CN1048198C - Catalyst using for process of ether and its processing method - Google Patents

Abstract

The invention relates to a modified hydrogen-type zeolite catalyst for methyl tert-butyl ether (MTBE) and isopropyl ether (IPE) and a preparation method thereof. The modified hydrogen-type zeolite catalyst of the present invention consists of hydrogen-type β Zeolite (50-100 parts by weight), gamma-alumina (0-50 parts by weight) and boron oxide (0.5-25 parts by weight). The preparation method comprises three processes: preparation of hydrogen type β zeolite; preparation of hydrogen type β zeolite and aluminum oxide strip mixture; impregnation of boron oxide. The catalyst of the present invention has high catalytic activity and selectivity for the synthetic reaction of MTBE or IPE, especially has little influence on the reaction temperature change, no pollution to the environment, no corrosion to the reaction equipment, easy regeneration, good stability, and easy preparation Etc.

Description

A kind of novel catalyst for the preparation of ether and preparation method thereof

The invention relates to a catalyst containing zeolite molecular sieve, aluminum oxide and boron oxide and a preparation method thereof.

At present, most of the catalysts used in the preparation of methyl tert-butyl ether and isopropyl ether at home and abroad are strong acid cation exchange resins, such as Amberlyst-15, D72 and so on. This type of catalyst is sensitive to temperature changes. If the reaction temperature exceeds 90°C, the active components will be obviously lost, and at the same time, it will cause corrosion to the equipment and pollution to the environment. It is easy to dissolve and swell during the reaction process, and cannot be regenerated (Chu, P., Ind.Eng.Chem.Res., 1987, 26(2), 365-369; Qian Ruilong, Petrochemical Chemical Fiber, 4, 12-21, 1992). There are also titanium and zirconium series heteropolyacids and phosphoric acid catalysts. The biggest disadvantage of this type of catalyst is that the by-product content of the reaction is very large (JP 54, 55507A ₂ , JP 01, 283234A ₂ ). Although some people have begun to study the use of molecular sieve catalysts, mainly using hydrogen-type ZSM-5 and Y molecular sieves, hydrogen-type zeolite beta is also introduced, mainly to study the technical problems of the reaction, and no good results have been obtained on catalysts. effect, the main problem is that the catalytic activity is not high enough (Chu, P., Ind.Eng.Chem.Res., 1987, 26 (2), 365-369; Goodwin, Jr.JG, J.Catal., 1994, 148, 1557-163; USP5,114,086)

The purpose of this invention is to provide a kind of can be used for the preparation of methyl tert-butyl ether (MTBE) or isopropyl ether (IPE), there is higher catalytic activity, is little affected by the reaction temperature change, has good selectivity again simultaneously , Easy to regenerate and good stability modified hydrogen type β zeolite catalyst.

The object of the present invention is achieved in this way: the present invention is a composite modified hydrogen type β zeolite composed of hydrogen type β zeolite (Hβ), γ-alumina (γ-Al ₂ O ₃ ) and boron oxide (B ₂ O ₃ ). The zeolite catalyst has a component weight ratio of Hβ:γ-Al ₂ O ₃ :B ₂ O ₃ =50-100:0-50:0.5-25.

The catalyst component weight ratio of the present invention is preferably in the range of Hβ:γ-Al ₂ O ₃ : _{B 2} O ₃ =70-90:10-25:1-7.

The preparation method of the catalyst of the invention comprises three steps of preparation of hydrogen type zeolite beta, preparation of mixture of hydrogen type beta zeolite and aluminum oxide strips and impregnation of boron oxide.

(1) Preparation of hydrogen-type zeolite beta: a certain amount of sodium-type beta zeolite is exchanged 4 times at 90°C with a sufficient amount of ammonium chloride solution of 1.0 normal concentration (each exchange time is maintained for 2 hours), and the The zeolite after the exchange reaction was calcined at 550° C. for 4 hours to obtain the hydrogen β zeolite.

