Gasoline-cycle oil upgrading process
AssigneeMobil Oil Corporation
InventorsDominick N. Mazzone, Samual A. Tabak, Hye Kyung C. Timken
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Abstract
Light cycle oil (LCO) is upgraded to a low sulfur gasoline by co-processing the LCO with a cracked, sulfur-containing olefinic naphthas by hydrodesulfurization followed by treatment over an acidic catalyst comprising zeolite beta with a metal 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. The zeolite beta catalyst is active for conversion of the higher boiling portions of the feed to products of low sulfur content in the gasoline boiling range.
Claims20
A process of upgrading a cracked, olefinic sulfur-containing feed fraction boiling in the gasoline boiling range while co-processing a light cycle oil, which method comprises:
- contacting a hydrocarbon feed comprising (i) a naphtha component boiling in the gasoline boiling range, which is a cracked, olefinic sulfur-containing feed fraction and (ii) a minor amount of a light cycle oil component having a boiling range within the range of 550.degree. to 800.degree. F., with a hydrodesulfurization catalyst in a first reaction zone, operating under a combination of elevated temperature, elevated pressure and an atmosphere comprising hydrogen, to produce an intermediate product comprising a normally liquid fraction which has a reduced sulfur content and a reduced octane number as compared to the feed;
- contacting the intermediate product in a second reaction zone with an acidic catalyst comprising zeolite beta, to convert at least a part of the intermediate product to a product comprising a fraction boiling in the gasoline boiling range having a higher octane number than the gasoline boiling range fraction of the intermediate product.
A process for simultaneously upgrading (i) a catalytically cracked, olefinic sulfur-containing feed fraction boiling in the gasoline boiling range and (ii) a light cycle oil fraction having a boiling range in the range of 500.degree. to 850.degree. F., which process comprises:
- hydrodesulfurizing a hydrocarbon feed of:
- (i) a naphtha component boiling in the gasoline boiling range and comprising a cracked, olefinic, sulfur-containing gasoline feed having a sulfur content of at least 50 ppmw, an olefin content of at least 5 percent and a 95 percent point of at least 325.degree. F., and
- (ii) a cycle oil component comprising from 1 to 20 volume percent, based on the volume of the feed, of a light cycle oil fraction produced by the catalytic cracking of a hydrocarbon feed, the light cycle oil fraction having a boiling range in the range of 500.degree. to 850.degree. F. and an API gravity from 8 to 30 and a hydrogen content from 6 to 12 percent, the hydrodesulfurization being carried out with a hydrodesulfurization catalyst in a hydrodesulfurization zone, operating under a combination of elevated temperature, elevated pressure and an atmosphere comprising hydrogen, to produce an intermediate product comprising a normally liquid fraction which has a reduced sulfur content and a reduced octane number as compared to the feed;
- contacting the intermediate product in a second reaction zone with a bifunctional catalyst having acidic and hydrogenation functionality, comprising zeolite beta and a metal hydrogenation component, to convert the intermediate product to a product comprising a fraction boiling in the gasoline boiling range having a higher octane number than the gasoline boiling range fraction of the intermediate product.
Dependencies are inferred from the claim text.