RU2378244C1 - Method for synthesis of higher fatty alcohols - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for synthesis of higher fatty acids which are widely used in the tobacco industry, in production of detergents, plasticisers, foam stabilisers, additives for lubricating oils, as well as for production of cosmetics. The method involves reaction of a C₁₀-C₁₈ hydrocarbon fraction with hydrogen peroxide in the presence of a solvent. The process is carried out at 20-50°C in molar ratio of the C₁₀-C₁₈ hydrocarbon fraction to hydrogen peroxide of (1.0 - 13.0) : 1, on a titanium-containing zeolite catalyst, taken in amount of 0.1 to 70 g/l of the reaction mass, which after the synthesis stage is subjected to atmospheric rectification to remove solvent, and vacuum rectification to separate unreacted C₁₀-C₁₈ hydrocarbon fraction returned to the synthesis stage in form of a distillate and commercial grade higher fatty alcohols. As a rule, the catalyst used is a titanium-containing zeolite with MFI, MEL topology or β-zeolite with titanium content from 0.1 to 9.5%.

EFFECT: obtaining higher fatty alcohols with high output with low energy consumption for their extraction.

2 cl, 1 tbl, 7 ex

Description

The invention relates to chemical technology, and in particular to methods for producing and isolating higher fatty alcohols (VZhS).

Alcohols of fractions C ₆ -C ₁₀ are mainly used in the tobacco industry, in the production of detergents, as well as in the manufacture of plasticizers. Alcohols of fractions C ₁₂ -C ₁₄ are used for the preparation of surfactants, foam stabilizers, additives for lubricating oils. Fractions C ₁₆ -C ₁₈ are used in the petrochemical industry as blowing agents and for the production of cosmetics. Currently, the main industrial methods for producing fatty alcohols is the following.

1. Hydroformylation of higher alkenes C ₉ -C ₁₈ to obtain aldehydes with a large number of carbon atoms, with their subsequent reduction to alcohols / RU 2291848, С07С 1/04, С07С 29/16, С07С 31/125, 2007 /. Among the main disadvantages it should be noted the multi-stage process and, as a consequence, the complexity of the hardware design; high energy costs for maintaining the process parameters of the hydroformylation and hydrogenation process - high pressure and temperature; the disadvantages associated with the use of the catalyst are deactivation, losses due to entrainment with the reaction mass, the need to isolate the catalyst from the reaction mixture, deposition of the metal catalyst on the walls of the reaction apparatus.

2. Oxidation of the paraffin fraction C ₁₀ -C ₁₈ with atmospheric oxygen in the presence of boric acid / Bashkirov AN, Komzolkin VV // Chem. science and industry. - 1959. - 4. - 607 /. This method of preparation also has a number of significant drawbacks, namely: low conversion of the feedstock, yield and selectivity for alcohols, low quality of the resulting alcohols due to the presence of various impurities in them, a large amount of wastewater generated during hydrolysis and repeated washing, the frequency of the process.

Currently, the most promising methods for producing VZhS are methods based on the use of more affordable raw materials, the hydrocarbon fraction C ₁₀ -C ₁₈ , an environmentally friendly oxidizing agent - hydrogen peroxide and a heterogeneous catalyst - titanium silicalite (TS-1).

The prototype of this invention is a method for producing VZhS by means of liquid-phase oxidation of a hydrocarbon fraction With ₁₀ -C ₁₈ aqueous solutions of hydrogen peroxide on a heterogeneous catalyst - titanium silicalite in the presence of a polar solvent / US 5021607, C07C 45/28, 1991 / at a temperature of 50-100 ° FROM.

A significant drawback of the described method is that the oxidation reaction is carried out at an elevated temperature, which leads to a decrease in the yield of higher fatty alcohols (12%) and to a deterioration in the quality of VZhS (the content of by-products increases). In addition, there is no stage of isolation of a commercial product - VZhS.

The task of the invention is to develop effective technologies for the synthesis and isolation of VZhS.

The technical result from the use of the invention is to reduce costs by reducing the temperature at the synthesis stage and increasing the yield of VZhS.

The technical result is achieved by the fact that in the proposed method for producing higher fatty alcohols (VZhS), including the interaction of the hydrocarbon fraction C ₁₀ -C ₁₈ with hydrogen peroxide in the presence of a solvent, the process is carried out at 20-50 ° C, with a molar ratio of the hydrocarbon fraction C ₁₀ - ₁₈ c and hydrogen peroxide (1.0-13.0) 1, a catalyst - a titanium-containing zeolite with MFI topology, MEL or β-zeolite having a titanium content from 0.1 to 9.5%, in an amount of 0.1 to 70 g / l of the reaction mixture, after which synthesis steps are subjected to atmospheric distillation for I remove the solvent and vacuum rectification - to remove the unreacted C ₁₀ -C ₁₈ hydrocarbon fraction returned to the synthesis step in the form of distillate and commercial higher fatty alcohols.

The synthesis and isolation of VZhS is carried out according to the following procedure: the required amount of the hydrocarbon fraction and the titanium-containing zeolite, solvent is loaded into the reactor, the magnetic stirrer is turned on, and thermostated to a predetermined temperature. After loading hydrogen peroxide, the start time of the experiment is recorded. At the end of the experiment, the content of VZhS in the reaction mass is determined by gas-liquid chromatography. The process of isolation of VZhS is carried out as follows. After completion of the oxidation reaction, the reaction mixture is subjected to separation. To this end, by distillation from the reaction mass, the solvent is distilled off, while a solution of the VZhS in the hydrocarbon fraction is removed from the cube. Obtained in the cube of the column, the solution of VZhS in the hydrocarbon fraction is sent to a vacuum column. In the distillate, a hydrocarbon fraction is sent to the synthesis stage, and commodity VZhS are taken from the cube of the column.

