PROCESS FOR THE PRODUCTION OF ALKANESULFONIC ACIDS

Abstract

A process for the manufacturing of alkanesulfonic acid by reaction of an alkane with an anhydride in the presence of sulfuric acid and a starter at ambient temperature or higher and under pressure.

Claims

1-17. (canceled)

18. A process for the manufacturing of alkanesulfonic acid, R—SO.sub.3H, wherein R stands for C.sub.1-C.sub.4 alkyl, comprising reacting an anhydride with sulfuric acid and an alkane, R—H, in the presence of a peroxide starter at ambient temperature or higher and under pressure higher than ambient pressure, wherein the anhydride is RSO.sub.2OSO.sub.2R.

19. The process according to claim 18, wherein the starter is aqueous hydrogen peroxide, monomethylperoxydisulfate and salts thereof, dimethylperoxodisulfate and salts thereof, peroxodisulfuric acid and salts thereof, or peroxomonosulfuric acid and salts thereof.

20. The process according to claim 18, comprising the following steps: a) adding a peroxide starter to a mixture of the anhydride and sulfuric acid, b) contacting the alkane to said mixture at a pressure in the range between 10 and 120 bar, and c) setting the reaction temperature in the range of 20 to 80° C. for 1 to 30 hours.

21. The process according to claim 18, wherein R stands for methyl.

22. The process according to claim 18, wherein the molar ratios of anhydride to sulfuric acid is in the range of from 0.001: 1 to 1:1.

23. The process according to claim 18, wherein the molar ratios of anhydride to sulfuric acid is in the range of from 0.005: 1 to 0.80: 1.

24. The process according to claim 18, wherein the molar ratios of anhydride to sulfuric acid is chosen in the range of from 0.01: 1 to 0.70: 1.

25. The process according to claim 18, wherein R—SO.sub.3H is added as a further starting material.

26. The process according to claim 18, wherein SO.sub.3 is added as a further starting material.

Description

[0027] A further embodiment of this invention relates to a process for the manufacturing of alkanesulfonic acid, R—SO.sub.3H by reaction of an anhydride with sulfuric acid and an alkane, R—H, in the presence of a starter at ambient temperature or higher and under pressure higher than ambient pressure, comprising the following steps: [0028] 1) adding a starter to a mixture of the anhydride and sulfuric acid, [0029] 2) contacting the alkane to said mixture at a pressure in the range between 10 and 120 bar, preferably between 45 and 120 bar, more preferably between 75 and 110 bar, [0030] 3) setting the reaction temperature in the range of 20 to 80° C., preferably 35 to 70° C., most preferably 40 to 65° C., for 1 to 30 hours, preferably from 2 to 20 hours, most preferably from 3 to 15 hours,

[0031] wherein the starter is chosen from the group consisting of aqueous hydrogen peroxide, monomethylperoxodisulfate and salts thereof, dimethylperoxodisulfate and salts thereof, peroxodisulfuric acid and salts thereof, and peroxomonosulfuric acid and salts thereof, or from mixtures containing one or more of the starter compounds, and wherein the anhydride is chosen from the group consisting of RSO2OSO2R, anhydrides of mineral acids (preferably anhydrides of mineral acids other than SO.sub.3), anhydrides of organic acids, and of anhydrides of the general formula R—(C═O)—O—(C═O)—R′, where R′ has the same meaning as R, and R and R′ can be the same or different from each other. Preferably, R stands for methyl, more preferably, R and R′ stand for methyl.

[0032] A further preferred embodiment concerns the inventive process, wherein the molar ratio of anhydride to sulfuric acid is chosen in the range of from 0.001:1 to 1:1, preferably of from 0.005:1 to 0.80:1, most preferred from 0.01: 1 to 0.70: 1.

[0033] An additional preferred embodiment concerns the inventive process, wherein R—SO.sub.3H is added as a further starting material.

[0034] Another preferred embodiment concerns the inventive process in which SO.sub.3 is added as a further starting material.

[0035] In the inventive process, SO.sub.3 may additionally be added as an option, which does not seem to [0036] influence the reaction negatively.

[0037] Thus, it is possible to react a mixture with starter, anhydride and sulfuric acid, a mixture with starter, anhydride, sulfuric acid and R—SO.sub.3H, a mixture with starter, anhydride, sulfuric acid and SO.sub.3, and a mixture with starter, anhydride, sulfuric acid, SO.sub.3 and R—SO.sub.3H.

[0038] A further preferred embodiment of this invention relates to the inventive process, in which the pressure and/or temperature can be varied during the reaction, e.g. in case the pressure drops because of consumption of the alkane, it might be desirable to adjust the pressure accordingly by adding additional alkane to the reactor. By varying pressure and temperature, a person skilled in the art may wish to avoid negative feedback loops bases on his or her usual knowledge and skill.

