CN109553602A - A method of recycling lactide production residue - Google Patents
A method of recycling lactide production residue Download PDFInfo
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- CN109553602A CN109553602A CN201811463581.7A CN201811463581A CN109553602A CN 109553602 A CN109553602 A CN 109553602A CN 201811463581 A CN201811463581 A CN 201811463581A CN 109553602 A CN109553602 A CN 109553602A
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- residue
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- lactide
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D319/10—1,4-Dioxanes; Hydrogenated 1,4-dioxanes
- C07D319/12—1,4-Dioxanes; Hydrogenated 1,4-dioxanes not condensed with other rings
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Abstract
The invention discloses a kind of methods for recycling lactide production residue, are related to chemical field, mainly solve the problems, such as that residue is reluctant in lactide production；Method includes the following steps: 1) residue is crushed；2) mixed acid of inorganic acid or lactic acid or inorganic acid and lactic acid is added in residue powder, pH value is adjusted to 3.4-5.2, it is placed under closed environment, acidolysis 13-18min in the environment of 104-127 DEG C, then pressurization stops reaction after being warming up to 172-186 DEG C of continuation acidolysis 21-28min, obtains semi-finished product regenerant；3) semi-finished product regenerant is decolourized, filtration treatment obtains finished product regenerant；4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.Lead to that raw material availability is low, burns the problem of pollution environment the present invention overcomes previous incineration residue, residue is handled by acidolysis, realizes that raw material, catalyst maximally utilize.
Description
Technical field
The present invention relates to chemical field, specifically a kind of method for recycling lactide production residue.
Background technique
Lactide be synthesis degradable green high molecular material-polylactic acid important intermediate, medicine, electronics, once
The fields such as sex aids, automobile have broad application prospects.One of obstacle of limitation polylactic acid application is excessively high for cost at present, main
Be embodied in lactide preparation, purify it is at high cost, wherein residue cannot comprehensively utilize be the high reason of lactide preparation cost it
One.Major part lactide preparation manufacturer is substantially carried out burning disposal to residue at present, has both caused the wave of raw material, catalyst in this way
Take, increase production cost, while burning the exhaust gas of generation, residue pollution environment.Technique is generally in synthesis of lactide process at present
In, 10% or so residue, predominantly oligomer can be generated, the integrated treatment application to this part residue, to reduce lactide or
Polylactic acid production cost improves the effective rate of utilization of raw material and catalyst, polylactic acid industry development is pushed to be of great significance.
Summary of the invention
The purpose of the present invention is to provide a kind of methods for recycling lactide production residue, to solve above-mentioned background skill
The problem of being proposed in art.
To achieve the above object, the invention provides the following technical scheme:
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) water of 2 times of quality is added in residue powder, the mixed acid of inorganic acid or lactic acid or inorganic acid and lactic acid is added, adjusts
PH value is placed under closed environment, acidolysis 13-18min in the environment of 104-127 DEG C, to 3.4-5.2 then in 0.5MPa condition
Under, stop reaction after being warming up to 172-186 DEG C of continuation acidolysis 21-28min, obtains semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional steps.
As a further solution of the present invention: the inorganic acid is one of sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid or more
Kind.
As the present invention further scheme: the nitric acid that sulfuric acid solution that the sulfuric acid is 45%, nitric acid are 68% is molten
Liquid, the hydrochloric acid solution that hydrochloric acid is 37%.
As the present invention further scheme: the inorganic acid be preferably sulfuric acid and hydrochloric acid by weight 2:3 mixing and
At the mixed acid is the mixed acid that inorganic acid and lactic acid are mixed by weight 2:3.
As further scheme of the invention: residue powder is stirred in acid hemolysis process in the step 2.
As further scheme of the invention: the stirring rate is 80-110rpm.
The method for recycling lactide production residue forms the recycle of residue in lactide production.
Compared with prior art, the beneficial effects of the present invention are:
1. the problem of leading to low raw material availability, burning pollution environment the present invention overcomes previous incineration residue, at acidolysis
Residue is managed, realizes that raw material, catalyst maximally utilize；
2, the present invention realizes recycling for catalyst, reduces catalyst charge in the follow-up process, catalysis is effectively reduced
Cost in terms of agent, further decreases the production cost of lactide or polylactic acid；
3. oligomer molecules are answered by hairs such as acidolysis, transesterifications in residue of the present invention, reduce oligomer molecules in hydrolyzation system,
The dispersion of distribution reduces, and molecular weight uniform, this raw material can shorten the reaction time 20% or so in polycondensation, effectively improve production
Efficiency；
4. the present invention is using technique while realizing that raw material, catalyst maximally utilize, pure, coloration of lactide light etc. is not by shadow
It rings.
