SK97398A3 - Apparatus for the distillative separation of crude oil - Google Patents

Abstract

The apparatus is used for the fractionation of crude oil fed (L2) to furnaces (1, 2), connected (L3) directly or indirectly to the vaporisation section of a distillation column with bubble-cap trays. Side strippers are connected to different trays and/or a superheater. A head cooler is included. A gas turbine- (GT) generator (G) set in included, having a waste gas heat exchanger (W1), from which the crude is directly and/or indirectly heated.

Description

Technical field

The subject of the invention is a device for continuous distillation of crude oil by means of a distillation tower.

BACKGROUND OF THE INVENTION

Particularly important in the distillation separation of oil is its uniform heating. On the one hand, it is necessary to ensure that the oil is heated evenly, while at the same time the residence time in the heating gear for heating from, for example, 20 ° C to 360 ° C to 400 ° C must be as short as possible to prevent decomposition of crude oil. Therefore, it is envisaged to use tube furnaces with, for example, a movable grate furnace - if solid fuels - or oil or gas nozzles are used. The pipe system through which the oil is conducted is heated by the furnace heating gases.

In order to ensure gentle oil heating, so-called indirect arc furnaces are used in which the oil pipe system is located in chambers separate from the burner, and so, for example, oil can heat up slowly in the lower part and the upper heating part quickly to minimize carbonization.

In addition to tube furnaces, standing cylindrical furnaces are also known which have a perpendicular cylindrical combustion chamber wrapped in circularly arranged standing pipes. At the bottom of the cylindrical furnace there are nozzle burners for gas heating, on the other hand there is a cone in the upper part, which ensures uniform heat transfer from the gas to the pipe system.

In addition to the most uniform heat transfer, the most efficient use of heat is of great importance. When compiling the energy balance in an oil processing company, it is necessary to calculate for energy consumption using approximately 5% of processed crude oil for thermal energy. Therefore, great attention is paid to the recovery and recovery of waste heat. The waste heat from the individual fractions is used to preheat the air, for example for combustion furnaces or also to preheat other fractions. Waste heat is also used for steam production in the refinery as well as for district heating.

In order to reduce the consumption of oil or its heat-supply products within an oil refinery, various heat sources are proposed (13th World Oil Congress, Buenos Aires 1991, Proceedings V3, pp. 297 to 301). Thus, there has been a general proposal to utilize the heat of an unrealized gas-cooled high-temperature nuclear reactor, to use solar energy that requires too high investment costs, and to utilize the waste heat of gas turbines, which have to be shut down at short intervals for maintenance.

It is an object of the present invention to provide a continuous oil distillation plant in which oil can be heated gently and evenly even with different heat consumption up to a temperature of between 350 ^° C and 400 ^° C, while simultaneously saving electricity and waste heat may be diverted for further use.

The use of gas turbines in oil distillation separation has the drawback that gas turbines require maintenance at frequent multi-month intervals, and continuous distillation oil separation equipment must be operated continuously for several years to ensure the necessary economic efficiency. Even minimal changes require a difficult adjustment procedure to meet the required product composition. Even when using new oil in a distillation tower, the distillation process in the tower needs to be reset, and the temperature of the incoming oil, the amount of reflux in the distillation tower and the like must be precisely defined and controlled. During the regulation process, which lasts four to six hours, products are obtained which must be fed to the re-separation in order to achieve the required quality standard. If the distillation tower is restored, this requires an even more demanding process, which for example has long been refused by blast furnaces.

SUMMARY OF THE INVENTION

The novelty of a continuous oil distillation separator which is led through a pipeline to at least one predominantly gas-fired furnace which is connected indirectly or indirectly through a pipeline. directly with the distillation tower distillation zone with the column bottoms, in particular the bell bottoms, with strippers which are connected to at least two different extraction bottoms and to a device for producing and / or superheating water vapor and a cooler, according to the invention essentially consists in that it comprises a gas turbine connected to a jet generator with an oil-to-oil heat exchanger through which oil can be heated directly and / or indirectly.

By using the furnace in addition to the gas turbine, the distillation of the oil can be continued in the maintenance work on the gas turbine, whereby the different heat demand can be controlled by controlling the furnace heating power and thereby ensuring even gas turbine performance.

