CN114748884A - Lactate reaction rectification apparatus for producing - Google Patents
Lactate reaction rectification apparatus for producing Download PDFInfo
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- CN114748884A CN114748884A CN202210490884.8A CN202210490884A CN114748884A CN 114748884 A CN114748884 A CN 114748884A CN 202210490884 A CN202210490884 A CN 202210490884A CN 114748884 A CN114748884 A CN 114748884A
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- 238000006243 chemical reaction Methods 0.000 title claims abstract description 104
- JVTAAEKCZFNVCJ-UHFFFAOYSA-M Lactate Chemical compound CC(O)C([O-])=O JVTAAEKCZFNVCJ-UHFFFAOYSA-M 0.000 title claims abstract description 50
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 claims abstract description 514
- 239000004310 lactic acid Substances 0.000 claims abstract description 257
- 235000014655 lactic acid Nutrition 0.000 claims abstract description 257
- 238000005886 esterification reaction Methods 0.000 claims abstract description 121
- 230000032050 esterification Effects 0.000 claims abstract description 117
- 238000006297 dehydration reaction Methods 0.000 claims abstract description 96
- 230000018044 dehydration Effects 0.000 claims abstract description 95
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 40
- 229920000747 poly(lactic acid) Polymers 0.000 claims abstract description 36
- 239000004626 polylactic acid Substances 0.000 claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 claims abstract description 17
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 15
- 238000000066 reactive distillation Methods 0.000 claims abstract description 12
- 239000003054 catalyst Substances 0.000 claims description 35
- 238000012856 packing Methods 0.000 claims description 22
- 238000010992 reflux Methods 0.000 claims description 19
- 150000003903 lactic acid esters Chemical class 0.000 claims description 18
- 230000003197 catalytic effect Effects 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 10
- 239000002253 acid Substances 0.000 claims description 8
- 238000011049 filling Methods 0.000 claims description 7
- 239000002994 raw material Substances 0.000 claims description 7
- 239000011949 solid catalyst Substances 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 4
- 239000000376 reactant Substances 0.000 claims description 3
- 238000005265 energy consumption Methods 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 31
- 239000000047 product Substances 0.000 description 28
- LZCLXQDLBQLTDK-UHFFFAOYSA-N ethyl 2-hydroxypropanoate Chemical compound CCOC(=O)C(C)O LZCLXQDLBQLTDK-UHFFFAOYSA-N 0.000 description 18
- 239000012043 crude product Substances 0.000 description 11
- 238000011068 loading method Methods 0.000 description 10
- 229940116333 ethyl lactate Drugs 0.000 description 9
- 239000007791 liquid phase Substances 0.000 description 9
- 239000012071 phase Substances 0.000 description 9
- 239000000945 filler Substances 0.000 description 8
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 238000006136 alcoholysis reaction Methods 0.000 description 6
- -1 rare earth compounds Chemical class 0.000 description 5
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 3
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical compound CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- 239000003729 cation exchange resin Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 238000005373 pervaporation Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- UUFQTNFCRMXOAE-UHFFFAOYSA-N 1-methylmethylene Chemical group C[CH] UUFQTNFCRMXOAE-UHFFFAOYSA-N 0.000 description 1
- IJNJKUQUBKCPPH-UHFFFAOYSA-N 2-hydroxypropanoic acid;propan-2-ol Chemical compound CC(C)O.CC(O)C(O)=O IJNJKUQUBKCPPH-UHFFFAOYSA-N 0.000 description 1
- LPEKGGXMPWTOCB-UHFFFAOYSA-N 8beta-(2,3-epoxy-2-methylbutyryloxy)-14-acetoxytithifolin Natural products COC(=O)C(C)O LPEKGGXMPWTOCB-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 206010007269 Carcinogenicity Diseases 0.000 description 1
- 239000003377 acid catalyst Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000007670 carcinogenicity Effects 0.000 description 1
- 231100000260 carcinogenicity Toxicity 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- ODQWQRRAPPTVAG-GZTJUZNOSA-N doxepin Chemical compound C1OC2=CC=CC=C2C(=C/CCN(C)C)/C2=CC=CC=C21 ODQWQRRAPPTVAG-GZTJUZNOSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001507 metal halide Inorganic materials 0.000 description 1
- 150000005309 metal halides Chemical class 0.000 description 1
- 229940057867 methyl lactate Drugs 0.000 description 1
- ILVGAIQLOCKNQA-UHFFFAOYSA-N propyl 2-hydroxypropanoate Chemical compound CCCOC(=O)C(C)O ILVGAIQLOCKNQA-UHFFFAOYSA-N 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/009—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping in combination with chemical reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/26—Fractionating columns in which vapour and liquid flow past each other, or in which the fluid is sprayed into the vapour, or in which a two-phase mixture is passed in one direction
- B01D3/28—Fractionating columns with surface contact and vertical guides, e.g. film action
