EP1590423A1

EP1590423A1 - Method for high-temperature distillation of residual oil in a limited time

Info

Publication number: EP1590423A1
Application number: EP03813544A
Authority: EP
Inventors: Hans-Jürgen WEISS; Udo Zentner; Helmut Heurich
Original assignee: Lurgi Lentjes AG
Current assignee: Lurgi Lentjes AG
Priority date: 2002-12-19
Filing date: 2003-07-09
Publication date: 2005-11-02
Anticipated expiration: 2023-07-09
Also published as: DE10259450A1; ATE354625T1; WO2004056942A1; JP2006510757A; US20060138030A1; ES2282737T3; DE10259450B4; DE50306611D1; CA2511156A1; EP1590423B1; CA2511156C; AU2003250003A1; US7507330B2; AU2003250003B2; JP4365788B2; MXPA05006696A

Abstract

The invention relates to a method for a high temperature short-time distillation of residual oil. The method according to the invention is characterized by a technically simple recovery of a small residual fraction from a gas and/or oil vapour mixture produced by a mixing apparatus (1). Said small residual fraction contains large quantities of undesirable polluting catalytic substances (CCR, Ni, V, asphaltenes). For this purpose, the gas and/or oil vapour mixture produced by the mixing apparatus (1) is diluted with gas or water vapour in a column (17) at a temperature of 450° C. in such a way that a high boiling fraction, which has a high content of the pollutant substances and whose initial boiling point is higher than 450° C., is condensed and extracted. Another realization of the method consists in introducing a non condensed oil produced in the column (17) into a fractionating column (19), where said oil is decomposed in order to produce a depressurized gas oil fraction having a low content of pollutants and a benzine/gas oil fraction.

Description

Process for high-temperature short-term distillation of residual oil

description

The invention relates to a method for high-temperature short-term distillation of a residual oil from the processing of petroleum, natural bitumen or oil sand, wherein the residual oil is mixed with granular, hot coke as a heat transfer medium in a mixing plant, converted to oil vapor, gas and coke and gases and Extracts vapors from the mixer largely separately from the granular coke, cools gases and vapors and produces a product oil as condensate and gas, and that coke withdrawn from the mixer is heated again and returned to the mixer as a heat carrier.

Methods of this type are described in DE-C-19724074 and DE-A-19959587. These processes have the property that the product oil produced contains pollutants such as heavy metals (nickel, vanadium), Conradson carbon residue (CCR) and asphaltenes only in a strongly depleted concentration compared to the residue oil used. This is of great advantage for a subsequent catalytic conversion of the product oil fraction boiling above approximately 360 ° C. in a Fluidized Catalytic Cracker (FCC) to gasoline and gas oil. However, if the catalytic conversion of these heavy product oil fractions is to take place in a hydrocracker, the catalyst pollutant content must be reduced further because of its higher requirements.

Experience has shown that the remaining pollutants are enriched in the highest-boiling fraction of the product oil. A reduction of the pollutants can basically be done by a subsequent vacuum distillation of the product oil boiling above 360 ° C, in which a pollutant-containing vacuum residue (VR) and a largely pollutant-free vacuum gas oil (VGO) is obtained. A disadvantage of this method is that vacuum distillation is technically complex and is only possible up to certain boiling cut temperatures between VGO and VR in the range of approximately 500 to 560 ° C. This results in a large amount of VR containing pollutants, which can be converted in the FCC system but not in a hydrocracker. On the basis of this prior art, the object of the invention is to improve the process for the high-temperature, short-term distillation of residual oils in such a way that the smallest possible residue fraction can be obtained from the product oil in a technically simple manner, in which the undesired catalyst pollutants are largely concentrated.

According to the invention the object is achieved in that a pollutant-rich residue fraction of the vaporous product oil from the mixer after the addition of steam or gas to lower the partial pressure at temperatures below 450 ° C. is condensed in a column and taken off separately from the rest of the product oil. The uncondensed product oil vapors can then be fed from the column to a fractionation column in which the remaining low-pollutant product oil is broken down into a VGO and a gasoline / gas oil fraction.

The invention makes use of the fact that the entire product oil is in vapor form at the outlet of the mixer and can be broken down into the desired fractions by fractional condensation. To reduce the proportion of pollutant-rich VR, the boiling cut between VGO and VR must be set as high as possible in the range between 450 ° C and 650 ° C, so that the separated VR fraction more than 60% of the Conradson carbon residue still contained in the product oil vapors (CCR ), contains more than 70% of the heavy metals nickel (Ni) and vanadium (V) still contained in the product oil vapors as well as more than 80% of the asphaltenes still contained in the product oil vapors. Since condensed oil fractions would decompose or coke quickly at temperatures above 450 ° C, the partial pressure of the oil fractions to be separated is reduced by introducing water vapor or gas into the column, so that at 450 ° C a heavy condensate with a start of boiling above 450 ° C condensed. The condensation of the low-pollutant VGO (start of boiling approx. 360; boiling end 450 to 650 ° C) and the gasoline / gas oil fraction (boiling range C ₅ - up to approx. 360 ° C) can then take place in a second condensation stage at correspondingly ^' lower temperatures. The low-pollutant VGO obtained in this way can then be catalytically converted to gasoline and gas oil in a hydrocracker and the heavy condensate can either be returned to the mixing reactor or used in some other way, for example as heavy fuel oil. Design options of the method are explained using the drawing as an example. It shows

Fig. 1 is a flow diagram of the method.

