Desulfurization process
View Patent ↗This invention is a method of purifying fuel streams containing organosulfur impurities. The fuel stream is oxidized with an organic hydroperoxide in the presence of an oxidation catalyst to form a sulfone product. The alcohol product of the organic hydroperoxide is then removed from the oxidized fuel stream, followed by extraction of the sulfone product by solid-liquid extraction using solid adsorbents. The alcohol removal step is found to improve the adsorption capacity of the solid adsorbents.
1. A process comprising:
(a) contacting a fuel stream containing organosulfur impurities with an organic hydroperoxide in the presence of an oxidation catalyst to form an oxidized fuel stream, wherein a substantial portion of the organosulfur impurities are converted into sulfones and a substantial portion of the organic hydroperoxide is converted into an alcohol;
(b) removing the alcohol from the oxidized fuel stream to form an alcohol-reduced oxidized fuel stream; and
(c) extracting the sulfones from the alcohol-reduced oxidized fuel stream by solid-liquid extraction using a sulfone adsorbent.
2. The process of claim 1 wherein the organic hydroperoxide is t-butyl hydroperoxide and the alcohol is t-butyl alcohol.
3. The process of claim 1 wherein the oxidation catalyst is a titanium-containing silicon oxide catalyst.
4. The process of claim 3 wherein the titanium-containing silicon oxide catalyst is titania-on-silica.
5. The process of claim 1 wherein the alcohol is removed by distillation.
6. The process of claim 1 wherein the sulfone adsorbent is selected from the group consisting of silicas, aluminas, and silica-aluminas.
7. A process comprising:
(a) extracting organonitrogen impurities from a fuel stream containing organonitrogen and organosulfur impurities whereby the nitrogen content of fuel stream is reduced by at least 50 percent to produce a fuel stream having a reduced amount of organonitrogen impurities;
(b) separating and recovering the fuel stream having a reduced amount of organonitrogen impurities;
(c) contacting the separated fuel stream having a reduced amount of organonitrogen impurities with an organic hydroperoxide in the presence of a titanium-containing silicon oxide catalyst to form an oxidized fuel stream, wherein a substantial portion of the organosulfur impurities are converted into sulfones and a substantial portion of the organic hydroperoxide is converted into an alcohol;
(d) removing the alcohol from the oxidized fuel stream to form an alcohol-reduced oxidized fuel stream; and
(e) extracting the sulfones from the alcohol-reduced oxidized fuel stream by solid-liquid extraction using a sulfone adsorbent.
8. The process of claim 7 wherein the organonitrogen impurities are extracted by solid-liquid extraction using at least one organonitrogen adsorbent.
9. The process of claim 8 wherein the organonitrogen adsorbent is selected from the group consisting of aluminum oxide, silicon oxide, silica-alumina, zeolite Y, Zeolite X, ZSM-5, magnesium oxide, and sulfonic acid resin.
10. The process of claim 7 wherein the organonitrogen impurities are extracted by liquid-liquid extraction using at least one polar solvent.
11. The process of claim 10 wherein the polar solvent is selected from the group consisting of a C 1 –C 4 alcohol, a C 3 –C 8 ketone, water, and mixtures thereof.
12. The process of claim 10 wherein the polar solvent is a mixture of methanol and water.
13. The process of claim 7 wherein the organic hydroperoxide is t-butyl hydroperoxide and the alcohol is t-butyl alcohol.
14. The process of claim 7 wherein the titanium-containing silicon oxide catalyst is titania-on-silica.
15. The process of claim 7 wherein the alcohol is removed by distillation.
16. The process of claim 1 wherein the sulfone adsorbent is selected from the group consisting of silicas, aluminas, and silica-aluminas.