CN110156551A - Preparation and Application of Monolithic Catalyst for Cracking Ether Alkanes - Google Patents

Abstract

The present invention develops a monolithic catalyst for cracking ether alkanes to prepare high-purity olefins. The monolithic catalyst is obtained by loading coating slurry and active components on the surface of monolithic honeycomb carrier and calcining at high temperature. The source of the catalyst raw material is Wide range, simple preparation process, low cost, and broad industrial application prospects. Compared with the traditional non-integral catalyst, the monolithic catalyst provided by the present invention has lower bed pressure drop and higher mechanical strength under the premise of ensuring that the conversion rate of raw materials and product selectivity are close to 100%.

Description

Preparation and Application of Monolithic Catalyst for Cracking Ether Alkanes

technical field

The invention relates to the preparation of a monolithic catalyst and its application in the cracking direction of ether alkanes. The invention mainly relates to a method for preparing a monolithic catalyst in which active components and coating slurry are loaded on a honeycomb ceramic carrier, and belongs to the field of preparation of catalytic materials.

Background technique

Since the reform and opening up, the domestic automobile industry has developed rapidly in the fierce market competition, and at the same time, it has driven a rapid increase in gasoline consumption. At the same time, the consumption of oil additives has also increased, especially methyl tertiary butyl ether (MTBE). However, the pollution of water sources by MTBE cannot be ignored. In addition, with the gradual depletion of global oil resources, research and development of new clean energy alternatives to oil has become a new trend, among which new energy vehicles and ethanol gasoline for vehicles are the main solutions to the above challenges. Affected by national policies, my country will promote the use of clean energy ethanol gasoline, the use of gasoline additives such as oxygenated organic compounds will be strictly restricted in the future, and etherified components such as MTBE will no longer be used as gasoline blending components. There are both isobutene and 1-butene in the four carbon components of petroleum cracking. The difference between the boiling points of the two is only 0.6°C. If distillation is used for separation, a large amount of energy will be generated, and high-purity products cannot be obtained. Isobutylene is an important basic chemical raw material, which can be used to produce fine chemicals such as butyl rubber, methyl acrylate and polyisobutylene. There are many synthesis methods of isobutene, and the synthesis-cracking combined process of MTBE provides a new idea for the separation and purification of isobutene in the carbon four components. The process takes MTBE as an intermediate product, firstly prepares MTBE, and then cracks MTBE. This is an ingenious route to prepare high-purity isobutene. The MTBE cracking method can not only alleviate the overcapacity problem of methyl tert-butyl ether, but also improve the utilization efficiency of carbon four components and the economic added value of products, and finally obtain the important chemical product isobutene.

Isopentene is an important fine chemical intermediate raw material, there are three isomers, namely 2-methyl-2-butene (2M2B), 2-methyl-1-butene (2M1B) and 3-methyl-1-butene (3M1B). Isoamylene can be used to produce isoprene, tert-amyl alcohol, pinacolone, essence, fragrance and pesticide, and it is also an intermediate of synthetic rubber, synthetic resin and organic synthesis. In recent years, the domestic use of isopentene has grown rapidly, especially due to the ban on phosphorus-containing pesticides in China, isopentene, which is used as a raw material for the production of triazole fungicides, plant growth regulators and herbicides, and other non-phosphorus pesticides demand has grown rapidly. Catalytic cracking of tert-amyl methyl ether (TAME) is currently the main method for producing isopentene in industry.

The cracking of organic ether compounds containing multiple carbon atoms often produces a series of by-products, so the development of efficient and stable catalysts is particularly critical for the technology of cracking ether-based olefins, and the catalysts used in industry for cracking ether-like alkanes are all non-integral formula catalyst. Due to its special structure, the monolithic catalyst makes the pressure drop of the catalyst bed small, which greatly improves the mass transfer efficiency and is beneficial to the enlargement of the reactor; the monolithic catalyst has high mechanical strength due to its special material composition, and is widely used in industrial It is widely used in production, such as the treatment of harmful exhaust gas from automobiles and the catalytic combustion of VOCs.

