L-ethyl lactate purification process, method and purification device
Through the decolorization, rectification, drying and ion exchange steps in the levol-ethyl lactate purification process, the problems of impurities in the synthesis process are solved, the purity and quality of the product are improved, and it is suitable for high-end applications.
Patent Information
- Application Number
- CN202411716211.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-03-21
AI Technical Summary
The impurities produced by levoethyl lactate during the synthesis process reduce the purity and quality of the product, limiting its development in high-end applications.
A levoethyl lactate purification process is adopted, including decolorization, distillation, drying and ion exchange of crude levoethyl lactate, through these steps, the purity of the product is gradually improved.
Through this process, impurities can be effectively removed, the purity and quality of l-lactate can be improved, making it more suitable for high-end applications.
Smart Images
Figure CN119661357A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of ethyl lactate processing technology, and in particular to a process, method and device for purifying L-ethyl lactate. Background Art
[0002] L-ethyl lactate is an organic compound with good solubility, stability and biocompatibility. In the field of semiconductor photoresists, electronic grade ethyl lactate is used as a solvent to mix resins, photosensitizers, and additives to form liquid photoresists.
[0003] In the related art, it is also used as an auxiliary reagent for cleaning the photoresist at the edge of the substrate during the photoresist coating process. However, in the synthesis process of L-ethyl lactate, impurities are often generated, including unreacted raw materials, by-products and isomers, etc. The presence of these impurities will reduce the purity and quality of the product, thereby limiting its further development in high-end application fields.
[0004] In view of the above-mentioned related technologies, developing an efficient purification process is of vital importance to improving the quality and application value of L-ethyl lactate. Summary of the invention
[0005] In order to reduce the impurities generated during the synthesis of L-ethyl lactate, the present application provides a L-ethyl lactate purification process, method and purification device.
[0006] In the first aspect, the present application provides a process for purifying L-ethyl lactate, which adopts the following technical solution: A L-ethyl lactate purification process, comprising: Step 1, preparing crude L-ethyl lactate according to a preset synthesis method; Step 2, mixing the crude L-ethyl lactate and the decolorizing agent, heating to 50-80° C., stirring for 30-60 minutes, and then filtering to remove the decolorizing agent; Step 3, distilling the decolorized L-ethyl lactate through a distillation tower, the temperature of the distillation tower is in the range of 70-100° C., the pressure is in the range of 0.1-0.5 MPa, and collecting the fractionated high-purity L-ethyl lactate with a boiling point in the range of 140° C.-150° C.; Step 4, using a desiccant such as a molecular sieve and anhydrous magnesium sulfate to dry the distilled L-ethyl lactate; Step 5, filtering the dried L-ethyl lactate using a 0.2 micron filter membrane to remove tiny solid impurities; Step 6, removing anions and / or cations from L-ethyl lactate.
[0007] By adopting the above technical scheme, the crude L-ethyl lactate is decolorized and the decolorizing agent is removed, so that the crude L-ethyl lactate is preliminarily purified, and then distilled and purified by a distillation tower, and then the L-ethyl lactate is dried and tiny solid impurities are filtered, and finally high-purity electronic-grade L-ethyl lactate is obtained by removing metal ions.
[0008] Optionally, step 6 includes: The cations in L-ethyl lactate were removed by using electronic grade cationic resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and sulfate group as the functional group); The anions in L-ethyl lactate were removed by using electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and quaternary ammonium group as the functional group); The particle size of the cationic resin is in the range of 0.60-0.70 mm, and the particle size of the anionic resin is in the range of 0.550-0.650 mm.
[0009] By adopting the above technical scheme, the electronic grade cation resin and the electronic grade anion resin interact with the corresponding copolymers and groups to remove anions and cations from the purified L-ethyl lactate, which helps to improve the purity of the electronic grade L-ethyl lactate.
[0010] Optionally, step 6 further includes: The cations in L-ethyl lactate were removed by using cationic resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and sulfonic acid group as the functional group) with electronic grade ultrapure water; The anions in L-ethyl lactate were removed by using electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and quaternary ammonium group as the functional group); The particle size of the cationic resin is in the range of 0.60-0.70 mm, and the particle size of the anionic resin is in the range of 0.550-0.650 mm.
[0011] By adopting the above technical scheme, the pure water cationic resin has the properties of being not easy to hydrolyze and swell, and has good ion exchange performance, which helps to improve the anion and cation removal effect of L-ethyl lactate, thereby improving the purity of L-ethyl lactate.
[0012] Optionally, step 6 further includes: The cations and anions in L-ethyl lactate are removed by using polishing mixed bed resin (with PS-DVB gel as the skeleton structure and sulfonic acid group / quaternary ammonium group as the functional group). The polishing mixed bed resin is a mixture of strong acid and strong base uniform particle gel resins with special cross-linking structure and ultra-high conversion rate. The particle size range of the cation resin is 0.550-0.650mm, and the particle size range of the anion resin is 0.580-0.680mm.
