Patent ID: 7709692

Claim:
A process for the production of para-diethyl benzene from a mixed aromatic feedstock comprising: (a) ethylbenzene, (b) at least one other aromatic or non-aromatic compound wherein the aromatic compound is selected from the group consisting of benzene, alkylated benzene having alkyl group with carbon number 1 to 6, mono-alkyl aromatics, dialkyl aromatics, trialkyl aromatics, tetraalkyl aromatics, pentaalkyl aromatics, hexaalkyl aromatics, and a mixture thereof, and the non-aromatic compound is selected from the group consisting of any isomers having carbon number in the range of C 1 -C 11 and a mixture there of, and (c) optionally an ethylating agent, said process comprising following the steps in sequence of: (i) contacting the feedstock under conditions sufficient to affect the conversion by disproportionation and alkylation of ethylbenzene, and optionally in presence of a carrier gas selected at least one from nitrogen, hydrogen, steam or a mixture thereof, with a selectivated metallosilicate composite catalyst wherein said selectivated metallosilicate composite catalyst is prepared by (i) contacting an intermediate pore metallosilicate extrudate with water soluble or water insoluble organosilicon compound in a solvent selected from the group consisting of lower aliphatic alcohols, C 5 -C 10 saturated linear or cyclic hydrocarbons, C 6 -C 8 aromatics or mixture thereof, for 0.5 to 48 hours, and then recovering the solvent; (ii) combining the organosilicon compound treated metallosilicate with 1 to 200 percent of the mass of the metallosilicate of water or water vapor, and then drying the catalyst at a temperature of from 80 to 130° C. for from 1 to 20 hours; (iii) repeating the steps (i) and (ii) for any number of times; and (iv) calcining the catalyst in an oxygen containing atmosphere sufficient to remove the organic material and to deposit siliceous matter on the metallosilicate at a temperature in the range of from 160 to 800° C. for 2 to 20 hours wherein the calcining step is not repeated after each intermediate of steps (i) and (ii); and (2) recovering a product stream containing at least 95 wt % para-diethyl benzene, the product stream being substantially free from other isomers of diethylbenzene, C 8 aromatics, C 9 aromatics, C 10+ heavy aromatics other than diethylbenzene isomers; sulphur, halogen, olefinic compound and carbonyl compounds wherein the reactor effluent from step (1) or the pure recovered product from step (2) or an intermediate crude product stream containing at least 88 weight percent para-diethylbenzene along with heavy hydrocarbons of carbon number 10 or above is contacted with a clay material selected from the group consisting of montmorillonite, bentonite, attapulgite and a mixture thereof.