阅读说明：本技术 重烷基苯反烃化催化剂及其制备方法和应用 (Heavy alkylbenzene anti-alkylation catalyst and preparation method and application thereof ) 是由 解委托 陈锡武 陈鉴 代训达 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种重烷基苯反烃化催化剂,其由如下原料制备而成：25-85wt％的沸石分子筛；15-75wt％的粘结剂组分。其次本申请还公开了采用上述催化剂的制备方法和应用。利用本申请中的催化剂,能够高效地对重烷基苯进行反烃化,重烷基苯转化为轻质烷基苯,并能够大幅度地提高重烷基苯的转换率,转化率能够达到83％以上,且目标产品C10-C13烷基苯的选择性能够达到80％以上,最高能够达到86％以上,所生产的产品无需进行二次分离,即可作为轻质烷基苯商品出售,作为其它产品的原料。(The invention discloses a heavy alkylbenzene anti-alkylation catalyst, which is prepared from the following raw materials: 25-85 wt% of a zeolitic molecular sieve; 15-75 wt% of a binder component. The application also discloses a preparation method and application of the catalyst. By utilizing the catalyst, heavy alkylbenzene can be efficiently subjected to reverse alkylation, the heavy alkylbenzene is converted into light alkylbenzene, the conversion rate of the heavy alkylbenzene can be greatly improved and can reach over 83%, the selectivity of a target product C10-C13 alkylbenzene can reach over 80% and can reach over 86% at most, and the produced product can be sold as a light alkylbenzene commodity without secondary separation and used as a raw material of other products.)

1. A heavy alkylbenzene anti-alkylation catalyst is characterized by being prepared from the following raw materials:

25-85 wt% of a zeolitic molecular sieve;

15-75 wt% of a binder component.

2. The heavy alkylbenzene reverse alkylation catalyst according to claim 1,

SiO of zeolite molecular sieve₂With Al₂O₃Is between 15 and 50.

3. The heavy alkylbenzene reverse alkylation catalyst according to claim 1,

specific surface area of zeolite molecular sieve 300-650m²The pore volume of the zeolite molecular sieve is 0.3-0.7 ml/g.

4. The heavy alkylbenzene reverse alkylation catalyst according to claim 1,

the binder is any one or a mixture of any two of alumina, silica and zirconia.

5. The process for preparing a heavy alkylbenzene reverse alkylation catalyst according to any one of claims 1 to 4, comprising the steps of:

(1) replacing alkali metal in the zeolite molecular sieve with ammonium salt solution, and then drying to prepare a hydrogen type molecular sieve;

(2) uniformly mixing the ammonia salt molecular sieve and a binder, adding nitric acid for kneading, extruding into strips for forming, and drying to prepare a catalyst blank;

(3) and roasting the catalyst green body in a muffle furnace, and cooling to obtain the strip catalyst.

6. The production method according to claim 5,

in the step (1), the content of alkali metal in the ammonia salt molecular sieve is 0-500 ppm.

7. The production method according to claim 5,

in the step (2), the concentration of the nitric acid is 5-15 wt%.

8. The production method according to claim 5,

in the step (3), the roasting temperature is 480-550 ℃, and the roasting time is 3-5 hours.

9. Use of the heavy alkylbenzene reverse alkylation catalyst according to any one of claims 1 to 5, characterised in that benzene and heavy alkylbenzene are catalytically converted into alkylbenzene with a molar ratio of benzene to heavy alkylbenzene of 1 to 10: 1.

10. use according to claim 9,

when benzene and heavy alkylbenzene are catalytically converted into alkylbenzene, a fixed bed reactor is adopted, the reaction temperature is 180 ℃, the reaction pressure is 0.03-4.0MPa, and the volume space velocity is 0.2-3h^-1。

Technical Field

The invention relates to a heavy alkylbenzene anti-alkylation catalyst, and a preparation method and application thereof.

