77results about How to "Easy to centrifuge" patented technology

The invention discloses a preparation method of erlotinib hydrochloride. The method is characterized by taking 3,4-dihydroxybenzaldehyde as a raw material, synthesizing to obtain 6,7-dimethoxyquinazoline-4-one, directly chloridizing to obtain a product, allowing the product to react with meta-ethynylaniline to obtain the erlotinib hydrochloride. The method has mild reaction condition and is applicable to industrialized production.

A process for the extraction and purification of Paclitaxel from a natural source of taxanes, comprising extracting Paclitaxel with an organic solvent from a natural source of taxanes, and treating the raw material with a base or an acid to obtain a biomass by precipitation. The biomass is isolated and dried, and resin and natural pigments are removed. The biomass is then dissolved in acetone and at least one non-polar solvent is added, until a Paclitaxel-enriched oily phase is obtained. The Paclitaxel-enriched oily phase is then treated with a base or an acid to obtain a second biomass, which is recovered by precipitation and dried. A solution of the second biomass in a volatile solvent is chromatographically purified at least once and crystallized.

The invention provides a milk white fructus momordicae extract, fructus momordicae glycoside V and fructus momordicae glycoside of which are respectively larger than or equal to 40 percent and 98 percent. The invention also discloses a preparation method of the extract. Using fresh fructus momordicae as the raw material, the invention is obtained through the water extraction, the concentration, the enzymatic hydrolysis, the macroporous adsorption resin refining, the ion exchange resin decoloration, the concentration and the spray drying. The invention is characterized in that the process parameters of the steps which are suitable for the industrial production are found, the yield and the quality of the fructus momordicae extraction are all obviously improved, and obvious economic benefits and social benefits are obtained.

The invention discloses highly dispersible spherical nano-silver powder and a preparation method thereof. The method comprises the following steps of: mixing PEG and deionized water in a molar ratio of 1 to (0.005-5), and uniformly stirring the obtained solution; then mixing AgNO3 and a glucose solid in the molar ratio of 1 to (0.005-2), then adding the mixture into solution of the PEG, dissolving the mixture, uniformly stirring the obtained solution, and reacting for 3 to 10 hours at the temperature of between 20 and 70 DEG C, wherein the molar ratio of the PEG to the AgNO3 is (400-10) to 1; and then centrifugating and filtering a reaction product, and washing the obtained product with distilled water to obtain the nano-silver particles. The preparation method is simple and easy to operate; the spherical nano-silver powder has the particle size of between 3 and 20nm, and belongs to a nanometer level; silver nano-particles have the advantages of small size, uniform distribution, good stability and strong antibacterial ability; all used solvents are non-toxic; and the spherical nano-silver powder is easy to add into other products.

The invention relates to a method for quickly identifying refuse landfill percolate in the sewage water discharged into a sewage treatment plant, in particular to a method for quickly judging whether percolate is illegally discharged into the sewage treatment plant. The method comprises the following steps: taking residual active sludge in the sewage treatment plant, then carrying out centrifugation on the residual active sludge so as to obtain a supernatant liquid; carrying out filtration on the supernatant liquid by a filter membrane (0.45 mu m) so as to remove suspended matters in the supernatant liquid to obtain a sample; taking a point every 2nm and then carrying out three-dimensional fluorescence spectrum survey on the sample so as to obtain a numerical three-dimensional fluorogram under the conditions that the excitation wavelength is 200 to 500nm, the emission wavelength is 250 to 600nm, the slit width is 5nm, and the scanning speed is 1200nm / min, wherein in case the fluorescence peak of the sample only refers to fulvic acid-lile substances (Ex / Em: 240 / 440nm) and humic acid-like substances (Ex / Em: 330 / 420 nm), but without protein-like substances, the numerical three-dimensional fluorogram shows that the refuse landfill percolate exists in the sewage water discharged into the sewage treatment plant, otherwise, the numerical three-dimensional fluorogram shows that no refuse landfill percolate exists in the sewage water discharged into the sewage treatment plant. The method of the invention has the advantages of simpleness, speediness, less required samples, high sensitivity, low cost, and capability of being widely applicable for quickly judging whether percolate is discharged into a sewage treatment plant.