In Fig. 1 is a mixing reactor (1) through the line (3) 500 ° C to 700 ° C hot heat transfer coke from the collecting bunker (2). At the same time, residual oil with a temperature of 100 ° C. to 400 ° C. is fed to the mixing reactor (1) through line (4). A conversion temperature of the mixture of 450 ° C. to 600 ° C. is established during the mixing. The heat transfer coke in the mixing reactor (1) usually has a particle size in the range from 0.1 to 4 mm, so that at the mixer outlet the coke is largely separated from the gases and oil vapors formed in the mixing unit.

The mixer (1) has at least two intermeshing screws rotating in the same direction. The screws are designed in the manner of a screw conveyor and are designed with spiral conveyor blades.

The hot, largely oil-free, granular coke leaves the mixing reactor (1) at the mixer outlet at a temperature of 450 to 600 ° C. and falls through a channel (7) into a post-degassing bunker (8), to which a stripping gas (9) is fed in the lower part can be. Residual gases and vapors can be drawn out of the post-degassing bunker (8) through the channel (7). Excess coke is withdrawn via line (2a), a part of the coke alternatively also being able to be withdrawn via lines (12a). The coke from line (12) reaches the collecting bunker (2) via a pneumatic conveyor line (10), which is supplied with combustion air via line (5) and fuel via line (6). With the conveyance upwards through the pneumatic conveying section (10), part of the coke and / or the supplied fuel is burned at the same time. The coke heated in the pneumatic conveyor section (10) reaches the collecting bunker (2), from which exhaust gas is removed through line (11). The coke in the collection bunker (2) has temperatures in the range of 500 to 700 ° C.

The gaseous and vaporous products of the mixing reactor (1) are passed through line (13) into a cyclone (14). The fine coke particles are separated off here, which are passed through line (15) into the post-degassing bunker (8).

The gaseous and vaporous products are quenched from the cyclone (14) via line (16) in a column (17) and cooled from 450 to 600 ° C to 350 to 450 ° C. Recirculated C - product gas from the container (23) or steam is introduced into the top of the column (17) via line (24a). This is the partial pressure of the vapor Product oil reduced so far that at 350 - 450 ° C a heavy oil fraction condenses with a boiling point between 450 and 650 ° C, in which almost all pollutants are concentrated. This prevents the condensed oil from decomposing or coking. The column (17) is preferably a quench cooler with a downstream multiventuri scrubber, in which the gases and vapors originating from the mixing reactor (1) are cooled very efficiently in a co-current process and residual coke dust is washed out with its own condensate. However, other apparatus can also be used for this purpose.

In order to reduce the proportion of polluting heavy oil, the boiling cut between VGO and VR is set to the highest possible temperature in the range from 450 to 650 ° C. This is done by feeding gas or steam to the top of the column (17) via line (24a) and by cooling the gases and vapors by means of cooled heavy oil condensate from line (27a). The heavy oil condensate is withdrawn at a temperature of 350-450 ° C. from the bottom of the column (17) through line (27), cooled to the required temperature in a heat exchanger (25) and partly as a cooling / washing medium at the top of the column (17) fed again. The rest of the heavy oil condensate is withdrawn as a product via line (27b). The heavy oil condensate from line (27b) can then either be returned to the mixing reactor (1) or otherwise, e.g. as a heavy fuel oil.

The uncondensed gas / oil vapor mixture is drawn off via line (18) from the lower part of the column (17). According to a further embodiment of the invention, it can be passed into a fractionation column (19). There, the remaining product oil is separated into a low-pollutant VGO and a pollutant-free gasoline / gas oil fraction. The VGO with a boiling point of 450-650 ° C. is drawn off from the bottom of the fractionation column (19) via line (21). The VGO obtained in this way can then be catalytically converted to gasoline and gas oil in a hydrocracker (not shown). From the top of the fractionation column (19), the remaining gas / oil vapor mixture is cooled via line (20) in the condenser (22) and in the container (23) into a gasoline / gas oil fraction with a boiling range of, for example, C ₅ - 360 ° C and a C ₄ . -Gas separated. The gasoline / gas oil fraction is withdrawn via line (26) and partly returned via line (26b) to the top of the fractionation column (19). The remaining gasoline / gasoil mixture is discharged as product via line (26a).

