阅读说明：本技术 由含有烷基蒽的产物中分离2-烷基蒽并采用催化氧化工艺制备2-烷基蒽醌的方法 (Method for separating 2-alkyl anthracene from products containing alkyl anthracene and preparing 2-alkyl anthraquinone by adopting catalytic oxidation process ) 是由 郑博 潘智勇 朱振兴 费建奇 毛俊义 宗保宁 于 2019-04-15 设计创作，主要内容包括：本发明涉及2-烷基蒽醌的制备领域,具体公开了一种由含有烷基蒽的产物中分离2-烷基蒽并采用催化氧化工艺制备2-烷基蒽醌的方法：(1)由蒽制备含有烷基蒽的反应产物；(2)将含有烷基蒽的反应产物进行熔融结晶分离蒽和蒸馏分离2-烷基蒽；(3)在氧化条件下以及在氧化反应溶剂和催化剂的存在下,将2-烷基蒽与氧化剂接触进行氧化反应,所述氧化剂为过氧化氢,所述催化剂含有载体和负载在载体上的金属活性组分,所述金属活性组分选自碱土金属、过渡金属和镧系金属中的一种或多种。本发明可显著降低含有烷基蒽的反应产物的分离操作难度,氧化体系绿色高效,转化率高达90.12％,选择性高达99.02％。(The invention relates to the field of preparation of 2-alkylanthraquinone, and particularly discloses a method for separating 2-alkylanthraquinone from an alkylanthraquinone-containing product and preparing the 2-alkylanthraquinone by adopting a catalytic oxidation process, which comprises the following steps: (1) preparing a reaction product containing an alkyl anthracene from an anthracene; (2) melting and crystallizing the reaction product containing alkyl anthracene to separate anthracene and distilling to separate 2-alkyl anthracene; (3) the 2-alkyl anthracene is contacted with an oxidizing agent which is hydrogen peroxide under oxidizing conditions and in the presence of an oxidizing reaction solvent and a catalyst to carry out an oxidation reaction, and the catalyst contains a carrier and a metal active component which is supported on the carrier and is selected from one or more of alkaline earth metals, transition metals and lanthanide metals. The method can obviously reduce the difficulty of separation operation of reaction products containing alkyl anthracene, and the oxidation system is green and efficient, the conversion rate is up to 90.12%, and the selectivity is up to 99.02%.)

1. A process for separating a 2-alkyl anthracene from an alkyl anthracene-containing product and producing the 2-alkyl anthraquinone using a catalytic oxidation process, the process comprising the steps of:

(1) preparing a reaction product containing an alkyl anthracene from an anthracene;

(2) separating the reaction product containing alkyl anthracene obtained from step (1), the separation method comprising: melting crystallization separation of anthracene and distillation separation of 2-alkyl anthracene;

(3) contacting the 2-alkyl anthracene obtained in the step (2) with an oxidizing agent, namely hydrogen peroxide, under oxidizing conditions and in the presence of an oxidizing reaction solvent and a catalyst, wherein the catalyst contains a carrier and a metal active component loaded on the carrier, and the metal active component is selected from one or more of alkaline earth metals, transition metals and lanthanide metals.

2. The production method according to claim 1, wherein, in the step (1), the method for producing the reaction product containing the alkyl anthracene from the anthracene includes: under the alkylation condition and in the presence of an alkylation reaction solvent and a catalyst, contacting anthracene with an alkylation reagent to carry out alkylation reaction;

preferably, the contact mode is as follows: the raw material liquid containing anthracene, catalyst and alkylation reaction solvent is contacted with alkylation reagent to make alkylation reaction.

3. The preparation method according to claim 2, wherein the alkylating reagent is one or more of olefins, alcohols, halogenated hydrocarbons and ethers having 2 to 8 carbon atoms, preferably one or more of olefins, alcohols, halogenated hydrocarbons and ethers having 4 to 6 carbon atoms, and more preferably mono-olefins having 4 to 6 carbon atoms.

4. The production process according to claim 2 or 3, wherein in the step (1), the molar ratio of anthracene to the alkylating agent is 0.2:1 to 20:1, preferably 0.5:1 to 5: 1.

5. The method according to claim 2, wherein in the step (1), the alkylation reaction solvent is a solvent having a dielectric constant of 1 to 10 at 20 ℃, and the alkylation reaction solvent is C₆Above, preferably C₆-C₁₂One or more of paraffins, naphthenes and aromatics; wherein the aromatic hydrocarbon is substituted or unsubstituted, preferably one or more of mono-or multi-substituted benzene; more preferably one or more of benzene multi-substituted compounds, the substituent is C₁-C₄One or more of alkyl and halogen elements of (a); further preferably, the alkylation reaction solvent is one or more of polyalkyl substitutes of benzene; most preferably, the first and second substrates are,the alkylation reaction solvent is selected from one or more of 1,3, 5-trimethylbenzene, 1,2,3, 5-tetramethylbenzene, 1,3,4, 5-tetramethylbenzene, 1,3,5, 6-tetramethylbenzene and 2,3,5, 6-tetramethylbenzene;

the content of anthracene is 5 to 60 wt%, preferably 8 to 50 wt%, based on the total weight of anthracene and the alkylation reaction solvent.

6. The production method according to any one of claims 2 to 5, wherein in the step (1), the alkylation reaction conditions include: the reaction temperature is 100-250 ℃, preferably 120-200 ℃; the reaction pressure is 0-1MPa, preferably 0.05-0.5 MPa; the reaction time is 0.01-48h, preferably 0.5-24 h.

7. The production method according to any one of claims 2 to 5, wherein in the step (1), the catalyst is selected from one or more of liquid acids, preferably methanesulfonic acid and/or p-toluenesulfonic acid; the content of the catalyst is 0.01 to 50% by weight, preferably 0.5 to 30% by weight, based on the total weight of the raw material liquid containing anthracene, the catalyst and the alkylation reaction solvent.

8. The production method according to any one of claims 1 to 7, wherein the reaction product containing alkyl anthracene obtained through step (1) contains anthracene and a series of alkyl anthracene products containing 2-alkyl anthracene;

the step (2) comprises the following steps:

(2-2) heating the reaction product containing the alkyl anthracene obtained in the step (1) to a molten state, cooling and crystallizing, separating to obtain an anthracene crystal and a feed liquid containing a series of alkyl anthracene products of 2-alkyl anthracene, heating the anthracene crystal for sweating, and separating the sweating liquid and the anthracene crystal;

(2-3) separating 2-alkyl anthracene from the series of alkyl anthracene products containing 2-alkyl anthracene by one or more distillation steps.

9. The preparation method according to claim 8, wherein, in the step (2-2), the melting temperature is 200-.

10. The preparation method according to claim 8 or 9, wherein in the step (2-2), the cooling crystallization temperature is 180-210 ℃, the cooling rate of the cooling crystallization is 0.1-10 ℃/h, and the cooling crystallization time is 1-5 h; preferably, the cooling crystallization temperature is 190-.

11. The production method according to claim 10, wherein in the step (2-2), in the cooling crystallization, a step of adding seed anthracene in an amount of 0.1 to 10% by weight, preferably 0.2 to 5% by weight, based on the mass of the molten mixture is further included.

12. The production method according to claim 8 or 9, wherein in the step (2-2), the temperature increase rate at which the anthracene crystal is subjected to sweating is 0.1 to 8 ℃/h, preferably 0.2 to 4 ℃/h; raising the temperature to a temperature lower than the melting temperature of the anthracene crystal to stop sweating, preferably raising the temperature to a temperature lower than or equal to 210 ℃ to stop sweating, more preferably raising the temperature to a temperature 5 to 15 ℃ higher than the cooling crystallization temperature and stopping sweating below 210 ℃; further preferably, the sweating completion temperature is 190-210 ℃, and most preferably 195-205 ℃.

13. The production method according to claim 12, wherein the amount of perspiration is 5 to 40% by weight, preferably 10 to 30% by weight, based on the mass of the anthracene crystal.

