Technology Profile: Benzene Production from Pyrolysis Gas
By Chemical Engineering |
This column is based on “Benzene Production from Pygas,” a report published by Intratec. It can be found at: www.intratec.us/analysis/benzene-production-cost.
Benzene is the simplest and most important industrial aromatic hydrocarbon. It is a versatile petrochemical building block, and is an intermediate for several industrially important commodity chemicals and polymers, such as ethylbenzene, cumene, cyclohexane and others. Benzene is used in the production of pharmaceuticals, specialty chemicals, plastics, resins, dyes and pesticides.
The following paragraphs describe a process for benzene production from pyrolysis gasoline (pygas; a naphtha-range petroleum product with high aromatics content). Figure 1 presents a simplified flow diagram.
Figure 1. The diagram shows a benzene production process from pyrolysis gasoline[/caption]
Prefractionator. Pyrolysis gasoline is fed to a prefractionator, in which the C6 fraction is separated from the charge stock and then directed to the hydrogenation treatment section. Two byproduct streams, one composed of C5 and lighter hydrocarbons and the other of C7 and heavier hydrocarbons, are removed from the prefractionator.
Hydrogen treatment. Along with hydrogen, the C6 cut from…