RU2337914C1 - Long-chain alkylphosphonic acids as soft steel corrosion inhibitors and their production - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to phosphoroorganic chemistry, namely, to method of obtaining long-chain alkylphosphonic acids, possessing anticorrosion activity, based on α-olefins of industrial fraction C₁₆-C₁₈ and C₂₀-C_26. Invention can be applied for protection of pipelines, reservoirs, construction metallic structures, equipment for extraction, transportation and processing oil and gas, in metal processing. Long-chain alkylphosphonic acids are obtained by interaction of α-olefins of industrial fraction C₁₆-C₁₈ and C₂₀-C₂₆ with O,O-dimethylphosphorous acid in molar ratio 1:(1.0-2.0) in presence of benzoyl peroxide in amount of 1.0-5.0% of weight of dimethylphosphorous acid at 110-150°C during 10-12 hours in absence of solvent with further hydrolysis of intermediate higher O,O-dimethyl(alkyl) phosphonates with hydrochloric acid with heating, obtaining target product which represents mixture of long-chain alkylphosphonic acids.

EFFECT: elaboration of novel method of obtaining mixture of alkylphosphonic acids and soft steel corrosion inhibitor.

2 cl, 1 tbl, 3 ex

Description

The invention relates to organophosphorus chemistry, namely to long-chain alkylphosphonic acids of the general formula (Ia, b) having anticorrosive activity and obtained on the basis of α-olefins of industrial fractions C ₁₆ -C ₁₈ and C ₂₀ -C ₂₆

where alkyl = C _n H _{2n + 1} , n = 16, 18 (a),

n = 20, 22, 24, 26 (b).

The invention can be used in various industries, in particular, for the protection of pipelines, tanks, building metal structures, equipment for the extraction, transport and processing of oil and gas, and metalworking.

The lower analogues of the proposed long-chain alkylphosphonic acids obtained from C ₆ -C ₁₀ olefins are used as wetting agents, detergents, softeners, binding agents, additives for lubricating oils (Pudovik A.N., Guryanova I.V., Ishmaeva E.A. Addition reactions of phosphorus-containing compounds with a mobile hydrogen atom // Reactions and methods for the study of organic compounds / Edited by B.A. Kazansky, I.L. Knunyants, M.M.Shemyakin, N.N. Melnikov, book 19. / Chemistry. - M., 1968. - 848 p.)

Lower alkylphosphonic acids are known, obtained by reacting phosphorous acid with individual monoolefins (hexene-1, cyclohexene, octene-1, decene-1) in the presence of benzoyl peroxide at the boiling point of olefins (Griffin CE, Wells HJ // J. Org. Chem. 1959 V.24. P.2049; Griffin CE // J. Org. Chem. 1960. V.25, N3. - P.665-666). However, the yields of the target alkylphosphonic acids are low (18-23%), which is associated with the formation of telomeres as by-products as a result of the secondary addition of primary alkylphosphonic acids via a multiple C = C bond of olefins. Thus, the path to alkylphosphonic acids with direct phosphorylation of olefins with phosphorous acid is difficult.

It is known to obtain O, O-dialkyl esters of alkylphosphonic acids by the reaction of radical addition of O, O-dialkylphosphorous acids to olefins (Pudovik AN, Konovalova IV // Zhokh. 1959. V.29. No. 10. P.3342- 3346; Stiles AR, Vaughan WE, Rust FF // J. Am. Chem. Soc. 1958. V.80. N3. P.714-716; GB 694772, published 29.071953), (GB 660918, publ. 11/14/1951, patent US 4108889, publ. 19.11.1976). O, O-dialkyl esters of alkylphosphonic acids are used to produce the corresponding alkylphosphonic acids by hydrolysis with hydrochloric acid (patent GB 660918, publ. 11/14/1951) or by treating such esters with anhydrous hydrogen chloride or bromide, followed by hydrolysis of the resulting chloro or bromo-hydrogen hydrides of alkyl acids (patent US 4108889, publ. 11/19/1976).

However, no information was found in the literature on the preparation of long-chain alkylphosphonic acids based on the phosphorylation of α-olefins of industrial fractions C ₁₆ -C ₁₈ and C ₂₀ -C ₂₆ and their use as inhibitors of steel corrosion. The problem of developing an effective method for processing industrial higher α-olefins obtained from fractions of hydrocarbon feedstocks into practically useful products of oil refining is currently urgent in our country due to the accumulation of a huge amount of these α-olefins, which are characterized by low reactivity and are not found To date, rational use to create commercial products.

EFFECT: possibility of processing industrial fractions of α-olefins C ₁₆ -C ₁₈ and C ₂₀ -C ₂₆ into alkylphosphonic acids.