The invention discloses a preparation method of silicon dioxide@ quantum dot composite nanoparticles. The method comprises steps as follows: thiolation silicon dioxide nanoparticles are prepared firstly, and the silicon dioxide@ quantum dot composite nanoparticles are prepared with a hydrothermal method. The preparation method is simple and easy to implement, high in yield and efficiency and beneficial to large-scale production. The prepared silicon dioxide@ quantum dot composite nanoparticles comprise silicon dioxide balls with particle sizes of 50-800 nm and quantum dot particles loaded on the silicon dioxide balls. The excellent fluorescence property of quantum dots is preserved, centrifugal separation of the particles is facilitated due to the fact that the quantum dots are loaded on silicon dioxide, the aftertreatment steps during use of the quantum dots are greatly optimized and simplified, and the preparation method has a broad application prospect.

The invention discloses an oily sludge recycling and reduction treatment method and system. The treatment method comprises the steps of crushing, fluidization, screening and impurity removal, chemicalhot washing, solid-liquid separation, drying, deep treatment and the like. The treatment system mainly comprises an oily sludge storage tank, a feeding device, an impurity removal system, an oil recovery system and a dehydration system which are connected in sequence, wherein oily sludge in the oily sludge storage tank is conveyed to the impurity removal system through the feeding device to be subjected to crushing, fluidization and screening treatment, then the oil sludge treated by the impurity removal system is conveyed to the oil recovery system to collect crude oil, and isolated slag slurry is conveyed to the dehydration system to be subjected to solid-liquid separation, drying treatment and harmless deep treatment. By adopting the method and the treatment system provided by the invention, more than 80% of mineral oil in the oily sludge can be recycled, and meanwhile, the moisture content in the sludge is reduced to 30% or below, so that recycling and reduction of the oily sludgeare realized.

The invention relates the ultrasonic degumming method, comprising adjusting emulsion, hypersonic auxiliary enzymolysis and hypersonic auxiliary hydrating. The method comprises the following steps: after biological enzyme treatment fat, carrying out low water hydrated phase, carrying out ultra-audio wave radiation, and then carrying out water-oil separating. The invention can shorten treatment time and enzyme content, improves the boundary effect between oil and water, reduces biological enzyme density, advances the gelatinous hydrating, improves detaching efficiency, modifies weight of boil-off gum content, and reduces equipment investment and oil consumption, reduces cost.

The present invention discloses a mung bean protein peptide having ACE inhibitory activity and a preparation method and applications thereof. According to the invention, the preparation method comprises: mixing water and mung bean protein powder to prepare mung bean protein slurry, after the pH of the slurry is adjusted to 3.5-5, adding cellulase for hydrolysis at 45-55 DEG C, after the enzyme hydrolysis, deactivating the cellulose, centrifugating, and washing with water to remove impurities; and then adjusting the pH to be 8-9, adding alkaline protease for hydrolysis at 50-60 DEG C, after the enzyme hydrolysis, deactivating the alkaline protease and obtaining the mung bean protein peptide having ACE inhibitory activity after coarse filtration, fine filtration and nanofiltration, and drying. According to the invention, the preparation method is energy efficient and convenient in operation, product quality and production efficiency are improved, and the obtained protein peptide has the ACE inhibitory activity of 42.8-59.6[mu]g / mL in terms of IC50, and can be widely used as a health food, or materials general food, in particular for the preparation of antihypertensive products assist.

