US2055095A

US2055095A - Recovery of organic acids from oxidation products of hydrocarbons

Info

Publication number: US2055095A
Application number: US756702A
Authority: US
Inventors: Beller Hans; Schellmann Max
Original assignee: IG Farbenindustrie AG
Current assignee: IG Farbenindustrie AG
Priority date: 1933-11-07
Filing date: 1934-12-08
Publication date: 1936-09-22
Anticipated expiration: 1953-09-22

Description

Patented Sept. 22, 1936 i 2,055.09; necovuar or one amc sums anon! on DATION raonuc'rs or nvnaocaanons Hans Beller, Ludwigshaien-on-the-Rhine, and

Max Schellmann, Mannheim, Germany, as-

' 2,055,095 FFlC'E signors to I. G. F'arbenindustrie Aktiengesell-- schatt, Frankfort-on-the-Main, Germany No Drawing. "Application December 12,1934, Serial No. 156,702. In- Germ'any November 7,

- '11 Claims.

I'he present'invention relates to improvements in the recovery of organic acids irom oxidation products of liquid or solid, non-aromatic hydrocarbons, such as scale wax, purifledparaflin wax, paraihn oils, or crackedfractions of petrolatum. In Patent No. 1,931,859, dated October 24th,

c 1933, one of us has described a process for the recovery of organic acids form the oxidation prod-- nets of non-aromatic hydrocarbons, which is based on thesaponification of the oxidation products with aqueous solutions of carbonates of the alkali metals 'or alkaline earth metals. It has also been proposed to saponiiy the oxidation products of non-aromatic hydrocarbons with oxides or hydroxides of the alkali metals or alkaline earth metals in order to recover the acid components.

As is known, the oxidation with air or other agentsiyieldixk oxygen, such as nitrogen oxides in the liquid or gaseous phase, yields besides the valuable normal carboxylic acids also hydroxy carboxylic acids or derivatives thereof, such as lactones, lactides, estolides, etc., which compounds we may designate as super-oxidized components of the oxidation products; they injure considerably the duality. of the oxidation products.

By means 01! the known saponification methods; these undesirable super-oxidized components 80 are obtained together with the carboxylic acids and can be removed therefrom only in a costly and complicated manner. The "presence of these components can be recognized by the fact that,"

the carbdxylic acids are not completely soluble 5 in low-boiling hydrocarbons on account of the;

. presence, for'instance, of hydroxy acids, and that the acid-and saponiflcation numbers of the acid parts which havebeen completely freed from unsaponifiable components, show a substantialdii- 40 ierence which is usually designated as ester number. i Typical carboxylic acidsas obtainable, ior in: stance, by the oxidation of crude scale wax with air in the liquid phase, show an ester num ber oi about 30 to '70 and a content of acids insoluble in low-boiling hydrocarbons, for instance, petrol ether, of about 5 t o-15 percent; these acids are hydroxy fatty acids. I

We have ow found that fatty acids tree or practidally i ee from the said undesired component such as hydrozw acids can be obtained from. t e oxidation products of from liquidto solid, non-aromatic i, e. open chain aliphatic or cycloaliphatic hydrocarbons by removing the water during the saponiflcation which is-carried out with alkaline reacting agents such as, for

instance oxides, hydroxides, or carbonates of alkalior alkalin'e earth metals. Thus duringthe whole ,saponi'flcation period orat least a substaniftial part thereof, practically no water is prme'nt.

(01. 260-122) I a I The reaction can be commenced in the presence of water, but on reaching higher temperatures,

, great care must be taken that all the water, that is, the water which may have been used for dissolving or dispersing the alkaline reacting agent, 5 and the water formed during the saponiflcation reaction, is removed. Suitable temperatures e those of about 150 C. to about 300 C. For practical reasons one will work at about 280 to 300 0., whereby the reaction is usually. finished in 10 about 1 to 2 hours.

