EP1009785B1 - Method for high-temperature short-time distillation of residual oils - Google Patents

Abstract

High temperature flash distillation, for treating residual oils originating from crude oil refining, natural bitumen and/or tar sands, comprises feeding the oil to a mixer with granular hot coke, which serves as a thermal transfer medium. In mixing, 60-90% of the oil is vaporized. The non-vaporized fraction includes metal-containing asphaltenes. This fraction is further converted in the mixer, to oil vapor, gas and coke. Gases and vapor are withdrawn from the mixer, separately from the coke. The vapor phase is cooled and condensed to produce product oil. The gas itself is a further product. The coke is reheated and recycled to the mixer as the thermal transfer medium.

Description

The invention relates to a method for High temperature short term distillation of a liquid Residual oil from the processing of petroleum, natural Bitumen or oil sand, whereby the residual oil with granular, hot coke as a heat transfer medium (heat transfer coke) in one Mixer mixes, with 60 to 90 wt .-% of the residual oil be evaporated that the non-evaporated portion of the Residual oil, which contains the metal-containing asphaltenes, in Mix with the heat transfer medium in the mixer to oil vapor, gas and Converted coke and separated gases and vapors from the mixer withdraws from the granular coke, cools and cools gases and vapors Produced product oil as condensate and gas, and from which Mixer withdrawn coke heated again and as a heat carrier in the mixer returns.

A similar process is from the journal "Petroleum and Coal Natural Gas Petrochemicals / Hydrocarbon Technology "No. 42 (1989), Pages 235 to 237. It is described here that due to the special mixing mechanism with interlocking, co-rotating screws is possible, the gases and Vapors from the hot environment of the Remove the mixer and cool it down, making unwanted Cracking processes in the gas phase can be suppressed.

The object of the invention is the known method to develop further and the conditions of continuous operation improve. The aim is to maximize the yield of the product oil and its heavy metal content (nickel, vanadium), Konradson carbon (CCR) and heteroatoms (S, N) minimized become.

Starting from the procedure mentioned at the beginning, the ongate solved according to the invention in that the liquid residue with 500 to 700 ° C heat transfer coke in weight ratio from 1: 3 to 1: 30 in the mixer that mixes at least 80% by weight of the heat transfer coke Carn sizes in the range of 0.1 up to 4 mm that the mixing process on the grains of Heat transfer coke first a liquid residue film is formed in the mixer at the lowest possible Operating temperature in the range of 450 to 600 ° C and preferably 500 to 560 ° C predominantly evaporated (e.g. 60 to 90%) and that the remaining liquid residue film on the coke during a dwell time of 6 to 60 seconds to oil vapor, gas and coke is converted so that the withdrawn from the mixer Coke dry, free-flowing and largely free of liquid Ingredients is and that the gases and vapors formed after a residence time of 0.5 to 5 seconds from the mixer subtracted from.

Comparing the method of the invention with the conventional vacuum distillation, so the invention effects an increase in the equivalent boiling point of about 560 ° C approx. 700 ° C, which significantly increases the distillate yield. At the same time, the non-distillable. pollutant (heavy metals, heteroatoms, CCR) asphaltenes converted to oil, gas and coke. Here they remain Pollutants preferred in coke.

The lowest possible operating temperature in the mixer, at which of the coke just removed from the mixer is dry and free flowing, gives the best yield and Quality of the product oil.

The mixers in question for the process are e.g. B. Screw mixer, rotary tube mixer, paddle mixer, Ploughshare mixer or vibration mixer. Are well usable also mixing plants with interlocking, in the same direction rotating snails, known per se and in German Patent 12 52 623 and the corresponding US patent 3 308 219 and also described in German Patent 22 13 861 are. The interaction of the snails can affect deposits in their surfaces and in the mixer housing only form limited.

Another embodiment of this method is that the liquid residue oil while mixing with the hot Heat transfer coke through a first mixing section and then at least one second mixing section directs the mixer at the beginning of the first section hot heat transfer coke and residual oil and in the first Section gases and vapors at temperatures in the range of 450 up to 600 ° C releases that the heat transfer coke and the rest Residual oil-containing mixture from the first section The beginning of the second section is again called heat transfer coke admits and from the mixer in the first and / or second Section gases and vapors deducts. Here you can in the different mixture sections different temperatures set in the range from 450 to 600 ° C.