The technical result is achieved by the proposed method for producing mixtures of long-chain alkylphosphonic acids of the general formula (1a, b) based on a-olefins of industrial fractions C ₁₆ -C ₁₈ or C ₂₀ -C ₂₆

alkyl = C _n H _{2n + 1} , n = 16, 18 (a), n = 20, 22, 24, 26 (b).

The essence of the invention lies in the fact that α-olefins of industrial fractions C ₁₆ -C ₁₈ or C ₂₀ -C ₂₆ (TU 2411-067-05766801-97 and TU 2411-068-05766801-97 manufactured by OAO Nizhnekamskneftekhim) are subjected to interaction with O, O-dimethylphosphorous acid in a molar ratio of 1: (1.0-2.0) in the presence of benzoyl peroxide in an amount of 1.0-5.0% by weight of O, O-dimethylphosphorous acid at 110-150 ° C for 10-12 hours with stirring in the absence of solvent, followed by hydrolysis of intermediate higher O, O-dimethyl (alkyl) phosphonates with hydrochloric acid at 100-110 ° C for 6-9 hours at alternating stitching followed by evaporation of the reaction mixture to obtain a solid product containing a mixture of long chain alkylphosphonic acids C ₁₆ H ₃₃ P (O) (OH) ₂ and C ₁₈ H ₃₇ P (O) (OH) ₂ or a mixture of C ₂₀ H ₄₁ P (O ) (OH) ₂ , C ₂₂ H ₄₅ P (O) (OH) ₂ , C ₂₄ H ₄₉ P (O) (OH) _2, and C ₂₆ H ₅₃ P (O) (OH) _2, respectively. For the synthesis of the target products, intermediate O, O-dimethyl (alkyl) phosphonates can not be purified, which increases the manufacturability of the proposed method for producing long-chain alkylphosphonic acids (I), which were tested for anticorrosion activity without purification.

A gas chromatographic analysis of the composition of the starting olefins of the industrial fraction C ₁₆ -C ₁₈ shows that this fraction contains only hydrocarbons with an even number of carbon atoms, and the total content of olefins of series C ₁₆ and C ₁₈ is 98%. In the C ₁₆ -C ₁₈ fraction, there are 2 bushes of peaks with retention times of 9.67-10.40 min of composition C ₁₆ with mass number 222 and 12.01-12.68 min of composition C ₁₈ with mass number 252. Moreover, the ratio of the peaks of olefins with masses of C ₁₆ and C ₁₈ is 3: 2. According to chromatograms and mass spectra, it was found that the total content of α-olefins in the C ₁₆ -C ₁₈ fraction is 80%. According to ¹ H NMR spectra, the total content of α-olefins in the C ₁₆ -C ₁₈ fraction is not less than 82%. The rest is olefins with an internal bond C = C.

The mass distribution in gas chromatograms of the C ₂₀ -C ₂₆ fraction shows that this fraction contains mainly olefins of the C ₂₀ , C ₂₂ , C ₂₄ and C ₂₆ series in a ratio of 48.6: 21.0: 14.6: 8.6%. The rest falls on olefins of series C ₁₈ and C ₂₈ . According to ¹ H NMR spectra, the total content of α-olefins in the C ₂₀ -C ₂₆ fraction is at least 85%. Thus, a significant content of α-olefins in the fractions C ₁₆ -C ₁₈ and C ₂₀ -C ₂₆ determines a high yield of target products.

The invention is illustrated by the following examples.

Example 1. Long-chain alkylphosphonic acids (1a) based on the reaction of α-olefins of the C ₁₆ -C ₁₈ fraction with O, O-dimethylphosphorous acid in a 1: 1 ratio.

A mixture of 33.5 g (140.0 mmol) of olefins of industrial fraction C ₁₆ -C ₁₈ , 15.5 g (140.9 mmol) of O, O-dimethylphosphorous acid and 0.4 g (1.7 mmol, 2.6% by weight of O, O-dimethylphosphorous acid) of benzoyl peroxide is heated 10 -12 hours at 130-140 ° C with stirring. The mixture was washed with water, the organic layer was separated and evaporated in vacuo. Unreacted olefins are distilled off from the residue in vacuo. The residue gives 33.6 g of a solid, which is diluted with 70 ml of concentrated hydrochloric acid and heated for 6-8 hours with stirring at 100-110 ° C. The solution was evaporated in vacuo. The residue gives 27.3 g (81%) of solid alkylphosphonic acids (Ia) with mp 60 ° C, acid number 139. IR spectrum (KBr, ν, cm ^-1 ): 2921 s, 2852 s ν (CH ₃ as, s; CH ₂ as, s); 2750 cf. w, 2738 cf. w ν (O-H); 2298 cf. about. w ² γ (OH); 1720 cf. about. w, 1640 cf. about. w δ (OH); 1129 about from. w ν (P = O); 1000 about. with ν [P-O (H)]. ¹ H NMR spectrum (600 MHz, CDCl ₃ , mixture of homologs and isomers, δ, ppm, J, Hz): 0.85 (t, 3H, CH ₃ C, ³ J _HH 7.1); 1.28 [m, 28H, C (CH ₂ ) ₁₄ CP; 32H, C (CH ₂ ) ₁₅ CP]; 1.39-1.76 (m, 2H, C-CH ₂ P); 9.21 [ears. m; 2H, P (OH) ₂ ]. Nuclear Magnetic Resonance Spectrum ³¹ P (C ₆ H ₆ , δ _P , ppm): 37.1. Mass spectrum (EU), m / z (I _rel ,%): 306.3 [M] ⁺ (13) and 334.3 [M] ⁺ (5).