Specific embodiment
The technical solution of the patent is explained in further detail With reference to embodiment.
Embodiment 1
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, 45% sulfuric acid solution is added under 80rpm stirring condition, adjusts PH
Value is placed under closed environment, acidolysis 13min is warming up to 172 then under the conditions of 0.5MPa in the environment of 104 DEG C to 3.4
DEG C continue acidolysis 21min after stop reaction, obtain semi-finished product regenerant；
3) semi-finished product regenerant is subjected to decolorization, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.5%, and pure light is 99.45%.
Embodiment 2
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, 68% nitric acid solution is added under 85rpm stirring condition, adjusts PH
Value is placed under closed environment, acidolysis 17min is warming up to 178 then under the conditions of 0.5MPa in the environment of 110 DEG C to 4.2
DEG C continue acidolysis 25min after stop reaction, obtain semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.0%, and pure light is 99.8%.
Embodiment 3
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, inorganic acid solution is added under 105rpm stirring condition, inorganic acid is molten
Liquid is that 45% sulfuric acid solution and 37% hydrochloric acid solution are mixed by weight 2:3, and adjusting pH value to 4.5 is placed under closed environment,
Acidolysis 16min in the environment of 118 DEG C stops instead after being warming up to 180 DEG C of continuation acidolysis 25min then under the conditions of 0.5MPa
It answers, obtains semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.9%, and pure light is 99.5%.
Embodiment 4
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, under 85rpm stirring condition, addition phosphoric acid, adjusting pH value to 5.1,
It is placed under closed environment, acidolysis 15min in the environment of 124 DEG C, then under the conditions of 0.5MPa, is warming up to 186 DEG C of continuation acid
Stop reaction after solving 22min, obtains semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.2%, and pure light is 99.61%.
Embodiment 5
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, 37% hydrochloric acid solution is added under 110rpm stirring condition, adjust
PH value is placed under closed environment, acidolysis 18min is warming up to then under the conditions of 0.5MPa in the environment of 127 DEG C to 5.2
Stop reaction after 186 DEG C of continuation acidolysis 28min, obtains semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.2%, and pure light is 99.7%.
Embodiment 6
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) accurately weigh residue powder 1kg, 2kg water be added, under 110rpm stirring condition, lactic acid is added, adjust pH value to
5.2, be placed under closed environment, acidolysis 18min in the environment of 127 DEG C, then under the conditions of 0.5MPa, be warming up to 186 DEG C after
Stop reaction after continuous acidolysis 28min, obtains semi-finished product regenerant；
3) semi-finished product regenerant is subjected to decolorization, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 97.8%, and pure light is 99.7%.
Embodiment 7
A method of recycling lactide production residue, comprising the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) residue powder 1kg is accurately weighed, 2kg water is added, under 110rpm stirring condition, mixed acid is added, and (mixed acid is nothing
Machine acid quality is mixed with lactic acid 2:3 in mass ratio, inorganic acid solution be 45% sulfuric acid solution and 37% hydrochloric acid solution by weight
Mixed than 2:3), pH value is adjusted to 5.2, is placed under closed environment, then acidolysis 18min in the environment of 127 DEG C exists
Under the conditions of 0.5MPa, stops reaction after being warming up to 186 DEG C of continuation acidolysis 28min, obtain semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation according to conventional preparation step.
5) lactide yield is 98.0%, and pure light is 99.55%.
The problem of leading to low raw material availability, burning pollution environment the present invention overcomes previous incineration residue, pass through acidolysis
Residue is handled, realizes maximally utilizing for raw material；The present invention realizes recycling for catalyst, reduces urge in the follow-up process
Catalyst use cost is effectively reduced in agent additional amount, further decreases the production cost of lactide or polylactic acid；The present invention is residual
Oligomer molecules are answered by hairs such as acidolysis, transesterifications in slag, reduce oligomer molecules in hydrolyzation system, and the dispersion of distribution reduces,
Molecular weight uniform, this raw material can shorten the reaction time 20% or so in polycondensation, effectively improve production efficiency；The present invention adopts
With technique while realizing that raw material, catalyst maximally utilize, pure, coloration of lactide light etc. is unaffected.
