阅读说明：本技术 一种模拟移动床装置及分离多组分二元醇的方法 (Simulated moving bed device and method for separating multicomponent dihydric alcohol ) 是由 王利国 熊佩 曹妍 贺鹏 李会泉 陈家强 徐爽 于 2019-10-08 设计创作，主要内容包括：本发明提供了一种模拟移动床装置及分离多组分二元醇的方法。所述模拟移动床装置包括至少四个内装吸附剂的层析柱,每一个所述层析柱具有至少两个进料通道和至少三个出料通道,且所述层析柱之间通过连接通道相互串联；所述层析柱的进料通道与出料通道上,以及相邻的层析柱之间的连接通道上设置有控制通道开关的阀门。所述方法为：采用所述模拟移动床装置,将多组分二元醇通入所述模拟移动床装置的层析柱中,然后再通入解析剂进行洗脱,不同成分的抽出液分别从所述层析柱的不同出料通道流出,从而分离所述多组分二元醇。本发明提供的模拟移动床装置可通过泵和阀门的切换,自主选择不同的模式进行分离操作,满足不同的分离需求。(The invention provides a simulated moving bed device and a method for separating multi-component dihydric alcohol. The simulated moving bed device comprises at least four chromatographic columns filled with adsorbents, each chromatographic column is provided with at least two feeding channels and at least three discharging channels, and the chromatographic columns are connected in series through connecting channels; valves for controlling the opening and closing of the channels are arranged on the feeding channel and the discharging channel of the chromatographic columns and on the connecting channel between the adjacent chromatographic columns. The method comprises the following steps: and (2) introducing the multi-component dihydric alcohol into a chromatographic column of the simulated moving bed device by adopting the simulated moving bed device, then introducing a resolving agent for elution, and respectively allowing extract liquids with different components to flow out from different discharge channels of the chromatographic column so as to separate the multi-component dihydric alcohol. The simulated moving bed device provided by the invention can automatically select different modes to carry out separation operation by switching the pump and the valve, thereby meeting different separation requirements.)

1. A simulated moving bed apparatus, characterized in that the simulated moving bed apparatus comprises at least four chromatographic columns filled with adsorbent, each chromatographic column has at least two feed channels and at least three discharge channels, and the chromatographic columns are connected in series with each other through connecting channels;

valves for controlling the opening and closing of the channels are arranged on the feeding channel and the discharging channel of the chromatographic columns and on the connecting channel between the adjacent chromatographic columns.

2. A simulated moving bed apparatus according to claim 1, wherein said adsorbent is selected from one or a combination of at least two of an adsorbent resin or a molecular sieve;

preferably, the adsorption resin is selected from one or a combination of at least two of SP70 resin of Mitsubishi chemical holdings, DA201-A resin of Jiangsu Suqing Water treatment engineering group, and DA201-C resin of Jiangsu Suqing Water treatment engineering group;

preferably, the molecular sieve is selected from one or a combination of at least two of 13X molecular sieve, NaY molecular sieve, 4A molecular sieve, 5A molecular sieve, MCM-22 molecular sieve, SAPO-11 molecular sieve and SAOO-34 molecular sieve;

preferably, the chromatographic column of the simulated moving bed device is also connected with a back pressure valve for regulating the operating pressure in the chromatographic column.

3. A method of separating a multicomponent diol, the method comprising: the simulated moving bed device of claim 1 or 2, wherein the multi-component diol is introduced into a chromatographic column of the simulated moving bed device, then a resolving agent is introduced for elution, and extracts with different components respectively flow out from different discharge channels of the chromatographic column, so that the multi-component diol is separated.

