阅读说明：本技术 一种制备二元醇的方法 (Method for preparing dihydric alcohol ) 是由 刘菁 齐红彬 任海彧 因德拉·普拉卡什 石昱 于 2014-09-28 设计创作，主要内容包括：本发明公开一种制备二元醇的方法,该方法以糖和氢气为原料,在水中与催化剂接触制备二元醇,所采用的催化剂为复合催化剂,所述复合催化剂由主催化剂和助催化剂组成,其中,所述主催化剂为不溶于水的耐酸合金；所述助催化剂为可溶性钨酸盐和/或不可溶性钨化合物。本发明采用耐酸的、廉价的、稳定的不需要载体的合金为主催化剂,能在生产成本较低情况下保证二元醇的高收率。(The invention discloses a method for preparing dihydric alcohol, which takes sugar and hydrogen as raw materials, and contacts with a catalyst in water to prepare the dihydric alcohol, wherein the adopted catalyst is a composite catalyst, the composite catalyst consists of a main catalyst and a cocatalyst, and the main catalyst is acid-resistant alloy which is insoluble in water; the cocatalyst is soluble tungstate and/or an insoluble tungsten compound. The invention adopts acid-resistant, cheap and stable alloy without a carrier as a main catalyst, and can ensure high yield of the dihydric alcohol under the condition of lower production cost.)

1. A method for preparing dihydric alcohol is characterized in that sugar and hydrogen are used as raw materials, the raw materials are contacted with a catalyst in water to prepare the dihydric alcohol, the adopted catalyst is a composite catalyst, the composite catalyst consists of a main catalyst and a cocatalyst,

wherein the content of the first and second substances,

the main catalyst is acid-resistant alloy which is insoluble in water;

the cocatalyst is soluble tungstate and/or an insoluble tungsten compound.

2. The method of claim 1, wherein the glycol is ethylene glycol.

3. The method for producing a diol according to claim 2, wherein the reaction system has a pH of 1 to 7; more preferably, the pH of the reaction system is 3 to 6.

4. The method for producing diol according to claim 1 or 2, wherein the saccharide is one or more selected from the group consisting of five-carbon monosaccharides, disaccharides, and oligosaccharides, six-carbon monosaccharides, disaccharides, and oligosaccharides, soluble five-carbon polysaccharides, and soluble six-carbon polysaccharides.

5. The method for preparing glycol according to claim 4, wherein the soluble five-carbon polysaccharide and the soluble six-carbon polysaccharide refer to a soluble five-carbon polysaccharide and a soluble six-carbon polysaccharide under the reaction conditions of the system.

6. The method of claim 4, wherein the initial source of the sugar is a sugar-based material, a starch-based material, a lignocellulose-based material, an industrial residue of cellulose-based material, or a polysaccharide material; more preferably, the sugar-based material comprises sugar beet, sugar cane; the starch-based material comprises corn, wheat, barley, cassava; the lignocellulose-based substances comprise corn straws, corncobs, wheat straws, bagasse and wood; the cellulose industrial residue comprises corncob residue; the polysaccharide material comprises seaweed.

7. The method for producing glycol according to claim 1 or 2, wherein the sugar is reacted with hydrogen gas in the form of an aqueous sugar solution having a concentration of 5 to 60 wt%; more preferably, it is 20 to 50 wt%.

8. The method of claim 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, and aluminum.

9. The method of claim 8, wherein the acid-resistant alloy comprises, in parts by weight, 10-90 parts nickel, 1-5 parts rare earth element, 1-60 parts tin, and 5-9 parts aluminum.

10. The method of claim 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, and tungsten.

Technical Field

The present application is a divisional application of chinese patent application 201410512704.7. The present invention relates to a process for the preparation of glycols.

Background

Ethylene glycol has a large application market as an important monomer for bottle-grade polyester and fiber-grade polyester. Propylene glycol can be widely used in the food, pharmaceutical and cosmetic industries. For a long time, the production of glycols such as ethylene glycol, propylene glycol and the like is mainly obtained by using petroleum-based olefin as a raw material through two-step methods such as oxidation and hydration. However, with the gradual depletion of petroleum resources, the utilization of renewable raw materials for the production of glycols has great commercial prospects.

Disclosure of Invention

The invention aims to provide a method for preparing dihydric alcohol. The invention adopts acid-resistant, cheap and stable alloy without a carrier as a main catalyst to prepare the dihydric alcohol.

The invention adopts the following technical scheme:

a process for preparing dihydric alcohol features that the sugar and hydrogen are used as raw materials, and the raw materials are contacted with catalyst in water to prepare dihydric alcohol, the catalyst used is composite catalyst composed of primary catalyst and cocatalyst,

wherein the content of the first and second substances,

the main catalyst is acid-resistant alloy which is insoluble in water;

the cocatalyst is soluble tungstate and/or an insoluble tungsten compound.

