DE1919593A1 - Process for the production of alcohols - Google Patents

Description

Process for the production of alcohols

The invention relates to a process for the production of alcohols. In particular, the invention relates to a improved process for the production of alcohols by Oxydation.in liquid phase of aliphatic saturated Hydrocarbons with a gas containing molecular oxygen. in the presence of a boron compound as a catalyst, in the case of alcohols of high purity, that of! discoloration or obtrusive smells, due to impurities are due, are free, are to be received.

It is known to produce alcohols by oxidation in the liquid phase of aliphatic saturated hydrocarbons with a molecular oxygen-containing gas in the presence of a boron compound as a catalyst, for example Boric acid, boric acid, anhydrous. Boric acid or to produce boric acid esters. These alcohols are, for example, after an ethoxylation and / or sulfati « used as surfactants. In the The above reaction are through the boron compound obtained alcohols converted into their boric acid ester, whereby they are stabilized «The purpose of the presence of the boron compounds is therefore to prevent them of the alcohols before a subsequent oxidation and in the

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Facilitating the removal of unreacted hydrocarbons from the reaction products. Distillation.

In Mg. 1 a simplified flow diagram of the usual process is reproduced. The following describes the usual process with reference to FIG. 1. Aliphatically saturated hydrocarbons are subjected to oxidation in the liquid phase with a gas containing molecular oxygen in the presence of a boron compound. The oscillation mixture obtained is separated into unreacted hydrocarbons and boric acid esters of the alcohols by distillation. Hydrocarbons are set after the removal of such compounds as carboxylic acids, carboxylic acid esters! and lactones by saponification, for example with HatriuM-hydrosyd vmü anscfeLLieaeemasr Wäs © a @. old "Wasser zurtiolqg © -" .. ■ won. The recovered wasted hydrocarbon® vrsx-deiL to the 0x2fdi & ti © ns.Terfahr © n sri £ ^ i8kg © füM3rtv "-" .- .. "On the other hand, the dureil distillation are separated-boric acid eggs are hydrolysed, g . © gained "DI® obtained crude alcohols are washed rait water and fractionally distilled _r so'daßdie cleaned Alkohol® be obtained ■ ■■ -....;

The "alcohol" obtained in this process. are " colored unä white © ixiaa

- Problems regarding the quality b @ l

ks results * 1® were ready v «rs © lii © i © a® Tü ^ fatesa star. Hfinigmsg of the all-sofa stoves obtained in this way - " ^:

or 90-98 A 9 / U88

In the context of the present invention were now the causes of such discoloration and intrusive Odors have been studied and extensive experiments have been carried out with a view to producing alcohols that are free of coloring and obtrusive smells, which are surüokeufuhren on impurities. These investigations performed on the present invention.

Me by oxidation of aliphatic saturated hydrocarbons with a containing molecular oxygen Reaction products obtained in the presence of a boron compound in gas mainly consist of boric acid esters the desired alcohols and unreacted ones Hydrocarbons. They also contain the products impurities formed during the oxidation reaction, for example carbonic compounds, carboxylic acids, carboxylic acid esters, Lactones and unsaturated® compounds. Despite the fact that the oily impurities are practically complete directly or indirectly in the subsequent stages the recovery of the uncooked Kohi @ Ewa @@ ®? etoffe and the desired alcohols are removed, are those obtained Alcohols discolour yellow and have intrusive smells that can be attributed to contamination can. Aue of this fact it is therefore deduced that the impurities that cause the discoloration and obtrusive smells, even at the extraction stages are formed.

It has now been found that during the stage of recovery of the hydrocarbons that are not regulated Distillation of the oxidation products, some of the impurities in the products due to the distillation of the

will

Products decomposed at high temperatures ^ that these impurities and their decomposition products Towards

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decomposition of some of the boric acid esters Alcohols act and olefins and other substances give rise and cause the discoloration and obtrusive Represent odors, and that the newly formed impurities up to the end of the extraction stages cannot be removed

Se has now been found, «la®, if the VertHmsinigra« » genes in the products before the recovery of the niohtumg © » set hydrocarbons from the oxidation products removed by distillation, the desired alcohols do not contain any decomposed impurities and the like free iron discoloration and intrusive odors are.