14. The method of claim 12, further comprising circulating sweat back to the melt crystallization step for melt crystallization with the reaction product containing alkyl anthracene.

15. The production method according to claim 8, wherein, in the step (2-3), when the series of alkyl anthracene products containing 2-alkyl anthracene is a mixture of two substances, or a mixture of three or more substances, and the boiling point of 2-alkyl anthracene is the lowest or the highest; then a one-step distillation is performed to separate the 2-alkyl anthracene.

16. The production method according to claim 8, wherein, in the step (2-3), when the series of alkyl anthracene products containing 2-alkyl anthracene is a mixture of three or more substances, and the boiling point of 2-alkyl anthracene is between the substance with the highest boiling point and the substance with the lowest boiling point in the mixture; then a multi-stage distillation is performed, the multi-stage distillation method comprising:

mode 1:

carrying out first distillation on feed liquid of a series of alkyl anthracene products containing 2-alkyl anthracene, and separating to obtain distillate containing a light component Cj 1-anthracene and a bottom product containing a heavy component Cj 2-anthracene; subjecting the distillate containing the light component Cj 1-anthracene to second distillation to obtain a distillate containing the light component Cj 3-anthracene and a bottom product containing the target product Ci-anthracene;

wherein, the light component Cj 1-anthracene is an alkyl anthracene product with the total carbon number j1 of an alkyl side chain being an integer which is more than 1 and less than j1 and less than i +1, the heavy component Cj 2-anthracene is an alkyl anthracene product with the total carbon number j2 of the alkyl side chain being an integer which is more than i and less than j2 and less than 41, and the light component Cj 3-anthracene is an alkyl anthracene product with the total carbon number j3 of the alkyl side chain being an integer which is more than 1 and less than j3 and less than i;

alternatively, the first and second electrodes may be,

mode 2:

carrying out third distillation on feed liquid of a series of alkyl anthracene products containing 2-alkyl anthracene to obtain distillate containing a light component Cm 1-anthracene and a bottom product containing a heavy component Cm 2-anthracene; carrying out fourth distillation on the bottom product containing the heavy component Cm 2-anthracene to obtain a distillate containing the target product Ci-anthracene and a bottom product containing the heavy component Cm 3-anthracene;

wherein the light component Cm 1-anthracene is an alkyl anthracene product with the total carbon number of the alkyl side chain m1 being an integer of 1< m 1< i, the heavy component Cm 2-anthracene is an alkyl anthracene product with the total carbon number of the alkyl side chain m2 being an integer of i-1 < m 2< 41, and Cm 3-anthracene is an alkyl anthracene product with the total carbon number of the alkyl side chain m3 being an integer of i < m3 < 41;

wherein, in the target product Ci-anthracene, i represents the total carbon number of an alkyl side chain, and i is an integer of 4-7.

17. The production method according to claim 16, wherein in the multi-step reduced pressure distillation step, mode 1, the conditions of the first reduced pressure distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-; more preferably, the pressure at the top of the tower is 0.1-10KPa, the temperature at the bottom of the tower is 210-340 ℃, the number of theoretical plates is 30-75, and the reflux ratio at the top of the tower is 1-7; further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 260 ℃ to 320 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 3.

18. The production method according to claim 16 or 17, wherein in the multi-step reduced pressure distillation step, mode 1, the conditions of the second reduced pressure distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-330 ℃, the number of theoretical plates is 20-90, and the reflux ratio at the top of the distillation tower is 0.5-8; more preferably, the pressure at the top of the tower is 0.1-10KPa, the temperature at the bottom of the tower is 200-310 ℃, the number of theoretical plates is 30-75, and the reflux ratio at the top of the tower is 1-7; further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 220-305 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 5.

19. The production method according to claim 16, wherein in the multi-step reduced pressure distillation step, mode 2, the conditions of the third reduced pressure distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-; more preferably, the pressure at the top of the tower is 0.1-10KPa, the temperature at the bottom of the tower is 210-340 ℃, the number of theoretical plates is 30-75, and the reflux ratio at the top of the tower is 1-7; further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 260 ℃ to 320 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 3.

20. The production method according to claim 16 or 19, wherein in the multi-step reduced pressure distillation step, mode 2, the fourth reduced pressure distillation conditions include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-330 ℃, the number of theoretical plates is 20-90, and the reflux ratio at the top of the distillation tower is 0.5-8; more preferably, the pressure at the top of the tower is 0.1-10KPa, the temperature at the bottom of the tower is 200-310 ℃, the number of theoretical plates is 30-75, and the reflux ratio at the top of the tower is 1-7; further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 220-305 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 5.

21. The production method according to any one of claims 8 to 20, wherein the reaction product containing an alkyl anthracene obtained through step (1) further contains a reaction solvent;

the step (2) further comprises: a step (2-1) of separating the reaction solvent prior to the separation of anthracene by melt crystallization and the separation of 2-alkyl anthracene by distillation;

(2-1) the separation method comprising: and (2) distilling the reaction product containing the alkyl anthracene obtained in the step (1) in a distillation tower to obtain a distillate containing the reaction solvent and a tower bottom product containing anthracene and a series of alkyl anthracene products containing 2-alkyl anthracene.

22. The production method according to claim 21, wherein in the step (2-1), the conditions of distillation include: the bottom temperature of the distillation column is 100-300 ℃, preferably 150-200 ℃, and the pressure at the top of the distillation column is normal pressure.

23. The process according to claim 1, wherein in step (3), the metal active component is selected from one or more of group IVB, group VB, group VIB, group VIIB, group VIII metals and lanthanide metals, preferably a combination of a lanthanide metal and at least one metal selected from group IVB, group VB, group VIB, group VIIB and group VIII metals.

24. The production method according to claim 23, wherein the metal active component is selected from one or more of Ti, Zr, V, Cr, Mo, Mn, Ru, and La, preferably a combination of La and at least one selected from V, Ti, Zr, Cr, Mn, Ru, and Mo.

25. The production method according to claim 1, wherein the support is a heat-resistant inorganic oxide selected from the group consisting of silica, magnesia and a silicon-aluminum composite oxideIn the silicon-aluminum composite oxide, SiO is calculated by oxide₂In an amount of 0.01 to 70 wt.%, preferably 5 to 40 wt.%, Al₂O₃The content of (B) is 30 to 99.9% by weight, preferably 60 to 95% by weight.

26. The production method according to any one of claims 1 and 23 to 25, wherein the active metal component is contained in an amount of 0.01 to 40% by weight, preferably 0.1 to 30% by weight, in terms of element content, based on the weight of the carrier in the catalyst.

27. The production method according to claim 26, wherein the active metal component in the catalyst is a combination of a lanthanoid metal and a transition metal, and the mass ratio of the transition metal to the lanthanoid metal is 1 to 20:1 in terms of the element content.

28. The production method according to any one of claims 1 and 23 to 27, wherein the production method of the catalyst comprises: impregnating a support with a solution containing a soluble compound of a metal selected from one or more of alkaline earth metals, transition metals and lanthanoid metals, drying and calcining the impregnated support.

29. The process according to claim 28, wherein the soluble compound of a metal is a soluble compound of one or more metals selected from the group consisting of group ivb, group vb, group vib, group viib, group viii metals and the lanthanides, preferably a combination of a soluble compound of a lanthanide metal and a soluble compound of a metal selected from at least one of the group ivb, group vb, group vib, group viib and group viii metals.

30. The production method according to claim 29, wherein the soluble compound of the metal is a soluble compound of one or more metals selected from Ti, Zr, V, Cr, Mo, Mn, Ru and La, preferably a combination of a soluble compound of La and a soluble compound of a metal selected from at least one of V, Ti, Zr, Cr, Mn, Ru and Mo.

31. The process according to claim 28, wherein the support and the soluble compound of the metal are used in such an amount that the active metal component is contained in an amount of 0.01 to 40% by weight, preferably 0.1 to 30% by weight, calculated as element, based on the weight of the support in the catalyst.

