Mobil Oil Corporation

Michael S Sarli

Stuart S Shih

David L Fletcher

Timothy L Hilbert

Mohsen N Harandi

Arthur A Chin

Bernard M Gillespie

Kenneth W Smith

Frederick J Krambeck

Daria N Lissy

Stephen J McGovern

Peter J Owens

Richard C Kovacs

W Rodman Derr, Jr

Hartley Owen

Charles T Kresge

Quang N Le

Ivy Dawn Johnson

Garry W Kirker

Dominick N Mazzone

Ajit V Sapre

Nick Allen Collins

Hye Kyung Timken

Michael E Landis

Kathleen M Keville

Sadi Mizrahi

Minas R Apelian

David A Pappal

Birbal Chawla

Paul P Durand

Walter R Derr

Edward F Kondis

Dominik N Mazzone

Douglas S Diez

Timothy T Hilbert

A process for catalytically desulfurizing cracked fractions in the gasoline boiling range to acceptable sulfur levels uses an initial hydrotreating step to desulfurize the feed with some reduction in octane number, after which the desulfurized material is treated with a self-bound or binder-free zeolite to restore lost octane. The process may be utilized to desulfurize catalytically and thermally cracked naphthas such as FCC naphtha as well as pyrolysis gasoline and coker naphthas, while maintaining octane so as to reduce the requirement for reformate and alkylate in the gasoline blend. The self-bound catalyst offers advantages in activity and permits the process to be carried out at lower temperatures.

Gasoline upgrading process

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst, preferably a catalyst comprising an intermediate pore size zeolite, such as ZSM-5, and a large pore size zeolite, including a metal hydrogenation function, such as a faujasite, preferably USY, which contains nickel and molybdenum. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. Use of the intermediate pore size zeolite and the large pore size zeolite is expected to provide more boiling point conversion than either zeolite alone under the same conditions.

Hydrocarbon upgrading process

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst containing, preferably an intermediate pore size zeolite such as ZSM-5 and a zeolite such as MCM-22. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment in a second step over a a first catalyst zone comprising a large pore size zeolite material and a second catalyst zone comprising an intermediate pore size material. Preferably, the large pore size material is zeolite beta and the intermediate pore size material is ZSM-5. The treatment in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

Low sulfur gasoline of relatively high octane number is produced from a cracked, sulfur-containing olefinic naphthas by hydrodesulfurization followed by treatment over an acidic catalyst comprising zeolite beta with a metal hydrogenation component, preferably a mild hydrogenation component such as molybdenum. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst under endothermic conditions in a second reaction zone. Heat is added to the endothermic reaction zone to initiate and maintain octane restoring reactions. The preferred acidic catalyst is an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. The addition of heat at the second zone prolongs hydrodesulfurization catalyst life by allowing a lower hydrodesulfurization reactor temperature. The addition of heat also maximizes octane increase in the second zone.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha and benzene-rich fraction by hydrodesulfurization in a first reaction zone and treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 in a second reaction zone to reduce the octane loss which takes place as a result of the hydrodesulfurization. The benzene-rich fraction can be cofed to the first reaction zone or the second reaction zone. The benzene-rich fraction is preferably a heart-cut reformate.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst defined by its x-ray diffraction pattern and preferably comprising the synthetic zeolite MCM-22. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

A process for producing a desulfurized gasoline boiling range product of relatively high octane number from a sulfur containing feed boiling in the naphtha boiling range by converting the feed in a first stage over a conventional hydrodesulfurization catalyst, and then converting at least the normally liquid portion of the product of this first stage conversion over a catalyst comprising a zeolitic behaving refractory solid having acid activity and shape selectivity to produce a product having a sulfur content within the required specifications, and an octane number which at least approaches the octane number of the feed.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization and treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 in an octane restoration step, followed by separation of a C.sub.9 -containing fraction, and recycling the C.sub.9 -containing fraction to the octane restoration step. A hydrocarbon fraction comprising C.sub.1 to C.sub.3 hydrocarbons may also be separated from the octane restored product and recycled for purposes of alkylating aromatic hydrocarbons and for this purpose, it may be advantageous to introduce a benzene-rich feed, such as a reformate, to the process. The treatment over the acidic catalyst in the octane restoration step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst, modified to reduce surface acidity, and preferably an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. In favorable cases, using feeds of extended end point such as heavy naphthas with 95 percent points above about 380.degree. F. (about 193.degree. C.), improvements in both product octane and yield relative to the feed may be obtained.

Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst comprising a zeolite sorbing 10 to 40 mg 3-methylpentane at 90.degree. C., 90 torr, per gram dry zeolite in the hydrogen form, e.g., ZSM-22, ZSM-23, or ZSM-35. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha. The use of the specified zeolite provides greater desulfurization, gasoline selectivity, and octane than obtained using ZSM-5.

Low sulfur gasoline is produced from a catalytically cracked, sulfur-containing naphtha by fractionating the naphtha feed into a number of fractions of differing boiling range and hydrodesulfurizing them by by feeding them into a hydrodesulfurization reactor at spaced locations along the length of the reactor in order of descending boiling range, with the highest boiling fraction first. Staged introduction of the feed into the hydrodesulfurization reactor in this way promotes desulfurization of the sulfur-rich, olefin poor back end of the feed while reducing the saturation of the high octane olefins in the olefin-rich, sulfur-poor front end, so preserving octane while achieving the desired desulfurization. The hydrodesulfurization is followed by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5. The treatment over the acidic catalyst in the second step restores octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product with an octane number comparable to that of the feed naphtha.

A moderate pressure hydrocracking process in which a highly aromatic, substantially dealkylated feedstock is processed to high octane gasoline and low sulfur distillate by hydrocracking over a catalyst, preferably comprising ultrastable Y and a Group VIII metal and a Group VI metal, in which the amount of the Group VIII metal content is incorporated at specified proportion into the framework aluminum content of the ultrastable Y component. The feedstock which is preferably a light cycle oil has an aromatic content of at least 50, usually at least 60 percent, and an API gravity not more than 25. The hydrocracking typically operates at 400-1000 psig at moderate to high conversion levels to maximize the production of monocyclic aromatics which provide the requisite octane value to the product gasoline. The distillate products from the hydrocracker are reduced in their sulfur content.

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Haddonfield, NJ, United States of America

Michael S Sarli