CN112645349A - Preparation method and application of mordenite molecular sieve - Google Patents
Preparation method and application of mordenite molecular sieve Download PDFInfo
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Abstract
The invention discloses a preparation method of a mordenite molecular sieve with a high silica-alumina ratio, which comprises the following three steps: (1) hydroxide containing silicon source I, aluminum source I and alkali metal ions M' and template agent R1Pre-crystallizing the mixture I with water to obtain a silicon-aluminum precursor; (2) hydroxide containing silicon source II, aluminum source II and alkali metal ions M and template agent R2Aging the mixture II with water to obtain structure-oriented sol; (3) and mixing the silicon-aluminum precursor with the structure-oriented sol, performing hydrothermal crystallization, and roasting to obtain the mordenite molecular sieve. The method can be used for preparing the mordenite molecular sieve with the silicon-aluminum ratio higher than 40, and the mordenite molecular sieve can be used for synthesizing acetic acid by carbonylation of dimethyl etherThe catalyst of methyl ester has higher conversion rate of dimethyl ether, and the stability of the catalyst is obviously superior to that of a dimethyl ether carbonylation catalyst prepared by a mordenite molecular sieve synthesized by a one-step method under the same conditions.
Description
Technical Field
The application relates to a preparation method and application of a mordenite molecular sieve, belonging to the technical field of chemical catalysis.
Background
The mordenite molecular sieve is a crystalline microporous aluminosilicate, has a 12-membered ring and 8-membered ring pore channel structure, proper acidity and good hydrothermal stability, becomes an important petroleum refining and petrochemical catalytic material, and has important industrial application value in the fields of catalytic cracking, alkylation, hydroisomerization, dimethyl ether carbonylation and the like. Zeolites having the MOR structure are generally expressed as SiO2/Al2O3The molar ratio of 10-12 is divided into two types, most of the SiO is prepared by most of the prior synthesis techniques without using a template agent2/Al2O3The low-silicon mordenite with the molar ratio of 5-10 is equivalent to the natural mordenite. The high-silicon mordenite can be obtained by dealuminizing treatment methods such as water vapor, acid, complex and the like, and has long and complex operation process; the better method is direct hydrothermal synthesis. It is known that mordenite molecular sieve is a better catalyst carrier for synthesizing methyl acetate by carbonylation of dimethyl ether, and the mordenite molecular sieve with high silica alumina ratio has better acid resistance and stability than the mordenite molecular sieve with lower silica alumina ratio.
UOP corporation has issued patent No. 1 for preparing high-silicon mordenite without adding organic amine, and adopted SiO2/Al2O3The amorphous aluminum silicate gel with the molar ratio of 15-30 is synthesized by adding alkali, but the process for preparing the aluminum silicate gel with high silicon content is complex, the flow is long, and more equipment is needed; itabashi et al reported that SiO can be synthesized from amorphous silica gel2/Al2O3The feeding ratio of the mordenite with the molar ratio of about 15 must be very highThe material cost is economically unreasonable. And preparing the nano-scale mordenite molecular sieve with the silicon-aluminum ratio of 10-30 by using common mordenite molecular sieve powder as a seed crystal and utilizing a sectional crystallization method. In the synthesis process, sodium chloride/sodium sulfate is used as an additive, so that equipment corrosion and environmental pollution are serious, and subsequent application of the molecular sieve is influenced to a certain extent.
Patent reports that a method for synthesizing a high-silicon mordenite molecular sieve by using long-chain biquaternary ammonium salt as a template agent has the advantages that the template agent molecules contain more hydrophilic N-containing groups and O-containing groups or contain pyrrolidinium, and the molecules are relatively complex; there are also patents reporting the synthesis of mordenite molecular sieves with high silica to alumina ratio using pentasil as seed crystal; and the mordenite molecular sieve is synthesized by three-stage crystallization of a halogen compound and an organic template agent.
The results of the research of the literature and Chinese patent show that: the synthesis of mordenite molecular sieve usually uses different silicon source and aluminium source as raw materials, then adds crystal seed or template agent or mineralizer to make silicon-aluminium sol, and makes recrystallization so as to obtain the mordenite molecular sieve.
Disclosure of Invention
According to one aspect of the present application, there is provided a mordenite molecular sieve having a high silica to alumina ratio, which has been prepared by a three-step process and which has a silica to alumina ratio of 40 or even 50 or more. The catalyst is used for synthesizing methyl acetate by carbonylation of dimethyl ether, the conversion rate of the dimethyl ether is higher, and the stability of the catalyst is obviously superior to that of the mordenite molecular sieve with high silica-alumina ratio synthesized by one step under the same conditions. The direct one-step method of mordenite molecular sieve with high silica-alumina ratio can make its silica-alumina ratio less than 40.
