SU992510A1 - Process for preparing naphthenic acids - Google Patents

Description

(5) METHOD FOR OBTAINING NAFTENOV14X

one

The invention relates to an improved method for producing acids.

Naphthenic acids are used in the paint industry to produce alkyd resins and dryers and in the process of producing cobalt

catalyst for oxosynthesis.

A known method for producing crude high molecular weight synthetic naphthenic acids by the oxidative processing of a petroleum product consisting of 30 mineral oil, lO petrolatum SP and 3 oi petrolatum distillate. The petroleum product chosen to produce naphthenic acids has an acid number of 32.2 mg KOH / G and a saponification number of 88.2 mg KOH / G before oxidation. According to this method, the feedstock is subjected to oxidation at 150 ° C, an air supply of 0.25 m3 / / h for 32 hours in the presence of a catalyst — potassium permanganate, taken in an amount of 0.2 wt.% To the feedstock. ACID

The resulting oxidate is washed with an aqueous solution of alkali at, and then, from the saponified oxidate, extraction is carried out by extraction of the unstable compounds. Alkaline salts of acids are cleaved with sulfuric acid and a mixture of raw acids is obtained with a yield of 2.6 and the quality of meeting the requirements of GOST for crude naphthenic acids Clj. The crude acids obtained by this method do not satisfy the requirements of modern GOST 13302-67. In addition, the crude acids obtained by this method are a complex mixture of polyfunctional oxygen-containing compounds, which contain MONO-, di- and polybasic acids of aromatic, naphthenic and fatty series and their hydrogenation products, such as hydroxy acids, ether acids, keto acids , lactones, lactides,