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/32—Other features of fractionating columns ; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/32—Other features of fractionating columns ; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30
- B01D3/324—Tray constructions
-
- 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
- B01J19/0053—Details of the reactor
-
- 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
- B01J19/24—Stationary reactors without moving elements inside
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a reactive distillation production device of lactate, which mainly comprises two reactive distillation towers, namely a lactic acid esterification tower and a lactic acid dehydration tower; wherein the low-carbon alcohol feed port is arranged at the bottom of the reaction section of the lactic acid esterification tower, the lactic acid feed port is arranged at the upper part of the reaction section of the lactic acid dehydration tower, the circulating polylactic acid feed port is arranged at the top of the reaction section of the lactic acid esterification tower, the top of the lactic acid dehydration tower is provided with a produced water pipeline, and the bottom of the lactic acid dehydration tower is provided with a produced circulating polylactic acid pipeline; high-purity lactate products are obtained at the top of the lactic acid esterification tower, excessive lactic acid and polylactic acid obtained at the bottom of the lactic acid esterification tower enter a lactic acid dehydration tower, product water is obtained at the top of the lactic acid dehydration tower, and the polylactic acid obtained at the bottom of the lactic acid dehydration tower returns to the lactic acid esterification tower. After the polylactic acid and the low-carbon alcohol pass through the two reaction rectification devices, the mass fraction of the lactate product is as high as more than 98.5%, the product yield is more than 99%, and the energy consumption is greatly reduced.
Description
Technical Field
The invention relates to the technical field of synthesis of chemical lactate in the chemical field, in particular to a high-efficiency energy-saving lactate reaction rectification production device, which is a device for producing lactate by utilizing a reaction rectification technology after lactic acid raw materials are dehydrated.
Background
Organic solvents such as benzene, carbon tetrachloride, chloroform and the like commonly used in the traditional process have certain toxicity and carcinogenicity, and due to the stricter environmental protection requirements in recent years, the search for safe, green and efficient alternative solvents becomes the urgent need of chemical production. Among them, the lactate products such as ethyl lactate have the advantages of biodegradability, innocuity, harmlessness, economy, safety and the like, and are one of the most promising green solvents.
The structure of the lactate is CH3CH (OH) COO-R, wherein R includes but is not limited to lower alcohols such as methanol, ethanol, n-propanol, isopropanol and the like. Is miscible with water, can be dissolved in organic solvents such as alcohol, aromatic hydrocarbon, ester, hydrocarbon, oil and the like, and is generally obtained by esterifying lactic acid and lower alcohol under the catalysis of strong acid.
The main raw materials for synthesizing the lactate are lactic acid and low-carbon alcohols, and most of the traditional synthesis processes adopt a kettle reactor under a vacuum condition, concentrated sulfuric acid is used as a catalyst, and benzene or toluene is required to be added as a water-carrying agent, so that the problems of complex flow, more byproducts, low product purity, serious equipment corrosion and the like exist. In recent years, scientific researchers at home and abroad successively develop a series of solid catalysts for esterification reaction, such as metal halides, rare earth compounds, strong acid ion resin and the like, and the novel solid catalysts overcome the defects of liquid-phase strong acid catalysts to a certain extent and simultaneously improve the feasibility of the catalytic rectification technology in the synthesis production process of lactate. The solid catalyst filling mode is a key technical problem influencing the catalyst efficiency, and the catalytic rectification regular packing is an efficient catalyst filling mode.
In patent CN 112552168A, lactide and ethanol react under the catalysis of strong acid type cation exchange resin to generate ethyl lactate, an azeotrope of ethyl lactate and water is obtained at the top of a catalytic rectification tower, after phase splitting, the obtained crude ester is further separated, an ethyl lactate product is extracted at the bottom of a refining tower, and the top material is recycled to the catalytic rectification tower. In the process, water and ethyl lactate are mainly contained in the top of the refining tower and are circulated back to the catalytic rectifying tower to be unfavorable for the reaction of lactide and ethanol, so that the conversion rate of raw materials of lactide and ethanol is reduced.