Background

Linear alkylbenzenes are an important organic compound and one of the important basic raw materials for the synthesis of detergents. The existing linear alkylbenzene production technology is mainly a UOP HF method, and when linear olefin and benzene are subjected to alkylation reaction, some side reactions, such as polymerization, isomerization, chain scission disproportionation, double alkylation and the like, can occur, and the products of the side reactions are heavy alkylbenzene. The boiling range of the heavy alkylbenzene is relatively high (generally 310-470 ℃), and the heavy alkylbenzene is generally considered to be composed of a certain amount of monoalkylbenzene and impurities, such as dialkylbenzene, diphenylalkane, polyalkylbenzene, polyalkyl-alkane, dialkyl indane, tetralin and the like.

The heavy alkylbenzene has wide application, and is mainly used as raw materials of detergents, lubricating oil additives, guided hot oil, tertiary oil recovery oil-displacing agents, rubber fillers, lubricating oil base oil and the like. Although heavy alkylbenzene has a certain demand amount, the heavy alkylbenzene has low value, if the heavy alkylbenzene can be converted into other products with higher value, the added value of the products can be improved, at present, in the aspect of conversion of the heavy alkylbenzene, the heavy alkylbenzene is converted into monoalkylbenzene and alkyl tetralin, specifically, the heavy alkylbenzene, the benzene and aluminum trichloride are reacted according to a certain proportion, and the dialkylbenzene and the diphenylalkane in the heavy alkylbenzene are respectively disproportionated into the monoalkylbenzene and the alkyl tetralin. However, this technique has a low conversion rate, and can convert only some of the dialkylbenzene and diphenylalkane in the heavy alkylbenzene into components with strong detergency, but cannot utilize all of the heavy alkylbenzene.

Disclosure of Invention

In order to solve the above problems, the present application first proposes a heavy alkylbenzene anti-alkylation catalyst, which is prepared from the following raw materials: 25-85 wt% of a zeolitic molecular sieve; 15-75 wt% of a binder component, further preferably 60-80 wt% of a zeolitic molecular sieve; 20-40 wt% of a binder component. Specifically, the binder is any one or a mixture of any two of alumina, silica and zirconia.

The zeolite molecular sieve is a Lewis acid catalyst, has the characteristics of no corrosion, safety, environmental protection, adjustable activity and the like, and is an ideal environment-friendly catalyst. The catalyst can efficiently perform reverse alkylation on heavy alkylbenzene, and the heavy alkylbenzene is converted into light alkylbenzene, and the principle of the catalyst is that the zeolite molecular sieve has a uniform pore channel structure, so that the zeolite molecular sieve shows special selectivity by controlling the silica-alumina ratio and the ion exchange degree of the zeolite molecular sieve, and in the reaction process, the heavy alkylbenzene enters the pore channels of the zeolite molecular sieve and reacts under the action of acid, so that the heavy alkylbenzene is mainly converted into long-chain alkylbenzene and a small amount of short-chain alkylbenzene, and the added value of the product is improved.

Specifically, to improve the selectivity of C10-C13 alkylbenzene, SiO of the zeolite molecular sieve₂With Al₂O₃Is between 15 and 50. It was found that SiO₂With Al₂O₃The lower the conversion of heavy alkylbenzene, the less the selectivity of C10-C13 alkylbenzene, when the molar ratio of (A) is too high, the difference between them being small₂With Al₂O₃Too high a molar ratio of (b) may result in a decrease in the conversion of heavy alkylbenzene. The reasons for this may be: SiO of zeolite molecular sieve₂With Al₂O₃The mole of the silicon-aluminum compound affects the acidity of the catalyst, the silicon-aluminum ratio is low, the acidity is strong, the silicon-aluminum ratio is high, the acidity is weak, and the conversion rate of raw materials is affected.

Specifically, to ensure sufficient contact area between the catalyst and the reactant, the specific surface area of the zeolite molecular sieve is 300-650m²The pore volume of the zeolite molecular sieve is 0.3-0.7 ml/g. Preferably, the zeolite molecular sieve has a specific surface area of 500-600m²Preferably, the pore volume is 0.4 to 0.55 ml/g.

