阅读说明：本技术 一种利用多级孔硅分子筛气相吸附分离高沸点同分异构体的方法 (Method for separating high-boiling-point isomer by utilizing gas phase adsorption of hierarchical pore silicon molecular sieve ) 是由 刘定华 张圣洁 朱志敏 亓士超 刘晓勤 孙林兵 谈朋 刘国良 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种利用多级孔全硅分子筛气相吸附分离高沸点同分异构体混合物的方法,该方法通过条状多级孔全硅分子筛吸附剂孔径大小与分子直径之间的关系择形吸附分离同分异构体。该方法包括以下步骤：将高沸点同分异构体混合物从装有多级孔全硅分子筛的吸附柱上方流入,形成混合气体；混合气体通过保温箱进入到吸附柱中,分子直径小于分子筛孔径的化合物被吸附,分子直径与分子筛孔径相差较大的化合物不被吸附并从吸附柱下方流出,收集得到目标产品；得到目标产品后,再用去离子水流入脱附预热端,汽化形成水蒸气,通过水蒸气将多级孔全硅分子筛中吸附的化合物吹扫出来冷凝后形成液体,多级孔全硅分子筛实现再生,吸附柱进入循环使用。(The invention discloses a method for separating a high-boiling-point isomer mixture by utilizing a hierarchical pore all-silicon molecular sieve through gas phase adsorption. The method comprises the following steps: enabling the high-boiling-point isomer mixture to flow into an adsorption column filled with a hierarchical pore all-silicon molecular sieve to form mixed gas; the mixed gas enters an adsorption column through a heat insulation box, a compound with the molecular diameter smaller than the aperture of the molecular sieve is adsorbed, a compound with the molecular diameter greatly different from the aperture of the molecular sieve is not adsorbed and flows out from the lower part of the adsorption column, and a target product is obtained by collection; and after a target product is obtained, the target product flows into the desorption preheating end by using deionized water, the deionized water is vaporized to form water vapor, the compound adsorbed in the hierarchical pore all-silicon molecular sieve is swept out by the water vapor and condensed to form liquid, the hierarchical pore all-silicon molecular sieve is regenerated, and the adsorption column is recycled.)

1. A method for separating a high-boiling-point isomer mixture by gas phase adsorption of a hierarchical pore all-silicon molecular sieve is characterized by comprising the following steps:

a vaporization stage: enabling the high-boiling-point isomer mixture to flow into the adsorption column filled with the hierarchical pore all-silicon molecular sieve, enabling the temperature of the adsorption preheating end to reach the boiling point of the mixture, and enabling the isomers in the mixture to be vaporized to form mixed gas;

an adsorption stage: the mixed gas enters an adsorption column through a heat insulation box, a compound with the molecular diameter smaller than the aperture of the molecular sieve is adsorbed, a compound with the molecular diameter greatly different from the aperture of the molecular sieve is not adsorbed and flows out from the lower part of the adsorption column, and a target product is obtained after the compound is condensed into liquid;

a desorption stage: and after a target product is obtained, the target product flows into the desorption preheating end by using deionized water, the deionized water is vaporized to form water vapor, the compound adsorbed in the hierarchical pore all-silicon molecular sieve is swept out by the water vapor and condensed to form liquid, the hierarchical pore all-silicon molecular sieve is regenerated, and the adsorption column is recycled.

2. The process of claim 1, wherein the high boiling isomer mixture has a boiling point of more than 200 ℃ and is separated by gas phase adsorption using a multiwell all-silica molecular sieve.

3. The method of claim 2, wherein the mixture of high boiling isomers is a chloro-o-nitrotoluene isomer mixture or a dichlorotoluene isomer mixture.

4. The method of claim 3, wherein the chloro-o-nitrotoluene isomer mixture is a mixture of 6-chloro-2-nitrotoluene and 2-nitro-4-chlorotoluene, and the dichlorotoluene isomer mixture is a mixture of 2, 4-dichlorotoluene, 2, 5-dichlorotoluene and 2, 6-dichlorotoluene.

