CN114471434A - Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate - Google Patents
Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate Download PDFInfo
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- 239000004310 lactic acid Substances 0.000 title claims abstract description 55
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- 238000007363 ring formation reaction Methods 0.000 title claims abstract description 25
- 238000005336 cracking Methods 0.000 title claims abstract description 20
- 230000007062 hydrolysis Effects 0.000 claims abstract description 51
- 239000000463 material Substances 0.000 claims abstract description 33
- 238000003756 stirring Methods 0.000 claims abstract description 5
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 28
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- 239000012295 chemical reaction liquid Substances 0.000 claims description 8
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- 238000003776 cleavage reaction Methods 0.000 claims description 7
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- 206010057040 Temperature intolerance Diseases 0.000 claims description 3
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- 230000008543 heat sensitivity Effects 0.000 claims 1
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- 229920000747 poly(lactic acid) Polymers 0.000 abstract description 10
- 239000004626 polylactic acid Substances 0.000 abstract description 10
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical compound CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 abstract description 9
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0046—Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/18—Stationary reactors having moving elements inside
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/28—Moving reactors, e.g. rotary drums
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
- B01J2219/00076—Controlling the temperature by indirect heating or cooling employing heat exchange fluids with heat exchange elements inside the reactor
- B01J2219/00081—Tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
- B01J2219/00087—Controlling the temperature by indirect heating or cooling employing heat exchange fluids with heat exchange elements outside the reactor
- B01J2219/00094—Jackets
Abstract
The invention discloses a hydrolysis reaction device for a lactic acid oligomer cracking cyclization substrate, and belongs to the technical field of polylactic acid production. Through the rotation of the spiral shell area and the body in the one-level converter hydrolysis reactor, in time with being thick form semifluid state's material transfer out in the upper reaches schizolysis cyclization reactor, both avoided schizolysis cyclization reactor to take place to solidify and/or coking phenomenon, guaranteed again that viscous material is intensive mixing and be heated evenly in the stove, effectively promote going on of one-level hydrolysis reaction, the material viscosity before finally getting into second grade hydrolysis reaction cauldron is by greatly reduced, the resistance of agitator stirring correspondingly reduces, the electric energy has been saved, simultaneously because the interior mass transfer of second grade hydrolysis reaction cauldron, the improvement of heat transfer, and the autocatalysis phenomenon that the acidity increase arouses, make second grade hydrolysis reaction will be more rapid and thorough. The invention has the advantages of large load adjustment elasticity, simple operation, small equipment investment and energy saving, and can effectively improve the utilization rate of lactic acid or the total yield of lactide finally.
Description
Technical Field
The invention belongs to the technical field of polylactic acid production, and relates to a hydrolysis reaction device for a lactic acid oligomer cracking cyclization substrate.
Background
The polylactic acid is a novel biodegradable polyester high molecular compound polymerized by using lactic acid as a monomer, can be hydrolyzed under the catalysis of enzymes or acids and bases in microorganisms or organisms to finally form carbon dioxide and water, realizes the circulation in the nature, is harmless and nontoxic to the human body, has no pollution to the environment, and is a degradable material with great development potential. In application, polylactic acid can be applied to the field of medical and medical equipment materials, and also can be applied to the field of film products, such as agricultural mulching films, shopping bags, express delivery bags, packaging bags, freshness protection bags and the like, and can also be processed into downhole tool components for hydrocarbon resource recovery, temporary plugging agent materials and the like. Therefore, the polylactic acid serving as a novel degradable material has considerable economic benefits and good application prospects, and is an effective way for solving the problem of environmental pollution caused by plastic wastes and relieving the shortage of petroleum resources.