[0039] An additional aspect of the present invention is also the use of at least one anyhdride, preferably an anhydride other than SO.sub.3, in a process for the manufacturing of alkanesulfonic acid, R—SO.sub.3H, wherein R stands for C.sub.1-C.sub.4 alkyl, by reaction with sulfuric acid and an alkane, R—H, in the presence of a starter, preferably peroxide starter, at ambient temperature or higher and under pressure higher than ambient pressure.

[0040] In a preferred embodiment of the inventive use, the starter is chosen from the group consisting of aqueous hydrogen peroxide, monomethylperoxydisulfate and salts thereof, dimethylperoxodisulfate and salts thereof, peroxodisulfuric acid and salts thereof, and peroxomonosulfuric acid and salts thereof.

[0041] In a further preferred embodiment of the inventive use, the anhydride is chosen from the group consisting of RSO.sub.2OSO.sub.2R, anhydrides of mineral acids and anhydrides of organic acids, preferably from the group consisting of RSO.sub.2OSO.sub.2R, anhydrides of mineral acids other than SO.sub.3 and anhydrides of organic acids, more preferably chosen from the group consisting of RSO.sub.2OSO.sub.2R and anhydrides of organic acids.

[0042] In a further preferred embodiment of the inventive use, the anhydride is selected from anyhdrides except SO.sub.3.

[0043] In general, the inventive process can be carried out in usual vessels such as a reactor or an autoclave. This vessel or reactor or autoclave can be made from any material stable under the reaction conditions, e.g. stainless steel, or steel with a lining like a glass-lining or lining from some polymer like PP, PE, PTFE or others. Preferably a stainless-steel autoclave is used. The vessel can be set-up with or without mixing, internally e.g. with a stirrer or other means, or externally—by means of a pump or any device with comparable functionality (e.g. jet nozzle, injector or the like)—via a mixing device, a heat exchanger, or the like.

[0044] After the reaction, the reaction mixture can be worked up by usual means such as cooling down the reaction vessel and decreasing the pressure to ambient pressure.

[0045] A preferred embodiment of this invention relates to the inventive process for the manufacturing of MSA, i.e. in which R stands for methyl.

[0046] In particular, one embodiment of this invention relates to a process for the manufacturing of MSA by reaction of MSAA with sulfuric acid and methane in the presence of a starter at ambient temperature or higher and under pressure higher than ambient pressure, comprising: [0047] 1) adding a starter to a mixture of MSAA and sulfuric acid, [0048] 2) contacting the alkane to said mixture at 10 to 120, preferably 45 to 120 bar, more preferably 75 to 110 bar, [0049] 3) setting the reaction temperature in the range of 20 to 80° C., preferably 35 to 70° C., most preferably 40 to 65° C., for 1 to 30 hours, preferably from 2 to 20 hours, most preferably from 3 to 15 hours,

[0050] wherein the starter is chosen from the group consisting of aqueous hydrogen peroxide, monomethylperoxydisulfate and salts thereof, dimethylperoxodisulfate and salts thereof, peroxodisulfuric acid and salts thereof, and peroxomonosulfuric acid and salts thereof, or from mixtures containing one or more of the starter compounds.

[0051] Another more preferred embodiment concerns the inventive process for the manufacturing of MSA by reaction of MSAA, wherein sulfuric acid, methane and optionally SO.sub.3 and optionally MSA in the presence of a starter at ambient temperature or higher and under pressure higher than ambient pressure, comprising: [0052] 1) adding a starter to a mixture of the anhydride, sulfuric acid, optionally SO.sub.3 and optionally MSA, [0053] 2) contacting the alkane to said mixture at 10 to 120, preferably 45 to 120 bar, more preferably 75 to 110 bar, [0054] 3) setting the reaction temperature in the range of 20 to 80° C., preferably 40 to 65° C., for 1 to 30 hours, preferably from 3 to 15 hours,

[0055] wherein the starter is chosen from the group consisting of aqueous hydrogen peroxide, monomethylperoxydisulfate and salts thereof, dimethylperoxodisulfate and salts thereof, peroxodisulfuric acid and salts thereof, and peroxomonosulfuric acid and salts thereof, or from mixtures containing one or more of the starter compounds.

[0056] In the following, the invention is further illustrated in an exemplary way.

EXAMPLES

[0057] The samples were characterized by .sup.13C-NMR spectroscopy using a Bruker Avance III HD 400 MHz (C.sub.6D.sub.6 was used in a capillary as the lock reference).

