KR102347393B1 - Method of Preparing Anhydrosugar Alcohols - Google Patents

Abstract

The present invention relates to a method for producing a high yield of anhydrosugar alcohol by simultaneously performing a reduced pressure reaction and reduced pressure distillation in the presence of a catalyst having excellent reaction activity under reduced pressure. Anhydrosugar alcohol can be prepared in excellent yield.

Description

Method of preparing anhydrosugar alcohols {Method of Preparing Anhydrosugar Alcohols}

The present invention relates to a method for producing anhydrosugar alcohol, and more particularly, to a method for producing anhydrosugar alcohol in high yield by simultaneously performing a reduced pressure reaction and reduced pressure distillation in the presence of a catalyst having excellent reaction activity under reduced pressure conditions. .

Due to the depletion of traditional energy sources along with an increase in global energy demand, the current development of alternative energy is spurred. Among them, biomass is a renewable, quantitative biological resource that is receiving a lot of attention.

Among biomass-based industrial raw materials, isosorbide (C ₆ H ₁₀ O _{4 ) produced by dehydration of sorbitol (C 6} H ₁₄ O ₆ ) replaces bisphenol A (BPA, bisphenol A). It is in the spotlight as an eco-friendly material such as polycarbonate (PC, polycarbonate), a monomer for epoxy, or a raw material for an eco-friendly plasticizer. That is, child carbide is a material that can be obtained through a simple dehydration process of sorbitol, and is attracting attention as a monomer necessary for the synthesis of next-generation high-performance, eco-friendly materials that can replace conventional polymer products. A lot of research is going on.

In general, when eco-friendly raw materials are used, physical properties are inferior to those of petrochemical-based raw materials, whereas isosorbide has the advantage of being environmentally friendly and showing superior characteristics than existing petrochemical-based raw materials. In addition, child carbide can be used as an additive to make plastic stronger and more durable, and child carbide combined with nitrate is also used as a heart disease treatment.

Sorbitol is produced when D-glucose, which has undergone a pretreatment process in biomass, is hydrogenated under a catalyst. This sorbitol is subjected to double dehydration to produce isosorbide. This cyclization reaction is affected by various reaction conditions such as temperature, pressure, solvent, and catalyst.

The method for producing child carbide is prepared by performing a dehydration reaction using an inorganic acid such as sulfuric acid or hydrochloric acid as a catalyst. Inorganic acids, such as hydrochloric acid or sulfuric acid, can be relatively inexpensive and easily produced anhydrosugar alcohol, but there is a problem in that the purification yield is lowered due to the high production of polymers as by-products.

On the other hand, for the efficiency of the separation process as well as the reaction, the development of a manufacturing method capable of simultaneously performing the reaction and distillation is required. It is disclosed in US Patent No. 6,864,378 and Korean Patent Publication No. 2013-0103059. U.S. Patent No. 6,864,378 discloses a process in which excess water compared to sorbitol is simultaneously introduced into the reactor, and the product and excess water are recovered to the upper part of the reactor. In this case, since it is a process of raising the temperature and vaporizing the water input in excess, there is a disadvantage in that the operating cost is greatly increased. Korean Patent Application Laid-Open No. 2013-0103059 discloses the use of a sulfated metal oxide solid acid catalyst in order to compensate for the limitation in the catalytic role due to evaporation of sulfuric acid when the sulfuric acid catalyst is used. In this case, since an expensive catalyst is used and the reaction proceeds in a hetero phase by using a solid acid catalyst, the contact efficiency between the catalyst and sorbitol is low, and the reaction time is 2 to 8 hours. There is a problem in that the operating cost increases. Therefore, an economical and efficient manufacturing method with a high conversion rate and yield of child carbide while reducing costs has been required, and if a mass production process is prepared accordingly, the range of demand as an industrial product can be expanded.

