A method for preparing 5-hydroxymethylfurfural by hydrolysis

Abstract

The present invention discloses a method for preparing 5-hydroxymethylfurfural by hydrolysis, which belongs to the field of chemical product preparation. The method comprises the following steps: taking corn cobs, a catalyst, and a co-catalyst, stirring and mixing them thoroughly, placing them in a reactor for reaction; transferring and cleaning the reacted materials with deionized water, and obtaining the 5-hydroxymethylfurfural after suction filtration. Compared with the prior art, the present invention uses corn cobs as raw materials, utilizes the synergistic effect of co-catalysts and inorganic acids, degrades corn cobs to prepare 5-hydroxymethylfurfural, and overcomes the shortcomings of the prior art such as high raw material costs and low yields. The method has the advantages of high yield and low co-catalyst usage.

Description

Technical Field

[0001] The present invention relates to the field of chemical product preparation, and in particular to a method for preparing 5-hydroxymethylfurfural by a hydrolysis method. Background Art

[0002] 5-Hydroxymethylfurfural is an important fine chemical product with a wide range of applications. Currently, 5-Hydroxymethylfurfural is produced industrially by dehydrating fructose or glucose, but this suffers from low yields (around 50%) and high raw material costs, resulting in high production costs. Corncobs are an abundant and inexpensive agricultural byproduct, and 5-Hydroxymethylfurfural can also be produced using corncobs and inorganic acids as catalysts, but this also suffers from low yields (20%-36%). Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention proposes a method for preparing 5-hydroxymethylfurfural by a hydrolysis method.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing 5-hydroxymethylfurfural by hydrolysis comprises the following steps:

[0006] Take corn cobs, catalyst and co-catalyst, stir and mix them thoroughly, and put them into a reactor for reaction;

[0007] The reacted material is transferred and washed with deionized water, and the 5-hydroxymethylfurfural is obtained after suction filtration.

[0008] Optionally, the reactor material temperature is between 180°C and 250°C.

[0009] A raw material formula for preparing 5-hydroxymethylfurfural comprises the following components:

[0010] corn cobs; and

[0011] Catalysts and co-catalysts.

[0012] Optionally, the catalyst is sulfuric acid.

[0013] Optionally, the co-catalyst is a mixture of one or more of 2,2-bis(4-hydroxyphenyl)propane, ammonium thiocyanate, and sodium thiocyanate.

[0014] Optionally, the solid-liquid mass ratio of the corn cob to the dilute sulfuric acid and promoter aqueous solution is 1:1.2 to 1:1.5.

[0015] Optionally, the amount of sulfuric acid added is 2.8%-3% of the mass of the corncob.

[0016] Optionally, the added amount of the co-catalyst accounts for 0.05%-0.2% of the mass of the corncob.

[0017] Beneficial effects of the present invention:

[0018] The beneficial effects of the present invention are: high yield, based on the monomer of cellulose in corn cobs, the yield of 5-hydroxymethylfurfural reaches 92%-99%, low raw material cost, and corn cobs are a by-product of agricultural production, which is large in quantity and cheap. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1: According to the steps of the present invention, corn cobs with a water content of 20% were mixed with dilute sulfuric acid and a promoter aqueous solution at a solid-liquid mass ratio of 1:1.2. The amount of sulfuric acid added was controlled to account for 3% of the mass of the corn cobs. No promoter was added. The mixture was stirred thoroughly until the corn cobs were evenly wetted and the corn cobs had a particle size of less than 0.22 mm. The evenly wetted corn cobs were placed in a polytetrafluoroethylene reactor and compacted to a bulk density of about 1.2 g / cm 3 After sealing, fix it with a metal shell and place it in a constant temperature reactor. The temperature of the constant temperature reactor is controlled at 225°C. The reaction is carried out at this temperature for 2 hours. The reactor is taken out and cooled to room temperature with tap water. The reactor is opened and all the materials are transferred and washed with 100 mL of deionized water and transferred to a 300 mL beaker. The mixture is fully stirred for 5 minutes. The material suspension is filtered to obtain a light yellow transparent filtrate. The product concentration in the filtrate is analyzed by high performance liquid chromatography, and the calculated yield is 82.05%.

[0021] Example 2: According to the steps of the present invention, corn cobs with a water content of 20% are mixed with dilute sulfuric acid and a promoter aqueous solution in a solid-liquid mass ratio of 1:1.2, the amount of sulfuric acid added is controlled to account for 3% of the mass of the corn cobs, and the amount of the promoter ammonium thiocyanate added is controlled to account for 0.2% of the mass of the corn cobs. The mixture is stirred thoroughly until the corn cobs are evenly wetted, and the particle size of the corn cobs is less than 0.22 mm. The evenly wetted corn cobs are placed in a polytetrafluoroethylene reactor and compacted to a bulk density of about 1.2 g / cm 3After sealing, fix it with a metal shell and place it in a constant temperature reactor. The temperature of the constant temperature reactor is controlled at 225°C. The reaction is carried out at this temperature for 2 hours. The reactor is taken out and cooled to room temperature with tap water. The reactor is opened and all the materials are transferred and washed with 100 mL of deionized water and transferred to a 300 mL beaker. The mixture is fully stirred for 5 minutes. The material suspension is filtered to obtain a light yellow transparent filtrate. The product concentration in the filtrate is analyzed by high performance liquid chromatography. The calculated yield is 99.01%, which is 20.67% higher than that in Comparative Example 1.

[0022] Example 3: According to the steps of the present invention, corn cobs with a water content of 20% are mixed with dilute sulfuric acid and a promoter aqueous solution in a solid-liquid mass ratio of 1:1.5, the amount of sulfuric acid added is controlled to account for 2.8% of the mass of the corn cobs, and the amount of the promoter ammonium thiocyanate added is controlled to account for 0.05% of the mass of the corn cobs. The mixture is stirred thoroughly until the corn cobs are evenly wetted, and the particle size of the corn cobs is less than 0.22 mm. The evenly wetted corn cobs are placed in a polytetrafluoroethylene reactor and compacted to a bulk density of about 1.2 g / cm 3 After sealing, fix it with a metal shell and place it in a constant temperature reactor. The temperature of the constant temperature reactor is controlled at 225°C. The reaction is carried out at this temperature for 2 hours. The reactor is taken out and cooled to room temperature with tap water. The reactor is opened and all the materials are transferred and washed with 100 mL of deionized water and transferred to a 300 mL beaker. The mixture is fully stirred for 5 minutes. The material suspension is filtered to obtain a light yellow transparent filtrate. The product concentration in the filtrate is analyzed by high performance liquid chromatography, and the calculated yield is 92.08%.

[0023] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0024] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A method for preparing 5-hydroxymethylfurfural by hydrolysis, characterized in that: The following steps are involved: The corn cob, the catalyst and the co-catalyst are mixed and stirred thoroughly, and then placed in a reactor for reaction, wherein the catalyst is sulfuric acid and the co-catalyst is ammonium thiocyanate; The reacted material is transferred and washed with deionized water, and the 5-hydroxymethylfurfural is obtained after suction filtration.

2. The method for preparing 5-hydroxymethylfurfural by hydrolysis according to claim 1, wherein The reactor material temperature is between 180℃ and 250℃.