Specifically, erfindungsgeiaäß di @ Oxydationsreaktionsprodukte are hydrolyzed immediately £ sur removal of boric acid, without being separated by distillation in nichtumgesetste hydrocarbon and alcohols, and anechliesB®M the hydroIyeierten products vers © _e Dureh ift the "a sohliessend" washing with water the removal of such impurities as Garfeoneauran, Certoonsätsr © «« esters and lactones is brought about. Then, i @ r & i? Tlgs compounds, such as anhydrous boric acid, changed! © rsäursn or borelic acid ester to the ulsohioht, which h% uptsä @ lü, i @ k vnu from non-reacted hydrocarbons . Alkohol® ^ is added and the hydrocarbons uemisoh esterified · DI® n ± Qhtiw.g® * ° will be translated again to remove then by distillation zurüokgewosxnen · The Boreäureester obtained d @ r alcohols of boric acid hy & roli "! © s"! _O Then the oil is distilled and alcohols of high purity are obtained, which are free of tone colorations and obtrusive smells that can be attributed to & t% impurities «

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In Pig. 2 shows the method according to the invention in a sohematic manner. The process according to the invention is described in detail below with reference to FIG. 2: An aliphatic saturated hydrocarbon is subjected to oxidation in the liquid phase with a gas containing molecular oxygen in the presence of a boron compound. The reaction products are hydrolyzed with water in sufficient quantities to decompose the boric acid esters of the alcohols formed. The hydrolysis is usually carried out at a temperature in the region of τοη 100 ⁰ C, but can also be carried out depending on the ease of hydrolysis of the boric acid esters of the alcohols at lower temperatures or at higher temperatures and elevated pressures. After the hydrolysis, the free boric acid is separated off and removed in a countercurrent extraction process or by a suitable number of water washes.

After the boric acids have been removed, the reaction mixture, which consists mainly of alcohols and unreacted hydrocarbons, is saponified with an alkali and then washed with water to remove the carboxylic acids, carboxylic acid esters and lactones which occur as impurities. The hydrolysis is usually carried out at 100 to 200 ⁰ C and at Atmosphärendruek or elevated pressure, but könnfln depending on the ease of saponification of the saponified material to other suitable temperatures and pressures are applied. Sodium hydroxide, potassium hydroxide and other alkalis are listed as alkali that can be used for saponification, but the use of sodium hydroxide is economically the most advantageous

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or a blessing stream extraction process can be carried out * the and the amount or concentration of the alkali used and the number of brewing and washing operations can be chosen in a suitable way * um der- = to remove similar fatty acids as far as possible.

The boric acids and the impurities occurring as by-products are removed as far as possible by the above process and alcohols, which is then heated and thereby the alcohols are converted into the corresponding boric acid esters in the ulechioht. Subsequent distillation of the oil layer, the niohtumgesatzten hydrocarbons are separated · § © 'wishes if the niehtumg © be translated hydrocarbons to the oxidation without further treatment returned · The amount of boron compound used for the esterification of alcohols MUB be sufficient to allow the alcohols completely as boric acid ester in the Stuf © exist where the unconverted hydrocarbons are removed by distillation after the conversion of alcohols to the corresponding boric · made, it is sufficient to use a sufficient amount so that the alcohols as m-Borsäureeste? · The conversion of the alcohols into the corresponding boric acid esters can usually be carried out at a temperature of 100 to 150Έ for a period of 0.5 to 3 hours, although the time and temperature can vary depending on the alcohols desired as end products. It is also preferred to carry out the "conversion of alcohols into the boric acid esters" in an inert gas atmosphere, for example nitrogen.

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SSIT can be abbreviated when "is engewandt in the azeotrope with a suitable inert solvent or an inert gas _f as nitrogen" is total passes "or by a treatment under reduced pressure, whereby the water formed by the esterification or the alcohols duroh Esterauetauseh formed in the free state can be removed from the system with good effectiveness. If it is possible to apply such conditions that a complete pouring of the alcohol into boric acid ester takes place without distilling off the alcohols used, but with distilling off unconverted hydrocarbons, it is not necessary to carry out a separate step for converting the alcohol into the corresponding BSi-sä 'to apply it'

Then the boric acid esters become? Alcohol © uat-sr suitable conditions alt @ hydrolysed in @ r suitable amount of water and thereby di®! © soätir® separated and removed and the oil layer gmmimnn ^ The äa'b®i obtained oil consists of a @ ®ais @ h ¥ © a monohydric alcohols and smaller alcohols, equivalent alcohols. The τοη discoloration and öer-üehtn fr @ i @ n alcohols can be obtained by distilling the oil layer directly or after applying a simple treatment.