Found,%: C 64.71; H, 11.61; R 9.37. C ₁₆ H ₃₅ O ₃ P and C ₁₈ H ₃₉ O ₃ R.

Calculated,%: C 62.60 and 64.60; H 11.54 and 11.78; R 10.11 and 9.26. M 306.3 and 334.4.

Example 2. Long-chain alkylphosphonic acids (Ia) based on the reaction of α-olefins of the C ₁₆ -C ₁₈ fraction with O, O-dimethylphosphorous acid in a ratio of 1: 2.

A mixture of 100.0 g (419.5 mmol) of olefins of industrial fraction C ₁₆ -C ₁₈ , 87.3 g (793.6 mmol) of O, O-dimethylphosphorous acid and 0.9 g (6.2 mmol, 1.0% by weight of O, O-dimethylphosphorous acid) of benzoyl peroxide is heated 12 h at 110-120 ° C with stirring. The mixture was washed with water, the organic layer was separated and evaporated in vacuo. The residue gives 120.5 g of a solid, which is diluted with 250 ml of concentrated hydrochloric acid and heated for 8 hours with stirring at 100-110 ° C. The solution was evaporated in vacuo. The residue gives 110.5 g (87%) of solid alkylphosphonic acids (Ia) with mp 59-61 ° C. The data of IR, NMR ¹ H, ³¹ P and mass spectra correspond to the spectra of the sample compound (Ia) obtained in example 1.

Found,%: C 63.55; H 11.56; R 9.77. C ₁₆ H ₃₅ O ₃ P and C ₁₈ H ₃₉ O ₃ R.

Calculated,%: C 62.60 and 64.60; H 11.54 and 11.78; R 10.11 and 9.26. M 306.3 and 334.4.

Example 3. Long-chain alkylphosphonic acids (Ib) based on the reaction of α-olefins of the C ₂₀ -C ₂₆ fraction with O, O-dimethylphosphorous acid in a 1: 1 ratio.

A mixture of 146.5 g (454.3 mmol) of olefins of industrial fraction C ₂₀ -C ₂₆ , 50.0 g (454.5 mmol) of O, O-dimethylphosphorous acid and 5.5 g (22.7 mmol, 5.0% by weight of O, O-dimethylphosphorous acid) of benzoyl peroxide is heated 10 h at 140-150 ° C with stirring. The mixture was washed with water, the organic layer was separated and evaporated in vacuo. Unreacted olefins are distilled off from the residue in vacuo. The residue was diluted with 240 ml of concentrated hydrochloric acid and heated for 9 hours with stirring at 100-110 ° C. The solution was evaporated in vacuo. 136.8 g (75%) of solid alkylphosphonic acids (Ib) are obtained in the residue as a paste. IR spectrum (KBr, ν, cm ^-1 ): 2923 s, 2854 s ν (СН ₃ as, s; СН ₃ as, s); 2744 cf. w, 2735 cf. w ν (O-H); 2356 cf. about. w ² γ (OH); 1723 cf. w, 1695 cf. w δ (OH); 1378 cf δ (CH ₃ s); 1128 s. w ν (P = O); 1005 about. with ν [P-O (H)]. ¹ H NMR spectrum (400 MHz, D ₂ O, mixture of homologs and isomers, δ, ppm, J, Hz): 0.90 (t, 3H, CH ₃ C, ³ J _HH 7.3); 1.29 (m, SSNA); 1.93 (m, 2H, CCH ₂ P); 8.10 [m; 2H, P (OH) ₂ ]. ³¹ P NMR spectrum (С ₆ Н ₆ , δ _P , ppm): 33.1, 33.8 and 36.2 in the ratio 1: 143: 1.

Found,%: C 68.37; H 12.41; P 6.97. C ₂₂ H ₄₇ O ₃ P, C ₂₀ H ₄₃ O ₃ P, C ₂₄ H ₅₁ O ₃ P and C ₂₆ H ₅₅ O ₃ R.