[0013] In a second aspect, the present application provides a method for purifying L-ethyl lactate, using the following technical solution: A method for purifying L-ethyl lactate, which is applied to the above-mentioned L-ethyl lactate purification process, comprises: mixing crude L-ethyl lactate with a decolorizing agent, The amount of decolorizing agent is determined by matching the weight of crude L-ethyl lactate; The decolorizing agent is mixed with crude L-ethyl lactate based on the amount of the decolorizing agent, and an image of the initial mixed solution is collected; The mixed liquid is stirred by a preset stirring method until the stirring time falls into a preset reference stirring time interval, and an image of the decolorized mixed liquid is collected; Based on the comparison and analysis of the decolorized mixed solution image and the initial mixed solution image, the decolorization ratio of the crude L-ethyl lactate is determined; When the decolorization ratio of crude L-ethyl lactate is compared with the preset good decolorization ratio, a decolorization adjustment prompt or a decolorization completion prompt is issued; The filter device preset based on the decolorization completion indication filters the L-ethyl lactate, and the amount of decolorant for the crude L-ethyl lactate is adjusted based on the decolorization adjustment prompt until the decolorization completion prompt is issued.
[0014] By adopting the above technical scheme, during the decolorization process of L-ethyl lactate, a decolorant with a suitable dosage is mixed with crude L-ethyl lactate, and heated and stirred, so that the dissolution exchange efficiency of the crude L-ethyl lactate and the decolorant is improved, which helps to remove color impurities and improve the appearance of L-ethyl lactate without wasting too much decolorant.
[0015] Optionally, the preset stirring method includes: The total amount of the mixed solution is determined by calculating the amount of the decolorizing agent and the weight of the crude L-ethyl lactate; Matching is performed based on the total amount of the mixed liquid and a preset frequency database to determine the stirring frequency of the mixed liquid; Instructing a preset stirring device to stir the upper and lower layers of the mixed liquid in reverse according to a stirring frequency, and to heat the mixed liquid according to a preset temperature gradient; When the temperature of the mixed solution is within the preset high-efficiency dissolution temperature range, stop heating until the decolorization is completed.
[0016] By adopting the above technical solution, the corresponding stirring frequency is matched based on the total amount of the mixed liquid, and the stirring device is instructed to stir according to the corresponding stirring frequency, and the mixed liquid is heated according to the temperature gradient during the stirring process, so that the mixed liquid can be effectively mixed to complete the decolorization, and the decolorizing agent can accelerate the contact of molecules during the gradual increase in temperature, which helps to better improve the efficiency of the decolorization reaction of L-ethyl lactate.
[0017] Optionally, the reverse stirring of the upper and lower layers of the mixed solution includes: Instructing a preset stirring device to stir the lower mixed liquid in advance according to the stirring frequency, and collecting a stirring image of the mixed liquid for monitoring and analysis to determine the volume of the decolorized precipitate; Performing volume change analysis on the decolorized precipitate volume to determine the precipitate volume increase rate, and generating a precipitate change curve based on the analysis of the precipitate volume increase rate; When the trend of the sediment change curve is consistent with the preset gentle trend, the preset stirring device is instructed to stir the upper layer of the mixed liquid and a heating adjustment prompt is issued; Based on the heating adjustment prompt, the mixed solution is heated according to the preset temperature gradient until the temperature of the mixed solution is within the preset high-efficiency dissolution temperature range.
[0018] By adopting the above technical solution, when the mixed liquid is stirred and a decolorized precipitate is produced, the increase in the volume of the precipitate and the trend of the change curve are analyzed, and the stirring is gradually switched from the lower layer to the upper layer and gradually heated to the set high-efficiency dissolution temperature range, which helps to further improve the contact reaction between molecules. At the same time, after the precipitate is produced in the lower layer, it is not easy to move toward the upper layer under the stirring of the stirring device, so that the precipitate can be gradually deposited in the lower layer and then screened out.
[0019] Optionally, when the bleaching completion prompt is issued, it also includes: Collecting flow parameters of the mixed liquid, wherein the flow parameters include flow velocity and flow rotation direction; An analysis is performed based on the opposite direction of the flow rotation direction to determine the buffer rotation direction, and the buffer speed range required by the stirring device when matching the flow speed for buffering; Based on the buffer speed range and buffer rotation direction indication, the stirring device performs water flow buffering and issues mixed liquid monitoring prompts; The flow rate of the mixed liquid is monitored based on the mixed liquid monitoring prompt, and the stirring device is stopped for buffering when the flow rate is within a preset slow speed interval value.