Accordingly, the present inventors have excellent reaction activity under reduced pressure conditions similar to those for converting sorbitol to child carbide, and when selecting and using an effective catalyst having a boiling point high enough not to be included in the child carbide separated by vacuum distillation, It was confirmed that a high yield of child carbide can be produced by performing the reduced pressure reaction and reduced pressure distillation at the same time, thereby completing the present invention.

It is an object of the present invention to increase the yield of anhydrosugar alcohol by simultaneously performing the reduced pressure reaction and reduced pressure distillation by using a catalyst with excellent reaction activity, recovery rate and stability under conditions similar to the reduced pressure conditions for dehydrating sugar alcohol to anhydrosugar alcohol. To provide a method for producing anhydrosugar alcohol.

In order to achieve the above object, the present invention provides a method for preparing anhydrosugar alcohol comprising the step of dehydrating the sugar alcohol at a pressure of 1 to 20 mmHg in the presence of a catalyst represented by Formula 1:

[Formula 1]

In Formula 1, at least two of R1 to R8 are a sulfone group (-SO ₃ H), and R1 to R8 other than the sulfone group are each independently hydrogen, a hydroxyl group, an amino group, a C _{1 to 10} alkyl group, C _{6 to 10} An aryl group or a C _1-10 alkoxy group.

Since the method for producing anhydrosugar alcohol according to the present invention uses a catalyst having a higher boiling point than sorbitol as well as child carbide, the produced child carbide can be recovered by distillation at the same time as the reaction, so the process is simple and the overall yield has the effect of improving

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is those well known and commonly used in the art.

In preparing child carbide from sorbitol, in order to simultaneously perform the reduced pressure reaction and reduced pressure distillation, i) the reaction temperature at which child carbide is optimally produced and ii) the temperature at which the produced child carbide can be distilled is as high as possible. should be similar On the other hand, the production temperature of child carbide is affected by the catalyst, and the distillation temperature of child carbide is affected by reduced pressure conditions, but is known to be distilled at 150 ~ 200 ° C. at a pressure of approximately 1 ~ 10 mmHg.

Therefore, it is important to select a catalyst having excellent reaction activity under conditions similar to the reduced pressure conditions, and the boiling point (b.p) of the catalyst is preferably as high as possible in order to prevent the catalyst from being included in the child carbide separated by vacuum distillation.

Therefore, when the novel catalyst according to the present invention is used, a reduced pressure reaction and reduced pressure distillation can be performed simultaneously to produce a high yield of child carbide, and the temperature (120 to 150) that promotes the production of 1,4-sorbitan ℃) and the distillation temperature (170 ℃ or more) of the produced carbide was confirmed to be suitable for an operation method that can satisfy both.

Accordingly, the present invention, in one aspect, relates to a method for producing anhydrosugar alcohol comprising the step of dehydrating the sugar alcohol at a pressure of 1 to 20 mmHg in the presence of a catalyst represented by the formula (1):

[Formula 1]

In Formula 1, at least two of R1 to R8 are a sulfone group (-SO ₃ H), and R1 to R8 other than the sulfone group are each independently hydrogen, a hydroxyl group, an amino group, a C _{1 to 10} alkyl group, C _{6 to 10} An aryl group or a C _1-10 alkoxy group.

The above catalyst is an acid catalyst having a structure that has never been used as a catalyst for producing child carbide, and has a high boiling point and many sulfone groups. to be.

In the present invention, preferably, two of R1 to R8 in Formula 1 are a sulfone group (-SO ₃ H), and R1 to R8 other than the sulfone group may be hydrogen, a hydroxyl group, or an amino group. Representative compounds include 1,5-naphthalenedisulfonic acid (1,5-NDSA), 2-amino-1,5-naphthalenedisulfonic acid (2-amino-1,5-naphthalenedisulfonic acid), 7-amino-1,3-naphthalenedisulfonic acid, 2,6-naphthalenedisulfonic acid, 1,3,6-naphthalenetrisulfonic acid (1,3,6-naphthalenetrisulfonic acid), 4-hydroxy-2,7-naphthalenedisulfonic acid (4-hydroxy-2,7-naphthalenedisulfonic acid), 3-hydroxy-4-nitroso-2,7- 3-hydroxy-4-nitroso-2,7-naphthalenedisulfonic acid and 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid acid), but is not limited thereto.

