Abstract: Aromatic transalkylation processes are described which reduce the hydrogen makeup gas requirement to the aromatic transalkylation unit and improve the energy efficiency of the aromatics complex. The processes may utilize a hot separator, optionally one or more flash drums, and optionally a stripper column. The aromatic transalkylation separator bottom liquid may be preheated and flashed to a low-pressure drum to separate light hydrocarbons, such C1 to C5, as a vapor stream from the aromatics rich liquid hydrocarbons stream. A portion of flash drum liquid may recycled back to a product condenser inlet as a sponge liquid to absorb the light hydrocarbons from the reactor effluent stream and thereby improve the hydrogen purity of the recycle gas (RG) without purging RG.

Abstract: A feed stream of cyclic paraffins may be separated to obtain an overhead of methylcyclopentane or cyclohexane and a bottoms stream cyclohexane or methylcyclohexane. The overhead stream may be subjected to separation of normal paraffins from non-normal paraffins with the former being isomerized or the entire overhead stream may be isomerized. In a further embodiment, the bottoms stream may be subjected to steam cracking. In an additional embodiment, the feed stream of cyclic paraffins may be formerly subjected to aromatic saturation.

Abstract: A feed stream of cyclic paraffins may be separated to obtain an overhead of methylcyclopentane or cyclohexane and a bottoms stream cyclohexane or methylcyclohexane. The overhead stream may be subjected to separation of normal paraffins from non-normal paraffins with the former being isomerized or the entire overhead stream may be isomerized. In a further embodiment, the bottoms stream may be subjected to steam cracking. In an additional embodiment, the feed stream of cyclic paraffins may be formerly subjected to aromatic saturation.