SU555082A1 - The method of separation of primary alcohols - Google Patents

Description

one

The invention relates to the field of production of higher fatty alcohols and is aimed at improving the method of separation of primary alcohols, which are a valuable raw material for the production of surfactants, from a mixture of them with secondary alcohols, as well as a complex mixture consisting of primary and secondary alcohols , hydrocarbons, ketones and other substances.

There is a known method for separating primary alcohols from unwashed -P and includes the following processes: distillation of neatly soluble-P into 2-4 fractions with a boiling range of 40-50 ° C; the treatment of fractions with boric acid in order to convert the alcohols contained in them into the complete esters of boric acid (trialkylborates) at 110-120 ° C under vacuum at a residual pressure of 100-150 mm Hg; distilling off hydrocarbons and other substances that react with boric acid from trialkyl borates in vacuum at a residual pressure of 5-10 mm Hg; hydrolysis of trialkylborates with water; dastall shch alcohols; boric acid regeneration. The essence of the method lies in a significant difference in the temperature of the ejection, on the one hand, of hydrocarbons, ketones and other substances contained in the fractions, and, on the other hand,

parties, full esters of primary and secondary cmipTOB, which allows to separate these products

12. :

The disadvantage of this method is the unsatisfactory quality of the alcohols produced, containing, along with primary alcohols, 30-35% secondary alcohols, 8-10% diols, 3-5% hydrocarbons, 3-5% ketospirits and ketones. Alcohols have a special odor and darken during storage. The high content of secondary alcohols and other impurities does not allow to obtain surface-active substances of good quality.

The aim of the invention is to improve the quality of C1 curls.

For this, the esterification with boric acid of oxidation products or the processing of oxidized hydrocarbons containing primary and secondary alcohols is carried out at a molar ratio of boric acid - 1: 1-2 alcohols and a temperature of 130-220 ° C. The obtained boric esters are directly heat treated at 250-320 ° C. It is desirable to conduct heat treatment with simultaneous distillation of the products of decomposed boric acid secondary alcohols.

The proposed method is based on the thermal stability of incomplete borate esters of primary and secondary software (yes and monoalkyl borates or their mixtures), as well as on the boiling point of boiling water of primary alcohol and its decomposition of decomposed xyrfluoropolyhydrate esters of primary alcohols and their decomposition of boring acidifiers. , ketones and other substances.

The indicated ratios of reagents and temperature when eryphating alcohols with boric acid allows to obtain MONO-, dialkylborates or their mixture. Compounds of alcohols and boric acid are obtained, in which 1-2 moles of alcohols are used per 1 mole of boric acid. In the known method, trialkylborates are obtained which contain 3 moles of alcohols per 1 mole of boric acid. The preparation of mono- or dialkylborates is a prerequisite for the method, since these borates of primary and BTOpiwHbix alcohols have a significantly greater difference in thermal stability than the trialkylborate of the first and secondary alcohols. The use of a higher temperature esterificage is associated with the need to reduce the duration of the reaction to Koiflta.

The essence of the preventative method is that the initial mixture, which includes primary and secondary alcohols, for example, alcohols, separated from kaomylyemye-P in a known manner, hydrogenated is not shed, unpersed-f products using cations using the rectification process should be treated with boric acid at 130–220 ° C under conditions that allow the removal of reactive water vapor to convert the alcohols to d, or monoalkylborate (or a mixture of monoalkyl borate) at a mole The ratio of boric acid / alcohol equal to 1: 2 to 1: 1. The etherification is heated and maintained at 250-320 ° C for several hours or minutes, depending on the telesheature. The heat-treated product is distilled under vacuum (residual pressure of 2–20 mm Hg), and the heat treatment and distillation steps can be combined, and the temperature of the cubed piece by the end of distillation should be 280–320 ° C. Llstyll is produced and used, for example, as a feedstock for oxidation, the distillation residue, which is monr-, dialkylborates (or mixtures thereof) of primary alcohols, is decomposed by water. The selected alcohols are distilled and used as a marketable product.

Example 1. 70 kg of commodity alcohols extracted from unwashed-P and 23.7 kg of orthoboric acid are mixed in an apparatus with a mixer for 2 hours at a temperature of 140 ° C and a residual pressure of 300-400 mm Hg. 80.9 kg of product containing monoalkylborates are obtained. The product is withdrawn for 2.5 hours at 280 ° C under vacuum (residual pressure of 10 mm Hg). About 30 kg of distillate and 50.9 kg of ostagka were emitted. Subsequently, it is hydrolyzed and washed with water, the alcohols are distilled. 37.5 kg of distilled alcohols (53.7% of the original), whose characteristics are presented in the table, will be consumed.

PRI mme R 2. kg of Cg-Cao alcohols, vydelenzhen) 1X IZ neomylaem-P of the same batch as in example 1, is mixed with 15.7 kg of orthoboric acid for 2 hours at 140 ° C in vacuum (residual pressure of 300-400 mm Hg). 70.9 kg of etherification are obtained containing 20.0% of bound boric acid, i.e. represented by a mixture of monoi dialkylborates. 62.8 kg of etherification is placed in a cube for heat treatment and distillation distillation. The duration of the combined process of therm-processing and distillation at a temperature of 280 ° C. under vacuum, the residual pressure of 5 mm Hg) is 5 hours. Received 23.7 kg of distillate. Dust is decomposed with water and washed. 40.9 kg of crude alcohols are obtained, and after distillation 39.7 kg of distilled alcohols are obtained. The yield of distilled Hbix alcohols from heat treatment of the esterification is 63.3%. The same output distilled alcohols from the original commodity alcohols. Characteristics of alcohols are given in the table.