At present, two methods are mainly used for synthesizing polylactic acid: direct polycondensation of lactic acid and indirect polycondensation of lactic acid through the intermediate lactide. In the direct polycondensation method, since impurities exist in the system and the lactic acid polycondensation reaction is a reversible reaction, it is difficult to obtain polylactic acid having a high molecular weight. The indirect polycondensation method is used for synthesizing the polylactic acid, no special auxiliary agent is needed to be introduced, and the molecular weight of the product can reach hundreds of thousands or even millions. Therefore, the indirect polycondensation method is the most globally used polylactic acid production method at present. However, the indirect polycondensation process is lengthy, the reaction conditions are severe, and the requirements for equipment are high. Particularly, when the lactic acid raw material is cracked into gas-phase lactide generated by the ring reactor, the lactic acid cannot be completely converted into the lactide, a part of lactic acid oligomer with higher molecular weight is generated, and side reactions such as high-temperature oxidation carbonization and the like also occur. These side reaction products are usually dark brown viscous liquids, and as the viscosity of the material system increases, if the material system cannot be discharged in time, the solidification and/or coking at the bottom of the reaction kettle can be caused, so that the pipeline blockage is caused, and the yield and the purity of the lactide are seriously influenced. Generally, in a single-pass conversion of lactic acid to lactide, there is 30% conversion to substrate, which if discarded increases the raw material cost for lactide production and causes environmental damage. Therefore, there is a strong need in the art to provide a highly efficient method for hydrolyzing lactic acid oligomers to cleave cyclized substrates, thereby increasing the overall yield of lactide and reducing environmental pollution.
Disclosure of Invention
The present invention is directed to overcome the above disadvantages of the prior art and to provide a hydrolysis reaction apparatus for the cleavage of a cyclized substrate by a lactic acid oligomer.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose: a hydrolysis reaction device of lactic acid oligomer cracking cyclization substrate comprises a primary converter hydrolysis reactor, a secondary hydrolysis reaction kettle, a liquid filter and a falling film evaporator;
the feeding end of the first-stage converter hydrolysis reactor is provided with a feeding hole, a cracking cyclization substrate pipeline, a lactic acid prepolymerization process evaporation water pipeline and an outlet of a reflux water pump, the discharging end of the first-stage converter hydrolysis reactor is provided with a discharging hole and connected with a feeding pipeline of a second-stage hydrolysis reaction kettle, a 2# heating sleeve is also arranged on the outer side of the discharging end, and the 2# heating sleeve is communicated with the 1# heating sleeve through a pipeline so as to prevent the materials from being solidified and blocked;
a stirrer, a feeding pipe, a coil heater and an overflow weir are arranged in the secondary hydrolysis reaction kettle; the stirrer is connected with a No. 2 driving motor and drives the stirrer to rotate and stir; the inlet of the feeding pipe is connected with the outlet of the discharge end of the primary converter hydrolysis reactor, and the outlet of the feeding pipe is inserted into the bottom of the secondary hydrolysis reactor and is close to the bottom surface; the coil heater is positioned below the liquid level of the secondary hydrolysis reaction kettle and provides heat for the hydrolysis reaction; the overflow weir is arranged at the upper part of the secondary hydrolysis reaction kettle, and the reaction liquid overflows out of the reaction kettle;
the inlet of the liquid filter is connected with the outlet of an overflow weir of the secondary hydrolysis reaction kettle, the solid-phase outlet of the liquid filter is connected with a waste solid pipeline, and the liquid-phase outlet of the liquid filter is connected with the upper liquid-phase inlet of the falling-film evaporator;
an outlet at the bottom of the falling-film evaporator is sequentially connected with a No. 1 gas-liquid separator and an inlet of a circulating pump, and an outlet pipeline of the circulating pump is divided into two branches which are respectively connected with a liquid-phase inlet at the upper part of the falling-film evaporator and a hydrolysate pipeline; the gas phase outlet at the top of the 1# gas-liquid separator is sequentially connected with inlets of a first-stage condenser, a 2# gas-liquid separator, a second-stage condenser, a 3# gas-liquid separator and a vacuum pump, and the liquid phase outlet of the 3# gas-liquid separator is sequentially connected with inlets of the 2# gas-liquid separator and a reflux water pump.
Further, the primary converter hydrolysis reactor body is of a cylindrical structure, a No. 1 heating sleeve is arranged on the outer side of the primary converter hydrolysis reactor body, a rotating shaft is arranged along the axial direction of the primary converter hydrolysis reactor body and is connected with a No. 1 driving motor, the rotating shaft is driven by the No. 1 driving motor to further drive the primary converter hydrolysis reactor body and a spiral belt to rotate, and the spiral belt is spirally wound and distributed on a central shaft along the axial direction of the central shaft;
furthermore, the viscosity of the reaction liquid in the first-stage converter hydrolysis reactor is far greater than that of the reaction liquid in the second-stage hydrolysis reactor, and the fluidity of the reaction liquid is driven by a spiral belt; the viscosity of the reaction liquid in the secondary hydrolysis reaction kettle is far greater than that of the liquid in the falling film evaporator, and the stirrer adopts an anchor stirrer suitable for high-viscosity liquid to drive the fluidity of the high-viscosity liquid.
