WO2011088616A1 - Preparation method for acetonitrile and/or ethanol by dehydrogenating methanol and ammonia - Google Patents

Abstract

A preparation method for acetonitrile and/or ethanol by mixing and dehydrogenating methanol and ammonia as reactants in presence of the solid catalyst wherein copper is the main component. The present method includes providing methanol in presence of or in absence of water and ammonia into the reactor filled with catalyst wherein copper is the main component, dehydrogenating to produce acetonitrile, ethanol, water and hydrogen, separating the reaction mixture and then obtaining acetonitrile or ethanol as the product.

Description

 Method for dehydrogenating methanol and ammonia to acetonitrile and/or ethanol

 The present invention relates to a process for the dehydrogenation of acetonitrile and/or ethanol by mixing methanol with ammonia in the presence of a copper solid catalyst.

 Technical background

 Ammoxidation of propylene to acrylonitrile by-product 2 to 3% of acetonitrile. Patent 03112026 reports a process for the ammoxidation of ethanol to acetonitrile in which one of the reactants is oxygen. Patent 200910000934.4 reports a method for the dehydrogenation of ethanol and ammonia to acetonitrile. The method uses only ethanol and ammonia to avoid the use of oxygen. At present, there is no method for direct dehydrogenation of methanol and ammonia to acetonitrile at home and abroad. In this method, C1 methanol forms C2 acetonitrile, and carbon-carbon bond is formed during the reaction, which is a completely new method, and methanol is used instead of ethanol. The cost is greatly reduced. Summary of the invention

 SUMMARY OF THE INVENTION The object of the present invention is a process for the preparation of acetonitrile and/or ethanol by mixed dehydrogenation in the presence of a copper solid catalyst by means of a reaction of methanol and ammonia, which also produces by-product hydrogen and water.

 The method of the present invention consists in a method for preparing acetonitrile and/or ethanol by reacting methanol with ammonia in the presence of a solid catalyst comprising copper or copper oxide as a main component, comprising the steps of: methanol and ammonia entering a packed copper or A reactor in which a copper oxide is a main component, a dehydrogenation reaction is carried out to produce acetonitrile and/or ethanol, water and hydrogen, and the reacted mixture is separated to obtain a product of acetonitrile or ethanol, wherein a molar ratio of methanol to ammonia It is 0.1~10: 1.

The advantage of this process is that the raw materials are easily available, methanol is a bulk chemical, coal or natural gas or oil field tail gas produces syngas, and then syngas produces methanol; the reaction is a micro-endothermic reaction, the reaction heat absorption is about ethanol-ammonia mixed dehydrogenation One-third of acetonitrile is used to save energy; the process is stable, the by-products of the reaction are water and hydrogen, and the environment is friendly. In this reaction, oxygen is not an essential raw material, but oxygen which does not exceed 1.5 times the mole of methanol may be added to promote oxidation of methanol. DRAWINGS

 The features of the present invention will become more apparent from the written description and appended claims.

 Figure 1 illustrates the main flow of methanol to ammonia reaction.

 After the methanol is mixed with ammonia, it is heated and vaporized and then enters the reactor. The reactor is heated by hot oil or steam. The reacted mixture contains acetonitrile and/or ethanol, unreacted methanol, ammonia and by-product water, hydrogen, and the middle. The product dimethyl ether, methyl formate, methylamine, etc., is condensed and then enters the gas-liquid separator. The hydrogen-containing gas phase enters the gas separation process, and the liquid phase containing acetonitrile or ethanol enters the liquid separation process to obtain acetonitrile, unreacted ammonia and Methanol and intermediates are either returned to the reactor or used for other purposes.