5. The method of claim 1, wherein the method for the vapor phase adsorptive separation of a mixture of high boiling isomers using a hierarchical pore all-silica molecular sieve comprises the steps of:

mixing the raw powder of the all-silicon molecular sieve, the silica gel binder and the attapulgite by the weight ratio of 10: 0.5-5: 0.5-5, uniformly mixing, putting into a die, keeping under the pressure of 5-7 MPa for more than 1min, crushing the pressed adsorbent, adding water accounting for 10-15% of the total weight of the solid raw materials into the crushed raw materials, uniformly mixing, and extruding into strips to obtain stripsThe formed molecular sieve adsorbent is polished, dehumidified and activated, and the molecular sieve is dehydrated at high temperature to obtain the hierarchical pore all-silicon molecular sieve.

6. The method of claim 5, wherein the multi-stage pore all-silica molecular sieve is a strip multi-stage pore all-silica molecular sieve, and has micropores and mesopores, the pore size of the micropores is concentrated at 1 ± 0.5nm, the pore size of the mesopores is concentrated at 5.5 ± 2.5nm, the bulk density is 0.65 ± 0.5g/mL, and the specific surface area is greater than 300m²The water content is lower than 1.5 percent per gram.

7. The method for separating the mixture of high-boiling-point isomers by gas-phase adsorption of the hierarchical porous all-silicon molecular sieve according to claim 1, wherein the vaporization, the adsorption and the desorption are carried out under a gas-phase condition, and the temperature of an incubator is 220-280 ℃; when the raw materials passing through the adsorption stage are heated, the temperature of a heating furnace at the preheating end is 200-270 ℃, the temperature of an adsorption column is 200-280 ℃, the sampling speed of the raw materials is 20-50 mL/h, and the adsorption airspeed of the raw materials is 0.03-0.15 h^-1(ii) a When the deionized water passes through the heating device in the desorption stage, the temperature of the preheating end is 220-280 ℃, the temperature of the adsorption column is 200-300 ℃, and the desorption airspeed of the deionized water is 0.15-0.3 h^-1。

8. The method for separating the mixture of high-boiling-point isomers by gas-phase adsorption of the hierarchical porous all-silicon molecular sieve according to claim 7, wherein the temperature of the heat preservation box is 230-260 ℃; the temperature of the preheating end heating furnace is set to be 230-260 ℃; the setting temperature of an adsorption column in the adsorption stage is 250-270 ℃; the set temperature of the adsorption column in the desorption stage is 220-260 ℃.

9. The method of claim 1, wherein the speed of deionized water entering the desorption preheating end through a pump is 1-3 mL/min, and the desorption time of deionized water passing through the adsorption column is 120-300 min.

Technical Field

The invention relates to a method for separating an isomer mixture by gas phase adsorption, in particular to a method for separating a high-boiling-point isomer mixture by gas phase adsorption by using a hierarchical pore all-silicon molecular sieve.

Background

In organic chemistry, compounds of the same molecular formula but different structures are referred to as isomers, and due to the close boiling points of the isomers, the mixture is difficult to separate. The traditional method adopts the processes of rectification-crystallization-re-rectification-recrystallization and the like, and adopts the traditional rectification tower method to separate the isomer mixture, although the required product can be directly obtained, the rectification tower has a complex structure and large energy consumption, the high-purity product is difficult to obtain, and the combined processes of rectification-crystallization-re-rectification-recrystallization and the like are required in the industrial production process, so that the production cost is higher and the production efficiency is lower.

For separating isomer mixtures with similar boiling points, a proper molecular sieve can be selected for selective adsorption directly according to the difference of the size and polarity of molecules of the isomer mixtures. The molecular sieve has regular and uniform intra-crystalline pore channels, and can realize the purpose of separating isomer mixtures by utilizing the characteristic that the pore size is close to the molecular size and adopting shape-selective adsorption according to different molecular geometric sizes.

For example: the 2, 6-dichlorobenzaldehyde is an important intermediate in the synthesis process of benzoylurea insecticides, is used for synthesizing the next intermediate 2, 6-dichlorobenzaldehyde oxime, and finally obtains pesticide varieties such as hexaflumuron, diflubenzuron and the like. For synthetic dyes, also as fungicides and for the production of the herbicide 2, 6-dichlorobenzonitrile; used for producing acid mordant blanched B; can also be used for preparing diclofenac sodium in the pharmaceutical industry. The prior industrial technology is the production by hydrolysis of 2, 6-dichlorobenzylidene chloride, and the following two methods can be used for obtaining the 2, 6-dichlorobenzylidene chloride according to different raw material sources.