' The presence of inert'gases' doesnot disturbthe reaction; it may even be advantageous, yielding lightly colored products. Also, additions can bemade which favor the splitting of! of water or yield-especially lightly colored products such as,

for instance, aluminum oxide or metal powders of, tor instance, zinc, copper, magnesium or aluminium. I

While it is possible to work under ordinary pressure, reduced pressure may be applied where- L by the removal of water from the highly heated soap is favored. On the other hand it may be of advantage to effect thesaponification under increased pressure. The unsaponiflable parts I present during the saponiflcation 01' the saponi fiable parts act presumably as solvents or diluent's for the latter andthereby help to avoid -undesired cracking of the soaps at the high temperatures applied.- Unsaponiflable matter from an external-smirce may be added to the material to be saponifled iory the same purpose.

The saponiflcation can be carried out, for instance, with caustic alkalies, alkali carbonates, oxideslor hydroxides otthe alkaline earth metals or with mixtures of these alkaline reacting a'gentswhich may be employed in dry form or in aqueous solution or suspension, whereby gen-' erally an excess of about 3 to 8 per cent over the .amount or saponifying agent, theoretically required, is applied; the theoretical amount isto correspond tothe saponiflcation number otthe respective oxidation product. .It may, however,

\ be advantageous to employ lower amounts of the alkaline reacting reagents than the theoretical amount, for example per cent oi the latter.

Suitably, the reaction is carried throughina closed and heatable vessel provided with a stirrer, from which vessel the water vapor produced during the reaction, partly by'the saponiiilcation reaction at to 200? C.', and partly by the splitting oi! or '.water from hydroxy acids or derivatives thereof at 180 to 350 0., is 6ontinuously released. .j'l'he hydronacids are by c this treatment, practically almost completely, trapsior'med into other products, and the ester number of the oxidation product is, substantially diminished or evendisappears completely. In stead of continuously releasing the pressure it may be released from time to time.

If free acids are to be produced the saponification mixture is acidified and the acids are recovered. Otherwise the acids are obtained in the form of their salts.

The following table shows the results which were obtained in the saponification of the oxidation product of crude scale wax at low temperature in the presence of water, at high temperature in the presence of water and under pressure, and at high temperature in the absence of water.- These results show clearly that the effect arrived at by saponification at a high temperature in the presence of water is considerably improved by working in the absence of water.

especially desirable.

The following examples will further illustrate the nature of the present invention but the invention is not restricted to these examples. The

parts are by weight.

Example 1 An oxidation product, obtained by oxidation of crude scale wax with air at 140 C. in the liquid phase and containing 44 per cent of unsaponifiable components, is washed with water for the removal of water-soluble acids, and thereupon saponified in an autoclave provided with' astirrer, with an amount of anhydrous caustic soda by 4 per cent. in excess of the amount required for the'complete saponification of the fatty acids and esters, for four hours and at-frocm 290 to 300 C. After a temperature of 150 C. had been reached, the water produced by the sapo'nification reaction is removed by releasing, the pressure each time when the pressure in the autoclave had risen to about 10 atmospheres. The reaction is brought to a finish without the application of super-atmospheric pressure.

After cooling, the reaction mass is mixed with water and the unsaponifiable parts are removed by extraction with low-boiling hydrocarbons, and from the aqueous solution of the soaps the fatty acids are liberated by acidification with diluted sulphuric acid. After washing with water,

these acids show the following analytical data:

Acid number .190

Saponification number 199 Ester number 9 Per cent hydroxy acids-.. 0.9

Example 2 An oxidation product from purified scale wax I containing 59 per cent of unsaponifiable components and obtained by oxidation with air at 140 C., in the presence of a manganese catalyst, is saponified withdry sodium carbonate in excess, at290-300 C. in an autoclave provided with a stirrer, the pressure produced being released in the same manner as in Example 1.

The reaction is brought to a finish in the absence of water and without the application of superatmospheric pressure.

