The method of producing styrene

 

(57) Abstract:

The invention relates to the petrochemical industry and can be used in the process of joint production of propylene oxide and styrene. The inventive methylphenylcarbinol substance is subjected to liquid-phase catalytic dehydration at elevated temperature in the presence as catalyst of sulfuric acid, modified by the introduction of oxygen-containing organic compounds and/or nitrogen-containing compounds. As oxygen-containing organic compounds using ketone, alcohol, carboxylic acid, allenglish, ethers and esters derived from olefin oxides and methylphenylcarbinol, organic acids and phenols, and/or their mixture, and as a nitrogen-containing organic compounds using amines, aminoalcohols, the basis of manniche, oksihinolina-, alkyl-, dialkylhydroxylamines, hydrazine, pyridine, amides, such as formamide, alkylborane, dialkylphosphate, ndimethylacetamide, urea, sulphonamide, amigorena acid, their derivatives and/or mixtures thereof. Effect: increase the selectivity of formation of styrene, lower content of high-boiling products in the products Digi owano during the joint production of propylene oxide and styrene at a stage of dehydration methylphenylcarbinol (IFC) in styrene.

The number of known methods for producing styrene by using as catalysts mineral acids or their salts. So in the paper [Y. salkind, I. Berkovich, M. Amusin. The reservoir, mass, N2, 14, 1934], the results of dehydration IFC in the presence of KHSO4. This method consists in heating the IFC with 3-5 wt. % potassium bisulfate at 120-200oC with simultaneous distillation formed with a yield of 75% from theory of styrene. However, when testing this method in pausawasdi conditions, when applying practititioner carbinol outputs styrene averaged to 0.47-0.49 kg per kg of IFC. Thus was formed a large number of non-volatile VAT residue, the nature of which remained outstanding, and used as the catalyst potassium bisulfate settled on the walls of the apparatus in the form of a solid crust removal which required additional treatment with steam.

In [A. A., Vensat, A. C. Cohn. Journe. go active. chem., 1940, T. XIII, N12, S. 1873-1877], the results of dehydration IFC in the presence of soluble in the reaction mass of acid catalysts, which are used organic and inorganic acids, such as tetracoralla, p-toluensulfonate, sulfanilic, sulfur and phosphoramide aqueous solutions of different concentrations.

As a result of the research the authors found that dehydration IFC in the presence of organic acids gives satisfactory yields of styrene in the presence of a mixture of at least 5 wt.% tetrafluorophthalic acid or 2 wt. % sulfanilic acid and not less than 0.025 wt.% p-toluensulfonate acid, and the use of the latter allows to significantly reduce the reaction temperature.

Phosphoric acid is introduced in the amount of 0.25 to 4 wt.% gives low outputs styrene, decreasing with increasing amount of acid.

Dehydration IFC in the presence of sulfuric acid was held at relatively low temperatures with the formation of up to 80% of styrene in the presence of 0.015-0.03 wt.% the catalyst is introduced in the form of a weak aqueous solution. The increase in the content of acid in the carbinol in excess of 0.05% or decrease it to 0.0075 wt.% causes a reduction of the yield of styrene. But it should be noted that the present paper describes the dehydration clean IFC. When you try to use sulfuric acid as a catalyst dehydration faction IFC containing 65-85 wt.% the main product, 12-25 wt.% of acetophenone (ACP), up to 2 wt.% benzaldehyde and 0.5 to 6 wt. % heavy products (Fraction IFC such composition used in the process sovmeshchennom catalyst - aluminum oxide. in the range of concentrations of sulfuric acid specified in [2] , we established that the use of fractions IFC such composition is not possible to obtain an output of styrene decomposed carbinol above 60 mol.% due to the formation of large quantities of high-boiling products and ACF.

To eliminate the drawbacks associated with the use of sulfuric acid during dehydration faction IFC, we propose a method of liquid-phase catalytic dehydration methylphenylcarbinol substances at elevated temperatures in the presence as catalyst of sulfuric acid modified by the introduction of oxygen-containing organic compounds and/or nitrogen-containing compounds. As oxygen-containing organic compounds using ketone, alcohol, carboxylic acid, allenglish, ethers and esters derived from olefin oxides and methylphenylcarbinol, organic acids and phenols and/or their mixture, and as a nitrogen-containing organic compounds using amines, aminoalcohols, the basis of manniche, oksihinolina-, alkyl-, dialkylhydroxylamines, hydrazine, pyridine, amides, such as formamide, alkylborane, dialkylphosphate, ndimethylacetamide, urea, su the VA, you can use the faction IFC co-production of propylene oxide and styrene, contain a mixture of compounds of metals of constant valency 1A and/or 2A group 3 and/or 4-year periods of the periodic system, and iron taken in a total quantity in the calculation of the metal is not more than 0.01 wt.%. The dehydration can be carried out in a cascade of 2-5 reactor at a temperature of 110-220oC. the Catalyst serves as directly into the reactor and mixed with the source and/or return the products. The catalyst may be used in the form of solutions, suspensions or emulsions. Dehydration methylphenylcarbinol substances can be carried out in the presence of hydrogen.