In the present invention, it is proposed to use a hydrocarbon fraction obtained by extractive extraction of oil fractions with carbamide and purified from higher boiling components as a raw material. The average composition of the hydrocarbon fraction is C ₁₀ -C ₁₈ : C ₁₀ -20%, C ₁₁ -30%, C ₁₂ -25%, C ₁₃ -5%, C ₁₅ -5%, C ₁₆ -5%, C ₁₇ -5 %, C ₁₈ -5%.

The invention is illustrated by examples of the process.

EXAMPLE

3 ml of the C ₁₀ -C ₁₈ hydrocarbon fraction of the following composition are charged into the reactor: C ₁₀ -20%, C ₁₁ -30%, C ₁₂ -25%, C ₁₃ -5%, C ₁₅ -5%, C ₁₆ -5% , With ₁₈ -5%, and 2.5 g of a titanium-containing zeolite with topology MF1, 36 ml of methanol solvent, include a magnetic stirrer and thermostat to 40 ° C. After loading 1.6 ml of a 35% hydrogen peroxide solution, the start time of the experiment is recorded. At the end of the experiment, the content of the VZhS in the reaction mass is determined by gas-liquid chromatography (2.2,%, VZhS). After the completion of the oxidation reaction, the reaction mixture is subjected to separation. To this end, through distillation from the reaction mass, the solvent methanol is distilled off in a column with an efficiency of 10 theoretical plates and with a reflux ratio of 5, while a solution of the VZhS in the hydrocarbon fraction (45% VZhS) is removed from the cube. The solution of VZhS obtained in a cube of a column in a hydrocarbon fraction is sent to a vacuum column with an efficiency of 5 theoretical plates and with a reflux ratio of 5. In the distillate, a hydrocarbon fraction is sent to the synthesis stage, and commodity VZhs of the following composition are taken from the cube of the column: C ₁₀ alcohols - 17.05%, C ₁₁ -29.94%, C ₁₂ -34.74%, C ₁₃ -7.51%, C ₁₅ -7.51%, C ₁₆ -3.95%, C ₁₇ -2, 73%, C ₁₈ -1.89%.

The table shows examples of the process with various combinations of process parameters, the values of which are the hallmarks of the invention.

The table shows that the optimum temperature is 50 ° C, which provides the maximum yield of VZhS, when the temperature rises above 50 ° C, the output of VZhS decreases, and at a temperature below 20 ° C the reaction rate is significantly reduced. With an increase in the molar ratio of hydrocarbon-hydrogen peroxide from 1: 1 to 13: 1 g / l with an increase in the concentration of the catalyst, an increase in the yield of VZhS is observed. With an increase in catalyst concentration of more than 70 g / l, an increase in the yield of MEK does not occur. The addition of a catalyst in an amount less than 0.1 g / l practically does not catalyze the oxidation reaction. The use of titanium-containing zeolites with different topologies of MF1, MEL or β-zeolite with an equal titanium content show the same outputs of VZhS. The use of titanium-containing zeolites with a titanium content of less than 0.1% does not show catalytic activity, with a content of more than 9.5% does not show an increase in catalytic activity.

The use of this invention can effectively and reliably solve the problem of organizing large-capacity industrial production of VZhS. The specified production is characterized by high technical and economic indicators, determined by such factors as the absence of by-products, the absence of auxiliary solvents, the absence of elevated pressures and temperatures, and the production is highly environmentally friendly.

Table Example No. one 2 3 four 5 6 Proto-
type of Temperature ° C 40 40 40 40 twenty 40 one hundred Hydrocarbon fraction From ₁₀ From ₁₀ From ₁₀ From ₁₀ From ₁₀ From ₁₀ From ₁₀ Solvent Meta-
zero Meta-
zero Meta-
zero Meta-
zero Meta-
zero Meta
zero Acetone The molar ratio of hydrocarbon: hydrogen peroxide 0.50 13.00 1.00 1.00 1.00 1.00 0.5 The concentration of catalyst, g / l 25.36 24.62 24.76 44.64 25.36 0.10 16.39 The concentration of H ₂ O ₂ , wt.% 31.2 31.2 31.2 31.2 31.2 31.2 30.0 The output of VZhS, wt.% 6.4 16.9 30.1 30.0 6.38 0.1 12.0 The degree of extraction of VZhS from the reaction mass,% 99.5 99.6 99.6 99.6 99.6 99.6 -

Claims (2)

1. The method of producing higher fatty alcohols (VZhS), including the interaction of the hydrocarbon fraction With ₁₀ -C ₁₈ with hydrogen peroxide in the presence of a solvent, characterized in that the process is carried out at 20-50 ° C, with a molar ratio of the hydrocarbon fraction With ₁₀ -C ₁₈ and hydrogen peroxide (1.0-13.0): 1, on the catalyst - a titanium-containing zeolite loaded in an amount of from 0.1 to 70 g / l of the reaction mixture, which after the synthesis step is subjected to atmospheric distillation to remove the solvent and vacuum distillation for branches returned to the stage synthesis of unreacted hydrocarbon fraction C ₁₀ -C ₁₈ in the form of distillate and commercial higher fatty alcohols. 2. The method of producing higher fatty alcohols according to claim 1, characterized in that they use a titanium-containing zeolite with the topology of MFI, MEL or β-zeolite with a titanium content of from 0.1 to 9.5%.