According to the method, a three-step method is adopted, firstly, a silicon-aluminum raw material is subjected to pre-crystallization under a hydrothermal condition, and a silicon-aluminum precursor with a structure of kenyaite and mordenite is obtained; preparing silicon-aluminum structure guide sol; finally, the mordenite molecular sieve with the silicon-aluminum ratio higher than 50 can be synthesized after the two are mixed according to a certain proportion and crystallized, and the method is not reported. The precursor with two structures obtained by pre-crystallization has more mesopores and macropores, better thermal stability and acid resistance, and can limit the falling position of aluminum atoms, and the prepared structure-oriented sol is used as a seed crystal, so that more B acid centers can be obtained on 12-membered rings and 8-membered rings in the growth process of the mordenite. The catalyst is used for synthesizing methyl acetate by carbonylation of dimethyl ether, and has better catalytic activity and stability.
According to a first aspect of the present application there is provided a process for the preparation of a mordenite molecular sieve, the process comprising:
(1) hydroxide containing silicon source I, aluminum source I and alkali metal ions M' and template agent R1Pre-crystallizing the mixture I with water to obtain a silicon-aluminum precursor;
in the mixture I, the molar ratio of each substance is as follows:
SiO2：Al2O3＝55～90：1；
M'2O：Al2O3＝1.1～18：1；
R1：Al2O3＝5～10：1；
H2O：SiO2＝5～15：1；
(2) hydroxide containing silicon source II, aluminum source II and alkali metal ions M and template agent R2Aging the mixture II with water to obtain structure-oriented sol;
in the mixture II, the molar ratio of each substance is as follows:
SiO2：Al2O3＝20～50：1；
M2O：Al2O3＝1.0～15：1；
R2：Al2O3＝10～40：1；
H2O：SiO2＝10～25：1；
(3) and mixing the silicon-aluminum precursor with the structure-oriented sol, performing hydrothermal crystallization, and roasting to obtain the mordenite molecular sieve.
Optionally, the silica-alumina precursor is a silica-alumina precursor having the structure of kenyaite and mordenite.
Optionally, the pre-crystallization in step (1) is performed under hydrothermal conditions.
Optionally, the step (3) comprises: mixing the silicon-aluminum precursor and the structure-oriented sol according to a certain proportion, carrying out hydrothermal crystallization, washing, drying and roasting to obtain the mordenite molecular sieve with the high silicon-aluminum ratio.
Optionally, in the step (3), the mass ratio of the silicon-aluminum precursor to the structure-oriented sol is 10-90: 1.
in the application, the mass ratio of the silicon-aluminum precursor solution to the structure-oriented sol is 10-90: 1; if the mass ratio is too high, pure mordenite cannot be obtained; if the mass ratio is too low, mordenite with a higher silica-alumina ratio cannot be obtained.
Optionally, in the step (1), the pre-crystallization conditions are: the temperature is 130-190 ℃; the time is 8-48 hours; the heating rate is 1-5 ℃/min.
Optionally, in the step (2), the aging conditions are: the temperature is 40-90 ℃; the time is 4-24 hours.
In the application, through aging, silicon and aluminum molecules are slowly combined with each other and interact, so that the materials can be mixed more uniformly, and the subsequent growth of the mordenite is facilitated.
Optionally, in the step (3), the hydrothermal crystallization conditions are: the temperature is 150-200 ℃; the time is 18-72 hours;
the roasting conditions are as follows: the temperature is 400-600 ℃; the time is 2-8 hours.
Optionally, in the step (3), the temperature of the hydrothermal crystallization is 160-190 ℃, and the crystallization time is 24-60 hours.
Optionally, in the step (3), the temperature is programmed to the hydrothermal crystallization temperature at a rate of 1-5 ℃/min.
Optionally, in the step (3), the drying temperature is 80-120 ℃, and the drying time is 12-24 hours.
Optionally, the silicon source I and the silicon source II are both independently selected from at least one of silica white, silica sol, sodium silicate and diatomite;
the aluminum source I and the aluminum source II are both independently selected from at least one of sodium aluminate, aluminum isopropoxide, aluminum sulfate and aluminum hydroxide;
the hydroxide of the alkali metal ion M' and the hydroxide of the alkali metal ion M are both independently selected from at least one of lithium hydroxide, sodium hydroxide and potassium hydroxide;
the template agent R1And the template agent R2Each independently selected from at least one of cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetrapropylammonium bromide, tetraethylammonium bromide, tetramethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetrapropylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, hexadecyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethylamine, isopropylamine, diisopropylamine, triisopropylamine, n-butylamine, cyclohexylamine, caprolactam, hexamethyleneimine, heptamethyleneimine, cycloheptaneamine, and cyclopentylamine.
According to a second aspect of the present application there is provided a mordenite molecular sieve selected from at least one of the mordenite molecular sieves prepared according to the above-described process.
