and the external surface area of catalyst is bigger, the voidage height.

Embodiment and comparative example

Design is as the catalyst carrier of Fig. 3, Fig. 4, Fig. 5, resemblance shown in Figure 6, wherein:

Fig. 3 is the sectional view according to the trilobal cross catalyst carrier (A) of patent US4394303 design, D=2.0mm, d=1.2mm;

Fig. 4 is the sectional view according to the trilobal cross catalyst carrier (B) of patent US4394303 design, D=2.0mm, d=0.9mm;

Fig. 5 is the sectional view of cylindrical catalyst carrier (C), D=2.0mm;

Fig. 6 is the sectional view of the designed symmetry of the utility model three petal-shaped carriers (D), D=2.0mm, d=1.0mm.

Taking by weighing aluminum hydroxide solid elastomer powder (boehmite) adds sesbania powder, carbon black, Ludox, water, peptizing agent and aluminium hydroxide successively and mixes, extrusion modling on banded extruder, take to change the form of extrusion orifice plate, obtain catalyst carrier A, B, C and D respectively, after drying, 550 ℃ of following roastings 4 hours, measure the bulk density (heap ratio) of catalyst carrier, the results are shown in Table 1 for side pressure mechanical strength and voidage.

Table 1: the character of catalyst carrier

Bulk density mechanical strength voidage

Carrier

G/ml N/mm % (v/v) comparative example 1:A 0.62 18 35 comparative example 2:B 0.59 11 38 comparative example 3:C 0.65 15 33 embodiment: D 0.59 23 39

From designed orifice plate and experimental data as can be seen, it is little that the designed symmetry three petal-shaped catalyst carriers of the utility model have bulk density, mechanical strength height, the advantage that voidage is big.

The outer circular diameter that cuts is D tripetalous catalyst of symmetry and carrier, the maximum long-range that is diffused into the center from its outer surface is r, r=d/2=D/4 wherein, having only external diameter is that the cylindrical catalyst of D is diffused into half of the maximum long-range in center (D/2) from its outer surface, and its intensity and voidage will be got well than cylindrical catalyst.

By the designed symmetry three petal-shaped carrier D that go out of the utility model, mechanical strength and voidage go with B (seeing Fig. 3 and Fig. 4) according to the carrier A of patent US4394303 design, and the carrier that the designed symmetry of the utility model three petal-shaped catalyst and catalyst are described is the optimum value in the carrier of trilobal cross catalyst and catalyst.

Claims

1. a cross section is three petal-shaped solid particles, it is characterized in that particle cross section three petal-shaped for symmetry highly; Three petals in carrier cross section are 120 degree angles and distribute.

2. according to the described solid particle of claim 1, the circumscribed circle diameter D that it is characterized in that the particle cross section equals 2 times of inscribed circle diameter d;

3. according to the described solid particle of claim 1, it is characterized in that the particle lateral area is D ∏ L, wherein L is the length of three petal-shaped catalyst.

4. according to the described solid particle of claim 2, the scope that it is characterized in that said circumscribed circle diameter D is 1～100mm; The scope of inscribed circle diameter d is 0.5～50mm.

5. according to the described solid particle of claim 1, it is characterized in that this particle can be used as heterogeneous catalyst or carrier.

6. according to the described solid particle of claim 1, it is characterized in that this particle is suitable for doing catalyst or the carrier in heavy distillate, residual oil and the bulky molecular catalysis reaction.