There are no stages in the Seei process according to the invention sur treatment of the most non-settled hydrocarbons surüek obtained, no stage eur treatment of the obtained Alcohols and no stage but renewed distillation necessary, which is the case with the conventional process known up to now are essential. Furthermore, in the case of the invention Process and mechanical losses of hydrocarbons and alcohols that occur in these stages are avoided. You quality of surüok extracted hydrocarbons

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substances is better than with the usual process and the alcohol yields are also improved. Those contained in the finished alcohols obtained according to the invention Impurities are less than in the purified alcohols obtained by the usual methods. The quality of the product according to the invention is good and the product is technically very advantageous.

The method according to the invention is based on the production of alcohols by oxidation in the liquid phase of aliphatic saturated hydrocarbons with about 10 to 20 carbon atoms applicable to a grass containing molecular oxygen in the presence of boron compounds. Various boron compounds can be used as catalysts for the oxidation of hydrocarbons or as esterification agents for converting the alcohols into the corresponding Boric acid esters can be used. Some examples are o-boric acid, m-boric acid, dihydrotetraboric acid, dihydrohexaboric acid, dihydrodeoaboric acid, boric acid and boric acid esters. If these boron compounds are used as oxidation catalysts, an ammoniacal base can hereby be used as a promoter

The process according to the invention is further illustrated by the following examples, without the invention being limited thereby. The following examples are Alcohol «, which were obtained by the oxidation of hydrocarbons with 12 to 14 carbon atoms. The reason for this is that these alcohols have only a small proportion of the monohydric alcohols, however sharp · obtrusive smells result, even if only a small · amount «of impurities is present ·

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example

A reaction vessel was charged with 1000 g of a mixed η-paraffin having an average molecular weight of 185 and having 12 to H carbon atoms, and 28 g of anhydrous boric acid having a purity of 98.5 # was added. A gas mixture of 5 pounds of oxygen, 95 pounds of nitrogen and 100 ppm of ammonia was introduced in an amount of 10 1 per minute and the reaction was carried out for 2 hours at 175 ⁰ O The mixture was kept stirring at 100-105 ¹¹ C for 1 hour. Subsequently, the water layer was separated off and washed again once with the same amount of water and the water layer was separated off. The oily layer obtained was analyzed and it was found that the product had an acid number of 2.2, a saponification number of 8.2 and a hydroxyl number of 67.0 »

An aqueous 4 # strength sodium hydroxide solution corresponding to one third of the oily layer was added to 100 parts of the oily layer obtained, and the mixture was kept at a temperature of 100 to 105 ^° C. for 1.5 hours with stirring. The water layer was separated off and the residue washed twice with the same amount of water. 5.3 parts of boric acid was added to the oil bath, and the mixture was stirred. While introducing nitrogen, the mixture for 1 hour at the temperature of I40 to 150 ⁰ C. The unreacted paraffin distilled off during this period was returned to a stirred vessel and the water was separated off. The treated liquid was then transferred to a distillation plant

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transferred and distilled until a pressure of 5 mm Hg and a distillation temperature of 200 ⁰ C were reached, whereby the unreacted paraffin was completely removed. 1.5 times the amount of water was added to the boric acid ester of the alcohol remaining in the distillation unit and the mixture was ^{kept at the temperature of 100 °} C. for 1 hour with stirring. The mixture was then washed once with the same amount of water. The obtained oil layer was analyzed by chemical analysis, infrared spectrum or gas chromatography and contained monohydric alcohols having 12 to 14 carbon atoms as main products, minor amounts of polyhydric alcohols and traces of unreacted n-faraffins and carbonyl compounds.

The oil layer was transferred to a distillation unit and fractionated at a pressure of 5 ma Hg Using a packed column corresponding to 8 theoretical booths distilled «The first fraction consisted of small amounts of unreacted monohydric alcohols. η-Paraffin and Carbony! compounds. The second fraction consisted of monohydric alcohols and traces of carbonyl compounds. The third faction consisted mainly of dihydric alcohols and the residue consisted of a mixture of polyhydric alcohols and Hara-like high-boiling materials. The results of the analysis are in Table I summarized.

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Table I.