On application of the working-up method described in Example 1, fatty acids are obtained from the reaction mixture which, after distillation, show the following analytical data:

Acid number- 240 Saponification number 240 Ester number Per cent hydroxy acids 0 Example 3 The oxidation product referred to in Example 1 is mixed with a suspension of calcium hydroxide in 10 times its amount of water, calcium hydroxide being employed in an excess of 7.5 per 1 cent of the amount theoretically necessary for the complete saponification of the fatty acids and esters. The mixture is treated for 2 hours in a stirring autoclave at from 290 to 300 C.

The removal of the water added and formed during the saponification is effected by releasing the pressure after the temperature of 300 C.

has been attained. The saponification is then 1 completed without the application of superatmospheric pressure. The saponification product obtained is mechanically disintegrated and heated to boiling with an excess of an aqueous sodium carbonate solution until the calcium soaps are converted into sodium soaps. After filtering oif the calcium carbonate precipitated,

the filtrate is worked up in the manner described in Example 1. The crude fatty acid mixture thus obtained has the following characteristics:- Acid number 187 Saponiflcation number 200 Ester number 13 Per cent hydroxy acids 2.4

This mixture is subjected to a steam-distillation under a pressure of from 10 to -15 millimeters mercury gauge with a maximum temperature of 280 C. The fatty acids thus obtained have the following characteristics:

Acid number 23-6 Saponification number 239 Ester number 3 Per cent hydroxy acids 0 The color of the product determined in the 6"-cell of the Lovibond-tintometer (compare Holde, Kohlenwasserstoffe, 61c und Frette 7th edition, 1933, pages 233 to 234) is yellow 40 and red-12. 4

Example 4 The oxidation product referred to in Example 1 is saponified with barium hydroxide (Ba (OH) 2.H20)

under otherwise the same conditions as indicated in Example 3. After the steam-distillation in vacuo a fatty acid mixture is obtained which has.

the following characteristics:

Acid number I 209 Saponification number 211 Ester number -1 e 2 Per cent hydroxy acids 0 Color (determined as indicated in Example 3) yellow 35 and red 1'7.

Example 5 The oxidation product referred to in Example 2 is treated with anhydrous sodium carbonate (85 per cent of the amount theoretically nec usary for the complete saponinca'tion of the fatty acids and esters) for 2 hours at about 300 C. in a stirring autoclave, the water formed in the sa-' 5 poniflcation being removed from the reaction mixture by temporarily releasing the pressure after a temperature of 300 C. has been attained; After working up as described in Example 1 a crude fatty acid mixture is obtained whichha the following characteristics:

Acid number 19'! Saponiflcation number 209 Ester number 12 15 Per cent hydroxy acids l 1.9

After steam-distilling the product under the conditions stated in Example 3 a fatty acid mixture is obtained having the following character istics:

Acid number k i 226 Saponification number 228 Ester I number 2 Per cent hydroxy acids 0 Color (determined as indicated in Example yellow 42 and red 7.5.

EzamDleG t The oxidation product referred to Example 2 is treated for 2 hours at 300 0. with a -20 icent aqueous solution of sodium carbonate which is employed in a 10 per cent excess of the" amount theoretically necessary for completely saponifylng 5 the fatty acids and esters. The saponincation is carried out under a pressure of from .25 to 40 v millimeters mercury gauge in a vessel provided with a stirrer and a reflux-condenser which is heated with ,steam; The-'non-saponiflable compounds boiling above 100 C. are thus condensed 40 and flow back into the reaction vessel while the water added and formed in .thereaction distils off through the reflux condenser and is collected ina cooled receptacle. y After working up as described in Example .1

a mixture of fatty acids is obtained which after t steam-distillation under the conditions of Example 3 has the following properties; Acid number I Ester number k i 0 Per cent hydroxy acids 0 Color (determined as indicated in Example 3) yellow 30 and red 14. j t v 100 parts or the oxidation preduttre'zerred'te. in Example 1 are treatedwith anhydrous carbonate (10 per cent excess of the amounttheoreticallynecessary for thecompletesarioniflcation of the fatty acidsand esters) with the addition of parts*of crude paraffin wax at about 300 C. fori2 hours in a stirring autoclave. As

soon as the temperature of 300 G isattained the waterformed inthe saponiilcation is removed -byrelease of the pressure and thesaponiflcation is completed under ordinary pressure;

