Process for operating a plant for preparing an alkanesulfonic acid

Patent metadata

Field	Value
Publication number	US-10494331-B2
Application number	US-201816129375-A
Country	US
Kind code	B2
Filing date	Sep 12, 2018
Priority date	Sep 13, 2017
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The present invention relates to a process for operating a plant for preparing an alkanesulfonic acid, wherein said alkanesulfonic acid is prepared by oxidation of an alkylmercaptan, dialkydisulfide and/or dialkylpolysulfide and the one or more alkyl radicals of the alkylmercaptan, dialkydisulfide and/or dialkylpolysulfide are identical with the alkyl radical of the alkylsulfonic acid to be prepared, characterized in that the oxidation is performed in the presence of an at least stoichiometric amount of an oxoacid of nitrogen, e.g. nitric acid, relative to the amount of said alkylmercaptan, dialkyldisulfide and/or dialkylpolysulfide during the start-up phase of the plant of the plant, wherein the start up phase comprises the steps adding an oxoacid of nitrogen to the reactor, adding sulfur-containing reactant progressively so that it is converted to alkanesulfonic acid, filling up the compile volume of the reactor by adding progressively sulfur-containing reactant and if needed oxoacid of nitrogen to make sure that it is in excess, once the reactor is full, transitioning out of the start-up phase by adding an oxygen containing fluid, and during the running phase, keeping the reaction volume full by balancing the volume of product withdrawn with the volume of sulfur-containing reactant added.

First claim

The invention claimed is:

1. A process for operating a plant for preparing an alkanesulfonic acid, wherein said alkanesulfonic acid is prepared by oxidizing an alkylmercaptan, dialkydisulfide and/or dialkylpolysulfide, such that the oxidizing occurs in the presence of an at least stoichiometric amount of an oxoacid of nitrogen relative to an amount of said alkylmercaptan, dialkyldisulfide and/or dialkylpolysulfide during a start-up phase of the plant, the process comprising:
i) providing an oxoacid of nitrogen in a reactor,
ii) feeding at least one of an alkylmercaptan containing stream, a dialkydisulfide containing stream, and a dialkylpolysulfide containing stream into the oxoacid of nitrogen in the reactor to give an alkanesulfonic acid containing product mixture, and
iii) repeating step ii) until an available inner volume of the reactor is filled completely with the alkanesulfonic acid containing product mixture obtained in step ii),
iv) feeding additional oxoacid of nitrogen into the reactor, when an amount of the oxoacid of nitrogen provided in step i) is not enough to fill the available inner volume of the reactor with the product mixture obtained in step ii),
v) feeding an oxygen containing fluid stream into the reactor, when the available inner volume of the reactor is completely filled with the product mixture obtained in the step ii) and/or in the step iii),
vi) removing at least part of the alkanesulfonic acid containing product mixture from the reactor, and
vii) feeding at least one of the alkylmercaptan containing stream, the dialkydisulfide containing stream, and the dialkylpolysufide containing stream into the reactor to yield a reaction mixture,
wherein:
said alkylmercaptan, dialkyldisulfide and/or dialkylpolysulfide is identical with the alkylmercaptan, dialkyldisulfide and/or dialkylpolysulfide of any of the preceding steps; and
a volume of the the alkylmercaptan containing stream, the dialkyldisulfide containing stream and the dialkylpolysulfide containing stream, fed into the reactor in step vii), equals a volume of the product mixture removed from the reactor in step vi).

2. The process according to claim 1 , wherein the start-up phase of the plant is performed in a batch mode or in a semi-continuous mode.

3. The process according to claim 1 , wherein the oxoacid of nitrogen is nitric acid and the process further comprises:
i′) providing at least an amount of the nitric acid according to the formula:

nitric
⁢

⁢

acid
⁢

[
mol
]

>

(

available
⁢

⁢
inner
⁢

⁢
volume
⁢

⁢

reactor
⁢

[
l
]

*

density
⁢

⁢
alkanesulfonic
⁢

⁢

acid
⁢

[

kg
l

]

*
0.01

)

molar
⁢

⁢
weight
⁢

⁢
of
⁢

⁢
nitrogen
⁢

⁢

dioxide
⁢

[

kg
mol

]

in the reactor,
ii′) feeding at least one of the alkylmercaptan containing stream, the dialkydisulfide containing stream, and the dialkylpolysufide containing stream into the nitric acid of step i′) to give the alkanesulfonic acid containing product mixture, and
iv′) after consumption of the nitric acid in step ii′), feeding the oxygen containing fluid stream into the alkanesulfonic acid containing product mixture.

4. The process according to claim 3 , further comprising:
iii′) feeding water, further nitric acid, or a mixture thereof, into the reactor until a stirrer of the reactor is immersed in the alkanesulfonic acid containing product mixture.

5. The process according to claim 3 , further comprising:
v′) feeding at least one of the alkylmercaptan containing stream, the dialkydisulfide containing stream, and the dialkylpolysulfide containing stream and the oxygen containing fluid stream into the reactor until the available inner volume of the reactor is filled completely with the alkanesulfonic acid containing product mixture.

6. The process according to claim 1 , wherein the steps v) to vii) are performed in a continuous mode or in an essentially continuous mode.

7. The process according to claim 1 , wherein the oxygen containing fluid stream is fed into the reactor near to or under, a stirrer of the reactor.

8. The process according to claim 1 , wherein the alkanesulfonic acid is prepared from at least one of an alkylmercaptan with a C 1 to C 12 alkyl radical, a dialkyldisulfide with a C 1 to C 12 alkyl radical, and a dialkylpolysulfide with a C 1 to C 12 alkyl radical.

Assignees

• Evonik Degussa Gmbh

Inventors

• Fonfe Benjamin
• Cheung Chiu Kee
• Hartwig Ali
• Duerr Nadine

Classifications

• C07C303/16 Primary

  by oxidation of thiols, sulfides, hydropolysulfides, or polysulfides with formation of sulfo or halosulfonyl groups · CPC title

• C07C309/04

  containing only one sulfo group · CPC title

• C23C22/50

  Treatment of iron or alloys based thereon · CPC title