Optionally, the mordenite molecular sieve has a silica to alumina ratio of: SiO 22/Al2O3＝40-90。
Optionally, the mordenite molecular sieve has an upper limit value for the silica to alumina ratio selected from 45, 50, 55, 60, 65, 70, 75, 80, 85 or 90; the lower limit is selected from 40, 45, 50, 55, 60, 65, 70, 75, 80 or 85.
According to a third aspect of the application, a catalyst is provided, wherein the catalyst is prepared by sequentially carrying out ammonium ion exchange and roasting on a mordenite molecular sieve;
the mordenite molecular sieve is selected from at least one of the mordenite molecular sieve prepared by the method and the mordenite molecular sieve.
Optionally, the preparation method of the catalyst comprises: and (3) placing the mordenite molecular sieve in a solution containing ammonium salt for ion exchange, and washing, drying and roasting to obtain the catalyst.
According to a fourth aspect of the present application, there is provided a method for preparing the above catalyst, the method comprising: and (3) placing the mordenite molecular sieve in a solution containing ammonium salt, performing ion exchange, and roasting to obtain the catalyst.
Optionally, the ammonium salt is selected from at least one of ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium carbonate.
Optionally, the concentration of ammonium ions in the solution containing ammonium salt is 0.5-2 mol/L.
Alternatively, in the solution containing the ammonium salt, the upper limit of the concentration of the ammonium ion is independently selected from 2mol/L, 1.8mol/L, 1.5mol/L, 1.0mol/L and 0.8mol/L, and the lower limit is independently selected from 0.5mol/L, 1.8mol/L, 1.5mol/L, 1.0mol/L and 0.8 mol/L.
Optionally, the conditions of the ion exchange are: the exchange time is 1-5 hours; the exchange temperature is 50-90 ℃; the liquid-solid mass ratio is 1-8: 1.
alternatively, the upper ion exchange time limit is independently selected from 5 hours, 4 hours, 3 hours, 2 hours and the lower limit is independently selected from 1 hour, 4 hours, 3 hours, 2 hours.
Optionally, the upper temperature limit of the ion exchange is independently selected from 90 ℃, 80 ℃, 70 ℃, 60 ℃ and the lower temperature limit is independently selected from 50 ℃, 80 ℃, 70 ℃, 60 ℃.
Optionally, the upper limit of the liquid-solid mass ratio of the ion exchange is independently selected from 1: 1. 3: 1. 5: 1. 7: 1, the lower limit is independently selected from 8: 1. 3: 1. 5: 1. 7: 1.
optionally, the drying temperature is 100-140 ℃, and the drying time is 8-16 hours.
Optionally, the roasting conditions are: the temperature is 450-600 ℃; the time is 3-6 hours.
According to a fifth aspect of the present application, there is provided a process for the production of methyl acetate, the process comprising: reacting raw material gas containing dimethyl ether and carbon monoxide in the presence of a catalyst to obtain the methyl acetate;
the catalyst is at least one selected from the group consisting of the above-mentioned catalysts and the catalysts prepared according to the above-mentioned methods.
Optionally, the reaction conditions are: the temperature is 180-260 ℃; the pressure is 1-5 MPa; the airspeed of the raw material gas is 1000-10000 h-1。
Alternatively, the upper temperature limit of the reaction is independently selected from 260 ℃, 230 ℃, 200 ℃, and the lower temperature limit is independently selected from 180 ℃, 230 ℃, 200 ℃.
Alternatively, the upper limit of the reaction pressure is independently selected from 5MPa, 4MPa, 3MPa, 2MPa, and the lower limit is independently selected from 1MPa, 2MPa, 3MPa, 4 MPa.
Optionally, the upper space velocity limit of the feed gas is independently selected from 10000h-1、8000h-1、6000h-1、4000h-1、2000h-1The lower limit is independently selected from 1000h-1、8000h-1、6000h-1、4000h-1、2000h-1。
Optionally, the molar ratio of dimethyl ether to carbon monoxide in the feed gas is 1: 1 to 50.
Optionally, the raw material gas also contains an inert gas; the molar ratio of the dimethyl ether to the inert gas is 1: 40-60.
Optionally, the raw material gas also contains an inert gas; the upper limit of the molar ratio of the dimethyl ether to the inert gas is independently selected from 1: 60. 1: 50, the lower limit is independently selected from 1: 40. 1: 50.
optionally, the reaction conditions are: the temperature is 180-220 ℃; the pressure is 1-2 MPa; the feed molar ratio of raw material gas dimethyl ether to carbon monoxide is 1: 1 to 10.
Alternatively, the upper limit of the feed gas dimethyl ether to carbon monoxide molar ratio is independently selected from 1: 1. 1: 2. 1: 3. 1: 4. 1: 5. 1: 6. 1: 7. 1: 8. 1: 9, the lower limit is independently selected from 1: 10. 1: 2. 1: 3. 1: 4. 1: 5. 1: 6. 1: 7. 1: 8. 1: 9.
optionally, the inert gas comprises nitrogen and an inert gas.
