CN1077808C - Catalyst of alkyl benzene with straight chain made by alkylation from benzene and straight chain olefin and its application - Google Patents

Abstract

The present invention relates to an HY type molecular sieve catalyst for preparing linear alkyl benzene (LAB) from C10 to C14 straight chain olefins and benzene in an alkylation mode, which is processed in a metal ion exchange mode and treated by acid. Straight chain olefins can react with benzene in an alkylation mode with a high conversion rate so as to be converted into linear alkyl benzene with high selectivity; the reaction condition comprises: the reaction temperature is from 120 to 300 DEG C, the reaction pressure is from 1.0 to 5.0MPa, the weight space velocity of the reaction is from 1 to 20h<-1>, and the molar ratio of benzene to olefin is from 0.5: 1 to 25: 1. The HY type molecular sieve catalyst has the advantages of simple preparation method and suitable weight; the HY type molecular sieve catalyst can be directly regenerated on a reaction apparatus under the same reaction condition by using the simple technique of washing with benzene and alkanes.

Description

Catalyst for Alkylation of Benzene and Linear Olefin to Produce Linear Alkylbenzene and Its Application

The invention relates to a Y-type zeolite molecular sieve catalyst which undergoes ion exchange and acid treatment to produce linear alkylbenzene (LAB) by alkylation of C ₁₀ -C ₁₄ linear olefins and benzene. On this catalyst, C ₁₀ ~ C ₁₄ linear olefins can be converted into linear alkylbenzene with high conversion rate and high selectivity in the alkylation reaction of benzene, and the preparation method of the catalyst is simple, the reproducibility is good, and the catalyst has high activity and selectivity, catalytic reaction stability and regeneration performance.

Traditional Friedel-Crafts type reactions, such as the alkylation of aromatic hydrocarbons and linear olefins, mainly use Lewis acids such as AlCl ₃ , BF ₃ , H ₂ SO ₄ , H ₃ PO ₄ , and HF as catalysts. For C ₁₀ ~C ₁₄ Alkylation of linear olefins and benzene to produce linear alkylbenzenes, using the above-mentioned traditional catalysts will generate 2-, 3-, 4-, 5-etc. isomers of alkylbenzenes. Taking the _AlCl3 catalyst as an example, the reaction product of _C12 linear olefins and benzene to alkylbenzenes contains various isomers, and the selectivity of 2-alkylbenzenes is 30%, because 2-alkane Alkylbenzene has the best biodegradability and is the most needed product in industry. Therefore, the developed catalyst is required to have a higher selectivity of 2-alkylbenzene isomers. At present, the most commonly used HF catalyst in the industry has a selectivity of ₂ -alkylbenzene in the reaction product of C ₁₂ straight-chain olefins and benzene alkylation to produce _alkylbenzene , which is only about ₂₀ %. Alkylation of alkenes with benzene can achieve 41% 2-alkylbenzene selectivity. However, the above-mentioned HF, H ₂ SO ₄ and other homogeneous acid catalysts are particularly corrosive to equipment, and the catalyst is not easy to recycle or recycle. For this reason, chemists are constantly researching to develop non-corrosive to reaction equipment, and easy Regenerated or recovered solid acid catalyst.

Since the early 1980s, chemists began to study heterogeneous catalysts for the production of linear alkylbenzenes by Friedel-Crafts reactions, and great progress has been made. For example, USPat4477585, 4547605, 4301317, etc. use ZSM series molecular sieves as catalysts, and achieve a conversion rate of olefins of 94%, and a selectivity of LAB of 73%. ≥98%, good result of LAB selectivity 85%; CN1072353 adopts ion-exchanged Y-type molecular sieve as catalyst, can reach olefin conversion > 99%, good result of LAB selectivity 99%, but its catalyst life is very short, its Catalyst regeneration is frequent; USPat5157158 uses silica-alumina, or magnesium silicate modified with multivalent metal ions, or the catalyst is treated with H ₂ SO ₄ , HF and other acids, the conversion rate of olefins is >95%, and the selectivity of LAB is greater than 85%. The one-way life is more than 300 hours.

