CN110746347A - A kind of tetrachloropyridine rectification residue recovery and reuse method - Google Patents
A kind of tetrachloropyridine rectification residue recovery and reuse method Download PDFInfo
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- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
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- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
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Abstract
本发明提供了一种四氯吡啶精馏残液回收和再利用方法，该方法将四氯吡啶精馏残液通过醇类溶剂浸泡去除焦油、水蒸气蒸馏提取五氯吡啶和惰性溶剂脱水提纯的方法。本方法提纯出来五氯吡啶可与硫化碱加入到反应釜中，保温反应后热过滤再酸化可得2,3,5,6‑四氯‑4‑吡啶硫醇纯品。本方法操作简单、可从废料四氯吡啶精馏残液中获得高纯度的五氯吡啶，该五氯吡啶还可用于2,3,5,6‑四氯‑4‑吡啶硫醇的合成，较容易实现工业化。The invention provides a method for recovering and reusing the tetrachloropyridine rectification residue. In the method, the tetrachloropyridine rectification residue is soaked in an alcohol solvent to remove tar, and the pentachloropyridine is extracted by steam distillation and dehydrated and purified by an inert solvent. method. The pentachloropyridine purified by the method can be added to the reaction kettle with alkali sulfide, and the pure product of 2,3,5,6-tetrachloro-4-pyridinethiol can be obtained by thermal filtration and acidification after thermal insulation reaction. The method is simple to operate, can obtain high-purity pentachloropyridine from waste tetrachloropyridine rectification residue, and the pentachloropyridine can also be used for the synthesis of 2,3,5,6-tetrachloro-4-pyridinethiol, It is easier to realize industrialization.
Description
技术领域technical field
本发明属于资源与环境技术领域，涉及废液处理领域，具体涉及四氯吡啶精馏残液的回收和再利用。The invention belongs to the technical field of resources and environment, relates to the field of waste liquid treatment, and in particular relates to the recovery and reuse of tetrachloropyridine rectification residual liquid.
背景技术Background technique
四氯吡啶精馏残液是现有四氯吡啶生产工艺中使用吡啶与氯气进行高温催化氯化，反应气体冷凝并在收集釜中收集，然后将收集釜中物料转入精馏釜进行精馏提纯后釜中残留的物料。上述精馏釜精馏残液在现有生产工艺中四氯吡啶精馏残液约占成品四氯吡啶的5 ~ 10%，占比相对较大。以往均将四氯吡啶精馏残液以危废的形式处理，极大的增加了生产成本和环保压力。目前并未报道较好的处理方法。The tetrachloropyridine rectification raffinate is the use of pyridine and chlorine for high-temperature catalytic chlorination in the existing tetrachloropyridine production process, the reaction gas is condensed and collected in the collection kettle, and then the material in the collection kettle is transferred to the rectification kettle for rectification The material remaining in the kettle after purification. The tetrachloropyridine rectification raffinate of the above-mentioned rectifying still rectification raffinate accounts for about 5 to 10% of the finished tetrachloropyridine in the existing production process, and the proportion is relatively large. In the past, the tetrachloropyridine distillation residue was treated in the form of hazardous waste, which greatly increased the production cost and environmental protection pressure. A better treatment method has not been reported so far.
2,3,5,6-四氯-4-吡啶硫醇是一种重要的吡啶类农药中间体，主要应用于制备2,3,5,6-四氯-4-甲磺酰基吡啶，于防止霉菌对农作物的侵害，另外还在油墨、造纸、纺织和聚合材料等领域中有较为广泛的应用。若能将四氯吡啶精馏残液回收再处理进而用于制备2,3,5,6-四氯-4-吡啶硫醇，是一种废物的资源化利用。2,3,5,6-Tetrachloro-4-pyridinethiol is an important pyridine pesticide intermediate, which is mainly used in the preparation of 2,3,5,6-tetrachloro-4-methanesulfonylpyridine. To prevent the damage of mold to crops, it is also widely used in the fields of ink, paper, textile and polymer materials. If the tetrachloropyridine rectification residue can be recovered and reprocessed and then used to prepare 2,3,5,6-tetrachloro-4-pyridinethiol, it is a kind of resource utilization of waste.