Contents of the invention

The technical problem to be solved by the invention is to provide a method for preparing monolithic catalysts. For the first time, monolithic catalysts are used to crack ether alkanes to obtain olefins and alcohols. For example, cracking of ether alkanes such as methyl tert-butyl ether and methyl tert-amyl ether. The monolithic catalyst is composed of a carrier, an active component and a coating slurry, and the main component of the honeycomb carrier is one of cordierite, corundum and mullite. The coating slurry includes a binder and an effective coating component, wherein the binder is one of tetraethyl orthosilicate, methyl methacrylate, aluminum sol, and silica sol, and the effective coating component is molecular sieve ( One of SAPO-34, ZSM-5, TS-1), alumina, silica, the effective coating component accounts for 5%~20% of the mass fraction of the catalyst, the binder and effective coating component The mass ratio is 1:1~10. The active ingredients are magnesium chloride, magnesium sulfate, magnesium nitrate, hydrofluoric acid, sodium fluoride, potassium fluoride, fluorosilicate, ammonium fluorosilicate, ammonium fluoride, fluorosilicate, sulfuric acid, magnesium sulfate, aluminum sulfate, sulfuric acid 1~3 kinds of iron, ammonium sulfate, ammonium bisulfate, phosphoric acid, ammonium phosphate, phosphotungstic acid, and niobic acid, the mass fraction of the active component solution is 0.5%~36%, and the active component accounts for the effective coating component The mass fraction is 0.05%~20%.

The preparation method of the monolithic catalyst in the present invention includes a one-step method and a two-step method.

Wherein the one-step preparation method comprises the following steps.

(1) Prepare slurry. It includes: mixing active components, binders, effective coating components and water, and the mixing method includes emulsification method or ball milling method. The condition of emulsification is that the slurry is emulsified at a speed of 0.1-10 kr/min for 0.5 h and then left to stand for 0-10 hours; the condition of ball milling is that the slurry is ground in a ball mill at 100-800 r/min for 0.5-10 hours.

(2) Coating of slurry. The coating method is direct impregnation or vacuum extraction. The feature of the direct impregnation method is that the honeycomb carrier is immersed in the slurry for 5 minutes, and then dried at 100°C for 2 hours; the feature of the vacuum extraction method is that the vacuum tank is kept in a negative pressure state before coating, and then the The carrier is immersed in the slurry, and finally the vacuum is turned on, and the slurry is pushed into the carrier by atmospheric pressure. After 1-10 minutes, the carrier is taken out and dried at 100°C for 2 hours.

(3) Roasting. The coated carrier is statically roasted in the air at 400-600° C. for 3-6 hours to prepare a monolithic monolithic catalyst for cracking ether alkanes to prepare olefins.

The two-step preparation method comprises the following steps.

(1) Prepare slurry. Including: mixing binder, effective coating components and water. Mixing methods include emulsification or ball milling. The condition of emulsification is that the slurry is emulsified at a speed of 0.1-10 kr/min for 0.5 h and then left to stand for 0-10 hours; the condition of ball milling is that the slurry is ground in a ball mill at 100-800 r/min for 0.5-10 hours.

(2) Coating of slurry. The coating method is direct impregnation or vacuum extraction. The feature of the direct impregnation method is that the honeycomb ceramic carrier is immersed in the slurry for 5 minutes, and then dried at 100°C for 2 hours; the feature of the vacuum extraction method is that the vacuum tank is kept in a negative pressure state before coating, and then Immerse the honeycomb carrier in the slurry, and finally turn on the vacuum, the slurry is pushed into the carrier by atmospheric pressure, take out the carrier after 1-10 minutes, and dry at 100°C for 2 hours.

(3) Roasting. The coated carrier is statically roasted in the air at 300-800° C. for 2-6 hours to prepare a monolithic monolithic catalyst for cracking ether alkanes to prepare olefins.

(4) load active components. Immerse the calcined carrier in (3) in the active component solution for 1-20 hours, take it out and dry it at 100°C for 2 hours.

(5) Roasting. (4) The dried carrier is statically roasted in the air at 300-800°C for 2-6 hours to prepare a monolithic monolithic catalyst for cracking ether organic compounds to prepare olefins.

