A kind of production unit of crystalline L-lactic acid and utilize described production unit to produce the method for crystalline L-lactic acid
Technical field
The present invention relates to a kind of lactic acid production unit and lactic acid production method, particularly a kind of crystalline L-lactic acid production unit and utilize described production unit to produce the production method of crystalline L-lactic acid.
Background technology
Lactic acid is take agricultural byproducts as raw material, through microbial fermentation, extracts and a kind of organic acid of making, is widely used in the numerous areas such as food, beverage, medicine, healthcare products, chemical industry, degradable plastics.Therefore lactic acid have enantiomerism owing to containing a unsymmetrical carbon in molecular structure, has two kinds of L-type and D-ALPHA-Hydroxypropionic acids.Pfansteihl is left-handed, D-ALPHA-Hydroxypropionic acid is dextrorotation, DL-LACTIC ACID is racemize, because D-ALPHA-Hydroxypropionic acid can not be absorbed by human body and animal body, intake is crossed at most can cause metabolism disorder, but and Pfansteihl participant and animal body eubolism can be used as good medical material and foodstuff additive, therefore, China recent years is attached most importance to the research and development of Pfansteihl always.
For crystal lactic acid, find after deliberation, the indices such as its optical purity of products, chemical purity are all high than the lactic acid liquid before crystallization, the patent No. is that 03818553.9 patent discloses encapsulated crystalline lactic acid, Preparation Method And The Use, this patent is mainly carries out encapsulate to crystal lactic acid, does not disclose the production technology of crystal lactic acid; And crystal lactic acid than directly more can keep flavour of food products with lactic acid liquid as foodstuff additive.At present, in prior art not stably manufactured Technology and the production unit of crystalline L-lactic acid come forth, namely do not have the enterprise of large-scale production to carry out the suitability for industrialized production of crystalline L-lactic acid; Only have the production method in laboratory to produce crystalline L-lactic acid, specifically adopt concentration and evaporation that the Pfansteihl content in solution is reached more than 85%, under low temperature, spontaneous nucleation or interpolation seeded crystallization, realize solid-liquid separation with filter flask at last.
Summary of the invention
Technical problem to be solved by this invention is: a kind of production unit of suitability for industrialized production crystalline L-lactic acid is provided, and a kind of production method of utilizing described production unit suitability for industrialized production crystalline L-lactic acid is provided.
the present invention is achieved through the following technical solutions: a kind of production unit of crystalline L-lactic acid, described production unit comprises concentration evaporator, the Pfansteihl storage tank, the sour water tank, crystallizer, gas blower and the ion-exchange unit that is connected with Pfansteihl solution feed pipeline, described ion-exchange unit is connected with described concentration evaporator by the first pipeline, be connected by second pipe between described concentration evaporator and described sour water tank, described concentration evaporator is connected by the 3rd pipeline with described Pfansteihl storage tank, described Pfansteihl storage tank is connected with described crystallizer by described the 5th pipeline, described gas blower is connected with described crystallizer by the 7th pipeline, be provided with water recirculator and crystal seed on described crystallizer and add pipeline, the below of the feed opening of described crystallizer is provided with solid-liquid separator.
The production unit of above-mentioned crystalline L-lactic acid, described sour water tank is connected with described crystallizer by the 4th pipeline.
The production unit of above-mentioned crystalline L-lactic acid, described solid-liquid separator by the 6th pipeline respectively with described ion-exchange unit be connected concentration evaporator and be connected.
A kind of method of utilizing above-mentioned production unit to produce crystalline L-lactic acid comprises the steps:
(a) raw material is prepared: Pfansteihl solution;
(b) removal of impurities: the Pfansteihl solution feed pipeline of Pfansteihl solution through being connected with ion-exchange unit enters described ion-exchange unit and carries out the ion-exchange removal of impurities;
(c) concentration and evaporation: first pipeline of the Pfansteihl solution after removal of impurities through connecting described ion-exchange unit and concentration evaporator enters described concentration evaporator and carries out concentration and evaporation;
(d) vapor condensation: the second pipe of the steam that produces in described concentration evaporator through connecting described concentration evaporator and sour water tank enters the condensation of described sour water tank;
(e) regulate concentration: three pipeline of Pfansteihl solution through connecting described concentration evaporator and Pfansteihl storage tank after concentrated enters in described Pfansteihl storage tank, and adjusting Pfansteihl concentration is 85~99% in described Pfansteihl storage tank;
(f) crystallization: five pipeline of Pfansteihl solution through connecting described Pfansteihl storage tank and crystallizer that mixes up concentration in described Pfansteihl storage tank pumps in described crystallizer, keeping the temperature in described crystallizer by the water recirculator that arranges on described crystallizer is 0-20 ℃, and add crystal seed by the crystal seed interpolation pipeline that is arranged on described crystallizer in described crystallizer, then utilize gas blower to be blown into air by pipeline in described crystallizer, kept 4~8 hours;
(g) solid-liquid separation: the feed opening that passes through described crystallizer of the interior crystalline L-lactic acid of described crystallizer and mother liquor enters solid-liquid separator and carries out solid-liquid separation.
