Pyrolysis gasoline catalyst

Enciforming [National Chemical reforming] A petroleum reforming process that converts pyrolysis gasoline to mixtures of propane, butane, and aromatic hydrocarbons, thereby obviating the usual hydrogenation and solvent extraction processes. The catalyst is a ZSM-5-type zeolite containing both iron and a platinum metal. Developed by the National Chemical Laboratory, Pune, India, since 1988, but not yet commercialized. 

Ralthydrierung [German, meaning cold hydrogenation] A process for selectively hydrogenating pyrolysis gasoline, a petroleum refining byproduct, at temperatures below 100°C. A palladium catalyst is used. 

It follows that regeneration may consist of either (i) removal of IS sometimes poisons, most often inhibitors or fouling agents, e.g., coke (hydrogenation catalysts, e.g., selective hydrogenation of pyrolysis gasoline) or (ii) redispersion of the active species (platinum catalysts) or (iii) both (hydrodesulfurization or catalytic reforming catalysts). 

H.A. Smits, Selective hydrogenation of model compounds for pyrolysis gasoline over a monolithic palladium catalyst, SPE thesis. Delft University of Technology, Delft, The Netherlands, 1994. 

Selective catalytic hydrogenation of dienes and polyenes to monoenes over nickel sulphide supported on alumina or silica finds application in the partial hydrogenation of soybean oil and isoprene in the presence of methylbutenes. A sulphided C0-W/AI2O3 catalyst has been proposed for the selective hydrogenation of dienes in pyrolysis gasoline. 

Overall yields of over 99% are achieved. Reaction is either in the liquid phase, using aluminum chloride catalyst, or in the vapor phase, using a boron trifluoride catalyst. Ethylbenzene can also be recovered by fractionation of some gasoline or naphtha fractions or some Cg fractions from aromatics recovery from pyrolysis gasoline (a by-product of ethylene production). Figure 6.8 shows U.S. production figures for both ethylbenzene and ethylene glycol. 

Table 19.2 Styrene conversion data for hydrogenation of pyrolysis gasoline and synthetic load using commercial catalysts after forced deactivation and r eneration procedures...

A second aspect of the reactivity of the gas oil pyrolyzate is the impact it has on catalyst performance. The catalysts in many of the hydrorefining schemes developed for pyrolysis gasoline are particularly sensitive to control of the distillation end point and to the inclusion of substantial quantities of sulfur. 

These considerations led us to studies of the combined processing of pyrolysis gasoline and gas oil. Catalyst performance, in particular, was recognized as a critical factor. When it was determined that catalyst life of available commercial hydro-treating catalysts was too short to give the desired plant onstream time, catalyst development became an integral part of the effort. 

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. 

The MBR process reduces the benzene content of light reformate, FCC gasoline, or pyrolysis gasoline to below 1 vol% while boosting pool octane up to one point. The zeolite catalyst alkylates benzene with light... 

This study aims to evaluate samples of commercial catalysts based on palladium or nickel, selected by the Petrochemical Company (COPESUL), comparing them for activity and selectivity for use in industrial drive pyrolysis gasoline hydrogenation. 

Table 15.6 Styrene conversion data for pyrolysis gasoline hydrogenation catalysts for commercial virgin nickel and palladium...

Ali J. The hydrogenation of pyrolysis gasoline (PyGas) over nickel and palladium catalysts 2012. PhD thesis. School of Chemistry University of Glasgow, http //theses.gla.ac.uk/3542/... 

Upgrading of the aromatic feedstock (pyrolysis gasoline) over bifunctional Pt catalysts on MFI, BEA, and faujasite (FAU) zeolites, and an amorphous silica-alumina [61] at 5 MPa and 350-450°C was performed in different directions the Pt/MFI catalyst was optimal for a steam cracker feedstock production, the Pt/BEA catalyst—for isoalkane-rich gasoline pool manufacture and the Pt/silica-alumina catalyst for severe aromatic reduction while controlling the extent of ring scission. 

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