| 摘要 |
<p>Low sulfur gasoline is produced by fractionating in a fractionator (10) a sulfur-containing naphtha into a low boiling fraction in which the majority of the sulfur is present in the form of mercaptans and a higher-boiling fraction in which the sulfur is predominantly in the non-mercaptan form. The low boiling fraction is desulfurized by mercaptan extraction in an extractor (4) which retains the olefins present in this fraction. The second fraction is desulfurized by hydrodesulfurization in a hydrotreater (15) which results in some saturation of olefins and loss of octane. The octane loss is restored by treatment in a reactor (17) 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 of mercaptans which are removed in a final hydrotreatment.</p> |