The purpose of the present invention is to provide a catalyst for preparing straight-chain alkylbenzenes by alkylation of benzene and C ₁₀ to C ₁₄ straight-chain olefins, the preparation method of the catalyst and the use of this catalyst to carry out C ₁₀ to C ₁₄ straight-chain olefins and Benzene alkylation reaction.

The catalyst of the present invention adopts HY molecular sieve catalyst modified by metal ions, that is, MHY molecular sieve catalyst, and the metal ion is one or more of Fe ³⁺ , Zr ⁴⁺ , Ti ⁴⁺ , alkaline earth metal ions or rare earth metal ions. ions, the weight content of metal ions is 0.01-2.5%. In addition, in order to change the catalytic performance of the catalyst for the reaction, especially to improve the service life of the catalyst, the catalyst MHY molecular sieve of the present invention is treated with acid to adjust the distribution of the acid center of the catalyst. The acid used is H ₂ SO ₄ , NH ₄ HSO ₄ , H ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ , NH ₄ H ₂ PO ₄ , HNO ₃ , HCl, H ₃ BO ₃ , HF, NH ₄ F, or HF+NH ₄ F, to prepare a modified MHY molecular sieve catalyst. The preparation process of the catalyst of the present invention is carried out according to the following steps.

1. Forming Na-Y molecular sieves into tablets or adding a binder. When the binder is added for molding, Al ₂ O ₃ , SiO ₂ , ZrO ₂ , TiO ₄ , MgO, CaO, kaolin, montmorillonite, One or more of bentonite and other binders are mechanically mixed with 0.5-6.0M HNO ₃ to shape the catalyst, and the molding process can be carried out by conventional methods.

2. According to the ratio of 2-30ml/g, mix 0.2-2.0M NH ₄ NO ₃ solution with molecular sieves, perform ion exchange with Na-Y molecular sieves at 50-100°C for 1-4 times, and use distilled water (2-20ml /g molecular sieve) after washing for 1 to 4 times, drying at 120°C for 1 to 3 hours, and roasting at 400 to 700°C for 1 to 6 hours to obtain HY molecular sieves. The residual amount of Na ions in HY molecular sieves should be less than 10%. The above-mentioned HY molecular sieve can also be prepared by performing ion exchange with dilute acid and NaY molecular sieve according to the ion exchange method of conventional molecular sieves.

3. According to the ratio of 2-30ml/g, mix the above-mentioned HY molecular sieve with 0.5-2.0M alkaline earth metal ions, rare earth metal ions, and nitrates of one or more ions in Fe ³⁺ , Zr ⁴⁺ , Ti ⁴⁺ Mix the solutions, perform ion exchange for 1-4 times under stirring at 50-100°C, wash with distilled water for 1-4 times, dry at 60-120°C for 1-10 hours, and roast at 400-700°C for 1-10 hours, that is The metal ion molecular sieve MHY was obtained.

4. Mix the above-mentioned MHY molecular sieve with 0.1-6M H ₂ SO ₄ , NH ₄ HSO ₄ , H ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ , HNO ₃ , HCl, H ₃ at a ratio of 2-30ml/g Mix one or several solutions of BO ₃ , HF, NH ₄ F, or NH ₄ F, react at 20°C-100°C for 0.3-20 hours, then pour off the excess solution, and dry at 60-120°C 1 to 10 hours, 400°C to 700°C roasting for 1 to 10 hours, repeat 2 to 4 times to obtain the acid-treated MHY molecular sieve catalyst. The catalyst prepared in this way has very high olefin conversion rate and very high LAB selectivity of straight-chain olefins and benzene alkylation reaction to produce linear alkylbenzene, and the catalyst has good catalytic stability; olefin per pass conversion rate reaches 97 ～99%, the selectivity of LAB reaches 90～99%, and the selectivity of 2-alkylbenzene isomers can reach about 30%, and the single-pass life of the catalyst reaches 150～300 hours.