It is obvious to a person skilled in the art that invention is not limited to the details of the above exemplary embodiments, Er Qie
In the case where without departing substantially from spirit or essential attributes of the invention, the present invention can be realized in other specific forms.Therefore, no matter
From the point of view of which point, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention is by appended power
Benefit requires rather than above description limits, it is intended that all by what is fallen within the meaning and scope of the equivalent elements of the claims
Variation is included within the present invention.
In addition, it should be understood that although this specification is described in terms of embodiments, but not each embodiment is only wrapped
Containing an independent technical solution, this description of the specification is merely for the sake of clarity, and those skilled in the art should
It considers the specification as a whole, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art
The other embodiments being understood that.
Claims (8)
1. a kind of method for recycling lactide production residue, which comprises the following steps:
1) residue generated during synthesis of lactide is dried, crushes, sieves with 100 mesh sieve, obtain residue powder；
2) water of 2 times of quality is added in residue powder, the mixed acid of inorganic acid or lactic acid or inorganic acid and lactic acid is added, adjusts
PH value is placed under closed environment, acidolysis 13-18min in the environment of 104-127 DEG C, then pressurization is warming up to 3.4-5.2
Stop reaction after 172-186 DEG C of continuation acidolysis 21-28min, obtains semi-finished product regenerant；
3) semi-finished product regenerant is decolourized, filtration treatment, obtains finished product regenerant；
4) finished product regenerant is continued on for into lactide preparation.
2. the method according to claim 1 for recycling lactide production residue, it is characterised in that: nothing described in step 2
Machine acid is one of sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid or a variety of.
3. the method according to claim 2 for recycling lactide production residue, it is characterised in that: institute described in step 2
Stating inorganic acid is preferably that sulfuric acid and hydrochloric acid are mixed by weight 2:3, the mixed acid be inorganic acid and lactic acid by weight
2:3 is mixed.
4. the method according to claim 1 for recycling lactide production residue, it is characterised in that: described in step 2
Residue powder is stirred in acid hemolysis process.
5. the method according to claim 1 for recycling lactide production residue, it is characterised in that: described in step 2
Pressurization heating, pressure 0.5MPa.
6. according to the method for recycling lactide production residue described in claim 2-3, it is characterised in that: the sulfuric acid
For 45% sulfuric acid solution, nitric acid be 68% nitric acid solution, hydrochloric acid be 37% hydrochloric acid solution.
7. the method according to claim 4 for recycling lactide production residue, it is characterised in that: the acidolysis
The stirring rate that journey is stirred is 80-110rpm.
8. the method as claimed in claim 1 for recycling lactide production residue, it is characterised in that: this method is used
The recycle of residue is formed in lactide production.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201811463581.7A CN109553602A (en) | 2018-12-03 | 2018-12-03 | A method of recycling lactide production residue |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201811463581.7A CN109553602A (en) | 2018-12-03 | 2018-12-03 | A method of recycling lactide production residue |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IE912435A1 (en) * | 1990-07-13 | 1992-01-15 | Du Pont | High yield recycle process for lactide |
| CN106831700A (en) * | 2017-03-28 | 2017-06-13 | 南京大学 | A kind of method of full green sealing circulation technology production optical voidness L/D lactides |
| CN107501537A (en) * | 2017-09-21 | 2017-12-22 | 南京大学 | It is a kind of to produce second, the process of lactide by-product polymerizing thing residue recycling |
| CN108602794A (en) * | 2016-01-29 | 2018-09-28 | 东洋制罐株式会社 | The recovery method of lactide |
-
2018
- 2018-12-03 CN CN201811463581.7A patent/CN109553602A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IE912435A1 (en) * | 1990-07-13 | 1992-01-15 | Du Pont | High yield recycle process for lactide |
| CN1058210A (en) * | 1990-07-13 | 1992-01-29 | 纳幕尔杜邦公司 | The high yield recycle process that is used for lactide production |
| CN108602794A (en) * | 2016-01-29 | 2018-09-28 | 东洋制罐株式会社 | The recovery method of lactide |
| CN106831700A (en) * | 2017-03-28 | 2017-06-13 | 南京大学 | A kind of method of full green sealing circulation technology production optical voidness L/D lactides |
| CN107501537A (en) * | 2017-09-21 | 2017-12-22 | 南京大学 | It is a kind of to produce second, the process of lactide by-product polymerizing thing residue recycling |
Non-Patent Citations (2)
| Title |
|---|
| 石梁萍 等: "乳酸低聚物水解料合成丙交酯", 《重庆大学学报(自然科学版)》 * |
| 魏顺安 等: "乳酸合成丙交酯反应底物的水解处理", 《化学工业与工程》 * |
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Application publication date: 20190402 |