(2) Preparation of hydrogen-type zeolite beta and alumina strip mixture: get the hydrogen-type zeolite beta that is 50～100 parts by weight and the solid content that is 10% (percentage by weight) is 0～100 parts. 500 parts by weight of aluminum glue are mixed, adding a concentration of 2% HNO solution until the solid mixture _is completely wetted, adding 3% starch by weight of the mixture of hydrogen type zeolite and aluminum glue, mixing them evenly and pressing Form into strips, dry at 120°C for 4-12 hours, the diameter of the strips is 2mm, and the length is not limited.

(3) impregnating boron oxide, getting a certain gravimetrically analyzed pure boric acid solution in the deionized water of the proportioning amount to make the boric acid content is an aqueous solution of 10.0% (weight), and the required amount of hydrogen obtained in (2) step The strip mixture of type β zeolite and alumina is diluted with 10.00% boric acid solution to 0.1% to 10.00% boric acid solution for impregnation, each impregnation is 12 hours, and after each impregnation, it must be dried below 100°C. The modified hydrogen-type zeolite beta catalyst with the composition Hβ:γ-Al ₂ O ₃ :B ₂ O ₃ =50～100:0～50:0.5～25 thus obtained is then heated at 200°C to 850°C Roast for 1 to 20 hours and store in a desiccator to prevent moisture absorption and set aside.

Compared with the prior art, the present invention has the following advantages: A. High catalytic activity. The modified hydrogen type beta zeolite catalyst of the present invention has high catalytic activity for the synthesis of MTBE or IPE. In the reaction of synthesizing MTBE, the catalytic activity is equivalent to that of Amberlyst-15 (Am-15), which is recognized as the best catalytic activity in the world at present (see accompanying drawing 2). Comparable to propylene conversion on anhydrous _AlCl3 in the synthetic IPE reaction. It is obviously higher than the catalytic activity of single hydrogen-type zeolite beta without modification treatment. B. It is less affected by the change of reaction temperature. The catalyst of the present invention has good catalytic activity for synthesizing MTBE at a reaction temperature ranging from 25° C. to 120° C. (see accompanying drawing 1). And strong-acid cation exchange resin has almost no catalytic activity at room temperature, and when the temperature exceeds 90°C, it will cause the obvious loss of active components. For the synthesis of IPE, at 180°C, the catalytic activity of the catalyst of the present invention is equivalent to that _{of AlCl3} , while Am-15 can only react at 80°C, and its activity is far lower than that of the catalyst of the present invention. C. Good selectivity. No by-products are generated in the synthesis of MTBE by using the catalyst of the present invention, but a small amount of by-products will be generated when the strong-acid cation exchange resin has an optimal reaction temperature of 80°C. D. Will not pollute the environment and corrode equipment. In the process of catalytic reaction of strong acid type cation exchange resin, the active component sulfonate will produce acid that pollutes the environment and corrodes equipment due to swelling and loss. AlCl ₃ is also very corrosive to the reaction equipment, and will release acid that pollutes the environment after absorbing water. However, the catalyst of the present invention neither pollutes the environment nor corrodes equipment during use. E. Easy regeneration, good stability. The catalyst of the present invention can be regenerated and used more than 4 times. However, strong acid cation exchange resins and anhydrous AlCl ₃ cannot be regenerated.

The descriptions of the attached drawings are as follows:

为60℃， 为100℃。附图2.显示在反应温度为60℃时，本发明Hβ-γ-Al₂O₃-B₂O₃催化剂与Amberlyst-15催化剂的催化活性比较，图中

为Am-15，

为Hβ-γ-Al₂O₃-B₂O₃。Accompanying drawing 1. shows the catalytic activity of Hβ-γ-Al ₂ O ₃ -B ₂ O ₃ catalysts under different reaction temperatures, among the figure at 40°C,

at 60°C, is 100°C. Accompanying drawing 2. shows that when reaction temperature is 60 ℃, the catalytic activity of Hβ-γ-Al ₂ O ₃ -B ₂ O ₃ catalyst of the present invention is compared with Amberlyst-15 catalyst, among the figure

for Am-15,

It is Hβ-γ-Al ₂ O ₃ -B ₂ O ₃ .