[0020] By adopting the above technical solution, after the decolorizing agent and L-ethyl lactate have completed the decolorizing reaction, in order to allow the sediment to quickly stop and settle to the bottom, the stirring device performs reverse stirring and buffering on the mixed liquid so that the mixed liquid no longer produces centrifugal rotation, thereby facilitating rapid filtration and removal of the sediment.
[0021] In a third aspect, the present application provides a purification device, which is applied with the above-mentioned L-lactate purification method, comprising: Integrated decolorization module, purification and distillation module and ion exchange module; The decolorization module is used to mix the crude L-ethyl lactate and the decolorizing agent for decolorization and then transmit them to the purification and distillation module; The purification and distillation module fractionates the decolorized L-ethyl lactate and transmits the fractionated L-ethyl lactate to the ion exchange module; The ion exchange module mixes L-ethyl lactate and ion exchange resin to react, so as to remove anions and / or cations in the L-ethyl lactate.
[0022] Optionally, it also includes an image acquisition unit, a decolorant adjustment unit, a temperature adjustment unit and a stirring adjustment unit connected to the decolorization module, wherein the image acquisition unit is used to acquire images when decolorizing L-ethyl lactate, the decolorization adjustment unit is used to adjust the mixing amount of the decolorant, the temperature adjustment unit is used to adjust the temperature when L-ethyl lactate and the decolorant react, and the stirring adjustment unit is used to stir the decolorant and L-ethyl lactate when they react.
[0023] In summary, the present application includes at least one of the following beneficial technical effects: The crude L-ethyl lactate is decolorized and the decolorant is removed, so that the crude L-ethyl lactate is preliminarily purified, and then the L-ethyl lactate is purified by distillation through a distillation tower, and then the L-ethyl lactate is dried and tiny solid impurities are filtered, and finally high-purity electronic-grade L-ethyl lactate is obtained by removing metal ions; the electronic-grade cation resin and the electronic-grade anion resin interact with the corresponding copolymer and the group to remove anions and cations from the purified L-ethyl lactate, which is helpful to improve the purity of the electronic-grade L-ethyl lactate; in the process of decolorizing the L-ethyl lactate, the decolorant and the crude L-ethyl lactate are mixed according to a suitable dosage, and are heated and stirred, so that the dissolution exchange efficiency of the crude L-ethyl lactate and the decolorant is improved, which is helpful to remove color impurities and improve the appearance of the L-ethyl lactate, and it is not easy to waste too much decolorant. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a method flow chart of steps S1 to S6 in this application.
[0024] Figure 2 It is a method flow chart of steps S201 to S206 in this application.
[0025] Figure 3 It is a method flow chart of steps S2031 to S2034 in this application.
[0026] Figure 4 It is a method flow chart of steps S20331 to S20334 in this application.
[0027] Figure 5 It is a method flow chart of steps S20341 to S20344 in this application.
[0028] Figure 6 It is a connection diagram of the L-ethyl lactate purification device in this application.
[0029] Description of the drawings: 1. Decolorization module; 11. Image acquisition unit; 12. Decolorization agent adjustment unit; 13. Temperature adjustment unit; 14. Stirring adjustment unit; 2. Purification and distillation module; 3. Ion exchange module. DETAILED DESCRIPTION
[0030] In order to make the purpose, technical solutions and advantages of this application more clear, the following Figure 1-Figure 6 It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0031] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.
[0032] In the first aspect, the embodiments of the present application disclose a process for purifying L-ethyl lactate, wherein the crude L-ethyl lactate is decolorized and the decolorizer is removed, so that the crude L-ethyl lactate is preliminarily purified, and then purified by distillation through a distillation tower, and then the L-ethyl lactate is dried and tiny solid impurities are filtered out, and finally high-purity electronic-grade L-ethyl lactate is obtained by removing metal ions.
[0033] Reference Figure 1 The method flow of the L-ethyl lactate purification process comprises the following steps: Step 1, preparing crude L-ethyl lactate according to a preset synthesis method; The pre-set synthesis method is to generate an ester from L-lactic acid and ethanol under the condition of an acidic catalyst through an esterification reaction, and then obtain crude L-lactic acid ethyl ester through reduced pressure distillation.
[0034] Step 2, mixing the crude L-ethyl lactate and the decolorizing agent, heating to 50-80° C., stirring for 30-60 minutes, and then filtering to remove the decolorizing agent; The decolorizing agent can be activated carbon, flocculating decolorizing agent or diatomaceous earth. In this embodiment, flocculating decolorizing agent is selected for use. When crude L-ethyl lactate reacts with flocculating decolorizing agent, flocculent sediment will be generated. When crude L-ethyl lactate and decolorizing agent are mixed, they are heated accordingly, and the heating temperature is 50 to 80° C., so that the reaction speed between L-ethyl lactate and decolorizing agent is accelerated, which helps to improve the removal effect of color impurities, improve the appearance of L-ethyl lactate, and increase the purity of the product.
