WO2014195110A1

WO2014195110A1 - System and method for processing water

Info

Publication number: WO2014195110A1
Application number: PCT/EP2014/060040
Authority: WO
Inventors: Vladimir Danov; Thomas Hammer; Jochen SCHÄFER; Martin Tackenberg
Original assignee: Siemens Aktiengesellschaft
Priority date: 2013-06-05
Filing date: 2014-05-16
Publication date: 2014-12-11
Also published as: DE102013210425A1

Abstract

The invention relates to a system (1) for processing polluted water that accumulates during the extraction of a fossil fuel and contains geothermal energy. In order to separate the pollutants from the product water to be obtained from the water, at least one separating device comprising at least one evaporator (12) and at least one condenser (11) is provided. The water having the pollutants can be conducted via the at least one evaporator (12) and the at least one condenser (11) in a circuit. At least one heat exchanger (5), into which the water containing the geothermal energy can be introduced as a heating medium, is associated with the at least one separating device. By means of the at least one heat exchanger (5), at least a part of the geothermal energy can be transferred to the water having pollutants, which water can be supplied to the at least one evaporator (12). The invention further relates to a method for processing water.

Description

description

System and method for treating water The invention relates to a plant for treating What ^¬ ser, which is obtained in the promotion of a fossil fuel, has contains impurities and geothermal energy. The plant comprises at least one separating device for separating contaminants from product water to be recovered from the water. Furthermore, the invention relates to a method for treating water.

In the development of fossil fuels such as gas and oil resources, there is a trend towards the exploitation of ever lower sources due to the limited number of easily accessible sources. Similarly, sources of fossil fuel at depths, sometimes exceeding 3,000 meters, can be tapped to extract the fossil fuels contained in such sources. The extracted material consists of a mixture of oil, gas, water and solids, with an increase of the water content generally occurring as the depth of the source increases.

There is also a trend to squeeze water into oil-bearing strata from older but depleted sources and to extract a corresponding mixture of water and oil to increase the yield of such sources. The case funded mixture consists of oil, gas, the be ^¬ already contained in the layers as well as the previously pressed-water and solids. Overall, with increasing exploitation of the declining sources, the water-to-petroleum ratio continues to increase, from values currently ranging from 1 to 2, to levels of around 3. For economical and environmentally sound use of the subsidized mixtures allow these are separated into their Be ^¬ constituents. The petroleum and gas are sent for further processing. Solids and water are however, at least be disposed of in an environmentally friendly, preferred to use per ^¬ yet economical.

At the same time, it is desirable to provide high quality product water for the exploitation of the dwindling sources of fossil fuels.

Plants are known from the prior art in which the separation of a mixture consisting of petroleum, gas, water and solids, ie the treatment of the resulting in the production of fossil fuels water via two sequentially arranged separators. The Separa ^¬ tors can differentiate here in terms of the prevailing pressure and the present temperature. Usually the majority of the water is separated in a high-pressure separator at a pressure of 50 bar. In subsequent sequent ^¬ low pressure separator nearly the entire remaining 2% of the water present in the mixture to be separated bar at around 10 degrees.

However, the separated water usually contains more residual oil, salts, and smaller amounts solids in concentra ^¬ tions, which do not allow for environmentally friendly disposal. Even for a direct reuse of this water, the quality is usually not enough. For Aufarbei ^¬ processing of this water, for instance for further use in oil production, therefore consuming, multi-step separation method are used, which lent the separation of remaining solids and fine oil droplets as well enable desalting. As a separation process, for example, me ^¬ chanic filter method for the separation of solids, an electrostatic oil separation and as a final step for desalination the reverse osmosis are used. Such a known from the prior art system for processing the water used in the promotion of fossil fuels is the ^{¬ this} multi-stage cleaning, electrical energy costs due to the high complexity and the maintenance costs disadvantageous. For example, a re ^¬ gelmäßiger replacing the membrane used in the reverse osmosis system is required, resulting in high costs. Furthermore, the DE 10 2008 051 731 Al a plant for separating dissolved in a liquid foreign substances, in which the fluid flows successively through a series of Ver ^¬ dunstern, in which a carrier gas is introduced countercurrently describes. Evaporated liquid-transported to sigkeit capacitors via the carrier gas, in which the Trä ^¬ gergas is cooled. Resulting condensate is removed as product water. The liquid supplied to the evaporators is heated in a heat exchanger, to which a heated in a device heat transfer fluid is supplied. The cooled heat transfer fluid is used in the - also successively flowed through - capacitors as a cooling medium for the carrier gas.

