Catalytic transalkylation of dialkyl benzenes

1. A method for obtaining monoalkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 , comprising the following steps:

i) mixing dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene;

ii) reacting the mixture of dialkyl benzene compounds with alkyl chains having a size of C 10 to C 20 and benzene obtained in step i) in a transalkylation reactor comprising a smectite type catalyst with modified acidity comprising;

a) an X-ray powder diffraction pattern, characterized in that the most intense diffraction peak appears at the 2 theta angle corresponding to 5.74° and the remaining main peaks, ordered from greatest to lowest intensity, appear at 2 theta diffraction angles corresponding to 19.77°-26.33°-54.11°-61.85°-68.11° and 76.33°;

b) a total acidity of acid centers of 100 to 900 micromoles per gram,

c) a total specific area (BET) between 200 to 800 m 2 /g;

d) a total pore volume between 0.1 to 1 ml/g;

e) a distribution of macropores with a diameter comprised between 20 and 2000 angstrom;

f) a total silicon:aluminium ratio between 2.0:1.0-10.0:1.0;

g) between 0.5-4% by weight of magnesium;

h) between 0.2-3% by weight of iron;

i) between 0.1-2% by weight of calcium:

j) between 0.1-2% by weight of sulfur;

k) between 0.01-0.5% by weight of fluorine; and

l) between 0.0001-0.005% by weight of sodium,

iii) separating the product obtained in step ii) into a first fraction comprising unreacted benzene, into a second fraction comprising unreacted dialkyl benzene compounds with alkyl chains having a size of C 10 to C 20 and into a third fraction comprising the monoalkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 generated in the catalytic transalkylation reaction of the dialkyl benzene compounds with C 10 to C 20 alkyl chains with benzene;

iv) mixing the fraction comprising the unreacted dialkyl benzene compounds with alkyl chains having a size of C 10 to C 20 obtained in step iii) with fresh polyalkyl aromatic compounds;

v) recirculating the mixture obtained in step iv) to step i);

vi) mixing the unreacted benzene obtained in step iii) with fresh benzene; and

vii) recirculating the mixture of unreacted benzene and fresh benzene obtained in step vi) to step i).

2. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein benzene and the dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 are in a molar benzene:dialkyl benzene compounds ratio comprised between 1:1 and 100:1.

3. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the catalyst of the step ii) is arranged in the reactor in an arrangement selected from the group consisting of a fluidized bed, of a slurry reactor or of at least one catalytic fixed-bed.

4. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the transalkylation reaction of step ii) is carried out in a reactor configuration comprising at least one of the reactor configurations selected from the group consisting of: an independent fixed-bed reactor, at least two fixed-bed reactors in parallel, at least two fixed-bed reactors in series and combinations thereof.

5. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the separation step iii) is carried out by means of selective decomposition and/or distillation of by-products and/or selective adsorption.

6. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the optimal temperature for carrying out the transalkylation reaction is comprised between 150-250° C.

7. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the optimal pressure for carrying out the transalkylation reaction is comprised between 10-50 kgf/cm 2 .

8. A method for obtaining mono alkyl benzene compounds with an alkyl chain having a size of C 10 to C 20 by means of the catalytic transalkylation of dialkyl benzene compounds the alkyl chains of which have a size of C 10 to C 20 with benzene according to claim 1 , wherein the optimal liquid hourly space velocity (LHSV) is comprised between 0.5-5 h −1 .