4. The method according to claim 3, characterized in that it is:

using the simulated moving bed apparatus of claim 1 or 2, introducing a multi-component glycol from a multi-component glycol feed channel of a first chromatography column into the first chromatography column, the discharge channel of the first chromatography column and the feed channels of other chromatography columns being kept closed; after the multi-component dihydric alcohol feeding is finished, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column, continuously introducing an analytic agent from the analytic agent feeding channel of the first chromatographic column for elution, and keeping the states of other chromatographic columns unchanged; introducing multi-component dihydric alcohol and a resolving agent into the next chromatographic column at intervals by the same method as the first chromatographic column until all the chromatographic columns are continuously separated after the multi-component dihydric alcohol and the resolving agent are introduced;

the interval time deltat between the feeds of adjacent columns₁＝t₁/n₁Wherein t is₁Is the time from the beginning of the introduction of the multi-component dihydric alcohol into a chromatographic column to the end of the separation of the multi-component dihydric alcohol in the chromatographic column, n₁The number of chromatographic columns in the simulated moving bed device;

and the connecting channels between adjacent chromatographic columns are kept closed during the whole separation process; the discharge channel of each chromatographic column is correspondingly opened or closed according to the components of the extract; and after the multi-component dihydric alcohol in any chromatographic column is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

5. The method according to claim 3, characterized in that it is:

the simulated moving bed apparatus according to claim 1 or 2, wherein the column of the simulated moving bed apparatus is divided into n by using two adjacent columns as a zone₂Each zone;

introducing multi-component dihydric alcohol from a multi-component dihydric alcohol feeding channel of a first chromatographic column of a first zone, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column after the multi-component dihydric alcohol feeding is finished, and continuously introducing a resolving agent from a resolving agent feeding channel of the first chromatographic column for elution; introducing multi-component dihydric alcohol and a resolving agent into the next zone at intervals by the same method as the first zone until the multi-component dihydric alcohol and the resolving agent are introduced into all the zones and then continuously separated;

interval time delta t of feeding of adjacent zones₂＝t₂/n₂Wherein t is₂Is the time from the beginning of the introduction of the multicomponent diol into a zone to the end of the separation of the multicomponent diol in that zone, n₂The number of areas in the simulated moving bed device is the number of areas;

in the whole separation process, the connecting channel between two chromatographic columns in one zone is kept open, and the connecting channel between two adjacent zones is kept closed; the discharge channel of the first chromatographic column and the feed channel of the second chromatographic column in one zone are kept closed; the discharge channel of the second chromatographic column in each zone is opened or closed correspondingly according to the components of the extract; and after the multi-component dihydric alcohol in any one zone is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

6. The method according to claim 3, characterized in that it is:

a simulated moving bed apparatus according to claim 1 or 2, wherein two adjacent columns are provided as one columnA zone dividing the column of the simulated moving bed apparatus into n₃Each zone;

introducing multi-component dihydric alcohol from a multi-component dihydric alcohol feeding channel of a first chromatographic column of a first zone, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column after the multi-component dihydric alcohol feeding is finished, and continuously introducing a resolving agent from a resolving agent feeding channel of the first chromatographic column for elution; introducing multi-component dihydric alcohol and a resolving agent into the next zone at intervals by the same method as the first zone until the multi-component dihydric alcohol and the resolving agent are introduced into all the zones and then continuously separated;

interval time delta t of feeding of adjacent zones₃＝t₃/n₃Wherein t is₃The time from the beginning of the introduction of the multi-component diol into the first chromatographic column in one zone to the completion of the separation of the multi-component diol in the chromatographic column, n₃The number of areas in the simulated moving bed device is the number of areas;

and the connecting channel between two adjacent zones is kept closed during the whole separation process; the multi-component glycol feed channel of the second chromatography column in one zone remains closed and the desorbent feed channel remains open; the single-component extract of the first chromatographic column in each zone flows out from the discharge channel of the first chromatographic column, and the multi-component extract flows into the second chromatographic column from the connecting channel between the two chromatographic columns; the discharge channels of the two chromatographic columns in each zone are correspondingly opened or closed according to the components of the extract; and after the multi-component dihydric alcohol in the first chromatographic column in any one zone is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

7. The method according to any one of claims 3 to 6, further comprising distilling off the resolving agent in the extract to obtain a diol component.