" The crude fatty acid mixture obtained by working up in the manner described in Example .1 i

70 has the following characteristics:

Acid number e 193 "Saponification number 204 t Ester number 11 16 Per cent hydroxy acids;

' working up as vi'ollt'uiviuiz characteristics: t

v m 50 Saponification number 223' The fatty acids obtained in} steam-distillation in vacuo of the said crude mixture have the following properties: v

Acid number: 228 Saponiilcation number 228 Ester number 0 Percent hydroxy acids 0 Color-- (determined as yellow 24 :and red 16.

i Example 8 500 parts 8f the oxidation product referred to in Example 1 are treated for 2 hours at about indicated. in Example 3) 300 C. in a stirring autoclave with an amount .of 15 following characteristics: 25 4mm number i 184 j Saponification number 199 Ester number 15 Per cent hydroxy acids 0.8 so

By subjecting the crud mixture to a steamdistillation in the vacuum as described in Example 3 fatty acids are obtained which possess the' Acid number. 245 {86 Saponification number 245 Inter-number; i 0 Per cent hydroxy acids 0 Color (determined as indicated in Example 3) i yellow and red 12.-

If'instead of the zinc dust 0.5 part of alumini-,

z um dust is employed a crude fatty acid'mixture of .the following characteristics is obtained:

Acid number i 187 t Saponiflcation number 197 i Ester number 10 Per cent hydroxy acids 1.5

1 By steam-distillation in vacuo this product yields afatty acid mixture of the following char acteristics;

Acid number; 231 S aponiflcation number 235 Ester number 4 Per cent hydroxy acids 0 Color (determined as indicated in Example 3) yellow 20 andred 10.

If instead of zinc dust 0.5 part of magnesium powder is added -a fatty acid mixture 'is obtained which "has the following characteristics:-.

Aoid number 188 8a 'tion' number 200 Ester number .,I;.. ,121 Percent hydroxy acids 1.8

After distilling the product as indicated above a fatty acid mixture of the following charac teristies is obtained. I r

'A'cid number Y 242 Saponiilcation number s 245' Ester number- Per cent hydroxy acids 0 Color (determined as indicated in Example 3) yellow 24 and red 6.5.

Example 9 500 parts of the oxidation product referred to in Example 1 are treated in a stirring autoclave for 2 hours at about 300 C. with sodium hydroxide (40 per cent excess of the amount. theoretically necessary for the complete saponification of the fatty .acids and esters) with the addition of 25 parts of titanium dioxide. The water formed is removed as described in Example 5.

By working up as indicated in Example 1 a crude fatty acid mixture is obtained having the following characteristics:

Acid number 196 Saponification number 206 Ester number 10 Per cent hydroxy acids 2.3

After distilling this mixturein the-manner in-' dicated in Example 3 a fatty acid mixture of the following characteristics is obtained.

Acid number 227 Saponiflcation number A 232 Ester number .Per cent hydroxy acids Color (determined as indicated in Example 3) yellow 40 and red 10.5.

Example 10 kept at 300 C. for 2 hours, after each 30 minutes the pressure being released and fresh hydrogen being pressed in up to a pressure of 50 atmospheresm The crude fattyacid mixture obtained after working up as described in Example 1 has the following characteristics.

Acid number 169 Saponification number 182 Ester number 13 Per cent hydroxy acids 1.7

After distilling this product as described in Example 3 a fatty acid mixture is obtained .which has the following characteristics.

Acid number- 239 Saponification number 243 Ester number. 4 Per cent hydroxy acids 0 Color (determined as indicated in Example 3) yellow 30 and red 4.5.

