Process for the decarboxylative ketonization of fatty acids or fatty acid derivatives

Abstract

Process (P) for the decarboxylative ketonization of fatty acids, fatty acid derivatives or mixtures thereof in the liquid phase with metal compounds as catalyst wherein the fatty acids, fatty acid derivatives or mixtures thereof are added sequentially. Downstream chemistry can be realized starting from internal ketones obtained by process (P), especially in order to design and develop new surfactants.

Claims

1. A process P for the decarboxylative ketonization of fatty acids, fatty acid derivatives or mixtures thereof in liquid phase with metal compounds as catalysts, the process comprising: a) in a first step, elementary metal or a metal compound, said elementary metal or metal compound being selected from the group consisting of iron, iron (II) oxide, a mixed oxide of iron (II) and iron (III), magnesium and magnesium oxide, and at least one fatty acid, at least one fatty acid derivative or a mixture thereof comprising at least 10 mol %, based on the entire amount of fatty acid or fatty acid derivative, of fatty acid having 12 carbon atoms or less or derivative of fatty acid having 12 carbon atoms or less, are mixed in a molar ratio of from 1:0.8 to 1:3.5, wherein the molar ratio is of the elementary metal or metal compound to the total amount of carboxylic groups in the at least one fatty acid, at least one fatty acid derivative or a mixture thereof, and reacted for a period P.sub.1 of from 5 min to 24 h at a temperature T.sub.1 which is above 270° C. and below 300° C. in the absence of added solvent, and b) thereafter the temperature is raised to a temperature T.sub.2 which ranges from 300° C. to 400° C., and additional fatty acid, fatty acid derivative or a mixture thereof comprising at least 10 mol %, based on the entire amount of fatty acid or fatty acid derivative, of fatty acid having 12 carbon atoms or less or derivative of such fatty acid, is added over a period of time P.sub.2 of from 5 min to 24 h in the absence of added solvent until the molar ratio of the elementary metal or metal compound to the total amount of carboxylic groups in the at least one fatty acid, at least one fatty acid derivative or a mixture thereof is in the range of from 1:6 to 1:99.

2. The process in accordance with claim 1 wherein temperature T.sub.1 is from 272° C. to 298° C.

3. The process in accordance with claim 1 wherein temperature T.sub.1 is from 275° C. to 295° C. period of time P.sub.1 is from 5 min to 360 min, and period of time P.sub.2 is from 15 min to 18 h.

4. The process in accordance with claim 1 wherein temperature T.sub.2 is in the range of from 305° C. and up to 380° C.

5. The process in accordance with claim 1 wherein the difference of temperature T.sub.2-T.sub.1 ranges from 15° C. to 50° C.

6. The process in accordance with claim 1 wherein water formed during the reaction is continuously removed from the reaction mixture.

7. The process in accordance with claim 1 wherein step a) is carried out at a temperature T.sub.1 of from 280° C. to 295° C. for a duration of from 15 min to 360 min and the fatty acid, fatty acid derivative or mixture thereof in step b) is added over a period P.sub.2 of from 2 hours to 16 hours.

8. The process in accordance with claim 1 wherein, after the temperature has been raised to T.sub.2 and before the additional fatty acid, fatty acid derivative or mixture thereof is added over period of time P.sub.2, said temperature is maintained at temperature T.sub.2 during a period of time P.sub.12 of from 30 min to 300 min.

9. The process in accordance with claim 1 wherein, after the additional fatty acid, fatty acid derivative or mixture thereof has been added over period of time P.sub.2, the temperature is maintained at temperature T.sub.2 during a period of time P.sub.23 of from 30 min to 300 min.

10. The process in accordance with claim 1 wherein at the end of step b) the metallic compounds are separated from the products using distillation at reduced pressure, application of a magnetic field, or simple filtration and then are recycled for the conversion of another batch of fatty acid or fatty acid derivative or a mixture thereof comprising at least 10 mol %, based on the entire amount of fatty acid or fatty acid derivative, of fatty acid having 12 carbon atoms or less or derivative of such fatty acid.

11. The process according to claim 1, wherein an internal ketone manufactured through the decarboxylative ketonization of the fatty acid, fatty acid derivative or mixture thereof is subjected to a hydrogenation reaction to manufacture a secondary fatty alcohol.

12. The process according to claim 11, wherein the secondary fatty alcohol is further converted to an internal olefin by a dehydration reaction.

13. The process according to claim 12, wherein the internal olefin obtained after the dehydration is sulfonated followed by an alkaline hydrolysis to obtain an internal olefin sulfonate.

14. The process in accordance with claim 2 wherein temperature T.sub.1 is from 275° C. to 295° C.

15. The process in accordance with claim 3 wherein temperature T.sub.1 is from 280° C. to 295° C.

16. The process in accordance with claim 1, wherein the elementary metal or metal compound is selected from the group consisting of iron powder, magnetite and magnesium oxide.