Calculated,%: C 66.23, 67.62, 68.82 and 69.87; H 11.98, 12.16, 12.31 and 12.44; P 8.55, 7.93, 7.40 and 6.94.

The obtained samples of long-chain alkylphosphonic acids were tested as carbon dioxide corrosion inhibitors of mild steel using an electrochemical cell with sparging of carbon dioxide in the presence of a surfactant (neonol) or in its absence (working electrodes MS-R-101S Pattern 44B, comparison electrode Ag / AgCl, pH -electrode, temperature sensor, Luggin capillary, openings for carbon dioxide inlet and gas outlet, the composition of the aggressive medium is based on a standard solution of ASTM D1144, which includes 24.5 g / l NaCl (98.8%), 0.66 g / l KCl (98.3%), 0.2 g / l NaHCO ₃ (98.0%), 5.2 g / l MgCl ₂ (98.5%), 1.16 g / l CaCl ₂ (98.3%) and 4.09 g / l Na ₂ SO ₄ (98.3%), in accordance with standard methods (Griffith R. // J. Petroleum Tech. - 1984. - Vol.36, No.3. - P.361-367; Brill JP // J. Petroleum Tech. - 1987. - Vol.39, No.1. - P.15-21). Samples of the compounds were introduced into a standard solution when using a single-phase system, either into a layer of kerosene or into a layer of a standard solution when using a two-phase system, the organic / inorganic layers in a ratio of 1: 9. It was found that at a concentration of 10 mg / l, compounds (Ia) inhibit mild steel corrosion by 99.5% 6 hours after the introduction of the inhibitor in the absence of neonol (see table). In the environment of produced produced waters taken from well No. 1010 of the Zyuzeyevsky field of the Republic of Tatarstan, the inhibitory activity of compounds (Ia) is 94.6% with respect to mild steel.

Thus, long-chain alkylphosphonic acids obtained on the basis of higher industrial α-olefins are an effective corrosion inhibitor and the inventive method for their preparation solves the problem of recycling production waste into practically useful products.

Test data for anticorrosive activity of long chain alkylphosphonic acids (Ia) with respect to mild steel Dose, mg / L Additive surfactant, neonol Aggressive environment P,%, 6 h P,%, 16 h γ, 6 h γ, 16 h 10 Standard solution 99.5 99.7 186.4 341.7 10 3 mg / l Standard solution 98.0 99.2 51.3 120.6 10 Standard solution / kerosene ^a 46.7 1.9 10 3 mg / l Standard solution / kerosene ^a 29.4 1.4 2.5 Standard solution 96.0 97.4 25.3 36.6 2.5 3 mg / l Standard solution 96.6 98.3 29.3 60.3 2.5 3 mg / l Standard solution / kerosene ^b 38.0 38.0 1.6 1.6 10 Standard solution 98.8 99.2 82.0 120.6 10 Formation water 94.6 18.6 10 3 mg / l Formation water 86.3 7.3 Notes:
P - inhibitory activity,%;
γ is the coefficient of inhibition.
^a Insertion of an inhibitor into the standard solution layer;
^b Injection of an inhibitor into the kerosene layer.

Claims (2)

1. A method of producing mixtures of long-chain alkylphosphonic acids from α-olefins of industrial fractions C ₁₆ -C ₁₈ and C ₂₀ -C ₂₆ , which includes a) the interaction of α-olefins of industrial fraction C ₁₆ -C ₁₈ or C ₂₀ -C ₂₆ s O, O-dimethylphosphorous acid in a molar ratio of 1: (1.0-2.0) in the presence of catalytic amounts of benzoyl peroxide, taken in an amount of 1.0-5.0% by weight of O, O-dimethylphosphorous acid, at 110- 150 ° C for 10-12 hours with stirring in the absence of solvent, followed by washing with water the organic layer and distillation unreacted of olefins to produce higher intermediate O, O-dimethyl (alkyl) phosphonates; b) hydrolysis of intermediate higher O, O-dimethyl (alkyl) phosphonates with concentrated hydrochloric acid at 100-110 ° C for 6-9 hours with stirring, followed by evaporation of the reaction mixture to obtain a solid residue. 2. A product containing a mixture of long chain alkylphosphonic acids C ₁₆ H ₃₃ P (O) (OH) ₂ and C ₁₈ H ₃₇ P (O) (OH) ₂ or a mixture of C ₂₀ H ₄₁ P (O) (OH) ₂ , C ₂₂ Н ₄₅ Р (O) (ОН) ₂ , С ₂₄ Н ₄₉ Р (O) (ОН) ₂ and С ₂₆ Н ₅₃ Р (O) (ОН) ₂ , obtained by the method according to claim 1 from α-olefins of industrial fraction C ₁₆ -C ₁₈ or C ₂₀ -C ₂₆ , respectively, as an inhibitor of mild steel corrosion.