Method for preparing low-moisture cyclopentyl methyl ether through molecular sieve dehydration
Through the molecular sieve dehydration technology, the 3A molecular sieve was calcined and activated and combined with the negative pressure operation of the distillation tower, the moisture content of cyclopentyl methyl ether was successfully reduced, the problem of high moisture content of cyclopentyl methyl ether was solved, and the preparation of low-water cyclopentyl methyl ether was achieved.
Patent Information
- Application Number
- CN202411644137.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-02-25
AI Technical Summary
The moisture content in cyclopentyl methyl ether products is relatively high and cannot meet certain process requirements, such as additive liquid as electrolyte.
Using molecular sieve dehydration technology, calcined 3A molecular sieve is activated, filled into a fixed bed, and cyclopentyl methyl ether is pumped into the fixed bed through downward inlet and upper outlet, and then sent to a distillation tower for distillation to obtain low-moisture cyclopentyl methyl ether.
It effectively reduces the moisture content of cyclopentyl methyl ether to reach between 50 and 100ppm, meeting the process requirements.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fine chemical industry, in particular to a method for preparing low-water cyclopentyl methyl ether by dehydration of molecular sieve. Background Art
[0002] Cyclopentyl methyl ether is a new type of environmentally friendly high-performance hydrophobic ether solvent, referred to as CPME, which can replace ether solvents such as tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether and dioxane. As a reaction solvent, it can be used for reactions such as Grignard reaction, coupling reaction, coupling amination reaction, metal reduction reaction, Lewis acid reaction and Friedel-Crafts reaction. It is also used in extraction, crystallization, surface treatment and polymerization processes, but the water content is generally above 200ppm, which does not meet the requirements of some processes, such as being used as an additive for electrolytes, etc. Summary of the invention
[0003] The object of the present invention is to provide a method for preparing low-moisture cyclopentyl methyl ether by dehydration of molecular sieves, so as to solve the problem of high moisture content in CPME products.
[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0005] The present invention provides a method for preparing low-moisture cyclopentyl methyl ether by dehydration of molecular sieves, comprising the following steps:
[0006] Calcination activation of 3A molecular sieve to obtain activated 3A molecular sieve;
[0007] The activated 3A molecular sieve is filled into a fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and then sent into a distillation tower for distillation, and low-water cyclopentyl methyl ether is obtained at the top of the tower;
[0008] The cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and the inlet temperature is 30-35° C.;
[0009] The space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 1 to 10 h -1 .
[0010] Preferably, in the above method for preparing low-moisture cyclopentyl methyl ether by dehydrating a molecular sieve, the conditions for calcination activation are: temperature of 200 to 500° C. and time of 2 to 6 hours.
[0011] Preferably, in the above method for preparing low-moisture cyclopentyl methyl ether by dehydrating molecular sieves, the volume of the activated 3A molecular sieve in the fixed bed is 0.5-1L.
[0012] Preferably, in the above-mentioned method for preparing low-moisture cyclopentyl methyl ether by dehydration of molecular sieve, the distillation conditions are: the number of plates is 5 to 10, the feed position is the fourth plate from the bottom to the top, the pressure is -0.08 to -0.06 MPa, the reflux ratio is 0.5 to 1, and the top temperature is 60 to 70°C.
[0013] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:
[0014] In the present invention, the selected molecular sieve has a strong adsorption effect on polar molecules such as water molecules. At the same time, the inlet temperature of the fixed bed should be strictly controlled during the dehydration of the molecular sieve. If the temperature is too high, the water absorption performance will be poor. At the same time, attention should also be paid to the space velocity. If the space velocity is too high, the dehydration effect will be incomplete, and if it is too low, the processing load will be too small. The distillation tower adopts negative pressure operation, which can reduce energy consumption on the one hand, and remove some possible light components on the other hand, improve product quality, and the CPME moisture content obtained can be between 50 and 100 ppm. DETAILED DESCRIPTION
[0015] The present invention provides a method for preparing low-moisture cyclopentyl methyl ether by dehydration of molecular sieves, comprising the following steps:
[0016] Calcination activation of 3A molecular sieve to obtain activated 3A molecular sieve;
[0017] The activated 3A molecular sieve is filled into a fixed bed, and then the cyclopentyl methyl ether is pumped into the fixed bed in a bottom-in and top-out manner, and then sent into a distillation tower for distillation, and low-water cyclopentyl methyl ether is obtained at the top of the tower.