[0035] Step 3, distilling the decolorized L-ethyl lactate through a distillation tower, the temperature of the distillation tower is in the range of 70-100° C., the pressure is in the range of 0.1-0.5 MPa, and collecting the fractionated high-purity L-ethyl lactate with a boiling point in the range of 140° C.-150° C.; By pre-controlling the temperature of the distillation tower, the L-ethyl lactate in the distillation tower can be purified during the distillation process to reduce the proportion of water, and the pressure of the distillation tower is adjusted to increase the distillation rate of L-ethyl lactate during distillation. High-purity L-ethyl lactate can be extracted within the range of 140°C-150°C, which helps to further reduce impurities with a boiling point below 140 degrees Celsius in the mixture.
[0036] Step 4, using a desiccant such as a molecular sieve and anhydrous magnesium sulfate to dry the distilled L-ethyl lactate; After the distilled L-ethyl lactate is screened out by molecular sieves, the mixing of other impurity molecules can be reduced, and the use of a desiccant for drying treatment helps to reduce the moisture in the purified L-ethyl lactate, making the L-ethyl lactate more pure.
[0037] Step 5, filtering the dried L-ethyl lactate using a 0.2 micron filter membrane to remove tiny solid impurities; After the L-ethyl lactate is dried, it is filtered through a micron-sized filter membrane to further remove tiny solid particles.
[0038] Step 6, removing anions and / or cations from L-ethyl lactate.
[0039] When removing anions and cations from L-ethyl lactate, there are multiple feasible embodiments, among which embodiment 1 is: The cations in L-ethyl lactate are removed by using electronic grade cation resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and sulfate group as the functional group), and the anions in L-ethyl lactate are removed by using electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and quaternary ammonium group as the functional group). The particle size of the cation resin is in the range of 0.60-0.70mm, and the particle size of the anion resin is in the range of 0.550-0.650mm.
[0040] Embodiment 2: The cations in L-ethyl lactate are removed by using an electronic grade ultrapure water cation resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and sulfonic acid group as the functional group), and the anions in L-ethyl lactate are removed by using an electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and quaternary ammonium group as the functional group). The particle size of the cation resin is in the range of 0.60-0.70mm, and the particle size of the anion resin is in the range of 0.550-0.650mm.
[0041] Embodiment three: The cations and anions in L-ethyl lactate are removed by using polishing mixed bed resin (with PS-DVB gel as the skeleton structure and sulfonic acid group / quaternary ammonium group as the functional group). The polishing mixed bed resin is a mixture of strong acid and strong base uniform particle gel resins with special cross-linking structure and ultra-high conversion rate. The particle size range of the cation resin is 0.550-0.650mm, and the particle size range of the anion resin is 0.580-0.680mm.
[0042] Second, refer to Figure 2 Based on the same inventive concept, an embodiment of the present invention provides a method for purifying L-ethyl lactate, wherein the crude L-ethyl lactate and a decolorizing agent are mixed, comprising: Step S201: Determine the amount of decolorizing agent according to the weight of crude L-ethyl lactate; By measuring the weight of the crude L-ethyl lactate prepared in advance, the weight of the crude L-ethyl lactate can be obtained. Different weights of L-ethyl lactate need to be used in different dosages during decolorization to avoid waste or poor decolorization effect. A corresponding decolorant matching database is established in advance, and the decolorant dosage and the corresponding L-ethyl lactate weight are stored. When the L-ethyl lactate weight is input, the corresponding decolorant dosage can be matched and output for subsequent calls.
[0043] Step S202: mixing the decolorizing agent with the crude L-ethyl lactate based on the amount of the decolorizing agent, and collecting an image of the initial mixed solution; After the crude L-ethyl lactate and the decolorizing agent are mixed according to the amount of the decolorizing agent, the mixed solution is photographed by a pre-installed camera, and the photographed image is defined as the initial mixed solution image.
[0044] Step S203: stirring the mixed liquid by a preset stirring method until the stirring time falls into a preset reference stirring time interval, and collecting an image of the decolorized mixed liquid; The reference stirring time interval is a pre-set time interval value. In this embodiment, the reference stirring time interval is 30-60 minutes. The stirring method is a method of stirring the mixed liquid at a certain frequency and heating it so that the mixed liquid can accelerate the removal of impurity color. The specific steps are further described later. When the stirring time of the stirring device is within the reference stirring time interval value, the mixed liquid is imaged and collected, and the collected image is defined as a decolorized mixed liquid image.
