Aromatics are produced by separation from Gasoline cuts. Especially the Pyrolisis Gasoline of Steamcrackers is an excellent source for BTX recovery by an extractive distillation process.
For aromatics recovery Linde's customers can choose between various well proven licensed processes. The process for processing of aromatic rich streams, such as pyrolysis gasoline consists of a catalytic selective hydrogenation for conversion of diolefins to monoolefins.
This section is followed by an intermediate fractionation for removal of C5 and C8 + components.
The remaining C6 - C7 components are then routed to a full-hydrogenation, in which non-aromatics are converted into the respective paraffins. Sulfur is also removed in this step. The bottom product of the subsequent stabilizer column is then routed to the extractive distillation section. Added solvent enables the distillative separation of paraffins, naphthenes and aromatics.
The nonaromatics are contained in the overhead product, which is routed to a nonaromatic solvent recovery column and the bottom product contains all aromatics, which are routed to the aromatic solvent recovery column. The overhead of this column is then processed in the benzene column, in which the separation of benzene and toluene takes place.