When utilizing such a high gas turbine waste heat potential, care must be taken to minimize the flow resistance of the waste gas in the heat exchanger so as not to decrease the electric power of the gas turbine, whereby relatively large areas along which heat exchange takes place. In addition to these general conditions, which require sophisticated heat exchangers, the furnace capacity must be so large that it can heat the oil to the desired temperature without additional heating by means of a gas turbine. Instead of a single furnace, for example, two or more furnaces may be used in order to achieve a better degree of efficiency at minimum heating outputs. These furnaces may have the same heating, for example gas. However, it is also possible to use fuels other than oils, a solid fuel which can also be combusted in a fluidized bed furnace.

If the waste gas heat exchanger is connected via a fluid heat transfer medium line to another oil heat exchanger, particularly gentle oil heating can be achieved, since the highest temperatures that occur in the flue gas are by no means diverted to crude oil. Furthermore, it can be achieved that the waste heat of the gas turbine is used not only for heating oil but also for other purposes.

If the waste gas heat exchanger and / or other heat exchangers are connected in series with the furnace (s), the same temperature of the oil entering the distillation tower can be ensured without additional equipment such as mixing equipment in which the oil from the mixing equipment or the oil is mixed. furnace mixes. This saves equipment while ensuring an optimal process.

If, with respect to the waste gases, an additional fuel-feed combustion apparatus is connected to the gas turbine, additional heating of the waste gases can be achieved and the proportion of oxygen still present in the waste gases can be burned, thereby achieving greater safety in waste gas handling, for example in direct oil heating.

If a waste gas heat exchanger and / or another heat exchanger is installed upstream of the at least one furnace, a particularly gentle oil heating can be achieved, since an increase in the thermal potential to the desired value can be achieved in an furnace which the heat exchanger is not subject to the limitations of the gas turbine heat exchanger. Furthermore, it can be avoided or prevented. minimize the carbonization of oil.

If at least one water heater and / or water vapor production and / or superheat system is connected to the inlet and outlet of the fluid heat transfer medium of the waste gas heat exchanger by pipeline, the waste heat from the gas turbine may be used to produce hot water or steam , such as stripers.

If the oil temperature sensor is in front of the furnace, for example, in a waste gas heat exchanger and / or in another heat exchanger, which controls or disables the heat exchanger. regulates the fuel supply of the furnace and / or other combustion equipment, the gas turbine power can be kept at a desired level in a very simple way, as there is no need to adapt to different heat consumption of different types of oil, different viscosity and flow resistance and different flow rate in the heat exchanger but a further heat exchanger in the furnace, respectively. It is very easy to control or to operate another combustion device. control.

If there is a sensor for measuring the temperature through which it is controlled, resp. regulating the fuel feed to the furnace and / or other combustion equipment intended for the oil leaving the furnace; control of the heating power of the furnace and / or other combustion equipment directly by the oil outlet temperature.

In the following, the invention will be explained in more detail by means of the figures in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 Oil heating scheme a

Fig. 2 Schematic representation of a distillation tower with sub-aggregates

DETAILED DESCRIPTION OF THE INVENTION

The gas turbine GT shown in FIG. 1 with an output of 3,000, respectively. 3.600 rpm is mechanically coupled to the current generator G. The gas turbine consumes 7.500 m ³ / h of natural gas. It is an aeroderiative turbine, such as the LM 2500+ General Electric or the DLE 2500+ General Electric with minimum nitrogen oxide emissions. The generator delivers 30,000 kW. The gases leaving the 510 ° C gas turbine enter another NB combustion plant in which the remaining oxygen content is injected with the injected natural gas (arrow a). The gases coming from the next combustion plant have a temperature of 700 ° C. In the waste gas heat exchanger Wi, the waste gases transfer their temperature to the fluidized heat transfer medium and to the diphenyl (up to 350 ° C). The fluidized heat transfer medium in line w connects the waste gas heat exchanger W _t with another heat exchanger Wa. In another heat exchanger W? the oil at 140 ° C is fed through line L _{t and is} passed via the line La at 250 ° C to the gas furnace 1, 2, in which it is further heated to 370 ° C. Another heat exchanger Wa and the furnace 1,2 are connected in series. The pipe w may also lead to a steam production device D in which steam is produced for the stripping process. In order to utilize the waste heat, the flue gases from the exchanger W1 are fed to the exchanger W3, in which the district heating water is heated. The flue gases from the gas furnace 1,2 are cooled through a heat exchanger W ₄ and the heat is used for process steam within the refinery. The flue gas temperature is maintained above 100 ° C so that condensation does not occur in the chimney. The oil heated to 370 ° C is passed through the conduit 13 to the distillation tower.