8. The method according to any one of claims 3 to 7, wherein the resolving agent is selected from one or a combination of at least two of methanol, ethanol, n-propanol, isopropanol and water;

preferably, the multicomponent glycol includes at least two of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 2, 3-butanediol, and 1, 4-butanediol.

9. The method of any of claims 3-8, wherein the multicomponent diol is fed at a rate of 0.1-10 mL/min;

preferably, the feeding rate of the resolving agent is 0.1-10 mL/min.

10. A method according to any one of claims 3-9, characterized in that the simulated moving bed unit is operated at a pressure of 5MPa or less and at a temperature of 20-160 ℃.

Technical Field

The invention belongs to the technical field of mixed alcohol separation, and particularly relates to a simulated moving bed device and a method for separating multi-component dihydric alcohol.

Background

In the process of preparing ethylene glycol from coal, mixed alcohol is used as a main byproduct, and a large amount of low-value utilization is realized, so that the loss of ethylene glycol is large. Among them, the polyhydric alcohols such as ethylene glycol, 1, 2-propylene glycol, 1, 2-butanediol, 2, 3-butanediol, etc. have wide application in the fields of energy, chemical industry, materials, etc., and are one of the chemical products which are mainly imported in China. Ethylene glycol is an important bulk petrochemical raw material, can be used for producing products such as polyester fibers, antifreeze, unsaturated polyester resin, lubricants and the like, and a main byproduct, namely multi-component mixed alcohol, is a chemical product with great application potential.

At present, the two main process routes for producing ethylene glycol at home and abroad are as follows: a syngas feed line and a biomass feed line. The method for directly synthesizing the glycol by utilizing the synthesis gas is called as a direct synthesis method, is the simplest and most effective glycol synthesis method, and has low reaction selectivity and conversion rate. The process for preparing the ethylene glycol based on the biomass raw material has various routes, including preparing ethylene by dehydrating bioethanol, and preparing the ethylene glycol by hydrating ethylene oxide through ethylene epoxidation; gasifying biomass to prepare synthesis gas, and hydrogenating the synthesis gas by oxalate to prepare glycol; preparing ethylene glycol by directly fermenting biomass; preparing glyoxal by biomass fermentation, preparing glycol by glyoxal reduction and the like. In addition, the byproduct glycerol of the biodiesel, which is used as a biomass platform chemical, can be used for preparing ethylene glycol through catalytic hydrocracking.

The mixed alcohol prepared by the method usually contains various alcohols such as ethylene glycol, 1, 2-propylene glycol, 1, 2-butanediol, 2, 3-butanediol, methanol, ethanol and the like, wherein part of the alcohols have similar boiling points, and a high reflux ratio and theoretical plate number are required when the mixed alcohol is separated by a common rectification method. CN 108017517A discloses a method for separating low-concentration 1, 2-butanediol from ethylene glycol by adopting an azeotropic distillation method, which takes dimethyl oxalate serving as a hydrogenation reaction raw material as an entrainer, obtains a mixture of the ethylene glycol and the dimethyl oxalate serving as the entrainer from the bottom of a tower, and obtains a mixture of the 1, 2-butanediol and the dimethyl oxalate from the top of the tower. CN 105541551A discloses a new method, a process and a device for the reactive distillation separation and refining of ethylene glycol and 1, 2-butanediol, which adopts an acetal or ketal reversible reaction, firstly, a glycol mixture reacts with aldehyde or ketone in a reactive distillation tower to generate an acetal/ketone mixture, the acetal/ketone mixture is separated by a distillation method, and then, high-purity ethylene glycol and 1, 2-butanediol products are obtained by respectively carrying out reactive distillation hydrolysis. Although different alcohols can be effectively separated by azeotropic distillation or reactive distillation, the azeotropic distillation method has harsh separation conditions and poor separation effect, the requirements on the separation conditions of reactive distillation are high, the yield of ethylene glycol is low, and the problems of high energy consumption exist.

