Process for making n-butyl esters from butadiene
View Patent ↗Process for making a butyl ester from butadiene, comprising (a) reacting butadiene with a saturated aliphatic monocarboxylic acid to form a mixture of n-butenyl and secondary butenyl esters, (b) separating the n-butenyl ester from the secondary butenyl ester, and (c) hydrogenating the n-butenyl ester separated in step (b) in the presence of a catalyst to the corresponding n-butyl ester.
1. A process for making a butyl ester from butadiene, said process comprising
a) reacting butadiene with a saturated aliphatic monocarboxylic acid in a reaction mixture containing water to form a mixture of n-butenyl and secondary butenyl esters, wherein the level of water in the reaction mixture is in the range from 0.05 to 5% w/w based on the carboxylic acid;
b) separating the n-butenyl ester from the secondary butenyl ester; and
c) hydrogenating the n-butenyl ester separated in step b) in the presence of a catalyst to the corresponding n-butyl ester.
2. A process as claimed in claim 1 , wherein the butadiene employed in step a) is in the form of a hydrocarbon mixture comprising butadiene.
3. A process as claimed in claim 1 , the secondary butenyl ester separated in step b) is i) recycled step a), ii) hydrogenated in the presence of a catalyst to produce sec-butyl ester, iii) thermally cracked to produce the starting butadiene and a saturated aliphatic monocarboxylic acid, or iv) further reacted.
4. A process as claimed in claim 1 , wherein the carboxylic acid is acetic acid.
5. A process as claimed in claim 1 , wherein step a) is carried out in the presence of a heterogeneous or homogeneous acidic catalyst.
6. A process as claimed in claim 5 , wherein the catalyst is a heterogeneous catalyst in the form of an ion-exchange resin.
7. A process as claimed in claim 5 , wherein the catalyst is a homogeneous catalyst in the form of triflic acid or a triflate salt.
8. A process for making butenyl esters from butadiene comprising reacting butadiene with a saturated aliphatic monocarboxylic acid in a reaction mixture containing water to form a mixture of n- butenyl and secondary butenyl esters, wherein the level of water in the reaction mixture is in the range from 0 . 05 to 5 % w/w based on the carboxylic acid.
9. A process of claim 8 wherein the n- butenyl ester is separated from the secondary butenyl ester.
10. A process as claimed in claim 8 , wherein the carboxylic acid is acetic acid.
11. A process as claimed in claim 8 , wherein the reaction is carried out in the presence of a heterogeneous or homogeneous acidic catalyst.
12. A process as claimed in claim 11 , wherein the catalyst is a heterogeneous catalyst in the form of an ion- exchange resin.
13. A process as claimed in claim 11 , wherein the catalyst is a homogeneous catalyst in the form of triflic acid or a triflate salt.
14. A process as claimed in claim 9 , wherein the carboxylic acid is acetic acid.
15. A process as claimed in claim 9 , wherein the reaction is carried out in the presence of a heterogeneous or homogeneous acidic catalyst.
16. A process as claimed in claim 15 , wherein the catalyst is a heterogeneous catalyst in the form of an ion- exchange resin.
17. A process as claimed in claim 15 , wherein the catalyst is a homogeneous catalyst in the form of triflic acid or a triflate salt.
18. A process of claim 8 wherein the saturated aliphatic monocarboxylic acid contains 1 to 6 carbon atoms.
19. A process of claim 9 wherein separated secondary butenyl ester is recycled to the butadiene- carboxylic acid reaction mixture.
20. A process of claim 19 wherein the saturated aliphatic monocarboxylic acid is acetic acid and the reaction of carboxylic acid and butadiene is carried out in the presence of a heterogeneous acidic catalyst.
21. A process of claim 8 wherein the butadiene employed is in the form of a hydrocarbon mixture comprising butadiene.