This disclosure relates to a method of improving the yield-octane number relationship of a reformate or reformer effluent by contacting the same at conversion conditions in the presence of hydrogen with crystalline aluminosilicate zeolites characterized by (1) having a silica to alumina ratio greater than 15 (preferably greater than 20); (2) having been crystallized from a solution containing organic cations so that the aluminosilicate as synthesized contains organic cations and (3) having pore sizes such that the aluminosilicate sorbs methyl paraffins at said conversion conditions. The upgrading of reformate or reformer effluent can take place with or without added hydrogen and with or without a hydrogenation/dehydrogenation component.
A method and system for converting hydrocarbons with a dual cracking component catalyst comprising ZSM-5 is described wherein the products of a large pore size cracking catalyst are passed into a dense fluid bed of catalyst comprising ZSM-5 catalyst for the production of aromatics and/or olefins suitable for alkylation with a paraffin.
Improvements in the aromatization of hydrocarbons and in the alkylation of aromatic rings effected by contacting appropriate hydrocarbon feed streams with a ZSM-5 type of catalyst at prescribed temperature, pressure and space velocity conditions to convert the feed as required and desired, which improvements go to minimizing the production of polycyclic aromatics, particularly naphthalenes in the process and reducing coking of the catalyst during aromatization and/or alkylation by using as the catalyst a ZSM-5 type of crystalline aluminosilicate zeolite which has rhenium values deposited thereon and therein by ion exchange techniques.
A hydrocarbon fraction, preferably in the kerosene boiling range containing a substantial proportion of C.sub.9 + hydrocarbons is contacted with an n-paraffin fraction, such as n-pentane, over a catalyst of acidic functionality, such as Pd/zeolite beta, under conditions of hydrocracking sufficient to convert the feed to lower boiling range materials of high octane number. The n-paraffin cofeed promotes isomerization and suppresses production of n-paraffins.
A zeolite catalyst composition suitable for para-selective conversion of substituted aromatic compounds, e.g., conversion of aromatics to dialkylbenzene compounds rich in the 1,4-dialkylbenzene isomer. Such a composition comprises a zeolite catalyst component having a silica to alumina mole ratio of at least 12 and a constraint index of about 1-12, and a minor amount, e.g., at least 0.25 weight percent, of copper, silver and/or gold, and optionally phosphorus.
Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a low boiling fraction in which the majority of the sulfur is present in the form of mercaptans and a high-boiling fraction in which the sulfur is predominantly in non-mercaptan form such as thiophenes. The low boiling fraction is desulfurized by a non-hydrogenatile mercaptan extraction process which retains the olefins present in this fraction. The second fraction is desulfurized by hydrodesulfurization, which results in some saturation of olefins and loss of octane. The octane loss is restored by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5, to form a low sulfur gasoline product with an octane number comparable to that of the feed naphtha but which contains some recombined sulfur in the form or mercaptans which are removed in a final hydrotreatment.