In the case of the implementation process in a cascade of reactors or in a partitioned reactor, the catalyst may be supplied in the same thread with the raw materials, starting from the first reactor or the first section, or in each reactor or section separately.

Treatment of the catalyst with organic oxygen-containing and/or nitrogen-containing compounds, such as, for example, ketone, alcohol, carboxylic acid, allenglish, ethers, esters and polyesters derived from olefin oxides and IFC, organic acids and phenols and/or their mixture, and as a nitrogen-containing organic compounds used amim the AK formamid, alkylborane, dialkylphosphate, ndimethylacetamide, sulphonamide, amigorena acid and/or mixtures thereof allows to obtain an additional effect on increasing the selectivity and speed of the process and reduce the number of heavy products formed by placing the catalyst in the active complex.

The implementation of the process in the above conditions can improve the selectivity of the formation of styrene to reduce the content catalyzate of acetophenone and "heavy" products.

From literature is known about the use of a catalyst containing sulfuric acid, treated with an organic oxygen - and nitrogen-containing compounds in the process of obtaining styrene liquid-phase catalytic decomposition of IFC, which allows to make a conclusion about conformity of the present invention, the criteria of "novelty" and "inventive step". The possibility of using the proposed technical solutions in the industrial method of producing styrene shows the invention according to the criterion of "industrial applicability".

The claimed invention the following examples.

Example 1. Getting styrene carry out catalytic liquid-phase dehydration IFC when temperature is IOM 75 ml equipped with a stirrer, a downward and backward water and carbon dioxide refrigerators, receivers, fasoracetam, dosing systems and thermal management. Initial load of IFC in the flask with 75 ml Use IFC containing 81,07 wt.% the main product, 14,95 wt.% of acetophenone (ACP), to 0.66 wt.% benzaldehyde, or 0.11% of styrene, and 0.2% toluene and 2,96 wt. % heavy products, as well as within 0.00001 wt.% benzoate of iron, based on the metal, and 0.003 wt.% a mixture of hydroxide and sodium carbonate, based on the sodium. After reaching in the flask predetermined temperature, IFC served in the flask reactor at the rate of 400 ml/hour. Before feeding into the reactor at a fraction of the IFC introduce the catalyst is sulfuric acid in the form of a 5% aqueous solution at a ratio of 0.1 wt. % H2SO4and nitrogen-containing compound, which is used as dimethylformamide in the amount of 0.0005 wt.%. The experiment is carried out at atmospheric pressure. Duration of experience 1 hour.

At the exit of the reactor to receive the vapour phase of the reaction mass, which after condensation and cooling is divided in patristical on two layers: oil and water. The oil layer is analyzed for composition of gas-liquid chromatography. Acid in this layer determine what the actual content of the acid with an excess of aqueous alkali.

The bottom product of the reactor, which represents the liquid phase, after cooling, is collected in the collection and analyzed using the method of gas-liquid chromatography.

In the course of experience receive 327 ml oil layer, 44 ml of the aqueous layer and 93 ml of the bottom product of the reactor.

The analysis of the oil layer is installed, the content of styrene 77,9 wt.%, benzaldehyde is 0.37 wt.%, the acetophenone - 18,64 wt.%, IFC-1,73 wt.% 3.14 wt.% "heavy" products. The styrene content in the bottom product of the reactor was 25.1 wt.%.

Conversion methylphenylcarbinol is 98,1%. The output of styrene on the decomposed methylphenylcarbinol was 90,32 mol.%.

Example 2. Getting styrene carried out in a laboratory setup described in example 1 at a temperature of 220oC and atmospheric pressure. For experience use a fraction of the IFC, containing 85% the main component, 10.4 wt.% Act, 2,96 wt. % heavy products and the rest is the sum of products, including benzaldehyde, styrene-methylsterol, toluene and benzene. As an impurity fraction contains of 0.0004 wt. percent, based on the metal, a mixture of organic and inorganic compounds of sodium, calcium and iron, mainly in the form of hydroxides, benzoates and pinoleum in the reactor is mixed with a catalyst with sulfuric acid in amounts of 0.001 wt.% and with nitrogen - and oxygen-containing organic additives in the form 0,0003 wt.% oksihinolina and 0.001 wt.% polyether with a molecular weight of 300, derived from ethylene oxide and propylene oxide.