32. The production method according to claim 31, wherein the soluble compound of a metal is a combination of a soluble compound of a lanthanide metal and a soluble compound of a transition metal, and the soluble compound of a metal is used in an amount such that the mass ratio of the transition metal to the lanthanide metal in terms of element in the catalyst is 1-20: 1.

33. The method of claim 28, wherein the impregnating conditions include: the dipping temperature is 0-100 ℃, preferably 20-80 ℃, and the dipping time is 4-24h, preferably 6-12 h; drying the impregnated carrier at 90-125 deg.C for 1-12 h; the temperature for roasting the impregnated carrier is 300-700 ℃, and the roasting time is 2-6 h.

34. The method of claim 1, wherein the contacting is by: a raw material liquid containing a 2-alkylanthracene, a catalyst and an oxidation reaction solvent is brought into contact with an oxidizing agent to carry out an oxidation reaction.

35. The production process according to claim 34, wherein the catalyst is contained in an amount of 0.01 to 50% by weight, preferably 0.5 to 30% by weight, based on the total weight of the catalyst and the oxidation reaction solvent.

36. The production method according to any one of claims 1 and 23 to 35, wherein the oxidation reaction solvent is a solvent having a dielectric constant of more than 2.8 at 20 ℃, preferably, the oxidation reaction solvent has a dielectric constant of more than 2.8 to 50 or less at 20 ℃A solvent; more preferably, the oxidation reaction solvent is one or more of aliphatic alcohol with carbon number of 1-4, tetrahydrofuran, acetone, N-alkyl substituted amide and N-alkyl pyrrolidone; wherein the number of alkyl substituents is 1-2, each alkyl substituent is independently C₁-C₄Alkyl groups of (a); most preferably, the oxidation reaction solvent is selected from one or more of methanol, t-butanol, acetone, N-dimethylformamide, N-dimethylacetamide, N-dimethylpropionamide, N-methylpyrrolidone, and N-ethylpyrrolidone;

the total content of the 2-alkylanthracene is 0.1 to 80% by weight, preferably 5 to 50% by weight, based on the total weight of the 2-alkylanthracene and the oxidation reaction solvent.

37. The production method according to any one of claims 1 and 23 to 35, wherein the oxidation reaction solvent is a combination of a solvent a having a dielectric constant of 1 to 10 at 20 ℃ and a solvent B having a dielectric constant of more than 10 to 50 or less at 20 ℃;

the solvent A is C₆Above, preferably C₆-C₁₂One or more of paraffins, naphthenes and aromatics; wherein the aromatic hydrocarbon is substituted or unsubstituted, preferably one or more of monobasic or polybasic substituted substances of benzene, more preferably one or more of polybasic substituted substances of benzene, and the substituent is C₁-C₄One or more of alkyl and halogen elements of (a); further preferably, the solvent A is one or more of polyalkyl substituents of benzene, and most preferably, the solvent A is one or more selected from 1,3, 5-trimethylbenzene, 1,2,3, 5-tetramethylbenzene, 1,3,4, 5-tetramethylbenzene, 1,3,5, 6-tetramethylbenzene and 2,3,5, 6-tetramethylbenzene;

the solvent B is N-alkyl substituted amide, wherein the number of alkyl substituents is 1-2, and each alkyl substituent is independently C₁-C₄Alkyl groups of (a); more preferably, the solvent B is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide and N, N-dimethylpropionamide, and most preferably, the solvent B is N, N-dimethylformamide;

the total content of the 2-alkylanthracene is 0.1 to 80% by weight, preferably 5 to 50% by weight, based on the total weight of the 2-alkylanthracene and the oxidation reaction solvent.

38. The method according to claim 37, wherein the volume ratio of solvent a to solvent B is 0.01 to 100, preferably 0.05 to 10.

39. The production method according to any one of claims 1 and 23 to 35, wherein the conditions of the oxidation reaction include: the reaction temperature is 10-200 ℃, and preferably 20-120 ℃; the reaction pressure is 0-1MPa, preferably 0-0.5 MPa; the reaction time is 0.01-48h, preferably 0.5-24 h.

40. The production method according to any one of claims 1, 23 to 35, wherein the hydrogen peroxide is used in the form of an aqueous hydrogen peroxide solution; the molar ratio of oxidant to 2-alkyl anthracene is 0.01:1 to 100:1, preferably 1:1 to 50: 1.

Technical Field

The invention relates to a preparation method of an organic matter, in particular to a method for separating 2-alkyl anthracene from a product containing alkyl anthracene and preparing the 2-alkyl anthraquinone by adopting a catalytic oxidation process.

Background

Hydrogen peroxide is an important green basic chemical, has high industrial relevance, and has become the first major country for hydrogen peroxide production since 2008, and the consumption amount is over 1000 million t/a (calculated by 27.5%) in 2015. At present, the technology for producing hydrogen peroxide at home and abroad is mainly an anthraquinone method. The 2-alkyl anthraquinone in the process is used as a 'carrier' of the process, and the quality and the yield of the hydrogen peroxide are directly influenced. The phthalic anhydride process is the primary method for producing 2-alkylanthraquinones, but this process suffers from serious contamination problems. 1.76 tons of anhydrous AlCl is required to be added for producing 1 ton of 2-ethyl anthraquinone₃And 4.2 tons of fuming H₂SO₄(20%) and the recovery of both is difficult. Therefore, it is very important to develop a green production process of 2-alkylanthraquinone from the viewpoint of environmental protection and clean production.

US 4255343 discloses a method for synthesizing 2-tert-amyl anthracene, which comprises uniformly mixing anthracene, trichlorobenzene and methanesulfonic acid under certain temperature and pressure conditions, and introducing olefin into the system to perform alkylation reaction with anthracene. The solid product was mainly the remaining anthracene and the series of alkyl anthracene products, with 42 wt% anthracene and 47 wt% 2-alkyl anthracene, with the remainder being anthracene disubstituted product and other by-products.

TW 200623958 discloses a method for alkylating anthracene by using ionic liquid catalysis, and the catalytic system of the alkylation reaction is a mixture containing 60-93.7 wt% of ionic liquid and 1-8 wt% of aluminum chloride. In the examples, BmimPF₆As solvent, and adding proper AlCl₃When the alkylation reaction of anthracene and tert-butyl chloride is catalyzed at 70 ℃, the yield of the product 2, 6-tert-butyl anthracene is 90%.

Perezromero et al used H₂O₂Oxidizing anthracene or 2-alkyl anthracene to prepare anthraquinone with Cu-containing Tp as catalyst^xCu (NCMe), after reacting for 2h at 80 ℃, the conversion rate of anthracene is 95%, and the selectivity of anthraquinone is 98%.

In US3953482 a process for the preparation of a catalyst using H is disclosed₂O₂A process for preparing 2-alkylanthraquinone by oxidizing 2-alkylanthraquinone. Using fatty alcohol as solvent, concentrated hydrochloric acid as catalyst and H₂O₂(60%) is an oxidant, and the reaction is carried out for 60min at the normal pressure of 40-100 ℃, so that a better reaction effect can be obtained. The conversion rate of the 2-pentylanthracene is 94 percent, and the selectivity of the 2-pentylanthraquinone is as high as 97 percent.

As can be seen, no complete set of process technology for preparing 2-alkylanthraquinone from anthracene is reported at present.

Disclosure of Invention

The invention aims to provide a novel method for separating 2-alkyl anthracene from a product containing alkyl anthracene and preparing the 2-alkyl anthraquinone by adopting a catalytic oxidation process on the basis of the prior art, namely an integral process for preparing the 2-alkyl anthracene by separating a reaction product containing the alkyl anthracene from anthracene serving as a raw material and preparing the 2-alkyl anthracene by oxidizing the 2-alkyl anthracene.

The invention provides a method for separating 2-alkyl anthracene from a product containing alkyl anthracene and preparing the 2-alkyl anthraquinone by adopting a catalytic oxidation process, wherein the preparation method comprises the following steps:

(1) preparing a reaction product containing an alkyl anthracene from an anthracene;

(2) separating the reaction product containing alkyl anthracene obtained from step (1), the separation method comprising: melting crystallization separation of anthracene and distillation separation of 2-alkyl anthracene;

(3) contacting the 2-alkyl anthracene obtained in the step (2) with an oxidizing agent, namely hydrogen peroxide, under oxidizing conditions and in the presence of an oxidizing reaction solvent and a catalyst, wherein the catalyst contains a carrier and a metal active component loaded on the carrier, and the metal active component is selected from one or more of alkaline earth metals, transition metals and lanthanide metals.