 Figure 2 is a confirmation of the acetonitrile and ethanol on the GC-MS spectrum after the reaction.

detailed description

 After the methanol is mixed with ammonia, it is heated and vaporized and then enters the reactor. The reactor is heated by hot oil or steam. The reacted mixture contains acetonitrile and/or ethanol, unreacted methanol, ammonia and by-product water, hydrogen, and the middle. The product dimethyl ether, methyl formate, methylamine, etc., is condensed and then enters the gas-liquid separator, the gas phase enters the gas separation process, and the liquid phase enters the liquid separation process to produce acetonitrile, unreacted ammonia and methanol, and intermediates or back. Reactor, or for other uses.

 Typical gas separation processes are both compression and absorption, but are not limited to these two. In the absorption process, water is absorbed in the absorption tower with water or other solvent, ammonia enters the liquid phase, and hydrogen gas goes to the next stage. In the compression process, the gas phase material is pressurized to liquefy the ammonia.

 Typical liquid separation processes include extractive distillation and vacuum distillation. In the extractive distillation method, the azeotrope of acetonitrile and water is destroyed by an extractant. In the vacuum distillation method, first, vacuum distillation, followed by pressure distillation, under reduced pressure, the water content of the acetonitrile and water azeotrope is low, under pressure, the azeotrope of acetonitrile and water High water content, plus vacuum distillation is the use of this difference to achieve the separation of acetonitrile and water.

 In the method, the molar ratio of methanol to ammonia is 0.1 to 10:1, preferably 0.5 to 4:1.

Hereinafter, the content is expressed by mass percentage unless otherwise stated. Methanol may or may not contain water and the water content is not limited.

 The other raw material is liquid ammonia or ammonia, which can contain water.

 The catalyst used is a solid catalyst in which the main component is an oxide of copper or copper, and the content of copper is 5 to 65%, preferably 15 to 45%. In addition to copper, it contains other components selected from the group consisting of ruthenium, gold, zirconium, palladium, aluminum, zinc, titanium, ruthenium, magnesium or oxides thereof. Their content can be 0~15% bismuth, 0~20% gold, 0~45% zirconium, 0~10% palladium, 0~40% aluminum, 0-50% zinc, 0~30% Titanium, 0~10% bismuth or 0~60% magnesium.

 The catalyst may or may not contain a support selected from the group consisting of activated alumina, activated carbon, magnesia, zirconia, silica, molecular sieves or mixtures thereof.

 The synthesis of the catalyst-free catalyst can be carried out by a common coprecipitation method or by first co-precipitating and mixing some of the components, or by impregnation.

 The supported catalyst may be either a general impregnation method or may be physically mixed with the support after the main catalyst has been precipitated and dried.

 The methanol feed space velocity is 0.01 to 10 grams of alcohol per gram of catalyst per hour, preferably 0.1 to 5 grams of alcohol per gram of catalyst per hour.

 The reaction temperature is 150 to 450 ° C, preferably 250 to 350 ° C, more preferably 250 to 300 ° C. The reaction pressure is from l to 40 bar, preferably from 1 to 10 bar, more preferably from 1 to 5 bar. The reaction pressure can also be a negative pressure.

The reaction is carried out in a fixed bed reactor, preferably a tubular reactor, and the heat required for the reaction is provided by steam or hot oil. In the following examples, a single O45x3x4000 mm reaction tube was used, and the heat required for the reaction was provided by hot oil outside the tube. The reaction time in the following examples was not less than 10 hours. After the reaction, the liquid phase material was collected, and the components were determined by gas chromatography using an internal standard method, and the internal standard was butyl acetate. The materials not mentioned in the liquid phase in the examples are methylamine, dimethylamine, trimethylamine, methylamine, dimethylamine and trimethylamine which can be returned to the reactor and further mixed with the raw materials to further produce acetonitrile or ethanol. In Example 6 to Example 16, the ratio of methanol to ammonia was 1: 1. Example 1

