METHOD FOR CONTINUOUSLY TREATING VACUUM RESIDUALS ORIGINATING FROM THE REFINERY OF CRUDE OIL

Abstract

In a method for continuously treating vacuum residuals originating from the refinery of crude oil, the the vacuum residuals are continuously fed into an agitated vessel,

Claims

1. Method for continuously treating vacuum residuals originating from the refinery of crude oil , wherein the crude oil is subjected to a first and a second distillation step, wherein the second distillation step is performed under vacuum conditions, wherein the vacuum residuals are obtained after the second distillation step, wherein the vacuum residuals are continuously fed into an agitated vessel, the agitated vessel is a single-shaft mixer kneader, wherein the vacuum residuals are continuously fed into the single-shaft mixer kneader through at least one feed point of that single-shaft mixer kneader, wherein the shaft of the single-shaft mixer kneader is equipped with kneading elements and wherein the single-shaft mixer kneader comprises a housing which is equipped with kneading counter-elements, wherein the kneading elements and the kneading counter-elements are arranged in a co-operating fashion, wherein the housing comprises at least one vapour connection, wherein the vacuum residuals are conveyed alongside the single-shaft mixer kneader to a discharge device of the single-shaft mixer kneader, wherein the vacuum residuals in the single-shaft mixer kneader are subjected to a vacuum of 10 mbar or lower and to a temperature of at least 300 C. to remove volatiles which could not be removed by the distillation steps through the at least one vapour connection, and wherein the remaining non-volatile matter is discharged through the discharge device.

2. Method according to claim 1, wherein the shaft of the single-shaft mixer kneader is equipped with at least one mechanical seal.

3. (canceled)

4. (canceled)

5. Method according to claim 1, wherein the mixer kneader is equipped with a discharge screw.

6. (canceled)

7. Method according to claim 1, wherein a liquid agent is added which can transition into the gaseous phase in order to reduce the partial pressure of other gaseous component present in the agitated vessel.

8. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Further details and advantages oft he present invention are discussed with respect to the preferred examples presented hereafter and with respect to the figures.

[0037] FIG. 1 shows the first steps of a typical refinery process according to the state of the art at the left side and;

[0038] FIG. 2 shows in detail the treatment of the vacuum residuals according to the present invention;

[0039] FIGS. 3 and 4 show the working mechanism of a single-shaft mixer kneader according to an example of the present invention.

DETAILED DESCRIPTION

[0040] FIG. 1 shows how valuable substances are obtained by the first steps in a state-of-the-art refinery process. The left side of FIG. 1 schematically shows especially the distillation steps performed in distillation columns yielding the valuable substances as indicated in FIG. 1 above the arrows.

[0041] On the right side of FIG. 1, the gradients of molecular weight (Mw) and viscosity as well as tray efficiency is illustrated with respect to the substances obtained from the distillation step on the left side of FIG. 1. The uppermost bar on the right side in figure one refers to gases obtained from atmospheric distillation, the lowermost one refers to vacuum residuals obtained from vacuum distillation.

[0042] The bars are only illustrative. However, if inspected separately for each distillation step, they show the gradients observed when comparing the substances and intermediate products indicated on the left side.

[0043] FIG. 2 shows an example of the present invention where the vacuum residuals (cf. FIG. 1) are not directly discharged or introduced to a coker, but instead treated in a single-shaft mixer kneader 1 where an additional distillation step is performed.

[0044] The engine 2 of the single-shaft mixer kneader 1 is shown as well as the shaft 4, the double-shaft discharge screw 3 and the housing 5. Furthermore, the vapour connections 8, the feed point 9 are shown. The kneading elements 6 mounted on the shaft 4 are shown as well as the kneading counter-elements 7 mounted on the housing 5.

[0045] FIG. 3 shows an enlarged view of the single-shaft mixer kneader 1 of FIG. 2, the engine 2 is left out for the sake of simplicity. Moreover, a cross-sectional view of the single-shaft mixer kneader 1 is shown.

[0046] FIG. 4 shows the single-shaft mixer kneader 1 of FIG. 2 filled with vacuum residual which does not completely fill the inside of the housing 5.

[0047] According to an example of the present invention, vacuum residuals origination from the vacuum distillation step are introduced into the single-shaft mixer kneader 1 via feed point 9, are transported alongside the single-shaft mixer kneader 1 while being mixed by the co-operating kneading elements 6 and kneading counter-elements 7 and volatile compounds including valuable substances are removed via the vapour connections 8. The remaining matter is then discharged by the discharge screw 3. During that process, heat and vacuum is applied.

TABLE-US-00001 Reference number list 1 Single-shaft mixer kneader 2 Engine 3 Double-shaft discharge screw 4 shaft 5 Housing 6 Kneading elements 7 Kneading counter-elements 8 Vapour connection 9 Feed point 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66