The method of purifying refined fluorene by crystallizing
Technical field
The present invention relates to field of coal tar deep processing, particularly a kind of from coal tar the method for purifying refined fluorene by crystallizing.
Background technology
Fluorenes is a kind of important organic synthesis raw material, can synthesize trinitro-fluorenone, aryl transparent nylon, fluorenes urea formaldehyde etc.; Be used for pharmacy, but synthetic pesticide, weedicide, sterilizing agent, preparation anodyne, hypotensor and spasmolytic etc.; Be used for dyestuff, can synthesize fluorescence dye, vat dyes etc.Because the special construction of fluorenes, it is particularly had many uses in the synthetic resins industry in organic synthesis industry, also can prepare the electron donor of fluorenyl metallic compound, organic photoconductor, resin, dyestuff, Ziegler-Natta catalyst etc.In recent years, by fluorenes synthetic fluorene derivatives more and more widely in the application in fields such as chemical industry, functional high molecule material, polymer synthetic chemistry and biotechnology, heighten to the demand of fluorenes in the domestic and international market, so the extraction process for purification of research fluorenes seems more and more important.
Fluorenes is one of main component in the coal tar, accounts for 1.8%~2.0% in coal tar, is to separate in the coal tar wash oil and utilization product early.The technology of from coal tar, the extracting of domestic present report, refining fluorenes and mainly contain Anshan iron and steel plant technology and bao steel technology.Wherein Anshan iron and steel plant utilizes dimethylbenzene as solvent, by the solution crystallization fluorenes of purifying.Anshan iron and steel plant South Platform Fine Chemical Works was put into serial production till now from nineteen ninety-five, had realized the product of purity 〉=93% and purity 〉=95% two quality grade.Constantly perfect by to the demarcation of operating parameters and technology, the yield of product improves constantly, and to this factory in 2000 yield of raw material is reached 12%.
But the bao steel technology application reference number is 200510026998.3 patent content.Patent proposes, and with non-polar solvent the fluorenes cut is carried out solvent crystallization earlier, mainly goes out non polar impurities, with polar solvent crystal is washed then, removes polar impurity.Compare with the Anshan iron and steel plant technology, the fluorenes product is mentioned more than 25% from 12% the yield of raw material, and the purity of fluorenes has been up to more than 97%.
From above-mentioned prior art as can be seen, the state of the art of domestic extraction fluorenes is still lower, the yield of fluorenes is low, and the technical patent that from application number is 200510026998.3 Baosteel can be found out, if product purity is reached more than 97%, must yield further be reduced through the organic solvent washing operation, production cost of products rises simultaneously.
Summary of the invention
The present invention utilizes the fluorenes in crystallization process purification and the pix carbonis praeparsta, existing crystallization processes process has been proposed important improvement, thereby improved the purity and the yield of fluorenes product significantly, has tangible economic benefit.Because used raw material is the fluorenes enriched fraction that obtains by rectifying from washing oil, the content of fluorenes is 50~90%, and impurity wherein mainly is dibenzofuran and acenaphthene, and wherein fluorenes and acenaphthene are apolar substances, and dibenzofuran is a polar material.Therefore the present invention proposes, at first the fluorenes component is carried out pre-treatment, adopt the blended organic solvent to carry out centrifuge washing, remove most polarity and nonpolar impurity in the raw material, adopt organic solvent fluorenes to be carried out the technical scheme of solvent crystallization and washing crystal then.
Concrete processing step of the present invention is as follows:
(1) pre-treatment: adopting with the mixture of the low-molecular-weight organic solvent of C1-C3 and non-polar organic solvent is that 50~90% fluorenes enriched fraction carries out centrifuge washing with fluorenes content, remove most of organic impurity, the weight ratio of mixed organic solvents and fluorenes cut is 0.3: 1~1.2: 1.
(2) solvent crystallization: the above-mentioned fluorenes cut that obtains is mixed the back 70~90 ℃ of dissolvings fully with organic solvent, it is 0.4: 1~1.2: 1 that organic solvent adds weight ratio, according to the rate of temperature fall of 15~40 ℃/h, system temperature is reduced to 0~25 ℃ then, filter the coarse crystal that obtains fluorenes.
(3) subsequent disposal: adopt the described mixed organic solvents of step (1) that crystal is carried out centrifuge washing, remove attached to the impurity on the plane of crystal.The weight ratio of mixed organic solvents and fluorenes coarse crystal is 0.3: 1~1.2: 1; Crystal drying after the washing, packing.