Firstly, using o-nitrotoluene as a raw material, chloridizing to obtain a mixture of 6-chloro-2-nitrotoluene and 4-chloro-2-nitrotoluene, separating to obtain 6-chloro-2-nitrotoluene, chloridizing to obtain 2, 6-dichlorobenzylidene dichloride, and finally hydrolyzing to obtain 2, 6-dichlorobenzaldehyde. The crude products obtained after the chlorination reaction of the o-nitrotoluene mainly comprise o-nitrotoluene, 6-chloro-2-nitrotoluene, 4-chloro-2-nitrotoluene and polychlorinated nitrotoluene. At present, in industrial production, o-nitrotoluene and polychlorinated nitrotoluene in a crude product are removed by rectification, the boiling point difference between the residual 6-chloro-2-nitrotoluene and 4-chloro-2-nitrotoluene is small, and the high-purity 6-chloro-2-nitrotoluene is difficult to obtain, so that the method needs to be realized by a crystallization-rectification-crystallization combination mode for many times, has high separation cost and low yield, and becomes a key step for hindering the development of 2, 6-dichlorobenzaldehyde. In the prior art, a rectification experiment is carried out in the separation research of a 6-chloro-2-nitrotoluene mixture, a rectification column adopts a glass column with phi 26mm, high-efficiency stainless steel triangular wire packing is filled in the rectification column, the height of the packing is 900mm, the number of theoretical plates is 27, and a 6-chloro-2-nitrotoluene target product with the purity of more than 96 percent can be obtained through double-tower runoff. Considering industrial application, the separation is feasible by adopting a double-tower rectification mode, because the boiling points of all components in the mixture are above 220 ℃ under normal pressure, if the existing heating source of a manufacturer is considered and the energy-saving aspect is considered, only a reduced pressure rectification mode can be adopted. From the practical production, although the investment can be saved by intermittent rectification, the treatment capacity is small, the yield is low, and the industrial requirement is difficult to achieve; although the yield of the continuous rectification is not a problem, two higher rectification towers are needed, the investment is large, and the old equipment cannot be utilized.

And (2) continuously chlorinating o-chlorotoluene to obtain a dichlorotoluene mixture of 2, 6-dichlorotoluene, separating to obtain 2, 6-dichlorotoluene, chlorinating again to obtain 2, 6-dichlorobenzylidene dichloride, and finally hydrolyzing to obtain 2, 6-dichlorobenzaldehyde. The crude product obtained after the chlorination reaction of the o-chlorotoluene mainly contains the o-chlorotoluene, 2, 3-dichlorotoluene, 2, 4-dichlorotoluene, 2, 5-dichlorotoluene and 2, 6-dichlorotoluene; the boiling point difference between isomers in the same system is small, and the separation process becomes a key step for obtaining 2, 6-dichlorotoluene and 2, 6-dichlorobenzaldehyde. Chinese patent publication No. CN102311306A discloses a method of rectifying-crystallizing-recrystallizing mixture of dichlorotoluene isomers to obtain filtrate, removing 2, 3-dichlorotoluene during the rectification, mixing the crystals obtained from the first crystallization and the filtrate obtained from the recrystallization, separating, obtaining 2, 6-dichlorotoluene from the extract, and obtaining 2, 5-dichlorotoluene from the raffinate. Chinese patent publication No. CN1315217A discloses a method for separating mixed dichlorobenzene by hydrophobic silicalite liquid phase selective adsorption. Under the condition of liquid phase, an MFI type hydrophobic silicalite molecular sieve adsorbent is adopted to adsorb and separate at least two dichlorobenzene isomer mixtures, the adsorbent preferentially and selectively adsorbs p-dichlorobenzene and (or) o-dichlorobenzene, and the unadsorbed component m-dichlorobenzene can be directly recovered from the raffinate, so that the high-purity m-dichlorobenzene can be obtained. Chinese patent publication No. CN1338328A discloses a method for separating mixed dichlorobenzene by gas phase selective adsorption, which comprises passing mixed dichlorobenzene through zeolite molecular sieve adsorbent in gas phase state, selectively adsorbing p-dichlorobenzene by adsorbent, and rectifying the residue by conventional rectification method to obtain m-dichlorobenzene with purity of more than 99.7%. Chinese patent publication No. CN1136549A discloses a method for separating meta-xylene and ortho-xylene from mixed xylene and ethylbenzene. The mixed solution passes through an adsorption bed filled with a binderless MFI type zeolite molecular sieve adsorbent in a gas phase state, the adsorbent selectively adsorbs ethylbenzene and paraxylene, and the adsorption residues are m-xylene and o-xylene. The residue is rectified by conventional method to obtain meta-xylene and ortho-xylene with purity higher than 99.5%. Chinese patent publication No. CN1613783A discloses a method for separating nitrotoluene wastewater by zeolite adsorption and resource recovery, which uses the selective adsorption of HZSM-5 zeolite to statically adsorb and treat organic wastewater containing nitrotoluene isomers, wherein the ratio of the initial concentration of o-nitrotoluene to the initial concentration of p-nitrotoluene is 1: when the reaction time is 1, the adsorption is carried out for 20min, and the separation rate of the p-nitrotoluene is up to more than 98.8 percent. Chinese patent publication No. CN102311306a discloses a method for adsorptive separation of dichlorotoluene isomers, in which filtrate obtained by the first crystallization is recrystallized to obtain high-purity 2, 4-dichlorotoluene, the filtrate is subjected to adsorptive separation by means of AgNaX zeolite adsorbent to obtain 98.2% purity 2, 6-dichlorotoluene from the extract, and 2, 5-dichlorotoluene from the raffinate.