Such a system is relatively energy consuming.

Object of the present invention is therefore to provide a system of the type mentioned above and a method for treating water, which or which allows recovery of product water in a particularly favorable manner.

This object is achieved by a system having the features of patent claim 1 and by a method having the features of patent claim 16. Advantageous embodiments with expedient developments of the invention are specified in the dependent claims.

In the system according to the invention, the at least one separating device comprises at least one evaporator and at least one capacitor. About the at least one evaporator and the at least one condenser, the impurities having water can be performed in a circuit. The ^¬ we nigstens a separation means is at least one heat exchangers associated shear, in which the geothermal energy containing water is introduced as a heating medium. Using the at least one heat exchanger is at least a portion of the geothermal energy to the at least one encryption dunster suppliable and the impurities having What ^¬ ser transferable.

This is based on the recognition that the polluted water produced by the extraction of fossil fuel usually has a high heat content. Especially in low-lying sources, where the proportion of water in the promoted Good is particularly high, the geothermally induced specific heat content of the contaminated water is also particularly high. This heat content can be used in the evaporator to heat a gaseous medium introduced into the evaporator. The heated gaseous medium can then absorb a particularly large amount of water vapor, which can be separated after the subsequent condensation process in the at least one condenser as product water.

The waste heat of the contaminated water itself is thus used as a heat source for the evaporation process. For this purpose, the at least one heat exchanger transmits geothermal energy to the contaminated water before it enters the at least one evaporator. It can be dispensed with an external heating energy source. This makes the system particularly energy-efficient and enables the extraction of product water in a particularly favorable manner. Also may be subjected to at least one evaporation and Rekondensationszyklus un ^¬ so virtually all of the contaminated water. Thus, it is possible to recover almost 100% of the water content contained in the contaminated water as product water. This clean product water or process water can then, for example, again for the

Oil extraction can be used. However, a different use as process water or environmentally friendly disposal is readily possible. Preferably, the at least one evaporator has a first inlet for the contaminated water. Here, a gaseous medium can be introduced via a second inlet of the evaporator, which is designed to receive water vapor originating from the contaminated water. The Verdunster preferably has at least one outlet through which the water vapor laden with the gaseous ^¬ Me dium can be discharged from the Verdunster. The loaded medium can be introduced into the at least one condenser, which serves to transfer the water vapor contained in the gaseous medium into the product water. As can be readily separated from the contaminated water, the product ^¬ water.

As gaseous medium for receiving the water vapor originating from the contaminated water, in particular a gas or gas mixture is suitable, which behaves inertly in the working area of the plant characterized by a temperature interval and by a pressure interval, i. in particular, neither appreciably chemically reacted nor condensed.

The gaseous medium, which receives in the at least one Ver ^¬ darkest water vapor, transported to the at least one condenser and emits there by condensation, ambient air can include or be. It comes beispielswei ^¬ se ambient air for use as this is cost effective to Ver ^¬ addition. Ambient air can be saturated well with the water vapor originating from the contaminated water. In addition, from the enriched with water vapor ambient air in the at least one condenser, the water vapor can be converted by condensation into the product water well.

The gaseous medium which receives in the at least one Ver ^¬ dunster water vapor, transported to the at least one capacitor and there emits by condensation, may also include or be an inert gas. For example, therefore, the use of an inert gas such as nitrogen is possible as gasförmi ^¬ ges medium for receiving the water vapor. The contaminated water or mixture which the at least one Evaporator is supplied, namely usually contains gas with combustible components. By using the inert gas as a gaseous medium for receiving the water vapor, however, the formation of an explosive mixture can be avoided. This makes the system particularly operation ^¬ sure.

When the inert gas is used as the gaseous medium used, are preferably devices for gas-tight Verschlie ^¬ SEN of the plant and / or for evacuating the installation and / or for the storage or generation of the inert gas and / or for introducing the inert gas into the at least one Trenneinrich ^¬ provided for. This serves the process-safe handling of the inert gas.

Preferably, the first inlet for the contaminated water and the second inlet for the gaseous medium are arranged on the at least one evaporator such that the water and the gaseous medium flow through the evaporator in countercurrent. Then, a good transition of the water vapor from the contaminated water is allowed in the medium. Thus, a convective-driven or convective-supported evaporation of the water is well feasible.

The water can be supplied via the first inlet in particular a Verrieselungseinrichtung or the like water distributor, over which can be wetted by the medium umströmbare arranged in the evaporator structures with the contaminated water. Thus, a particularly good distribution of the contaminated water can be ensured in the evaporator.