The following experimental examples can further embody the prominent substantive features of the present invention, but are not intended to limit the present invention.

Example 1

Take 20.0 g of sodium zeolite beta, exchange it with 250 ml of 1.0 N NH ₄ Cl solution at 90°C for 4 times, and roast the zeolite obtained during the exchange at 550°C for 4 hours to obtain hydrogen beta zeolite. Get 7.5g hydrogen type beta zeolite and 25.0g solid content be that 10% (percentage by weight) aluminum glue is mixed, then adding concentration is 2% _HNO Solution makes mixed solid wet completely, then adds 0.8g starch, they After mixing evenly, press into strips (2mm in diameter, unlimited length), and dry at 120°C for 4 to 12 hours. Take 10.0 g of the strip-like mixture and impregnate it with a 3.0% boric acid solution prepared from analytically pure boric acid in deionized water, for 12 hours each time, and dry it below 100° C. after each impregnation. A modified hydrogen-type zeolite beta catalyst with a composition of Hβ:γ-Al ₂ O ₃ :B ₂ O ₃ =75:25:6 was thus obtained, which was calcined at 550°C for 4 hours and then stored in a desiccator for use.

Example 2

Get the catalyst 2.0g that makes in embodiment 1, be placed in the tank reactor that volume is 150ml, in reactor, add 17.5ml methyl alcohol, reactor is closed, raise reaction temperature rapidly and reach designated experimental temperature ( 40°C, 60°C, and 100°C respectively), press 38.5ml of isobutylene into the reactor with N ₂ , start timing, and take samples every 5 minutes in the first half hour, and the sampling interval can be longer after half an hour. The sample is analyzed by gas chromatography, and the content of each component in the sample is determined by the internal standard method. The catalytic activity results of Hβ-γ-Al ₂ O ₃ -B ₂ O ₃ catalysts at different reaction temperatures are shown in Figure 1.

Example 3

Get the catalyst 2.0g that makes in the embodiment 1 and Amberlyst-15 resin catalyst 2.0g and be that the reaction of comparative catalytic performance is carried out under the condition of 60 ℃ of reaction temperatures, other reaction conditions are with embodiment 2, and the result is as shown in accompanying drawing 2, It can be seen that the conversion rate of isobutylene of the catalyst of the present invention is equivalent to that of Amber-lyst-15 at 60°C. After the reaction was carried out for 3 hours, 1% of the by-product—isobutylene dimer was produced in the reaction product with Am-berlyst-15 as the catalyst, but no by-product was found in the reaction with the catalyst of the present invention.

Example 4

Reaction temperature is fixed as 60 ℃, and the reaction time is fixed as 3 hours, and other conditions are all identical with embodiment 2, but will carry out 4 times of repeated reaction experiments, after each reaction finishes, catalyzer is regenerated at 550 ℃ of roasting 4 hours, The regenerated catalyst is used for the next reaction, and the results show that the activity and selectivity of the catalyst of the present invention have almost no attenuation, the conversion rate of isobutene is between 80% and 83%, and no by-product is generated.

Example 5

The preparation steps of the catalyst are the same as in Example 1, but the proportions of the components Hβ, γ-Al ₂ O ₃ and B ₂ O ₃ are different, and modified hydrogen-type zeolite beta catalysts with different component ratios are prepared. The reaction conditions were the same as in Example 2 except that the reaction temperature was 60° C. and the reaction time was 3 hours. The properties of the modified hydrogen-type zeolite beta catalysts with different composition ratios for the synthesis of MTBE are listed in Table 1.