Tests show that when the specific surface area of the zeolite molecular sieve is too low, the benzene and the heavy alkylbenzene are not completely contacted, the reaction conversion rate is low, and when the specific surface area is too large, the benzene and the heavy alkylbenzene are contacted for too long, so that the selectivity of a target product is reduced. The proper pore volume can ensure that a proper amount of benzene is contacted with heavy alkylbenzene to ensure the smooth reaction, when the pore volume is too large, the contact time of the benzene and the heavy alkylbenzene is too long, the selectivity of a target product is reduced, and when the pore volume is too low, the benzene and the heavy alkylbenzene are not completely contacted, and the reaction conversion rate is low.

Secondly, the present application also provides a preparation method of any one of the heavy alkylbenzene anti-alkylation catalysts, which comprises the following steps:

(1) replacing alkali metal in the zeolite molecular sieve with ammonium salt solution, and then drying to prepare the ammonia salt molecular sieve;

(2) uniformly mixing the ammonia salt molecular sieve and a binder, adding nitric acid for kneading, extruding into strips for forming, and drying to prepare a catalyst blank;

(3) and roasting the catalyst green body in a muffle furnace, and cooling to obtain the strip catalyst.

In addition, before the calcination, the catalyst blank is preferably dried at the temperature of 100-200 ℃ so that most of water in the catalyst blank can be removed and the crushing phenomenon after the calcination process is avoided.

In the preparation method, the zeolite molecular sieve is firstly subjected to alkali metal replacement to reduce alkali metal in the zeolite molecular sieve, the acidity of the zeolite molecular sieve is further adjusted, then nitric acid is used for kneading, and finally roasting is carried out. By utilizing the preparation method, firstly, replacement is carried out, then roasting is carried out, and when the catalyst has problems, the reasons of the problems can be quickly judged.

Further, in order to ensure the activity of the catalyst, in the step (1), the content of alkali metal in the ammonia salt molecular sieve is 0-500 ppm.

Further, in the step (2), the concentration of nitric acid is 5 to 15 wt%. The amount of nitric acid used is 2 to 15 wt.%, preferably 3 to 8 wt.%, based on pure nitric acid, of the catalyst. The nitric acid is used for bonding other raw materials together, the property of the catalyst is not influenced, but the strength of the best catalyst product is influenced, the dosage of the nitric acid is too low, the raw materials cannot be well fused, the strength of the sintered catalyst is too low, the dosage of the nitric acid is too large, on one hand, equipment is corroded, and on the other hand, a large amount of acid gas generated in the drying and calcining steps influences the health of workers and pollutes the environment. In addition, the concentration of the nitric acid is too high, and the concentrated nitric acid has strong corrosivity and is difficult to control.

Further, in the step (3), the roasting temperature is 480-550 ℃, and the roasting time is 3-5 hours.

Under the conditions, the total acid content of the catalyst can be ensured, and the template agent, ammonium ions and the like in the zeolite molecular sieve are all calcined.

The application also provides the application of the heavy alkylbenzene anti-alkylation catalyst, in particular to the application of the heavy alkylbenzene anti-alkylation catalyst for catalytically converting benzene and heavy alkylbenzene into alkylbenzene, wherein the molar ratio of the benzene to the heavy alkylbenzene is 1-10: 1.

Concretely, when benzene and heavy alkylbenzene are catalytically converted into alkylbenzene, a fixed bed reactor is adopted, the reaction temperature is 180-^-1. Preferably, the reaction temperature is 200 ℃ and 280 ℃, the reaction pressure is 2.0-4.0MPa, and the volume space velocity is 0.5-1.5h^-1。

Under the reaction conditions, the conversion rate of heavy alkylbenzene can be greatly improved, the conversion rate can reach more than 83 percent, the selectivity of the target product C10-C13 alkylbenzene can reach more than 80 percent and can reach more than 86 percent at most, and the produced product can be sold as a light alkylbenzene commodity without secondary separation and used as a raw material of other products.