[0045] Step S204: performing a comparative analysis based on the decolorized mixed solution image and the initial mixed solution image to determine the decolorization ratio of the crude L-ethyl lactate; By comparing and analyzing the image of the decolorized mixed liquid with the image of the initial mixed liquid, the gradient of the change in color concentration of the mixed liquid during the decolorization process can be learned. Different color change gradients represent different change ratios, and this ratio is defined as the decolorization ratio of crude L-ethyl lactate.
[0046] Step S205: when the decolorization ratio of the crude L-ethyl lactate is compared with the preset good decolorization ratio, a decolorization adjustment prompt or a decolorization completion prompt is issued; The good decolorization ratio indicates that the decolorization effect of L-ethyl lactate is good, and the L-ethyl lactate mixed solution after decolorization reaches a transparent and clear state. The specific good decolorization ratio is set by the staff, for example, the good decolorization ratio is 96%. When the decolorization ratio of crude L-ethyl lactate is equal to or greater than 96%, it means that the decolorization effect of the mixed solution is good at this time, and a decolorization completion prompt signal is issued.
[0047] When the decolorization ratio of crude L-ethyl lactate is less than 96%, it indicates that the decolorization effect is not good at this time, and it is necessary to further adjust the use of the decolorizer so that the mixed solution can be decolorized to meet a good decolorization ratio, and a decolorization adjustment prompt is issued at this time.
[0048] Step S206: filtering the L-ethyl lactate with the preset filtering device based on the decolorization completion indication, and adjusting the amount of decolorizing agent for the crude L-ethyl lactate based on the decolorization adjustment prompt until the decolorization completion prompt is issued.
[0049] After receiving the decolorization completion prompt signal, the produced decolorization precipitate needs to be filtered, and the pre-set filtering device is instructed to perform solid-liquid separation on L-ethyl lactate to remove large-diameter solid impurities. At the same time, it is gradually added to the mixed liquid according to the set dosage, and after corresponding mixing and stirring, the decolorization ratio of the crude L-ethyl lactate is analyzed again to see whether it meets the good decolorization ratio requirements, until the decolorization completion prompt is issued, indicating that it meets the requirements.
[0050] Reference Figure 3 , the preset stirring methods include: Step S2031: Calculate the total amount of the mixed solution according to the amount of the decolorizing agent and the weight of the crude L-ethyl lactate; The amount of the decolorizing agent and the weight of the crude L-ethyl lactate are summed up by weight, and the calculated value is defined as the total amount of the mixed solution.
[0051] Step S2032: matching the total amount of the mixed liquid with a preset frequency database to determine the stirring frequency of the mixed liquid; When different total amounts of mixed liquid are stirred, the stirring device has different suitable stirring frequencies, so that the mixed liquid is not easy to generate foam during the stirring process to affect the purification of L-ethyl lactate, and the efficiency of color impurity precipitation is improved. When matching the stirring frequency, the corresponding stirring frequency can be stored through a pre-established frequency database, and the total amount of mixed liquid related to the stirring frequency is stored. When the total amount of the mixed liquid is input, the corresponding stirring frequency can be automatically matched and output.
[0052] Step S2033: instructing a preset stirring device to stir the upper and lower layers of the mixed liquid in reverse order according to the stirring frequency, and heating the mixed liquid according to a preset temperature gradient; After receiving the stirring frequency, the stirring device stirs the upper and lower layers of the mixed liquid in different directions according to the stirring frequency, so that the decolorant and crude L-ethyl lactate in the mixed liquid can react more fully, thereby improving the impurity decolorization efficiency. During the heating process, heating is performed according to a pre-set temperature gradient, wherein the temperature gradient is 0-30°C, 30-50°C, 50-70°C, and 70-80°C. Gradually heating according to multiple temperature gradients helps to maintain the accuracy of temperature regulation.
[0053] Step S2034: When the temperature of the mixed solution is within the preset high-efficiency dissolution temperature range, heating is stopped until a prompt indicating that the decolorization is completed is given.
[0054] The high-efficiency dissolution temperature interval value indicates the range of interval values within which the decolorizing agent and crude L-ethyl lactate can react quickly. In this embodiment, 50-80° C. is used as the high-efficiency dissolution temperature interval value.
[0055] Reference Figure 4 , when the upper and lower layers of the mixed liquid are reversely stirred, it includes: Step S20331: instructing a preset stirring device to stir the lower mixed liquid in advance according to the stirring frequency, and collecting the stirring image of the mixed liquid for monitoring and analysis to determine the volume of the decolorized precipitate; When the lower mixed liquid is stirred in advance, a precipitate is formed in advance in the lower layer. The lower layer is monitored by a pre-set camera device, and the captured image and the image features of the precipitate are compared and analyzed to obtain the image volume of the precipitate, which is defined as the decolorized precipitate volume. In addition, when the precipitate is formed, the initial precipitate image is recorded for easy reference in subsequent analysis.
