Gasoline upgrading process
Patent 5318690 Issued on June 7, 1994. Estimated Expiration Date: 
January 7, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 7, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3759821 3767568 Method for reducing the sulfur level of gasoline product Reduction of sulfur from hydrocarbon feed stock containing olefinic component Process for desulfurizing and blending naphtha Process for improving the octane number of cracked gasolines Desulfurization and isomerization of N-paraffins Process for upgrading a sulphur-containing feedstock Patent #: 5143596 InventorsAssigneeApplicationNo. 001681 filed on 01/07/1993US Classes:208/89, With hydrogen208/60, With subsequent reforming208/88, Refining208/92, Distillation208/211With preliminary treatment of feedExaminersPrimary: Myers, HelaneAttorney, Agent or FirmInternational ClassesC10G 035/00C10G 045/00 AbstractLow 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. | |