The patent CN 109438228A utilizes lactic acid and ethanol to stir, heat and pressurize under the catalysis of concentrated sulfuric acid to carry out esterification reaction, after the mixed steam of ethanol, water and a small amount of ethyl lactate output by the esterification reaction is fractionated by a fractionating tower, the mixed steam of ethanol and water is input into a pervaporation membrane to carry out water separation, the separated ethanol steam is output out of the pervaporation membrane, after being pressurized again, the mixed steam is added into esterification reaction liquid to continuously participate in the reaction, the esterification liquid obtained after the reaction is cooled, and excessive ethanol is distilled out by normal pressure distillation for recycling; ethyl lactate was distilled off under reduced pressure. The method is an intermittent production flow, the flow is complex and the operation is more complicated, the used catalyst is concentrated sulfuric acid, and more side reactions exist.
In summary, the production process of the existing lactate ester products generally has the problems of low product yield, complex process, low product concentration and the like.
Disclosure of Invention
According to the defects of the prior art, the invention provides a reaction rectification production device of lactate, and the lactate produced by using the method has the advantages of simple process, high product yield, high lactate purity and the like.
The invention relates to a high-efficiency energy-saving lactate reaction rectification production device, which mainly comprises two reaction rectification towers, namely a lactic acid esterification tower and a lactic acid dehydration tower. The lactic acid esterification tower is used for producing lactate products, and the lactic acid dehydration tower is used for preparing polylactic acid by lactic acid dehydration; wherein the low-carbon alcohol feed port is arranged at the bottom of the reaction section of the lactic acid esterification tower, the lactic acid feed port is arranged at the upper part of the reaction section of the lactic acid dehydration tower, the circulating polylactic acid feed port is arranged at the top of the reaction section of the lactic acid esterification tower, the top of the lactic acid dehydration tower is provided with a produced water pipeline, and the bottom of the lactic acid dehydration tower is provided with a produced circulating polylactic acid pipeline; high-purity lactate products are obtained at the top of the lactic acid esterification tower, excessive lactic acid and polylactic acid obtained at the bottom of the lactic acid esterification tower enter a lactic acid dehydration tower, product water is obtained at the top of the lactic acid dehydration tower, and the polylactic acid obtained at the bottom of the lactic acid dehydration tower returns to the lactic acid esterification tower.
The technical scheme of the invention is as follows:
a reaction rectification production device of lactate mainly comprises two reaction rectification towers, namely a lactic acid esterification tower and a lactic acid dehydration tower; wherein the low-carbon alcohol feeding port is arranged at the bottom of the reaction section of the lactic acid esterification tower, the lactic acid feeding port is arranged at the upper part of the reaction section of the lactic acid dehydration tower, the circulating polylactic acid feeding port is arranged at the top of the reaction section of the lactic acid esterification tower, the top of the lactic acid dehydration tower is provided with a produced water pipeline, and the bottom of the lactic acid dehydration tower is provided with a produced circulating polylactic acid pipeline; high-purity lactate products are obtained at the top of the lactic acid esterification tower, excessive lactic acid and polylactic acid obtained at the bottom of the lactic acid esterification tower enter a lactic acid dehydration tower, product water is obtained at the top of the lactic acid dehydration tower, and the polylactic acid obtained at the bottom of the lactic acid dehydration tower returns to the lactic acid esterification tower.
In the reaction rectification production device for the lactate, the internals of the rectification section of the lactic acid esterification tower and the stripping section of the lactic acid esterification tower are fillers or trays; the internals of the reaction section tower of the lactic acid esterification tower are bundling packing, modular catalytic rectification structured packing or lactic acid esterification tower trays and the like; the rectifying section of the lactic acid dehydrating tower and the stripping section of the lactic acid dehydrating tower are both provided with packing or trays, and the reaction section of the lactic acid dehydrating tower is provided with packing, modular catalytic rectification structured packing or lactic acid dehydrating trays.
The number of the tower plates of the lactic acid esterification tower is 20-50, wherein the number of the tower plates of the rectification section is 5-15, the number of the tower plates of the reaction section is 10-40, and the number of the tower plates of the stripping section is 2-15.
The number of the lactic acid dehydration tower plates is 20-50, wherein the number of the rectification section plates is 5-15, the number of the reaction section plates is 10-40, and the number of the stripping section plates is 2-15.
