7 098 370

7,098,370 Title:

Process for the production of phenylalkanes using a catalyst that contains at least one heteropolyacid

The invention relates to a process for the production of a mixture of compounds that comprises for the most part at least one mono-alkylbenzene that belongs to the group that is formed by the 2-, 3-, 4-, 5- and 6-phenylalkanes by alkylation of benzene with at least one monoolefin that comprises at least two carbon atoms in its molecule, in the presence of a catalyst that comprises 12-tungstophosphoric acid and/or 12-tungstomolybdic acid, deposited on a substrate that develops a large specific surface area and a high pore volume and that comprises a majority proportion of zirconium oxide (ZrO.sub.2).

The invention claimed is:

1. A process for the production of a mixture of compounds comprising at least one 2-, 3-, 4-, 5- or 6-phenylalkane, said process comprising alkylating benzene in areaction zone with at least one monolefin being at least two carbon atoms, in the presence of catalytic quantity of a finished catalyst comprising at least one of 12-tungstophosphoric acid or 12-tungstomolybdic acid on a substrate, said substrateconsisting essentially of zirconium oxide in an amount equal to at least 50% by weight of the finished catalyst and a minor amount of a binder that is alumina, said alkylating being conducted under a pressure of 1 to 10 MPa, a temperature of 50 to300.degree. C., an hourly volumetric flow rate of about 0.5 to about 50 h.sup.-1, and a benzene/olefin molar ratio of 1:1 to 20:1.

2. A process according to claim 1, comprising producing a mixture of 2-, 3-, 4-, 5- or 6-phenylalkanes simultaneously.

3. A process according to claim 1, wherein the monoolefin is a linear olefin.

4. A process according to claim 1, wherein the monoolefin is a branched olefin.

5. A process according to claim 1, wherein the monoolefin comprises 9 to 16 carbon atoms in its molecule.

6. A process according to claim 1, wherein the monoolefin comprises 10 to 14 carbon atoms in its molecule.

7. A process according to claim 1, wherein the substrate of the catalyst comprises a majority proportion of zirconium oxide and not more than 25% of said alumina binder.

8. A process according to claim 1, said substrate having a specific surface area of 50 to 500 m.sup.2/g and a pore volume of 0.2 to 0.9 cm.sup.3/g and said catalyst comprising 10 to 55% by weight of said at least one of 12-tungstophosphoricacid or 12-tungstomolybdic acid.

9. A process according to claim 1, wherein the catalyst is in the form of balls or extrudates.

10. A process according to claim 1, wherein the catalyst has a mechanical resistance sufficient to provide a bed crushing value greater than about 0.7 MPa.

11. A process according to claim 1, further comprising fractionating the resultant mixture of compounds into a first fraction containing unconverted benzene, a second fraction containing at least one unconverted olefin, a third fractioncontaining 2-, 3-, 4-, 5- or 6-phenylalkanes, and a fourth fraction containing at least one polyalkylbenzene, and recycling at least a part of the said fourth fraction to the alkylation zone.

12. A process according to claim 1, further comprising fractionating the resultant mixture of compounds into a first fraction containing unconverted benzene, a second fraction containing at least one unconverted olefin, a third fractioncontaining at least one phenylalkane, and a fourth fraction containing at least one polyalkylbenzene, and reacting said fourth fraction at least in part in a transalkylation zone, different from said reaction zone for alkylating benzene, in contact witha transalkylation catalyst under conditions for forming mono-alkylbenzene by reaction between polyalkylbenzene(s) and benzene.

13. A process according to claim 12, wherein the transalkylation zone is under a pressure of about 1.5 to about 10 MPa, a temperature of about 100 to about 500.degree. C., an hourly volumetric flow rate of about 0.5 to about 50 h.sup.-1, and abenzene/polyalkylbenzene molar ratio of about 2:1 to about 50:1.

14. A process according to claim 11, further comprising recycling the first fraction at least in part to the alkylation zone.

15. A process according to claim 14, further comprising recycling the second fraction at least in part to the alkylation zone.

16. A process according to claim 1, wherein the catalyst comprises 12-tungstophosphoric acid.

17. A process according to claim 1, wherein the catalyst of zirconium oxide in the substrate is equal to at least 75% by weight of the finished catalyst.

18. A process according to claim 16, wherein the catalyst of zirconium oxide in the substrate is equal to at least 75% by weight of the finished catalyst.

19. A process according to claim 18, wherein the monoolefin is a linear olefin.

20. A process according to claim 8, wherein the catalyst of zirconium oxide in the substrate is equal to at least 75% by weight of the finished catalyst.

21. A process according to claim 9, wherein the specific surface is 80 450 m.sup.2/g and the pore volume is 0.3 0.8 cm.sup.3/g.