The invention provides a process for preparing potassium chloride by using carnallite containing calcium sulfate. The process comprises the following steps: applying old brine in slurry mixing of calcium sulfate-containing carnallite extracted in a salt pan by using a hydraulic mining or dry mining method, adding a collecting agent used for flotation of calcium sulfate during slurry mixing and carrying out primary reverse flotation on a material obtained after slurry mixing so as to collect calcium sulfate; then adding a collecting agent used for flotation of sodium chloride into the slurry which has undergone flotation of calcium sulfate and carrying out secondary reverse flotation to collect sodium chloride; and carrying out dehalogenation on a product in a tank obtained after flotation of sodium chloride, adding water to decompose a solid phase after dehalogenation and subjecting the decomposed solid phase to condensation, filtration, washing, centrifuge dewatering and drying so as to obtain the potassium chloride product. The production process provided by the invention is simple, is convenient to operate and has strong adaptability to the raw material carnallite; the potassium chloride product prepared by using the process in the invention has the advantages of good quality, coarse granularity, uneasy caking and convenient usage.

The invention discloses a macromolecular covalent organic framework polymer based on a triphenylamine derivative. The polymer has following repeated structural units shown in the description, whereinX represents one of the repeated structural units, the connection positions of the repeated structural units are shown in a structural formula, and repeated structures are repeated 10-20 times. The provided macromolecular covalent organic framework polymer based on the triphenylamine derivative can be used for rapidly and sensitively detecting and effectively removing divalent mercury ions in sewage.

The present invention relates to a clean production method for co-production of ammonium bicarbonate through combination of high purity carbon dioxide and melamine tail gas. According to the clean production method, carbon dioxide gas in a large nitrogen fertilizer device is subjected to decompression; the decompressed carbon dioxide gas and melamine tail gas are subjected to a reaction in a main carbonization tower, wherein the melamine tail gas is subjected to absorption condensation; and then a thickener treatment, centrifugation separation and packaging are performed to obtain an ammonium bicarbonate product, wherein the carbonized dilute mother liquor and the centrifugated waste liquid enter recycling. According to the present invention, high purity carbon dioxide gas is adopted, such that the effective concentration of the carbon dioxide actually participating in the reaction is increased, and production capacity is significantly increased compared with the carbonation equipment having the same size; the dilute mother liquor from the ammonium bicarbonate production is recycled so as to achieve clean production; and the purity of the carbon dioxide gas is high, and the impurity content is significantly reduced so as to easily improve product quality.

A method for evaluating the potential of the complexation of a water-soluble humus matter with heavy metals mainly comprises the steps of (A) extracting and preparing water-soluble organic samples, scanning three-dimensional fluorescence spectrums of the organic samples, deducting background values and then exporting three-dimensional fluorescence data; (B) carrying out parallel factor analysis on the exported three-dimensional fluorescence data on MATLAB by adopting DOMFluor software so as to obtain the number of fluorescence components and the concentration score Fmax of each sample in the corresponding fluorescence component; (C) adding the Fmax of the fluorescence components with the emission wavelength more than 380nm at a fluorescence peak center so as to obtain the concentration score F1 of the water-soluble humus matter, adding the Fmax of the fluorescence components with the emission wavelength more than 420nm at the fluorescence peak center to obtain the score F2, and calculating according to HQ=F2 / F1 to obtain HQ, and judging the potential of complexation of the water-soluble humus matter with heavy metals through the HQ, wherein if the HQ value of the water-soluble humus matter is large, the potential of complexation with heavy metal is high, and if the HQ value of the water-soluble humus matter is small, the potential of complexation with heavy metal is low. According to the method, the calculation is simple, the analysis is quick, and the sensitivity is high.