In conclusion, the molecular sieve adsorption separation method is adopted for separating isomer mixtures with similar boiling points, so that the process is simplified, the product purity is improved, the pollution is reduced, the energy consumption is low, and the method is a feasible process route. With the continuous expansion and development of more molecular sieve types and varieties and the increase of the widening and demand of the application field, the adsorption and separation of the molecular sieve on isomers are necessarily paid more attention, and the molecular sieve has better development prospect. However, the research on isomers such as chloro-o-nitrotoluene and dichlorotoluene with relatively high boiling point (more than 200 ℃) is relatively less so far, the requirement that high-purity raw materials for producing 2, 6-dichlorobenzaldehyde need to be further opened is met, besides the selection of a molecular sieve with rich pore size distribution, proper pore size and proper price, the complex preparation and powder forming of the adsorbent also hinder the further application of the adsorbent.

Disclosure of Invention

The invention provides a method for separating a high-boiling-point isomer mixture by utilizing a hierarchical pore all-silicon molecular sieve through gas phase adsorption, aiming at the problems and the defects of the prior art, the method selects low-price hierarchical pore all-silicon molecular sieve raw powder and a proper binder to shape into a strip-shaped hierarchical pore all-silicon molecular sieve, and the molecular sieve framework has better hydrophobicity and lipophilicity, adsorption separation characteristics and thermal stability due to the deletion of aluminum atoms. Taking chloro-o-nitrotoluene and dichlorotoluene isomers with high boiling point (more than 200 ℃) as an example, the molecular diameter of 2-nitro (chloro) -4(5) -chlorotoluene is slightly smaller than that of 2-nitro (chloro) -6-chlorotoluene, and a proper strip-shaped multi-level pore all-silicon molecular sieve is obtained by a specific forming method, so that the theoretical shape-selective pore diameter can adsorb 2-nitro-4-chlorotoluene in the chloro-o-nitrotoluene isomer mixture to obtain high-purity 2-nitro-6-chlorotoluene, and adsorb 2, 4-dichlorotoluene, 2, 5-dichlorotoluene and the like in the dichlorotoluene isomer mixture to obtain high-purity 2, 6-dichlorotoluene.

The invention is realized by the following technical scheme:

the invention relates to a method for separating a high-boiling-point isomer mixture by utilizing gas phase adsorption of a hierarchical pore all-silicon molecular sieve, which comprises the following steps:

a vaporization stage: enabling the high-boiling-point isomer mixture to flow into the adsorption column filled with the hierarchical pore all-silicon molecular sieve, enabling the temperature of the adsorption preheating end to reach the boiling point of the mixture, and enabling the isomers in the mixture to be vaporized to form mixed gas;

an adsorption stage: the mixed gas enters an adsorption column through a heat insulation box, a compound with the molecular diameter smaller than the aperture of the molecular sieve is adsorbed, a compound with the molecular diameter greatly different from the aperture of the molecular sieve is not adsorbed and flows out from the lower part of the adsorption column, and a target product is obtained after the compound is condensed into liquid;

a desorption stage: and after a target product is obtained, the target product flows into the desorption preheating end by using deionized water, the deionized water is vaporized to form water vapor, the compound adsorbed in the hierarchical pore all-silicon molecular sieve is swept out by the water vapor and condensed to form liquid, the hierarchical pore all-silicon molecular sieve is regenerated, and the adsorption column is recycled.