17. The process in accordance with claim 1, wherein the elementary metal or metal compound is iron powder.

18. The process in accordance with claim 1, wherein the elementary metal or metal compound is magnetite.

19. The process in accordance with claim 1, wherein the elementary metal or metal compound is magnesium oxide.

Description

EXAMPLES

Example 1

Synthesis of C.SUB.15.-C.SUB.35 .Ketones Cut Starting from a C.SUB.8.-C.SUB.18 .Coco Saturated Fatty Acids Cut Using Magnetite (Fe.SUB.3.O.SUB.4.) as the Catalyst (12.5 mol % of Fe)

(1) The reaction was carried out under argon in a 750 mL reactor equipped with mechanical stirring, Dean Stark apparatus and an addition funnel. In the reactor, 9.3 g (0.04 mol) of magnetite Fe.sub.3O.sub.4 were dispensed and 200 g (0.97 mol) of the coco saturated fatty acids cut (with the following distribution: C8: 7 wt %, C10: 8 wt %, C12: 48 wt %, C14: 17 wt %, C16: 10 wt %, C18: 10 wt %) was introduced into the addition funnel.

(2) A first partial amount of 50 g of fatty acids was added into the reactor and the temperature was brought to T.sub.1=290° C. The mixture was stirred at this temperature during 4 hours. During this time the color of the media changed to black and H.sub.2O was formed. FTIR analysis of the crude mixture showed complete formation of intermediate iron carboxylate complexes.

(3) The temperature was then raised to T.sub.2=330° C. and the mixture was stirred at this temperature during 2 hours. During this time the intermediate iron carboxylate complexes were decomposed to fatty ketones, iron oxide and CO.sub.2. The remaining fatty acids (150 g) are slowly introduced into the reactor such that the temperature of the reaction medium didn't fall down below 320° C. and at a flow rate which allowed keeping concentration of fatty acids in the reaction medium very low (for example with an addition flow rate of around 25 g fatty acids/hour).

(4) Practically this was done through the successive slow additions (1 hour per addition) of 3 portions of 50 g of melted fatty acids with 1 hour of stirring at 330° C. between each addition.

(5) At the end of the last addition, the crude medium is stirred at 330° C. during 2 hours and the reaction progress is monitored through FTIR. When the reaction is completed (no more iron complex detected by FTIR), the mixture is allowed to cool down at room temperature and 400 mL of CHCl.sub.3 is added to the crude media. The mixture is stirred at 40° C. in order to solubilize the product. The obtained suspension was filtered on a silica plug (400 g) and eluted using 3 L of chloroform. Evaporation of the solvent afforded 160 g (0.456 mol) of the product C.sub.15-C.sub.35 ketones as a white wax (94% isolated yield) analytically pure.

Example 2

Synthesis of C.SUB.15.-C.SUB.35 .Ketones Cut Starting form a C.SUB.8.-C.SUB.18 .Coco Saturated Fatty Acids Cut Using Magnetite (Fe.SUB.3.O.SUB.4.) as the Catalyst (Molar Ratio Iron Metal:Carboxylic Acid Equivalent 1.2:22.1 or 5.4 mol %)

(6) The reaction was carried out under an inert atmosphere in a 7.5 L INOX 316 L jacketed reactor equipped with a mechanical strirrer and an exhaust tube in order to remove gas (H.sub.2O and CO.sub.2) generated during the reaction. The reactor was connected thanks to a insulated tube to a heated glass vessel containing 4093 g (19.7 moles) of the coco saturated fatty acids cut C.sub.8-C.sub.18 (with the following composition: C8: 7.7 wt %, C10: 6.2 wt %, C12: 48.4 wt %, C14: 18.2 wt %, C16: 9.1 wt %, C18: 9.9 wt %).

(7) 93 g of magnetite Fe.sub.3O.sub.4 (0.4 mol) followed by 503 g (2.4 mol) of the cut of saturated fatty acids C.sub.8-C.sub.18 were directly added into the reactor. The temperature of the media inside the reactor was progressively increased to T.sub.1=290° C. and the mixture was allowed to stir (140 rpm) during 4 h00 until complete disappearance of fatty acids and formation of intermediate iron carboxylate complex were observed by FTIR. Generation of water is observed during this step. Then the temperature inside the reactor was progressively increased to T.sub.2=310° C. and stirred at this temperature during 2 h00 in order to decompose the intermediate iron carboxylate complex to ketone, CO.sub.2 and iron oxide. The remaining melted fatty acids (4093 g) contained in the bottle were then slowly added into the reactor (thanks to a slight overpressure maintained in the bottle) at a flow which allows keeping the reaction media temperature slightly above 310° C. (310° C.-315° C.) and which avoids the accumulation of fatty acids inside the reactor (this can be checked easily thanks to regular FTIR analysis). Practically this has been achieved with a total addition duration of 14 h30.

(8) At the end of the addition, the reaction mixture was allowed to stir at 310° C. during an additional 5 h00 until complete disappearance of intermediate iron carboxylate complex was observed by FTIR.

(9) When the reaction was completed, the mixture was allowed to cool down at 80° C. and the crude was removed from the reactor, cooled down at room temperature and crushed into powder.

(10) The obtained product was dissolved into 25 L of CH.sub.2Cl.sub.2 and the resulting suspension filtered in order to remove insoluble iron oxide.

(11) The filtrate was washed several times using an aqueous solution of H.sub.2SO.sub.4 in order to remove soluble iron species from the product. The organic phase was dried, filtered and the solvent was evaporated under vaccuum to furnish 3750 g (10.6 moles) of the product fatty ketones as a dark brown wax (95% isolated yield) analytically pure.

(12) Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.