During specific production, the heavy alkylbenzene is cut in sections by adopting a light component removal tower and a heavy component removal tower. Separating light alkylbenzene with the carbon number below 9 in a light component removal tower, wherein the light component can be used as a raw material of a detergent after sulfonation; the intermediate component (H2HAB heavy alkylbenzene) with the component of C10-13 alkylbenzene is generally used as the raw material of lubricating oil additive to be sulfonated; heavy alkylbenzene (H3HAB) larger than C13 is separated in a heavy component removing tower, and the heavy component can be used as a blending component of lubricating oil base oil with low condensation point and high viscosity to produce heavy alkylbenzene sulfonate products, and can also be used for carrying out transalkylation (reverse alkylation) reaction with benzene to produce low-carbon alkylbenzene and general monoalkylbenzene, so that the yield of detergent alkylbenzene is increased, and the method also has better economic benefit.

Drawings

FIG. 1 is a chromatogram of heavy alkylbenzene in example 3.

FIG. 2 is a gas-mass plot of the reaction product of example 3.

Detailed Description

Example 1

Adding 100g of zeolite molecular sieve into 10-15 wt% ammonium chloride solution, repeating the solution-solid ratio of 4 and the exchange temperature of 90 ℃ for three times, and reducing Na ions of the zeolite molecular sieve to be below 500ppm to prepare the hydrogen type zeolite molecular sieve. In the present application, the liquid-solid ratio is the mass ratio of the ammonium chloride solution to the zeolite molecular sieve.

Mixing a hydrogen type zeolite molecular sieve and alumina according to a dry basis mass ratio of 70: 30, wherein the specific surface area of the hydrogen type zeolite molecular sieve is 500-600m²Per g, pore volume of 0.4-0.55ml/g, SiO₂/Al₂O₃The molar ratio is 20, then 50g of nitric acid solution with the concentration of 15 wt% is added for full kneading, strip extrusion molding and air drying are carried out, then drying is carried out at 120 ℃, and then roasting is carried out in a muffle furnace at 520 ℃ for 3 hours to prepare the heavy alkylbenzene anti-alkylation catalyst, wherein the heavy alkylbenzene anti-alkylation catalyst has the following numbering: FTH-1.

Example 2

100g of zeolite molecular sieve is added into 10-15% ammonium chloride solution, the liquid-solid ratio is 4, the exchange temperature is 90 ℃, the process is repeated for three times, and the Na ion of the zeolite molecular sieve is reduced to be below 500 ppm.

Mixing a hydrogen type zeolite molecular sieve and alumina according to a dry basis mass ratio of 70: 30, wherein the specific surface area of the hydrogen type zeolite molecular sieve is 500-600m²Per g, pore volume of 0.4-0.55ml/g, SiO₂/Al₂O₃The molar ratio is 30, then 50g of nitric acid solution with the concentration of 15% is added for full kneading, strip extrusion molding and air drying are carried out, then drying is carried out at 120 ℃, and roasting is carried out in a muffle furnace at 520 ℃ for 3 hours to prepare the catalyst, wherein the serial numbers are as follows: FTH-2.

In the following examples, the heavy alkylbenzene and benzene used were those produced by the tomb division of petrochemical company, ltd, china.

Example 3

Catalyst FTH-1 was ground to 20-40 mesh particles and 10ml was loaded into a fixed bed pilot plant.

Benzene to heavy alkyl in a 5:1 molar ratioBenzene is used as a raw material, and the reaction temperature is as follows: at 220 ℃, under pressure; 2.0MPa, volume space velocity: 0.8h^-1The reaction product was analyzed by a chromatograph, and the conversion of heavy alkylbenzene was 83.2%, the selectivity to C5 alkylbenzene was 2.0%, the selectivity to C5-C9 alkylbenzene was 13.1%, and the selectivity to C10-C13 alkylbenzene was 84.9%.

FIGS. 1 and 2 are gas-mass spectrometry spectra of heavy alkylbenzene and the reaction product used in this example, respectively. The gas-mass spectrometry is short for gas chromatography-mass spectrometry.

As can be seen from FIG. 1, the proportion of C13 alkylbenzene at position 2 is 2.82 wt%, and the rest is C13 alkylbenzene or above.

The product of this example was subjected to gas-mass analysis, and the ratio of time to ingredients is shown in Table 1.