Distillation·-. Distillation - hydroxyl temperature ( ⁰ C) yield number (5 IMHf) (wt .- *)

Carbo- iodine- 7ernylsahl number holds-

nis des
not UBh set
Paraffins
(wt .- *)

Degree of hardening number de

Geruohe

O 1. fraction 95 - 120 2 ,1 CO
CSO 2. fraction 120 ~ 155 78 , 3 .C--
CD 3. fraction 155 - 172 14th , 7 RUoketand 4th • 9 OO
OO

228 279

436 2.5 6.8 0.6 1.6

8.2 10.1

20th 0.0

0.0 0.0

10

veniger al 5

30th

cn co co

The results of the analysis of the unreacted η-paraffin recovered by distillation are given in Table II brought

Table II Hydroxyl number 0.0 Acid number 0.0 Saponification number 0.0 Carbonyl number 8.5 Iodine number 0.2

The determination of the degree of the odor was carried out by five experts with such odor! Application of mixtures of a raw alcohol that is used in the production stage was obtained according to the usual method, and a roll-continuously cleaned odor-free n-tridecane in the proportions given in Table III as standard samples carried out

Table III

proportion of (Oew.-Jt)

Degree of smell

0 1

Raw alcohol according to the usual process

0 2 5

15 100

even more intrusive Rumor

purified · n-tridecane

100 98 95 85

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The odor was compared in the same way in the following comparative examples.

Comparison example 1

The oxidation product obtained using the same starting materials and under the same conditions as in the previous example was immediately subjected to a simple distillation at a pressure of 5% Hg and a temperature of 200 ° C to remove the most unsettled η-paraffin the boric acid esters obtained as a residue of the alcohols was sugesetst 1,5-faohe amount of water and stirring the mixture for 1 hour at 100 to 105 ⁰ C was maintained · AnschiIeβsend the Wassersohloht was separated and again washed 1 time with the same amount of water. The water layer was separated

To 100 parts of the oil layer obtained were 40 Parts of a 1Obigen aqueous solution of sodium hydroxide added and the mixture was kept at a temperature of 100 to 105 ° C. for 1.5 hours while stirring. The water layer was then removed and washed 2 times with the same amount of water · The The oil layer obtained was fractionated under a τβτ-reduced pressure τοη 5 mm Hg using the smooth Apparatus as in the previous example, distilled The results are summarized in Table IV.

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Table IY

Dtβtillation · - Distillation- hydroxyl- carbonyl- iodine- ratio- rabbit- degree temperature ( ⁰ C) yield sahl sahl saw! never de * sahl dee (5 na Hf) (Gew, -Ji) nlchtum- Ge

(eeetxten ruohs

Paraffins

(Wt .- *)

CD 1. fraction 95 - 120 4th .2 174 8th ,8th 8th t5 31 2 200 5 ο 2. fraction 120 - 155 77 , 3 271 4th .6 2 ♦ 3 0, 0 160 4th CD
CO 3. fraction 155 - 172 9 , 2 383 8th • 7 9 , 2 0, 0 350 5 CD Residue 9 , 3 0, CO co

CD Ca)

The results of the analysis by distillation Surüok obtained non-cumulative η-paraffins are in Table T below

Table T

Hydroxyliahl 1.7 Acid number 2.2 Saponifying steel 9.3 Carbonyl steel 12.8 Iodine meal 1.2 Ter ^ lelohsbeisplel 2

The large fraction obtained in Comparative Example 1 was again distilled at 5 Hg using the same device as in Comparative Example 1. The results obtained are shown in Table VI:

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Table VI

Distillation · - Deetil- hydroxyl- carbonyl- iodine- ratio rabbit- degree temperature ( ⁹ C) lation- Kahl number de «niohtua- number of the (5 mm Hg) yield set set

(Ge w, -Jt) Paraffins ruohs

(Wt .- *)

1st parliamentary group

Main faction

Residue

less than 120

120-155

96.1 2.1

248

276

6.4 3.8

3.0 2.2

180

120

Claims (2)

Claim HV process sur production τοη alcohols by Oxidation in the liquid phase τοη aliphatic saturated hydrocarbons bit 10 to 20 carbon atoms with a molecular oxygen containing Gas in the presence of a boron compound, characterized in that the oxidation products are hydrolyzed and the boric acid obtained is removed »the products obtained thereby are saponified and washed with water, a boron compound su the obtained, mainly from alcohols and unreacted hydrocarbons The existing oil layer is added and the alcohols contained in the oil layer are converted into the corresponding boric acid esters, the oil layer being separated the unreacted hydrocarbons are distilled, the boric acid esters are hydrolyzed and the boric acid obtained is removed and the oil obtained under Obtaining the alcohols is distilled. 2. The method according to claim 1, characterized gekennseiohnet that the boron compound o-Borstture, a-boric acid, Dihydrotetraboric acid, DlhydrQhexaboric acid, Dihydrodecaboric acid, boron oxide or boric acid ester can be used. 9098A9 / U88