Method for preparing lactate without alkali or solvent

Abstract

The invention provides a method for preparing lactate without alkali or solvent, and relates to the technical field of lactate preparation. The preparation method comprises the following steps of: reacting raw materials under the action of a metal catalyst and an alcohol auxiliary agent in an aerobic atmosphere at a temperature of 80-180DEG C to obtain lactate, wherein the raw materials comprise saccharide raw materials and / or alcohol raw materials, the metal catalyst comprises a carrier and metals loaded on the carrier, the carrier comprises activated carbon and metal oxide, and the metals comprise two or three of Pt, Pd, Rh, Ir, Au, Cu, Ni, Co and Fe, the alcohol auxiliary agent is an alcohol compound with a carbon atom number of 1-4. According to the method for preparing the lactate, alkali and solvent are not added, corrosion to equipment and separation energy consumption can be remarkably reduced, one-step preparation of lactate is achieved, the technological process is greatly simplified, high lactate yield can be guaranteed, and the conversion rate of raw materials can reach 100%.

Description

technical field

[0001] The invention relates to the technical field of lactate preparation, in particular to a method for preparing lactate without alkali and solvent. Background technique

[0002] Lactate is an important compound with a wide range of applications. Low-molecular-weight lactate is a non-toxic, biodegradable green solvent that can be used to prepare compounds such as acrylate and lactide and materials such as nanofiltration membranes. In addition, it can also be used for Produce pesticides, medicines, skin care products, food additives, spices, and can be used as functional coatings and cleaning agents in metal processing. In addition, they are also used in soil pollution control.

[0003] The preparation of lactic acid esters in industry is usually first synthesized lactic acid, and then esterified lactic acid and alcohol under the action of a catalyst (mainly concentrated sulfuric acid). longer. Moreover, in the process of synthesizing the intermediate pro...

Examples

preparation example Construction

[0031] The present invention has no special requirements on the preparation method of the metal catalyst, and it can be prepared by a precipitation method or an impregnation method well known to those skilled in the art.

[0032] In a specific embodiment of the present invention, when the carrier of the metal catalyst is a metal oxide, the preparation of the metal catalyst is preferably a precipitation method, and the preparation process preferably includes the following steps:

[0033] (1) adding the mixed salt solution of each of the metals and the lye synchronously dropwise into the aqueous dispersion of the carrier to carry out the precipitation reaction, and the obtained reaction feed liquid is subjected to aging and solid-liquid separation in sequence to obtain a solid;

[0034] (2) Calcining the solid matter in step (1) in a reducing atmosphere to obtain the metal catalyst.

[0035]In the present invention, the preparation method of the mixed salt solution of each of th...

Embodiment 1

[0050] Preparation of Lactate from Glucose

[0051] With Pt(2)Au(2) / TiO 2 As a metal catalyst, methanol is used as an alcohol additive (Note: Pt(2)Au(2) / TiO 2 Catalyst expressed as TiO 2 For the carrier, load Pt and Au bimetallic, the loading of Pt is 2wt%, the loading of Au is 2wt%, and the metal catalysts in each embodiment are all expressed in this way):

[0052] (1) Precipitation method is adopted to prepare catalyst:

[0053] First chloroplatinic acid and chloroauric acid are dissolved in water in the same container to obtain a mixed salt solution, and the concentrations of chloroplatinic acid and chloroauric acid in the mixed salt solution are 0.1mol / L and 0.1mol / L respectively; and lye (NaOH solution, the concentration is 1mol / L) to another stirred TiO 2 In the water dispersion (100g / L), the precipitation reaction is carried out dropwise, the drop rate of the lye is 0.02mL / s, the drop rate of the mixed salt solution is 2 seconds / drop at the beginning, 1 second / drop ...