In a further advantageous embodiment of the invention, the at least one evaporator has a further outlet, which is coupled via a connecting line with the at least one capacitor. Via the connecting line, by the gaseous medium from the cooled water to a minimum ^¬ Verdunster the at least one capacitor fed, wherein the cooled water is used to liquefy the water vapor. Thus, this cooled residual water ei ^¬ ner further use can be supplied, namely a use as a cooling medium for liquefying the water vapor. This is particularly favorable from the point of view of the process.

It has been found to be advantageous in this case if a cooling device is arranged at least in the United ^¬ connecting line. If this cooling device used, so the Ver ^¬ liquid of the water vapor in the condenser takes place particularly weitge ^¬ basis, since then particularly cool (residual) is water for condensing the water vapor to the capacitor is available.

As a further advantage, it has been shown that the system has a supply line through which the water used for liquefying the water vapor in the at least one capacitor ^¬ set in the at least one evaporator is traceable. When condensing the water vapor namely the water used for this purpose is heated. Through this heat absorption of the water used for cooling purposes, an internal heat recovery can be realized, which is particularly beneficial to the energy efficiency of the system. Namely, if this heated by internal heat recovery water is again supplied to the evaporator, then in turn comparatively ^¬ much steam can be transferred to the cool in relation to the water ^¬ re medium, so the medium are particularly well loaded with water vapor.

Preferably, the feed conduit to a junction Steep over which the capacitor from the one coming water is introduced, the impurities having to and ^¬ least a Verdunster water to be supplied into the at least. At this confluence so the contaminated water and the used for cooling purposes in the condenser residual water are mixed. So the polluted water can be more ^¬ again fed to the Verdunster and so special largely recycled. In addition, the mixing brings about an increase in the temperature of the water supplied to the evaporator, if the contaminated water is warmer than the water coming from the condenser. By this mixing, a direct heat transfer can be realized without the need for another heat exchanger needs to be provided.

One is anxious comparatively large amount of product water to ge ^¬ winnen to separate at least about 80 to 90% of the water contained in the contaminated mixture, a high heat content of the water supplied to the Verdunster is advantageous. Such a high heat content can be achieved in particular by the admixing of comparatively hot, impurities exhibiting water in the water coming from the condenser. In particular, when the contaminated water having temperatures of less than 100 ° Celsius, the water can be supplied to the Ver ^¬ dunster directly. Such a design of the system is particularly simple. However, if the temperature is significantly less than 100 ° Celsius, so the encryption can be connected upstream dunster a heater so mög ^¬ lichst much product water from the contaminated water can be recovered.

However, if the contaminated water has temperatures of more than 100 ° Celsius, sudden boiling processes can lead to pressure surges when depressurised. In order to avoid damage to parts of the system in the presence of such, ie comparatively hot water, it has proven to be advantageous if, by means of the at least one heat exchanger, a temperature of the impurities having the impurities and to be fed to the at least one evaporator can be reduced, and is preferably preferred to temperatures below the boiling point of the contaminated water. So read ^¬ sen by pressure surges of boiling water related Schä- avoid on the system.

It has proven to be advantageous if the supply ^¬ line over which the evaporator with the condensate from the coming contaminated water is acted upon, is passed through the at least one heat exchanger. Then, by means of the heat exchanger, the temperature of the contaminated water is lowered to an uncritical value, namely to a value below the boiling point at the working pressure of the plant. At the same time, the water coming from the condenser is heated up by the heat transfer taking place in the heat exchanger. The then high heat content of the supplied via the supply line to the evaporator contaminated water allows a particularly high recovery rate, ie the recovery of a particularly large amount of product water.

It has also proven to be advantageous if the system comprises at least two separating devices with a respective evaporator and a respective condenser, wherein the evaporators and the condensers are each arranged to flow through the system in succession. By such a multi-stage structure of the system, the existing in the contaminated water (geo) thermal energy can be used in a particularly large extent, without sacrificing efficiency must be taken ^¬ degree. Compared to a single-stage system in fact can each lower tempera ^¬ turdifferenzen between the Verdunster and the capacitor in the individual separators or separation steps ren realization. While in a very large temperature difference, the internal heat recovery is relatively inefficient and thus ultimately supplied with the water heat is used Unzu ^¬ reaching, can be at low Temperaturdif ^¬ preferences of the existing difference of the heat content Particularly use effectively. This can generate a high amount Produktwas ^¬ ser because of cu ^¬ engined exergy losses with the present in contaminated water (geo) thermal energy. Here, it has proven to be advantageous if upstream ^¬ Windwärts of each evaporator of the at least two separation ^¬ means each one of the heat exchanger is arranged. This will ensure that a sufficiently large Temperature gradient between the contaminated water and a medium for receiving the originating from the contaminated water vapor is present. Additionally or alternatively, a respective cooling device may be arranged upstream of the respective capacitors of the at least two separation devices. Such pre-cooling - or arranged in between two capacitors cooling device intercooling - ensures particularly is nearly independent of the transfer of the water vapor in the liquid Produktwas ^¬ ser.