Conversion of IFC is 99,8%. The output of styrene decomposed IFC 85,6 mol.%.

Example 3. Getting styrene carried out in a laboratory setup described in example 1 at a temperature of 110oC and a residual pressure of 200 mm RT. post. For the experiment using the fraction containing 65 wt.% IFC, 28 wt.% ACP, 3.6 wt. % heavy products and the rest of benzene, toluene, styrene and benzaldehyde. As impurities in the fraction contains compounds of sodium and iron in the amount of 0.005 wt.% in the calculation of the metal. Faction impose a 10% aqueous solution of sulfuric acid in an amount of 0.1 wt.% in the calculation of the H2SO4, about 0.001 wt. % 2,6-ditretbutyl-4 dimethylaminomethylphenol (base manniche) and 0.01 wt.% simple ether MM=368 obtained by ethoxycarbonyl of Nonylphenol with ethylene oxide.

At the end of the experience revealed that the conversion of IFC is of 79.5%. The output of styrene decomposed IFC was 70.1 mol.%.

Example 4. The experience is conducted according to the recipe of example 2. Faction IFC impose a 20% aqueous solution of the catalyst in the amount of 0.5 wt.% in the calculation of sulfuric acid, of 0.025 wt.% urea is 0.05 wt.% a mixture of propylene glycols containing 60 wt. % monopropylene">

Temperature dehydration 150oC.

Conversion of IFC is 95.7%. The output of styrene reacted IFC 90.3 mol.%.

Example 5. The experience is conducted according to the recipe of example 2. Fraction IFC contains about 0.001 wt.% sodium benzoate. Faction IFC impose a 1% aqueous solution of the catalyst in the amount of 0.02 wt.% in the calculation of sulfuric acid, 0.005 wt.% the sulphonamide, 0.01 wt.% amide sulfuric acid, 0,0008 wt.% the research, 0.1 wt.% the mixture of esters and ethers IFC derived from IFC, propylene oxide and benzoic acid.

Temperature dehydration 190oC.

At the end of the conversion experience, the IFC was 97%. The output of styrene reacted IFC 78,02 mol.%.

Example 6. The experience is conducted according to the recipe of example 2. Fraction IFC contains about 0.001 wt. % potassium benzoate, 0,0003 wt.% benzoate Ca and 0,0003 wt.% benzoate of iron and 0.1 wt.% benzoic acid. Faction IFC impose a 3% aqueous solution of the catalyst in an amount of 0.01 wt.% in the calculation of sulfuric acid, 0.02 wt. % amide sulfuric acid, is 0.0002 wt.% triethanolamine, is 0.0002 wt.% naphtylamine.

Temperature dehydration 200oC.

Conversion of IFC is 95.4%. The output of styrene reacted IFC 95,1 mol.%.

Example 7. Experience Prov is the iron, 0.01 wt.% benzoic acid and 0.0005 wt.% diethylhydroxylamine. Faction IFC introduced to 29.4% aqueous solution of the catalyst in amounts of 1 wt.% in the calculation of the sulfuric acid, is 0.0002 wt.% ethylamine, is 0.0002 wt.% diethylamine.

Temperature dehydration 160oC.

Conversion of IFC is 95.4%. The output of styrene reacted IFC 95,1 mol.%.

Example 8. The experience is conducted according to the recipe of example 7. Faction IFC enter 10,0% aqueous solution of the catalyst in the amount of 0.25 wt.% in the calculation of sulfuric acid and 2 wt.% the cubic product separation of the reaction mass dehydration IFC styrene, consisting of 30 wt.% simple ether IFC, 15 wt.% of ester IFC and benzoic acid, 0.1 wt.% of ethylamine benzoate, 0.1 wt.% of phenol.

Temperature dehydration 180oC.

Conversion of IFC is to 86.4%. The output of styrene reacted IFC to 91.1 mol.%.

Example 9. The experience carried out in a cascade of three reactors with the charge, catalyst and additives as in example 8.

Conversion of IFC is 97,4%. The output of styrene reacted IFC br93.1 mol.%.

Example 10. The experience is conducted according to the recipe of example 7. As the source reagent is used IFC, containing 99% of the main component. Kata is ATM the catalyst is introduced into the reactor in the amount of 0.5 wt.% in the calculation of the sulfuric acid.

Temperature dehydration 140oC.

Conversion of IFC is to 96.9%. The output of styrene reacted IFC 94,5 mol.%.