发明内容SUMMARY OF THE INVENTION
本发明目的是提供一种四氯吡啶精馏残液回收和再利用方法。该方法原料来源于精馏残液，通过对其再利用可直接获得高纯度产物五氯吡啶，进一步的还可以制备得到高纯度的2,3,5,6-四氯-4-吡啶硫醇。The object of the present invention is to provide a method for recovering and reusing tetrachloropyridine rectification residue. The raw material of the method comes from the rectification residue, and the high-purity product pentachloropyridine can be directly obtained by reusing it, and further high-purity 2,3,5,6-tetrachloro-4-pyridinethiol can be prepared .
本发明是通过如下技术方案实现的：The present invention is achieved through the following technical solutions:
一种四氯吡啶精馏残液回收和再利用方法，包括以下步骤：A method for recovering and reusing tetrachloropyridine rectification residue, comprising the following steps:
a）将四氯吡啶精馏残液与醇类溶剂在50 ~ 60 ℃搅拌均匀后降温至30℃以下并过滤；所述四氯吡啶精馏残液与醇类溶剂的质量比为1：（0.5 ~ 2.0）；所述四氯吡啶精馏残液为吡啶氯化产物四氯吡啶和五氯吡啶精馏分离产生的残液，其中五氯吡啶含量为40 ~ 50%，四氯吡啶含量为2 ~ 5%，吡啶焦油含量为30 ~ 40%，碳化物含量为5 ~ 20%；a) Stir the tetrachloropyridine rectification residue and the alcohol solvent at 50-60°C, then cool down to below 30°C and filter; the mass ratio of the tetrachloropyridine rectification residue to the alcohol solvent is 1: ( 0.5～2.0); Described tetrachloropyridine rectification raffinate is the raffinate that pyridine chloride product tetrachloropyridine and pentachloropyridine rectification separation produces, and wherein pentachloropyridine content is 40～50%, and tetrachloropyridine content is 2 to 5%, the pyridine tar content is 30 to 40%, and the carbide content is 5 to 20%;
b）将a）步骤过滤所得滤饼破碎后加入水中，并通入水蒸气进行蒸馏，用水蒸汽带出滤饼中的有效成分五氯吡啶，得五氯吡啶水混合物；b) crushing the filter cake obtained in step a), adding it to water, and introducing water vapor for distillation, and taking out the active ingredient pentachloropyridine in the filter cake with water vapor to obtain a pentachloropyridine water mixture;
c）将b）步骤所述五氯吡啶水混合物过滤后，滤饼与惰性溶剂混合后，蒸馏脱出惰性溶剂、水及残留微量杂质，残液冷却即为五氯吡啶产品。c) After filtering the pentachloropyridine-water mixture described in step b), after mixing the filter cake with the inert solvent, the inert solvent, water and residual trace impurities are distilled off, and the residual liquid is cooled to obtain the pentachloropyridine product.
优选的该五氯吡啶产品与硫化碱在水相中反应、过滤及酸化后可得2,3,5,6-四氯-4-吡啶硫醇。2,3,5,6-tetrachloro-4-pyridinethiol can be obtained after the preferred pentachloropyridine product is reacted with sulfide base in aqueous phase, filtered and acidified.
以四氯吡啶精馏残液制备2,3,5,6-四氯-4-吡啶硫醇的方法具体步骤中：In the specific steps of the method for preparing 2,3,5,6-tetrachloro-4-pyridinethiol with tetrachloropyridine rectification residue:
优选的步骤b）中所述醇类溶剂包括甲醇、乙醇、异丙醇和叔丁醇；In the preferred step b), the alcoholic solvent includes methanol, ethanol, isopropanol and tert-butanol;
优选的步骤b）中所述的精馏残液与醇类溶剂的质量比为1：（1 ~ 1.5）；The mass ratio of the rectification residue described in the preferred step b) to the alcohol solvent is 1: (1 ~ 1.5);
优选的，步骤c）所述滤饼与水的质量比为1：（1 ~ 3）；Preferably, the mass ratio of the filter cake to water in step c) is 1: (1 ~ 3);
优选的，步骤d）中所述惰性溶剂包括四氯化碳、甲苯、氯苯、二甲苯；Preferably, the inert solvent in step d) includes carbon tetrachloride, toluene, chlorobenzene, and xylene;
优选的，步骤d）中五氯吡啶和惰性溶剂的质量比为1：（0.3 ~ 0.6）。Preferably, the mass ratio of pentachloropyridine and inert solvent in step d) is 1:(0.3-0.6).