[0056] Step S20332: performing a volume change analysis on the decolorized precipitate volume to determine the precipitate volume increase rate, and generating a precipitate change curve based on the analyzed precipitate volume increase rate; As the decolorization reaction proceeds, the volume of the decolorized precipitate will continue to increase. By recording the changes in the volume of the decolorized precipitate and comparing it with the initial precipitate image, the increase in the precipitate volume can be known, and the increase rate of the precipitate volume can be obtained by dividing the increased volume by time. By establishing a coordinate system with the calculated precipitate volume increase rate and the calculated time, a curve graph of precipitate volume increase rate-time is formed.
[0057] Step S20333: When the trend of the sediment change curve is consistent with the preset gentle trend, instruct the preset stirring device to stir the upper layer of the mixed liquid and issue a heating adjustment prompt; By analyzing the changing trend of the precipitate change curve, the curve changing trend can be known, wherein the curve changing trend includes an upward trend and a gentle trend. If the precipitate change curve trend and the gentle trend are consistent, it means that the generation of precipitate no longer increases with time. At this time, the reaction efficiency of the mixed liquid needs to be further improved, and a heating adjustment prompt signal is issued.
[0058] Step S20334: heating the mixed solution according to a preset temperature gradient based on the heating adjustment prompt until the temperature of the mixed solution is within a preset high-efficiency dissolution temperature range.
[0059] After receiving the heating adjustment prompt signal, the mixed liquid is heated by a preset heating conductor until the temperature of the mixed liquid is within a preset high-efficiency dissolution temperature range, thereby improving the decolorization effect of the mixed liquid.
[0060] Reference Figure 5 , when the bleaching is completed, it also includes: Step S20341: collecting flow parameters of the mixed liquid, the flow parameters including flow velocity and flow rotation direction; During the decolorization process, the stirring device stirs the mixed liquid through the stirring blades, so that the mixed liquid produces a faster flow, accelerating the decolorization reaction, so that the mixed liquid will also flow along the stirring direction of the stirring device, and the stirring of the upper and lower layers of the mixed liquid is carried out separately. Therefore, when the decolorization completion prompt is issued, the mixed liquid is still in a centrifugal rotation state. A corresponding liquid flow rate sensor is arranged in the container to detect the flow rate of the mixed liquid, and the stirring direction before the stirring device stops stirring is collected, and the stirring direction is defined as the flow rotation direction, and the flow rotation direction and flow speed are recorded and stored, and used as flow parameters.
[0061] Step S20342: Analyze the reverse direction of the flow rotation direction to determine the buffer rotation direction, and match the flow speed to the buffer speed range required by the stirring device when performing buffering; The buffer speed range indicates the stirring rotation speed interval when the stirring device performs water flow buffering and deceleration. A corresponding buffer speed range is set for different flow speeds of the mixed liquid.
[0062] By taking the opposite direction of the flow rotation direction as the buffer rotation direction and establishing a flow velocity buffer matching database, different flow speeds are stored in the flow velocity buffer matching database, and a buffer rotation speed range that forms a mapping relationship is stored. When the flow speed is input, the corresponding buffer rotation speed range can be automatically matched and output.
[0063] Step S20343: Based on the buffering speed range and the buffering rotation direction, the stirring device is instructed to perform water flow buffering and a mixed liquid monitoring prompt is issued; After matching the corresponding buffer speed range, the stirring device is instructed to stir according to the buffer rotation direction and buffer speed range, so that the mixed liquid in the centrifugal state gradually stops rotating, which is convenient for subsequent filtration of the sediment. At the same time, a mixed liquid monitoring prompt signal is issued to prompt the flow rate to be monitored.
[0064] Step S20344: monitor the flow rate of the mixed liquid based on the mixed liquid monitoring prompt, and stop the stirring device from buffering when the flow rate is within a preset slow speed interval value.
[0065] After receiving the mixed liquid monitoring prompt signal, the pre-set flow rate sensor detects the flow rate of the mixed liquid. When the collected flow rate falls into the pre-set slow speed interval value, the buffer stirring adjustment of the stirring device is stopped. Among them, the slow speed interval value indicates that the liquid flow rate is in a speed interval range where the flow is almost stopped. At this time, the liquid is not easy to affect the movement of the sediment, which is convenient for filtering the sediment.
