Process for preparing aromatics from naphtha

The process for producing xylene and a fuel gas from naphtha which comprises the steps of

• a. desulfurizing the naphtha;
• b. catalytically reforming the product stream of step (a) under conditions adapted to produce a substantial amount of aromatic compounds and which produces by-product hydrogen;
• c. thermally hydrocracking the product stream of step (b) under conditions which use less than all of the byproduct hydrogen from the reforming step;
• d. separating gaseous hydrogen and lighter hydrocarbons from the product stream of step (c);
• e. recycling the gaseous hydrogen from step (d) for use in said desulfurizing, reforming and hydrocracking steps;
• f. fractionating the liquid product stream of step (c) to withdraw a paraffin stream and a xylene -- rich stream as products of said process and to remove a toluene -- rich stream, and a C.sub.9.sup.+ rich stream;
• and
• g. transalkylating the toluene-rich and C.sub.9.sup.+ rich streams of step (f) and recycling the transalkylation reaction products to the fractionation step (f).

The process for producing paraxylene and a fuel gas from naphtha which comprises the steps of

• a. desulfurizing said naphtha;
• b. catalytically reforming the product stream of step (a) under conditions adapted to produce a substantial amount of aromatic compounds;
• c. thermally hydrocracking the product stream of step (b);
• d. separating gaseous hydrogen and lighter hydrocarbons from the product stream of step (c) to provide a liquid bottoms stream;
• e. fractionating the liquid bottom stream of step (d) to withdraw overhead a paraffin stream as product of said process from an aromatic bottoms stream;
• f. fractionating the aromatic bottoms stream from step (e) to withdraw overhead a benzene-rich stream as product of said process from a toluene-containing bottoms stream;
• g. fractionating the toluene-containing bottoms stream from step (f) to withdraw overhead a toluene-rich stream from a paraxylene-containing bottoms stream;
• h. fractionating the paraxylene-containing bottoms stream from step (g) to remove overhead a paraxylene-rich stream from a heavier aromatic bottoms stream;
• i. withdrawing paraxylene as product of said process from said paraxylene-rich stream of step (h), and the remaining liquid from said paraxylene-rich stream is recycled to step (e);
• j. fractionating the heavier aromatic bottoms stream from step (h) to remove an overhead stream which is passed together with the overhead stream from step (g) to a transalkylation reactor, and
• k. passing liquid reaction product stream from said transalkylation reactor to step (e).