Benefits that can be produced by the present application include, but are not limited to:
the mordenite molecular sieve with the silicon-aluminum ratio higher than 40 is prepared by the method, and the used raw materials are common and easy to obtain. Firstly, pre-crystallizing a silicon-aluminum raw material according to a normal feeding mode to obtain a precursor with the structure of kenyaite and mordenite; secondly, preparing structure-oriented sol; and finally, mixing the two components according to a certain proportion, and obtaining the mordenite molecular sieve with the high silica-alumina ratio after crystallization, post-treatment, drying and roasting. The mordenite zeolite molecular sieve has better catalytic activity than mordenite zeolite molecular sieves prepared by other methods when being applied to the reaction of synthesizing methyl acetate by carbonylation of dimethyl ether.
Drawings
Fig. 1 is an XRD spectrum of the silica-alumina precursor of sample 7.
Fig. 2 is an SEM picture of the silicon aluminum precursor of sample 7.
Figure 3 is an XRD spectrum of high silica to alumina ratio mordenite molecular sieve sample 7.
Figure 4 is an SEM picture of high silica to alumina ratio mordenite molecular sieve sample 7.
Figure 5 is an XRD spectrum of a sample of mordenite molecular sieve prepared in comparative example 4.
Fig. 6 shows the stability results of the dimethyl ether carbonylation catalysts prepared in sample 2, sample 3, sample 5 and comparative sample 1.
Detailed Description
The present application will be described in detail with reference to examples, but the present application is not limited to these examples.
The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.
Preparation of mordenite molecular sieve sample with high silica-alumina ratio 1-8
Examples 1 to 8
The method comprises the following steps: mixing sodium hydroxide and an aluminum source (the aluminum source used in the embodiments 1 to 4 is sodium aluminate, and the aluminum source used in the embodiments 5 to 8 is aluminum sulfate) with water, adding 30 wt% of silica sol and cetyl trimethyl ammonium bromide, uniformly stirring, and transferring into a stainless steel high-pressure hydrothermal reaction kettle for pre-crystallization to obtain a silicon-aluminum precursor with the structure of hydroxosillite and mordenite.
Step two: mixing sodium hydroxide, sodium aluminate/aluminum sulfate and water, adding 30 wt% of silica sol and tetraethyl ammonium hydroxide, stirring and aging to obtain the structure-oriented sol.
Step three: mixing the silicon-aluminum precursor obtained in the step one and the structure-oriented sol obtained in the step two according to a certain proportion, uniformly stirring, and transferring the sol mixture into a stainless steel high-pressure hydrothermal reaction kettle for crystallization; and after crystallization, washing the product to be neutral by using deionized water, drying the product for 12 hours at 120 ℃, and roasting the product for 4 hours in a muffle furnace at 550 ℃ to obtain Na-MOR.
Step four: weighing a certain amount of the Na-MOR molecular sieve, placing the Na-MOR molecular sieve in a beaker, and adding 2mol/L of ammonium nitrate solution at the temperature of 80 ℃ in a solid-liquid mass ratio of 1: 8, carrying out ammonium ion exchange for 3 hours, repeating the ammonium ion exchange for 3 times, drying at 120 ℃ for 12 hours, and roasting in a muffle furnace at 550 ℃ for 4 hours to obtain the H-MOR molecular sieve catalyst.
Preparation of comparative sample 1
Comparative example 1
Mixing sodium hydroxide, sodium aluminate and water, adding 30 wt% silica sol, cetyl trimethyl ammonium bromide (CTMAB) and seed crystal (MOR, wherein SiO is2With Al2O3The molar ratio is 30), stirring evenly, transferring the sol into a stainless steel high-pressure hydrothermal reaction kettle for crystallization. After the crystallization is finished, the post-treatment (drying, roasting) and ammonium ion exchange conditions of the product are the same as those of the third step and the fourth step of sample 1.
Preparation of comparative sample 2
Comparative example 2
1.5g of sodium aluminate, 155.6g of 30 wt% silica sol, 1.2g of NaCl, 7.8g of NaOH, 5.5g of cetyltrimethylammonium bromide (CTMAB) and 41g of water are mixed to obtain the silicon-aluminum gel, which comprises the following components: n (SiO)2)/n(Al2O3)＝50.02，n(Na2O)/n(SiO2)＝0.15，n(CTMAB)/n(Al2O3)＝1.65，n(NaCl)/n(SiO2)＝0.03，n(H2O)/n(SiO2) 10; the gel was divided equally into two. Adding 65g deionized water into the first component, diluting, and stirring to obtain diluted gel n (H)2O)/n(SiO2) 20; and transferring the component II to a reaction kettle with a polytetrafluoroethylene lining for pre-crystallization at 110 ℃ for 24 hours, and cooling to obtain pre-crystallization mother liquor.