When the monolithic catalyst involved in the present invention is used for cracking ether to produce olefins, the required reaction temperature is 100-300°C, the liquid flow rate of raw material ether is represented by the liquid volume flowing through the unit volume catalyst per hour, and the liquid space velocity is 0.1-300°C. 15h ^-1 , the reaction pressure is 0.1~1.5MPa. The optimal process conditions are liquid space velocity of 0.5~5h ^-1 , reaction temperature of 150~250℃, and reaction pressure of 0.1~1MPa.

The following implementation examples will further illustrate the present invention, but in no way limit the scope of the present invention.

Detailed ways

Implementation example 1

Mix 5 g of pseudo-boehmite and 45 g of water, add nitric acid dropwise until the pH is 4, and let stand for 2 hours to prepare aluminum sol. Mix 40g of ZSM-5 molecular sieve, 10g of sulfuric acid, 2g of ammonium fluoride, 88g of water with the above-mentioned aluminum sol, emulsify at a speed of 1.5 kr/h for 0.5h and then let it stand for 9 hours to prepare active molecular sieve slurry. The honeycomb cordierite carrier was immersed in the active slurry for 1 minute, then dried at 100°C for 2 hours, and calcined at 400°C for 2 hours. Cut the 2mm*2mm*2mm cube monolithic catalyst to measure the compressive strength to be 380N.

Put 11 ml monolithic catalyst into a miniature fixed-bed reactor with a diameter of 20 mm. The liquid space velocity of methyl tert-amyl ether is 1.5 h ^-1 , the reaction temperature is 150 °C, and the reaction pressure is 0.2 MPa. The conversion of tert-amyl ether was 96%, the selectivity of isoamylene was 99%, and the selectivity of methanol was 97%.

Implementation example 2

Mix 30g of γ-Al ₂ O ₃ , 88g of water and 50g of silica sol with a mass concentration of 30%, and emulsify at a speed of 8.5 kr/h for 0.5 h to prepare alumina slurry. The honeycomb corundum carrier was subjected to vacuum extraction, and the carrier was taken out after 9 minutes, dried at 100°C for 2 hours, and calcined at 700°C for 6 hours. Then the carrier was immersed in a mixed solution of 10g magnesium sulfate, 2g potassium fluoride, 4g ferric sulfate, and 133g water, and allowed to stand for 5 hours, then the carrier was taken out, dried at 100°C for 2 hours, and calcined at 700°C for 3 hours.

11 ml monolithic catalyst was loaded into a micro-fixed-bed reactor with a diameter of 20 mm, the liquid space velocity of methyl tert-butyl ether was 8 h ^-1 , the reaction temperature was 150 °C, and the reaction pressure was 0.6 MPa. The conversion of tert-butyl ether was 95%, the selectivity of isobutene was 97%, and the selectivity of methanol was 96%.

Implementation example 3

Mix 20 g of SAPO-34 molecular sieve, 123 g of water and 15 g of tetraethyl orthosilicate with a mass concentration of 30%, emulsify at a speed of 4.5 kr/h for 0.5 h, and then let stand for 5 hours to prepare a molecular sieve slurry. The honeycomb-shaped mullite carrier was impregnated in the molecular sieve slurry for 5 minutes, dried at 100° C. for 2 hours, and calcined at 400° C. for 2 hours. Then the carrier was immersed in a mixed solution of 10g phosphoric acid, 2g hydrofluoric acid, and 133g water, and allowed to stand for 1 hour, then the carrier was taken out, dried at 100°C for 2 hours, and calcined at 400°C for 4 hours.

Put 11 ml monolithic catalyst into a miniature fixed-bed reactor with a diameter of 20 mm. The liquid space velocity of methyl tert-butyl ether is 2.5 h ^-1 , the reaction temperature is 160 °C, and the reaction pressure is 0.8 MPa. The conversion of tert-butyl ether was 79%, the selectivity of isobutene was 99%, and the selectivity of methanol was 99%.

Implementation example 4

Mix 5 g of pseudo-boehmite and 45 g of water, add nitric acid dropwise until the pH is 4, and let stand for 2 hours to prepare aluminum sol. Mix 50g of TS-1 molecular sieve, 88g of water, 10g of ammonium bisulfate, 2g of hydrofluoric acid and the above-mentioned aluminum sol, grind the slurry in a ball mill for 7 hours, and then let it stand for 1 hour to obtain a molecular sieve slurry. The honeycomb cordierite carrier was impregnated in the molecular sieve slurry for 5 minutes, dried at 100°C for 2 hours, and calcined at 400°C for 2 hours. Then impregnate the carrier in a mixed solution consisting of 10g sodium fluoride, 2g magnesium nitrate and 133g water, let it stand for 1 hour, take out the carrier, dry at 100°C for 2 hours, and bake at 400°C for 4 hours.