The operation pressure of the lactic acid esterification tower is 0.02-0.5 atm, and the reflux ratio is 0.1-1.3; the temperature of the top of the tower is 45-70 ℃, the temperature of the bottom of the tower is 100-126 ℃, and the temperature of the reaction section is 70-110 ℃.
The residence time of each theoretical stage of reaction materials in the reaction section of the lactic acid esterification tower is 20-100 seconds, solid catalysts such as macroporous strong acid resin particles and the like are filled in the reaction section, and the filling amount of the catalysts is 0.2-0.6 m3Catalyst/m3A reaction section.
The operation pressure of the lactic acid dehydration tower is 0.02-0.5 atm, and the reflux ratio is 0.5-4; the temperature of the top of the tower is 45-90 ℃, the temperature of the kettle of the tower is 125-140 ℃, and the temperature of the reaction section is 70-120 ℃.
The residence time of each theoretical stage of reaction materials in the reaction section of the lactic acid dehydration tower is 20-100 seconds, solid catalysts such as macroporous strong acid resin particles and the like are filled in the reaction section, and the filling amount of the catalysts is 0.2-0.6 m3Catalyst/m3And (4) a reaction section.
The feeding molar ratio of the raw material low-carbon alcohol to the lactic acid is 1: 1.3-1: 8. The molar ratio of reactant low-carbon alcohol to lactic acid in the reaction section of the lactic acid esterification tower is always less than 0.5.
The invention simplifies the process flow and greatly reduces the energy consumption of production, and is characterized in that the process of combining two reaction rectifying towers is adopted, the reaction sequence is optimized, the high integration of the process is realized through the design and the modification of equipment, meanwhile, strong acid type cation exchange resin is adopted as a catalyst, and the catalyst is filled in a reaction section in a form of catalytic rectification structured packing, so that the catalyst efficiency is improved. According to the method, the conversion rate of the lactic acid esterification is improved by pre-dehydrating the raw material lactic acid, so that the purity of the product extracted from the top of the lactic acid esterification tower is improved; and a subsequent separation process is not needed, so that the energy-saving requirement is further met.
The invention provides a lactate reaction rectification production device which mainly comprises a lactate esterification tower and a lactate dehydration tower, wherein the lactate esterification tower is used for producing lactate products, and the lactate dehydration tower is used for preparing polylactic acid by dehydrating lactic acid; circulating polylactic acid and low-carbon alcohol respectively enter a reaction rectifying region from the top and the bottom of a reaction section of the lactic acid esterification tower, and products of lactic acid and lactate are moved out of the reaction region of the lactic acid esterification tower while carrying out alcoholysis reaction in the reaction rectifying region of the lactic acid esterification tower, so that the reactant low-carbon alcohol is completely converted; fresh lactic acid raw materials and excessive lactic acid and polylactic acid extracted from the tower kettle of the lactic acid esterification tower enter a lactic acid dehydration tower together, a lactic acid dehydration reaction occurs in the lactic acid dehydration tower, and the polylactic acid is obtained from the tower kettle of the lactic acid dehydration tower; the polylactic acid is circulated to the lactic acid esterification tower and fed from the upper part of the reaction section of the lactic acid esterification tower so as to ensure that the molar ratio of the polylactic acid to the low-carbon ester in the reaction section of the tower is at a higher value; finally, the complete conversion of low-carbon alcohol is realized, and a high-purity lactate product can be obtained at the top of the lactic acid esterification tower.
According to the device for producing the lactate by the efficient energy-saving reaction rectification technology, polylactic acid and low-carbon alcohol pass through the two reaction rectification devices, a high-purity lactate product can be obtained at the top of a lactate esterification tower, and the polylactic acid is extracted from the bottom of a lactic acid dehydration tower and circulated to a reaction rectification unit. The invention has the advantages that the mass fraction of the lactate product can reach more than 98.5 percent, the product yield can reach more than 99 percent, and the energy consumption is greatly reduced.
