Recherche dans les collections de brevets nationales et internationales
Une partie du contenu de cette demande n'est pas disponible pour le moment.
Si cette situation persiste, contactez-nous auObservations et contact
1. (WO1993019031) PROCEDE ET APPAREIL DE PREPARATION D'ETHERS ALKYLIQUES TERTIAIRES
Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

Claims:

1. A process for preparing alkyl ethers, wherein
- isoolefins or mixtures thereof are reacted with at least one lower aliphatic alcoho in the presence of a catalyst comprising an acid cation exchange resin in order to form tert-alkyl ethers,
characterized by
- carrying out the reaction between the isoolefins and the alcohols essentially in at least one side reaction zone (5 - 7; 15; 18; 43, 44), which is combined with a distillation column (3; 12; 19; 35) intended for product separation, by conducting at least a part of the liquid flow of the column through the reaction zone and remrning it to a lower tray than the one from which it was taken, and
- feeding alcohol used in the etherification reaction to at least one of the side
reaction zones (5 - 7; 15; 18; 43, 44).

2. The process according to claim 1, characterized by subjecting C4 to C6 isoolefins and possibly heavier isoolefins to the reaction.

3. The process according to claim 1, characterized by feeding 1 to 100 % o the alcohol used for etherification to the side reaction zone (5-7: 15; 18; 43, 44).

4. The process according to claim 1, wherein a reaction mixmre is formed of the isoolefins and the alcohol, and the reaction mixmre is fed through at least one prereact to the distillation column, characterized by feeding 1 to 30 % of die alcoho used for etherification to the side reaction zone (5-7; 15; 18; 43, 44).

5. The process according to claim 1, characterized by preparing the tertiary ether in a catalytic distillation reactor system, which comprises a distillation column (3 12; 35) and at least one external reactor (5 - 7; 15; 43, 44).

6. The process according to ciaim 5, wherein a total drawoff is taken to the side react characterized by remrning the reaction product of die side reactor to the nex tray below the drawoff tray.

7. The process according to claim 5, wherein a partial drawoff is taken to die sidereac-tor, characterized by remrning the reaction product of the side reactor to a tray below the drawoff tray, the return tray being selected such that the best total conversion is obtained.

8. The process according to any one of the previous claims, wherein a liquid stream is fed to the side reaction zone (18; 43, 44) from a tray above the feed tray (28: 36), characterized by conducting the reaction mixmre obtained from the side reaction zone to a tray below the feed tray (28; 36).

9. The process according to claim 5, characterized by using 1 to 20, preferably about 2 to 3 reactors (5 - 7; 15; 43, 44) connected to die distillation column.

10. The process according to claim 5, characterized by adjusting the temperamre and pressure of the side reactor (43, 44) and the recirculation temperamre of the side stream by heat exchangers (50, 52) in order to increase the edier yield.

11. The process according to claim 5, characterized by vaporizing die side reactor product at least partially before recirculating it to the column in order to increase the yield of heavier ethers.

12. The process according to claim 1, characterized by
- preparing the tertiary ether in a catalytic distillation reaction system, wherein a reaction zone (18) comprising a catalyst layer is placed in a distillation column
(19),
- by-passing the catalyst layer with the gas flow coming from underneath the
reaction zone (18) and
- routing a part of the liquid flow coming from above the reaction zone (18) past the catalyst layer and a part through it, the liquid which has flown through the laver being routed to below the feed trav.

13. The process according to claim 1, characterized by recycling the side stream taken from the column to below the feed of the olefins and de alcohol.

14. The process according to any one of the previous claims,
characterized by circulating the side stream taken from the column by the thermosiphon principle through the reactor (15) back to the distillation column.

15. An apparams for preparing alkyl ethers from isoolefins and lower aliphatic alcohols, the isoolefins of the feedstock and die alcohols being reacted in a distillation reactor system (3 - 7; 13, 15; 18, 19; 35, 43, 44) in the presence of a cation exchange resin in order to form tertiary alkyl ethers,
characterized in tiiat
- the distillation reactor system comprises a distillation column (3, 4; 13; 19; 35) suited for product separation and at least one side reaction zone (5 - 7; 15; 18; 4 44) connected to it, an essential part of the cation exchange resin of the catalytic distillation reactor system being placed in the side reactor, and
- at least one of the side reaction zones (7; 15; 18; 43) is provided with a feed nozzle for alcohol used for etherification.

16. The apparams according to claim 15, characterized in that at least 30 % of the cation exchange resin is placed in said side reaction zone (5 - 7; 15; 18; 43, 44).

17. The apparams according to claim 16, characterized in that all of the cation exchange resin is placed in said at least one side reaction zone (5 - 7; 15; 18; 43 44).

18. The apparams according to claim 15, characterized in that it comprises to 20, preferably 2 to 3 side reactors (5-7; 15; 43, 44).

19. The apparams according to claim 15, characterized in that a heat exchanger (16; 52) is connected to the discharge conduit of the side reactor (15; 44) fo at least partial vaporization of the liquid flow which is returned from the side reactor t the column (13; 35).

20. The apparams according to claim 15, characterized in that it includes heat exchangers (50.51) for heating the side stream which is conducted to die side reactors (43, 44).

21. The apparams according to claim 15, characteriz ed in tiiat the side reaction zone comprises a catalyst layer (18) combined widi de distillation column (19), fitted widi a first conduit (26) for conducting a gas flow coming from underneath the catalyst layer through the reaction zone, a second conduit (25) for by-passing de reaction zone with a part of the liquid coming from above the catalyst layer, and a third conduit (27) for conducting the liquid flow which has flown through the catalyst layer to the desired tray.

22. The use of an apparams according to any one of claims 15 to 21 for preparing

TAME, ETBE, TAEE or MTBE.