11 ml monolithic catalyst was loaded into a micro-fixed-bed reactor with a diameter of 20 mm, the liquid space velocity of methyl tert-amyl ether was 2.5 h ^-1 , the reaction temperature was 150 °C, and the reaction pressure was 0.3 MPa. The conversion of tert-amyl ether was 96%, the selectivity of isoamylene was 95%, and the selectivity of methanol was 96%.

Implementation Example 5

Mix 5 g of pseudo-boehmite and 45 g of water, add nitric acid dropwise until the pH is 4, and let stand for 2 hours to prepare aluminum sol. Mix 40g of γ-Al ₂ O ₃ , 88g of water, 10g of ammonium bisulfate, 2g of fluorosilicic acid, 3g of ammonium phosphate and the above aluminum sol, grind the slurry in a ball mill for 1 hour, and after standing for 5 hours, the alumina slurry is obtained material. The honeycomb corundum carrier was subjected to vacuum extraction, and the carrier was taken out after 9 minutes, dried at 100°C for 2 hours, and calcined at 700°C for 6 hours.

11 ml monolithic catalyst was loaded into a micro-fixed bed reactor with a diameter of 20 mm, the liquid space velocity of methyl tert-butyl ether was 3 h ^-1 , the reaction temperature was 140 °C, and the reaction pressure was 0.5 MPa. The conversion of tert-butyl ether was 92%, the selectivity of isobutene was 95%, and the selectivity of methanol was 97%.

Implementation Example 6

Mix 40g of ZSM-5 molecular sieve, 10g of fluosilicic acid, 2g of ammonium bisulfate, 88g of water and 15g of methyl methacrylate with a mass concentration of 30%, emulsify for 0.5 h at a speed of 1.5 kr/h, and then let stand for 9 hours , to prepare active molecular sieve slurry. The honeycomb cordierite carrier was subjected to vacuum extraction, and the carrier was taken out after 9 minutes, dried at 100° C. for 2 hours, and calcined at 700° C. for 6 hours.

Put 11 ml monolithic catalyst into a miniature fixed-bed reactor with a diameter of 20 mm. The liquid space velocity of methyl tert-amyl ether is 1.5 h ^-1 , the reaction temperature is 150 °C, and the reaction pressure is 0.2 MPa. The conversion of tert-amyl ether was 88%, the selectivity of isoamylene was 96%, and the selectivity of methanol was 96%.

Implementation example 7

Mix 40g of ZSM-5 molecular sieve, 10g of ammonium phosphate, 2g of phosphotungstic acid, 88g of water and 15g of methyl methacrylate with a mass concentration of 30%, emulsify at a speed of 1.5 kr/h for 0.5 h and then let it stand for 6 hours. Prepare active molecular sieve slurry. The honeycomb cordierite carrier was immersed in the active slurry for 1 minute, dried at 100°C for 2 hours, and calcined at 400°C for 2 hours.

Put 11 ml monolithic catalyst into a miniature fixed-bed reactor with a diameter of 20 mm. The liquid space velocity of methyl tert-amyl ether is 2 h ^-1 , the reaction temperature is 150 °C, and the reaction pressure is 0.4 MPa. The conversion of tert-amyl ether was 90%, the selectivity of isoamylene was 95%, and the selectivity of methanol was 96%.

Claims (5)

1. a kind of integral catalyzer for preparing alkene for cracking ethers alkane, it is characterised in that the integral catalyzer is by applying Layer slurry and active component are loaded on honeycomb support and are obtained through high-temperature roasting.