Furthermore, the secondary condenser adopts low-temperature refrigerant as a refrigerant to prevent easily solidified substances from entering the vacuum pump.
Further, the reaction product after being fully hydrolyzed by the first-stage converter hydrolysis reactor and the second-stage hydrolysis reaction kettle is dehydrated, and a falling film evaporator suitable for high-viscosity and high-heat-sensitivity materials is adopted to carry out vacuum evaporation on the reaction product.
Furthermore, the reaction water injected into the first-stage converter hydrolysis reactor and the second-stage hydrolysis reactor respectively comes from the pipeline of the upstream lactic acid prepolymerization unit and the process distilled water of the falling film evaporator, and the water of the first-stage converter hydrolysis reactor and the process distilled water of the falling film evaporator contains a small amount of lactic acid and is acidic.
Compared with the prior art, the invention has the following beneficial effects:
the invention has large load adjustment elasticity, simple operation, small equipment investment and energy saving, timely transfers the viscous semi-fluid material in the upstream cracking and cyclization reactor out through the rotation of the helical ribbon in the primary converter hydrolysis reactor, can effectively avoid the solidification and/or coking phenomenon of the cracking and cyclization reactor caused by the further aggravation of the reaction degree of the material, the viscous semi-fluid material advances forward under the driving of the helical ribbon, and can be gradually hydrolyzed in the advancing process, simultaneously, the rotation of the furnace body can increase the heated uniformity and promote the further mixing and reaction of the reaction materials, the viscosity of the reaction liquid before finally entering the secondary hydrolysis reaction kettle is greatly reduced after the primary hydrolysis reaction, thereby reducing the resistance of the anchor stirrer in the secondary hydrolysis reaction kettle during stirring, saving electric energy, and simultaneously, because the improvement of the heat transfer in the secondary hydrolysis reaction kettle, the hydrolysis reaction is quicker and more thorough, the yield of the lactide can be effectively improved finally, in addition, the water evaporated from the processes of the lactic acid prepolymerization unit and the falling film evaporator at the upstream contains a small amount of lactic acid, and the hydrolysis reaction can be catalyzed, so that the hydrolysis reaction of the lactic acid oligomer cracking cyclization substrate does not need to be catalyzed by adding any acid additionally, the process is simplified, the amount of waste water is reduced, and the operation cost is also saved.
Drawings
FIG. 1 is a schematic diagram showing the structure of a hydrolysis reaction apparatus for cleaving a cyclized substrate by a lactic acid oligomer according to the present invention.
In the figure, a 1-second-stage hydrolysis reaction kettle; 2-coil heaters; 3-an overflow weir; 4-a stirrer; 5-feeding pipe; 6-a first-stage converter hydrolysis reactor; 7-1# heating jacket; 8-helical ribbon; 9-a reflux water pump; 10-falling film evaporator; 11-a liquid filter; 12-1# gas-liquid separator; 13-a circulation pump; 14-a first-stage condenser; 15-2# gas-liquid separator; 16-a secondary condenser; 17-3# gas-liquid separator; 18-a vacuum pump; 19-2# heating mantle; 20-a discharge end; 21-a feed end; 22-1# drive motor; 23-a body; 24-a rotating shaft; 25-2# drive motor; 30-a tail gas pipeline; evaporating a water pipeline by a 31-lactic acid prepolymerization process; a 32-lactic acid oligomer cracking cyclization substrate pipeline; 33-waste solid pipeline; 34-hydrolysate line.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in other sequences than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, fig. 1 is a schematic structural diagram of a hydrolysis reaction apparatus for cracking a cyclization substrate by using a lactic acid oligomer, comprising a primary converter hydrolysis reactor 7, a secondary hydrolysis reactor 1, a liquid filter 11, a falling-film evaporator 10 and a vacuum pump 18. The viscous semi-fluid material from the upstream lactic acid oligomer cracking cyclization substrate pipeline 32 enters the first-stage converter hydrolysis reactor 6 through a feeding hole arranged at the feeding end 21 of the first-stage converter hydrolysis reactor 6, and meanwhile, the process distilled water containing a small amount of acidic lactic acid from the lactic acid prepolymerization process distilled water pipeline 31 and the outlet of the reflux water pump 9 is also added into the inlet of the feeding end 21 of the first-stage converter hydrolysis reactor 6.
