CN1167106A

CN1167106A - Method for synthesizing pyruvate by lactate catalyzing

Info

Publication number: CN1167106A
Application number: CN 97106373
Authority: CN
Inventors: 项一非; 郭柏麟; 沈伟; 徐华龙; 周亚明
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 1997-04-10
Filing date: 1997-04-10
Publication date: 1997-12-10
Anticipated expiration: 2017-04-10
Also published as: CN1060759C

Abstract

The catalytic oxidation synthesis of pyruvate is characterized by that in the presence of modified silver or copper catalyst said invention uses gas phase atmospheric oxidation of lactate to prepare pyruvate. Its dressing agent is a halide, and one or several kinds of P, Zr, Zn and K also can be added. Its reaction temp. is 300-600 deg.C, and according to different technological processes, the crude pyruvate products with low concentration and high concentration can be respectively prepared, and after rectification the invented refined product can be obtained.

Description

A kind of method of synthesizing pyruvate by lactate catalyzing

The present invention relates to produce a kind of method of pyruvate by lactate.Pyruvate is a pyruvic acid aliphatic alkyl ester, as Pyruvic Acid Methyl ester, Pyruvic Acid Ethyl ester, Propyl pyruvate, the positive butyl ester of pyruvic acid, pyruvic acid isobutyl ester etc., the present invention is in the presence of modified silver or copper catalyst, makes the lactate gaseous oxidation and generates pyruvate.

Pyruvate is a kind of important medicine intermediate, can synthesize multiple medicine, as anti-cardiovascular agent, also can make multiple biochemical preparation, as pyruvate salt.Known technology has the multiple method for preparing pyruvate, for example ethyl lactate, sherwood oil, SODIUM PHOSPHATE, MONOBASIC, potassium permanganate reacted together, and with potassium permanganate oxygenant oxidation lactate, then pyruvate is steamed.What also have produces pyruvate with hydrogen peroxide as oxygenant oxidation lactate.These class methods all add oxygenant and in liquid phase lactate are oxidized to pyruvate in lactate, and then separate, and purify.German Patent 2,809,421 have narrated the method that is prepared pyruvate by the lactate atmospheric oxidation, have used crystallization silver to be catalyzer in this method.Japanese Patent 86 97 has used the silver catalyst through the P modification in 247, with silver at NH ₄H ₂PO ₄Flood in the solution, P amount＜300 ppm are carried in roasting then.Single is that the yield of catalyzer pyruvate is not ideal enough with crystallization silver, and makes catalyzer with the silver of dipping P, and the transformation efficiency of lactate descends to some extent, and has adiabatic reactor catalyst reactor firing up difficulty, floods P with reacting problem such as slowly loss.

The purpose of this invention is to provide a kind of method, and seek to be used for the modified silver or the copper catalyst of this synthetic method, thereby a kind of method of synthesizing pyruvate by lactate catalyzing of high yield is provided by synthesizing pyruvate by lactate catalyzing.

The method of synthesizing pyruvate by lactate catalyzing of the present invention, be that lactate, water vapor and oxygen-containing gas are mixed together the adding oxidation reactor, this oxidation reactor is a fixed bed adiabatic reactor, catalyzer is that granularity is the particle of 0.1～4mm, fixed bed is inserted in layering, and reactant is continuously by being loaded with the fixed bed of catalyzer.The mol ratio of reactant oxygen and lactate is 0.4～5, and the mol ratio of water and lactate is 0.1～1.5, and the liquid hourly space velocity degree of lactate is that the amount (LHSV) by lactate liquid is 1～120hr in the per volume of catalyst unit time ^-1, obtaining the required reactant throughput of oxidizing reaction good result can change in very wide scope, and by aforementioned data, the air speed of lactate on catalyzer is 2 * 10 ²～2.4 * 10 ⁴Hr ^-1, reactant is between 0.15～20 second in duration of contact on the catalyzer.Oxidizing reaction temperature is 300～600 ℃.

The present invention is in order to improve the concentration of product pyruvate, available tail gas or rare gas element circulation, make the pyruvate crude product of high density, its weight concentration can reach 35～80%, if can make the pyruvate crude product of lower concentration without circulation gas, its weight concentration is 10～50%, and the indication rare gas element is not for participating in the gas of reaction, as nitrogen etc.

