Process for the purification of 1,4-butanediol
View Patent ↗A process for the purification of a crude liquid feed stream comprising 1,4-butanediol and a minor amount of 2-(4-hydroxybutoxy)-tetrahydrofuran and/or precursors thereof wherein the process comprises passing the crude feed in the presence of hydrogen in a reaction zone over a heterogeneous liquid tolerant copper catalyst in the liquid phase at hydrogenation conditions and recovering a purified stream of 1,4-butanediol having a lower amount of 2-(4-hydroxybutoxy)-tetrahydrofuran than the crude liquid feed stream.
1. A process for the purification of a crude liquid feed stream comprising 1,4-butanediol and a minor amount of 2-(4-hydroxybutoxy)-tetrahydrofuran and/or precursors thereof comprising
passing the crude liquid feed in the presence of hydrogen in a reaction zone over a heterogeneous liquid tolerant copper catalyst in the liquid phase at hydrogenation conditions; and
recovering a purified stream of 1,4-butanediol having a lower amount of 2-(4-hydroxybutoxy)-tetrahydrofuran than the crude liquid feed stream, wherein the crude liquid feed is a product stream from production of 1,4-butanediol which has not been subjected to prior purification.
2. A process according to claim 1 wherein hydrogen pressure is in the range of about 5 barg to about 150 barg.
3. A process according to claim 2 wherein the hydrogen pressure is about 35 barg to about 100 barg.
4. A process according to claim 1 wherein a temperature of the reaction zone is in the range of from about 20° C. to about 150° C.
5. A process according to claim 1 wherein a temperature of the reaction zone is in the range of from about 50° C. to about 130° C.
6. A process according to claim 1 wherein a liquid hourly space velocity is in the range of from about 0.1 to about 10.
7. A process according to claim 1 wherein a liquid hourly space velocity is in the range of from about 0.2 to about 5.
8. A process according to claim 1 wherein additional hydrogen is added.
9. A process according to claim 8 wherein the additional hydrogen is added at a flow rate of about 1 to about 50 normal liters per hour.
10. A process according to claim 8 wherein the hydrogen is added at a flow rate of about 5 and about 30 normal liters per hour.
11. A process according to claim 1 wherein the liquid tolerant copper catalyst is a copper chromite catalyst, a copper alumina catalyst, a copper zinc catalyst or a copper silica catalyst.
12. A process according to claim 1 wherein the catalyst is carried out in the presence of a promoter.
13. A process according to claim 12 wherein the promoter is manganese or barium.
14. A process for the production of at least one C 4 compound selected from 1,4-butanediol, tetrahydrofuran and γ-butyrolactone comprising:
(a) contacting a solution of a di-(C 1 -C 4 alkyl) maleate with hydrogen in a hydrogenation zone under ester hydrogenation conditions in the presence of a heterogeneous ester hydrogenation catalyst to convert the di-(C 1 -C 4 alkyl) maleate to the at least one C 4 compound and a minor amount of 2-(4-hydroxybutoxy)-tetrahydrofuran;
(b) recovering from the hydrogenation zone a product stream containing the at least one C 4 compound and a minor amount of 2-(4-hydroxybutoxy)-tetrahydrofuran as a crude feed stream; and
(c) without prior purification subjecting the crude feed stream to the process of claim 1 .