The method for separating the high-boiling-point isomer mixture by utilizing the gas phase adsorption of the hierarchical pore all-silicon molecular sieve further adopts the technical scheme that the boiling point of the high-boiling-point isomer mixture exceeds 200 ℃. The further technical proposal is that the high boiling point isomer mixture is chloro-o-nitrotoluene isomer mixture or dichlorotoluene isomer mixture. The further technical proposal is that the chloro-o-nitrotoluene isomer mixture is a mixture of 6-chloro-2-nitrotoluene and 2-nitro-4-chlorotoluene, and the dichlorotoluene isomer mixture is a mixture of 2, 4-dichlorotoluene, 2, 5-dichlorotoluene and 2, 6-dichlorotoluene. The chloro-o-nitrotoluene mixture is obtained by catalytic chlorination of o-nitrotoluene, and generally comprises 6-chloro-2-nitrotoluene (with the content of about 60-75%) and 2-nitro-4-chlorotoluene (with the content of about 25-40%); the dichlorotoluene mixture is obtained by continuous chlorination of toluene, and generally comprises 2, 4-dichlorotoluene (30-40%), 2, 5-dichlorotoluene (30-40%) and 2, 6-dichlorotoluene (20-30%).

The invention further discloses a technical scheme of the method for separating the high-boiling-point isomer mixture by utilizing the gas phase adsorption of the hierarchical pore all-silicon molecular sieve, wherein the preparation method of the hierarchical pore all-silicon molecular sieve comprises the following steps:

mixing the raw powder of the all-silicon molecular sieve, the silica gel binder and the attapulgite by the weight ratio of 10: 0.5-5: 0.5-5, uniformly mixing, putting into a die, keeping under the pressure of 5-7 MPa for more than 1min, crushing the pressed adsorbent, adding water accounting for 10-15% of the total weight of the solid raw materials into the crushed raw materials, uniformly mixing, and extruding into strips to obtain stripsThe formed molecular sieve adsorbent is polished, dehumidified and activated, and the molecular sieve is dehydrated at high temperature to obtain the hierarchical pore all-silicon molecular sieve. The technical scheme is that the hierarchical pore all-silicon molecular sieve is a strip hierarchical pore all-silicon molecular sieve, micropores and mesopores exist simultaneously, the pore size of the micropores is concentrated at 1 +/-0.5 nm, the pore size of the mesopores is concentrated at 5.5 +/-2.5 nm, the bulk density is 0.65 +/-0.5 g/mL, and the specific surface area is more than 300m²The water content is lower than 1.5 percent per gram. The molecular sieve is dehydrated at high temperature, and the obtained molecular sieve has more stable adsorption effect and richer pore size distribution. The invention utilizes the multi-stage pore all-silicon molecular sieve to adsorb and separate the high-boiling point iso-molecular sieveThe method for separating the isomer mixture further adopts the technical scheme that the vaporization, the adsorption and the desorption are carried out under the gas phase condition, and the temperature of the heat preservation box is 220-280 ℃; when the raw materials passing through the adsorption stage are heated, the temperature of a heating furnace at the preheating end is 200-270 ℃, the temperature of an adsorption column is 200-280 ℃, the sampling speed of the raw materials is 20-50 mL/h, and the adsorption airspeed of the raw materials is 0.03-0.15 h^-1(ii) a When the deionized water passes through the heating device in the desorption stage, the temperature of the preheating end is 220-280 ℃, the temperature of the adsorption column is 200-300 ℃, and the desorption airspeed of the deionized water is 0.15-0.3 h^-1. The temperature of the heat preservation box is preferably 230-260 ℃; the setting temperature of the preheating end heating furnace is preferably 230-260 ℃; the setting temperature of an adsorption column in the adsorption stage is preferably 250-270 ℃; the set temperature of the adsorption column in the desorption stage is preferably 220-260 ℃.

The method for separating the mixture of high-boiling-point isomers by gas-phase adsorption of the multi-stage pore all-silicon molecular sieve further adopts the technical scheme that the speed of deionized water entering the desorption preheating end through a pump in the desorption stage is 1-3 mL/min, and the desorption time of the deionized water passing through an adsorption column is 120-300 min.