[0018] In the present invention, the conditions for the calcination activation are: the temperature is preferably 200-500°C, more preferably 200-400°C, and more preferably 300°C; the time is preferably 2-6h, more preferably 3-5h, and more preferably 4h.
[0019] In the present invention, the volume of the activated 3A molecular sieve in the fixed bed is preferably 0.5 to 1 L, more preferably 0.6 to 0.9 L, and even more preferably 0.7 to 0.8 L.
[0020] In the present invention, the temperature of the inlet of the fixed bed in which the cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner is preferably 30-35°C, more preferably 31-34°C, and more preferably 32-33°C.
[0021] In the present invention, the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is preferably 1 to 10 h -1 , more preferably 2 to 8 hours -1 , more preferably 4 to 6 hours -1 .
[0022] In the present invention, the distillation conditions are as follows: the number of plates is preferably 5 to 10, more preferably 6 to 9, and more preferably 7 to 8; the feed position is the fourth plate from the bottom to the top; the pressure is preferably -0.08 to -0.06 MPa, more preferably -0.078 to -0.065 MPa, and more preferably -0.075 to -0.07 MPa; the reflux ratio is preferably 0.5 to 1, more preferably 0.6 to 0.9, and more preferably 0.7 to 0.8; the tower top temperature is preferably 60 to 70°C, more preferably 62 to 68°C, and more preferably 65 to 66°C.
[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0024] Example 1
[0025] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0026] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein the diameter of the fixed bed is DN50, the length is 0.8m, and the loading amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 30.5°C, and the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 1H -1 .
[0027] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.001 wt %.
[0028] Example 2
[0029] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0030] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed by the bottom-in and top-out method, and the dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein, the diameter of the fixed bed is DN50, the length is 0.8m, and the filling amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 31°C, and the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 2H -1 .
[0031] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.0088 wt %.
[0032] Example 3
[0033] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0034] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein the diameter of the fixed bed is DN50, the length is 0.8m, and the loading amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 30.8°C, and the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 3H -1 .
[0035] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.0075 wt %.
[0036] Example 4
[0037] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0038] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed by the bottom-in and top-out method, and the dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein, the diameter of the fixed bed is DN50, the length is 0.8m, and the filling amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 31°C, and the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 4h -1 .
[0039] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.0044 wt %.
[0040] Example 5
[0041] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0042] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed by the bottom-in and top-out method, and the dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein, the diameter of the fixed bed is DN50, the length is 0.8m, and the loading amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 30.8℃, and the air velocity of the cyclopentyl methyl ether pumped into the fixed bed is 6H -1 .
[0043] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.0065 wt %.
[0044] Example 6
[0045] The 3A molecular sieve was calcined and activated at 500°C for 3 hours to obtain an activated 3A molecular sieve;
[0046] The activated 3A molecular sieve is filled into the fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and dehydrated cyclopentyl methyl ether is obtained at the outlet of the fixed bed; wherein the diameter of the fixed bed is DN50, the length is 0.8m, and the loading amount of the activated 3A molecular sieve is 1L; the temperature of the inlet of the fixed bed is 31.2°C, and the space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 8h -1 .
[0047] The dehydrated cyclopentyl methyl ether was analyzed by a moisture meter, and the moisture content of the dehydrated cyclopentyl methyl ether was 0.0078 wt %.
[0048] Example 7
[0049] The dehydrated cyclopentyl methyl ether in Example 4 is sent to a distillation tower for distillation to obtain low-moisture cyclopentyl methyl ether at the top of the tower; the number of plates during the distillation process is 10, the feed position is the 4th plate from the bottom to the top of the tower plate, the reflux ratio is 1, the pressure is -0.08 MPa, and the top temperature is 60°C.