If you mix the residual oil with the hot heat transfer coke in at least two mixing sections, you can work in the important first section with the lowest possible temperatures, which means the removal of pollutants such as heavy metals (Ni, V), heteroatoms (S, N) and the Konradson carbon (CCR) with the coke produced and suppressed undesirable cracking processes in the gas phase. These cracking processes increase the formation of C ₄ gases and reduce the amount and quality of the C ₅ product oil.

The second mixing section begins where you go from the outside again fresh heat transfer coke in the from the first section coming coke mixture admits. By adding coke you increase the Temperature in the second section, reducing the temperature of the gases and fumes is also increased. Usually through the Adding heat transfer coke increases the temperature by 5 aimed at up to 50 ° C. This avoids the shortfall the dew point in the lines between the mixer and the Condensation device. At the same time, the coking of remaining non-volatile liquid residue components accelerates the coke at a higher temperature, causing the Coke dries faster in the mixer and therefore its Loses stickiness. This is a requirement for that Flow of the coke in the heat transfer circuit system. It is also possible to have more than two mixing sections to be provided and this is called at the beginning of each section Add coke from the outside.

Usually there are several sections in the first Mixing section 50 to 95% of the total mixer Initiate supplied hot heat transfer coke. At least 5% of hot coke is given at the beginning of the second or each another mixing section. If you were only two Mixing sections works in the mixing plant, one leads the hot Heat transfer coke mostly in the first and second section Weight ratio of 20: 1 to 1: 1 to.

It is also possible to use the second or a subsequent one Mixing a liquid residue oil supply, the differs from the residual oil of the first section. The Residual oil supplied to the second section can e.g. B. at treated at a higher temperature than the first residual oil. Such a second residue oil can also in a second Part of the mixer connected in parallel are thermally treated, which z. B. works at a higher temperature.

It can also be advantageous to use the liquid residue oil preheated to temperatures in the range of 100 to 450 ° C in the To manage the mixing plant. By preheating the viscosity of residual oil and the heat required for evaporation reduced, which makes the non-evaporable part of the residual oil reaches the desired conversion temperature faster.

Furthermore, it can be advantageous to use the liquid Residual oil still has an oxygen-free gas or vapor in it Mixer to initiate the residence time of the gases formed and reduce vapors in the mixer.

The inventive method achieves that about 80 to 95% of the heavy metals (Ni and V), about 50 to 70% of Konradson's carbon (CCR) and 30 to 70% of the heteroatoms (S and N) from the used Residual oil is removed with the coke produced and a C ₅ product oil is produced with a yield of 70 to 85% by weight from the residual oil. After separating the gasoline and possibly the kerosene and diesel fractions, this product oil is suitable for further catalytic processing.

Fig. 1:

ein Fließschema des Verfahrens,

Fig. 2:

ein Fließschmema des Verfahrens mit zwei Mischungsabschnitten im Mischwerk,

Fig. 3:

ein Fließschema des Verfahrens mit zwei Mischwerken,

Fig. 4:

einen horizontalen Schnitt nach der Linie IV-IV in Fig. 2 durch das Mischwerk in schematischer Darstellung,

Fig. 5:

einen horizontalen Schnitt durch ein Mischwerk mit konisch erweiterten Schnecken in zu Fig. 4 analoger Darstellung und

Fig. 6:

einen vertikalen Schnitt durch ein Mischwerk mit gegenläufig arbeitenden Schnecken in zu Fig. 1 analoger Darstellung.

Design possibilities of the method are explained with the aid of the drawing, whereby mixing mechanisms with intermeshing screws rotating in the same direction are used. It shows:

Fig. 1:

a flow diagram of the process,

Fig. 2:

a flow diagram of the process with two mixing sections in the mixing plant,

Fig. 3:

a flow diagram of the process with two mixing plants,

Fig. 4:

3 shows a horizontal section along the line IV-IV in FIG. 2 through the mixer in a schematic representation,

Fig. 5:

a horizontal section through a mixer with conically enlarged screws in a representation analogous to FIG. 4 and

Fig. 6:

a vertical section through a mixer with screws working in opposite directions in a representation analogous to FIG. 1.