[0066] In the third aspect, the present application also provides a L-lactate purification device, which uses the above L-lactate purification method, referring to Figure 6 , including an integrated decolorization module 1, a purification and distillation module 2 and an ion exchange module 3, wherein the decolorization module 1 provides crude L-ethyl lactate and a decolorant for mixing and decolorizing, and then transmits them to the purification and distillation module 2, the purification and distillation module 2 fractionates the decolorized L-ethyl lactate, and transmits the fractionated L-ethyl lactate to the ion exchange module 3, and the ion exchange module 3 mixes the L-ethyl lactate and the ion exchange resin for reaction to remove anions and / or cations in the L-ethyl lactate.
[0067] It should be noted that, in the present embodiment, the decolorization module 1 is a decolorization reaction vessel, which can decolorize the crude L-ethyl lactate and filter out the decolorant, the purification and distillation module 2 is a multi-stage distillation tower, and the multi-stage distillation tower and the decolorization reaction vessel are connected to receive the decolorized L-ethyl lactate and purify it within a set range of 140-150°C to obtain L-ethyl lactate with higher purity, and the ion exchange module 3 is an ion exchange resin, and the ion exchange resin is used for anion resin, cation resin and L-ethyl lactate to carry out ion exchange reaction, thereby removing the anions and cations in the L-ethyl lactate.
[0068] In addition, the decolorization reaction container is also provided with a plurality of subunits, including an image acquisition unit 11, a decolorization agent adjustment unit 12, a temperature adjustment unit 13 and a stirring adjustment unit 14. The image acquisition unit 11 is a camera, which can continuously capture images of the reaction process of ethyl lactate. The decolorization agent adjustment unit 12 is a decolorization agent storage cylinder, which is coordinated by a control chip and a control valve to realize the dosage control of the decolorization agent, and the dosage of the decolorization agent can be increased as needed. The temperature adjustment unit 13 is a heating resistor arranged in the decolorization reaction container to improve the reaction efficiency of the decolorization agent and ethyl lactate. The stirring adjustment unit 14 is a stirring mechanism in the decolorization reaction container, which is coordinated by a servo motor and a stirring blade. The servo motor stirs after receiving the adjustment signal, which helps to speed up the reaction rate.
[0069] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.
[0070] An embodiment of the present invention provides a computer-readable storage medium storing a computer program that can be loaded by a processor and execute a method for purifying ethyl lactate.
[0071] Computer storage media include, for example, various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks or optical disks.
[0072] Based on the same inventive concept, an embodiment of the present invention provides an intelligent terminal, including a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and execute a method for purifying ethyl L-lactate.
[0073] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.
[0074] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any feature disclosed in this specification (including the abstract and drawings), unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.
Claims
1. A process for purifying L-ethyl lactate, characterized in that: include: Step 1, preparing crude L-ethyl lactate according to a preset synthesis method; Step 2, mixing the crude L-ethyl lactate and the decolorizing agent, heating to 50-80° C., stirring for 30-60 minutes, and then filtering to remove the decolorizing agent; Step 3, distilling the decolorized L-ethyl lactate through a distillation tower, the temperature of the distillation tower is in the range of 70-100° C., the pressure is in the range of 0.1-0.5 MPa, and collecting the fractionated high-purity L-ethyl lactate with a boiling point in the range of 140° C.-150° C.; Step 4, using a desiccant such as a molecular sieve and anhydrous magnesium sulfate to dry the distilled L-ethyl lactate; Step 5, filtering the dried L-ethyl lactate using a 0.2 micron filter membrane to remove tiny solid impurities; Step 6, removing anions and / or cations from L-ethyl lactate.
2. A process for purifying ethyl lactate according to claim 1, characterized in that: The step 6 comprises: The cations in L-ethyl lactate were removed by using electronic grade cationic resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and sulfate group as the functional group); The anions in L-ethyl lactate were removed by using electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton and quaternary ammonium group as the functional group); The particle size of the cationic resin is in the range of 0.60-0.70 mm, and the particle size of the anionic resin is in the range of 0.550-0.650 mm.
3. A process for purifying ethyl lactate according to claim 1, characterized in that: The step 6 also includes: The cations in L-ethyl lactate were removed by using cationic resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and sulfonic acid group as the functional group) with electronic grade ultrapure water; The anions in L-ethyl lactate were removed by using electronic grade anion resin (with macroporous polystyrene-divinylbenzene copolymer as the skeleton structure and quaternary ammonium group as the functional group); The particle size of the cationic resin is in the range of 0.60-0.70 mm, and the particle size of the anionic resin is in the range of 0.550-0.650 mm.
4. A process for purifying ethyl lactate according to claim 1, characterized in that: The step 6 also includes: The cations and anions in L-ethyl lactate are removed by using polishing mixed bed resin (with PS-DVB gel as the skeleton structure and sulfonic acid group / quaternary ammonium group as the functional group). The polishing mixed bed resin is a mixture of strong acid and strong base uniform particle gel resins with special cross-linking structure and ultra-high conversion rate. The particle size range of the cation resin is 0.550-0.650mm, and the particle size range of the anion resin is 0.580-0.680mm.