Slowly adding the diluted component I into the pre-crystallization mother liquor obtained in the step I, uniformly mixing, and then carrying out temperature programming in a reaction kettle at the speed of 1 ℃/min to 170 ℃ for crystallization for 48 hours. After the crystallization is finished, the post-treatment (drying, roasting) and ammonium ion exchange conditions of the product are the same as those of the third step and the fourth step of sample 1.
Preparation of comparative sample 3
Comparative example 3
Commercial Na-MOR, in which SiO is produced by catalyst works from southern Kayaku university2With Al2O3The molar ratio was 20, and the ammonium ion exchange and drying and calcination conditions were the same as in step four of sample 1.
Preparation of comparative sample 4
Comparative example 4
According to the preparation method (CN102718231A) of a layered nano mordenite molecular sieve, 2.698g of hexadecyl trimethyl p-methyl benzene sulfonic acid ammonium salt (CTATos) and 80g of water are mixed with each other, and are heated in a water bath for 2 hours in a constant temperature water bath kettle at the temperature of 60 ℃ to form solution A; mixing 2.107g of sodium hydroxide with 67.8ml of deionized water, stirring to obtain a clear solution, adding aluminum isopropoxide into the clear solution, heating the mixture in a constant-temperature water bath kettle at 60 ℃ for 1 hour, slowly dropwise adding 17.428g of silica sol into the mixture after the aluminum isopropoxide is completely dissolved, then continuously keeping the original constant temperature, and stirring for 2 hours to obtain a solution B; finally, dropwise adding the solution B into the solution A, continuously stirring for 2 hours, transferring the mixture into a stainless steel static crystallization kettle with a polytetrafluoroethylene lining, placing the stainless steel static crystallization kettle into a 130 ℃ oven for crystallization for 5 days, and roasting the mixture for 5 hours at 550 ℃ after conventional suction filtration, deionized water washing and dryingObtaining a solid product. The mixture initially comprises the following components in molar composition: SiO 22：Al2O3＝30，Na2O:SiO2＝0.64，H2O:SiO2102. The post-treatment conditions and process of the product were the same as those of sample 1, step three and step four.
Preparation of comparative sample 5
Comparative example 5
The operation was the same as in example 3, except that the structure-oriented sol was used as it was without aging.
In the preparation process of the samples 1-8, the raw material molar amount, the pre-crystallization temperature and the pre-crystallization time of the silicon-aluminum precursor containing the kenyaite and the mordenite are shown in table 1 in detail.
In the preparation process of samples 1-8, the raw material molar amount, crystallization temperature and time of the structure-oriented sol and comparative sample 1 are detailed in table 2.
The mass ratio of the silicon-aluminum precursor of the samples 1-8 to the structure-oriented sol and the silicon-aluminum molar ratio of the mordenite molecular sieve sample obtained by the final detection of the comparative sample 1 are detailed in table 3.
TABLE 1 preparation conditions of Si-Al precursor of mordenite molecular sieve samples 1-8
TABLE 2 preparation conditions of structure-oriented sols of mordenite molecular sieve samples 1-8 and comparative sample 1
TABLE 3 Mass ratios of Si-Al precursor to structure-oriented sol for each sample and Si-Al molar ratios for the mordenite molecular sieve samples
Example 9
XRD analysis characterization was performed using X' Pert PRO X-ray diffractometer from PANalytical, netherlands, Cu target, ka radiation source (λ ═ 0.15418nm), voltage 40KV, current 40 mA; the instrument used for SEM test is a Hitachi SU8020 field emission scanning electron microscope, and the accelerating voltage is 2 kV. XRD (X-ray diffraction) pattern tests are carried out on samples 1-8 and intermediate product silicon-aluminum ratio precursors when the samples 1-8 are prepared, and by taking a sample 7 as a typical representative, and by taking an XRD pattern of a silicon-aluminum precursor of the sample 7 as a figure 1, the sample has obvious structural characteristics of mordenite, but characteristic peaks of a hydroxosilicate structure (Kenyaite) appear at positions of 4.38 degrees, 8.91 degrees, 25.81 degrees and 27.66 degrees. Fig. 3 is an XRD spectrum of sample 7, which shows that the sample has distinct characteristic peaks of mordenite structure, and has high crystallinity and few impurities. FIG. 5 is an XRD spectrum of comparative sample 4 prepared by the method of the issued patent, which shows that the sample has low crystallinity and high impurity content, but the structure of the ferrihydrite zeolite is not present.
SEM atlas testing was performed on samples 1-8 and the intermediate product silica alumina ratio precursor when samples 1-8 were prepared, taking sample 7 as a representative, and fig. 2 is an SEM picture of the silica alumina precursor of sample 7, it can be seen that this sample clearly has two zeolite structures with different sizes and morphologies, and wherein the specific surface area of the ferrihydrite zeolite is much larger. Fig. 4 is an SEM picture of a mordenite molecular sieve sample 7 with a high silica alumina ratio, and it can be seen that the finally obtained mordenite molecular sieve sample with a high silica alumina ratio has a uniform size and many pores.