优选的，步骤d）中所述五氯吡啶产品的纯度＞ 97%。Preferably, the purity of the pentachloropyridine product described in step d) is greater than 97%.
优选的，所述五氯吡啶与硫化钠在水与四氢呋喃的混合物中回流4 ~ 8小时，然后在50 ~ 60 ℃下过滤，滤液加盐酸进行酸化，然后抽滤可得2,3,5,6-四氯-4-吡啶硫醇。Preferably, the pentachloropyridine and sodium sulfide are refluxed in a mixture of water and tetrahydrofuran for 4 to 8 hours, then filtered at 50 to 60 ° C, and the filtrate is acidified by adding hydrochloric acid, and then suction filtration to obtain 2, 3, 5, 6-Tetrachloro-4-pyridinethiol.
该方法将四氯吡啶精馏残液通过醇类溶剂浸泡去除焦油、水蒸气蒸馏提取五氯吡啶和惰性溶剂脱水提纯的方法。本方法提纯出来五氯吡啶可与硫化碱按照一定的比例加入到反应釜中，保温反应后热过滤再酸化可得2,3,5,6-四氯-4-吡啶硫醇纯品。本方法操作简单、可从废料四氯吡啶精馏残液中获得高纯度的五氯吡啶，该五氯吡啶还可用于2,3,5,6-四氯-4-吡啶硫醇的合成，较容易实现工业化。In the method, the tetrachloropyridine rectification residue is soaked in an alcohol solvent to remove tar, the pentachloropyridine is extracted by steam distillation, and the inert solvent is dehydrated and purified. The pentachloropyridine purified by the method can be added to the reaction kettle according to a certain proportion with alkali sulfide, and after the heat preservation reaction, the 2,3,5,6-tetrachloro-4-pyridinethiol pure product can be obtained by hot filtration and acidification. The method is simple to operate, can obtain high-purity pentachloropyridine from waste tetrachloropyridine rectification residue, and the pentachloropyridine can also be used for the synthesis of 2,3,5,6-tetrachloro-4-pyridinethiol, It is easier to realize industrialization.
与现有技术相比，本发明的优点在于：Compared with the prior art, the advantages of the present invention are:
1、本发明方法原料来自四氯吡啶精馏工段的精馏残液，实现了废物的再利用，减少环保支出及环保压力。1. The raw material of the method of the present invention comes from the rectification raffinate of the tetrachloropyridine rectification section, which realizes the reuse of waste and reduces environmental protection expenditure and environmental protection pressure.
2、本发明的方法所得到的产品五氯吡啶产品的纯度＞97%，2,3,5,6-四氯-4-吡啶硫醇成品纯度达到98%以上，并且可带来可观的经济效益。2. The purity of the pentachloropyridine product obtained by the method of the present invention is more than 97%, and the purity of the 2,3,5,6-tetrachloro-4-pyridinethiol product reaches more than 98%, and can bring considerable economical benefits benefit.
3、本发明的部分溶剂为水，水作为分离纯化的介质具有价廉、安全、无污染、产物易于分离的优点。3. Part of the solvent of the present invention is water, and water as a medium for separation and purification has the advantages of low cost, safety, no pollution, and easy separation of products.
具体实施方式Detailed ways
下面结合实施例对本发明做进一步的说明。The present invention will be further described below in conjunction with the embodiments.
实施例1Example 1
将100 g精馏残液与100 g乙醇在50 ~ 60 ℃下搅拌均匀后降温至30 ℃以下并进行过滤。上述滤饼100 g加入200 g水中并通水蒸汽进行水蒸气蒸馏，将收集到的馏份过滤，取破碎后的滤饼100 g加入50 g二甲苯，然后分水除杂，分水完毕后蒸出体系中的二甲苯，即得白色的五氯吡啶纯品41 g，HPLC含量98.34%。取得到的五氯吡啶40 g与12 g硫化钠在水与四氢呋喃（体积比为1:1）的混合物中回流5小时，然后在55 ℃下过滤，滤液加盐酸进行酸化，然后抽滤可得2,3,5,6-四氯4-吡啶硫醇31.5 g，含量98.03%，收率82.23%。Stir 100 g of distillation residue and 100 g of ethanol at 50-60 °C, then cool down to below 30 °C and filter. Add 100 g of above-mentioned filter cake into 200 g of water and carry out steam distillation through steam, filter the collected fraction, take 100 g of the crushed filter cake and add 50 g of xylene, then separate water to remove impurities, and after water separation is completed The xylene in the system was evaporated to obtain 41 g of pure white pentachloropyridine with an HPLC content of 98.34%. The obtained pentachloropyridine 40 g and 12 g sodium sulfide were refluxed in a mixture of water and tetrahydrofuran (volume ratio of 1:1) for 5 hours, then filtered at 55 °C, and the filtrate was acidified by adding hydrochloric acid, and then suction filtration to obtain 2,3,5,6-tetrachloro-4-pyridinethiol 31.5 g, content 98.03%, yield 82.23%.