What we claim is:

1. A processfor recovering substantially the entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation of from liquid to solid,-non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the entire oxidation product to a saponiflcation process at temperatures of from about C.

to about 350 C. by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals while removin thewater and separating the unsaponifiable part of the oxidation product from the saponified part.

2. A process for recovering substantially the entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons, in the- 3. A process for recovering fatty acids, which comprises subjecting oxidized material comprising the saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons to a saponification process attemperatures of from about 180 C. to about 350 C. by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals, substantially in the absence of water and setting free the acids from the latter.

4. A process for recovering substantially the entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the entire oxidation product to a saponification process at temperatures of from about 180 C. to about 350 C. by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkalimetals and alkaline earth metals, while removing the water, separating the unsaponifiable part of the oxidation product from the saponifietl part and setting free the acids from the latter. i

5. A process for recovering substantially the entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidationof from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the'entire oxidation product to a saponification process at temperatures of from about 180 C. to

about-350 C. by means of an alkaline reacting agent selected from the group consisting of-the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals in an amount by about 3 to 8 per cent in excess of that corresponding 'to the saponification number of the entire oxidation product, substantially in theabsence of water, separating the unsaponifiable part of the oxidation product from the saponified part and setting free the acids from the latter.

6. A process for recovering substantially the entire saponifiable .part of an oxidation product, obtainable by the liquid-phase oxid'ation of from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the entire oxidation product in a closed, pressuretight vessel to a saponification process by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkaline metals and alkaline removed from the reaction vessel,

earth metals, substantially in the absence of water, at temperatures of from about 150 C to about 300' Ct, care being taken that any water vapor produced by the saponiflcation reaction is finishing the reaction in the absence of super-atmospheric pressure, separating the unsaponificable part of the oxidation product from the saponified part and setting free the acids from the latter.

7. A process for recovering substantially th g entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons, in

i the form of fatty acids, which comprises subjecting the entire oxidationproduct to a saponiflcation process at temperatures of from about 280 C. to about 300 C. by means of an alkaline reacting agent selected. from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals while removing the water and separating the unsaponi-- flablepart or the oxidation product from the sapon ified part.

8. A process of recovering substantially the entire saponiflable part of an oxidation product, ob-. tainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the entire oxidation product to a saponiflcation process at temperatures of from about 280 C, to about 300 C. by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals, substantially in the absence of water, separating the unsanoniflable part or the oxidation product from the saponifled part and setting tree the acids from the latter.

9. A process for comprises subjecting. oxidized material comprising the'saponiiiabl part of an oxidation product,

' obtainable by the liquid-phase oxidation of from part and setting free 7 11. A process'forrecovering substantially the.

- oxidation product,

recovering fatty acids, which liquid to solid, non-aromatic hydrocarbons to a saponification process at temperatures of. from about 280 C. to about300 'C. by meansof an alkaline reacting'agent selected from the group consisting of the oxides, hydroxides and carbonates of the ,alkali metals and alkaline earth metals, substantially in the absence of waterand setting free the acids from the latter.

10. A process for recovering substantially the entire saponifiable part of an oxidation product, obtainable by the liquid-phase oxidation or from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subiec :ing the entire oxidation product to a sapomflcatemperatures of from about 280 C. to about 300 C. by means of an alkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals, whileremoving thewater, separating the unsaponifiable part of the oxidation product from the saponifled the acids from the latter.

tion process at entire saponiflable part of an oxidation product,

obtainable by the liquid-phase oxidation of from liquid to solid, non-aromatic hydrocarbons, in the form of fatty acids, which comprises subjecting the entire oxidation product to a saponification 4 process at'temperatures ot from about 280, to ,about' 300 C. by means or annalkaline reacting agent selected from the group consisting of the oxides, hydroxides and carbonates of the alkali metals and alkaline earth metals in arflamount by about 3 to 8 percent inexcess of that correspondmg to the saponiflcation number or the entire substantially in the absence of water, separating the unsaponiflable part of the oxidation product from the saponifled part an setting-free the acids from the latter. HANS BHLER.