In a further advantageous embodiment of the invention, at least one pressure reducer upstream of an inlet of the water having the impurities into the at least one evaporator, by means of which the pressure of the water to be introduced into the at least one evaporator can be reduced. The pressure reduction takes place in an advantageous manner after cooling the water to be supplied to temperatures below the boiling point in the system. This makes the system particularly robust and reliable, as suddenly occurring boiling processes are avoided.

In this case, it has proven to be advantageous if the at least one pressure reducer is designed as a device for obtaining mechanical and / or electrical energy. Namely, it can come about, instead of a pressure regulating valve as pressure Minde ^¬ rer, for example, a turbine is used, which provides mechanical energy. This mechanical energy can be used, for example, for driving pumps or blowers, which can be used for conveying the water and / or the medium. However, the mechanical energy can also be converted into electrical energy and thus the electrical energy in the plant itself or otherwise used. This also contributes to the particularly high energy efficiency of the system. It is furthermore advantageous if there is pressure in the at least one evaporator and / or in the at least one condenser which is equal to a pressure in the vicinity of the system. By operating the system at atmospheric pressure, the construction of the system becomes more cost-effective than in the case of a system operated with overpressure or underpressure.

Finally, it has shown to be advantageous if the on ^¬ location comprises at least one upstream of the at least one Ver ^¬ dunsters arranged filter means for pre-cleaning of the impurities comprising water. This is because the contaminated water can be handled particularly well in the system. In addition, located on the output side of such a filter device, the water having the contaminants usually having a comparatively high pressure and a relatively high temperature before, so that its heat ^¬ energy for the evaporation process in the one we can Verdunster ^¬ nigstens be used particularly well.

As a filter device, in particular a Hochdrucksepara ^¬ tor can be used, which allows a separation of a large part of the water from the funded, fossil fuels, water and solids containing and geothermally heated mixture.

In the method according to the invention for the treatment of water produced during the production of a fossil fuel and containing polluted and geothermal energy, impurities are separated from the water by means of at least one separating device. In this way, product ^¬ water is obtained. The water having the impurities is circulated in the at least one separating device via at least one evaporator and at least one condenser. The at least one separation device is associated with a heat exchanger at least, in which the water-containing geothermal energy is placed as the heating medium a ^¬. By means of the at least one heat exchanger At least a portion of the geothermal energy is transferred to the water supplied to the at least one evaporator and containing the contaminants. By such evaporation and condensation process that uses the heat of the contaminated water, can win clean product water on particularly Güns ^¬ term way.

Preferably, the at least one evaporator and / or the at least one condenser are operated at a temperature which is lower than the boiling point of water at the pressure prevailing in the at least one evaporator and / or in the at least one condenser. This makes the process particularly low-effort and at the same time energy-efficient. Finally, it has proved advantageous if the po ^¬ tentielle energy of the resulting high-pressure water in the system for the operation of gaseous or liquid media promoting auxiliary equipment is used. This brings a ^high energy efficiency of the system with it.

The advantages and preferred embodiments described for the system according to the invention also apply to the method according to the invention and vice versa. The features mentioned above in the description and

Combinations of features and listed below in the Figurenbe ^¬ letters and / or alone shown in the figures features and feature combinations are possible, without departing from the scope of the invention not only in the respectively specified combination but also in other combinations combinations or alone.

Further advantages, features and details of the invention ^¬ be gathered from the claims, the following description of preferred embodiments and are in which functionally identical elements are provided with identical reference signs ^¬ reference to the drawings. Showing: 1 shows schematically a first variant of a system for

Treatment of water, which is obtained in the production of oil or gas, the system comprising a evaporator and a condenser;

2 schematically shows a second variant of the system according to

FIG. 1; a further variant of the system according to FIG 1, in which as a pressure reducer a turbine comes to Einsat; and schematically another variant of the system, in which the treatment of the water follows in several stages.