The lactic acid oligomer cracking cyclization substrate belongs to a polyester compound, and can be subjected to hydrolysis reaction with water under the conditions of a certain temperature and a catalyst. The hydrolysis reaction process starts from the migration of water molecules to the surface of an oligomer, the water molecules gradually diffuse into the periphery of ester bonds or hydrophilic groups, and under the action of catalysts such as acid or alkali in a medium, the ester bonds are broken and form a carboxyl and a hydroxyl with water. The process of hydrolysis and chain scission gradually reduces the polymerization degree of the oligomer, and when the polymerization degree is reduced to a certain degree, the oligomer begins to dissolve to form hydrolysis products such as monomolecular lactic acid and lactic acid oligomer which can be dissolved in lactic acid solution.
After entering a first-stage converter hydrolysis reactor 6, lactic acid oligomer cracking cyclization substrate and water evaporated by the process enter a first-stage converter hydrolysis reactor 6, the lactic acid oligomer cracking cyclization substrate and the water are driven by a screw belt 8 to move forward, a body 23 of the first-stage converter hydrolysis reactor 6 is of a cylindrical structure, a 1# heating sleeve 7 is arranged on the outer side of the body to provide heat for hydrolysis reaction, meanwhile, the rotation of the furnace body 6 can increase the uniformity of heating and promote further mixing and reaction of reaction materials, when the materials move to a discharge port of a discharge end 20 of the first-stage converter hydrolysis reactor 6, the first-stage hydrolysis reaction is completed, the viscosity of the materials is greatly reduced, the acidity of the materials is further increased, meanwhile, a 2# heating sleeve 19 is also arranged on the outer side of the discharge end 20, and the 2# heating sleeve 19 is communicated with the 1# heating sleeve 7 through a pipeline so as to prevent the materials from being solidified and forming blockage.
Then, the reaction materials enter the inlet of the feeding pipeline 5 of the second-stage hydrolysis reaction kettle 1 through the outlet of the discharge end 20 of the first-stage converter hydrolysis reactor 6, the outlet of the feeding pipeline 5 is inserted into the bottom of the second-stage hydrolysis reaction kettle 1, and the reaction materials are discharged at the position close to the bottom surface; the coil heater 2 is positioned below the liquid level of the secondary hydrolysis reaction kettle 1 and provides heat required by the hydrolysis reaction; the overflow weir 3 is provided at the upper portion of the secondary hydrolysis reaction vessel 1, from which the reaction solution overflows out of the reaction vessel, and the height thereof determines the liquid holdup of the secondary hydrolysis reaction vessel 1, that is, the time of the secondary hydrolysis reaction.
After the material is subjected to primary hydrolysis by the primary converter hydrolysis reactor 6, the acidity of the material is further increased along with the generation of lactic acid, the acidity of the material is an important factor influencing the hydrolysis rate of a substrate for cracking and cyclizing lactic acid oligomer, and the rate of hydrolytic cleavage of an ester bond in an alkaline or acidic environment is higher than that in a neutral environment. Therefore, as the hydrolysis process proceeds, the amount of terminal carboxyl groups gradually increases, the hydrolysis rate increases, and the autocatalysis phenomenon occurs in the reaction, so that the secondary hydrolysis reaction kettle 1 does not need to add fresh lactic acid as a catalyst. At the same time, the more fully the water and oligomer are contacted, the more favorable the hydrolysis of the oligomer. In order to realize the full contact of the two phases, aiming at the characteristic that the viscosity of the reaction materials is greatly reduced after the first-stage hydrolysis, the stirrer 4 of the second-stage hydrolysis reaction kettle 1 adopts a common anchor type stirring paddle, so that good mixing performance can be obtained, and the corresponding power consumption is effectively reduced due to the great reduction of the resistance.
After passing through the secondary hydrolysis reaction vessel 1, the hydrolysis reaction of the lactic acid oligomer cracking cyclization substrate is carried out completely, and the effective components in the lactic acid oligomer are hydrolyzed into soluble low molecular weight oligomers such as lactic acid dimer and trimer even if the lactic acid monomer cannot be hydrolyzed completely.