In the pipe Lg connecting the other heat exchanger W2 with the furnace 1,2 there is a temperature measuring sensor Ti, which regulates the flow of the valve Vi for the furnace gas 1,2 but also the fuel supply - arrow a - to another combustion device NB. In the outlet pipe L ₃ is positioned further sensor for measuring the temperature T2, which provides control flow valve Vg, which also can manage and regulate gas supply to the furnace, but the supply of fuel to another combustion plant, thus thus the heat output.

The distillation process is described in more detail on the basis of FIG. 2 as follows:

The oil enters from the furnace 1 and 2 in line U to the stripping column 3, in which steam is fed according to arrow X1. Further, a portion of the product is fed to the stripper column 3 (arrow L) from the bottom (sludge bed) of the distillation tower 4. The oil supplied via line L3 is heated by the waste heat of the gas turbine and the furnace 1.2 to 370 ° C. In stripping column 3 the oil pressure drops from 5 to 3 bar and then passes through line X ₂ to the firing zone of the distillation tower 4. the pressure drops to 1.5 bar. In the distillation tower 4 there are 45 bell floors. In strippers 5, 6 and 7, products withdrawn from the distillation tower are fed in and blown with steam through the pipes D 1, P ₂ and D g, thereby desorbed lighter volatile particles. At the bottom of the stripper, the material obtained is withdrawn while the products of the top of the column are re-fed. The steam to be used in the strippers was obtained by heat of the flue gas of the gas turbine in the steam production plant D (Fig. 1). The end product obtained from the strippers is cooled by heat exchangers Ws. Wg and W ₇ and the heat thus obtained is reused. Distillation tower 4 also has coolers.

Industrial usability

The invention is intended for use in oil refineries.

Claims (8)

PATENT CLAIMS 1. Installations for the continuous distillation of crude oil which is fed via a duct to at least one gas-fired furnace which is connected, via a duct, directly or indirectly, to the firing zone of the distillation tower with receiving bottoms, in particular outside walls, with traces connected to at least two various receiving bottoms and at least one device for producing and / or superheating steam with an upper cooler, characterized in that it comprises a gas turbine (GT) which is connected to a current generator (G) and is equipped with a waste gas heat exchanger (Wi) for oil for direct and / or indirect heating of oil. Apparatus according to claim 1, characterized in that the waste gas heat exchanger (W0) is a fluid heat transfer fluid line (w) connected to another oil heat exchanger (W ₂ ). Device according to claim 1 or 2, characterized in that the heat exchanger (Wi) and / or another heat exchanger (W ₂ ) is connected in series to the furnace (1, 2). Apparatus according to claim 1, 2 or 3, characterized in that a further combustion device (NB) with a fuel supply (a) to the flue gas is connected to the gas turbine (GT) - with respect to the flue gas. Apparatus according to one of Claims 1 to 4, characterized in that a heat exchanger (Wi) and / or other heat exchangers (W ₂ ) are arranged at least one furnace (1, 2) in the direction of the oil flow. Apparatus according to one of Claims 1 to 5, characterized in that the at least one water heating device and / or the steam production and / or superheat device (D) is connected via a conduit (w) to the inlet and outlet for the heat exchanger fluid heat transfer medium. waste gas heat (Wi). Apparatus according to one of claims 1 to 6, characterized in that the oil temperature sensor (T1) is in front of the furnace (1,2) in the waste gas heat exchanger (W-ι) and / or another heat exchanger (W _2). ), through which the fuel supply to the furnace (1,2) and / or to another combustion plant (NB) is controlled and / or regulated. Apparatus according to one of claims 1 to 7, characterized in that a sensor (T ₂ ) for measuring the temperature of the oil leaving the furnace (1, 2) through which the fuel supply to the furnace (1) is controlled and / or regulated. , 2) and / or to another combustion plant (NB).