Preferably, the glycol is ethylene glycol.

The invention adopts acid-resistant, cheap, stable and carrier-free water-insoluble acid-resistant alloy as a main catalyst, and the acid-resistant, cheap and stable water-insoluble acid-resistant alloy is matched with a promoter of soluble tungstate and/or an insoluble tungsten compound to be used as a composite catalyst for catalyzing sugar to prepare the dihydric alcohol, so that the yield of the dihydric alcohol, particularly the ethylene glycol, can be ensured under the condition of low production cost. The water-insoluble acid-resistant alloy of the invention is stable under acidic conditions, and does not need to add alkali in a reaction system to neutralize acid generated by hydrolysis of sugar. When the method is applied to industrial continuous production, the use of the acid-resistant alloy main catalyst is particularly important for long-term and stable operation of a system and control of production cost.

Preferably, when the ethylene glycol is prepared by the method, the pH value of the reaction system is 1-7; more preferably, the reaction system has a pH of 3 to 6. By controlling the pH value of the system to be less than 7, the hydrolysis side reaction of the raw material sugar in the reaction process can be avoided, the consumption of the raw material sugar in the production of the ethylene glycol is reduced, the service life of the catalyst is ensured, the use cost of the catalyst can be reduced, the long-term continuous operation stability of the reaction system is ensured, and meanwhile, the yield of the ethylene glycol is high, and the yield of the organic acid and the polymer is low. If the acid generated during the reaction is insufficient to maintain a low pH, an organic acid or an inorganic acid such as lactic acid, formic acid, acetic acid, etc. may be added to the system to adjust the pH of the reaction system. Usually, an organic acid or an inorganic acid is added together with the raw material sugar.

Preferably, the sugar is selected from one or more of five-carbon monosaccharide, disaccharide and oligosaccharide, six-carbon monosaccharide, disaccharide and oligosaccharide, soluble five-carbon polysaccharide and soluble six-carbon polysaccharide. The original source of raw sugar includes, but is not limited to, sugar-based materials such as sugar beet, sugar cane, etc., starch-based materials such as corn, wheat, barley, cassava, etc., lignocellulose-based materials such as corn stover, corn cobs, wheat straw, bagasse, wood, etc., industrial residues of cellulose such as corn cob residues, etc., or polysaccharide materials including seaweed, etc. Herein, the soluble five-carbon and six-carbon polysaccharides refer to five-carbon and six-carbon polysaccharides that are soluble under the reaction conditions of the present invention, and not only to five-carbon and six-carbon polysaccharides that are soluble at normal temperature.

Preferably, the sugar reacts with hydrogen in the form of an aqueous sugar solution (sugar solution for short) having a concentration of 5-60 wt%. More preferably, it is 20 to 50 wt%. In a continuous operation, the sugar liquor may be fed continuously by a transfer pump. The invention ensures that the reaction system has smaller limit on the concentration of the raw material sugar by selecting a proper catalyst, can adopt high-concentration sugar liquid as the raw material, can greatly reduce the production cost of dihydric alcohol, particularly glycol, and realizes the large-scale and economic production of the dihydric alcohol.

Further, the acid-resistant alloy includes nickel, one or more rare earth elements, tin, and aluminum; the components are preferably 10-90 parts, 1-5 parts, 1-60 parts and 5-9 parts by weight respectively.

Herein, the rare earth element refers to a general term of 17 chemical elements having atomic numbers of 21, 39 and 57 to 71 in the IIIB group of the periodic system, and includes lanthanum (La), cerium (Ce), samarium (Sm), and the like.

More preferably, the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, and tungsten; the components are preferably 10-90 parts, 1-5 parts, 1-60 parts, 5-9 parts and 1-90 parts by weight respectively.

Further preferably, the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, tungsten and molybdenum, and the components are preferably 10-90 parts, 1-5 parts, 1-60 parts, 5-9 parts, 1-90 parts and 0.5-20 parts by weight respectively.

Most preferably, the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, tungsten, molybdenum, and boron or phosphorus, preferably 10-90 parts, 1-5 parts, 1-60 parts, 5-9 parts, 1-90 parts, 0.5-20 parts, and 0.01-5 parts, respectively, by weight.

Preferably, the soluble tungstate is one or more of ammonium tungstate, sodium tungstate and sodium phosphotungstate; the insoluble tungsten compound is tungsten trioxide and/or tungstic acid.

The main catalyst is mixed with water and then added into the reactor.