The reactant lactate can also can the air bubbling be taken lactate out of by heating vaporization and air mixed, and the vaporization of raw water used water also can directly be used water vapor.

Catalyzer of the present invention is modified silver or copper catalyst, and the modifier of silver catalyst is a halogenide, also can add among Zr, Zn, the K one or more, and the modifier of copper catalyst is halogenide and P, and the molar content that modifier accounts for catalyzer is:

Modifier content in the silver catalyst:

Halogenide: 0.1～50ppm

Zr： 0～500ppm

Zn： 0～500ppm

K： 0～500ppm

Modifier content in the copper catalyst:

Halogenide: 0.1～50ppm

P： 0.1～10％

The halogenide of silver catalyst is modified and is adopted the steam infiltration method, is about to gas halogen compound steam and brings catalytic bed into, makes it to infiltrate catalyst crystal lattice.Pickling process is adopted in the adding of Zr, Zn, K, and be about to catalyzer and be immersed in the soluble salt solution of Zr, Zn, K, about 12 hours after-filtration, 80 ℃ of oven dry are then 500～600 ℃ of roastings.Zr, Zn, K modifier add one or more and all can play promoting catalysis, and its addition can be regulated in the scope of above-mentioned broad, and generalized case is added a kind of modifier again and can be played promoting catalysis except that halogenide.

The halogenide of copper catalyst is modified and is adopted the steam infiltration method, and the copper-phosphorus alloy method is adopted in the adding of P, is about to that metallic copper and elemental phosphorous mixing are melt and dissolved to become alloy, mechanical-moulded getting final product after the cooling.

Wherein halogenide can be Organohalogen compounds such as monobromethane, monobromethane, methyl chloride, monochloroethane.

Catalyzer is filled in the fixed bed adiabatic reactor by the granularity layering, and reactant is passed through catalyst bed continuously.Catalyzer is the particle of diameter 0.1～4mm, and the filling of catalyzer highly is 5～200mm.

The used lactate of the inventive method is suitable for all lactic acid ester reactants, as methyl lactate, ethyl lactate etc., for general industry level product gets final product.Air is not for containing the cleaned air of dust, volatile sulfur, chlorine, iron cpd, and water is the soft water or the water vapor of not sulfur-bearing, chlorine, iron ion.

The present invention prepares pyruvate with the successive single stage method with the lactate catalyzing oxidation, owing to adopted efficient modified silver or copper catalyst, has obtained the pyruvate of high yield.The reactant oxygen-containing gas is that general air gets final product, and the mixture of air and lactate almost can transform lactate by a kind of modified silver or copper catalyst quantitatively in gas phase oxidation.Do not form coke button formula tar in the reactor, the pyruvate maximum output that obtains can reach more than 80%, and by product is mainly the hydrolyzate of ester, and reaction product is separable purification by rectifying, obtains concentration greater than 99% elaboration.

Embodiment:

1. the crystallization silver of this example employing infiltration 1ppm bromide is catalyzer.

5 gram catalyzer are packed in the stainless steel reactor of a diameter 16mm, loading height 18mm, with air the ethyl lactate bubbling in the vaporizer is taken out of, ethyl lactate, air and enter catalytic bed after the water vapor of adding mixes react in mixing tank, the inlet amount of ethyl lactate is 30g/hr., and the air feed amount is 0.035M ³/ hr., the inlet amount of water is 20g/hr., the liquid hourly space velocity LHSV of ethyl lactate is 104,520 ℃ of control reaction temperature obtain Pyruvic Acid Ethyl ester concentration and are 42% solution, after the rectifying purity greater than 99% product, the transformation efficiency 100% of ethyl lactate, the selectivity 74.9% of Pyruvic Acid Ethyl ester.

2. this example adopts and infiltrates the 5ppm bromide, and floods the Zr of 20ppm respectively, Zn, and the crystallization silver of K is catalyzer.