TABLE 1

Product distribution	Time min	The content wt%
			C9-light alkylbenzenes	3.94-10.89	14.21
C10-13 alkyl benzene	11.65-15.06	61.19
			2-C13 alkyl benzene	15.55	7.80
H2HAB heavy alkylbenzene	16.09-	16.80

In Table 1, C9-light alkylbenzenes represent alkylbenzenes having 9 or less than 9 carbon atoms; c10-13 alkylbenzene is C10-13 alkylbenzene, 2-C13 alkylbenzene is C13 alkylbenzene at 2-position, and H2HAB heavy alkylbenzene is unreacted heavy alkylbenzene.

Example 4

Catalyst FTH-1 was ground to 20-40 mesh particles and 10ml was loaded into an evaluation apparatus.

Benzene and heavy alkylbenzene with a molar ratio of 10:1 are used as raw materials, and the reaction temperature is as follows: at 220 ℃, under pressure; 2.0MPa, volume space velocity: 0.8h^-1The reaction product is analyzed by a chromatograph, the conversion rate of heavy alkylbenzene is 75.1%, the selectivity of C5 alkylbenzene is 4.1%, the selectivity of C5-C9 alkylbenzene is 10%, and the selectivity of C10-C13 alkylbenzene is 85.9%.

Example 5

Catalyst FTH-2 was ground to 20-40 mesh particles and 10ml was loaded into an evaluation apparatus.

Benzene and heavy alkylbenzene with a molar ratio of 5:1 are used as raw materials, and the reaction temperature is as follows: at 220 ℃, under pressure; 2.0MPa, volume space velocity: 0.8h^-1The reaction product is analyzed by a chromatograph, the conversion rate of heavy alkylbenzene is 76.5 percent, the selectivity of C5 alkylbenzene is less than 1.5 percent, the selectivity of C5-C9 alkylbenzene is 18.5 percent, and the selectivity of C10-C13 alkylbenzene is 80 percent.

Comparative example 1

Catalyst FTH-1 was ground to 20-40 mesh particles, 10ml of which was removed and loaded into an evaluation apparatus.

Benzene and heavy alkylbenzene with a molar ratio of 5:1 are used as raw materials, and the reaction temperature is as follows: at 220 ℃, under pressure; 0MPa, volume space velocity: 0.8h^-1The reaction product is analyzed by a chromatograph, the conversion rate of heavy alkylbenzene is 78.1%, the selectivity of C5 alkylbenzene is 16.1%, the selectivity of C5-C9 alkylbenzene is 63%, and the selectivity of C10-C13 alkylbenzene is 20.9%.

Comparative example 2

The beta zeolite catalyst was prepared in the same manner, ground to 20-40 mesh particles, and 10ml of the particles were removed and charged into an evaluation apparatus.

Benzene and heavy alkylbenzene with a molar ratio of 5:1 are used as raw materials, and the reaction temperature is as follows: at 220 ℃, under pressure; 2.0MPa, volume space velocity: 0.8h^-1The reaction product was analyzed by a chromatograph, and the conversion of heavy alkylbenzene was 85.6%, the selectivity to C5 alkylbenzene was 5.7%, the selectivity to C5-C9 alkylbenzene was 67.3%, and the selectivity to C10-C13 alkylbenzene was 27.0%.

As can be seen from the above examples and comparative examples, the catalyst produced by the present application can effectively improve the anti-alkylation effect of heavy alkylbenzene, and the main active ingredient C5-C9 alkylbenzene in the obtained product has high selectivity. The catalyst prepared in the invention has the advantages that the actual yield of the C10-C13 alkylbenzene is only about 23% due to the low selectivity of the C10-C13 alkylbenzene, while the conversion rate of the heavy alkylbenzene is high in the conventional catalyst in the comparative example 2, and the actual yield of the C10-C13 alkylbenzene can reach 61-73% which is 2.6-3.2 times that of the prior art.

The catalyst prepared in the present application was used in comparative example 1, but the selectivity of C10-C13 alkylbenzene was reduced to 20.9% due to the lower reaction pressure, and the yield of C10-C13 alkylbenzene was only 16.3% although the conversion of heavy alkylbenzene was not much different from that of the examples.