Preferably, the amount of said procatalyst is from 0.01 to 10 times the amount of sugar fed per hour.

Preferably, the reaction is in continuous mode.

Preferably, the supplementary amount of the main catalyst is as follows: the main catalyst is added in an amount of 0.01-5kg per 1000kg of sugar. The make-up of catalyst can be accomplished by discharging a portion of the old catalyst through a catalyst discharge valve (typically at the bottom of the reactor) and then making-up the same amount of fresh catalyst through a catalyst feed valve (typically at the bottom of the reactor).

The soluble cocatalyst can be added into the sugar solution firstly and then added into the reactor. Preferably, the soluble promoter is used in an amount of 0.01 to 5 wt% of the aqueous sugar solution. More preferably, it is 0.01 to 2 wt%. Most preferably, from 0.01 to 1 wt%.

The insoluble promoter may be added to the reactor along with the main catalyst. Preferably, the insoluble cocatalyst is used in an amount of 0.5-50 wt% of the main catalyst. More preferably, it is from 5 to 20% by weight.

Preferably, the reaction pressure of the reaction system is 5-12MPa, the reaction temperature is 150-260 ℃, and the reaction time is more than or equal to 10 min.

More preferably, the reaction pressure of the reaction system is 6-10MPa, the reaction temperature is 180-250 ℃, and the reaction time is 0.5-3 h. The reaction time is most preferably 0.5 to 2 hours.

Preferably, the reaction is carried out in a slurry bed reactor. In order to ensure the smooth reaction, the total volume of the reaction solution is not more than 80% of the volume of the reactor.

Preferably, the slurry bed reactor is provided with a filter therein for retaining an insoluble portion of the catalyst in the reactor without being carried away by the gas and the reaction liquid flowing out through the filter.

Before the reaction starts, adding a main catalyst into a slurry bed reactor, and respectively adding hydrogen and sugar solution into the reactor simultaneously by using a pump to react; the sugar and the main catalyst are supplemented in a continuous flowing state, and the reaction liquid continuously flows out from the reactor. Adding the cocatalyst into the reactor together with the sugar solution when the cocatalyst is a soluble tungsten compound; when it is an insoluble tungsten compound, it is added to the reactor simultaneously with the main catalyst. The reactor is internally provided with a filter. The filter can retain the catalyst, but the gas and the reaction liquid continuously flow out through the filter and enter the condenser for gas-liquid separation. Purifying the crude hydrogen to remove CO and CO₂，CH₄And the hydrogen gas is again purified and returned to the reactor. And (3) feeding the effluent flowing out of the condenser into a separation system, and separating to obtain water, ethylene glycol, propylene glycol, butanediol, glycerol, sorbitol, a cocatalyst and the like. The products such as ethylene glycol, propylene glycol, butanediol and the like can be obtained by purification by utilizing the prior art (such as rectification). The water, sorbitol, glycerol and cocatalyst which are dissolved in the reaction system are returned to the reactor for circulating reaction.

The invention has the following beneficial effects:

1. the catalyst of the invention is cheap and stable, and does not need a carrier.

2. The invention can select sugar solution with high concentration as raw material, and the production cost of dihydric alcohol, especially glycol, is low.

3. The method has high yield of the ethylene glycol.

The present application also relates to the following embodiments:

1. a method for preparing dihydric alcohol is characterized in that sugar and hydrogen are used as raw materials, the raw materials are contacted with a catalyst in water to prepare the dihydric alcohol, the adopted catalyst is a composite catalyst, the composite catalyst consists of a main catalyst and a cocatalyst,

wherein the content of the first and second substances,

the main catalyst is acid-resistant alloy which is insoluble in water;

the cocatalyst is soluble tungstate and/or an insoluble tungsten compound.

2. The method of preparing glycol according to embodiment 1, wherein the glycol is ethylene glycol.

3. The method for producing a diol according to embodiment 2, wherein the reaction system has a pH of 1 to 7; more preferably, the pH of the reaction system is 3 to 6.

4. The method for preparing diol according to embodiment 1 or 2, wherein the sugar is one or more selected from the group consisting of five-carbon monosaccharides, disaccharides and oligosaccharides, six-carbon monosaccharides, disaccharides and oligosaccharides, soluble five-carbon polysaccharides, and soluble six-carbon polysaccharides.

5. The method for producing glycol according to embodiment 4, wherein the soluble five-carbon polysaccharide and the soluble six-carbon polysaccharide refer to a soluble five-carbon polysaccharide and a soluble six-carbon polysaccharide under the reaction conditions of the system.