The whole technical route for preparing the 2-alkyl anthracene from the anthracene and preparing the 2-alkyl anthraquinone through catalytic oxidation is reasonable and feasible, and opens up a new direction for the green preparation of the 2-alkyl anthraquinone. The method provided by the invention can obviously reduce the operation difficulty in the separation process of the anthracene-alkyl anthracene product and improve the purity and the total yield of the intermediate target product 2-alkyl anthracene by a melt crystallization-distillation coupling separation technology.

In the method provided by the invention, the constructed 2-alkyl anthracene catalytic oxidation system is green and efficient, the catalyst is easy to separate and has high activity, and the 2-alkyl anthracene can be oxidized to prepare the 2-alkyl anthraquinone with high selectivity.

Preferably, in the method provided by the invention, a combined solvent system is adopted in the reaction process of preparing the anthraquinone by oxidizing the 2-alkyl anthracene, so that the oxidation reaction of the 2-alkyl anthracene can be enhanced by adjusting the property of the solvent, and the reaction selectivity and the product yield are improved.

In addition, the method provided by the invention also has the advantages of simple process, high efficiency and small pollution.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a flow diagram of a process for separating 2-alkylanthraquinone from an alkylanthraquinone-containing product and producing the 2-alkylanthraquinone using a catalytic oxidation process according to one embodiment of the present invention;

FIG. 2 is a diagram of an embodiment of the present invention for the isolation of an anthracene alkylation product, melt crystallization-multi-step vacuum distillation coupling process;

FIG. 3 is a diagram of an embodiment of the present invention for the isolation of an anthracene alkylation product, melt crystallization-multi-step vacuum distillation coupling process;

FIG. 4 is a flow diagram of the melt crystallization step in the present invention providing for the isolation of the anthracene alkylation product, melt crystallization-vacuum distillation process.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, 2-alkylanthraquinone means 2-alkyl-9, 10-anthraquinone, hereinafter referred to as 2-alkylanthraquinone.

According to the invention, the method for separating 2-alkyl anthracene from the product containing alkyl anthracene and preparing 2-alkyl anthraquinone by adopting catalytic oxidation process comprises the following steps:

(1) preparing a reaction product containing an alkyl anthracene from an anthracene;

(2) separating the reaction product containing alkyl anthracene obtained from step (1), the separation method comprising: melting crystallization separation of anthracene and distillation separation of 2-alkyl anthracene;

(3) contacting the 2-alkyl anthracene obtained in the step (2) with an oxidizing agent, namely hydrogen peroxide, under oxidizing conditions and in the presence of an oxidizing reaction solvent and a catalyst, wherein the catalyst contains a carrier and a metal active component loaded on the carrier, and the metal active component is selected from one or more of alkaline earth metals, transition metals and lanthanide metals.

According to the present invention, the starting material anthracene can be reacted to produce an anthracene containing an alkyl group. The method of producing an alkyl anthracene-containing reaction product from anthracene can be any single reaction or a combination of multiple steps to introduce an alkyl group into an anthracycline to produce an alkyl anthracene. Substances containing anthracene ring structures in the reaction products obtained in the step (1) comprise residual anthracene, 2-alkyl anthracene and other series alkyl anthracene products. It is well known to those skilled in the art that, depending on the reaction method, if the starting anthracene is not completely converted, the reaction product may contain residual anthracene. If the alkyl anthracene is not a single species, the alkyl anthracene may also be a mixture. Therefore, the production of alkyl anthracene-containing reaction products from a starting anthracene typically contains anthracene, 2-alkyl anthracene, and other series of alkyl anthracene products.

According to one embodiment of the present invention, as shown in fig. 1, the method for preparing a reaction product containing an alkyl anthracene from anthracene in step (1) includes: the alkylation reaction is carried out by contacting anthracene with an alkylating agent under alkylation conditions and in the presence of an alkylation solvent and a catalyst.

The mode of contacting anthracene with an alkylating agent and a catalyst according to the present invention can be any of various modes capable of producing alkyl anthracene by alkylation of anthracene. Preferably, for more complete reaction, the contacting is carried out in the following manner: the raw material liquid containing anthracene, catalyst and alkylation reaction solvent is contacted with alkylation reagent to make alkylation reaction.

According to the present invention, the conditions and methods of the anthracycline reaction in step (1) may be performed in a manner conventional in the art.

According to the present invention, in step (1), the alkylating agent may be any alkylating agent known to those skilled in the art capable of introducing an alkyl group into an anthracycline to prepare an alkyl anthracene, for example, the alkylating agent may be one or more of an olefin, an alcohol, a halogenated hydrocarbon, and an ether having 2 to 8 carbon atoms, preferably one or more of an olefin, an alcohol, a halogenated hydrocarbon, and an ether having 4 to 6 carbon atoms, and more preferably a monoolefin having 4 to 6 carbon atoms.

According to the invention, in step (1), the alkylating agent is used in an amount that enables the introduction of alkyl groups into the anthracycline to produce alkyl anthracenes, preferably in a molar ratio of anthracene to alkylating agent of from 0.2:1 to 20:1, more preferably from 0.5:1 to 5: 1.

According to the present invention, in the step (1), the alkylation reaction solvent is an inert organic solvent capable of dissolving anthracene. Specifically, the alkylation reaction solvent is a solvent having a dielectric constant of 1 to 10 at 20 ℃, and more specifically, the alkylation reaction solvent is C₆Above, preferably C₆-C₁₂And one or more of paraffins, naphthenes, and aromatics. Wherein the aromatic hydrocarbon is substituted or unsubstituted, preferably one or more of mono-or multi-substituted benzene; more preferably one or more of benzene multi-substituted compounds, the substituent is C₁-C₄And one or more of an alkyl group and a halogen element. Further preferably, the alkylation reaction solvent is one or more of polyalkyl substituents of benzene. Most preferably, the alkylation reaction solvent is selected from one or more of 1,3, 5-trimethylbenzene, 1,2,3, 5-tetramethylbenzene, 1,3,4, 5-tetramethylbenzene, 1,3,5, 6-tetramethylbenzene, and 2,3,5, 6-tetramethylbenzene. The amount of the alkylation reaction solvent is only required to ensure that the anthracene can be fully dissolved so as to achieve the effect of providing a good reaction medium. Preferably, the anthracene is present in an amount of from 5 to 60 weight percent, preferably from 8 to 50 weight percent, based on the total weight of anthracene and alkylation reaction solvent.

According to the present invention, in the step (1), the mode of contacting the anthracene with the alkylating agent under the alkylation conditions and in the presence of the alkylation reaction solvent and the catalyst is not particularly limited, and preferably, in order to ensure that the alkylation reaction can be carried out more favorably, the anthracene, the catalyst and the alkylation reaction solvent are prepared as a raw material solution of the anthracene-catalyst-alkylation reaction solvent, and then the alkylating agent is added to carry out the alkylation reaction. Preferably, the preparation temperature of the raw material liquid of the anthracene-catalyst-alkylation reaction solvent is 100-250 ℃, more preferably 120-200 ℃.

According to the present invention, in step (1), the alkylation reaction conditions generally comprise: the reaction temperature can be 100-250 ℃, preferably 120-200 ℃; the reaction time can be 0.01-48h, preferably 0.5-24 h; the reaction pressure may be from 0 to 1MPa, preferably from 0.05 to 0.5 MPa.

