Acid composition for processing fatty acids
The invention relates to a composition comprising: at least one alkane-sulphonic acid R—SO 3 H wherein R represents a saturated, linear or branched, hydrocarbon chain comprising from 1 to 4 carbon atoms, which can or cannot be substituted by at least one halogen atom; sulphuric acid; and optionally at least one solvent; of which the proportions are defined in the description. The invention also relates to the use of the composition as a fatty acid esterification catalyst.
1. A composition comprising:
one or more alkane-sulphonic acids of formula R—SO 3 H wherein R represents a saturated, linear or branched, hydrocarbon chain comprising from 1 to 4 carbon atoms;
sulphuric acid;
and optionally at least one solvent;
wherein:
the proportion by weight of alkane-sulphonic acid in relation to the total weight of the alkane-sulphonic acid and sulphuric acid is comprised between 40% and 90%;
the proportion by weight of sulphuric acid in relation to the total weight of the alkane-sulphonic acid and sulphuric acid is comprised between 10% and 60%;
the proportion by weight of solvent relative to the total weight of the composition is comprised between 0% and 50%; and
the one or more alkane-sulphonic acids comprises methane-sulphonic acid.
2. The composition according to claim 1 wherein the solvent is chosen among water, alcohol and ether, alone or in combination.
3. The composition according to claim 1 wherein the solvent is water or a C 1 to C 3 alcohol, alone or in combination.
4. The composition according to claim 1 wherein the solvent is water or methanol, alone or in combination.
5. The composition according to claim 1 wherein the proportion by weight of solvent relative to the total weight of the composition is comprised between 5% and 35%.
6. A composition according to claim 1 , wherein the composition further comprises at least one corrosion inhibitor.
7. A composition according to claim 1 comprising at least one fragrance or one odorising agent, alone or in combination.
8. A method for manufacturing fatty acid esters comprising the following steps:
a/ placing at least one fatty acid into a reactor;
b/ adding at least one alcohol;
c/ heating the reaction medium;
d/ introducing the composition according to claim 1 as a catalyst;
e/ optionally, removing the water formed during the esterification reaction; and
f/ recovering the fatty acid esters
with step d being optionally performed at the same time as step a and/or step b.
9. The method according to claim 8 wherein the catalyst/fatty acid molar ratio is comprised within a range of from 0.001 to 1.
10. The composition according to claim 1 , wherein the proportion by weight of alkane-sulphonic acid in relation to the total weight of the alkane-sulphonic acid and sulphuric acid is comprised between 44% and 89%, and wherein the proportion by weight of sulphuric acid in relation to the total weight of the alkane-sulphonic acid and sulphuric acid is comprised between 11% and 56%.
11. The composition according to claim 10 , wherein the proportion by weight of solvent relative to the total weight of the composition is comprised between 5% and 35%.
12. The method of claim 8 wherein step d is performed at the same time as step a and/or step b.
13. The method according to claim 8 wherein the catalyst/fatty acid molar ratio is comprised within a range of from 0.01 to 0.5.
14. The method according to claim 8 wherein the catalyst/fatty acid molar ratio is comprised within a range of from 0.02 to 0.2.
15. The composition according to claim 1 wherein the one or more alkane-sulphonic acids, in addition to the methane-sulphonic acid, includes one or more, in any combination and in any mixture proportion, of ethane-sulphonic acid, n-propane-sulphonic acid, iso-propane-sulphonic acid, n-butanesulphonic acid, iso-butanesulphonic acid, sec-butane-sulphonic acid, tert-butanesulphonic acid.
16. The composition according to claim 1 wherein the one or more alkane-sulphonic acids is limited to the methane-sulphonic acid.