Finally, the reaction material is sent to a liquid filter 11 through an outlet of an overflow weir 3 of the secondary hydrolysis reaction kettle 1, after the unavailable oxidized carbide and the upstream catalyst residue are removed, the reaction material enters a falling film evaporator 10 which is suitable for processing high-viscosity and high-heat-sensitivity materials to carry out vacuum evaporation on the reaction material, the water in the reaction material is removed, and the recyclable lactic acid is obtained, and the main components of the recyclable lactic acid comprise lactic acid, lactic acid dimer, lactic acid trimer and the like.
The process water evaporated by the falling-film evaporator 10 is recovered by two-stage condensation and returned to the first-stage converter hydrolysis reactor 6 again to be used as a hydrolysis reaction raw material. It should be noted that the secondary condenser 16 uses low-temperature refrigerant as refrigerant to prevent easily solidified substances from entering the vacuum pump 18, thereby protecting the vacuum pump 18.
The analysis can show that the hydrolysis reaction device for cracking and cyclizing the substrate by the lactic acid oligomer has the characteristics of ingenious design, small total occupied area, land acquisition saving, engineering investment reduction, energy conservation, simple operation, large load adjustment elasticity, safety, reliability and the like, and can be applied to engineering; and provides a new optimized solution structure for the technical field of polylactic acid production.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.
Claims (6)
1. A hydrolysis reaction device of a lactic acid oligomer cracking cyclization substrate is characterized by comprising a primary converter hydrolysis reactor (6), a secondary hydrolysis reaction kettle (1), a liquid filter (11) and a falling film evaporator (10);
a feed port (21) of the first-stage converter hydrolysis reactor (6) is provided with a feed port, a cracking cyclization substrate pipeline (32), a lactic acid prepolymerization process evaporation water pipeline (31) and an outlet of a reflux water pump (9), a discharge port is formed in a discharge end (20) of the first-stage converter hydrolysis reactor, a feed pipeline (5) of a second-stage hydrolysis reactor (1) is connected, a 2# heating jacket (19) is also arranged on the outer side of the discharge end (20), and the 2# heating jacket (19) is communicated with the 1# heating jacket (7) through a pipeline so as to prevent the materials from being solidified and blocked;
a stirrer (4), a feeding pipe (5), a coil heater (2) and an overflow weir (3) are arranged in the secondary hydrolysis reaction kettle (1); the stirrer (4) is connected with a 2# driving motor (25) to drive the stirrer (4) to rotate and stir; the inlet of the feeding pipe (5) is connected with the outlet of the discharge end (20) of the first-stage converter hydrolysis reactor (6), and the outlet of the feeding pipe is inserted into the bottom of the second-stage hydrolysis reaction kettle (1) and is close to the bottom surface; the coil heater (2) is positioned below the liquid level of the secondary hydrolysis reaction kettle (1) and provides heat for the hydrolysis reaction; the overflow weir (3) is arranged at the upper part of the secondary hydrolysis reaction kettle (1), and the reaction liquid overflows out of the reaction kettle;
the inlet of the liquid filter (11) is connected with the outlet of an overflow weir (3) of the secondary hydrolysis reaction kettle (1), the solid phase outlet of the liquid filter is connected with a waste solid pipeline (33), and the liquid phase outlet of the liquid filter is connected with the upper liquid phase inlet of the falling film evaporator (10);
an outlet at the bottom of the falling-film evaporator (10) is sequentially connected with a No. 1 gas-liquid separator (12) and an inlet of a circulating pump (13), and an outlet pipeline of the circulating pump (13) is divided into two branches which are respectively connected with a liquid phase inlet at the upper part of the falling-film evaporator (10) and a hydrolysate pipeline (34); a gas-phase outlet at the top of the 1# gas-liquid separator (12) is sequentially connected with inlets of a first-stage condenser (14), a 2# gas-liquid separator (15), a second-stage condenser (16), a 3# gas-liquid separator (17) and a vacuum pump (18), and a liquid-phase outlet of the 3# gas-liquid separator (17) is sequentially connected with inlets of the 2# gas-liquid separator (15) and a reflux water pump (9).
