High temperature depressurization for naphtha mercaptan removal
AssigneeExxonMobil Research and Engineering Company
InventorsBruce R. Cook, Richard H. Ernst, Richard A. Demmin, John P. Greeley
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Abstract
The invention relates to naphtha hydrodesulfurization incorporating either high temperature depressurization or controlled heating for mercaptan removal. More particularly, the invention relates to a naphtha hydrodesulfurization process, wherein the hot naphtha exiting the desulfurization reactor contains mercaptans, most of which are removed without olefin loss, by depressurizing the hot naphtha, thermally treating the hot naphtha, or some combination thereof. The desulfurized naphtha may be cooled and condensed to a liquid, separated from the gaseous H2S, stripped and sent to a mogas pool.
Claims25
A naphtha desulfurization process, comprising
- (a) hydrodesulfurizing a naphtha which contains olefins and sulfur in the form of organic sulfur compounds, to form a hydrodesulfurization effluent at an initial temperature, the hydrodesulfurization effluent comprising a hot mixture of sulfur reduced naphtha at an initial pressure, H2S and mercaptans, and then
- (b) rapidly depressurizing for a depressurization time at least a portion of the hydrodesulfurization effluent to destroy at least a portion of the mercaptans to form more H2S and a depressurized naphtha further reduced in sulfur.
A naphtha desulfurization process, comprising:
- (a) hydrodesulfurizing a naphtha, the naphtha containing olefins and sulfur in the form of organic sulfur compounds, to form a hydrodesulfurization effluent at an initial temperature, the effluent comprising a hot mixture of sulfur reduced naphtha, H2S and mercaptans;
- and then
- (b) heating at least a portion of the hydrodesulfurization effluent to a final temperature greater than the initial temperature at a substantially constant total pressure for a heating time to destroy at least a portion of the mercaptans to form more H2S and a treated naphtha further reduced in sulfur.
A process according to claim6 wherein said hydrodesulfurization catalyst comprises Co and Mo catalytic metal components and wherein said naphtha feed contains from 0.1 to 0.7 wt. % sulfur in the form of organic sulfur compounds, and from 5 to 60 vol. % olefins.
Dependencies are inferred from the claim text.