When using a fixed-bed reactor to carry out the above reaction, the reaction conditions are: benzene and C ₁₀ ~ C ₁₄ olefins are mixed feed, benzene olefin molecular ratio = 0.5/1 ~ 25/1, and the feed space velocity is 1 ~ 20h ^{- 1.} The reaction temperature is 120-300°C, and the reaction pressure is 0.5-5MPa.

In addition, the regeneration of the deactivated catalyst of the present invention adopts the following method:

Use a mixed solution of benzene and C ₁₀ ~ C ₁₃ normal alkanes (at a molar ratio of 1:1 ~ 10:1) to wash away the carbon deposits and regenerate the catalyst activity. The regeneration conditions are: the temperature is 100 ~ 300 ° C, the best 120°C-250°C, pressure 0.5-5.0MPa, preferably 1.0-3.5MPa, mixed feed space velocity 1.0-20.0h ^-1 , regeneration 1-20h.

Below by example the content of the present invention is given detailed description:

The preparation of embodiment 1 ion exchange type HY molecular sieve

Press 100g of Na-Y molecular sieve into tablet form, add 1000mk1.0M NH ₄ NO ₃ solution (water bath at 80-90°C), perform ion exchange 3 times, and wash 3 times with 1000ml distilled water at the same temperature, then, After baking at 120°C for 2 hours and then at 550°C for 4 hours, the hydrogen-form HY molecular sieve A ₁ is obtained. 20 g of kaolin was added to 100 g of Na-Y molecular sieve, mixed and molded, and ion exchange was carried out in the same manner as above to obtain HY molecular sieve A ₂ containing a binder.

Embodiment 2 metal ion exchange catalyst B, C, D, the preparation of E and F

Take 20g of molecular sieve A ₁ and mix it with 2000ml of 0.5M Sr(NO ₃ ) ₂ solution, conduct ion exchange twice at 80-90°C, wash with 800ml of distilled water for 4 times, bake at 120°C for 2 hours, and roast at 550°C for 4 hours. This was repeated 4 times to obtain catalyst B ₁ . Take 20 g of molecular sieve A ₂ and repeat the above method to prepare catalyst B ₂ . Using the same method, molecular sieves A ₁ and A ₂ were respectively taken and exchanged with 0.25M La(NO ₃ ) ₃ solution to obtain catalysts C ₁ and C ₂ . Take 20g of molecular sieve A ₁ , exchange it with 100ml of 0.5M Sr(NO ₃ ) ₂ solution + 100ml of 0.25M La(NO ₃ ) ₃ solution to obtain catalyst D. Molecular sieve A ₁ was taken and exchanged with 0.25M Fe(NO ₃ ) ₃ solution according to the above method to obtain catalyst E. Molecular sieve A ₂ was taken and exchanged with 0.5M Zr(NO ₃ ) ₄ solution according to the above method to obtain catalyst F.

Embodiment 3 (NH ₄ ) Preparation of ₂ HPO ₄ Modified Catalysts

Treat 10g of catalyst D with 100ml of 0.1M (NH ₄ ) ₂ HPO ₄ solution at 80°C for 2h, pour off the remaining solution, bake at 120°C for 2h, and bake at 550°C for 3h, and repeat once to obtain catalyst D1.

Embodiment 4H ₃ PO ₄ Preparation of the modified catalyst

Treat 10g of catalyst _C1 with 100ml of 0.1M H ₃ PO ₄ solution at 80°C for 2h, pour off the remaining solution, bake at 120°C for 2h, and bake at 550°C for 3h, and repeat once to obtain catalyst C1. Catalyst F was treated in the same manner as above to obtain catalyst F1.

Example 5 Benzene reacts with 1-dodecene to prepare dodecylbenzene experiment 1

Put molecular sieve A2g into a reaction tube with an inner diameter of 9mm in the reactor, activate it at 350°C for 1h under 200ml/min _N2 purging, pump in 20ml of 4A molecular sieve and silica gel in advance at a space velocity of 20h ^-1 Dehydrated benzene to fill the entire reaction system, then raise the temperature of the reactor to 100°C, and pump 20ml of benzene mixed raw material dehydrated with 4A molecular sieve and silica gel in advance at a space velocity of 20h ^-1 , so as to fully replace the benzene in the reaction system , and finally raised the temperature to 170°C, under the reaction conditions of benzene/1-dodecene molecular ratio = 15/1, space velocity of 4h ^-1 , and reaction pressure of 2.8MPa, the alkylation reaction between benzene and olefin was carried out, and the reaction The results are shown in Table 1. The above experiments were repeated using catalysts _B1 and _B2 respectively, and the reaction results are shown in Table 1.