The principle and the process are illustrated by taking 6-chloro-2-nitrotoluene and 2-nitro-4-chlorotoluene as examples: the mixed 6-chloro-2-nitrotoluene and 2-nitro-4-chlorotoluene enter from the upper part of an adsorption column, the temperature of the adsorption column reaches the boiling points of the 6-chloro-2-nitrotoluene and the 2-nitro-4-chlorotoluene, and two isomers are vaporized to form gas, so that mixed gas of the 6-chloro-2-nitrotoluene and the 2-nitro-4-chlorotoluene is obtained; the mixed gas of the 6-chloro-2-nitrotoluene and the 2-nitro-4-chlorotoluene enters an adsorption column, the 2-nitro-4-chlorotoluene is adsorbed, and the high-concentration 6-chloro-2-nitrotoluene mixed gas after adsorption is condensed into liquid and flows out; deionized water enters a heating furnace at a fixed flow rate, is vaporized to form water vapor, and 2-nitro-4-chlorotoluene adsorbed in the molecular sieve is swept out by a large amount of water vapor and condensed to form liquid, so that the adsorbent is regenerated and can be recycled. Raw material sample introduction speed: 20-50 mL/h; temperature of the heating furnace: 250 ℃, temperature of incubator: 250 ℃; the size of the designed adsorption column is phi 38 multiplied by 600mm, 120-420 g of adsorbent is filled, the volume is 181-636 mL, the adsorption column is filled with the adsorbent, and the upper end and the lower end of the adsorption column are isolated by using wire meshes; the temperature of the adsorption column is set to 270 ℃; the speed of deionized water entering a heating furnace through a pump is 1-3 mL/min, and the temperature of the heating furnace is set to be 250 ℃; the desorption time of the deionized water passing through the adsorption column is 120-300 min.

Compared with the prior art, the invention has the following beneficial effects:

(1) the molecular sieve not only has the characteristics and advantages of the original structure of each grade of pore channel, but also has the characteristics of more excellent property and function compared with a single pore channel structure and multifunctional synergistic effect.

(2) The hierarchical pore all-silicon molecular sieve is prepared by uniformly mixing and pressing cheap raw powder and a binder, crushing, uniformly mixing the crushed material and water according to a certain proportion, extruding into strips, polishing, dehumidifying and activating to obtain the required hierarchical pore all-silicon molecular sieve, and separating high-boiling-point isomers by using the obtained adsorbent through an adsorption-steam desorption circulation process, wherein the purity of a target product can reach more than 99%; meanwhile, the preparation and the molding of the adsorbent have the remarkable characteristics of simple process, greenness, no pollution and the like, and are extremely easy to be applied industrially.

(3) The molecular sieve after adsorption can be regenerated by purging and desorbing through steam, the collected mixture of organic matters and water can be recycled for vaporization and desorption after simple separation, and the pollution of waste water is effectively avoided. The desorbed molecular sieve can be recycled, so that the economic benefit is improved, the energy consumption is low, and the industrial requirements are met.

Detailed Description

Example 1 (hierarchical pore all-silicon molecular sieve preparation)

Weighing 400g of raw powder, 20g of attapulgite and 20g of silica gel binder in sequence, mixing, loading into a mold after uniform mixing, continuing for 1min under the pressure of 6MPa, crushing the pressed adsorbent, adding 60g of water, and extruding to obtain stripsPolishing the formed molecular sieve, cleaning residual waste on the surface of the molecular sieve by polishing, drying and dehumidifying the polished adsorbent at 60 ℃, and finally activating at 600 ℃ to dehydrate the molecular sieve at high temperature to finally obtain the adsorbent with BET of more than 300m²The molecular sieve has rich pore size distribution (82% of pore size is distributed in 1.21 +/-0.66 nm, 11% of pore size is distributed in 3.39 +/-0.49 nm, 7% of pore size is distributed in 5.93 +/-2.06 nm), the bulk density is 0.67g/mL, and the compressive strength is larger than 423g of the strip-shaped hierarchical pore all-silicon molecular sieve with the compressive strength of 40N.

Example 2

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 240 min; the chloro-o-nitrotoluene mixture (6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%)) enters a heating furnace through a syringe pump at the speed of 25mL/h to be vaporized, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 99.78%.

