Pyrolysis gasoline hydrotreating

The feedstock consists of a mixture of C8 aromatics typically derived from catalytically reformed naphtha, hydrotreated pyrolysis gasoline oran LPG aromatization unit. The feed may contain up to 40% ethylbenzene, which is converted either to xylenes or benzene by the Isomar reactor at a high-conversion rate per pass. Feedstocks may be pure solvent extracts or fractional heartcuts containing up to 25% nonaromatics. Hydrogen may be supplied from a catalytic reforming unit or any suitable source. Chemical hydrogen consumption is minimal. 

Axens/Uhde Benzene, Toluene Reformate and/or hydrotreated Pyrolysis gasoline BT cuts In extractive distillation, the addition of a selective solvent modifies the vapor pressures of the hydrocarbons in the feed in such a way that paraffinic and naphthenic components can be separated from the aromatics by distillation. 65 2009... 

HYDROCRACKING HYDRODESULFURIZATION TOLUENE DEALKYLATION CYCLOHEXANE XYLENES ISOMERIZATION HYDROTREATING OF PYROLYSIS GASOLINE HYDROFINING... 

ABB Lummus Global Benzene Toluene rich stream/pyrolysis gasoline Hydrodealkylation produces high-purity product, single-step process, no hydrotreating 29 1998... 

Isoprene monomer Methylacetylene-allene cone. Dicyclopentadiene Pyrolysis gasoline Hydrotr. C9 aromatics Alkyl naphthalene cone. Mixed xylenes Ethylbenzene... 

Hydrogenated pyrolysis gasoline. See Petroleum distillates, hydrotreated light, low-boiling... 

Synonyms Distillates (petroleum), light distillate hydrotreating process, low-boiling Hydrogenated pyrolysis gasoline ... 

In both cases the pyrolysis gasoline/gas oil feed enters at the top of the first reactor. A recycle stream of hydrotreated gas oil is injected with the feed. The recycle streams serve as a reactant diluent, a heat sink to aid in reactor temperature control and as a solvent for polymer removal. Multiple catalyst beds are employed in the reactors to aid in temperature control. Quench oil is injected between the beds for reaction heat control. The first stage is operated at temperatures in the range of 107-177 C and at hydrogen partial pressures of the order of 48-68 atmospheres. 

PROPERTIES OF HYDROTREATED GASOLINE FROM COMBINED PROCESSING OF PYROLYSIS GASOLINE/GAS OIL... 

The feedstocks will t3 ically be low value refinery or petrochemical streams, such as steam cracker by-products rich in C4 s, which have poor propylene selectivity when recycled to the steam cracker. The feedstock can include raffinates, catalytic cracked naphtha, coker naphtha, steam cracker pyrolysis gasoline, as well as synthetic chemical streams containing sufficient amounts of C4-C7 olefins. Dienes, sulfur, nitrogen and oxygenates in the feeds are preferably selectively hydrotreated prior to the conversion process. However, feeds with low levels of dienes, sulfur, nitrogen, metal compounds and oxygenates can be processed directly from FCC units, cokers or steam crackers without any pretreatment. 

Other stocks which may be upgraded by hydrotreating are thennally and catalytic cracked naphthas, straight-run naphthas abnormally high in contaminants, and coker gasolines. The latter are produced by the high-temperature pyrolysis of reduced fuel to coke and distiUate fractions. Naphthas to be used as specialty solvents also are treated to obtain premium products with respect to color, odor, and stability. 

Jones, S.B., Valkenburg, C., Walton, C.W. Elliott, D.C. (2009). Production of Gasoline and Diesel from Biomass via fast Pyrolysis, Hydrotreating and Hydrocracking A Design Case. PNNL-18284, U.S. Department of Energy, Pacific Northwest National Laboratory, Richland, WA. 

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