Example 6 Benzene reacts with 1-dodecene to prepare dodecylbenzene experiment 2

Catalyst C ₁ 2g is packed in the reaction tube of internal diameter 9mm of reactor, after catalyst C ₁ is processed under the pretreatment conditions such as catalyst activation identical with embodiment 5, adopt the operating procedure identical with embodiment 5 and as follows Conditions, that is, under the conditions of 180°C, mixed raw materials (benzene/1-dodecene=18/1) _, space velocity of 6h ^-1 , and reaction pressure of 3.4MPa, the reaction of benzene and C ₁₂ olefins is carried out on the catalyst C1 Performance evaluation, the reaction results are shown in Table 1. The above experiment was repeated with catalyst _C2 instead of _C1 , and the reaction results are shown in Table 1.

Example 7 The reaction of benzene and 1-dodecene to prepare dodecylbenzene experiment 3

Catalyst D2g is packed in the reaction tube of reactor inner diameter 9mm, after catalyst D is processed under the pretreatment conditions such as catalyst activation identical with embodiment 5, adopt the operating procedure identical with embodiment 5 and following condition, namely Under the conditions of 190°C, mixed raw materials (benzene/1-dodecene=12/1), space velocity of 2h ^-1 , and reaction pressure of 2.2MPa, catalyst D was evaluated for the reaction performance of benzene and C ₁₂ olefins, The reaction results are shown in Table 1. The above experiment was repeated with catalyst DI instead of D, and the reaction results are shown in Table 1.

Embodiment 8 Benzene reacts with 1-dodecene to prepare dodecylbenzene experiment 4

Catalyst E2g is packed in the reaction tube of reactor internal diameter 9mm, after catalyst E is processed under the pretreatment conditions such as catalyst activation identical with embodiment 5, adopt the operating procedure identical with embodiment 5 and following condition, i.e. Under the conditions of 170°C, mixed raw materials (benzene/1-dodecene=12/1), space velocity of 4h ^-1 , and reaction pressure of 3.2MPa, catalyst E was evaluated for the reaction performance of benzene and C ₁₂ olefins, The reaction results are shown in Table 1. The above experiment was repeated with catalyst EI instead of E, and the reaction results are shown in Table 1.

Embodiment 9 Benzene reacts with 1-dodecene to prepare dodecylbenzene experiment 5

Catalyst F2g is packed in the reaction tube of internal diameter 9mm of reactor, after catalyst F is processed under the pretreatment conditions such as catalyst activation identical with embodiment 5, adopt the same operation program and following conditions with embodiment 5, namely Under the conditions of 180°C, mixed raw materials (benzene/1-dodecene=16/1), space velocity of 6h ^-1 , and reaction pressure of 3.0MPa, catalyst F was evaluated for the reaction performance of benzene and C ₁₂ olefins, The reaction results are shown in Table 1. The experiment was repeated with catalyst FI instead of F, and the reaction results are shown in Table 1.

The regeneration experiment of embodiment 10 catalyst

The catalyst FI deactivated by the alkylation reaction of benzene and 1-dodecene in Example 9 is washed with a mixed solution of benzene and n-octane with a molar ratio of 3/1 to regenerate the catalyst. The regeneration conditions are: temperature The pressure at 150°C is 2.8MPa, the space velocity of the mixed feed is 4.0h ^-1 , and the regeneration time is 8h.