Drawings
FIG. 1 is a schematic diagram of a reactive distillation production apparatus for lactic acid esters
1, a lactic acid esterification tower; 2, a lactic acid dehydration tower; 3, a rectification section of a lactic acid esterification tower; 4, a reaction section of a lactic acid esterification tower; 5, a stripping section of a lactic acid esterification tower; 6, a rectifying section of a lactic acid dehydrating tower; 7, a reaction section of a lactic acid dehydration tower; 8, a stripping section of a lactic acid dehydration tower; 9, a lactic acid ester condenser at the top of the lactic acid esterification tower; 10 a reboiler for a crude product at the bottom of the lactic acid esterification tower; 11 a water condenser at the top of the lactic acid dehydration tower; 12 lactic acid reboiler at the bottom of lactic acid dehydrating tower; 13 low carbon alcohol feed line; 14 polylactic acid feed line; 15, a crude product at the bottom of the lactic acid esterification tower; 16 returning the lactic acid esterification tower to the tower to obtain a liquid-phase crude product; 17 returning the lactic acid esterification tower to the tower to obtain a gas-phase crude product; 18 a raw product line; 19 gas phase lactic acid esters; 20 liquid phase lactic acid esters; 21 refluxing the lactate ester; 22 lactate ester products; 23 a lactic acid feed line; 24, polylactic acid at the bottom of the lactic acid dehydration tower; 25 returning the lactic acid dehydration tower to the liquid phase polylactic acid; 26 returning the lactic acid dehydration tower to the gas phase of lactic acid esters; 27 gas phase water; 28 liquid phase water; 29 refluxing water; 30 distilling off water.
Detailed Description
The invention will be further illustrated with reference to the following application examples and description, without limiting the scope of the invention thereto.
The device is shown in figure 1, and the lactic acid esterification tower (1) consists of a rectification section (3) of the lactic acid esterification tower, a reaction section (4) of the lactic acid esterification tower and a stripping section (5) of the lactic acid esterification tower; the lactic acid dehydration tower (2) consists of a rectification section (6) of the lactic acid dehydration tower, a reaction section (7) of the lactic acid dehydration tower and a stripping section (8) of the lactic acid dehydration tower; the two-tower device comprises a lactic acid esterification tower (1), a lactic acid dehydration tower (2), a lactate ester condenser (9) at the top of the lactic acid esterification tower, a water condenser (11) at the top of the lactic acid dehydration tower, a crude product reboiler (10) at the bottom of the lactic acid esterification tower, a lactic acid reboiler (12) at the bottom of the lactic acid dehydration tower, related feeding pipelines and pipelines for connecting the devices; a polylactic acid (14) feeding pipeline is connected to the top of a reaction section (4) of a lactic acid esterification tower, a low-carbon alcohol (13) feeding pipeline is connected to the bottom of the reaction section (4) of the lactic acid esterification tower, gas-phase lactate (19) at the top of the lactic acid esterification tower (1) is connected with a gas-phase inlet of a lactate condenser (9) at the top of the lactic acid esterification tower through a pipeline, a condensed liquid-phase lactate (20) material extraction pipeline is connected with a liquid-phase outlet of the lactate condenser (9) at the top of the lactic acid esterification tower, meanwhile, one part of reflux lactate (21) at the liquid-phase outlet of a lactate condenser (8) at the top of the lactic acid esterification tower is connected with the top of the lactic acid esterification tower (1) through a pipeline, and the other part of distilled lactate (22) is extracted as a product; the bottom of the lactic acid esterification tower (1) is connected with the inlet of the lactic acid dehydration tower (2) through a crude product extraction (18) pipeline, a lactic acid feed pipeline (23) is connected to the upper part of the reaction section (7) of the lactic acid dehydration tower, the top steam of the lactic acid dehydration tower (2) is connected with the gas phase inlet of the top water condenser (11) of the lactic acid dehydration tower through a gas phase water (27) pipeline, part of the condensed reflux water (28) flows back to the top of the lactic acid dehydration tower (2), the other part of the condensed reflux water (30) is extracted from the top of the lactic acid dehydration tower as a light component, and part of the circulating polylactic acid (14) material of the bottom liquid phase product of the lactic acid dehydration tower (2) is extracted and returned to the top of the reaction section (4) of the lactic acid esterification tower.
The internals of the rectification section (3) and the stripping section (5) of the lactic acid esterification tower can be fillers or trays, and the internals of the reaction section (4) of the lactic acid esterification tower are bundling and packing fillers, modular catalytic rectification regular fillers or lactic acid esterification trays and the like; the rectifying section (6) and the stripping section (8) of the lactic acid dehydrating tower are both filled or tower trays, and the reaction section (7) of the lactic acid dehydrating tower is filled by bundling and packing, modular catalytic rectification structured filling or lactic acid dehydrating tower trays.