Below concrete steps of the present invention are further explained:
The lower molecular weight organic solvent of C1-C3 comprises the mixture of Virahol, methyl alcohol, ethanol, acetone or these organic solvents of technical grade described in the step (1); Non-polar solvent comprises the mixture of toluene, dimethylbenzene, benzene or these organic solvents of technical grade; The shared part by weight of non-polar solvent is 1%~30% in the mixed solvent.
Organic solvent comprises the mixture of toluene, dimethylbenzene, benzene or these organic solvents of technical grade described in the step (2).
Mixed organic solvents kind described in the step (3) is used identical with step (1), and the shared part by weight of non-polar solvent is 5~15% in the mixed solvent.
After employed organic solvent reclaims through rectifying in step (1), (2) and (3), can be recycled; The heavy constituent that solvent recuperation workshop section obtains are got back in the rectifying tower of washing oil processing.
The effect that the present invention reaches: the present invention utilizes crystallization process to make with extra care fluorenes, the raw materials used fluorenes enriched fraction that obtains for existing industrial rectifying workshop section, wherein fluorenes content is 50~80%, can obtain fluorenes content through primary crystallization after the technology of the present invention and be not less than 97% high purity product, fluorenes is brought up to more than 65% from 25% of existing technology the yield of raw material.
Can see by above-mentioned contrast, the present invention compared with prior art, main improvement has 2 points: the one, and increase pretreatment process, thereby removed most of polarity and non polar impurities in advance, this improves purification efficiency and the product yield greatly improved follow-up solvent crystallization workshop section.The 2nd, adopt the temperature lowering curve of optimizing, utilize automatic red-tape operati, reduce the temperature of crystallization terminal point, thereby on the basis that guarantees crystal purity, increased substantially product yield.
The invention has the advantages that, equipment and technology are simple, process does not have liquid and waste slag produced generation, the fluorenes product purity height that obtains, the yield height all adopts other organic solvent of technical grade in the process, operation and running cost are low, and whole device has adopted automatization control, has improved operational condition and has guaranteed the constant product quality degree simultaneously.
Description of drawings
Fig. 1 is device of the present invention and schematic flow sheet.
Among Fig. 1: the 1st, crystallizer, the 2nd, raw material washing impeller pump, the 3rd, product filtration washing impeller pump, the 4th, solution storage trough, the 5th, solvent recovery tower.
Embodiment
Below in conjunction with drawings and Examples the present invention is specified:
As shown in Figure 1, the fluorenes enriched fraction that gets off from header tank washs impeller pump 2 through raw material, adopts the mixture of organic solvent and non-polar organic solvent to carry out centrifuge washing, and the Solid Conveying and Melting that obtains enters crystallizer 1, carries out heating for dissolving and cooling crystallisation by cooling.After filtering and wash through whizzer 3, brilliant oar obtains the solid phase prod of fluorenes.The organic solvent that obtains in the above step reclaims and recycles through solvent recovery tower 5 after solution storage trough 4 is collected.
Embodiment 1
Raw material is the fluorenes cut 500g of fluorenes content 51.0%, preparation dimethylbenzene mass ratio is methyl alcohol-dimethylbenzene mixed solvent of 15%, according to mixed solvent: the mass ratio of fluorenes cut=1.2: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 346g, with thick fluorenes according to dimethylbenzene: the solvent quality ratio proportioning of thick fluorenes=0.4: 1 is warming up to 70 ℃ solid is all dissolved.Rate of temperature fall according to 40 ℃/h drops to 10 ℃ with system temperature then, filters, and with the above-mentioned mixed solvent washing crystal of 200g, uses gas chromatographic analysis behind the product drying, obtains purity and be 97.16% fluorenes product 171.3g, and the total recovery of fluorenes is 65.3%.
Embodiment 2
Raw material is the fluorenes cut 500g of fluorenes content 51.0%, preparation toluene mass ratio is ethanol-toluene mixed solvent of 30%, according to mixed solvent: the mass ratio of fluorenes cut=0.6: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 379g, with thick fluorenes according to toluene: the solvent quality ratio proportioning of thick fluorenes=0.7: 1 is warming up to 80 ℃ solid is all dissolved.Rate of temperature fall according to 35 ℃/h drops to 10 ℃ with system temperature then, filtering, is ethanol-toluene mixed solvent washing crystal of 15% with 52g toluene mass ratio, uses gas chromatographic analysis behind the product drying, obtain purity and be 97.23% fluorenes product 173.3g, the total recovery of fluorenes is 66.1%.