Add 5 gram catalyzer in the same reaction tubes, be mixed into reactor with air, nitrogen after ethyl lactate, water are vaporized in vaporizer, the inlet amount of ethyl lactate is 30g/hr., and the liquid hourly space velocity LHSV of ethyl lactate is 104, and the air feed amount is 0.04M ³/ hr., the nitrogen feed amount is 0.18M ³/ hr., the inlet amount of water is 5g/hr., 500 ℃ of control reaction temperature obtain Pyruvic Acid Ethyl ester concentration and are 67% ethylpyruvate solution, after the rectifying purity greater than 99% product, the transformation efficiency 99.5% of ethyl lactate, the selectivity 83.1% of Pyruvic Acid Ethyl ester.

3. this example adopts the catalyzer and the reactor of example 1, and methyl lactate gasification back is mixed into reactor with air, recycled offgas, and circulation gas adopts reaction end gas, part exhaust emissions in the reaction process.The inlet amount of ethyl lactate is 20g/hr., and the liquid hourly space velocity LHSV of methyl lactate is 70, and the air feed amount is 0.02M ³/ hr., the tail gas internal circulating load is 0.1M ³/ hr., tail gas band saturated vapor 3.2g/hr, 480 ℃ of temperature of reaction obtain Pyruvic Acid Methyl ester concentration and are 73% solution, after the rectifying purity greater than 99% product, the transformation efficiency 100% of methyl lactate, the selectivity 79.1% of Pyruvic Acid Methyl ester.

4 examples adopt and contain the 8ppm muriate, and the copper of 2%P is catalyzer.

8 gram catalyzer are packed in the stainless steel reactor of a diameter 16mm, loading height 80mm, with air the ethyl lactate bubbling in the vaporizer is taken out of, ethyl lactate, air and enter catalytic bed after the water vapor of adding mixes react in mixing tank, the inlet amount of ethyl lactate is 30g/hr, the liquid hourly space velocity LHSV of ethyl lactate is 23.4, and the air feed amount is 0.038M ³/ hr, the inlet amount of water is 10g/hr., 350 ℃ of control reaction temperature obtain Pyruvic Acid Ethyl ester concentration and are 50% solution, after the rectifying purity greater than 99% product, the transformation efficiency 100% of ethyl lactate, the selectivity 68.9% of Pyruvic Acid Ethyl ester.

Claims

The method of 1 one kinds of synthesizing pyruvate by lactate catalyzing is characterized in that lactate, water and oxygen-containing gas reactant are mixed into the modified silver or the fixed bed adiabatic reactor of copper catalyst are housed, and reaction conditions is:

(1) mol ratio of oxygen and lactate is 0.4 to 5, and the mol ratio of water and lactate is 0.1～1.5;

(2) liquid hourly space velocity of lactate (LHSV) is 1～120hr ^-1

(3) oxidizing reaction temperature is 300～600 ℃.
2. the method for synthesizing pyruvate by lactate catalyzing according to claim 1 is characterized in that available tail gas or rare gas element circulation in the reaction process.
3. the method for synthesizing pyruvate by lactate catalyzing according to claim 1, the vaporization that it is characterized in that lactate can be to be heated to above vaporization of boiling point or the evaporation of gas bubbling.
4. the silver of a synthesizing pyruvate by lactate catalyzing or copper catalyst modifying method, the modifier that it is characterized in that silver catalyst is a halogenide, also can add among P, Zr, Zn, the K one or more, the molar content that modifier accounts for silver catalyst is:

Halogenide: 0.1～50ppm

Zr： 0～500ppm

Zn： 0～500ppm

K： 0～500ppm

The modifier of copper catalyst is halogenide and P, and the molar content that modifier accounts for copper catalyst is:

Halogenide: 0.1～50ppm

P： 0.1～10％
5. the modifying method of the silver of synthesizing pyruvate by lactate catalyzing according to claim 4 or copper catalyst, halogenide adopts the steam infiltration method when it is characterized in that modifying silver catalyst, and pickling process is adopted in the adding of Zr, Zn, K.
6. the modifying method of the silver of synthesizing pyruvate by lactate catalyzing according to claim 4 or copper catalyst, halogenide adopts the steam infiltration method when it is characterized in that modifying copper catalyst, and the copper-phosphorus alloy method is adopted in the adding of P.
7. the modifying method of the silver of synthesizing pyruvate by lactate catalyzing according to claim 4 or copper catalyst is characterized in that catalyst grain size 0.1～4mm, catalyst filling height 5～200mm.