CN 102372599a discloses a method for separating ethylene glycol and butanediol, which adopts a simulated moving bed device with built-in adsorbent to realize the separation of ethylene glycol and butanediol. However, the adopted simulated moving bed device is of a series structure and is single in structure, the device needs to be stopped repeatedly to add and separate raw materials, the continuous operation cannot be realized, the separation efficiency is low, and the further improvement is awaited.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a simulated moving bed device and a method for separating multicomponent dihydric alcohol. The simulated moving bed device can be used for separating multicomponent dihydric alcohol, and different modes can be independently selected for separation operation by switching the pump and the valve, so that different separation requirements are met.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a simulated moving bed device, which comprises at least four chromatographic columns filled with adsorbents, wherein each chromatographic column is provided with at least two feeding channels and at least three discharging channels, and the chromatographic columns are connected in series with each other through connecting channels;

valves for controlling the opening and closing of the channels are arranged on the feeding channel and the discharging channel of the chromatographic columns and on the connecting channel between the adjacent chromatographic columns.

The simulated moving bed device provided by the invention can realize different separation modes by switching the pump and the valve, and all chromatographic columns can run simultaneously and continuously discharge to achieve the purpose of continuous separation, thereby improving the separation efficiency.

The term "adjacent chromatographic columns" in the present invention refers to chromatographic columns which are directly connected by connecting channels in a series structure of chromatographic columns.

In the present invention, the number of the chromatography columns is at least four, and may be, for example, 4, 6, 8, 10, 12, 14, 16, or 20.

The number of the feed channels is at least two, and may be, for example, 2,3, 4, or 5, etc. When the simulated moving bed device provided by the invention is used for multi-component diol separation, at least one multi-component diol feed channel and one resolving agent feed channel are needed, and the redundant feed channels can be used as spare channels for feeding extract which is not completely separated.

The extract liquid of different components needs to flow out from different discharge channels, so that the more components of the multi-component dihydric alcohol, the more discharge channels are needed. When the multi-component diol contains two diol components, the extraction liquid is respectively the two diol components and the mixture component of the two diol components, so that the number of the discharge channels is at least three, and for example, the number of the discharge channels can be 3, 4, 5, 6, 7 or 8.

As a preferred technical scheme of the invention, the adsorbent is selected from one or a combination of at least two of adsorption resin or molecular sieve.

Preferably, the adsorption resin is selected from one or a combination of at least two of SP70 resin of Mitsubishi chemical holdings, DA201-A resin of Jiangsu Suqing Water treatment engineering group Co., Ltd, DA201-C resin of Jiangsu Suqing Water treatment engineering group Co., Ltd.

Preferably, the molecular sieve is selected from one or a combination of at least two of 13X molecular sieve, NaY molecular sieve, 4A molecular sieve, 5A molecular sieve, MCM-22 molecular sieve, SAPO-11 molecular sieve and SAOO-34 molecular sieve.

Preferably, the chromatographic column of the simulated moving bed device is also connected with a back pressure valve for regulating the operating pressure in the chromatographic column.

In a second aspect, the present invention provides a method for separating multicomponent glycols, the method comprising: by adopting the simulated moving bed device of the first aspect of the invention, the multi-component dihydric alcohol is introduced into the chromatographic column of the simulated moving bed device, then the resolving agent is introduced for elution, and extract liquids with different components respectively flow out from different discharge channels of the chromatographic column, thereby separating the multi-component dihydric alcohol.

In one embodiment of the present invention, the method is:

by adopting the simulated moving bed device of the first aspect of the invention, multi-component dihydric alcohol is introduced into the first chromatographic column from the multi-component dihydric alcohol feeding channel of the first chromatographic column, and the discharging channel of the first chromatographic column and the feeding channels of other chromatographic columns are kept closed; after the multi-component dihydric alcohol feeding is finished, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column, continuously introducing an analytic agent from the analytic agent feeding channel of the first chromatographic column for elution, and keeping the states of other chromatographic columns unchanged; introducing multi-component dihydric alcohol and a resolving agent into the next chromatographic column at intervals by the same method as the first chromatographic column until all the chromatographic columns are continuously separated after the multi-component dihydric alcohol and the resolving agent are introduced;

the interval time deltat between the feeds of adjacent columns₁＝t₁/n₁Wherein t is₁Is the time from the beginning of the introduction of the multi-component dihydric alcohol into a chromatographic column to the end of the separation of the multi-component dihydric alcohol in the chromatographic column, n₁The number of chromatographic columns in the simulated moving bed device;

and the connecting channels between adjacent chromatographic columns are kept closed during the whole separation process; the discharge channel of each chromatographic column is correspondingly opened or closed according to the components of the extract; and after the multi-component dihydric alcohol in any chromatographic column is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