Example 1
The method is used for the process of preparing lactate by carrying out alcoholysis on polylactic acid, and comprises a lactic acid esterification tower, a lactic acid dehydration tower, a lactic acid ester condenser at the top of the lactic acid esterification tower, a water condenser at the top of the lactic acid dehydration tower, a crude product reboiler at the bottom of the lactic acid esterification tower and a lactic acid reboiler at the bottom of the lactic acid dehydration tower, wherein the operating pressure of the lactic acid esterification tower is 0.02atm, the reflux ratio is 0.3, the ethanol feeding amount is 1kmol/h, internal components of a rectifying section and a stripping section of the lactic acid esterification tower are all fillers, internal components of a reaction section of the lactic acid esterification tower are packing materials, and the catalyst loading amount is 0.3m3Catalyst/m3The operation pressure of the lactic acid dehydration tower in the reaction section is 0.08atm, the reflux ratio is 0.8, the feeding amount of the lactic acid is 2.0kmol/h, the internal parts of the rectifying section and the stripping section of the lactic acid dehydration tower are all filled, the internal parts of the reaction section tower of the lactic acid dehydration tower are bundled and packed, the loading amount of the catalyst is 0.3m3Catalyst/m3And (4) a reaction section.
After the process, the purity of the main product ethyl lactate can reach 99.5%, and the yield can reach 99.2%.
Example 2
The method is used in the process of preparing lactate by alcoholysis of polylactic acid and the processThe method comprises a lactic acid esterification tower, a lactic acid dehydration tower, a lactate condenser at the top of the lactic acid esterification tower, a water condenser at the top of the lactic acid dehydration tower, a reboiler for crude products at the bottom of the lactic acid esterification tower and a reboiler for lactic acid at the bottom of the lactic acid dehydration tower, wherein the operating pressure of the lactic acid esterification tower is 0.04atm, the reflux ratio is 0.5, the methanol feeding amount is 1kmol/h, internal components of a rectification section of the lactic acid esterification tower and a stripping section of the lactic acid esterification tower are all fillers, internal components of a reaction section of the lactic acid esterification tower are modular catalytic rectification regular fillers, and the catalyst loading amount is 0.2m3Catalyst/m3The operation pressure of the lactic acid dehydration tower in the reaction section is 0.04atm, the reflux ratio is 2, the feeding amount of the lactic acid is 1.3kmol/h, the internals of the rectification section and the stripping section of the lactic acid dehydration tower are all filled, the internals of the reaction section of the lactic acid dehydration tower are modular catalytic rectification regular filled, and the catalyst loading is 0.3m3Catalyst/m3And (4) a reaction section.
After the process, the purity of the main product methyl lactate can reach 99.0%, and the yield can reach 99.0%.
Example 3
The method is used for the process of preparing lactate by carrying out alcoholysis on polylactic acid, and comprises a lactic acid esterification tower, a lactic acid dehydration tower, a lactic acid ester condenser at the top of the lactic acid esterification tower, a water condenser at the top of the lactic acid dehydration tower, a crude product reboiler at the bottom of the lactic acid esterification tower and a lactic acid reboiler at the bottom of the lactic acid dehydration tower, wherein the operating pressure of the lactic acid esterification tower is 0.02atm, the reflux ratio is 1.1, the feeding amount of isopropanol is 1kmol/h, internal components of a rectification section of the lactic acid esterification tower and an internal component of a stripping section of the lactic acid esterification tower are trays, the internal components of the reaction section of the lactic acid esterification tower are modular catalytic rectification regular packing, and the loading amounts of catalysts such as the lactic acid esterification trays and the like are 0.6m3Catalyst/m3The operation pressure of the lactic acid dehydration tower is 0.1atm, the reflux ratio is 3, the lactic acid feeding amount is 4.0kmol/h, the internals of the rectification section of the lactic acid dehydration tower and the stripping section of the lactic acid dehydration tower are all trays, the internals of the reaction section of the lactic acid dehydration tower are lactic acid dehydration trays, the internals of the reaction section of the lactic acid dehydration tower are bundled and packed with packing and modularized catalytic rectification regular packing, the catalyst loading amount is 0.2m3Catalyst and process for preparing same/m3And (4) a reaction section.
After the process, the purity of the main product, namely the lactic acid isopropanol, can reach 99.6 percent, and the yield can reach 99.4 percent.