Example 11. The experience is conducted according to the recipes of examples 7 and 10. As catalyst, use a 2% solution of sulfuric acid in IFC, additionally containing 0.2 wt.% of Nonylphenol. The catalyst introduced into the reactor in amounts of 0.05 wt.% in the calculation of the sulfuric acid.

Temperature dehydration 180oC.

Conversion of IFC is 89,8%. The output of styrene reacted IFC of 91.3 mol.%.

Example 12. The experience carried out in a cascade of three reactors with the charge, catalyst and additives as in example 8, in the presence of hydrogen fed to the reactor with a rate of 0.02 l/l hours.

Conversion of IFC is 98,7%. The output of styrene reacted IFC 98,1 mol.%.

Example 13. The experience is conducted according to the recipe of example 7. As the source reagent is used fraction IFC, containing 85% the main component. The catalyst is prepared by intensive mixing 10 wt.% an aqueous solution of sulfuric acid with a solution consisting of 10 wt.% of formamide, 70 wt.% IFC and 20 wt. % of acetophenone (ACP). Thus obtained catalyst in the form of the emulsion is introduced into the reactor in the amount of 0.0 to move styrene reacted IFC 93 mol.%.

Example 14. The experiment is carried out as in example 13. The catalyst consists of 5 wt.% sulfuric acid, 15 wt.% ethylformate, 2 wt.% stearic acid, 1 wt.% benzoic acid, the rest act.

Conversion of IFC to 94.3%. The output of styrene reacted IFC 92,2 mol.%.

Example 15. The experience carried out as in example 13. The preparation of the catalyst instead of ethylformate use ndimethylacetamide.

The reaction temperature 190oC.

Conversion of IFC 97%. The output of styrene reacted IFC of 97.8 mol.%.

Example 16. The experience carried out as in example 10. In the process of preparation of the catalyst instead of pyridine using hydrazine in the amount of 0.05 wt.%, in a mixture consisting of 20 wt.% phenol and 80 wt.% The IFC.

Conversion of IFC 97%. The output of styrene reacted IFC 94,8 mol.%.

Example 17. The experience carried out as in example 6. The preparation of the catalyst instead of triethanolamine use monopropellant in the number 0,0003 wt.%.

Conversion of IFC 96,1%. The output of styrene reacted IFC 94,6 mol.%.

Example 18. The experience carried out as in example 17. The catalyst is 20% of freshly prepared according to the recipe of example 17 and 80% of the cycle, representing CBM product once the Chille IFC to 95.3 mol.%.

Example 19. The experience carried out by the method of example 17. As the catalyst used, the suspension obtained under vigorous stirring, recycling cubic product separation of the reaction mass dehydration of experience 17, added in powder form to 0.01 wt.% urea and 0.06 wt.% amigorena acid.

Conversion of IFC 93.9 per cent. The output of styrene reacted IFC 94,8 mol.%.

These examples show that the use in the process of liquid-phase dehydration of methylphenylcarbinol in styrene proposed catalyst allows degidratiruth IFC with conversion to 99.8% when the styrene decomposed IFC to 95,1 mol.%.

1. The method of producing styrene liquid-phase dehydration methylphenylcarbinol substances at elevated temperatures in the presence as catalyst of sulfuric acid, characterized in that the catalyst used sulfuric acid that is modified by introduction of oxygen-containing organic compounds and/or nitrogen-containing compounds.

2. The method of producing styrene by p. 1, characterized in that as the oxygen-containing organic compounds using ketone, alcohol, carboxylic acid, allenglish, issues, and/or their mixture, and as a nitrogen-containing organic compounds using amines, aminoalcohols, the basis of manniche, oksihinolina-, alkyl-, dialkylhydroxylamines, hydrazine, pyridine, amides, such as formamide, alkylborane, dialkylphosphate, ndimethylacetamide, urea, sulphonamide, amigorena acid, their derivatives and/or mixtures thereof.

3. The method of producing styrene by PP.1 and 2, characterized in that as methylphenylcarbinol substance use fraction methylphenylcarbinol co-production of propylene oxide and styrene, containing in its composition a mixture of compounds of metals of constant valency 1A and/or 2A group 3 and/or 4-year periods of the periodic system, and iron taken in a total quantity in the calculation of the metal is not more than 0.01 wt.%.

4. The method of producing styrene by PP.1 to 3, characterized in that the dehydration is carried out in a cascade of 2 - 5 reactor at a temperature of 110 - 220oC.

5. The method of producing styrene by PP.1 to 4, characterized in that the catalyst is injected directly into the reactor and/or the source and/or return products in the form of solutions, suspensions or emulsions.

6. The method of producing styrene by PP.1 to 4, characterized in that the dehydration is carried out in

 

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