In the method for producing anhydrosugar alcohol according to the present invention, a dehydration reaction is performed at a temperature of 150 to 200° C. and a pressure of 1 to 20 mmHg, and the anhydrosugar alcohol produced by the dehydration reaction is distilled and recovered at the same time as the reaction.

In addition, according to the conditions of the process in the present invention, after performing a dehydration reaction first, distillation may be additionally performed at a pressure of 1 to 20 mmHg.

If the reaction temperature is less than 150° C., the reaction rate is slowed and the reaction time is long, and the anhydrosugar alcohol produced by the dehydration reaction is not distilled at the same time as the reaction. When the reaction temperature exceeds 200° C., the carbonization reaction occurs rapidly and the reaction yield decreases. When the reaction pressure exceeds 20 mmHg, the reaction rate is slowed and the reaction time is long.

In view of the efficiency of the process, the smaller the amount of the catalyst added, the higher the economic efficiency. can When the amount of catalyst added is less than 0.1 parts by mol, there is a problem that the dehydration reaction takes too long, and when it exceeds 5 parts by mol, there is a problem in that the production of saccharide polymers as a by-product increases and the yield is lowered.

In the present invention, the sugar alcohol may be hexitol, and may be at least one selected from the group consisting of sorbitol, mannitol and iditol, preferably sorbitol, and the anhydrous sugar alcohol is isosorbide, isomann It may be need, isoidide, etc., preferably isosorbide.

The method for producing anhydrosugar alcohol according to the present invention may be carried out in a batch or continuous manner. It may be carried out in a Continuous Stirred Tank Reactor (CSTR), a Plug Flow Reactor (PFR) or a Batch Reactor (BR).

In addition, the method for producing anhydrosugar alcohol according to the present invention may further include separation and/or purification of the product after preparing the anhydrosugar alcohol. As a product separation and purification process, distillation, crystallization, adsorption processes, etc. may be used alone or in combination of two or more.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples.

[Example]

Example One

70 g (0.38 mol) of sorbitol (D-sorbitol, Aldrich) was put into a 250 mL round bottom flask (RBF), and the reaction temperature was raised to 180° C. to dissolve sorbitol, and then 1,5-naphthalenedisulfonic acid 0.6 mmol (1,5-naphthalenedisulfonic acid, 1,5-NDSA, Aldrich) was added and the reaction pressure was reduced to 10 mmHg with stirring. The child carbide produced during the reaction for 1 hour was recovered by distillation to the outside of the reactor at the same time as the reaction.

The obtained reaction product was diluted 20-fold with water and analyzed by high-performance liquid chromatography (HPLC, manufactured by Algilent, using Carbohydrate column).

Example 2

Example 1 was carried out in the same manner as in Example 1, except that the reaction was performed at a reaction temperature of 190°C instead of a reaction temperature of 180°C.

Example 3

Example 1 was carried out in the same manner as in Example 1, except that 1.2 mmol was added instead of 0.6 mmol of 1,5-naphthalenedisulfonic acid.

Example 4

Same as Example 1 except that 2-amino-1,5-naphthalenedisulfonic acid (2-amino-1,5-naphthalenedisulfonic acid, Aldrich Co.) was used instead of 1,5-naphthalenedisulfonic acid in Example 1 was carried out.