According to the present invention, in step (1), in order to enable the alkylation reaction to be more easily performed, the alkylation reaction is performed in the presence of a catalyst. In particular, the catalyst may be any form and kind of acid catalyst capable of catalyzing the alkylation of anthracene, for example, the catalyst is selected from one or more of liquid acids, preferably methanesulfonic acid and/or p-toluenesulfonic acid; the catalyst may also be used in an amount of 0.01 to 50 wt%, preferably 0.5 to 30 wt%, based on the total weight of the raw material solution containing anthracene, the alkylation reaction solvent and the catalyst, with reference to the amount conventionally used in the art.

According to the present invention, the process for preparing alkyl anthracene from raw material anthracene in step (1) requires the use of a catalyst, and the catalyst after reaction may be separated after step (1) and before step (2) by a separation method that is conventional in the art according to the nature of the catalyst.

According to physical analysis, the boiling point of anthracene is 340 ℃, and the alkyl anthracene product and the anthracene homologue have a boiling point difference, and the product can be separated by a reduced pressure distillation technology. But the technical difficulty is that the melting point of anthracene is as high as 215 ℃, anthracene with a high solidifying point is separated by adopting a vacuum distillation technology alone, the operation difficulty is high, once the pipeline has a problem in heat preservation, the phenomenon of blockage is easy to occur, and the continuous and stable operation of the process is seriously influenced. In addition, anthracene is very easily sublimed, and sublimation temperature is difficult to control, and the chance that the pipeline takes place to block up is showing to increase. Thus, it is impractical to use solely vacuum distillation techniques to achieve separation of the anthracene-alkyl anthracene product.

Therefore, the inventors of the present invention propose to separate anthracene and alkyl anthracene products using a melt crystallization-distillation separation method. The alkyl anthracene destroys the high regularity of an anthracene ring structure due to the existence of a side chain substituent group, so that the melting point of an alkyl anthracene product is obviously reduced, for example, the melting point range of a low-carbon alkyl anthracene product (1< the carbon number j1<8 of an alkyl side chain of anthracene) is 130-150 ℃, the melting point range of a high-carbon alkyl anthracene product (7< the carbon number j2<18 of an alkyl side chain of anthracene) is 150-190 ℃, the melting points are obviously lower than the melting point 215 ℃ of anthracene, and a large melting point difference exists between the alkyl anthracene and the anthracene. For this reason, the inventor of the present invention proposes to first use the melt crystallization technique to separate and remove the anthracene which has the highest melting point and is most difficult to separate by crystallization, and then use one or more reduced pressure distillation techniques to further separate the anthracene from the alkyl anthracene mixture with high boiling point according to the difference of the boiling points.

Based on this, according to the present invention, the reaction product containing alkyl anthracene obtained through step (1) contains anthracene and a series of alkyl anthracene products containing 2-alkyl anthracene; the step (2) comprises the following steps:

(2-2) heating the reaction product containing the alkyl anthracene obtained in the step (1) to a molten state, cooling and crystallizing, separating to obtain an anthracene crystal and a feed liquid containing a series of alkyl anthracene products of 2-alkyl anthracene, heating the anthracene crystal for sweating, and separating the sweating liquid and the anthracene crystal;

(2-3) separating 2-alkyl anthracene from a series of alkyl anthracene products containing 2-alkyl anthracene by one or more distillation steps.

According to one embodiment of the present invention, as shown in FIG. 4, the melt crystallization step can be carried out in a melt crystallization system in which the crystalline separation of anthracene from the reaction product mixture can be achieved. The melt crystallization system includes an intermediate melt tank and a melt crystallizer. The melted product containing anthracene and serial alkyl anthracene products heated and melted in the distillation tower is sent into an intermediate melting tank and then is introduced into a melting crystallizer. The apparatus for implementing the melt crystallization process is a melt crystallizer, the crystallization process can be lamellar crystallization or suspension crystallization, and the operation mode can be batch operation or continuous operation, but the invention is not limited to the method, but the batch operation lamellar crystallization mode is more preferable. The temperature increase and decrease in the melt crystallizer is achieved by introducing a heat exchange medium into the melt crystallizer. After the heated and melted material enters the melting crystallizer, the cooling medium is used for cooling, so that the anthracene with a high melting point is crystallized and separated out, and further, the separation of the anthracene and a series of alkyl anthracene products is realized.

According to the present invention, in the melt crystallization step of (2-2), in order to better achieve the crystal separation of anthracene, the melting temperature is controlled to 200-270 ℃, preferably 210-250 ℃.

According to the invention, the melt crystallization process essentially comprises three steps of cooling crystallization, sweating and preferably warming remelting of the anthracene crystals.

According to the present invention, the temperature for cooling crystallization can be 180-210 ℃, preferably 190-200 ℃. In order to better realize the crystal separation of anthracene, the cooling rate of the cooling crystal can be 0.1-10 ℃/h, preferably 0.5-5 ℃/h, and the cooling crystallization time, namely the crystal growth time can be controlled to be 1-5h, preferably 1.5-4 h.

According to the present invention, in order to increase the crystallization rate, in the cooling crystallization process, it is preferable to further include a step of adding seed anthracene, which may be added in an amount according to the details of the cooling crystallization process, and it is further preferable to add the seed anthracene in an amount of 0.1 to 10% by weight, more preferably 0.2 to 5% by weight, based on the mass of the molten mixture.

According to the present invention, in order to further increase the purity of the crystalline anthracene, it is necessary to further perform a sweating operation on the anthracene crystal. After the crystal layer is formed, the temperature of the crystal layer is slowly close to the equilibrium temperature by controlling the rising rate of the temperature of the crystal layer, and the local crystal containing more impurities is low in melting point due to uneven distribution of the impurities in the crystal layer and can be firstly melted and separated from the crystal in a sweating mode.

According to the present invention, in the melt crystallization step, the temperature increase rate at which the anthracene crystal undergoes sweating is controlled to 0.1 to 8 deg.C/h, preferably 0.2 to 4 deg.C/h, from the viewpoint of further improving the purity of the crystal and the separation accuracy. The temperature raised to the temperature at which sweating stops cannot melt the crystallized anthracene crystal, and therefore, the temperature raised to the temperature at which sweating stops must be lower than the melting temperature of the anthracene crystal, preferably the temperature raised to the temperature at which sweating stops is 210 ℃ or lower, more preferably, the temperature raised to 5 to 15 ℃ higher than the cooling crystallization temperature, and the sweating stops below 210 ℃. The sweating end temperature may be 190-210 deg.C, more preferably 195-205 deg.C, under the principle of following the above-mentioned sweating stop temperature. In order to further increase the purity of the crystalline anthracene, the amount of perspiration can also be controlled so that the amount of perspiration is 5 to 40% by weight, more preferably 10 to 30% by weight, of the mass of the crystal.

According to the present invention, in order to further improve the separation accuracy, the collected sweat is recycled, that is, the sweat is recycled to the melting and crystallizing step, and the melting and cooling crystallization is carried out by heating together with the reaction product containing alkyl anthracene, that is, the mixture containing anthracene and the series of alkyl anthracene products.

According to the invention, after sweating is finished, the temperature of the separated anthracene crystal can be increased to over 215 ℃, and the crystal anthracene is collected and recycled after being completely melted into liquid.

After melt crystallization according to the process of the present invention, the non-crystallized material collected, i.e., the feed solution of the 2-alkyl anthracene-containing series of alkyl anthracene products consisting essentially of the series of alkyl anthracene products (substantially free of anthracene), is collected.

According to the invention, the boiling points of the serial alkyl anthracene products containing 2-alkyl anthracene are all higher than that of anthracene (340 ℃), so that the distillation technology is needed to further realize the purpose of serial alkyl anthracene product separation. Thus, 2-alkyl anthracenes can be separated from a series of alkyl anthracene products containing 2-alkyl anthracenes by one or more distillation steps.

According to the present invention, in the step (2-3), when the alkyl anthracene product of the series containing 2-alkyl anthracene is a mixture of two substances, or a mixture of three or more substances, the boiling point of 2-alkyl anthracene is the lowest or the highest; then a one-step distillation is performed to separate the 2-alkyl anthracene. In the step (2-3), when the serial alkyl anthracene products containing the 2-alkyl anthracene are a mixture of more than three substances, and the boiling point of the 2-alkyl anthracene is between the substance with the highest boiling point and the substance with the lowest boiling point in the mixture; a multi-step distillation is performed.