5. A method for purifying ethyl lactate, applied to the process for purifying ethyl lactate as claimed in any one of claims 1 to 4, characterized in that: When crude L-ethyl lactate is mixed with a decolorizing agent, it includes: The amount of decolorizing agent is determined by matching the weight of crude L-ethyl lactate; The decolorizing agent is mixed with crude L-ethyl lactate based on the amount of the decolorizing agent, and an image of the initial mixed solution is collected; The mixed liquid is stirred by a preset stirring method until the stirring time falls into a preset reference stirring time interval, and an image of the decolorized mixed liquid is collected; Based on the comparison and analysis of the decolorized mixed solution image and the initial mixed solution image, the decolorization ratio of the crude L-ethyl lactate is determined; When the decolorization ratio of crude L-ethyl lactate is compared with the preset good decolorization ratio, a decolorization adjustment prompt or a decolorization completion prompt is issued; Based on the decolorization completion indication, the preset filtering device filters the L-ethyl lactate, and based on the decolorization adjustment prompt, the amount of decolorant for the crude L-ethyl lactate is adjusted until the decolorization completion prompt is issued.
6. The method for purifying ethyl lactate according to claim 5, wherein: The preset stirring method includes: The total amount of the mixed solution is determined by calculating the amount of the decolorizing agent and the weight of the crude L-ethyl lactate; Matching is performed based on the total amount of the mixed liquid and a preset frequency database to determine the stirring frequency of the mixed liquid; Instructing a preset stirring device to stir the upper and lower layers of the mixed liquid in reverse according to a stirring frequency, and to heat the mixed liquid according to a preset temperature gradient; When the temperature of the mixed solution is within the preset high-efficiency dissolution temperature range, stop heating until the decolorization is completed.
7. The method for purifying ethyl lactate according to claim 6, wherein: The reverse stirring of the upper and lower layers of the mixed liquid includes: Instructing a preset stirring device to stir the lower mixed liquid in advance according to the stirring frequency, and collecting a stirring image of the mixed liquid for monitoring and analysis to determine the volume of the decolorized precipitate; Performing volume change analysis on the decolorized precipitate volume to determine the precipitate volume increase rate, and generating a precipitate change curve based on the analysis of the precipitate volume increase rate; When the trend of the sediment change curve is consistent with the preset gentle trend, the preset stirring device is instructed to stir the upper layer of the mixed liquid and a heating adjustment prompt is issued; Based on the heating adjustment prompt, the mixed solution is heated according to the preset temperature gradient until the temperature of the mixed solution is within the preset high-efficiency dissolution temperature range.
8. The method for purifying ethyl lactate according to claim 5, wherein: When the bleaching is complete, it also includes: Collecting flow parameters of the mixed liquid, wherein the flow parameters include flow velocity and flow rotation direction; An analysis is performed based on the opposite direction of the flow rotation direction to determine the buffer rotation direction, and the buffer speed range required by the stirring device when matching the flow speed for buffering; Based on the buffer speed range and buffer rotation direction indication, the stirring device performs water flow buffering and issues mixed liquid monitoring prompts; The flow rate of the mixed liquid is monitored based on the mixed liquid monitoring prompt, and the stirring device is stopped for buffering when the flow rate is within a preset slow speed interval value.
9. A device for purifying ethyl lactate, using the method according to any one of claims 5 to 8, characterized in that: include: A decolorization module (1), a purification and distillation module (2) and an ion exchange module (3) integrated into one body; The decolorization module (1) is used to mix crude L-ethyl lactate and a decolorizing agent for decolorization and then transfer the mixture to the purification and distillation module; The purification and distillation module fractionates the decolorized L-ethyl lactate and transmits the fractionated L-ethyl lactate to the ion exchange module (3); The ion exchange module (3) performs a mixed reaction on L-ethyl lactate and an ion exchange resin to remove anions and / or cations in the L-ethyl lactate.
10. A device for purifying ethyl lactate according to claim 9, characterized in that: It also comprises an image acquisition unit (11), a decolorant adjustment unit (12), a temperature adjustment unit (13) and a stirring adjustment unit (14) connected to the decoloration module (1); the image acquisition unit (11) is used to acquire images when decolorizing L-ethyl lactate; the decoloration adjustment unit is used to adjust the mixing amount of the decolorant; the temperature adjustment unit (13) is used to adjust the temperature when L-ethyl lactate and the decolorant react; and the stirring adjustment unit (14) is used to stir the decolorant and L-ethyl lactate when they react.