Combination dehydrocyclodimerization and dehydrogenation process for producing aromatic and olefin products

A process for producing aromatic and olefinic hydrocarbons comprising:

• a) flowing a hydrocarbon feedstream containing C.sub.2 -C.sub.6 aliphatic hydrocarbons into a dehydrocyclodimerization zone where said feedstream is contacted with a bed of a solid dehydrocyclodimerization catalyst at dehydrocyclodimerization conditions, thereby producing an effluent stream containing C.sub.6.sup.+ aromatics, hydrogen and C.sub.1 -C.sub.4 aliphatic hydrocarbons;
• b) flowing the effluent stream to a first separation zone and separating the stream to obtain a first bottoms stream containing C.sub.6.sup.+ aromatics and a first overhead stream containing hydrogen and C.sub.1 -C.sub.4 aliphatic hydrocarbons;
• c) flowing the first overhead stream to a dehydrogenation zone and contacting said steam with a dehydrogenation catalyst in the presence of hydrogen at dehydrogenation conditions, thereby producing a second effluent stream containing C.sub.3.sup.= /C.sub.4.sup.= olefins, hydrogen and unreacted C.sub.1 -C.sub.4 aliphatic hydrocarbons;
• d) flowing the second effluent stream to a gas recovery zone and separating the second effluent stream into a hydrogen stream, a fuel gas (C.sub.1 /C.sub.2) stream, a C.sub.3.sup.= /C.sub.4.sup.= olefins and a C.sub.3 -C.sub.4 recycle aliphatic stream;
• e) recycling the C.sub.3 -C.sub.4 aliphatic stream to the dehydrocyclodimerization zone of step (a).