The invention discloses a stripping agent special for preparing graphene through mechanical stripping and a preparation method. The stripping agent is prepared from, by weight, 25%-35% of composite nanoparticles, 1%-5% of dispersing agent and 60%-74% of deionized water, wherein the preparation method comprises the steps that metal or metallic oxide nano powder is taken as the main body which is wrapped with graphene oxide, amino groups are grafted onto the graphene oxide, and then the composite nanoparticles are formed. By means of the method, the stripping agent special for preparing the graphene through mechanical stripping is provided, the space between graphitic layers can be effectively widened, graphite can be stripped in a pollution-free mode, and agglomeration of the graphene can be prevented.

The invention provides a preparation method of recombination bone morphogenetic protein BMP-2 mature peptide, which comprises deleting the 2-18 amino acid encoding genes of DsbA gene signal peptide, keeping the codon of the first methilanin as starting codon to obtain a section recombined in expression carrier to obtain recombination plasmid 1, recombining the DNA of the bone morphogenetic protein BMP-2 complete mature peptide in the descending of the DsbA gene of recombination plasmid 1 to obtain recombination plasmid 2, transferring the recombination plasmid 2 into the thallus of expression host strain to obtain engineering bacteria, via cultivation and adding inducer to express target gene, breaking bacteria, separating and purifying to obtain DsbA-BMP-2 fusion protein, cutting the DsbA-BMP-2 fusion protein via prolease, separating to obtain the one morphogenetic protein BMP-2 mature peptide. The inventive product has same amino acid sequence of natural BMP-2 mature peptide, to realize soluble cell fusion expression, while the fusion protein can be purified further via Ni2+ affinity chromatography to simplify the purification before BMP-2 renaturation.

The invention relates to micrometer carbon spheres and a preparation method thereof. The preparation method adopts glucose as a carbon source, adopts sodium dodecyl sulfate and / or cetyl trimethyl ammonium bromide as a surfactant, by utilizing the surfactant, vesicae can be formed in an aqueous solution, wherein the micrometer carbon spheres grow and are formed in the vesicae; the particle size ofthe micrometer carbon sphere depends on the size of the vesicae, so that the particle size of the finally generated micrometer carbon spheres can be adjusted by adjusting the surfactant. Compared withthe traditional process, the micrometer carbon spheres are simple in preparation process, high in controllability, good in repetition, pollution-free and environmentally friendly; the preparation method provided by the invention is high in yield, the yield can reach 20 percent or above; the mass production is feasible, and the prepared micrometer carbon spheres are easy to be centrifugally separated; the raw materials are low in cost and easy to obtain; the micrometer carbon spheres prepared by virtue of the method provided by the invention can be widely applied to the fields such as catalystcarriers, medicine transportation, pollutant adsorption, fuel cells, supercapacitors and lithium ion battery electrode materials.

The invention discloses a preparation method of gefitinib. In the method, isovanillin is taken as a raw material and synthesized to obtain 7-methoxy-6-(3-morpholine-propoxy)quinazoline-4-one which is directly chloridized to obtain a product, the product is allowed to react with 3-chlorine-4-fluoroaniline to obtain gefitinib hydrochloride which neutralized off hydrochloric acid to obtain the gefitinib. The method has mild reaction condition and is applicable to industrialized production.

The invention relates to a method for purification of low-purity single-wall carbon nano-tubes. The method provided by the invention can realize purification of low-purity single-wall carbon nano-tubes by atmospheric oxidation, ultrasonic dispersion, centrifugal separation at different speeds, and hydrogen peroxide refluxing. Concretely, the method provided by the invention comprises the following steps of adding single-wall carbon nano-tube products subjected to atmospheric oxidation into a surfactant solution, carrying out ultrasonic dispersion, carrying out low-speed centrifugal separation and high-speed centrifugal separation to remove impurity particles, carrying out pressure filtration of the supernatant obtained by the high-speed centrifugal separation, mixing the filtrate and hydrogen peroxide, carrying out addition refluxing of the mixture, and carrying out vacuum filtration, flushing and drying to obtain the low-purity single-wall carbon nano-tubes. Compared with the prior art, the method provided by the invention avoids that waste liquid pollution is produced because of single utilization of hydrochloric acid in catalyst removal, and realizes removal of a catalyst according to a principle that the increasing of the weight of an oxidized catalyst is conducive to centrifugal separation. In purification, the centrifugal separation is a main process and oxidation adopting a weak oxidant H2O2 is an auxiliary process and thus the damage on a structure of the single-wall carbon nano-tube is small.