2. the integral catalyzer is made of carrier, active component and coating paste；Honeycomb support described in claim 1 Main component is one of cordierite, corundum and mullite；Active component described in claim 1 is magnesium chloride, sulphur Sour magnesium, magnesium nitrate, hydrofluoric acid, sodium fluoride, potassium fluoride, fluosilicic acid, ammonium fluosilicate, ammonium fluoride, fluosilicic acid, sulfuric acid, magnesium sulfate, sulphur Sour aluminium, ferric sulfate, ammonium sulfate, ammonium hydrogen sulfate, phosphoric acid, ammonium phosphate, phosphotungstic acid, 1 ~ 3 kind in niobic acid, the matter of active component solution Measuring score is 0.5% ~ 36%, and the mass fraction that active component occupies effect coating ingredients is 0.05% ~ 20%.

3. coating paste described in claim 1 includes binder and effective coating ingredients, wherein binder be ethyl orthosilicate, One of methyl methacrylate, Aluminum sol, silica solution, effective coating ingredients are molecular sieve (SAPO-34, ZSM-5, TS- 1), one of aluminium oxide, silica, effective coating ingredients account for catalyst mass fraction be 5% ~ 20%, binder and effectively The mass ratio of coating ingredients is 1:1 ~ 10.

4. method for preparing catalyst described in claim 1 includes two kinds of preparation methods of one-step method and two-step method；

(A) one-step preppn process the following steps are included:

(1) prepare slurry: including mixing active component, binder, effective coating ingredients and water, mixed method includes emulsification Method or ball-milling method, the condition of emulsification are to stand 0 ~ 10 hour after slurry emulsifies 0.5 h with the revolving speed of 0.1 ~ 10 kr/min；Ball milling Condition be slurry in the ball mill with 100 ~ 800 r/min mill 0.5 ~ 10 hour；

(2) coating of slurry;The method of coating is direct dipping process or vacuum extraction method；Direct dipping process is characterized in that: will Honeycomb support, which is impregnated in slurry, to be kept for 5 minutes, then 2 hours dry at 100 DEG C；Vacuum extraction method is characterized in that: being applied Vacuum tank is first kept into negative pressure state before covering, then by carrier impregnation in slurry, finally opens vacuum, slurry is pushed away by atmospheric pressure Enter carrier inside, 1 ~ carrier is taken out after ten minutes, it is 2 hours dry at 100 DEG C；

(3) roast: the carrier after coating stands roasting 3 ~ 6 hours in 400 ~ 600 DEG C of air, is made for cracking ethers alkane Hydrocarbon prepares the integral catalyzer of alkene；

(B) two-step preparation method comprises the steps of:

(1) it prepares slurry: binder, effective coating ingredients and water is mixed；Mixed method includes emulsion process or ball-milling method；Cream The condition of change is to stand 0 ~ 10 hour after slurry emulsifies 0.5 h with the revolving speed of 0.1 ~ 10 kr/min；The condition of ball milling is that slurry exists With 100 ~ 800 r/min mill 0.5 ~ 10 hour in ball mill；

(2) coating of slurry: the method for coating is direct dipping process or vacuum extraction method；Direct dipping process is characterized in that: will Cellular structure ceramic carrier, which is impregnated in slurry, to be kept for 5 minutes, then 2 hours dry at 100 DEG C；The feature of vacuum extraction method exists In: vacuum tank is first kept into negative pressure state before coating, then honeycomb support is impregnated in slurry, finally opens vacuum, is starched Expect to be pushed into carrier inside by atmospheric pressure, 1 ~ carrier is taken out after ten minutes, it is 2 hours dry at 100 DEG C；

(3) roast: the carrier after coating stands roasting 2 ~ 6 hours in 300 ~ 800 DEG C of air, is made for cracking ethers alkane Hydrocarbon prepares the monoblock type integral catalyzer of alkene；

(4) load active component；Baked carrier is impregnated to 1 ~ 20 hour in active component solution, 100 after taking-up DEG C dry 2 hours；

(5) it roasts: the carrier after drying being stood to roasting 2 ~ 6 hours in 300 ~ 800 DEG C of air, is made for cracking ethers Organic compound prepares the monoblock type integral catalyzer of alkene.

5. the cracking technology of the integral catalyzer in claim 1 are as follows: the liquid air speed of ethers alkane is 0.1 ~ 15h^-1, reaction Temperature is 100 ~ 300 DEG C, and reaction pressure is 0.1 ~ 1.5MPa；Optimised process is that liquid air speed is 0.5 ~ 5h^-1, reaction temperature is 150 ~ 250 DEG C, reaction pressure is 0.1 ~ 1MPa.