[0058] The yield of MSA was calculated by acidimetry: the samples were dissolved in 2-propanol and titrated with a tetrabutylammoniumhydroxide solution. MSA and H.sub.2SO.sub.4 were characterized by the obtained titration curves, where at pH turning point #1 the first proton of H.sub.2SO.sub.4 and MSA in total, and at pH turning point #2 the second proton of H.sub.2SO.sub.4 could be determined.

[0059] Example 1: To methanesulfonic acid anhydride (38.48 g, purchased from Apollo) dissolved in sulfuric acid (100%, purchased from Merck) (62.44 g) in an argon filled high pressure stainless-steel reactor (0.3 I volume) equipped with a glass liner, manometer and agitator, 15.254 g of a starter (obtained by adding 10.14 g H.sub.2O.sub.2 (70 wt.-%) in small portions to 149.98 g oleum (32 wt.-%) under continuous stirring over one hour and continuous cooling to a temperature in the range of 10 to 18° C.) were added, then nitrogen gas was pressed into the reactor (120 bar) in order to remove oxygen, then pressure was released to normal pressure). Next the reactor was pressurized with methane to 80 bar, the temperature was then raised to 50° C., thereafter the pressure was adjusted to and maintained at 100 bar throughout the reaction by adding additional methane from time to time. After nine hours the reactor was cooled to room temperature, then the pressure was released to normal pressure. A clear, colorless liquid was obtained.

[0060] The .sup.13C-NMR showed only one signal (39.1 ppm), which was assigned to MSA. Based on acidimetry, a yield of more than 97% of MSA was obtained, based on the theoretical amount of SO.sub.3 released from the reaction of MSAA with sulfuric acid.

[0061] Example 2: To 100 g of a solution consisting of 13 wt.-% methanesulfonic anhydride (purchased from Apollo), 30 wt.-% MSA (Lutropur® MSA 100 from BASF SE), 30 wt.-% H.sub.2SO.sub.4 (100% from Merck) and 27 wt.—% SO.sub.3 (obtained by distillation from oleum 65 wt.-%, BASF SE), in a argon filled high pressure stainless-steel reactor (0.3 I) equipped with a glass liner, manometer and agitator 0.55 ml of H.sub.2O.sub.2 (70 wt.-%) as starter were added. Then nitrogen gas was pressed into the reactor in order to remove oxygen (120 bar), thereafter the pressure was released to normal pressure. Next the reactor was pressurized with methane to 80 bar, the temperature was then raised to 50° C. and finally the pressure was adjusted to and maintained at 100 bar throughout the reaction by adding additional methane from time to time. After eight hours the reactor was cooled to room temperature, then the pressure was released to normal pressure. A clear, colorless liquid was obtained.

[0062] The .sup.13C-NMR data showed only one signal (39.0 ppm), which was assigned to MSA. Based on acidimetry, a yield of more than 93% of MSA was obtained, based on the theoretical amount of SO.sub.3 released from the reaction of MSAA with sulfuric acid and SO.sub.3 present in the reaction mixture. Thus, the presence of SO3 does not hinder the reaction of the anhydride (other than SO.sub.3) to form MSA.

[0063] Example 3: Phosphorpentoxide (15.08 g; 99% from Acros), 81.75 g sulfuric acid (100% from Merck) and 15.05 g of the same starter as obtained in example 1 were filled into an argon filled high pressure stainless-steel reactor (0.3 I) equipped with a glass liner, manometer and agitator. Then nitrogen gas was pressed into the reactor in order to remove oxygen (120 bar), thereafter pressure was released to normal pressure. Next the reactor was pressurized with methane to 80 bar, the temperature was then raised to 50° C. and finally the pressure was adjusted to and maintained at 100 bar throughout the reaction by adding additional methane from time to time. After 23.5 h the reactor was cooled to room temperature, then the pressure was released to normal pressure. A clear, colorless liquid was obtained.

[0064] The .sup.13C-NMR data showed only one signal (38.7 ppm), which was assigned to MSA. Based on acidimetry, a yield of more than 90% of MSA was obtained, based on the theoretical amount of SO.sub.3 released from the reaction of MSAA with sulfuric acid in the reaction mixture.

[0065] The experimental examples show that using certain anhydrides as mentioned in claim 1 of this invention (for example, organic anhydrides like, for example, MSAA) to set free sulfur trioxide from sulfuric acid, works well in a process for manufacturing alkanesulfonic acids from alkane with a peroxide starter. The storage and handling of pure sulfur trioxide and/or oleum may thus be avoided.

[0066] Furthermore, it has been shown that using certain other anhydrides, for example from mineral acids, also works in a process for manufacturing alkanesulfonic acids from alkane with a peroxide starter.