Example 10
Product analysis was performed on a FuliGC 9790 gas chromatograph, HP-PLOT/Q column, FID detector; the dimethyl ether (DME) conversion rate and Methyl Acetate (MA) selectivity data are calculated according to an area normalization method.
The above examples and comparative examples were preparedTabletting a prepared mordenite molecular sieve catalyst sample, crushing and screening, weighing 1g of 20-40 mesh catalyst, loading into a fixed bed reactor, and carrying out N reaction at 380 DEG C2In-situ pretreatment is carried out for 3 hours, the temperature is reduced to 190 ℃, the reaction pressure is adjusted to 2.0MPa for activity evaluation, the reaction time is 12 hours in total, and the feeding volume ratio is DME (dimethyl ether): n is a radical of2: 1-CO: 45: 4, the volume space velocity is 1600h-1. The evaluation results of the catalyst for the carbonylation of dimethyl ether to methyl acetate are shown in Table 4.
TABLE 4 results of evaluation of different samples of dimethyl ether carbonylation catalysts
| Name (R) | DME conversion (%) | MA (methyl acetate) Selectivity (%) |
| Sample 1 | 72.5 | 99.7 |
| Sample 2 | 76.4 | 99.8 |
| Sample 3 | 82.9 | 99.9 |
| Sample No. 4 | 82.1 | 99.7 |
| Sample No. 5 | 85.8 | 99.7 |
| Sample No. 6 | 87.3 | 99.5 |
| Sample 7 | 89.4 | 99.4 |
| |
92.8 | 99.6 |
| Comparative sample 1 | 68.8 | 98.4 |
| Comparative sample 2 | 70.6 | 98.7 |
| Comparative sample 3 | 54.3 | 96.5 |
| |
62.6 | 96.7 |
| |
71.7 | 99.2 |
As can be seen from Table 4, the mordenite molecular sieve with high silica alumina ratio synthesized by the three-step method in the application is used as a dimethyl ether carbonylation catalyst, and has better catalytic activity and selectivity compared with the mordenite molecular sieve with the silica alumina ratio of 29.8 directly synthesized by the one-step method under the same conditions. Under the same preparation conditions, the structure-oriented sol is not aged, and the carbonylation activity and selectivity of the prepared mordenite with high silica-alumina ratio are lower than those of a sample prepared after aging. For the mordenite with the high silicon-aluminum ratio, after the mordenite is prepared into the dimethyl ether carbonylation catalyst by ammonium exchange, the lower the silicon-aluminum ratio of the mordenite molecular sieve is within a certain range, the higher the conversion rate of dimethyl ether carbonylation is. Under the evaluation condition, the mordenite molecular sieve with the silicon-aluminum ratio of more than 50 is used as a catalyst for synthesizing methyl acetate by carbonylation of dimethyl ether, and a catalyst with the conversion rate of not less than 72 percent is not reported. In the examples, the conversion of dimethyl ether and the selectivity to methyl acetate were calculated based on the carbon moles of dimethyl ether:
conversion rate of dimethyl ether ═ [ (mole number of dimethyl ether carbon in raw material gas) - (mole number of dimethyl ether carbon in product) ]/(mole number of dimethyl ether carbon in raw material gas) × (100%);
methyl acetate selectivity is (2/3) × (methyl acetate carbon moles in product) ÷ [ (dimethyl ether carbon moles in feed gas) - (dimethyl ether carbon moles in product) ] × (100%).
Examples 11 to 13
Taking sample 8 as an example, the following results, detailed in table 5, were obtained by performing the same procedures as in example 10 while changing the evaluation conditions of the dimethyl ether carbonylation catalyst.
TABLE 5 results of catalyst Performance under various evaluation conditions
Example 14
The samples prepared in the above examples and comparative examples were tabletted, crushed, sieved and weighed1g of 20-40 mesh catalyst is loaded into a fixed bed reactor, and N is carried out at 380 DEG C2In-situ pretreatment is carried out for 3 hours, the temperature is reduced to 220 ℃, the reaction pressure is adjusted to 2.0MPa for activity evaluation, and the feeding volume ratio is DME: n is a radical of2: 1-CO: 45: 5, the volume space velocity is 9600h-1And continuously running for 300 hours. Taking sample 2, sample 3, sample 5 and comparative sample 1 as typical representatives, the stability evaluation results of the catalyst are shown in fig. 5, and it can be seen from the figure that the mordenite molecular sieve with high silica-alumina ratio prepared by the method of the present application is applied to the reaction of synthesizing methyl acetate by carbonylation of dimethyl ether, even if the silica-alumina ratio is more than 60, the initial activity and stability of the mordenite molecular sieve are superior to those prepared by a one-step method.
Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.
Claims (10)
1. A method for preparing a mordenite molecular sieve, said method comprising:
(1) hydroxide containing silicon source I, aluminum source I and alkali metal ions M' and template agent R1Pre-crystallizing the mixture I with water to obtain a silicon-aluminum precursor;
in the mixture I, the molar ratio of each substance is as follows:
SiO2：Al2O3＝55～90：1；
M'2O：Al2O3＝1.1～18：1；
R1：Al2O3＝5～10：1；
H2O：SiO2＝5～15：1；
(2) hydroxide containing silicon source II, aluminum source II and alkali metal ions M and template agent R2And water mixtureII, aging to obtain structure-oriented sol;
in the mixture II, the molar ratio of each substance is as follows:
SiO2：Al2O3＝20～50：1；
M2O：Al2O3＝1.0～15：1；
R2：Al2O3＝10～40：1；
H2O：SiO2＝10～25：1；
(3) mixing the silicon-aluminum precursor and the structure-oriented sol, performing hydrothermal crystallization, and roasting to obtain the mordenite molecular sieve;
in the step (1), the silicon-aluminum precursor is a silicon-aluminum precursor having a structure of kenyaite and mordenite.
2. The preparation method according to claim 1, wherein in the step (3), the mass ratio of the silicon-aluminum precursor to the structure-oriented sol is 10-90: 1;
preferably, in the step (1), the pre-crystallization conditions are: the temperature is 130-190 ℃; the time is 8-48 hours;
preferably, in the step (2), the aging conditions are: the temperature is 40-90 ℃; the time is 4-24 hours;
preferably, in the step (3), the hydrothermal crystallization conditions are: the temperature is 150-200 ℃; the time is 18-72 hours;
the roasting conditions are as follows: the temperature is 400-600 ℃; the time is 2-8 hours;
preferably, the silicon source I and the silicon source II are both independently selected from at least one of white carbon black, silica sol, sodium silicate and diatomite;
the aluminum source I and the aluminum source II are both independently selected from at least one of sodium aluminate, aluminum isopropoxide, aluminum sulfate and aluminum hydroxide;
the hydroxide of the alkali metal ion M' and the hydroxide of the alkali metal ion M are both independently selected from at least one of lithium hydroxide, sodium hydroxide and potassium hydroxide;
the template agent R1And the template agent R2Each independently selected from at least one of cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetrapropylammonium bromide, tetraethylammonium bromide, tetramethylammonium bromide, hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, tetrapropylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, hexadecyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethylamine, isopropylamine, diisopropylamine, triisopropylamine, n-butylamine, cyclohexylamine, caprolactam, hexamethyleneimine, heptamethyleneimine, cycloheptaneamine, and cyclopentylamine.
3. A mordenite molecular sieve selected from at least one of the mordenite molecular sieves prepared by the process of claim 1 or 2.
4. A mordenite molecular sieve as claimed in claim 3, wherein said mordenite molecular sieve has a silica to alumina ratio of: SiO 22/Al2O3＝40～90。
5. The catalyst is characterized in that the catalyst is prepared by sequentially carrying out ammonium ion exchange and roasting on a mordenite molecular sieve;
the mordenite molecular sieve is selected from at least one of the mordenite molecular sieve prepared by the method of claim 1 or 2, the mordenite molecular sieve of claim 3 or 4.
6. A process for preparing the catalyst of claim 5, comprising: and (3) placing the mordenite molecular sieve in a solution containing ammonium salt, performing ion exchange, and roasting to obtain the catalyst.
7. The method according to claim 6, wherein the ammonium salt is at least one selected from the group consisting of ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium acetate, and ammonium carbonate;
preferably, the concentration of ammonium ions in the solution containing ammonium salt is 0.5-2 mol/L;
preferably, the ion exchange conditions are: the exchange time is 1-5 hours; the exchange temperature is 50-90 ℃; the liquid-solid mass ratio is 1-8: 1;
preferably, the roasting conditions are as follows: the temperature is 450-600 ℃; the time is 3-6 hours.
8. A method for producing methyl acetate, comprising: reacting raw material gas containing dimethyl ether and carbon monoxide in the presence of a catalyst to obtain the methyl acetate;
the catalyst is selected from at least one of the catalyst of claim 5, the catalyst prepared by the method of claim 6 or 7.