In the oxidation process, a finely dispersed heterogeneous catalyst is used — potassium permanganate, which is not selectively used for the preparation of naphthenic acids. Technique is complicated. The closest to the proposed technical essence and the achieved effect is a method for producing distilled naphthenic acids that meet the requirements of GOST 13302-67. The known method is carried out as follows. The fraction of oil, in most cases, the fraction of diesel fuel is neutralized with an aqueous solution of alkali at 35-75 ° C. Mechanically sludge separates unwashed compounds. Alkaline salts of acids under heat treatment at 350-360 ° C with simultaneous distillation of water and the remaining chemical compounds in them in the form of vapors with further condensation and separation of the latter into components. After heat treatment, the salts of the acids are acidified with sulfuric acid and, after washing to neutral conditions and drying at 120 ° C, the acids are subjected to distillation with the selection of a fraction that meets the quality requirements of GOST 13302-67. The yield of the target fraction is 0.12-0.18% by weight, based on the initial petroleum fraction 2. The production of naphthenic acids by this method is associated with the following disadvantages: the yield of the desired product is low. The fraction of the target acids does not have a constant composition. According to the technological scheme of the process, a complex coil-fired thermal furnace operating at high temperatures (350 ° C) is used to extract the unqualified compounds from the alkaline solution of the process; during the distillation of a mixture of naphthenic acids, partial decarboxylation proceeds, as a result of which distilled acids are enriched in unsaturated compounds, which, in turn, impairs the quality of the target product. Distilled naphthenic acids have a dark color and an unpleasant smell. In addition, due to the low content of naphthenic acids in oils, this method cannot fully satisfy the needs of 14 national households. The purpose of the invention is to increase the yield and improve the quality of the target product. This goal is achieved in that, according to the method for producing naphthenic acids, which consists in the fact that the fraction of naphthenic concentrate with boiling point. 250-350 ° C and indicators: mol.m. , d 0.8520-0.8560, ip 1, 6-1, 7 ,. and containing: aromatic hydrocarbons 0.1-23 ;, naphthenes 70-75; paraffins 23-28% - are subjected to selective oxidation at 135, air consumption 0.06-0, Ob1 kg / / KGch in the presence of a mixture catalizer manganese and potassium naphthenates, consisting of wt.% manganese naphthenate and 60-70 wt.% potassium naphthenate in the amount of 1.5-2 parts by weight of oxidizable concentrate, the oxidation time is usually 4 to 5 hours. In this mode, an oxidate is obtained with an acid number of 25–30 mg KOH / g and a content, weight: crude naphtha: a) 15-oh acid acids; hydroxy naphthenic acids 0.8-1.0; unwashed compounds 7880; water soluble substances 4 ,. It should be noted that the deviation from these parameters leads either to the inhibition of the acid-forming reaction or to the over-oxidation of the naphthenic acids formed to hydroxynaphthenic acids, or to the destruction of naphthenic acids to form undesirable by-products. The resulting oxidate is diluted with an inert solvent (gasoline Galosha, petroleum ether, light hydrocarbons, etc.), usually in weight. 1: 1 ratio and precipitate .oxynaphthenic acids. The oxidate solution is washed with an aqueous alkali solution, usually with an aqueous solution of sodium hydroxide with stirring for 1 hour, at the boiling point of the solvent. At the end of the saponification, the reaction mixture is usually settled, and the extractive solution of the ne1 x x compounds is separated from the aqueous solution of sodium salts of the acids and subjected to distillation. The distilled solvent is used during the second operation, and the unwashed compounds are returned to re-oxidation in a mixture with fresh naphthene concentrate. Diethyl sulfate is added to the aqueous solution of the sodium salts of the acids. The reaction of the alkylation of acids with diethyl sulfate is carried out with heating, usually at 90-95 ° C for 1, 5-2 hours and constant stirring. Then, from 59, an aqueous solution of sodium sulfate is separated, and the organic part is heated with stirring to ISOISO C. in order to free it from excess solvent and dry it from traces of water. The yield of ethyl esters is 9b-98% Dg per mixture of crude naphthenic acids. Dried ethyl ester crude on tenoich acids is subjected to vacuum distillation at 3 mm Hg and take the fraction. this fraction is 30-35 ppm by weight of the polyester tube, and it contains 60-65 weight. naphthenic acids. The fraction 75-170 ° C / 3 mm is saponified with an aqueous solution of alkali, usually an IOIS aqueous solution of caustic soda, at the same time distilling off the ethanol formed. The sodium salts of nslot are acidified with mineral acid (hydrochloric, sulfuric, phosphoric) and the desired naphthenic acids are isolated with indicators that meet the requirements of GOST 13302-67. The table shows the comparative data of synthetic naphthenic acids in accordance with the requirements of GOST 13302-67 on natural distilled naphthenic acids. Transparent Transparent Appearance is homogeneous on the liquid of the no-ningging liquid Content of naphthenic acids (weight,%), not less than 96, 5-97 more The content of unstable substances in terms of the organic part 0 Continued table Gves,), Not 1, 0-1.6 more Acidic miso in mg KOH per 1 g of naphthenic 220-260 230-260 acids Water content (wt.), no more No Color on an iodometric scale, no more The advantage of the proposed method is that naphthenic acids are obtained by selective catalytic oxidation naphthenic hydrocarbons; naphthenic acids from the oxidate are separated through their ethyl esters, which prevents decarboxylation of the acids during distillation; the process is waste-free, easy to implement and does not include sophisticated technological equipment; Naphthenic U1 SLOTS are obtained with high yield and improved indicators in comparison with acids obtained in the industry according to GOST 13302-67. The application of the proposed method allows to expand the resources of such valuable products as naphthenic slots,. P 1 and p 1, 200 kg of naphthene concentrate of Balakhani oil with indicators: mol, m, 224, d "0.855, I, i688, group hydrocarbon composition, wt%: aromatic hydrocarbons V, 6; naphthenes, n. paraffins 0.8; isoparafims 24 ,, are oxidized with air oxygen at 135140 ° С, air consumption is 0.06 kg / kg-hour, the amount of a mixture of manganese and potassium naphthenates is 1, 5 weight. per batch (the mixture consists of 35 wt.% manganese naphthenate, 65% potassium naphthenate). The process lasts 4.0 hours. 187.69 kg of the oxidate is obtained. The yield of oxidate is wt.% On raw materials, Oxidate is diluted with 190 kg of gasoline and sedimented 799.

1, 7 kg of hydroxynaphthenic acids (0.9 wt. relative to the weight of oxidate) are isolated. The gasoline oxidate solution was saponified with caustic soda, taken in the amount of 8.04 kg as a 10% aqueous solution at 80-90 ° C for 1 h, the gasoline extract of the unpurified compounds was separated by mechanical sludge and the product was distilled. 185.5 kg of gasoline are obtained, which is used in the second operation, and 148.28 kg of unmolded compounds, the yield of which is 70 weight relative to the weight of oxidate.

by re-oxidation.