A system 1 shown schematically in FIG 1 is used for stor ^¬ ride of water which is obtained in the oil and gas production. In particular, from low-lying sources, a mixture is conveyed which comprises oil, gas, a generally increasing depth of water and solids. In addition, this contaminated water has a geothermally increasing specific heat content with increasing depth. In addition, for conveying oil or gas from a source layers, which runs out, pressed into the water ^¬ se layers and then correspondingly promoted a mixture which holds a further increased amount of water ^¬ ent. Such a geothermally heated mixture from a deep or depleted source is fed via a feed line 2 to a filter device in the form of a separator 3 of the system 1.

The separator 3 is presently designed as a high-pressure separator and is preferably operated at a pressure of about 50 bar be. About the separator 3 can already be separated abge a large part of the pressed-in water in the ground from the mixture. However, this also contains this separated water nor impurities in the form of oil residues, salts, solids and the like.

Therefore, this contaminated water is fed in Appendix 1 to a further treatment. Here, the geothermal energy of the subsidized mixture is used. This is even more meaningful because the pumped from great depths mixture usually holds geothermal energy to a considerable extent ent ^¬.

In the present case, the contaminated water coming from the separator 3 is fed to a heat exchanger 5 via a line 4. In the heat exchanger 5, this wastewater of the separator 3 releases heat, and moreover, due to the pressure loss occurring in the heat exchanger 5, the water is released. At a downstream of the heat exchanger 5 arranged valve 6, which is present example as a three-way valve Darge ^¬ represents, the cooled water in the heat exchanger 5 via a further line 7 a pressure reducer 8 is supplied. The further relaxed at the pressure reducer 8 water is introduced at a junction 9 in a feed line 10, which leads from a condenser 11 of the system 1 to a evaporator 12 of the system 1. The evaporator 12 and the condenser 11 are components of a thermal separator of the system 1. In the evaporator 12 as well as in the condenser 11 prevails in the present case preferably atmospheric pressure.

In the system 1 shown in FIG. 1, the supply line 10 is passed through the heat exchanger 5. At the heat exchanger 5, therefore, the contaminated water is cooled and at the same time the water coming from the condenser 11 is heated. About the supply line 10, the cooled, relaxed and Verunreini ^¬ tions having water, which comes from the separator 3 and which was mixed with the coming of the condenser 11 water and heated at the heat exchanger 5, introduced into the evaporator 12. For this purpose, the evaporator 12 has an inlet 13, from which the water heated in the heat exchanger 5 passes to a water distributor 14, which is arranged in the evaporator 12. About the water manifold 14 are preferably arranged in the evaporator 12 structures 15, which may be formed as a grid, for example, sprinkled with the heated water. Via a further inlet 16 provided at the evaporator 12, air is introduced into the evaporator 12, which is colder than the water introduced via the inlet 13. This air flows through the evaporator 12 in countercurrent to the emerging from the water manifold 14 water, ie in the direction opposite to the water.

The air is heated up and part of the polluted water evaporates into the opposite flowing, heating air. By heating the air, this is able to absorb more water vapor. The air enriched with the water vapor is then fed via a Lei ^¬ tion 17, which is connected via a further outlet 44 of the evaporator 12 to the evaporator 12, the condenser 11, which is colder than the evaporator 12. Condensed in the condenser 11 then much of the water vapor. Product water obtained by liquefying or condensing the water vapor is removed from the condenser 11 of the system 1 via a line 18. For cooling the water vapor in the condenser 11, the residual water not converted into water vapor is used in the present case, which is withdrawn from the evaporator 12 via a water outlet 19. This residual ^¬ water, as exemplified herein, via another valve 20, which may be formed, for example, as a three-way valve, get into a connecting line 21 through which the evaporator 12 is fluidically connected to the capacitor 11.

In this connection line 21, a pump 22 and an (optional) cooler 23 are presently arranged. Through the radiator 23, the temperature of the water flowing through the connecting line 21 to the condenser 11, used as a cooling medium water can be further reduced. Consequently, the water vapor can be converted into liquid water in the condenser 11 particularly well. The cooler 23 can be acted upon via a further line 24 with a cooling medium, for example with cooling water.

Via the valve 20, a partial flow can be branched off from the water leaving the evaporator 12, which partial flow is contaminated comparatively strongly with concentrated impurities. This branching of water to be disposed of can take place via a further line 25. For energizing the vaporizer 12 with the air blower is vorlie ^¬ quietly 26 is provided, which is arranged in a capacitor 11 connected with the Verdunster 12 Zulufttrakt 27th Via the line 17 and the supply air 27 so the used for receiving the water vapor in the evaporator 12 air in the separator is recycled.