[0050] The low-moisture cyclopentyl methyl ether solid was analyzed by chromatography and moisture meter. The content of cyclopentyl methyl ether in the low-moisture cyclopentyl methyl ether was 99.89wt%, and the moisture content was 0.005wt%.
[0051] Example 8
[0052] The dehydrated cyclopentyl methyl ether in Example 4 is sent to a distillation tower for distillation to obtain low-moisture cyclopentyl methyl ether at the top of the tower; the number of plates during the distillation process is 10, the feed position is the 4th plate from the bottom to the top of the tower plate, the reflux ratio is 1, the pressure is -0.08 MPa, and the top temperature is 60°C.
[0053] The low-water cyclopentyl methyl ether solid was analyzed by chromatography and moisture meter. The content of cyclopentyl methyl ether in the low-water cyclopentyl methyl ether was 99.90wt%, and the moisture content was 0.0055wt%.
[0054] Example 9
[0055] The dehydrated cyclopentyl methyl ether in Example 4 is sent to a distillation tower for distillation to obtain low-moisture cyclopentyl methyl ether at the top of the tower; the number of plates during the distillation process is 10, the feed position is the 4th plate from the bottom to the top of the tower plate, the reflux ratio is 1, the pressure is -0.08 MPa, and the top temperature is 60°C.
[0056] The low-water cyclopentyl methyl ether solid was analyzed by chromatography and moisture meter. The content of cyclopentyl methyl ether in the low-water cyclopentyl methyl ether was 99.90wt%, and the moisture content was 0.0048wt%.
[0057] Example 10
[0058] The dehydrated cyclopentyl methyl ether in Example 4 is sent to a distillation tower for distillation to obtain low-moisture cyclopentyl methyl ether at the top of the tower; the number of plates during the distillation process is 10, the feed position is the 4th plate from the bottom to the top of the tower plate, the reflux ratio is 1, the pressure is -0.08 MPa, and the top temperature is 60°C.
[0059] The low-moisture cyclopentyl methyl ether solid was analyzed by chromatography and moisture meter. The content of cyclopentyl methyl ether in the low-moisture cyclopentyl methyl ether was 99.92wt%, and the moisture content was 0.0044wt%.
[0060] Examples 7 to 10 are repeated definitive experiments.
[0061] The reason why the water content of the products in Examples 7 to 10 is higher than that in Example 4 is that the boiling point of water is lower than that of cpme, and it will be preferentially concentrated at the top of the tower during distillation, so the water content will be higher than that in Example 4.
[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing low-moisture cyclopentyl methyl ether by molecular sieve dehydration, characterized in that: The following steps are involved: Calcination activation of 3A molecular sieve to obtain activated 3A molecular sieve; The activated 3A molecular sieve is filled into a fixed bed, and then cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and then sent into a distillation tower for distillation, and low-water cyclopentyl methyl ether is obtained at the top of the tower; The cyclopentyl methyl ether is first pumped into the fixed bed in a bottom-in and top-out manner, and the inlet temperature is 30-35° C.; The space velocity of the cyclopentyl methyl ether pumped into the fixed bed is 1 to 10 h -1 .
2. The method for preparing low-moisture cyclopentyl methyl ether by dehydration of molecular sieve according to claim 1, characterized in that: The conditions for the calcination activation are: temperature of 200-500° C. and time of 2-6 hours.
3. The method for preparing low-moisture cyclopentyl methyl ether by dehydration using molecular sieve according to claim 2, characterized in that: The volume of the activated 3A molecular sieve in the fixed bed is 0.5-1L.
4. The method for preparing low-moisture cyclopentyl methyl ether by dehydration using molecular sieve according to claim 2 or 3, characterized in that: The distillation conditions are as follows: the number of plates is 5 to 10, the feed position is the fourth plate from the bottom to the top, the pressure is -0.08 to -0.06 MPa, the reflux ratio is 0.5 to 1, and the tower top temperature is 60 to 70°C.