According to an embodiment of the present invention, in the step (2-3), the multi-step distillation method comprises:

mode 1: as shown in fig. 2, a feed liquid of a series of alkyl anthracene products containing 2-alkyl anthracene is subjected to first distillation and separated to obtain a distillate containing light component Cj 1-anthracene and a bottom product containing heavy component Cj 2-anthracene; subjecting the distillate containing the light component C1 j-anthracene to second distillation to obtain a distillate containing the light component Cj 3-anthracene and a bottom product containing the target product Ci-anthracene;

wherein, the light component Cj 1-anthracene is an alkyl anthracene product with the total carbon number j1 of an alkyl side chain being an integer which is more than 1 and less than j1 and less than i +1, the heavy component Cj 2-anthracene is an alkyl anthracene product with the total carbon number j2 of the alkyl side chain being an integer which is more than i and less than j2 and less than 41, and the light component Cj 3-anthracene is an alkyl anthracene product with the total carbon number j3 of the alkyl side chain being an integer which is more than 1 and less than j3 and less than i;

wherein, in the target product Ci-anthracene, i represents the total carbon number of an alkyl side chain, i is an integer of 4-7, the substitution position is at 2 position, namely 2-alkyl anthracene, and the total carbon number of the alkyl side chain is 4-7.

The conditions of the first distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-. More preferably, the pressure at the top of the column is 0.1 to 10KPa, the temperature at the bottom of the column is 210-340 ℃, the number of theoretical plates is 30 to 75, and the reflux ratio at the top of the column is 1 to 7. Further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 260 ℃ to 320 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 3. Under this operating condition, the bottoms were predominantly Cj 2-anthracene product (total alkyl side chain carbon number j2 is an integer of i < j2< 41), and the overheads were Cj 1-anthracene product (total alkyl side chain carbon number j1 is an integer of 1< j1< i + 1).

The conditions of the second distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-330 ℃, the number of theoretical plates is 20-90, and the reflux ratio at the top of the distillation tower is 0.5-8. More preferably, the pressure at the top of the column is from 0.1 to 10KPa, the temperature at the bottom of the column is from 200 ℃ to 310 ℃, the number of theoretical plates is from 30 to 75, and the reflux ratio at the top of the column is from 1 to 7. Further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 220-305 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 5. Under the operating conditions, the bottom product is Ci-anthracene (2-alkyl anthracene, the total carbon number of alkyl side chain is 4-7), and the overhead product is Cj 3-anthracene (the total carbon number of alkyl side chain j3 is an integer of 1< j3 < i).

For example, as shown in FIG. 2, the alkyl anthracene mixture is a continuous homolog mixture of C2-anthracene to C20-anthracene, while C5-anthracene is the isolated target product. Through the first distillation, light components including C2-anthracene to C5-anthracene are obtained at the top of the tower, and heavy components including C6-anthracene to C20-anthracene are obtained at the bottom of the tower. The mixture of C2-anthracene to C5-anthracene is subjected to second distillation, light components obtained at the top of the tower comprise the mixture of C2-anthracene to C4-anthracene, and a target product of C5-anthracene is obtained at the bottom of the tower.

Alternatively, the first and second electrodes may be,

mode 2: as shown in fig. 3, the feed liquid of the series alkyl anthracene product containing 2-alkyl anthracene is subjected to third distillation to obtain distillate containing light component Cm 1-anthracene and a bottom product containing heavy component Cm 2-anthracene; carrying out fourth distillation on the bottom product containing the heavy component Cm 2-anthracene to obtain a distillate containing the target product Ci-anthracene and a bottom product containing the heavy component Cm 3-anthracene;

wherein the light component Cm 1-anthracene is an alkyl anthracene product with the total carbon number m1 of an alkyl side chain being an integer of more than 1 and less than m and i, the heavy component Cm 2-anthracene is an alkyl anthracene product with the total carbon number m2 of the alkyl side chain being an integer of more than i and less than m2 and less than 41, and Cm 3-anthracene is an alkyl anthracene product with the total carbon number m3 of the alkyl side chain being an integer of more than i and less than m3 and less than 41;

wherein, in the target product Ci-anthracene, i represents the total carbon number of an alkyl side chain, i is an integer of 4-7, the substitution position is at 2 position, namely 2-alkyl anthracene, and the total carbon number of the alkyl side chain is 4-7.

The conditions of the third distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-. More preferably, the pressure at the top of the column is 0.1 to 10KPa, the temperature at the bottom of the column is 210-340 ℃, the number of theoretical plates is 30 to 75, and the reflux ratio at the top of the column is 1 to 7. Further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 260 ℃ to 320 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 3. Under this operating condition, the bottoms product was predominantly Cm 2-anthracene product (total alkyl side chain carbon number m2 is an integer from i-1 < m 2< 41), and the overhead product was Cm 1-anthracene product (total alkyl side chain carbon number m1 is an integer from 1< m < i).

The conditions of the fourth distillation include: the pressure at the top of the distillation tower is 0.01-20KPa, the temperature at the bottom of the distillation tower is 180-330 ℃, the number of theoretical plates is 20-90, and the reflux ratio at the top of the distillation tower is 0.5-8. More preferably, the pressure at the top of the column is from 0.1 to 10KPa, the temperature at the bottom of the column is from 200 ℃ to 310 ℃, the number of theoretical plates is from 30 to 75, and the reflux ratio at the top of the column is from 1 to 7. Further preferably, the pressure at the top of the distillation column is 0.5 to 2KPa, the temperature at the bottom of the distillation column is 220-305 ℃, the number of theoretical plates is 40 to 75, and the reflux ratio at the top of the distillation column is 1 to 5. Under the operating conditions, the overhead product is Ci-anthracene (2-alkyl anthracene, the total carbon number of the alkyl side chain is 4-7) which is the target product, and the bottom product is Cm 3-anthracene (the total carbon number of the alkyl side chain is m3 which is an integer of i < m3 < 41).

For example, as shown in FIG. 3, the alkyl anthracene mixture is a continuous homolog mixture of C2-anthracene to C20-anthracene, while C5-anthracene is the isolated target product. Through the third distillation, light components including C2-anthracene to C4-anthracene are obtained at the top of the tower, and heavy components including C5-anthracene to C20-anthracene are obtained at the bottom of the tower. And (3) carrying out fourth distillation on a mixture of C5-anthracene to C20-anthracene, obtaining a target product C5-anthracene at the tower top, and obtaining a heavy component from the tower bottom, wherein the heavy component comprises C6-anthracene to C20-anthracene.

According to the present invention, the specific operating conditions of each of the vacuum distillations in the multi-step vacuum distillations can be appropriately selected within the operating temperature and pressure ranges thereof according to the different distillation ranges of the overhead product and the bottom product in each vacuum distillation.

According to the present invention, the multi-step vacuum distillation may employ various vacuum distillation apparatuses known in the art, for example: a sieve tray column or a packed column, more preferably a packed column.

According to the present invention, depending on the process and operating conditions of the reaction of step (1), other substances having a boiling point lower than that of anthracene, such as reaction solvents and other by-products (e.g., alkylating agent remaining after the alkylation reaction), may be entrained or generated, and are referred to as light components. Therefore, the reaction product containing an alkyl anthracene obtained via step (1) also contains a reaction solvent. The method further comprises a step (2-1) of separating the reaction solvent before the separation of anthracene by melt crystallization and the separation of 2-alkyl anthracene by distillation. The method of separating the solvent may be removed using a separation method that is conventional in the art. Preferably, the reaction solvent in the mixed solution containing the alkyl anthracene product is separated by atmospheric distillation from the viewpoint of further improving the separation efficiency and simplifying the operation. According to a specific embodiment of the present invention, the separation method of (2-1) comprises: and (2) distilling the reaction product containing the alkyl anthracene obtained in the step (1) in a distillation tower to obtain a distillate containing the reaction solvent and a tower bottom product containing anthracene and a series of alkyl anthracene products containing 2-alkyl anthracene. In addition, the separated reaction solvent may be recycled or collected for disposal as required for the reaction. In addition, other by-product separation methods can also be in the separation of anthracene alkyl anthracene before separation, can pass through conventional separation methods to remove, such as distillation.

