Patent ID: 8148592

Claim:
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).