1. 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; and
(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 wherein a substantial portion of the organosulfur impurities are converted into sulfones.
2. The process of claim 1 wherein the organonitrogen impurities are extracted by solid-liquid extraction using at least one adsorbent.
3. The process of claim 2 wherein the adsorbent is selected from the group consisting of aluminum oxide, silicon oxide, silica-alumina, Y zeolite, Zeolite X, ZSM-5, and sulfonic acid resin.
4. The process of claim 3 wherein the adsorbent is selected from the group consisting of aluminum oxide, silica-alumina, and Y zeolite.
5. The process of claim 1 wherein the organonitrogen impurities are extracted by liquid-liquid extraction using at least one polar solvent.
6. The process of claim 5 wherein the polar solvent is selected from the group consisting of alcohol, ketone, water, and mixtures thereof.
7. The process of claim 6 wherein the ketone is a C3-C8 aliphatic ketone.
8. The process of claim 7 wherein the ketone is acetone.
9. The process of claim 6 wherein the alcohol is a C1-C4 alcohol.
10. The process of claim 9 wherein the alcohol is methanol.
11. The process of claim 5 wherein the polar solvent is a mixture of methanol and water.
12. The process of claim 1 wherein the organic hydroperoxide is t-butyl hydroperoxide.
13. The process of claim 1 wherein the titanium-containing silicon oxide catalyst is titania-on-silica.
14. The process of claim 1 comprising an additional step after step (c) of removing the sulfones from the fuel stream by solid-liquid or liquid-liquid extraction.
15. A process comprising:
(a) extracting organonitrogen impurities from a diesel 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 diesel fuel stream having a reduced amount of organonitrogen impurities; and
(c) contacting the separated diesel fuel stream having a reduced amount of organonitrogen impurities with t-butyl hydroperoxide in the presence of a titania-on-silica catalyst wherein a substantial portion of the organosulfur impurities are converted into sulfones.
16. The process of claim 15 wherein the organonitrogen impurities are extracted by solid-liquid extraction using at least one adsorbent selected from the group consisting of aluminum oxide, silica-alumina and Y zeolite.
17. The process of claim 15 wherein the organonitrogen impurities are extracted by liquid-liquid extraction using at least one polar solvent selected from the group consisting of C1-C4 alcohol, C3-C8 aliphatic ketone, water, and mixtures thereof.
18. The process of claim 17 wherein the ketone is acetone.
19. The process of claim 17 wherein the alcohol is methanol.
20. The process of claim 17 wherein the polar solvent is a mixture of methanol and water.
21. The process of claim 15 comprising an additional step after step (c) of removing the sulfones from the diesel fuel stream by solid-liquid or liquid-liquid extraction.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A refrigeration system using working fluid in a closed-loop circuit, comprising:
a condenser;
an evaporator;
a pump to induce working fluid to flow from the evaporator to the condenser, where the pump produces a pressure differential;
a working fluid transfer device downstream of the condenser and fluidly connecting to the evaporator; and
a flow control valve operatively disposed between the downstream end of the evaporator and the upstream end of the condenser, wherein the flow control valve is responsive to at least one of a first pressure sensor disposed upstream of the flow control valve and a second pressure sensor disposed downstream of the flow control valve, and the flow control valve being constructed and arranged to selectively control the timing of the flow interruption so as to occur a plurality of times per second.
2. A refrigeration system in claim 1, further comprising:
a control circuit operatively connected to the flow control valve, the pump, the condenser, the first pressure sensor, and the second pressure sensor.
3. A refrigeration system in claim 1 further comprising:
a dryer which is fluidly interposed between the working fluid transfer device and the condenser for removing predetermined contaminants from the working fluid.
4. A refrigeration system in claim 1, wherein the working fluid transfer device which fluidly connects the condenser and the evaporator, comprises a selectively operable valve having a variable orifice for controlling the amount of working fluid which is permitted to be released into the evaporator.
5. A refrigeration system in claim 1, the pump is adapted to selectively pump fluid therethrough in a timed relationship with the opening of the flow control device.
6. A refrigeration system using working fluid in a closed-loop circuit, comprising:
a condenser;
an evaporator;
a pump to induce working fluid to flow from the evaporator to the condenser, where the pump produces a pressure differential;
a working fluid transfer device downstream of the condenser and fluidly connecting to the evaporator by a capillary tube; and
a flow control device operatively disposed between the downstream end of the evaporator and the upstream end of the condenser for selectively interrupting the flow of gaseous working fluid therebetween in a timed relationship with the rate of condensation of working fluid in the condenser so as to maintain a pressure differential across the working fluid transfer device to force liquefied working fluid to the evaporator.
7. A refrigeration system in claim 6 further comprising:
a dryer which is fluidly interposed between the working fluid transfer device and the condenser for removing predetermined contaminants from the working fluid.
8. A refrigeration system in claim 6, the pump is adapted to selectively pump fluid therethrough in a timed relationship with the opening of the flow control device.