METHOD AND DEVICE FOR TREATMENT OF LIQUID HYDROCARBONS

Abstract

Disclosed is a method and a device for purification and desulfurization of liquid hydrocarbons, which, compared to sodium dispersion desulfurizing processes like already been disclosed, open up additional fields of application and greatly improves economy and achievable results.

Claims

1. A device for sodium treatment of liquid hydrocarbons for the purpose of purification, desulfurization and reducing of aromatic compounds, comprising of: a heatable vessel, having in an upper part pressure-lock inlets for liquid hydrocarbons and pressure lock inlets for solid or molten metallic sodium, and in a lower region pressure lock outlets for liquids and reaction products and; having attached a pressurizable pump and dispersion circuit comprising of at least one pumping unit and at least one dispersing unit, a flow pipe connecting the dispersion unit with a re-entry into the vessel and a throttle valve located short before the re-entry into the vessel, whereby circulation of liquids through the pump and dispersing circuit can proceed in a way, that liquids first flow from the lower part of the vessel into the at least one pumping unit to be pressurized, and then flow into the at least one dispersing unit to be dispersed under pressure, and; having passed the at least one dispersing unit, flows back into the vessel through the flow pipe, in which through adjusting the pressure generated by the at least one pumping unit, adjusting the flow rate of the at least one dispersing unit, and adjusting the flow rate by means of the throttle valve located short before the return point of the liquids into the vessel, pressure and residence time of the flowing medium are controllable.

2. The device according to claim 1, wherein the pump and dispersing circuit, attached to the vessel includes a pumping unit, an afterwards attached dispersion unit and an afterwards attached flow pipe, that connects the dispersion unit with a re-entry into the vessel and whose diameter and length is chosen so, that, through adjusting the throttle valve located before the point where liquid return into the vessel a residence time for liquids in the flow pipe is settable between 2 and 300 seconds.

3. The device according to claim 2, wherein the pumping unit is electronically adjustable by a frequency converter and is able to pressurize fluids before flowing into the dispersion unit to pressure rates between 2 bar and 100 bar.

4. The device according to claim 1, wherein the pump and dispersing circuit, attached to the vessel includes a combined pumping and dispersing unit comprising of at least one pumping impeller and; at least one rotor-stator-disperger-module mounted on the same shaft and located in the same casing and; an afterwards attached flow pipe connecting this combined pump and dispersion unit with a re-entry into the vessel, whose diameter and length is chosen so, that, through setting of the throttle valve located short before the point where liquids return into the vessel a residence time for the through flowing liquid is adjustable between 2 and 300 seconds.

5. The device according to claim 4, wherein diameter and size of the pumping impeller and diameter and size of the rotor-stator-disperger-combination of the combined pump and dispersion units located in the same casing, are chosen so, that at an disperger rotor rotating speed necessary for optimal dispersion effect, then the pumping-element provides pressure between 2 and 100 bar.

6. The device according to claim 1, wherein pump-drive-e-motors and disperger-drive-e-motors are equipped with frequency converters which are connected to an electronic monitoring system, which is also monitoring the pressure in the pump and dispersing circuit and the adjustments of the throttle valve, and therewith is able to obtain, control and maintain adjustable pressure and flow rates within the pump and dispersing circuit.

7. The device according to claim 1, wherein in the moment of introducing metallic sodium, inside the pump and dispersing circuit pressure is higher than 3 bar, temperatures are above 100 C., and residence time for the through flowing liquid is adjusted to be longer than 2 seconds, to achieve purification, desulfurization and/or reduction of aromatic compounds of liquid hydrocarbons.

8. The device according to claim 1, wherein in the moment of introducing metallic sodium, inside the pump and dispersing circuit pressure is higher than 3 bar, temperatures are above 100 C., and residence time for the through flowing liquid is adjusted to be longer than 10 seconds, to achieve splitting and shortening of hydrocarbon molecular chains of oil with boiling point higher than middle distillates to turn them into those of oil in the range of middle distillates.

9. A method for treatment of liquid hydrocarbons, where purification, desulfurization and reduction of aromatic compounds of liquid hydrocarbons is achieved by circulating the liquid hydrocarbons in a device that includes a vessel having in an upper part pressure-lock inlets for liquid hydrocarbons and; pressure lock inlets for solid or molten metallic sodium, and in a lower region pressure lock outlets for liquids and reaction products, and; having attached a pressurizable pump and dispersion circuit comprising of at least one pumping unit and; at least one dispersing unit, a flow pipe connecting the dispersion unit with a re-entry into the vessel and a throttle valve located short before the re-entry into the vessel and adding metallic sodium at temperatures higher than 100 C., then passing the sodium containing liquid through a pumping unit to be pressurized to values between 1-100 bar, then passing the sodium containing pressurized liquid through a high shear disperser unit to form sodium particles of sizes below 2 microns and; simultaneously disperse those sodium particles into the hydrocarbon liquid and then pass this liquid with the mixed in sodium particles through the flow pipe connecting the dispersion unit with a re-entry into the vessel by keeping the applied pressure and adjusting a residence time in the flow pipe of at least 2 seconds.