Example 6

The catalyst prepared in Example 1 is roasted at different temperatures respectively, and its catalytic performance results are shown in Table 2 (reaction conditions are the same as in Example 5)

Example 7

Get 2.0g of the catalyst prepared in Example 1, put it into a reaction kettle with a volume of 250ml, add 22.0ml of isopropanol, seal the reactor, heat it to 130°C, and press _12.0g of propylene into the In the reaction kettle, the amount of propylene was accurately weighed on a balance with a stainless steel quantitative tube. The reaction temperature was 180° C., the pressure was 5.0 MPa, and the time was 3 hours. The product sample was analyzed by gas chromatography. The conversion rate of propylene was 13.7%. The yield was 29.8%. Its reaction performance is equivalent to the known result of using anhydrous _AlCl3 as a catalyst.

Table 1 The relationship between catalyst composition and performance of the present invention serial number Hβ γ-Al ₂ O ₃ B ₂ O ₃ Isobutene conversion rate (W%) 1 100 0 5 62 2 90 10 1 81 3 75 25 7 82 4 65 35 3 72 5 50 50 5 66 6 65 35 7 74 7 75 25 10 78 8 85 15 20 72 9 90 10 25 64

Table 2 The relationship between the roasting temperature and catalytic performance of catalyst of the present invention serial number Calcination temperature ℃ Conversion rate of isobutene (W%) 1 200 52 2 450 67 3 550 83 4 650 72 5 750 63 6 850 51

Claims (3)

1. A hydrogen-type beta zeolite catalyst for synthesizing methyl tert-butyl ether or isopropyl ether is characterized in that: it is a composite modified hydrogen-type catalyst composed of hydrogen-type beta zeolite, gamma-alumina and boron oxide Beta zeolite catalyst, the weight ratio of its components is, hydrogen type beta zeolite (Hβ): γ-alumina (γ-Al ₂ O ₃ ): boron oxide (B ₂ O ₃ )=50～100:0～50: 0.5～25. 2. The modified hydrogen-type zeolite beta catalyst according to claim 1, characterized in that: the weight ratio of the components of the catalyst is Hβ:γ-Al ₂ O ₃ : _{B 2} O ₃ =70～90:10 ~25:1~7. 3. A method for preparing said catalyst according to claim 1, characterized in that it has included the following three steps: (1) For the preparation of hydrogen-type zeolite beta, a certain amount of sodium-type beta zeolite is exchanged 4 times at 90°C with a sufficient amount of ammonium chloride solution of 1.0 equivalent concentration, and each exchange time is maintained for 2 hours, and the exchange reaction The final zeolite was calcined at 550°C for 4 hours to obtain hydrogen-type zeolite beta; (2) the preparation of hydrogen type beta zeolite and aluminum oxide strip mixture, get the hydrogen type beta zeolite that is 50～100 parts by weight and make in (1) step and solid content is 10% (percentage by weight) 0～ 500 parts by weight of aluminum glue are mixed, adding a concentration of 2% _HNO3 solution until the solid mixture is completely wetted, adding 3% starch with a weight of 3% of the weight of the mixture of hydrogen type zeolite and aluminum glue, mixing them evenly and pressing In strips, dry at 120°C for 4 to 12 hours, the diameter of the strips is 2.0mm, and the length is not limited; (3) impregnating boron oxide, getting a certain gravimetric analysis of pure boric acid to be dissolved in the deionized water of the proportioning amount to make the aqueous solution that the boric acid content is 10.0% (weight), the required amount of hydrogen obtained in (2) step The strip mixture of type β zeolite and alumina is impregnated with boric acid solution diluted from 10.0% concentration to 0.1% ~ 10.0% boric acid solution, each impregnation is 12 hours, after each impregnation, it must be dried below 100°C Re-impregnation, the thus prepared composition is Hβ:γ-Al ₂ O ₃ : _{B 2} O ₃ =50～100:0～50:0.5～25 modified hydrogen type zeolite catalyst and then at 200°C～850°C Lower roasting for 1 to 20 hours.

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