The invention discloses a biological medicine extraction process in the technical field of biological medicine extraction, and the process comprises the following specific steps: step 1, taking a proper amount of untreated traditional Chinese medicinal materials and a proper proportion of water; step 2, putting the traditional Chinese medicinal materials into a medicine decocting device, then injecting water into the medicine decocting device, sealing the medicine decocting device, and starting the medicine decocting device; step 3, after the medicine decocting device works for a period of time, taking treated medicine residues out of the medicine decocting device, discharging medicine liquid in the medicine decocting device, and completing extraction of components of the traditional Chinese medicinal materials; and step 4, after extraction of all the traditional Chinese medicinal materials is completed, clearing the medicine decocting device for facilitating follow-up use. A filtering barrel is driven to rotate through a connecting rod, liquid medicine in medicine residues is thrown out of the filtering barrel through centrifugal force, and therefore in the medicine residue fishing process, the residual liquid medicine in the medicine residues can be separated out and reused at the same time, waste of the liquid medicine is avoided, and the extraction efficiency is improved.

The invention provides a method for preparing potassium chloride by using mixed potassic salt ores. The method comprises the following step: firstly crushing the mixed potassic salt ores; then adding the mixed potassic salt ores into a decomposition crystallizer; adding fresh water and circulating saturated E-point liquid into the decomposition crystallizer at the same time, wherein the adding amount of the fresh water is 105%-120% of a theoretical calculating value and the adding amount of the circulating saturated liquid is 2.5-8 times as much as that the adding amount of raw ores; infiltrating a bottom flow of the decomposition crystallizer into grading work to be graded; carrying out ore grinding on a rough grain part and then carrying out flotation; directly carrying out the flotation on a fine grain part; in the flotation process, using the two parts to independently carry out the flotation; carrying out the flotation to obtain concentrate ores, and filtering, washing, dehydrating and drying to obtain a potassium chloride product. The product is good in quality, rough in granularity and relative low in processing cost; the adaptability to the raw ores is very strong; the potassium chloride product produced by the method can be used as an industrial product and can also be used as a farm-oriented potassium fertilizer, so that the application range of the product is widened; the potassium chloride product is rough in granularity and is easy to filter, centrifuge and dehydrate; when the potassium chloride product is dried, the energy consumption is low, so that the production cost of enterprises is reduced.

The invention discloses a synthetic method of pregnenolone acetate. The method comprises the following steps of: 1, carrying out hydrogenation reaction of dehydropregnenolone acetate at a temperature ranging from 35 to 45 DEG C and under 0.4 MPa to 0.8 MPa by taking ethyl acetate as a solvent and a compound catalyst of a palladium / carbon catalyst and ammonium acetate; 2, filtering the reaction liquid after reaction, concentrating the filtrate under normal pressure, then adding a mixed solvent to the concentrated filtrate, and carrying out centrifugal drying after cooling to obtain crude pregnenolone acetate; 3, washing the crude pregnenolone acetate, then carrying out drip washing by using methanol, and drying to obtain white sandy solid pregnenolone acetate. The synthetic method provided by the invention is mild in reaction conditions; ethyl acetate is used as the solvent, and the solvent is high in recovery and low in dosage; as the palladium / carbon catalyst and ammonium acetate are used as the compound catalyst, the catalytic hydrogenation selectivity is high and no impurity is generated; besides, the aftertreatment is simple and the yield is high; the mass purity of the product can be higher than 99.5%.