Example 4
The method is used for the process of preparing lactate by carrying out alcoholysis on polylactic acid, and comprises a lactic acid esterification tower, a lactic acid dehydration tower, a lactic acid ester condenser at the top of the lactic acid esterification tower, a water condenser at the top of the lactic acid dehydration tower, a crude product reboiler at the bottom of the lactic acid esterification tower and a lactic acid reboiler at the bottom of the lactic acid dehydration tower, wherein the operating pressure of the lactic acid esterification tower is 0.1atm, the reflux ratio is 1.3, the ethanol feeding amount is 1kmol/h, internal components of a rectifying section of the lactic acid esterification tower and a stripping section of the lactic acid esterification tower are trays, internal components of a reaction section of the lactic acid esterification tower are modular catalytic rectification structured packing, and the catalyst loading amount is 0.3m3Catalyst/m3The operation pressure of the lactic acid dehydration tower in the reaction section is 0.05atm, the reflux ratio is 4, the lactic acid feeding amount is 5.0kmol/h, the internal parts of the rectification section and the stripping section of the lactic acid dehydration tower are all filled, the internal part of the reaction section of the lactic acid dehydration tower is a lactic acid dehydration tower tray, the catalyst loading capacity is 0.3m3Catalyst/m3And (4) a reaction section.
After the process, the purity of the main product ethyl lactate can reach 99.1%, and the yield can reach 99.2%.
Example 5
The method is used for the process of preparing lactate by carrying out alcoholysis on polylactic acid, and comprises a lactic acid esterification tower, a lactic acid dehydration tower, a lactic acid ester condenser at the top of the lactic acid esterification tower, a water condenser at the top of the lactic acid dehydration tower, a crude product reboiler at the bottom of the lactic acid esterification tower and a lactic acid reboiler at the bottom of the lactic acid dehydration tower, wherein the operating pressure of the lactic acid esterification tower is 0.01atm, the reflux ratio is 0.7, the feeding amount of n-propanol is 1kmol/h, internal components of a rectification section of the lactic acid esterification tower and internal components of a stripping section of the lactic acid esterification tower are all fillers, internal components of a reaction section of the lactic acid esterification tower are packing materials, and the loading amount of a catalyst is 0.5m3Catalyst/m3The operation pressure of the lactic acid dehydration tower in the reaction section is 0.08atm, the reflux ratio is 1.5, and the feeding amount of lactic acid is6.0kmol/h, the internal parts of the rectifying section and the stripping section of the lactic acid dehydrating tower are all trays, the internal part of the reaction section of the lactic acid dehydrating tower is a bundling and packing material, the catalyst loading capacity is 0.6m3Catalyst/m3And (4) a reaction section.
After the process, the purity of the main product propyl lactate can reach 99.6%, and the yield can reach 99.3%.
While the methods and techniques of the present invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations and modifications of the methods and techniques described herein may be practiced without departing from the spirit and scope of the invention. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and content of the invention. The invention belongs to the known technology.
Claims (10)
1. A reaction rectification production device of lactate is characterized in that the device mainly comprises two reaction rectification towers, namely a lactic acid esterification tower and a lactic acid dehydration tower; wherein the low-carbon alcohol feed port is arranged at the bottom of the reaction section of the lactic acid esterification tower, the lactic acid feed port is arranged at the upper part of the reaction section of the lactic acid dehydration tower, the circulating polylactic acid feed port is arranged at the top of the reaction section of the lactic acid esterification tower, the top of the lactic acid dehydration tower is provided with a produced water pipeline, and the bottom of the lactic acid dehydration tower is provided with a produced circulating polylactic acid pipeline; the high-purity lactate product is obtained from the top of the lactic acid esterification tower, the excessive lactic acid and polylactic acid extracted from the bottom of the lactic acid esterification tower enter a lactic acid dehydration tower, the product water is extracted from the top of the lactic acid dehydration tower, and the polylactic acid obtained from the bottom of the lactic acid dehydration tower returns to the lactic acid esterification tower.
2. The reactive distillation production apparatus for lactic acid esters according to claim 1, wherein the internals in the rectifying section of the lactic acid esterification column and the stripping section of the lactic acid esterification column are packing or trays; the internals of the reaction section tower of the lactic acid esterification tower are bundling packing, modular catalytic rectification structured packing or lactic acid esterification tower trays and the like; the rectifying section of the lactic acid dehydrating tower and the stripping section of the lactic acid dehydrating tower are both provided with packing or trays, and the reaction section of the lactic acid dehydrating tower is provided with packing, modular catalytic rectification structured packing or lactic acid dehydrating trays.
3. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the number of plates in the lactic acid esterification column is 20 to 50, and wherein the number of plates in the rectification section is 5 to 15, the number of plates in the reaction section is 10 to 40, and the number of plates in the stripping section is 2 to 15.
4. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the number of the plates in the lactic acid dehydration column is 20 to 50, wherein the number of the plates in the rectification section is 5 to 15, the number of the plates in the reaction section is 10 to 40, and the number of the plates in the stripping section is 2 to 15.
5. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the operating pressure of the lactic acid esterification column is 0.02 to 0.5atm, and the reflux ratio is 0.1 to 1.3; the temperature of the top of the tower is 45-70 ℃, the temperature of the bottom of the tower is 100-126 ℃, and the temperature of the reaction section is 70-110 ℃.
6. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the residence time of the reaction material in each theoretical stage of the reaction section of the lactic acid esterification column is 20 to 100 seconds, the reaction section is filled with a solid catalyst such as macroporous strong acid resin particles, and the filling amount of the catalyst is 0.2 to 0.6m3Catalyst/m3A reaction section.
7. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the operating pressure of the lactic acid dehydration column is 0.02 to 0.5atm, and the reflux ratio is 0.5 to 4; the temperature of the top of the tower is 45-90 ℃, the temperature of the kettle of the tower is 125-140 ℃, and the temperature of the reaction section is 70-120 ℃.
8. Such as rightThe reactive distillation production device of lactate esters according to claim 1, wherein the residence time of the reaction material of each theoretical stage in the reaction section of the lactic acid dehydration tower is 20-100 seconds, the reaction section is filled with solid catalysts such as macroporous strong acid resin particles, and the filling amount of the catalysts is 0.2-0.6 m3Catalyst/m3And (4) a reaction section.
9. The reactive distillation production device of lactate esters according to claim 1, wherein the feed molar ratio of the raw material lower alcohol to lactic acid is 1: 1.3-1: 8.
10. The reactive distillation apparatus for producing lactic acid esters according to claim 1, wherein the molar ratio of the reactant lower alcohol to lactic acid in the reaction zone of the lactic acid esterification column is always less than 0.5.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070203358A1 (en) * | 2006-02-28 | 2007-08-30 | Hendrik Dirkzwager | Process for reactive distillation of a carboxylic acid |
| US20110144378A1 (en) * | 2007-12-05 | 2011-06-16 | Nanjing University | Catalytic reaction-rectification integrated process and specialized device thereof |
| US20130240346A1 (en) * | 2010-10-14 | 2013-09-19 | Nanjing University | Anti-thermosensitization rectification tower and the rectification process thereof for separating thermosensitive natural substances |
| CN110935186A (en) * | 2019-11-12 | 2020-03-31 | 临沂市金沂蒙生物科技有限公司 | Novel heat coupling rectification process in acetate production process |
| CN213050530U (en) * | 2020-08-15 | 2021-04-27 | 天津大学 | High-efficiency energy-saving ethyl lactate reaction rectification production device |
| CN112934148A (en) * | 2019-11-26 | 2021-06-11 | 南京华基塔业有限公司 | Reaction system and method for oligomerization of lactic acid |
-
2022
- 2022-05-07 CN CN202210490884.8A patent/CN114748884B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070203358A1 (en) * | 2006-02-28 | 2007-08-30 | Hendrik Dirkzwager | Process for reactive distillation of a carboxylic acid |
| US20110144378A1 (en) * | 2007-12-05 | 2011-06-16 | Nanjing University | Catalytic reaction-rectification integrated process and specialized device thereof |
| US20130240346A1 (en) * | 2010-10-14 | 2013-09-19 | Nanjing University | Anti-thermosensitization rectification tower and the rectification process thereof for separating thermosensitive natural substances |
| CN110935186A (en) * | 2019-11-12 | 2020-03-31 | 临沂市金沂蒙生物科技有限公司 | Novel heat coupling rectification process in acetate production process |
| CN112934148A (en) * | 2019-11-26 | 2021-06-11 | 南京华基塔业有限公司 | Reaction system and method for oligomerization of lactic acid |
| CN213050530U (en) * | 2020-08-15 | 2021-04-27 | 天津大学 | High-efficiency energy-saving ethyl lactate reaction rectification production device |
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