Preferably, in the step (2-1), the distillation conditions include: the bottom temperature of the distillation column is 100-300 ℃, preferably 150-200 ℃, and the pressure at the top of the distillation column is normal pressure.

According to the invention, the intermediate product 2-alkyl anthracene is obtained by separation, and can be used for preparing 2-alkyl anthraquinone through reaction. According to the present invention, in the step (3), the 2-alkylanthraquinone is produced from the 2-alkylanthraquinone obtained through the step (2) by subjecting the 2-alkylanthraquinone to an oxidation reaction to produce the 2-alkylanthraquinone. Specifically, in the step (3), the process for producing 2-alkylanthraquinone from 2-alkylanthraquinone obtained via the step (2) comprises: contacting the 2-alkyl anthracene obtained in the step (2) with an oxidizing agent, namely hydrogen peroxide, under oxidizing conditions and in the presence of an oxidizing reaction solvent and a catalyst, wherein the catalyst contains a carrier and a metal active component loaded on the carrier, and the metal active component is selected from one or more of alkaline earth metals, transition metals and lanthanide metals.

According to the invention, in the step (3), the oxidizing agent hydrogen peroxide is combined with the supported catalyst to prepare the 2-alkylanthraquinone through high-selectivity oxidation of the 2-alkylanthraquinone, the oxidation system is simple and efficient, and the catalyst is easy to recover and has high activity.

Preferably, in step (3), the metal active component in the catalyst is selected from IVB groupA group VB, group VIB, group VIIB, group VIII metal, and a lanthanide metal, more preferably a combination of a lanthanide metal and at least one metal selected from the group consisting of group IVB, group VB, group VIB, group VIIB and group VIII metals. Specifically, the group IVB metal can be Ti and Zr, the group VB metal can be V, Nb and Ta, the group VIB metal can be Cr, Mo and W, the group VIIB metal can be Mn and Re, the group VIII metal can be Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, and the lanthanide metal can be La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Further preferably, the metal active component is selected from one or more of Ti, Zr, V, Cr, Mo, Mn, Ru and La, most preferably La in combination with at least one selected from V, Ti, Zr, Cr, Mn, Ru and Mo. The carrier in the catalyst can be selected from one or more of refractory inorganic oxide and molecular sieve, and is preferably refractory inorganic oxide. The heat-resistant inorganic oxide may be one or more selected from silica, magnesia and a silicon-aluminum composite oxide, wherein in the silicon-aluminum composite oxide, SiO is calculated as an oxide₂May be contained in an amount of 0.01 to 70% by weight, preferably 5 to 40% by weight, Al₂O₃The content of (B) may be 30 to 99.9% by weight, preferably 60 to 95% by weight.

The content of the carrier and the metal active component in the catalyst is not particularly limited, and the content of the carrier and the content of the metal active component in the catalyst are subject to the catalytic action. More preferably, the active metal component is present in an amount of from 0.01 to 40 wt%, more preferably from 0.1 to 30 wt%, calculated as elemental content, based on the weight of the support in the catalyst. Further preferably, in order to further improve the catalytic performance of the catalyst, when the active metal component in the catalyst is a combination of a lanthanide metal and a transition metal, the mass ratio of the transition metal to the lanthanide metal is 1-20:1 in terms of the element content.

According to the present invention, the catalyst can be prepared by an impregnation method which is conventional in the art, and for example, a dry impregnation method (i.e., an equivalent-volume impregnation method) can be selected for preparation, or for example, an incipient wetness impregnation method can be selected for preparation. The specific method comprises the following steps: impregnating a support with a solution containing a soluble compound of a metal selected from one or more of alkaline earth metals, transition metals and lanthanoid metals, drying and calcining the impregnated support.

Wherein, when the metal in the metal active component is a plurality of elements, the method of impregnating the carrier with the solution containing the soluble compound of the metal can be carried out as follows: (1) the carrier may be impregnated after preparing a mixed solution of a solution of soluble compounds of a plurality of metals; (2) the support may also be impregnated sequentially with soluble compounds of the various metals (the order of impregnation of the support with solutions of soluble compounds of the various metals may be chosen arbitrarily).

According to the present invention, the conditions for impregnating the support with the solution containing the soluble compound of the metal generally include a temperature and a time, the impregnation temperature may be 0 to 100 ℃, preferably 20 to 80 ℃, and the impregnation time may be appropriately selected depending on the degree of dispersion of the soluble compound of the metal, and preferably, the impregnation time is 4 to 24 hours, more preferably 6 to 12 hours. Furthermore, the amount of solvent in the solution of the soluble compound containing the metal is such that, on the one hand, the compound of the metal active component is sufficiently dissolved in the solvent and, on the other hand, sufficient dispersion of the support is ensured, and preferably the amount of solvent in the solution of the soluble compound containing the metal is from 0.05 to 10ml, preferably from 0.1 to 5ml, based on 1g of the support. According to the present invention, the solvent in the solution may be selected from one or more of water, methanol, ethanol, isopropanol, butanol and pentanol.

According to the invention, the amount of support and soluble compound of the metal can be chosen within wide limits, preferably such that the content of active metal component, calculated as element, is from 0.01 to 40% by weight, more preferably from 0.1 to 30% by weight, based on the weight of support in the catalyst.

According to the invention, the soluble compound of the metal is a soluble compound of one or more metals selected from IVB group, VB group, VIB group, VIIB group, VIII group and lanthanide metals, and more preferably, the soluble compound of the metal is a soluble compound of one or more metals selected from Ti, Zr, V, Cr, Mo, Mn, Ru and La. In order to further improve the catalytic performance of the catalyst, the soluble compound of the metal is a combination of a soluble compound of a lanthanide metal and a soluble compound of at least one metal selected from group ivb, vb, vib, viib and viii metals, most preferably a combination of a soluble compound of La and a soluble compound of at least one metal selected from V, Ti, Zr, Cr, Mn, Ru and Mo.

According to the present invention, the soluble metal compound is generally a water-soluble metal compound, and specifically for example, the soluble metal compound of Ti, Zr, V, Cr, Mo, Mn, Ru, and La may be one or more of nitrate, chloride, ammonium salt, and the like of the metal; preferably one or more selected from the group consisting of titanium trichloride, zirconium nitrate, ammonium metavanadate, ammonium chromate, ammonium molybdate, manganese nitrate, rhodium trichloride and lanthanum nitrate.

According to the present invention, after impregnating the support with the solution containing the soluble compound of the metal, the conditions for drying the support may be conventional drying conditions, for example, the drying temperature may be 90 to 125 ℃ and the drying time may be 1 to 12 hours.

According to the present invention, the conditions for impregnating the support with the solution containing the soluble compound of the metal and then calcining the dried support generally include a calcination temperature and a calcination time, the calcination temperature may be 300-700 ℃, and the duration of the calcination may be selected depending on the calcination temperature and may be generally 2-6 hours. The calcination is generally carried out in an air atmosphere, which includes both a flowing atmosphere and a static atmosphere.

According to the present invention, in step (3), for convenience of operation, hydrogen peroxide as the oxidizing agent is preferably used in the form of an aqueous hydrogen peroxide solution, the concentration of which is not particularly limited and can be selected by referring to the routine in the art.

According to the invention, the amount of catalyst used in step (3) can be selected within wide limits, preferably from 0.01 to 50% by weight, preferably from 0.5 to 30% by weight, based on the total weight of catalyst and oxidation reaction solvent.

According to the present invention, in the step (3), the oxidation reaction solvent is an inert organic solvent capable of dissolving the 2-alkylanthracene.