The water introduced via the connecting line 21 to the condenser 11 for cooling the water vapor water leaves the Kon ^¬ capacitor 11 again via the supply line 10. In the condenser 11, however, the water used to condense the water vapor is previously pre-heated by the heat released during condensation heat. The preheated water then flows through the supply line 10 to the evaporator 12. An additional heat input into the water flowing through the supply line 10 is then effected via the heat exchanger 5 in the system according to FIG.

The originating from the separator 3 hot waste water is thus fed to the heat exchanger 5, in which a part of its heat is discharged to the circulating between the evaporator 12 and the condenser 11 water. This is followed by a relaxation at the pressure reducer 8 and then the introduction in the water cycle of the thermal separator comprising the evaporator 12 and the condenser 11.

The evaporation process in the evaporator 12 and also the condensation process in the condenser 11 are carried out in the present case preferably at temperatures below the boiling point. To sicherzu ^¬ that the contaminated water which is let through the input is introduced into the Verdunster 12 13, having a tempera ture ^¬ of less than 100 ° Celsius, the heat exchangers will be used shear. 5 In addition, the relaxation on the heat exchanger 5 and also on the pressure reducer 8 ensures a reduction in the pressure of the output side of the separator 3 at a high pressure contaminated water. The under high pressure and, for example, at temperatures of more than 125 ° C from the separator 3 effluent water is therefore initially ^¬ cooled by means of the heat exchanger 5 and then relaxed at the pressure reducer 8. Thus si ^¬ chergestellt that in temperatures of more than

100 ° Celsius abrupt boiling processes lead to pressure surges, which could cause damage to parts of Appendix 1.

The plant 1 shown in FIG. 2 corresponds in essential parts to that shown in FIG. However, here is the Einmün- point 9 of the pressure reducer 8 having line 7 downstream of the heat exchanger 5 in the supply line 10 is provided. Accordingly, the COM ^¬ Mende from the separator 3 contaminated water flows through the heat exchanger 5 only once and not as in the system 1 according to FIG 1 twice.

Then, the contaminated water is supplied via the valve 6 and the line 7 to the pressure reducer 8 and then di ^¬ rect, ie without renewed heating at the heat exchanger 5 via the inlet 13 to the water distributor 14 of the evaporator 12 supplied. Such a process scheme is favorable, for example, when the separator 3 leaving, contaminated water is relatively hot and therefore requires no further heating after relaxing the pressure reducer 8. In addition, in this litigation the entering at the mouth Steep 9 in the supply line 10 What ^¬ ser may very well be mixed with the coming from the condenser 11 water and this up heat coming from the condenser 11 water. Then there is another, direct heat transfer, without the need for another heat exchanger needs to be provided.

The plant 1 shown in FIG. 3 essentially corresponds to that shown in FIG. However, here a means for acquiring mechanical energy is provided instead of the pressure Minde ^¬ RERS 8, such as a turbine 30. The obtained when flowing through the turbine 30, mechanical energy 22 may be used for example, for operating the blower 26 and / or the pump. However, it is also possible to convert the mechanical energy by means of a generator 31 into electrical energy and to use this for driving pumps, fans or the like facilities of Appendix 1. Thus, in the system according to FIG. 3, the potential energy of the polluted water leaving the separator 3 under high pressure of, for example, 50 bar can be utilized well via the device embodied by way of example as the turbine 30.

The system 1 can also be designed in several stages. An example of such a system 1 is shown schematically in FIG. In this case, the contaminated water coming from the separator 3 via the line 4 is first fed to the heat exchanger 5 and gives off heat there. Subsequently, the contaminated wastewater in the present example three-stage system 1 flows through a second heat exchanger 32 and through a third heat exchanger 33, wherein each heat is emitted.

The contaminated water which is then already comparatively largely cooled then flows via the inlet 13 into the evaporator 12 and from there via the outlet 19 and the connecting line 21 into the condenser 11. The evaporator 12 and the condenser 11 belong to a stage 43 of the system - Ge 1, by which one of the present three thermal

Separating devices of Appendix 1 is provided. In the connecting line 21, the radiator 23 may be provided. The water heated by the condenser 11 flows - gegebe ^¬ appropriate, after intermediate cooling, to a further cooler 34 - into a condenser 35 which is associated with a further stage 36 or separating device Appendix 1. In this stage 36 and a evaporator 37 is provided.