EXAMPLE 3: 249.8 g of the fraction of unsaturated-P from example 4 (hydroxyl number 102) and 22.4 g of orthoboric acid are mixed in a flask with a hermetic stirrer, equipped with a condenser and a receiver of water, from which oil condensate return to the flask. The temperature of etherification is 230 ° C, the duration is 30 minutes. The etherification, containing a mixture of mono- (80%) and dialkylborates (20%), is heated in the same flask to 280 ° C and held at this temperature at atmospheric pressure for one hour.

The hydrocarbon vapors are condensed and returned back to the flask through a water receiver. 251.7 g of etherification and 13.5 g of water creep. The etherification was placed in a vacuum distillation flask and distilled off the distillate, with the bottom of the distillation temperature being 297 ° C, in pairs - 186 ° C with a residual pressure of 13 mm Hg. The residue is washed with water and distilled in vacuo. 59.5 g of distilled alcohols (23.9% of the neat fraction) are obtained. Their characteristics are given in the table.

Example 4. 60 g of neomyl-P fraction boiling at normal pressure and temperature 250-400 ° C, containing 35% of compounds with hydroxyl group (hydroxyl number 102), including 26.5% of primary alcohols, are mixed with 6, 7 kg of orthoboric acid in an apparatus with a stirrer at 140 ° for 2 hours with a residual pressure of 300-400 mm Hg The esterification in the amount of 60.9 kg containing monoalkylborates is placed in a distillation cube and the nocTeneifflo is heated at a residual pressure of 10 mm Hg. to 280 ° C, after which, under these conditions, 2.5 hours. 40.7 kg of distillate and 20.2 kg of residue were obtained. The residue is hydrolyzed, washed with water and distilled, the yield of the distributable alcohols is 15.1 kg (25.2% of the initial fraction — unshaven-P). Characteristics of distilled alcohols in the table. Example 5: Of the fraction neatly mA-P, boiling away at normal pressure and at a temperature of 250-400 ° C, containing 35% of compounds with a hydroxyl group (hydroxyl number 102), including 26.5% of primary alcohols, Oxyrates are supplied through trialkylborates, 249.5 g of the fraction are transferred from 9.75 g of orthoboric acid in a flask with a mist inhalant for 2 hours at a temperature of 120 ° and a residual pressure of 300-400 mm Hg. An etherification in the amount of 246 g (containing trialkylborates) is placed in a flask for vacuum distillation and at a residual pressure of 10 mm Hg. hydrocarbons are distilled off. The temperature at the end of the distillation is 213 ° C in cubes, 300 ° C in cubes. The residue is discharged, decomposed with hot water, the alcohols are washed with water and distilled. The yield of distilled alcohols is 61.5 g (24.6% of the starting fraction). Characteristics of alcohols are given in the table. The proposed method allows to obtain alcohols of significantly higher quality with a minimum amount of such impurities, such as secondary alcohols, diols, hydrocarbons, keto compounds, with the best indicators in color and smell. The resulting alcohols have a degree of conversion to alkyl sulfates 12-15% higher than the alcohols of the known method, are equivalent in quality and degree of conversion to agil sulfates to primary alcohols, produced by the method of catalytic reduction of the methyl esters of synthetic fatty acids by hydrogen, but have a much lower estimated cost than the latter . Example 6. 67 4g fraction of hydrogenate containing 30% Cio-Cjo primary alcohols and 6% C, o-C2o secondary alcohols (hydroxyl number 133) and obtained by hydrogenation on an oxidized paraffin stationary zinc chromium catalyst (fraction boiling over at 320-360 ° C ), and 89.6 g of boric acid are transferred under the conditions of Example 3. In this case, the alcohols and boric acid are converted into a mixture of mono- (90%) and dialkylborates (10%). The esterificate (69 2 g) is placed in a vacuum distillation flask and distilled off at a residual pressure of 7 mm Hg. for 50 minutes 478 g of hydrocarbons. The liquid temperature at the end of the distillation is 320 ° C. The borates remaining in the cobbe (211.3 g) are hydrolyzed and washed with water, the crude alcohols are distilled in vacuum and 189 g of distilled alcohols (28% of the initial hydrogenation fraction) are obtained. Their analysis by gas - liquid chromatography shows the content of 98% of primary alcohols. Characteristics of alcohols are given in the table.

Characterization of the fraction of neomylaem-P, absorbing up to 400 ° C (sample 1), commodity alcohols, isolated from minerals-P by a known method (sample 2), and alcohols obtained by the proposed method (samples 3-7)

Neomymyemye fractions-P

Commodity

Example 1

Example 2

Example 3

Example 4

Example 5

Claims (2)

Invention Formula A method for separating primary alcohols from the product or decomposition or non-processing of oxidized carbohydrates (B) containing dervic and secondary alcohols, by etherification of boroic acid to the heating of the NII using pprolysis obtained with this borate esters, and distant fay, about tl and h and the fact that, with the aim of improving the quality alcohols, esterification with boric acid is carried out at Mo rvdm ratio of boric acid: alcohols,  1: 1-2, temperature 130-220 ° C and obtained Boron esters immediately before hydrolysis is subjected to heat treatment at 250-320 ° C. 2. The method according to claim 1, characterized by the fact that heat treatment is carried out with simultaneous distillation of the decomposition products of the secondary alcohols boric acid. Sources of information taken into account in the examination: 1. USSR author's certificate No. 213878, M.KL. C 07 C 31/02, 1968. 2. Loktev S.M., Vysache zhirdash alcohols, M., 1970, pp. 163-178.