实施例2Example 2
步骤同实施例1，区别在于乙醇投入量为150 g，产品五氯吡啶46 g，HPLC含量98.27%。后续产2,3,5,6-四氯4-吡啶硫醇31.6 g，含量98.77%，收率82.49%。The steps are the same as in Example 1, except that the ethanol input amount is 150 g, the product pentachloropyridine is 46 g, and the HPLC content is 98.27%. The subsequent production of 2,3,5,6-tetrachloro-4-pyridinethiol was 31.6 g, with a content of 98.77% and a yield of 82.49%.
实施例3Example 3
步骤同实施例1，区别在于惰性溶剂选用甲苯，产品43 g，HPLC含量97.43%。步骤同实施例1，区别在于五氯吡啶投入量增加为43 g，产2,3,5,6-四氯4-吡啶硫醇33.2 g，含量99.01%，收率86.67%。The steps are the same as in Example 1, except that the inert solvent is selected from toluene, the product is 43 g, and the HPLC content is 97.43%. The steps were the same as those in Example 1, except that the input amount of pentachloropyridine was increased to 43 g, and 33.2 g of 2,3,5,6-tetrachloro-4-pyridinethiol was produced, with a content of 99.01% and a yield of 86.67%.
实施例4Example 4
步骤同实施例1，区别在于醇类溶剂选用异丙醇且投入量为100 g，产品45 g，HPLC含量98.37%。后续产2,3,5,6-四氯4-吡啶硫醇32.4 g，含量98.65%，收率82.58%。The steps are the same as in Example 1, except that the alcoholic solvent is selected from isopropanol and the input amount is 100 g, the product is 45 g, and the HPLC content is 98.37%. The subsequent production of 2,3,5,6-tetrachloro-4-pyridinethiol was 32.4 g, with a content of 98.65% and a yield of 82.58%.
实施例5Example 5
步骤同实施例1，区别在于二甲苯的投入量为80 g，产品五氯吡啶45 g，HPLC含量99.26%。后续产2,3,5,6-四氯4-吡啶硫醇34.7 g，含量99.27%，收率90.58%。The steps are the same as in Example 1, except that the input amount of xylene is 80 g, the product pentachloropyridine is 45 g, and the HPLC content is 99.26%. The subsequent production of 2,3,5,6-tetrachloro-4-pyridinethiol was 34.7 g, with a content of 99.27% and a yield of 90.58%.
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| CN105085381A (en) * | 2014-05-12 | 2015-11-25 | 利尔化学股份有限公司 | Method for separating chloropyridine mixture |
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Patent Citations (5)
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|---|---|---|---|---|
| US4225718A (en) * | 1979-02-22 | 1980-09-30 | The Dow Chemical Company | Process for recovering 2,3,5,6-tetrachloropyridine |
| US4515953A (en) * | 1983-04-22 | 1985-05-07 | Kalama Chemical, Inc. | Production of polychlorinated pyridine mixtures by liquid phase chlorination of pyridine or pyridine hydrochloride |
| CN101768107A (en) * | 2010-01-13 | 2010-07-07 | 北京颖泰嘉和科技股份有限公司 | Method for preparing polychlorinated pyridine |
| CN102351785A (en) * | 2011-08-11 | 2012-02-15 | 江苏九九久科技股份有限公司 | Method for preparing 3, 5, 6-trichloropyridin-2-ol sodium |
| CN105085381A (en) * | 2014-05-12 | 2015-11-25 | 利尔化学股份有限公司 | Method for separating chloropyridine mixture |
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Denomination of invention: A method for recovering and reusing residual liquid from tetrachloropyridine distillation Granted publication date: 20230214 Pledgee: China Construction Bank Corporation Yueyang Branch Pledgor: HUNAN BIDE BIOCHEMICAL TECHNOLOGY CO.,LTD. Registration number: Y2024980045899 |
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