9. The method according to claim 8, wherein the reaction conditions are as follows: the temperature is 180-260 ℃; the pressure is 1-5 MPa; the airspeed of the raw material gas is 1000-10000 h-1。
10. The production method according to claim 8, wherein the molar ratio of dimethyl ether to carbon monoxide in the feed gas is 1: 1-50;
preferably, the raw material gas also contains an inert gas; the molar ratio of the dimethyl ether to the inert gas is 1: 40-60.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113845128A (en) * | 2021-10-28 | 2021-12-28 | 吉林大学 | MOR zeolite molecular sieve and preparation method thereof |
| CN114213250A (en) * | 2021-12-29 | 2022-03-22 | 延长中科（大连）能源科技股份有限公司 | Method for synthesizing methyl acetate by dimethyl ether carbonylation |
| CN114291823A (en) * | 2021-12-29 | 2022-04-08 | 延长中科（大连）能源科技股份有限公司 | Preparation method of mordenite molecular sieve |
| CN115806300A (en) * | 2021-09-16 | 2023-03-17 | 中国科学院大连化学物理研究所 | Thin-sheet mordenite molecular sieve and preparation method and application thereof |
| CN115818662A (en) * | 2021-09-16 | 2023-03-21 | 中国科学院大连化学物理研究所 | Mordenite molecular sieve, and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106185976A (en) * | 2016-07-22 | 2016-12-07 | 太原理工大学 | A kind of multi-stage porous mordenite molecular sieve and preparation method thereof |
| CN109092348A (en) * | 2017-06-20 | 2018-12-28 | 天津大学 | Mordenite molecular sieve catalyst and preparation method thereof and its application in carbonylation acetic acid methyl esters |
| CN111087002A (en) * | 2019-12-04 | 2020-05-01 | 延长中科（大连）能源科技股份有限公司 | Preparation method and application of mordenite molecular sieve |
| CN111825102A (en) * | 2019-04-18 | 2020-10-27 | 中国科学院大连化学物理研究所 | Dry glue conversion synthesis method of high-silicon Y molecular sieve |
| CN111825103A (en) * | 2019-04-18 | 2020-10-27 | 中国科学院大连化学物理研究所 | Fluorine-containing high-silicon Y molecular sieve and preparation method thereof |
-
2020
- 2020-12-28 CN CN202011581514.2A patent/CN112645349B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106185976A (en) * | 2016-07-22 | 2016-12-07 | 太原理工大学 | A kind of multi-stage porous mordenite molecular sieve and preparation method thereof |
| CN109092348A (en) * | 2017-06-20 | 2018-12-28 | 天津大学 | Mordenite molecular sieve catalyst and preparation method thereof and its application in carbonylation acetic acid methyl esters |
| CN111825102A (en) * | 2019-04-18 | 2020-10-27 | 中国科学院大连化学物理研究所 | Dry glue conversion synthesis method of high-silicon Y molecular sieve |
| CN111825103A (en) * | 2019-04-18 | 2020-10-27 | 中国科学院大连化学物理研究所 | Fluorine-containing high-silicon Y molecular sieve and preparation method thereof |
| CN111087002A (en) * | 2019-12-04 | 2020-05-01 | 延长中科（大连）能源科技股份有限公司 | Preparation method and application of mordenite molecular sieve |
Non-Patent Citations (1)
| Title |
|---|
| 马宇翔;孙娜;王钰佳;杨占旭;王海彦;杨青松;: "导向剂法制备纳米棒状丝光沸石分子筛及其加氢异构化性能" * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115806300A (en) * | 2021-09-16 | 2023-03-17 | 中国科学院大连化学物理研究所 | Thin-sheet mordenite molecular sieve and preparation method and application thereof |
| CN115818662A (en) * | 2021-09-16 | 2023-03-21 | 中国科学院大连化学物理研究所 | Mordenite molecular sieve, and preparation method and application thereof |
| CN115806300B (en) * | 2021-09-16 | 2024-04-12 | 中国科学院大连化学物理研究所 | Thin-sheet mordenite molecular sieve, and preparation method and application thereof |
| CN115818662B (en) * | 2021-09-16 | 2024-04-16 | 中国科学院大连化学物理研究所 | Mordenite molecular sieve, preparation method and application |
| CN113845128A (en) * | 2021-10-28 | 2021-12-28 | 吉林大学 | MOR zeolite molecular sieve and preparation method thereof |
| CN113845128B (en) * | 2021-10-28 | 2023-02-03 | 吉林大学 | MOR zeolite molecular sieve and preparation method thereof |
| CN114213250A (en) * | 2021-12-29 | 2022-03-22 | 延长中科（大连）能源科技股份有限公司 | Method for synthesizing methyl acetate by dimethyl ether carbonylation |
| CN114291823A (en) * | 2021-12-29 | 2022-04-08 | 延长中科（大连）能源科技股份有限公司 | Preparation method of mordenite molecular sieve |
| CN114291823B (en) * | 2021-12-29 | 2023-10-20 | 延长中科（大连）能源科技股份有限公司 | Preparation method of mordenite molecular sieve |
| CN114213250B (en) * | 2021-12-29 | 2024-02-27 | 延长中科（大连）能源科技股份有限公司 | Method for synthesizing methyl acetate by dimethyl ether carbonyl |
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