A kg of diethyl sulfate is added to the aqueous solution of the sodium salts of the mixture of acids and the reaction is carried out directly. within 1 hour. After separation of the aqueous solution of sulfate; the mixture is kept at 150 ° C for 1.5 hours. As a result of alkylation, 29 kg of ethyl naphthenic acid ether (crude ester) are obtained.

The crude ether is distilled under a vacuum of 3 mm Hg. and select fraction 75170 C in the amount of 8.82 kg fr. 75170 ° C / 3 mm, washed with 1.3 kg of caustic soda, taken in the form of a 10% aqueous solution and at the same time distilled to obtain 2.9 kg of ethyl alcohol. The sodium salts of the target acids split 1 kg of phosphoric acid (sulfuric and. Hydrochloric acids can be taken and 5.7 kg of synthetic naphthenic acids can be recovered with the following indicators: acid value mg KOH / g; n2 ° 1.638, 300, 9b79, the content of neomyl compounds 1, 3%, color 20 mg 2 of a solution of 10% potassium iodide, degree of purity of naphthenic acids 96.5%; compare the number of carbon atoms in the molecule T, 07.

The naphthenic acid yield based on the naphthenic concentrate is 2.73% by weight.

Example 2. 200 kg of naphthene concentrate of Balakhani oil, oil with indicators: mol.m. , d 0,856, njo 1 ,, group hydrocarbon composition, weight: aromatic hydrocarbons 1.98; naphthenes and paraffins 0.7; isoparaffins 22,42; oxidized with atmospheric oxygen at 1351 0 С, air consumption of 0.0b1 kg / kg.h, amount of a mixture of manganese and potassium naphthenates at 1.82 wt.% per load of 08

The center of the mixture consists of 30 wt. manganese naphthenate, 70% potassium naphthenate), Duration of oxidation D, 5 h. Obtain an oxidate in the amount of 190 kg, or 95 pounds per raw material. Oxidate is diluted with 190 kg of gasoline and 1.9 kg of hydroxynaphthenic acids (1 wt.% Relative to the weight of oxidate) are precipitated. The gasoline oxidate solution was saponified with caustic soda, taken in an amount of 8.12 kg as a 10-aqueous solution at 80-90 ° C for 1 hour. The gasoline extract of the unpurified compounds was separated by mechanical sludge and subjected to distillation. In this case, 185.7 kg of gasoline is obtained, which is used during the second operation, and 2 kg of neyl e # 1x compounds, the output of which is 78 in weight with respect to the weight of oxidate D.

15.82 kg of diethyl sulfate are added to the aqueous solution of sodium salts of the mixture of acids and reacted at 90-95 ° C for 1.5 hours. After separating the aqueous solution of sodium sulfate, the mixture is maintained at 155 ° C for 2 hours. Alkylation results in 29.7 kg of ethyl ester of a mixture of acids (ether),

The crude ether is distilled under a vacuum of 3 mm Hg about and 7 7 5 in the amount of 10.4 kg is taken, which is washed

1.7 kg of caustic soda, taken in the form of a 10% aqueous solution, and simultaneous distillation, 3 kg of ethyl alcohol are obtained.

The sodium salts of acids acidify with 2.1 kg of phosphoric acid (sulfuric and hydrochloric acids can be taken) and 6.76 kg of synthetic naphthenic acids are recovered with the following indicators: acid number 230 mg KOH / g, 1.4b49d O, 9698 ; the content of unwashed compounds 1.58%; purity of naphthenic acids 97%; color 22 mg 2 solution of 10% potassium iodide, cf. the number of carbon atoms in the molecule is 15.1.

Naphthenic acid yield on naphthenic concentrate is 3.33 wt.