As shown in Fig. 1, 500 to 700 ° C hot heat transfer coke from the collecting bunker (2) is fed to the mixer (1) through the line (3). At the same time, residual oil at a temperature of preferably 100 to 450 ° C. is injected through line (4). The weight ratio of coke: residual oil is in the range from 3: 1 to 30: 1, a temperature of the mixture (conversion temperature) in the range from 450 to 600 ° C. being established in the mixer. At least 80% by weight of the heat transfer coke have grain sizes in the range from 0.1 to 4 mm, and the grain size d _5c is in the range from 0.2 to 2 mm, as a result of which the coke is largely separated from the gases formed in the mixer and oil vapors at the mixer outlet.

The mixer (1) has two in the present case interlocking, co-rotating screws (8) and (9), which are shown schematically in Fig. 4. In a other version, the mixer can also three and more interlocking, co-rotating snails have, which can also be flared, compare Fig. 5. Each screw is like a screw conveyor trained and with conveying surfaces (8a) or (9a) provided (Fig. 4 and 5). The coiled conveying surfaces (8a) and (9a) have different slopes at different points on, as is shown in simplified form in FIGS. 4, 5 and 6. It it is advisable to increase the slope of the conveying area before giving up the Residual oil in the mixer lower than in the Form reaction zone of the mixer to the coke first axially into the reaction zone and then larger Slope of the conveying surfaces in the reaction zone intensely with the Mix residual oil.

As shown in Fig. 1, the hot, oil-free, leaves granular coke the mixer (1) at the end of the mixer with a Temperature of 450 to 600 ° C and falls through a channel (10) a post-degassing bunker (11), one in the lower part Strip gas (33) can be supplied. Remaining gases and vapors can go up from the bunker (11) through the channel (10) pull it off. Coke is drawn from the bunker through line (12) (11), part of the coke being passed through line (12a) or also removed from the system through line (2a). The remaining coke passes through line (12) to the bottom of one pneumatic conveyor line (15), which one through the line (16) combustion air and through line (17), if required to supply fuel. Combustion gases promote the Coke in the conveyor line (15) upwards, at the same time Part of the coke and / or the fuel supplied burned becomes. The coke heated in the conveyor section (15) enters the Collection bunker (2), from which one can exhaust gas through line (18) away. The coke in the bunker (2) has temperatures in the range of 500 to 700 ° C and usually 550 to 650 ° C.

Gases and vapors leave the mixer (1) through the channel (22) and enter the condensation (23), in which a rapid The gases and vapors are cooled. Product oil and gas become withdrawn separately through lines (35) and (34).

In Fig. 2 the mixer (1) has two mixing sections (1a) and (1b). At the beginning of the first section (1a) you do this Mixer through line (3) is called coke from the collection bunker (2) too. At the same time, the first section (1a) is passed through the line (4) residue oil. At the beginning of the second Mixing section (1b) is passed through the hot coke Line (3a) and, if desired, a second residue oil through line (4a). The in the mixing sections (1a) and (1b) gases and vapors formed are combined by the Line (22) or (22a) withdrawn from the mixer and the Condensation device (23) supplied.

In Fig. 3, two different residual oils by the Lines (4) and (4a) in two different mixers (1) and (5) abandoned and there at different, for each Residue converted to optimal temperatures. The mixer (1) 6 is equipped with pairs of screws (25) and (26), who work in opposite directions so that opposing ones Transport directions (27) and (28) result. Heat transfer coke is abandoned through lines (3) and (3a), and residual oil is supplied through lines (4) and (4a). The coke vent takes place in the middle through the channel (10) and draw gases and vapors through line (22). Otherwise, the process, such as already explained together with FIG. 1.

For example:

In an arrangement corresponding to FIG. 1, 10 t per hour of a vacuum residue formed during the distillation of crude oil are injected into the mixer (1) at 250 ° C. and mixed with 100 t / h of heat transfer coke at 600 ° C. The vacuum residue contains 20% by weight of CCR, 740 mg / kg vanadium and 120 mg / kg nickel. A temperature of 540 ° C is set in the mixing plant, at which 8.2 t / h oil vapors and gas and 1.8 t / h fresh coke are formed. The mixer has two intermeshing screws rotating in the same direction. The mixture of oil vapor and gas is withdrawn from the mixer and subjected to condensation. This is separated into 7.2 t / h product oil (C ₅₊ ) with 8.6% by weight CCR, 83 mg / kg V and 11 mg / kg Ni and 1 t / h gas (C _4- ). The heat transfer coke and the freshly formed coke on its surface are largely removed from the mixing unit free of liquid components and thus dry and free-flowing.