The separation mode is a multi-column parallel flow type, and a plurality of chromatographic columns are connected in parallel and can run simultaneously without mutual influence. Through setting up the interval time of feeding to adjacent chromatographic column, make each chromatographic column have different separation progress, can guarantee that device when steady operation, discharge channel continuous ejection of compact reaches continuous separation's purpose.

In one embodiment of the present invention, the method is:

with the simulated moving bed apparatus according to the first aspect of the present invention, two adjacent chromatography columns are used as one zone, and the chromatography column of the simulated moving bed apparatus is divided into n₂Each zone;

introducing multi-component dihydric alcohol from a multi-component dihydric alcohol feeding channel of a first chromatographic column of a first zone, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column after the multi-component dihydric alcohol feeding is finished, and continuously introducing a resolving agent from a resolving agent feeding channel of the first chromatographic column for elution; introducing multi-component dihydric alcohol and a resolving agent into the next zone at intervals by the same method as the first zone until the multi-component dihydric alcohol and the resolving agent are introduced into all the zones and then continuously separated;

interval time delta t of feeding of adjacent zones₂＝t₂/n₂Wherein t is₂Is the time from the beginning of the introduction of the multicomponent diol into a zone to the end of the separation of the multicomponent diol in that zone, n₂The number of areas in the simulated moving bed device is the number of areas;

in the whole separation process, the connecting channel between two chromatographic columns in one zone is kept open, and the connecting channel between two adjacent zones is kept closed; the discharge channel of the first chromatographic column and the feed channel of the second chromatographic column in one zone are kept closed; the discharge channel of the second chromatographic column in each zone is opened or closed correspondingly according to the components of the extract; and after the multi-component dihydric alcohol in any one zone is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

The separation mode is 'regional parallel flow type', the chromatographic columns in one region are in a serial structure, and the regions are in a parallel structure. The separation degree can be increased by connecting two columns in series, and the separation effect is improved; through setting the interval time of feeding of adjacent district, make each district have different separation progress, can guarantee that discharge channel discharges in succession when the device is in steady operation, reach the purpose of continuous separation.

In one embodiment of the present invention, the method is:

with the simulated moving bed apparatus according to the first aspect of the present invention, two adjacent chromatography columns are used as one zone, and the chromatography column of the simulated moving bed apparatus is divided into n₃Each zone;

introducing multi-component dihydric alcohol from a multi-component dihydric alcohol feeding channel of a first chromatographic column of a first zone, closing the multi-component dihydric alcohol feeding channel of the first chromatographic column after the multi-component dihydric alcohol feeding is finished, and continuously introducing a resolving agent from a resolving agent feeding channel of the first chromatographic column for elution; introducing multi-component dihydric alcohol and a resolving agent into the next zone at intervals by the same method as the first zone until the multi-component dihydric alcohol and the resolving agent are introduced into all the zones and then continuously separated;

interval time delta t of feeding of adjacent zones₃＝t₃/n₃Wherein t is₃The time from the beginning of the introduction of the multi-component diol into the first chromatographic column in one zone to the completion of the separation of the multi-component diol in the chromatographic column, n₃The number of areas in the simulated moving bed device is the number of areas;

and the connecting channel between two adjacent zones is kept closed during the whole separation process; the multi-component glycol feed channel of the second chromatography column in one zone remains closed and the desorbent feed channel remains open; the single-component extract of the first chromatographic column in each zone flows out from the discharge channel of the first chromatographic column, and the multi-component extract flows into the second chromatographic column from the connecting channel between the two chromatographic columns; the discharge channels of the two chromatographic columns in each zone are correspondingly opened or closed according to the components of the extract; and after the multi-component dihydric alcohol in the first chromatographic column in any one zone is separated, repeatedly introducing the multi-component dihydric alcohol and introducing the resolving agent for elution.