Example 11 Regeneration of Catalyst Benzene and 1-Dodecene to Prepare Dodecylbenzene Experiment 6

Catalyst EI 2g after regeneration is packed in the reaction tube of reactor inner diameter 9mm, after catalyst EI is processed under the pretreatment conditions such as catalyst activation identical with embodiment 5, adopt the operating procedure identical with embodiment 8 and Reaction conditions, that is, at 170°C, mixed raw materials (benzene/1-dodecene = 12/1), space velocity of 4h ^-1 , and reaction pressure of 3.2MPa, the regenerated catalyst EI is subjected to benzene and C ₁₂ Evaluation of olefin reaction performance, the reaction results are shown in Table 1.

Table 1 Example Catalyst Benzene/1-Dodecene Reaction Results of Dodecylbenzene Reaction Example Catalyst 1-Dodecene to Linear Dodecyl Dodecylbenzene 2-Dodecylbenzene Catalyst

Conversion rate (%) Benzene selectivity (%) Linearity (%) Selectivity (%) Stability (h)5 A 97.73 94.42 97.79 26.43 605 B ₁ 97.06 94.95 97.69 27.14 1005 B ₂ 96.49 93.99 98.00 27.09 1106 C _{2 1} 9 91.68 97.34 25.93 1006 C ₂ 98.98 92.41 98.02 26.41 1207 D 99.73 92.37 98.46 29.59 1007 DI 98.04 96.98 98.45 29.41 ＞2008 E 97.36 96.59 98.21 29.59 1008 EI 96.27 95.44 97.96 28.93 ＞2109 F 97.84 93.45 98.12 26.65 1009 FI 96.10 94.24 97.91 27.01 ＞21011 Regeneration EI 97.50 96.12 98.19 29.41 ＞200

By above-mentioned example, catalyst preparation method of the present invention is simple, and reproducibility is good, and catalyst has higher activity and selectivity and catalytic reaction stability, and easy regeneration and recovery, and the regeneration process of catalyst is simple, can react with reaction on the same device , carried out under the same conditions as the reaction, which saves time and energy, and the alkylation reaction product of benzene and C ₁₀ ~ C ₁₄ olefins using this catalyst can be used to produce detergents with better biodegradability and emulsification, so that Improving product quality and reducing environmental pollution have great economic and social benefits.

Claims (4)

1. A Y molecular sieve catalyst used for the alkylation reaction of benzene and C ₁₀ ~ C ₁₄ linear olefins to produce linear alkylbenzene, characterized in that it is MHY, and M is metal ion Fe ³⁺ , Zr ⁴⁺ , Ti ⁴⁺ , one or more ions of alkaline earth metal ions or rare earth metal ions, the weight content of metal ions is 0.01-2.5%; it can be obtained by treating with 0.1-6M acid at 20-100°C for 0.3-20 hours MHY molecular sieve catalyst. 2. A method for preparing the catalyst according to claim 1, characterized in that after ion exchange with 0.1 to 3.0M NH ₄ ⁺ salt aqueous solution to obtain HY molecular sieve, then use one or several 0.1 to 6.0M The aqueous solution of alkaline earth metal ions, rare earth metal ions, Fe ³⁺ , Zr ⁴⁺ or Ti ⁴⁺ ions is ion-exchanged, treated with acid, dried and roasted to obtain the catalyst; Down treatment for 0.3-20 hours, then drying at 60-120°C for 1-10 hours, and roasting at 400-700°C for 1-10 hours. 3. A method for alkylation of the catalyst according to claim 1, characterized in that the reaction conditions are: the reaction temperature is 120-300°C, the reaction pressure is 0.5-5.0Mpa, and the reaction weight space velocity is 1-20h ^{- 1.} Benzene/olefin (molar ratio) is 0.5/1-25/1. 4. according to the regeneration method of catalyst described in claim 1, it is characterized in that catalyst regeneration method is to use benzene and C ₁₀ ～C ₁₃ n-paraffins to wash and remove carbon deposits by the mixed solution of 1:1～10:1 molar ratio The catalyst activity is regenerated, and the regeneration conditions are as follows: the temperature is 100-300°C, the pressure is 0.5-5.0MPa, the space velocity of the mixed feed is 1.0-20.0h ^-1 , and the regeneration is 1-20h.