Example 3. 200 kg of naphthenic concentrate of Balakhani oil with indicators: mol.m. 220, c1 0.852, 1.4610, group hydrocarbon composition, wt.%: Aromatic hydrocarbons 0.4; naphthenes 70.4; n. paraffins 1,2; isoparaffins 28 are oxidized with oxygen at 135

: 999

air flow rate 0, 0b kg / kg-h, the amount of a mixture of manganese and potassium naphthenate 1, 9b wt.% per. loading of the concentrate mixture consists of k O weight,% manganese naphthenate, 60 potassium naphthenate Duration oxidation -, 5 hours 189 kg (wt.% For raw materials). The oxidate is diluted with 189 kg of gasoline and 1.5 kg of hydroxynaphthenic acids (0.8 | with respect to the weight of oxidate) are precipitated. The gasoline solution of the oxidate was washed with caustic soda, taken in the amount of 8.02 kg as a 10% aqueous solution at 80–90 ° С for

1h The gasoline extract was separated mechanically by distillation of the e1x compounds and the product was subjected to distillation. In this case, 185.2 kg of gasoline and 151.2 kg of unwashed compounds are obtained, the yield of which is relative to

by weight, the oxidate is 80% by weight. 15.62 kg of diethyl sulfate are added to an aqueous solution of the sodium salts of the mixture of acids, and the reaction is carried out at 1.5 hours. The mixture is then kept at 1bO ° C for

2 hours after the separation of the aqueous solution of sodium sulfate. Alkylation results in 29.2 kg of an ethyl ester of a mixture of acids (ether).

Raw ether distilled under vacuum

3mmHg and get fr. 75-170 ° C 9, 3 kg.

Fr 1, i, 6 kg of caustic soda, taken in the form of a 10% aqueous solution, were washed, and 2.9 kg of ethyl alcohol were separated off by simultaneous distillation.

The sodium salts of acids acidify 1.6A kg of phosphoric acid and release 5.50 kg of synthetic naphthenic acids with the following indicators: acid number 2bO KOH / g; n 1.532 d 0.9528; the content of neomymal compounds 1.1%; the purity of naphthenic acids is 22 mg EO in 100 ml of a solution of 10% potassium iodide, the average number of carbon atoms in a molecule is 12.3.

The naphthenic acid yield on the naphthenic concentrate is 2.75-3.

As can be seen from the above examples, while maintaining the optimal process conditions, it is possible to obtain synthetic naphthenic acids with a yield of 2.73-3.33 wt.% To the feedstock. This yield is 18-22 times more than naphthenic content.

-,ten

Acids obtained in a known manner. In addition, the quality of synthetic naphthenic acids not only meets the requirements of GOST 13302-67. but the target product surpasses distilled naphthenic acids in color, content of unwashed compounds, and smell.

An example. 200 kg of naphthenic concentrate of balakhana oil with indicators: mol.m. 228; d 0,85b; n 1 ,, group hydrocarbon composition, wt.%: aromatic hydrocarbons 1,4; naphthenes 7.6; paraffins 24.0; oxidized with atmospheric oxygen at 135–1 ° C, air consumption O, Ob kg / kg “h, the amount of the mixture of metal naphthenates 2.5% by weight per concentrate load (the mixture consists of 35% by weight manganese naphthenate, 65% by weight of potassium naphthenate ), the oxidation time is 4.5 hours and an oxidate is obtained. The yield of oxidate is 9.85% by weight of the feedstock. The oxodate is diluted with 190 kg of gasoline and 0.2 kg of hydroxynaphthenic acids (0.1 wt.% Relative to the weight of oxidate) are precipitated. The gasoline solution of the oxidate is washed with caustic soda, taken in the amount of 3.98 kg as a 10-aqueous solution at 80 ° -E-0 ° C for 1 hour, the gasoline extract of the unwashed compounds is separated by mechanical sludge and subjected to distillation. This gives 185 kg of gasoline and 174.5 kg of unwashed compounds, the yield of which is 92 wt.% With respect to the weight of oxidate.

An equivalent amount of sulfuric acid is added to the aqueous solution of the sodium salts of the mixture of acids and 7.97 kg of crude acids are isolated, the yield of which to the weight of oxidate is 4.2 weight.

From the example it can be seen that a change in the amount of a mixture of manganese and potassium naphthenates by only 0.5 compared with the optimum reduces the yield of crude acids by a factor of about 4.