The separation mode is a 'region coupling type', the regions are in a parallel connection structure, the first chromatographic column in one region is a main separation column, and separated single-component extract flows out from a discharge channel of the chromatographic column; when the multi-component extract is separated, the discharge channel of the first chromatographic column is closed, and the connecting channel between the two chromatographic columns is opened, so that the multi-component extract enters the second chromatographic column for further separation, and the separation effect can be further improved. Through setting the interval time of feeding of adjacent district, make each district have different separation progress, can guarantee that discharge channel discharges in succession when the device is in steady operation, reach the purpose of continuous separation.

In the present invention, "one-component extract" refers to a mixed solution of a single diol component and a resolving agent, and "multi-component extract" refers to a mixed solution of a mixed component of a plurality of diols and a resolving agent.

As a preferred embodiment of the present invention, the method further comprises distilling off the resolving agent in the extract to obtain the diol component.

In a preferred embodiment of the present invention, the resolving agent is one or a combination of at least two selected from methanol, ethanol, n-propanol, isopropanol and water.

As a preferred embodiment of the present invention, the multicomponent diol includes at least two of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 2, 3-butanediol, and 1, 4-butanediol.

As a preferred technical scheme of the invention, the feeding rate of the multicomponent dibasic alcohol is 0.1-10 mL/min; for example, it may be 0.1mL/min, 0.5mL/min, 1mL/min, 1.5mL/min, 2mL/min, 2.5mL/min, 3mL/min, 4mL/min, 5mL/min, 6mL/min, 7mL/min, 8mL/min, 9mL/min or 10 mL/min.

Preferably, the feeding rate of the resolving agent is 0.1-10 mL/min; 0.1-10 mL/min; for example, it may be 0.1mL/min, 0.5mL/min, 1mL/min, 1.5mL/min, 2mL/min, 2.5mL/min, 3mL/min, 4mL/min, 5mL/min, 6mL/min, 7mL/min, 8mL/min, 9mL/min or 10 mL/min.

As a preferable embodiment of the present invention, the operating pressure of the simulated moving bed apparatus is not more than 5MPa, and may be, for example, 5MPa, 4.5MPa, 4MPa, 3.5MPa, 3MPa, 2.5MPa, 2MPa, 1.5MPa or 1 MPa; the operation temperature is 20-160 deg.C, such as 20 deg.C, 30 deg.C, 40 deg.C, 50 deg.C, 60 deg.C, 70 deg.C, 80 deg.C, 90 deg.C, 100 deg.C, 110 deg.C, 120 deg.C, 130 deg.C, 140 deg.C, 150 deg.C or 160 deg.C.

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

the simulated moving bed device provided by the invention can be used for separating multi-component dihydric alcohol, and different modes can be independently selected for separation operation by switching the pump and the valve, so that different separation requirements are met. According to the method for separating the multi-component dihydric alcohol, each chromatographic column is arranged in parallel, or each chromatographic column is divided into a plurality of zones, each zone is arranged in parallel, the feeding time of the adjacent chromatographic columns or zones generates certain intervals, each chromatographic column or zone has different separation progress, the continuous discharging of a discharging channel can be ensured when the device runs stably, and the purpose of continuous separation is achieved.

Drawings

FIG. 1 is a schematic structural diagram of a simulated moving bed apparatus provided in example 1 of the present invention;

wherein, the channel A and the channel B are feeding channels, the channel D, the channel E and the channel F are discharging channels, and the column I, the column II, the column III, the column IV, the column V, the column VI, the column VII and the column VIII are chromatographic columns.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. It should be understood by those skilled in the art that the specific embodiments are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.