The invention relates to a separation method of waste polyphenylene sulfide and polytetrafluoroethylene blended dust settling pockets. The separation method comprises the steps that the waste polyphenylene sulfide and polytetrafluoroethylene blended dust settling pockets are firstly smashed, then the smashed mixed materials are added into a separating medium with the density between the density of polyphenylene sulfide and the density of polytetrafluoroethylene for centrifugal separation, blended fabric is smashed according to the different densities of two fibers, and the aim of recycling polyphenylene sulfide and polytetrafluoroethylene in the waste dust settling pockets is achieved through centrifugal separation. The purity of polyphenylene sulfide materials obtained after separation reaches 97% or above, the purity of polytetrafluoroethylene materials reaches 91% or above, the material separation purity is high, the separation effect is good, and the recycling value is high.

The present invention discloses a mung bean protein peptide having ACE inhibitory activity and a preparation method and applications thereof. According to the invention, the preparation method comprises: mixing water and mung bean protein powder to prepare mung bean protein slurry, after the pH of the slurry is adjusted to 3.5-5, adding cellulase for hydrolysis at 45-55 DEG C, after the enzyme hydrolysis, deactivating the cellulose, centrifugating, and washing with water to remove impurities; and then adjusting the pH to be 8-9, adding alkaline protease for hydrolysis at 50-60 DEG C, after the enzyme hydrolysis, deactivating the alkaline protease and obtaining the mung bean protein peptide having ACE inhibitory activity after coarse filtration, fine filtration and nanofiltration, and drying. According to the invention, the preparation method is energy efficient and convenient in operation, product quality and production efficiency are improved, and the obtained protein peptide has the ACE inhibitory activity of 42.8-59.6[mu]g / mL in terms of IC50, and can be widely used as a health food, or materials general food, in particular for the preparation of antihypertensive products assist.

The invention discloses a multi-level double-pore structure composite photocatalyst, preparation and application thereof. The composite photocatalyst consists of a tree-shaped mesoporous SiO2 template, TiO2, Au nanoparticles and a mesoporous SiO2 shell layer. The invention overcomes the defect that conventional TiO2 catalyst can only degrade organic dye molecules in an ultraviolet waveband, effectively broadens the use conditions of TiO2 photocatalyst, and also utilizes the metal-semiconductor synergistic effect to inhibit photoelectron-hole recombination so as to improve the catalytic efficiency; the photocatalyst has a multi-level double-pore structure, greatly improves the openness of a catalytic site while enhancing the loading capacity of a functional element, facilitates the interaction of the photocatalyst and substrate molecules so as to improve the photocatalytic efficiency, meanwhile, the structure can improve the stability of the catalyst, and the catalyst can be repeatedlyand efficiently used, thus avoiding the waste of product.

The invention relates to a water-soluble rare earth nanocrystalline, and application and a preparation method thereof. The preparation method specifically comprises the following steps: mixing an oil-soluble rare earth-based luminescent nanocrystalline stock solution pre-dissolved in trichloromethane with a certain proportion of ethanol and water, then adding an amino diphosphate micromolecular ligand, adjusting the pH value of the water phase to a low pH value (2-3), carrying out stirring, and collecting a supernatant to obtain modified nanocrystalline. The purification mode of the produced nanocrystalline is low-speed centrifugal separation in a neutral aqueous solution, and ultrasonic dispersion is performed in an aqueous solution with a low pH value (4-5); the purified modified productcan be directly coupled with functional molecules activated by succinimide in advance to obtain the nanoprobe with required functions. The nanocrystalline obtained by the functionalization method ishigh in yield, large in amino loading capacity and easy to purify; and the prepared nanoprobe is higher in stability, shows obviously improved efficiency in application based on resonance energy transfer, and has application value in the fields of biomedicine, photovoltaic energy and the like.