Embodiment 2

[0058] Preparation of Lactate from Glucose

[0059] Using the metal catalyst shown in Table 1, using methanol as an alcohol additive, and using glucose as a raw material to prepare lactate, the metal catalyst in Table 1 is prepared with reference to the process of Example 1, and the metal salt solution can be replaced accordingly (The metal salt of Cu is copper nitrate). Lactate was prepared as follows:

[0060] Put 0.1g of metal catalyst, 3.0g of glucose into the reaction kettle, add methanol additive to a total volume of 5mL; fill the reaction kettle with 1MPa O 2 , set the reaction temperature (as shown in table 1), the reaction time 8h, the catalytic effects of different metal catalysts on the preparation of lactate from glucose are shown in table 1:

[0061] Table 1 adopts the effect of different metal catalysts to prepare lactate with glucose

[0062]

technical field

[0001] The invention relates to the technical field of lactate preparation, in particular to a method for preparing lactate without alkali and solvent. Background technique

[0002] Lactate is an important compound with a wide range of applications. Low-molecular-weight lactate is a non-toxic, biodegradable green solvent that can be used to prepare compounds such as acrylate and lactide and materials such as nanofiltration membranes. In addition, it can also be used for Produce pesticides, medicines, skin care products, food additives, spices, and can be used as functional coatings and cleaning agents in metal processing. In addition, they are also used in soil pollution control.

[0003] The preparation of lactic acid esters in industry is usually first synthesized lactic acid, and then esterified lactic acid and alcohol under the action of a catalyst (mainly concentrated sulfuric acid). longer. Moreover, in the process of synthesizing the intermediate pro...

Examples

preparation example Construction

[0031] The present invention has no special requirements on the preparation method of the metal catalyst, and it can be prepared by a precipitation method or an impregnation method well known to those skilled in the art.

[0032] In a specific embodiment of the present invention, when the carrier of the metal catalyst is a metal oxide, the preparation of the metal catalyst is preferably a precipitation method, and the preparation process preferably includes the following steps:

[0033] (1) adding the mixed salt solution of each of the metals and the lye synchronously dropwise into the aqueous dispersion of the carrier to carry out the precipitation reaction, and the obtained reaction feed liquid is subjected to aging and solid-liquid separation in sequence to obtain a solid;

[0034] (2) Calcining the solid matter in step (1) in a reducing atmosphere to obtain the metal catalyst.

[0035]In the present invention, the preparation method of the mixed salt solution of each of th...

Embodiment 1

[0050] Preparation of Lactate from Glucose

[0051] With Pt(2)Au(2) / TiO 2 As a metal catalyst, methanol is used as an alcohol additive (Note: Pt(2)Au(2) / TiO 2 Catalyst expressed as TiO 2 For the carrier, load Pt and Au bimetallic, the loading of Pt is 2wt%, the loading of Au is 2wt%, and the metal catalysts in each embodiment are all expressed in this way):

[0052] (1) Precipitation method is adopted to prepare catalyst:

[0053] First chloroplatinic acid and chloroauric acid are dissolved in water in the same container to obtain a mixed salt solution, and the concentrations of chloroplatinic acid and chloroauric acid in the mixed salt solution are 0.1mol / L and 0.1mol / L respectively; and lye (NaOH solution, the concentration is 1mol / L) to another stirred TiO 2 In the water dispersion (100g / L), the precipitation reaction is carried out dropwise, the drop rate of the lye is 0.02mL / s, the drop rate of the mixed salt solution is 2 seconds / drop at the beginning, 1 second / drop ...

Embodiment 2

[0058] Preparation of Lactate from Glucose

[0059] Using the metal catalyst shown in Table 1, using methanol as an alcohol additive, and using glucose as a raw material to prepare lactate, the metal catalyst in Table 1 is prepared with reference to the process of Example 1, and the metal salt solution can be replaced accordingly (The metal salt of Cu is copper nitrate). Lactate was prepared as follows:

[0060] Put 0.1g of metal catalyst, 3.0g of glucose into the reaction kettle, add methanol additive to a total volume of 5mL; fill the reaction kettle with 1MPa O 2 , set the reaction temperature (as shown in table 1), the reaction time 8h, the catalytic effects of different metal catalysts on the preparation of lactate from glucose are shown in table 1:

[0061] Table 1 adopts the effect of different metal catalysts to prepare lactate with glucose

[0062]

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