Aforesaid method, in step (a), the mass percent concentration of described Pfansteihl solution is 10~22%.
Aforesaid method, in step (f), the quality that adds crystal seed in the described crystallizer be in crystallizer the Pfansteihl solution quality 0.1~0.5%.
Aforesaid method in step (f), blew primary air every 5-10 minute in the described crystallizer of clockwise, and in described crystallizer, the air-blowing quantity of Pfansteihl solution per ton is 10-50m
3/ h, each time of blowing is 30-60 second.
Aforesaid method, in step (g), described sour water tank inner condensat liquid enters described crystallizer by described the 4th pipeline that connects described sour water tank and described crystallizer, rinses crystalline L-lactic acid remaining in described crystallizer.
Aforesaid method, the mother liquor that obtains after solid-liquid separator in step (g) enters described concentration evaporator or enters described ion-exchange unit by the 6th pipeline.
The production unit of crystalline L-lactic acid of the present invention and the method for utilizing described production unit to produce crystalline L-lactic acid have following useful technique effect: utilize the production unit of crystalline L-lactic acid of the present invention can realize the suitability for industrialized production of crystalline L-lactic acid, the crystal lactic acid of producing can carry out encapsulate and make encapsulate crystal lactic acid, but also cryopreservation direct marketing, all indexs such as the optical purity of crystal lactic acid and chemical purity all will be higher than the lactic acid liquid before crystallization, and its range of application also can be wider.And the method for utilizing the production unit of crystalline L-lactic acid of the present invention and utilizing described production unit to produce crystalline L-lactic acid is produced crystalline L-lactic acid, process stabilizing, and sour water, mother liquor all obtained recycle, the powerlessness waste, and production efficiency is high.
Description of drawings
Fig. 1 is the structural representation of the production unit of crystalline L-lactic acid of the present invention.
1-L-lactic acid solution feed pipe, 2-ion-exchange unit, 3-the first pipeline, the 4-concentration evaporator, 5-the 3rd pipeline, 6-second pipe, 7-L-lactic acid storage tank, 8-sour water tank, 9-the 5th pipeline, 10-the 4th pipeline, 11-crystallizer, 12-water recirculator, the 13-crystal seed adds pipeline, 14-the 7th pipeline, 15-gas blower, the 16-feed opening, 17-solid-liquid separator, 18-the 6th pipeline.
Embodiment
Embodiment 1
the production unit of the present embodiment crystalline L-lactic acid comprises concentration evaporator 4, Pfansteihl storage tank 7, sour water tank 8, crystallizer 11, gas blower 15 and the ion-exchange unit 2 that is connected with Pfansteihl solution feed pipeline 1, described ion-exchange unit 2 is connected with described concentration evaporator 4 by the first pipeline 3, be connected by second pipe 6 between described concentration evaporator 4 and described sour water tank 8, described concentration evaporator 4 is connected by the 3rd pipeline 5 with described Pfansteihl storage tank 7, described Pfansteihl storage tank 7 is connected with described crystallizer 11 by described the 5th pipeline 9, described gas blower 15 is connected with described crystallizer 11 by the 7th pipeline 14, be provided with water recirculator 12 and crystal seed on described crystallizer 11 and add pipeline 13, the below of the feed opening 16 of described crystallizer 11 is provided with solid-liquid separator 17.Described sour water tank 8 is connected with described crystallizer 11 by the 4th pipeline 10, makes the condensation sour water in described sour water tank 8 to enter in described crystallizer 11 to rinse undischarged crystal in described crystallizer 11 by described the 4th pipeline 10.Described solid-liquid separator 17 by the 6th pipeline 18 respectively with described ion-exchange unit 2 be connected concentration evaporator 4 and be connected, continue evaporation concentration so that the liquid that obtains after solid-liquid separation can return in described concentration evaporator 4, the impurity in the liquid of perhaps treating to obtain after solid-liquid separation passes into described ion-exchange unit 2 removal of impurities with liquid in the time of more.