 The raw material is selected from the concentration of 95% methanol, containing 5% water, the other raw material is liquid ammonia, the molar ratio of methanol to ammonia is 2: 1, the reaction temperature is 275 ° C, the reaction pressure is 5 bar, and the composition of the catalyst is 15% copper. , 20% aluminum, 10% zirconium, 25% zinc, 30% titanium, 4.2kg of catalyst, air space of alcohol feed 0.5g alcohol per gram of catalyst per hour, ie 2.1kg/h, ammonia feed At 2 kg/hour, the reaction results showed that the single pass conversion of methanol was 40%, the selectivity of acetonitrile was 80%, and the selectivity of ethanol was 5%. Example 2

 The concentration of the raw material is anhydrous methanol, the other raw material is saturated ammonia water, the molar ratio of methanol to ammonia is 0.1: 1, the reaction temperature is 300 ° C, the reaction pressure is 2 bar, the composition of the catalyst is copper 15%, aluminum 20%, zirconium 10 %, zinc 25%, titanium 30%, 4.1 kg charged catalyst, the space velocity of the alcohol feed is 2 g alcohol per gram of catalyst per hour, SP 8.2 kg / h, the feed amount of ammonia water is 4 kg / hour, the reaction result It was shown that the single pass conversion of methanol was 100%, the selectivity of acetonitrile was 99.5%, and the selectivity of ethanol was 0.5%. Example 3

 The raw material is selected from the concentration of 80% methanol, containing 20% water, the other raw material is liquid ammonia, the molar ratio of methanol to ammonia is 1: 1, the reaction temperature is 250 ° C, the reaction pressure is lbar, and the composition of the catalyst is 45% copper. , zirconium 5%, zinc 50%, loading catalyst 4.2kg, alcohol feed rate of 0.5 grams of alcohol per gram of catalyst per hour, ie 2.1kg / h, liquid ammonia feed amount of 2kg / hour, reaction results It was shown that the single pass conversion of methanol was 90%, the selectivity of acetonitrile was 80%, and the selectivity of ethanol was 0.2%. Example 4

The raw material is selected from 50% methanol, 50% water, the other material is liquid ammonia, the molar ratio of methanol to ammonia is 4:1, the reaction temperature is 280 ° C, the reaction pressure is 5 bar, and the composition of the catalyst is 30% copper. , aluminum 10%, zirconium 45%, zinc 15%, loading catalyst 4.1kg, alcohol feed air velocity is 5 grams of alcohol per gram of catalyst per hour, ie 20.5kg / h, liquid ammonia feed amount is 10kg / hour, After 1000 hours of reaction, the reaction results showed that the single pass conversion of methanol was 25%, the selectivity of acetonitrile was 50%, and the selectivity of ethanol was 2%. Example 5

 The raw material is methanol, the other raw material is liquid ammonia, the molar ratio of methanol to ammonia is 10: 1, the reaction temperature is 450 ° C, the reaction pressure is 40 bar, the composition of the catalyst is 25% copper, 40% aluminum, 20% gold, 镧15 %, the carrier is ZSM-5 molecular sieve, 5kg of catalyst is charged, the space velocity of methanol feed is 10g alcohol per gram of catalyst per hour, ie 50kg/h, the feed amount of ammonia is 10kg/hour, the reaction result shows that methanol The conversion per pass is 10%, the selectivity to acetonitrile is 10%, and the selectivity for ethanol is 25%. Example 6

 The raw material is selected from methanol containing 5% water, the other raw material is ammonia gas, the reaction temperature is 150 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 30% copper, 45% zirconium, 10% palladium, 10%, 5% zinc, the carrier is Activated carbon, 4.5 kg of catalyst is charged, the space velocity of the feed of n-butanol is 0.01 g of alcohol per gram of catalyst per hour, that is, 0.045 kg / h, and the feed amount of ammonia is 0.05 kg / hr. The reaction result indicates that one way of methanol The conversion was 8%, the selectivity to acetonitrile was 95%, and the selectivity for ethanol was 0.2%. Example 7