The invention provides a light salt brine concentrated mother liquor salt recovery system, and relates to the field of light salt brine concentrated mother liquor salt recovery. A sodium sulfate removal unit comprises a crystallizer and a thickener which are communicated with each other through a pipeline, a light salt brine concentrated mother liquor inlet pipe is communicated with the crystallizer, the chlorate decomposition unit comprises a chlorate decomposition tank and an analysis tower which are communicated with each other through a pipeline, a liquid discharge pipe is arranged on theanalysis tower, and the cooling unit comprises at least one first circulating cooler. Circulating cooling water is introduced into the first circulating cooler, the first circulating cooler is communicated with the crystallizer through a circulating pipeline, the crystallizer is communicated with a light salt brine input pipe, the crystallizer is communicated with the chlorate decomposing tank through a pipeline, and the chlorate decomposing tank is communicated with a hydrochloric acid liquid inlet pipe and a steam pipe. The chlorate decomposition tank and the desorption tower are communicated with a chlorine discharge pipe. According to the invention, the use cost is reduced.

The invention discloses a preparation method of phlebopus portentosus polysaccharide. The preparation method comprises the following steps: inoculating phlebopus portentosus hyphae into a liquid fermentation culture medium, and fermenting to obtain fermentation broth; concentrating the obtained fermentation broth to obtain a concentrated solution; centrifuging the obtained concentrated solution, taking the supernatant, adding ethanol into the supernate, centrifuging, collecting the precipitate, and carrying out freeze drying to obtain crude polysaccharide; preparing a crude polysaccharide solution, eluting the crude polysaccharide solution by using a DEAE-52 cellulose column, and concentrating the eluent to obtain a crude polysaccharide concentrated solution; and loading the obtained crudepolysaccharide concentrated solution into a dialysis bag for dialysis, and freeze-drying the dialysate to obtain the phlebopus portentosus polysaccharide. According to the method, the purity of the phlebopus portentosus polysaccharide is improved, the subsequent research on the structure and composition of the fungal polysaccharide is facilitated, and the development space and way are broadened for the development of the medicinal value of the phlebopus portentosus polysaccharide.

The invention belongs to the technical field of chemical engineering, and particularly relates to a method for recovering an antioxidant 300 in efficient solvent oil mother liquor. The recovery methodof the antioxidant 300 in the efficient solvent oil mother liquor comprises the following steps of: (1) mother liquor concentration: carrying out reduced pressure distillation and concentration on the mother liquor containing the antioxidant 300 to evaporate No.200 solvent oil of which the volume is 30-60% of the total volume of the mother liquor; (2) cooling of the concentrated solution: introducing chilled water into a jacket of a recovery kettle, putting the concentrated solution with the temperature of 130-140 DEG C into the recovery kettle, and stirring until the temperature of the concentrated solution is 50-80 DEG C; (3) crystallization: adding n-hexane accounting for 10%-20% of the volume of the concentrated solution into the recovery kettle, continuously stirring until the temperature is -10 DEG C to -5 DEG C, and then stirring for 2-3 hours; and (4) standing and centrifuging: stopping stirring, standing, and then centrifuging to obtain the antioxidant 300. The method is short in crystallization time, high in recovery efficiency, low in centrifugal difficulty and high in operation safety.

The present invention discloses a bacterium and an obtaining method and application thereof. The bacterium has a property of coproducing 1,3-propanediol and D-lactic acid. Further, the bacterium is Klebsiella oxytoca, including Klebsiella oxytoca PDL-5 CCTCC M 2016185. The obtaining method of the bacterium may be to obtain the bacterium by directly screening wild bacteria that satisfy conditions from the environment or performing gene engineering modification to wild bacteria. The present invention has the advantages that the bacteria can coproduce 1,3-propanediol and D-lactic acid through fermentation, the molar conversion rate and the concentration of the two products are very high, the types of byproducts are few, the concentration is low, the product extraction process is simplified, the high-efficiency biological production of 1,3-propanediol and D-lactic acid can be realized, and the industrial application prospect is very great.