The uncondensed C ₄ . -Gas is discharged from the container (23) via line (24) upwards and partly returned via line (24a) to the column (17) and partly withdrawn as product via line (24b). example

The mixing reactor (1) is fed through line (4) 100 t / h of residual oil at a temperature of 300 ° C. 75 t / h gas / oil vapor mixture at 550 ° C. are passed from the mixing reactor (1) through line (13) into a cyclone (14) for dedusting. The remaining 25 t / h coke are passed through line (7) together with the heat transfer coke into the post-degassing bunker (8).

The gas / oil vapor mixture is passed from the cyclone (14) via line (16) into a column (17), where it is diluted with gas and cooled from 550 ° C. to 425 ° C. For this purpose, the column (17) 43 t / h of C _4- gas from line (24a) and 55 t / h of cooled heavy oil condensate from line (27a) are fed at a temperature of 380 ° C.

65 t / h of heavy oil condensate with an initial boiling point of 600 ° C. are drawn off from the bottom of the column (17) via line (27) and cooled in a heat exchanger (25) from 425 ° C. to 380 ° C. 55 t / h of cooled heavy oil condensate are then fed back to the top of the column (17) via line (27a) and 10 t / h are withdrawn as product via line (27b). From the lower part of the column (17), 108 t / h uncondensed gas / oil vapor mixture are passed via line (18) into a fractionation column (19). 40 t / h of low-pollutant VGO at a temperature of 350 ° C. are drawn off from the bottom of the fractionation column (19) via line (21). The remaining 68 t / h gas / oil vapor mixture are withdrawn from the top of the fractionation column (19) via line (20), cooled to 43 ° C. in a condenser (22), passed into the container (23) and there into a liquid petrol / gas oil fraction with a boiling range of C ₅ - 360 ° C and a C ₄ . -Gas separated. Via line (24) 53 t / h C ₄ . -Gas withdrawn and 43 t / h of this fed back via line (24a) into the top of the column (17). The remaining 10 t / h C ₄ . -Gas are withdrawn as a product via line (24b). From the container (23) 15 t / h gasoline / gasoil mixture are still withdrawn as a product via line (26a).

In a one-stage condensation according to the prior art, instead of 10 t / h heavy oil condensate with a boiling point of 600 ° C, 50 t / h residue with a boiling point of 360 ° C would be obtained. Even with a complex vacuum distillation, only 20 t / h of low-pollutant VGO with a boiling range of 360 - 510 ° C can be obtained from this residue. According to this invention, however, 40 t / h low-pollutant VGO with a boiling range of 360-600 °, i.e. double the amount to be won.

Claims

claims

1. A method for the high-temperature short-term distillation of a residue oil from the processing of petroleum, natural bitumen or oil sand, whereby the residue oil is mixed with granular, hot coke as heat transfer medium in a mixing plant (1), converted to oil vapor, gas and coke and gases and withdraws vapors from the mixer (1) largely separately from the granular coke, cools gases and vapors and produces a product oil as condensate and gas, and that coke withdrawn from the mixer (1) is heated again and transferred to the mixer (1) as a heat transfer medium recycled, characterized in that the vaporized product oil is partially condensed in a column (17) with the addition of gas or water vapor to lower the partial pressure at temperatures below 450 ° C, a high-boiling fraction is withdrawn from this column (17) and the non-condensed Gases and oil vapors are derived.

2. The method according to claim 1, characterized in that the uncondensed gases and oil vapors from the column (17) are fed to a second fractionation column (19) in which the product oil uncondensed in the first column (17) in a low-pollutant vacuum -Gas oil and is broken down into a gasoline / gas oil fraction.

3. The method according to claim 1 to 2, characterized in that self-generated recycle product gas is introduced into the column (7) as a gas.

4. The method according to claims 1 to 3, characterized in that the partial pressure of the product oil in the column (17) is reduced to such an extent that a low-boiling fraction with a start of boiling between 450 and 650 ° C condenses and separates at temperatures below 450 ° C can be deducted from the other product oil fractions.

5. The method according to claim 1 to 4, characterized in that the separated high-boiling fraction more than 60% of the Conradson carbon residue (CCR) still contained in the product oil vapors, more than 70% of the heavy metals nickel (Ni) still contained in the product oil vapors and vanadium (V) and more than 80% of the asphaltenes still contained in the product oil vapors.

6. The method according to claim 1 to 5, characterized in that before the introduction into the column (17), the gas / oil vapor mixture from the mixer (1) is dedusted in a cyclone (14).

7. The method according to claim 1 to 6, characterized in that the column (17) is designed as a quench cooler with a downstream multiventuri scrubber, in which the gases and vapors originating from the mixer are cooled and residual coke dust is washed out.

8. The method according to claim 1 to 7, characterized in that the separated in the column (17) high-boiling fraction is returned to the mixer (1).