6. The method of preparing glycol according to embodiment 4, wherein the initial source of the sugar is a sugar-based material, a starch-based material, a lignocellulose-based material, an industrial residue of cellulose-based material, or a polysaccharide material; more preferably, the sugar-based material comprises sugar beet, sugar cane; the starch-based material comprises corn, wheat, barley, cassava; the lignocellulose-based substances comprise corn straws, corncobs, wheat straws, bagasse and wood; the cellulose industrial residue comprises corncob residue; the polysaccharide material comprises seaweed.

7. The method for producing glycol according to embodiment 1 or 2, characterized in that the sugar is reacted with hydrogen gas in the form of an aqueous sugar solution having a concentration of 5 to 60 wt%; more preferably, it is 20 to 50 wt%.

8. The method of preparing glycol according to embodiment 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin and aluminum.

9. The method of embodiment 8, wherein the acid-resistant alloy comprises, in parts by weight, 10-90 parts nickel, 1-5 parts rare earth element, 1-60 parts tin, and 5-9 parts aluminum.

10. The method of preparing glycol according to embodiment 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, and tungsten.

11. The method of embodiment 10, wherein the acid-resistant alloy comprises, by weight, 10-90 parts nickel, 1-5 parts rare earth element, 1-60 parts tin, 5-9 parts aluminum, and 1-90 parts tungsten.

12. The method of preparing glycol according to embodiment 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, tungsten, and molybdenum.

13. The method of embodiment 12, wherein the acid-resistant alloy comprises, in parts by weight, 10-90 parts nickel, 1-5 parts rare earth element, 1-60 parts tin, 5-9 parts aluminum, 1-90 parts tungsten, and 0.5-20 parts molybdenum.

14. The method of embodiment 1 or 2, wherein the acid-resistant alloy comprises nickel, one or more rare earth elements, tin, aluminum, tungsten, molybdenum, and boron or phosphorus.

15. The method of preparing diol according to embodiment 14, wherein the acid-resistant alloy comprises, in parts by weight, 10 to 90 parts of nickel, 1 to 5 parts of rare earth element, 1 to 60 parts of tin, 5 to 9 parts of aluminum, 1 to 90 parts of tungsten, 0.5 to 20 parts of molybdenum, and 0.01 to 5 parts of boron or phosphorus.

16. The method for producing a diol according to any one of embodiments 8 to 15, wherein the rare earth element refers to the general name of 17 chemical elements having atomic numbers 21, 39 and 57 to 71 in group iiib of the periodic system.

17. The method according to embodiment 1 or 2, wherein the soluble tungstate is one or more of ammonium tungstate, sodium tungstate, and sodium phosphotungstate.

18. The method for producing a diol according to embodiment 1 or 2, characterized in that the insoluble tungsten compound is tungsten trioxide and/or tungstic acid.

19. The method for producing glycol according to embodiment 1 or 2, wherein the amount of the main catalyst is 0.01 to 10 times the amount of the sugar fed per hour.

20. The method for preparing glycol according to embodiment 7, wherein the soluble co-catalyst is used in an amount of 0.01 to 5 wt% of the sugar aqueous solution; more preferably, from 0.01 to 2 wt%; most preferably, from 0.01 to 1 wt%.

21. The method for preparing glycol according to embodiment 1 or 2, wherein the insoluble co-catalyst is used in an amount of 0.5 to 50 wt% of the main catalyst; more preferably, it is from 5 to 20% by weight.

22. The method for preparing glycol according to embodiment 1 or 2, wherein the reaction pressure of the reaction system is 5-12MPa, the reaction temperature is 150-260 ℃, and the reaction time is not less than 10 min.

23. The method for preparing glycol according to embodiment 22, wherein the reaction pressure of the reaction system is 6-10MPa, the reaction temperature is 180-250 ℃, and the reaction time is 0.5-3h, preferably 0.5-2 h.

24. The method for preparing glycol according to embodiment 1 or 2, wherein the reaction is in a continuous mode.

25. The method for preparing diols according to embodiment 24, wherein the amount of the main catalyst added is: the main catalyst is added in an amount of 0.01-5kg per 1000kg of sugar.

26. The method for producing diols according to embodiment 1 or 2 is characterized in that the cocatalyst which has been dissolved in the reaction system is separated from the product and recycled.

27. The method for preparing glycol according to embodiment 1 or 2, characterized in that the reaction is carried out in a slurry bed reactor.

28. The method for preparing glycol according to embodiment 27, wherein the slurry bed reactor is provided with a filter for keeping an insoluble portion of the catalyst in the reactor without being carried away by the gas and the reaction liquid flowing out through the filter.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic flow diagram of the process of the present invention.

FIG. 2 is a graph of ethylene glycol yield over time for example 2.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

FIG. 1 is a schematic flow diagram of the process of the present invention.