From the condenser 35 of the second stage 36 of the system 1, the water flows to a condenser 38 of a first stage 39 or first thermal separator of the system 1. The guidance of the air flow in the individual stages 39, 36, 43 of the system 1 is shown in FIG simplicity ^¬ is not Darge. As shown herein by way of example, and Zvi ^¬ rule may be provided for intermediate cooling, a further cooler 40 to the capacitor 35 of the second stage 36 and the capacitor 38 of the first stage. 39

The water leaving the condenser 38 flows through the heat exchanger 5, that is to say through that heat exchanger which has the highest temperature of the three heat exchangers 5, 32, 33 shown in FIG. 4 for heating purposes. The water heated in this heat exchanger 5 is fed to a vaporizer 41 of the first stage 39 of the system 1.

The water leaving this evaporator 41 flows through the second heat exchanger 32 to the evaporator 37 of the second stage 36. The evaporator 37 of the second stage 36 leaving

Water flows via the third heat exchanger 33 to a valve 42, in which the water heated by the third heat exchanger 33 can be mixed with the water coming from the separator 3. From this valve 42, the water then flows into the evaporator 12, which in the present case is associated with the third stage 43 of the system 1. In this third stage 43, the lowest temperatures in the evaporator 12 are based on the temperatures of the evaporators 37, 41 of the other two stages 36, 39. Likewise, in this third stage 43, the lowest temperatures in the condenser 11 relative to the temperatures of the capacitors 35, 38 of the other two stages 36, 39 of the system 1 are present

By the successively flow-through capacitors 11, 35, 38 and evaporators 41, 37, 12 can be comparatively low temperature differences within the individual stages 39, set 36, 43. Thus, a great deal can be the input side of each evaporator 41, 37, 12 related to the Availability checked ^¬ supply heat for heating the air flow and thus used for providing steam.

In addition, with a small temperature difference between the evaporator 41, 37, 12 and the condenser 38, 35, 11 of the respective stage 39, 36, 43 altogether a particularly large heat difference, namely the heat difference between the hottest evaporator 41 of the first stage 39 and the coldest capacitor 11 of the third stage 43 are used. This brings a particularly high efficiency of the system 1 with it. There are then only comparatively low exergy losses.

The separation means in the form of stages 39, 36, 43 with the respective evaporators 41, 37, 12 and capacitors 38, 35, 11 thus serve to recover product water with a particularly high efficiency of the system 1.

By providing a thermal separation process, subsequent to the mechanical separation of the mixture in Sepa ^¬ rator 3 of the separation process in the separator 3 is not impaired. This is advantageous because so ensure can gen GETRA ^¬ that in the separator 3, a certain minimum temperature is present, which ensures the fluidity of the oil fraction in the mixture. The viscosity of the oil, which in Oil, water, gas and solids-containing mixture is contained in Sepa ^¬ generator 3, namely, depending on the temperature of the mixture.

In addition, the waste heat of the effluent from the separator 3 water or mixture is used as a heat source for the convectionally driven evaporation ^¬ ge process. Furthermore, the plant 1 allows the use of the heat of the separated water and also an internal heat recovery via the at least one capacitor 11, 35, 38. Thus, virtually all of the separator 3 - or from two sequentially connected separators - originating wastewater at least one Be subjected to Verduns- tion and Rekondensationszyklus. This he ^¬ laubt a recovering almost 100% of present in the mixture in the separator 3 the water as clean product water or process water.

Claims

claims

1. Plant for the treatment of water produced by the extraction of a fossil fuel containing contaminated and geothermal energy, comprising at least one separating device (39, 36, 43) for separating contaminants from product water to be extracted from the water,

characterized in that

the at least one separating device (39, 36, 43) comprises at least one evaporator (41, 37, 12) and at least one condenser (38, 35, 11), via which the water containing the impurities can be guided in a circuit, wherein the at least a separating device (39, 36, 43) is assigned at least one heat exchanger (5, 32, 33), in which the water containing the geothermal energy can be introduced as a heating medium, wherein by means of at least one Wärmetau ^¬ shear (5, 32, 33) at least part of the geothermal energy can be transmitted to the water which can be supplied to the at least one evaporator (41, 37, 12) and contains the impurities.

An installation according to claim 1, characterized in that the at least one evaporator (41, 37, 12) has a first inlet (13) for the contaminated water and a second inlet (16) over which one for receiving from the contaminated one water-derived water vapor formed gaseous medium in the Verdunster (41, 37, 12) can be introduced, wherein the at least one Verdunster (41, 37, 12) Wenig ^¬ least an outlet (44) through which the with the water vapor-laden gaseous medium from the at least ei ^¬ nen evaporator (41, 37, 12) can be discharged, and wherein by means of the at least one capacitor (38, 35, 11) of the contained in the gas ^¬ shaped medium water vapor can be converted into the product water.