10. The device according to claim 2, wherein the residence time for liquids in the flow pipe is settable between 40 and 80 seconds.

11. The device according to claim 3, wherein the pumping unit is able to pressurize fluids before flowing into the dispersion until to pressure rates between 10 bar and 40 bar.

12. The device according to claim 4, wherein the residence time for the through flowing liquid is adjustable between 40 and 80 seconds.

13. The device according to claim 5, wherein the pumping-element provides pressure between 10 and 40 bar.

14. The device according to claim 7, wherein the pressure inside the pump and dispersing circuit is higher than 15 bar, the temperatures are above 240 C., and the residence time for the through flowing liquid is adjusted to be longer than 15 seconds.

15. The device according to claim 7, wherein the pressure inside the pump and dispersing circuit is higher than 20 bar, the temperatures are above 280 C., and the residence time for the through flowing liquid is adjusted to be longer than 30 seconds.

16. The device according to claim 8, wherein the pressure inside the pump and dispersing circuit is higher than 15 bar, the temperatures are above 240 C., and the residence time for the through flowing liquid is adjusted to be longer than 30 seconds.

17. The device according to claim 8, wherein the pressure inside the pump and dispersing circuit is higher than 30 bar, the temperatures are above 320 C., and the residence time for the through flowing liquid is adjusted to be longer than 60 seconds.

18. The method according to claim 9, wherein the metallic sodium is added at temperatures higher than 240 C., then the sodium containing liquid is passed through the pumping unit to be pressurized to values between 5-50 bar; and wherein the residence time in the flow pipe is at least 15 seconds.

19. The method according to claim 9, wherein the metallic sodium is added at temperatures higher than 280 C., then the sodium containing liquid is passed through the pumping unit to be pressurized to values between 25-35 bar; and wherein the residence time in the flow pipe is at least 30 seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] a) FIG. 1 is a side schematic view illustrating an example of a possible embodiment of the device with individual pumping and dispersing units wherein the presentation of heaters or heat insulation is omitted.

[0079] b) FIG. 2 is a side schematic view illustrating an example of a possible embodiment of the device with a combined pumping and dispersing unit wherein the presentation of heaters or heat insulation is omitted.

[0080] c) FIG. 3 is a side view schematic view illustrating an example of a possible embodiment of a combined pumping- and dispersing unit comprising of one pumping impeller and two rotor-stator-disperger modules mounted in line on the same shaft in the same casing.

DETAILED DESCRIPTION

[0081] Referring to FIG. 1, there is shown a device for sodium treatment of liquid hydrocarbons for the purpose of purification, desulfurization and reducing of aromatic compounds.

[0082] Liquid hydrocarbons, which should be anhydrous and preferably purified from coarse impurities and non-molecularly bound impurities, have to be introduced through entry 1) in liquid state into the vessel 4).

[0083] If not, or not sufficiently heated before being filled into vessel 4), the liquids should be heated in the vessel 4) to the desired treatment temperature before the sodium input.

[0084] From the moment the liquid hydrocarbons are circulating in the device through the pumping unit 7), the dispersing unit 8), the flow pipe 10) and the throttle valve 5) and liquid temperatures higher 100 C. are reached, sodium can be introduced through input sluice 2) into the vessel 4).

[0085] If in the device sulphur reduction of less than 10 ppm and/or reduction of aromatic hydrocarbon components is desired, fluid temperatures above 280 C. should prevail before entering the sodium through input sluice 2) into the vessel 4).

[0086] The hot fluid in the device then continuously flows from the lower part of the vessel 4) through pumping unit 7) through dispersing unit 8) through flow pipe 10) and through throttle valve 5), and is subjected to strong mechanical forces, high shear and adjustable pressure before returning at entry point 12) into vessel 4).

[0087] Once sodium is introduced through the input sluice 2) into the vessel 4), it melts immediately and enters the pump-and dispersing circuit 7)8)10)5)12) through which it then flows again and again.

[0088] The minimal, stoichiometric sodium amount required in ppm is equivalent to 1.5 times the ppm of the sulphur contained in the hydrocarbon liquid, but also depends on the treatment objective and possible other ingredients that could react with sodium.

[0089] Sodium may be introduced into the device in solid or liquid state via the sodium input sluice 2), located at the upper part of the vessel 4).

[0090] The entered sodium immediately participates in the circulation through the pump- and dispersing circuit 7) 8) 10) 5) 12) and is kept from this moment, together with the oil to be treated, continuously in circulation and dispersing state throughout the entire treatment time.