Embodiment 2
The method that the present embodiment utilizes the described production unit of embodiment 1 to produce crystalline L-lactic acid comprises the steps:
(a) raw material is prepared: 10~22% Pfansteihl solution;
(b) removal of impurities: the Pfansteihl solution feed pipeline 1 of 10~22% Pfansteihl solution through being connected with ion-exchange unit 2 enters described ion-exchange unit 2 and carries out the ion-exchange removal of impurities, to remove iron ion and the sulfate ion in Pfansteihl solution, remove simultaneously trace sugar, albumen and macromole impurity, known ion exchange resin;
(c) concentration and evaporation: first pipeline 3 of the Pfansteihl solution after removal of impurities through connecting described ion-exchange unit 2 and concentration evaporator 4 enters described concentration evaporator 4 and carries out concentration and evaporation, adopts triple effect or quadruple effect falling-film evaporator;
(d) vapor condensation: the second pipe 6 of the steam that produces in described concentration evaporator 4 through connecting described concentration evaporator 4 and sour water tank 8 enters described sour water tank 8 condensations;
(e) regulate concentration: three pipeline 5 of the Pfansteihl solution after concentrated through connecting described concentration evaporator 4 and Pfansteihl storage tank 7 enters in described Pfansteihl storage tank 7, and be 85~99% in the interior adjusting Pfansteihl of described Pfansteihl storage tank 7 concentration, when from described concentration evaporator 4 Pfansteihl strength of solution out lower than 85% the time, can again import Pfansteihl solution in described concentration evaporator 4 and continue evaporation concentration, perhaps add crystalline L-lactic acid to make the interior Pfansteihl strength of solution of described Pfansteihl storage tank 7 greater than 85 percent in described Pfansteihl storage tank 7, to utilize the carrying out of crystallization,
(f) crystallization: five pipeline 9 of Pfansteihl solution through connecting described Pfansteihl storage tank 7 and crystallizer 11 that mixes up concentration in described Pfansteihl storage tank 7 pumps in described crystallizer 11, keeps the interior temperature of described crystallizers 11 less than or equal to 0~20 ℃ (in case the water in described crystallizer 11 is icing in sub-zero temperature) by the water recirculator 12 that arranges on described crystallizer 11; And add the crystal seed that pipeline 13 adds Pfansteihl quality in 0.1~0.5% crystallizer in the described crystallizer 11 (crystal seed is more many more is conducive to crystallization although add in theory, adds crystal seed too much can cause crystal seed to waste also by being arranged on crystal seed on described crystallizer 11; Determine by test of many times in practice: what add that the crystal seed of Pfansteihl solution quality in 0.1~0.5% crystallizer not only had been conducive to crystallization carries out but also can not cause the waste of crystal seed smoothly); Utilize gas blower 15 to blow primary air every 5-10 minute in the described crystallizer 11 of clockwise by pipeline 14, the air-blowing quantity of the interior Pfansteihl solution per ton of described crystallizer 11 is 10~50m
3/ h blows 30~60 seconds, in case the macrocrystalline phenomenon is arranged, because ventilation is suitable and stirring action, but has avoided blending the phenomenon of crystal; Blowing from for the first time began to keep crystallization 4~8 hours, and extremely the interior crystal amount of described crystallizer 11 no longer obviously increases.Crystal seed can be to reach with concentration the crystalline L-lactic acid that the lower placement of Pfansteihl solution low temperature (3 ℃-25 ℃) spontaneous nucleation more than 95% obtains; It can be also the crystalline L-lactic acid of production method crystallization output of the present invention.
(g) solid-liquid separation: the feed opening that passes through described crystallizer 11 16 of the interior crystalline L-lactic acid of described crystallizer 11 and mother liquor enters solid-liquid separator 17 and carries out solid-liquid separation; Described sour water tank 8 inner condensat liquids enter described crystallizer 11 by described the 4th pipeline 10 that connects described sour water tank 8 and described crystallizer 11, and rinsing has remaining crystalline L-lactic acid in described crystallizer 11; When just having driven row production into, the mother liquor that obtains after solid-liquid separator 17 separates enters described concentration evaporator 4 concentration and evaporation again by the 6th pipeline 18, and again participate in crystallization, after circulation 2-3 time, inside the mother liquor that solid-liquid separator obtains after separating, impurities accumulation is many, can affect crystallization, isolated mother liquor entered described ion-exchange unit 2 by the 6th pipeline 18 and carried out ion-exchange this moment, and then the participation crystallization.