Example 3

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 230 ℃, the temperature of a desorption section is controlled to be 230 ℃, the temperature of a heat preservation box is controlled to be 230 ℃, the temperature of the adsorption column is controlled to be 250 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 240 min; the dichlorotoluene mixture [2, 4-dichlorotoluene (26%), 2, 5-dichlorotoluene (36%), 2, 6-dichlorotoluene (38%) ] was vaporized by a syringe pump at a rate of 25mL/h into a heating furnace to form a dichlorotoluene mixture, and after passing through an adsorption column filled with a molecular sieve, high-purity 2, 6-dichlorotoluene was collected at the bottom of the adsorption column after 104 minutes, and the content of 2, 6-dichlorotoluene in the solution was 99.69%.

Example 4

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 260 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 240 min; the chloro-o-nitrotoluene mixture (6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%)) enters a heating furnace through a syringe pump at the speed of 25mL/h to be vaporized, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 99.13%.

Example 5

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 260 ℃, the temperature of a desorption section is controlled to be 260 ℃, the temperature of a heat preservation box is controlled to be 260 ℃, the temperature of the adsorption column is controlled to be 260 ℃, and a pump is utilized to inject deionized water at the speed of 1.5mL/min into the desorption section for blowing and desorbing for 240 min; the chloro-o-nitrotoluene mixture (6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%)) enters a heating furnace through a syringe pump at the speed of 25mL/h for vaporization, and after 179 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 99.09%.

Example 6

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 120 min; the chloro-o-nitrotoluene mixture [ 6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%) ] enters a heating furnace through a syringe pump at the speed of 25mL/h to be vaporized, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 99.25%.

Example 7

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 240 ℃, the temperature of a desorption section is controlled to be 220 ℃, the temperature of a heat preservation box is controlled to be 240 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 120 min; the chloro-o-nitrotoluene mixture [ 6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%) ] enters a heating furnace through a syringe pump at the speed of 30mL/h for vaporization, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 98.76%.

Example 8

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 2mL/min for blowing and desorbing for 240 min; the chloro-o-nitrotoluene mixture [ 6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%) ] enters a heating furnace through a syringe pump at the speed of 25mL/h for vaporization, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 99.33%.

Example 9

411g of multi-stage pore all-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 250 ℃, and a pump is utilized to inject deionized water at the speed of 2mL/min into the desorption section for blowing and desorbing for 150 min; the dichlorotoluene mixture [2, 4-dichlorotoluene (26%), 2, 5-dichlorotoluene (36%), 2, 6-dichlorotoluene (38%) ] is fed into the heating furnace by means of a syringe pump at a rate of 25mL/h to be vaporized, so as to form a dichlorotoluene mixed gas, and after passing through an adsorption column filled with a molecular sieve, high-purity 2, 6-dichlorotoluene is collected at the bottom of the adsorption column after 115 minutes, and the content of 2, 6-dichlorotoluene in the solution is 99.41%.

Example 10

140g of multi-stage pore full-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end of the adsorption column are filled with about 500g of inert ceramic balls and isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to perform sweeping desorption for 120 min; the chloro-o-nitrotoluene mixture [ 6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%) ] enters a heating furnace through a syringe pump at the speed of 30mL/h for vaporization, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 93.62%.

Example 11

275g of multi-level pore full-silicon molecular sieve is filled in an adsorption column with the size of phi 38 multiplied by 600mm, the upper end and the lower end are filled with about 250g of inert porcelain balls and isolated by wire netting, the temperature of a heating furnace of an adsorption section is controlled to be 250 ℃, the temperature of a desorption section is controlled to be 250 ℃, the temperature of a heat preservation box is controlled to be 250 ℃, the temperature of the adsorption column is controlled to be 270 ℃, and deionized water is injected into the desorption section by a pump at the speed of 1.5mL/min to purge and desorb for 120 min; the chloro-o-nitrotoluene mixture [ 6-chloro-2-nitrotoluene (70%) and 2-nitro-4-chlorotoluene (30%) ] enters a heating furnace through a syringe pump at the speed of 30mL/h for vaporization, and after 184 minutes, high-purity 6-chloro-2-nitrotoluene is collected at the bottom of an adsorption column, wherein the content of the 6-chloro-2-nitrotoluene in the solution is 95.13%.