[0091] If oils in the range of middle distillate, boiling on from 160 C., are treated, vessel 4) has only to be kept under pressure of 4-6 bar, what is usually enough to maintain the oils in liquid state at treatment temperature, at 280 C.

[0092] By adjusting the flow rate in the flow pipe 10) by means of the throttle valve 5) located short before liquid return point 12) at vessel 4), the pressure created by pumping unit 7) can be kept or can be adjusted to a desired value, until fluids return to the vessel 4).

[0093] Depending on treatment target and amount of sodium entered through the sodium input sluice 2) into the vessel 4), the necessary treatment time of liquid hydrocarbons in the device can amount, from the moment of sodium input, between 2 and 120 minutes, but using optimal sodium amounts and optimal pressure adjustments a treatment time between 5 and 20 minutes is sufficient.

[0094] After treatment, the oil and reaction products can leave the device through outlet 6), located at the lower part of the vessel 4), or through outlet 9), located after dispersing unit 8) in the pump- and dispersion circuit.

[0095] To separate than reaction products from the liquid hydrocarbons, the liquids can be decompressed through valve 6) or valve 9) into a settling tank, into a centrifuge, or preferably into a distillation device, whereby heat previously supplied to the treatment process, can also be used for the distillation.

[0096] In an existing test device constructed according to the explanations of this application, comprising of a vessel with 401 capacity, a pumping unit of 1 m3/h flow capacity and 20 bar of pressure capacity, a disperger unit with flow capacity of 1 m3/h and a flow pipe of 100 mm diameter and length of 3 m, it was shown as one of many examples, that after subsequent separation of the reaction products from the liquid, a 15 minutes treatment of 301 diesel fuel, with initial 2300 ppm sulfur content and initial 21.2% content of aromatics (17.8% Mono-Aromatics and 3,5 Poly-Aromatics), resulted in remaining sulfur content in the diesel below 2 ppm and in remaining total aromatic content in the diesel of only 12.9% (10.7 Mono-Aromatics and 2.2% Poly-Aromatics).

[0097] Throughout this specification and the claims which follow, unless the context requires otherwise, the word comprise, and variations such as comprises and comprising, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0098] The reference in this specification to any known matter or any prior publication is not, and should not be taken to be, an acknowledgment or admission or suggestion that the known matter or prior art publication forms part of the common general knowledge in the field to which this specification relates.

[0099] While specific examples of the invention have been described, it will be understood that the invention extends to alternative combinations of the features disclosed or evident from the disclosure provided herein.

[0100] Many and various modifications will be apparent to those skilled in the art without departing from the scope of the invention disclosed or evident from the disclosure provided herein.

Assignment of the Numbers in FIG. 1:

[0101] 1) Entry for liquid hydrocarbons to be treated [0102] 2) Input sluice for sodium in solid or liquid state [0103] 3) Sodium input sluice pressure lock [0104] 4) Vessel [0105] 5) Throttle valve to adjust flow rate in pump- and dispersing circuit [0106] 6) Outlet for treated liquids and reaction products [0107] 7) Pumping unit [0108] 8) Disperser unit [0109] 9) Additional outlet for treated liquids and reaction products [0110] 10) Flow Pipe connecting dispersion unit and re-entry point into the vessel [0111] 11) Pressure lock of entry for liquid hydrocarbons to be treated [0112] 12) Entry point of returning liquid into vessel

Assignment of the Numbers in FIG. 2:

[0113] 1) Entry for liquid hydrocarbons to be treated [0114] 2) Input sluice for sodium in solid or liquid state [0115] 3) Sodium input sluice pressure lock [0116] 4) Vessel [0117] 5) Throttle valve to adjust flow rate in pump- and dispersing circuit [0118] 6) Outlet for treated liquids and reaction products [0119] 7) Combined Pumping- and Dispersing Unit [0120] 9) Additional outlet for treated liquids and reaction products [0121] 10) Flow Pipe connecting dispersion unit and re-entry point into the vessel [0122] 11) Pressure lock of entry for liquid hydrocarbons to be treated [0123] 12) Entry point of returning liquid into vessel

Assignment of the Numbers in FIG. 3:

[0124] 1) Entry for liquid hydrocarbons and melted sodium [0125] 2) Outlet for pressurized and dispersed liquid [0126] 3) Casing [0127] 4) Pumping impeller [0128] 5) Stator of first Rotor-Stator Module [0129] 6) Rotor of first Rotor-Stator Module [0130] 7) Stator of second Rotor-Stator Module [0131] 8) Rotor of second Rotor-Stator Module [0132] 9) High Temperature sliding ring seal [0133] 10) Drive shaft [0134] 11) Bearing housing [0135] 12) Connection drive motor