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 280 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 45% copper, 30% zirconium, 5% aluminum, 10% titanium, 15% zinc, and the carrier is silica. 4.5 kg of catalyst was charged, the feed rate of methanol was 1 gram of alcohol per gram of catalyst per hour, that is, 4.5 kg / h, and the feed amount of ammonia was 2 kg / hr. The reaction result showed that the single pass conversion of methanol was 95%, acetonitrile selectivity of 42%, ethanol selectivity of 3%. Example 8

The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 30% copper, zirconium 35%, aluminum 15%, zinc 20%, the carrier is magnesium oxide, and the loading catalyst is 4.5kg. The methanol feed rate is 2 grams of alcohol per gram of catalyst per hour, ie 9 kg / h, The feed amount of ammonia was 4 kg/hr, and the reaction results showed that the single pass conversion of methanol was 90%, the selectivity of acetonitrile was 88%, and the selectivity of ethanol was 0.03%. Example 9

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 40% copper, 25% zirconium, 20% aluminum, 15% titanium, the carrier is magnesium oxide, and the catalyst is 4.5 kg. The methanol feed rate is 2 grams of alcohol per gram of catalyst per hour, ie 9 kg / h, and the ammonia feed is 4 kg / hour. The reaction results show that the single pass conversion of methanol is 91%, the selectivity of acetonitrile At 85%, the ethanol selectivity is 0.1%. Example 10

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 40% copper, 20% zinc, 20% aluminum, 20% titanium, the carrier is activated carbon, and the loading catalyst is 4.5kg. The feed rate of methanol feed is 4 grams of alcohol per gram of catalyst per hour, ie 18 kg / h, and the feed of ammonia is 5 kg / hour. The reaction results show that the single pass conversion of A is 75%, and the selectivity of acetonitrile is 80%, the ethanol selectivity is 0.1%. Example 11

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 40% copper, 20% zinc, 20% aluminum, 20% titanium, the carrier is silica, and the catalyst is 4.5. Kg, the feed rate of methanol is 4 grams of alcohol per gram of catalyst per hour, ie 18kg / h, the feed of ammonia is 5kg / hour, the reaction results show that the single pass conversion of methanol is 25%, the choice of acetonitrile The sex is 85% and the ethanol selectivity is 0.1%. Example 12

The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 40% copper, 10%, aluminum 20%, titanium 40%, loading catalyst 4.5kg, methanol feed. The space velocity is 4 g of alcohol per gram of catalyst per hour, that is, 18 kg / h, and the ammonia feed amount is 5 kg / hr. The reaction results show that the single pass conversion of methanol is 65%, the selectivity of acetonitrile. At 80%, the ethanol selectivity is 0.1%. Example 13

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 40% copper, ^ 10%, aluminum 20%, titanium 40%, the carrier is zirconium dioxide, and the catalyst is 4.5. Kg, the feed rate of methanol is 4 grams of alcohol per gram of catalyst per hour, ie 18 kg / h, the feed of ammonia is 5 kg / hour, the reaction results show that the single pass conversion of methanol is 65%, the choice of acetonitrile The sex is 80%, and the ethanol selectivity is 0.1%. Example 14

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 30% copper, 10% palladium, 60% magnesium, the carrier is zirconium dioxide, 4.5 kg of catalyst, methanol The feed space velocity is 4 g of alcohol per gram of catalyst per hour, that is, 18 kg/h, and the ammonia feed amount is 5 kg / hr. The reaction results show that the single pass conversion of methanol is 65%, and the selectivity of acetonitrile is 90%. , the ethanol selectivity is 0.1%. Example 15

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is 30% copper, ^ 10%, magnesium 30%, zirconium 30%, the carrier is ZSM-5 molecular sieve, and the catalyst is packed. 4.5kg, the feed rate of methanol feed is 4g alcohol per gram of catalyst per hour, ie 18kg/h, and the feed amount of ammonia is 5kg/hour. The reaction result shows that the single pass conversion of methanol is 65%, acetonitrile The selectivity was 85% and the ethanol selectivity was 0.1%. Example 16