Embodiment 3
Raw material is the fluorenes cut 500g of fluorenes content 64.4%, preparation benzene mass ratio is Virahol-benzene mixed solvent of 20%, according to mixed solvent: the mass ratio of fluorenes cut=0.3: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 411g, with thick fluorenes according to benzene: the solvent quality ratio proportioning of thick fluorenes=1.1: 1 is warming up to 90 ℃ solid is all dissolved.Rate of temperature fall according to 30 ℃/h drops to 25 ℃ with system temperature then, filtering, is Virahol-benzene mixed solvent washing crystal of 5% with 98g benzene mass ratio, uses gas chromatographic analysis behind the product drying, obtain purity and be 97.11% fluorenes product 245.4g, the total recovery of fluorenes is 67.4%.
Embodiment 4
Raw material is the fluorenes cut 500g of fluorenes content 64.4%, preparation dimethylbenzene mass ratio is ethanol-dimethylbenzene mixed solvent of 1%, according to mixed solvent: the mass ratio of fluorenes cut=0.5: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 414g, with thick fluorenes according to dimethylbenzene: the solvent quality ratio proportioning of thick fluorenes=1.2: 1 is warming up to 90 ℃ solid is all dissolved.Rate of temperature fall according to 15 ℃/h drops to 15 ℃ with system temperature then, filter, it with 100g dimethylbenzene mass ratio ethanol-dimethylbenzene mixed solvent washing crystal of 5%, use gas chromatographic analysis behind the product drying, obtain purity and be 94.63% fluorenes product 210.0g, the total recovery of fluorenes is 61.7%.
Embodiment 5
Raw material is the fluorenes cut 500g of fluorenes content 74.5%, preparation dimethylbenzene mass ratio is acetone-ethanol-dimethylbenzene mixed solvent of 20%, according to mixed solvent: the mass ratio of fluorenes cut=0.5: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 415g, with thick fluorenes according to dimethylbenzene: the solvent quality ratio proportioning of thick fluorenes=0.6: 1 is warming up to 90 ℃ solid is all dissolved.Rate of temperature fall according to 25 ℃/h drops to 15 ℃ with system temperature then, filter, it with the 300g mass ratio acetone-ethanol-dimethylbenzene mixed solvent washing crystal of 3: 3: 1, use gas chromatographic analysis behind the product drying, obtain purity and be 98.41% fluorenes product 279.0g, the total recovery of fluorenes is 73.7%.
Embodiment 6
Raw material is the fluorenes cut 500g of fluorenes content 80.3%, preparation toluene mass ratio is methyl alcohol-toluene mixed solvent of 30%, according to mixed solvent: the mass ratio of fluorenes cut=0.9: 1 carries out centrifuge washing to the fluorenes cut, obtain thick fluorenes 424g, with thick fluorenes according to dimethylbenzene: the solvent quality ratio proportioning of thick fluorenes=0.6: 1 is warming up to 90 ℃ solid is all dissolved.Rate of temperature fall according to 35 ℃/h drops to 0 ℃ with system temperature then, filtering, is methyl alcohol-toluene mixed solvent washing crystal of 15% with 136g toluene mass ratio, uses gas chromatographic analysis behind the product drying, obtain purity and be 99.17% fluorenes product 340.1g, the total recovery of fluorenes is 84.1%.Methyl alcohol that uses in the process and toluene are through the rectifying recycling use, and fluorenes content is 39.9% in the heavy constituent that solvent recuperation workshop section obtains, and get back in the rectifying tower of washing oil processing.
The method of the open and purifying refined fluorene by crystallizing that proposes of the present invention, those skilled in the art can be by using for reference this paper content, and links such as appropriate change raw material, processing parameter realize.Method of the present invention and product are described by preferred embodiment, person skilled obviously can be in not breaking away from content of the present invention, spirit and scope to method as herein described with product is changed or suitably change and combination, realize the technology of the present invention.Special needs to be pointed out is, the replacement that all are similar and change apparent to those skilled in the artly, they are regarded as being included in spirit of the present invention, scope and the content.