2. The hydrolysis reaction device for the cleavage and cyclization substrate of lactic acid oligomer according to claim 1, wherein the body (23) of the first-stage converter hydrolysis reactor (6) is cylindrical, the 1# heating jacket (7) is disposed on the outer side of the first-stage converter hydrolysis reactor, the rotating shaft (24) is disposed along the axial direction of the body (23), the rotating shaft is connected with the 1# driving motor (22), the rotating shaft (24) is driven by the 1# driving motor (22) to further drive the body (23) and the ribbon (8) to rotate, and the ribbon (8) is spirally wound along the axial direction of the central shaft and disposed on the central shaft.
3. The hydrolysis reaction device for the cleavage and cyclization substrate of lactic acid oligomer as claimed in claim 2, wherein the viscosity of the reaction solution in said primary converter hydrolysis reactor (6) is much higher than the viscosity of the reaction solution in said secondary hydrolysis reactor (1), and the fluidity of said reaction solution is driven by a ribbon (8); the viscosity of the reaction liquid in the secondary hydrolysis reaction kettle (1) is far greater than that of the liquid in the falling film evaporator (10), and the stirrer (4) adopts an anchor stirrer suitable for high-viscosity liquid to drive the fluidity of the liquid.
4. The hydrolysis reaction apparatus for the cleavage and cyclization substrate of lactic acid oligomer as claimed in claim 1, wherein said secondary condenser (16) uses a low temperature refrigerant as a refrigerant to prevent easily solidifiable substances from entering into said vacuum pump (18).
5. The hydrolysis reaction apparatus for the cleavage and cyclization substrate of lactic acid oligomer according to claim 1, wherein the reaction product after passing through the first stage converter hydrolysis reactor (6) and the second stage hydrolysis reactor (1) is dehydrated by vacuum evaporation using a falling film evaporator (10) suitable for high viscosity and high heat sensitivity materials.
6. The hydrolysis reaction apparatus for the cleavage and cyclization substrate of lactic acid oligomer according to claim 1, wherein the reaction water injected into the primary converter hydrolysis reactor (6) and the secondary hydrolysis reactor (1) is respectively discharged from the pipeline (31) of the upstream lactic acid prepolymerization unit and the process water discharged from the falling film evaporator (10), and both of them contain a small amount of lactic acid and are acidic.
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| CN202210152309.7A CN114471434A (en) | 2022-02-18 | 2022-02-18 | Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate |
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| CN202210152309.7A CN114471434A (en) | 2022-02-18 | 2022-02-18 | Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate |
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Citations (5)
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| WO2010147088A1 (en) * | 2009-06-19 | 2010-12-23 | 東洋エンジニアリング株式会社 | Process for production of polylactic acid |
| CN102718377A (en) * | 2012-06-21 | 2012-10-10 | 上海同济普兰德生物质能股份有限公司 | Device and method for desanding and disinfecting pretreatment of municipal sludge |
| CN109569477A (en) * | 2018-11-09 | 2019-04-05 | 杨建强 | A kind of Screw Extrusion-autoclave stirring combination type reactor and its application |
| CN111424059A (en) * | 2020-06-08 | 2020-07-17 | 中粮营养健康研究院有限公司 | Method and system for producing high-yield, high-gloss pure lactide by using biological fermentation technology to prepare lactic acid |
| CN217887963U (en) * | 2022-02-18 | 2022-11-25 | 华陆工程科技有限责任公司 | Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate |
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2022
- 2022-02-18 CN CN202210152309.7A patent/CN114471434A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010147088A1 (en) * | 2009-06-19 | 2010-12-23 | 東洋エンジニアリング株式会社 | Process for production of polylactic acid |
| CN102718377A (en) * | 2012-06-21 | 2012-10-10 | 上海同济普兰德生物质能股份有限公司 | Device and method for desanding and disinfecting pretreatment of municipal sludge |
| CN109569477A (en) * | 2018-11-09 | 2019-04-05 | 杨建强 | A kind of Screw Extrusion-autoclave stirring combination type reactor and its application |
| CN111424059A (en) * | 2020-06-08 | 2020-07-17 | 中粮营养健康研究院有限公司 | Method and system for producing high-yield, high-gloss pure lactide by using biological fermentation technology to prepare lactic acid |
| CN217887963U (en) * | 2022-02-18 | 2022-11-25 | 华陆工程科技有限责任公司 | Hydrolysis reaction device for lactic acid oligomer cracking cyclization substrate |
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