 The raw material is methanol, the other raw material is liquid ammonia, the reaction temperature is 300 ° C, the reaction pressure is 1 bar, the composition of the catalyst is copper 30%, zinc 10%, magnesium 20%, aluminum 20%, titanium 20%, carrier is activated carbon, filling The catalyst has a space velocity of 4.5 kg, the feed rate of methanol is 4 g of alcohol per gram of catalyst per hour, that is, 18 kg/h, and the feed amount of ammonia is 5 kg/hr. The reaction result shows that the single conversion of methanol is 75%, acetonitrile. The selectivity is 70% and the ethanol selectivity is 0.1%.

Claims

 Claims  A method for preparing acetonitrile and/or ethanol by reacting methanol with ammonia in the presence of a solid catalyst comprising copper or copper oxide as a main component, comprising the steps of: methanol and ammonia entering a packed copper or copper A reactor in which a catalyst is a main component, a dehydrogenation reaction is carried out to produce acetonitrile and/or ethanol, water and hydrogen, and the reacted mixture is separated to obtain a product of acetonitrile or ethanol, wherein a molar ratio of methanol to ammonia is 0.1. ~10: 1.  2. The process according to claim 1, wherein the starting methanol is aqueous methanol. 3. The method according to claim 1, wherein the raw material ammonia is liquid ammonia or ammonia gas.  The method according to claim 1, wherein the catalyst has a copper content of 5 to 65% by weight, preferably 15 to 45% by weight.  5. The method of claim 4, said catalyst further comprising other components selected from the group consisting of ruthenium, gold, zirconium, palladium, aluminum, zinc, titanium, ruthenium, magnesium or oxides thereof.  6. A process according to claim 1 wherein said catalyst is supported on a support selected from the group consisting of activated alumina, activated carbon, magnesia, zirconia, silica, molecular sieves or mixtures thereof.  7. The method according to claim 1, wherein the molar ratio of methanol to ammonia is from 0.5 to 4:1. The method according to claim 1, wherein the reaction temperature is 150 to 450 ° C, preferably 250 to 350 °C. 9. The method according to claim 1, wherein the reaction raw material can be added to no more than methanol Steam heating, the reaction mixture contains acetonitrile and / or ethanol, unreacted methanol, ammonia and by-product water, hydrogen, and intermediates dimethyl ether, methyl formate, methylamine, etc., condensed into a gas-liquid separator The gas phase enters the gas separation process, and the liquid phase enters the liquid separation process to produce acetonitrile, unreacted ammonia and methanol, and intermediates or back to the reactor, or for other uses.  11. Process according to claim 10, characterized in that the methanol feed space velocity is from 0.01 to 10 grams of methanol per gram of catalyst per hour, preferably from 0.1 to 5 grams of methanol per gram of catalyst per hour.  12. The process according to claim 10, wherein the starting methanol can be aqueous methanol. 13. The method according to claim 10, wherein the raw material ammonia is liquid ammonia or ammonia gas. The method according to claim 10, wherein said catalyst has a copper content of 5 to 65% by weight, preferably 15 to 45% by weight.  15. The method of claim 10, said catalyst further comprising other components selected from the group consisting of ruthenium, gold, zirconium, palladium, aluminum, zinc, titanium, ruthenium, magnesium or oxides thereof.  16. A process according to claim 10 wherein said catalyst is supported on a support selected from the group consisting of activated alumina, activated carbon, magnesia, zirconia, silica, molecular sieves or mixtures thereof.  17. The method according to claim 10, wherein the molar ratio of methanol to ammonia is 0.5 to 4: l o  The method according to claim 10, wherein the reaction temperature is from 150 to 450 ° C, preferably from 250 to 350 ° C. 19. The method according to claim 10, wherein no more than methanol can be added to the reaction raw material 1.5 times the mole of oxygen