Method for preparing lactic acid by catalyzing pyruvic aldehyde

A technology of aceglyoxal and lactic acid, applied in the direction of oxidative preparation of carboxylic acid, chemical instruments and methods, molecular sieve catalyst, etc., can solve the problems of large-scale production and application of lactic acid, air pollution, large solid waste, etc. Large-scale industrial production application, high conversion rate of aceglyoxal, and effect of improving reaction efficiency

Active Publication Date: 2020-06-09
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The process has a long reaction route, high production cost and produces a large amount of solid waste, which makes it impossible to realize large-scale production and application of lactic acid at present.
The commonly used chemical synthesis methods are the lactonitrile method and the propionic acid method. The lactonitrile method uses acetaldehyde and highly toxic hydrocyanic acid as the reaction raw materials, and concentrated sulfuric acid as the catalyst. Therefore, the production process is seriously polluted and has potential safety hazards.
The propionic acid method uses toxic chlorine gas as a raw material, which not only requires high operational safety and airtightness, but also easily pollutes the atmospheric environment

Method used

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  • Method for preparing lactic acid by catalyzing pyruvic aldehyde

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Embodiment approach

[0049] According to the first embodiment, preferably the tin-titanium-silicon molecular sieve is at 460 cm in the FT-IR spectrum -1 、975cm -1 、800cm -1 and 1080cm -1 There is absorption nearby. Preferably, the tin-titanium-silicon molecular sieve has absorption at 200-300 nm in the UV-Vis spectrum, preferably at 200-260 nm.

[0050] According to the first embodiment, preferably the molar ratio of the tin element to the silicon element in the tin-titanium-silicon molecular sieve is 0.05-10:100, more preferably 0.1-5:100, particularly preferably 0.2-2:100. Preferably, the molar ratio of titanium element to silicon element in the tin-titanium-silicon molecular sieve is 0.05-10:100, more preferably 0.1-5:100, particularly preferably 0.5-4:100. Such proportions of tin, titanium and silicon can further optimize the catalytic activity of the tin-titanium-silicon molecular sieve of the present invention.

[0051] According to the first embodiment, it is preferred that the tin-tit...

preparation Embodiment 1

[0095] In this preparation example, a Sn-Ti-MFI-1 molecular sieve is prepared according to the method of Example 1 of the Chinese patent CN 105217645A specification, and the specific preparation method is as follows:

[0096] (1) At 25°C, stirring and contacting tetrapropylammonium hydroxide aqueous solution (concentration: 15% by weight) with tetrabutyl titanate and tin tetrachloride pentahydrate for 30 minutes to obtain a mixture;

[0097] (2) At 60°C, add silicon molecular sieve S-1 to the above mixture and stir for 0.5h to obtain the mixture (during this contact process, add water or not add water as required, if the feeding in step (1) can meet the requirement of water Feeding requirements, there is no need to add water, if it is not met, you can add water when the mixture containing tetrapropylammonium hydroxide, tetrabutyl titanate and tin chloride is stirred and contacted with silicon molecular sieve, or distill off water, and the rest The preparation examples are simi...

preparation Embodiment 2

[0101] This preparation example prepares the Sn-Ti-MFI-2 molecular sieve according to the method of the Chinese patent CN105217645A specification example 2, and the specific preparation method is as follows:

[0102] (1) At 25°C, stirring and contacting tetrapropylammonium hydroxide aqueous solution (concentration: 20% by weight) with tetrabutyl titanate and tin tetrachloride pentahydrate for 30 minutes to obtain a mixture;

[0103] (2) At 25°C, add silicon molecular sieve S-1 to the above mixture and stir for 0.5h to obtain the mixture; wherein, ensure that the molar ratio of each substance is: silicon source (silicon molecular sieve): alkali source template (four Propyl ammonium hydroxide): titanium source (tetrabutyl titanate): tin source (tin tetrachloride): water=100:15:2:0.1:200, wherein the silicon source is SiO 2 In terms of titanium source as TiO 2 Tin source is calculated as tin element;

[0104] (3) Transfer the above mixture into a sealed stainless steel reaction...

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Abstract

The invention relates to a method for preparing lactic acid by catalyzing pyruvic aldehyde. The method comprises the following steps: contacting pyruvic aldehyde, water and a catalyst in a reactor, and reacting to obtain a product containing lactic acid, wherein the molar ratio of the pyruvic aldehyde to the water is 1:(40-350), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 hours, the catalyst contains a tin-titanium-silicon molecular sieve, and the weight ratio of the pyruvic aldehyde to the tin-titanium-silicon molecular sieve based on dry basis weight is 1:(1-6). The method provided by the invention has high pyruvic aldehyde conversion rate and high lactic acid yield.

Description

technical field [0001] The invention relates to a method for preparing lactic acid by catalyzing methylglyoxal. Background technique [0002] Lactic acid (scientific name: 2-hydroxypropionic acid) is a compound that plays a role in a variety of biochemical processes with the formula C 3 h 6 o 3 . It is a carboxylic acid containing a hydroxyl group and is therefore an alpha-hydroxy acid. In aqueous solution, its carboxyl group releases a proton to produce lactate ion. Lactate dehydrogenase converts pyruvate to L-lactate during fermentation. Lactate is continuously produced during normal metabolism and exercise, but its concentration generally does not rise. Lactic acid is a colorless liquid, and the industrial product is a colorless to pale yellow liquid. Odorless, hygroscopic, relative density 1.200, melting point 18°C, boiling point 122°C, flash point greater than 110°C, miscible with ethanol, ether, water, glycerin, insoluble in chloroform, carbon disulfide and petr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/16C07C59/08B01J29/40
CPCC07C51/16B01J29/405C07C59/08Y02P20/584
Inventor 朱斌刘聿嘉夏长久林民彭欣欣罗一斌舒兴田
Owner CHINA PETROLEUM & CHEM CORP
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