3. Plant according to claim 2, characterized in that the gaseous medium, which in the at least one evaporator (41, 37, 12) receives water vapor, to the at least one Condenser (38, 35, 11) transported and releases there by Konden ^¬ sation, ambient air includes or is.

4. Plant according to claim 2 or 3, characterized in that the gaseous medium, which in the at least one evaporator (41, 37, 12) absorbs water vapor, transported to the at least one capacitor (38, 35, 11) and there by condensation an inert gas comprises or is, where ^¬ in devices for gas-tight sealing of the system and / or for evacuating the system and / or for storing or generating the inert gas and / or for filling the inert gas in the at least one separating device (39, 36, 43) are provided.

5. Installation according to one of claims 2 to 4, characterized in that the at least one evaporator (41, 37, 12) ei ^¬ nen further outlet (19), which via a connecting line (21) with the at least one capacitor (38 , 35, 11) is coupled, via which water cooled by the gaseous medium from the at least one evaporator (41, 37, 12) can be fed to the at least one condenser (38, 35, 11) for liquefying the water vapor.

6. Plant according to claim 5, characterized in that in the connecting line (21) at least one cooling device

(23) is arranged.

7. Plant according to claim 5 or 6, characterized in that the plant has a feed line (10) via which the liquefying the water vapor in the at least one condenser (38, 35, 11) used water in the at least one evaporator (41 , 37, 12) is traceable.

8. Plant according to claim 7, characterized in that the supply line (10) has a confluence parts (9), via which the impurities having and the at least one evaporator (41, 37, 12) to be supplied water in the of the at least one condenser (38, 35, 11) coming water can be introduced.

9. Installation according to one of claims 1 to 8, characterized in that by means of at least one heat exchanger (5, 32, 33) a temperature of the contaminants and the at least one evaporator (41, 37, 12) to be supplied water reducible is.

10. Installation according to one of claims 1 to 9, characterized marked ^¬ characterized in that the plant (1) at least two Trenneinrich ^¬ lines (39, 36, 43) with a respective evaporator (41, 37, 12) and a respective capacitor ( 38, 35, 11), wherein the evaporators (41, 37, 12) and the capacitors (38, 35, 11) are each successively flowed through in the system (1) are arranged.

11. Plant according to claim 10, characterized in that upstream of the respective evaporator (41, 37, 12) of the at least two separating devices (39, 36, 43) of the at least one heat exchanger (5, 32, 33) and / or upstream the respective capacitors (38, 35, 11) of the at least two

Separating devices (39, 36, 43) each have a cooling device (23, 34, 40) is arranged.

12. Plant according to one of claims 1 to 11, characterized in that an inlet (13) of the impurities having water in the at least one evaporator (41, 37, 12) at least one pressure reducer (8) is connected upstream, by means of which a pressure is reducible the introduced into the at least one Verdun ^¬ ter (41, 37, 12) water.

13. Plant according to claim 12, characterized in that the at least one pressure reducer (8) is designed as a device (30) for obtaining mechanical and / or electrical energy.

14. Plant according to one of claims 1 to 13, characterized in that in the at least one evaporator (41, 37, 12) and / or in the at least one condenser (38, 35, 11) there is a pressure which a pressure in the environment of the system is the same.

15. Installation according to one of claims 1 to 14, characterized in that the system comprises at least one upstream of the at least one evaporator (41, 37, 12) arranged filter device (3) for pre-cleaning of the impurities having water.

16. A method of processing accumulating, contaminated in the promotion of a fossil fuel and geothermal mix energy-containing water, wherein means we ^¬ nigstens a separating device (39, 36, 43) are separated contaminants from the water and so product water is obtained, characterized in that the Impurities ^¬ gen containing water in the processing at least one Trenneinrich- (39, 36, 43) in a circuit via at least one

Evaporator (41, 37, 12) and at least one capacitor (38, 35, 11) is guided, wherein the at least one Trennein ^¬ direction (39, 36, 43) at least one heat exchanger (5, 32, 33) is assigned, in which the water geothermal energy containing is introduced as a heating medium, at which ^¬ least supplied by the at least one heat exchanger (5, 32, 33) a portion of the geothermal energy to the at ^¬ least a Verdunster (41, 37, 12) and the polluting water is transferred.

17. The method according to claim 16, characterized in that the at least one evaporator and / or the at least one condenser are operated at a temperature which is lower than the boiling point of water in the at least one evaporator and / or in the at least one condenser prevailing pressure.

18. The method according to claim 16 or 17, characterized in that the potential energy of the high pressure on ^¬ falling water in the plant for the operation of gaseous or liquid media promoting auxiliary equipment is used.