According to a specific embodiment of the present invention, the oxidation reaction solvent is a solvent having a dielectric constant of greater than 2.8 at 20 ℃, preferably, the oxidation reaction solvent is a solvent having a dielectric constant of greater than 2.8 to less than or equal to 50 at 20 ℃; more preferably, the oxidation reaction solvent is one or more of aliphatic alcohol having 1 to 4 carbon atoms, tetrahydrofuran, acetone, N-alkyl substituted amide and N-alkyl pyrrolidone. Wherein the aliphatic alcohol having 1 to 4 carbon atoms may be a monohydric alcohol or a polyhydric alcohol. In the N-alkyl substituted amide, the number of alkyl substituents is 1-2, and each alkyl substituent is independently C₁-C₄Alkyl group of (1). Most preferably, the oxidation reaction solvent is selected from one or more of methanol, t-butanol, acetone, N-dimethylformamide, N-dimethylacetamide, N-dimethylpropionamide, N-methylpyrrolidone, and N-ethylpyrrolidone. The amount of the oxidation reaction solvent is only required to ensure that the 2-alkyl anthracene can be fully dissolved so as to achieve the effect of providing a good reaction medium. Preferably, the 2-alkylanthracene is present in an amount of 0.1 to 80 wt%, preferably 5 to 50 wt%, based on the total weight of the 2-alkylanthracene and the oxidation reaction solvent.

According to another embodiment of the present invention, the oxidation reaction solvent is a combination of a solvent A having a dielectric constant of 1 to 10 at 20 ℃ and a solvent B having a dielectric constant of more than 10 to 50 or less at 20 ℃. The inventors of the present invention have found that, in the oxidation reaction in step (3), a combination solvent of a solvent a having a dielectric constant of 1 to 10 at 20 ℃ and a solvent B having a dielectric constant of more than 10 to 50 or less at 20 ℃ is used as the oxidation reaction solvent, and that the solvent properties can be specifically controlled, and the dissolution of 2-alkylanthracene and the promotion of the oxidation reaction can be enhanced by solvation, and the conversion of 2-alkylanthracene can be improved.

According to the invention, preferably, the solvent A is C₆Above, more preferably C₆-C₁₂One or more of paraffins, naphthenes and aromatics; wherein the aromatic hydrocarbon is substituted or unsubstituted, preferably one or more of monobasic or polybasic substituted substances of benzene, more preferably one or more of polybasic substituted substances of benzene, and the substituted group is preferably C₁-C₄And one or more of an alkyl group and a halogen element. Further preferably, the solvent A is one or more of polyalkyl substituents of benzene, and most preferably, the solvent A is one or more selected from 1,3, 5-trimethylbenzene, 1,2,3, 5-tetramethylbenzene, 1,3,4, 5-tetramethylbenzene, 1,3,5, 6-tetramethylbenzene, and 2,3,5, 6-tetramethylbenzene.

According to the invention, the solvent B is preferably an N-alkyl-substituted amide in which the number of alkyl substituents is from 1 to 2 and each alkyl substituent is independently C₁-C₄Alkyl groups of (a); more preferably, the solvent B is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide and N, N-dimethylpropionamide, and most preferably, the solvent B is N, N-dimethylformamide.

According to the invention, in step (3), in order to better achieve the invention purpose of enhancing the oxidation reaction by regulating the solvent property, the volume ratio of the solvent A to the solvent B is 0.01-100, and more preferably 0.05-10.

According to the second embodiment, the oxidation reaction solvent is used in the step (3) in an amount sufficient to ensure that the 2-alkylanthracene is sufficiently soluble to provide a good reaction medium. Preferably, the 2-alkylanthracene is present in an amount of 0.1 to 80 wt%, preferably 5 to 50 wt%, based on the total weight of the 2-alkylanthracene and the oxidation reaction solvent.

According to the present invention, the mode of contacting the 2-alkylanthracene with the oxidizing agent and the catalyst may be various modes capable of achieving the oxidation production of the 2-alkylanthracene to obtain the 2-alkylanthracene. Preferably, for more complete reaction, the contacting is carried out in the following manner: a raw material liquid containing a 2-alkylanthracene, a catalyst and an oxidation reaction solvent is brought into contact with an oxidizing agent to carry out an oxidation reaction.

According to the present invention, in step (3), the conditions and method of the oxidation reaction may be performed in a manner conventional in the art, except for the combination of the above-mentioned hydrogen peroxide oxidizing agent with a specific catalyst.

According to the present invention, in step (3), the oxidizing agent is used in an amount that enables oxidation of 2-alkylanthracene to produce 2-alkylanthracene, preferably in a molar ratio of the oxidizing agent to 2-alkylanthracene of from 0.01:1 to 100:1, more preferably from 1:1 to 50: 1.

According to the present invention, in step (3), the oxidation reaction is generally carried out under conditions including: the reaction temperature can be 10-200 ℃, and preferably 20-120 ℃; the reaction time can be 0.01-48h, preferably 0.5-24 h; the reaction pressure may be from 0 to 1MPa, preferably from 0 to 0.5 MPa.

According to the present invention, in the step (3), the preparation of 2-alkylanthraquinone from 2-alkylanthracene requires the use of a catalyst, and the catalyst after the reaction can be separated by a separation method which is conventional in the art according to the nature of the catalyst. The 2-alkylanthraquinone in the product is the target product, if other substances including the residual 2-alkylanthraquinone, solvent and generated by-products exist, the 2-alkylanthraquinone can be removed or purified respectively by adopting a conventional separation method or a combined separation method according to the difference of the properties of the substances.

The present invention will be described in detail below by way of examples.

The material composition data are obtained by chromatographic analysis.

The chromatographic analysis method comprises the following steps: agilent 7890A, column DB-1(50 m.times.0.25 mm. times.0.25 μm). Sample inlet temperature: 330 ℃, sample introduction: 0.2 mu L, the split ratio of 20:1, nitrogen as carrier gas, the flow rate of constant flow mode of 0.7mL/min, temperature programming: keeping the temperature at 110 ℃ for 10min, then increasing the temperature to 320 ℃ at the speed of 5 ℃/min, and keeping the temperature for 18 min. FID detector: temperature 350 ℃, hydrogen flow: 35mL/min, air flow: 350mL/min, tail gas blowing is nitrogen, and the flow is as follows: 25 mL/min.

Defining the conversion rate of anthracene as X in the alkylation reaction of step (1)₁The substance selectivity calculated on a molar basis is S (mol%). Using the colour of each substanceThe mass fraction is expressed as a percentage of the area of the peak, and the fraction W (mol%) of each substance based on the molar mass is calculated in combination with the molar mass.

AN is used for representing anthracene, Ci-AN represents 2-alkyl anthracene, and Cj-AN represents other alkyl anthracene.

The conversion of anthracene is shown in formula 1:

the 2-alkyl anthracene selectivity is shown in formula 2:

(II) in the separation process of the step (2), the purity B of a certain substance is the mass fraction of the substance, and the purity of the separated anthracene is B₁The purity of the separated 2-alkyl anthracene is B₂Calculated based on chromatographic data. The anthracene and alkyl anthracene mixture to be separated was chromatographed. Preparing an external standard analysis curve by adopting high-purity 2-alkyl anthracene and mesitylene, quantitatively calculating the content of 2-alkyl anthracene in the mixture of anthracene and 2-alkyl anthracene, and marking as W₀And g. The amount of 2-alkylanthracene actually isolated according to the process proposed by the invention is denoted W₁And g. The yield Y of the separation process is calculated as shown in formula 3 below.

(III) in the oxidation reaction of the step (3), the conversion rate of Ci-AN is defined as X₂The substance selectivity calculated on a molar basis is S (mol%). The mass fraction was expressed as a percentage of the chromatographic peak area of each substance, and the fraction W (% by mol) based on the molar amount of each substance was calculated in combination with the molar mass.

Ci-AN is adopted to represent 2-alkyl anthracene, Ci-AO is adopted to represent 2-alkyl anthraquinone, and Ci-X is adopted to represent other byproducts.

The 2-alkyl anthracene conversion is shown as formula 4:

the 2-alkylanthraquinone selectivity is shown in formula 5:

the following examples 1-17 are provided to illustrate the preparation of the 2-alkylanthraquinones provided by the present invention.