Claims (2)

Example 5. 200 kg of naphthene concentrate with indicators corresponding to those of the above examples are oxidized while maintaining the range of all parameters of example 1 except the ratio of naphthenates in the catalyst mixture. In this case, the catalyst mixture consists of 80% by weight of manganese naphthenates and by 2Q% of potassium naphthenates. In this way, 16 kg of the oxidate is obtained, the yield of which is 82 wtD per feed. The oxidate is diluted with 170 kg of gasoline and 29.5 to hydroxynaphthenic acids (18% by weight relative to the weight of oxidate) are precipitated. The gasoline oxidate solution was saponified with caustic soda, taken in an amount of 2.1 kg in the form of a 10% aqueous solution at 80-90 ° C for 1 h, the gasoline extract of the unpurified compounds was separated by mechanical sludge and subjected to distillation. In this case, 16 kg of gasoline and 101.68 kg of unwashed compounds are obtained, the yield of which is 62 weight relative to the weight of the co-acid; An equivalent amount of sulfuric acid is added to an aqueous solution of sodium salts of the mixture of acids and 10.17 / kg of crude acids are isolated, the yield of which is 6.2% relative to the weight of oxidate. From this example, it can be seen that increasing the amount of manganese naphthenate in the catalyst mixture disrupts the oxidation selectivity, as a result of which the naphthenic acids are re-acidified to hydroxy naphthenic and decompose to form low molecular weight products. In this example, the output of water-soluble compounds is 13.8% ., which is three times more than in the first three examples. Example 6 Experience run as in Example 1, changing the composition of the catalyst mixture (20 manganese naphthenate and 80% potassium naphthenate). An oxidate is obtained in the amount of 186 kg (90 per raw material). The oxidate consists of, weight: hydroxynaphthenic acids 0.02; crude naphthenic acids 2.4; unwashed compounds, R, 06; water-soluble compounds So, in this ratio of naphthenates, potassium naphthenate strongly inhibits the catalytic action of manganese naphthenate, as a result of which the yield of the target acids is much less than in the examples while maintaining the optimum ratio of the ratio of cocatalysts. Thus, it can be seen from the above examples that in order to selectively obtain naphthenic acids, it is necessary to strictly adhere to the optimal conditions for the process of oxidation of naphthenic concentrate. The fraction of synthetic naphthenic acids obtained by the proposed method meets the requirements of GOST 13302-67 .. It has been established that this fraction consists of 9b-97% by weight of monobasic monocyclic and bicyclic naphthenic acids with a predominantly cyclopentane acid content. It contains acids with an average number of carbon atoms in a molecule of 12-15. According to IR spectroscopy, this fraction contains acids bound to the carboxyl group through methylene groups. Claims method for producing naphthenic acids by treating an oil fraction comprising a neutralization step with an aqueous alkaline solution at elevated temperature, isolating unwashed compounds, isolating the product by acidifying with mineral acid, which, in order to increase the yield and improve the quality of the target product, naphthenic concentrate from t.kip, 250-350 C and indicators: mol. m. 220-2i 0; 61 0.852-0.856; P. ° 1.46-1.47 and containing 0.1-2% aromatic hydrocarbons; 70-75% naphthenic hydrocarbons; 23-28% of paraffins, subjected to oxidation with air at 135-l40 ° C, air consumption of 0.0b-0.0b1 kg / kg-h in the presence of a catalyst - a mixture of manganese naphthenate and potassium, consisting of 30-40 wt.% Naphthenate manganese and b6-70 wt.% potassium naphthenate, in the amount of 1, weight. the oxidized concentrate, the resulting oxidate is broken down with an inert solvent and hydroxynaphthenic acids are separated and then washed with an aqueous solution of alkali at the boiling point of the solvent and neo | 1 l of the 1st compound, and to the aqueous solution of salts. acids, diethyl sulfate is added and the alkylation reaction is carried out at elevated temperature, then the crude naphthenic acid ethyl ester is separated. 3 992510t and distilled it, taking the fraction .1. Copyright testimony of the USSR 75-170 ° С / 3 mm Hg, st., Obtained fraction-W 137515, cl. C 07 C 51/20, I960, the reaction is washed with an aqueous solution of alkali. 2. Kuliev A.M. and others. Naphthenic Sources of information, acids. M., Himi, 19b5, p. 86 taken into account in examination 5 (prototype).