Claims (12)

1. A process for the high-temperature short-term distillation of a liquid residual oil from the processing of petroleum, natural bitumen or oil sand, wherein the residual oil is mixed with granular, hot coke as heat carrier agent (heat-carrier coke) in a mixing apparatus, wherein 60 to 90% by weight of the residual oil is evaporated, that the non-evaporated portion of the residual oil which contains the metal-containing asphaltenes is converted into oil vapour, gas and coke in a mixture with the heat carrier agent in the mixing apparatus, and gases and vapours are withdrawn from the mixing apparatus separately from the granular coke, gases and vapours are cooled and a product oil as condensate and also gas is produced, and wherein coke removed from the mixing apparatus is heated again and is returned into the mixing apparatus as a heat carrier agent, characterised in that the liquid residual oil is mixed with heat-carrier coke which is at a temperature of 500 to 700°C in a weight ratio of 1:3 to 1:30 in the mixing apparatus, that at least 80% by weight of the heat-carrier coke has grain sizes in the range from 0.1 to 4 mm, that by means of the mixing operation first of all a liquid residue film is formed on the grains of the heat-carrier coke, which film is predominantly evaporated in the mixing apparatus at as low as possible an operating temperature in the range of 450 to 600°C, and that the remaining liquid residue film on the coke is converted into oil vapour, gas and coke over a dwell time of 6 to 60 seconds, that the coke withdrawn from the mixing apparatus is dry, pourable and largely free of liquid constituents and that the resulting gases and vapours are withdrawn from the mixing apparatus after a dwell time of 0.5 to 5 seconds.
2. A process according to Claim 1, characterised in that a mixing apparatus with intermeshing screws rotating in the same direction is used as the mixing apparatus.
3. A process according to Claim 1 or 2, characterised in that the liquid residual oil during the mixing with the hot heat-carrier coke is passed through a first mixing section and then through at least one second mixing section, wherein hot heat-carrier coke and residual oil are fed to the mixing apparatus at the start of the first section and in the first section gases and vapours at temperatures in the range of 450 to 600°C are released, that hot heat-carrier coke is again fed to the mixture containing coke and remaining residual oil from the first section at the start of the second section and gases and vapours are withdrawn from the mixing apparatus in the first and/or second section.
4. A process according to Claim 3, characterised in that 50 to 95% of the total of hot heat-carrier coke supplied to the mixing apparatus is introduced into the first section.
5. A process according to Claim 3 or 4, characterised in that a liquid residual oil which differs from the liquid residual oil of the first section is supplied to the second or a subsequent mixing section.
6. A process according to one of Claims 1 to 5, characterised in that one or more liquid residual oils are subjected to high-temperature short-term distillation in a plurality of mixing apparatus.
7. A process according to Claim 1 or one of the following claims, characterised in that the gases and vapours withdrawn from the mixing apparatus entrain at most 25% of the heavy metals nickel and vanadium which are contained in the liquid residual oil which is introduced into the mixing apparatus.
8. A process according to Claim 1 or one of the following claims, characterised in that the liquid residual oil is introduced into the mixing apparatus at a temperature in the range from 100 to 450°C.
9. A process according to Claim 1 or one of the following claims, characterised in that an oxygen-free, gaseous or vaporous fluid is blown into the mixing apparatus.
10. A process according to Claim 2 or one of the following claims, characterised in that a mixing apparatus is used, the screws of which are conical.
11. A process according to Claim 2 or one of the following claims, characterised in that the mixing apparatus contains at least three screws.
12. A process according to Claim 2 or one of the following claims, characterised in that a mixing apparatus with screws having opposed directions of transportation is used and that hot heat-carrier coke and liquid residual oil is charged to the mixing apparatus at both ends such that the mixture of coke and residual oil is conveyed from both ends to the middle and there the coke is removed downwards.

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