Example 5

Same as Example 1 except that 7-amino-1,3-naphthalenedisulfonic acid (7-amino-1,3-naphthalenedisulfonic acid, Aldrich) was used instead of 1,5-naphthalenedisulfonic acid in Example 1 was carried out.

comparative example One

Example 1 was carried out in the same manner as in Example 1, except that sulfonic acid was used instead of 1,5-naphthalenedisulfonic acid.

comparative example 2

Example 1 was carried out in the same manner as in Example 1, except that benzenesulfonic acid was used instead of 1,5-naphthalenedisulfonic acid.

The yields of the products according to Examples 1 to 5 and Comparative Examples 1 and 2 were calculated in the following manner and shown in Table 1.

mol% yield = number of moles of produced child sorbide / number of moles of sorbitol added X 100

catalyst reaction temperature
(℃) transference number
(mole%) Example 1 1,5-naphthalenedisulfonic acid 0.6 mmol 180 74.8 Example 2 1,5-naphthalenedisulfonic acid 0.6 mmol 190 74.3 Example 3 1,5-naphthalenedisulfonic acid 1.2 mmol 180 75.2 Example 4 2-amino-1,5-naphthalenedisulfonic acid 0.6 mmol 180 74.1 Example 5 7-amino-1,3-naphthalenedisulfonic acid
0.6mmol 180 74.2 Comparative Example 1 H ₂ SO ₄ 0.6 mmol 180 58 Comparative Example 2 Benzenesulfonic acid 0.6 mmol 180 29

As shown in Table 1, the yield of the child carbide prepared according to Examples 1 to 5 in which the reduced pressure distillation reaction was performed using the catalyst according to the present invention is superior to that when using the conventional acid catalyst sulfuric acid or benzenesulfonic acid. A yield of child carbide of up to 75.2 mol % of phosphorus was achieved.

As the specific parts of the present invention have been described in detail above, for those of ordinary skill in the art, it is clear that these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, it is intended that the substantial scope of the invention be defined by the claims and their equivalents.

Claims (7)

A method for producing anhydrosugar alcohol comprising the step of dehydrating the sugar alcohol at a pressure of 1 to 20 mmHg in the presence of a catalyst represented by the formula (1):
[Formula 1]

In Formula 1, at least two of R1 to R8 are a sulfone group (-SO ₃ H), and R1 to R8 other than the sulfone group are each independently hydrogen, a hydroxyl group, an amino group, a C _{1 to 10} alkyl group, C _{6 to 10} an aryl group or a C _1-10 alkoxy group,
The catalyst is 1,5-naphthalenedisulfonic acid (1,5-NDSA), 2-amino-1,5-naphthalenedisulfonic acid (2-amino-1,5-naphthalenedisulfonic acid), 7 -Amino-1,3-naphthalenedisulfonic acid (7-amino-1,3-naphthalenedisulfonic acid), 2,6-naphthalenedisulfonic acid (2,6-naphthalenedisulfonic acid), 1,3,6-naphthalenetrisulfonic acid (1,3,6-naphthalenetrisulfonic acid), 4-hydroxy-2,7-naphthalenedisulfonic acid (4-hydroxy-2,7-naphthalenedisulfonic acid), 3-hydroxy-4-nitroso-2,7- Naphthalene disulfonic acid (3-hydroxy-4-nitroso-2,7-naphthalenedisulfonic acid) and 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid) acid), characterized in that it is selected from the group consisting of
delete delete According to claim 1,
Method for producing anhydrosugar alcohol, characterized in that dehydration at a temperature of 150 ~ 200 ℃.
According to claim 1,
Method for producing anhydrosugar alcohol further comprising the step of distilling the anhydrosugar alcohol produced in the dehydration reaction.
According to claim 1,
The anhydrosugar alcohol is child carbide, and the sugar alcohol is a method for producing anhydrosugar alcohol, characterized in that sorbitol.
According to claim 1,
A method of producing anhydrosugar alcohol, characterized in that it is carried out in a continuous stirred tank reactor (CSTR), a plug flow reactor (PFR) or a batch reactor (Batch Reactor, BR).