Method and device for the treatment of liquids

Abstract

A process for the treatment of liquids, in which the liquid to be treated consists of a base liquid with essentially liquid and / or gaseous and / or salt-like impurities contained and / or dissolved therein, and in which a hot carrier gas stream laden with water vapor is present as the hot water vapor carrier gas stream, wherein the separation of the impurities from the base liquid is carried out in such a way that the liquid to be treated is fed as treatment liquid for preheating and pre-cleaning to at least one preheating / separation device (7, 14), in which the treatment liquid is preheated to a temperature below the boiling point of the base liquid, so that the liquid impurities which boil low relative to the base liquid evaporate and / or the gaseous impurities are thermally expelled and subsequently the thus evaporated and / or expelled impurities are separated, that the thus preheated and pre-cleaned treatment liquid is fed to a carrier gas in a closed circuit and this mixture is evaporated by heat supply to a wet carrier gas-vapor mixture in such a way that the base liquid is evaporated and the liquid impurities with boiling temperatures above the boiling temperature of the base liquid remain as residual liquid and / or the salts contained in the base liquid remain as brine, that this wet carrier gas-vapour mixture is fed to a concentrate separator (30) in which the residual liquid portion and / or the brine is separated as a concentrate, that the carrier gas-vapor mixture, freed from the residual liquid portion and / or the brine and thus purified, is compressed as a carrier gas-dry vapor mixture and then cooled, so that the base liquid condenses and is separated as condensate in a downstream condensate separator (43) and, in addition, after the condensate separator (43) there is a hot carrier gas loaded with uncondensed water vapor, which forms the hot water vapor carrier gas stream, characterized by that at least a partial stream of the hot steam carrier gas stream is subjected to steam electrolysis in which at least a portion of the hydrogen and / or oxygen is split off from the hot steam carrier gas stream and a dried carrier gas stream is produced, wherein at least a portion of the dried carrier gas stream is fed to the liquid to be treated.

Description

The invention relates to a method for processing liquids according to the preamble of claim 1 and to a device for processing liquids according to the preamble of claim 16.In the treatment of liquids, such as, for example, sea, brackish or waste water and other waste liquids, in particular to drinking and service water, by means of evaporation in a hot gas stream with subsequent condensation, as is described, for example, in the generic EP 1 363 855 B1, water vapor amounts which may not be negligible may be present in a hot carrier gas stream which is freed from a base liquid condensate by means of a condensate separator and which preferably uses air or inert gas as carrier gas, depending on the respectively predetermined process pressure and the respectively predetermined process temperature. These amounts of water vapor present in the hot carrier gas stream may significantly reduce the possible amount of re-loading of the carrier gas, which may adversely affect the overall efficiency of the processing process. From EP 1 363 855 B1, it is only known to transfer the condensate removed from the condensate separator into a condensate collecting container and to supply the top product of this condensate collecting container, which still has remaining carrier gas constituents, to a heat exchanger as a gas dryer, which is in turn followed by a further condensate separator in order to introduce the remaining carrier gas from the first condensate back into the carrier gas circuit. This is intended to avoid carrier gas losses in the closed carrier gas circuit.DE 31 05 550 A1 relates to a process for multistage treatment of fresh water, brackish water, seawater and wastewater, in which two membrane separation stages are combined and the final concentrate is thermally treated further. Waste heat from solar heat, cooling media or exhaust gases is used to save energy. In addition, an integrated recovery of sodium hydroxide solution and hydrochloric acid by electrolysis and downstream synthesis is described in order to regenerate ion exchangers efficiently. The aim is an increased product yield, a reduced energy and operating medium consumption and economic disposal of the concentrates.DE 199 31 866 A1 describes a method and an apparatus for processing waste liquids, in particular with liquid impurities. A waste liquid / carrier gas mixture is evaporated, the moist carrier gas-vapor mixture formed is treated in a concentrate separator and the resulting dry carrier gas-vapor mixture is compressed and cooled. The carrier gas is circulated, thereby minimizing carrier gas losses. Recovering heat from the condensate and the concentrate enables an energy-efficient mode of operation with simultaneous reduction of the carrier gas requirement.Furthermore, U.S. Pat. No. 6,796,250 B1 relates to a system for recovering and utilizing waste water, in particular grey water and solid waste water residues. Vapor and electricity are generated by evaporation. Electrolytic decomposition of the condensate provides hydrogen and oxygen as other energy sources. The system can use different fuels and helps operate with alternative energy such as solar or wind power. It aims at energy-efficient conversion of waste water into usable energy for heating purposes and power generation.In contrast, it is an object of the present invention to provide a method and an apparatus for processing liquids, in particular sea and / or brackish water and / or a waste liquid and / or waste water, by means of which a purification of the liquids is achieved in a simple and effective manner and a carrier gas stream which is as pure as possible is obtained.This object is achieved with the features of the independent claims. Advantageous further embodiments are the subject matter of the dependent claims which refer back thereto.According to the invention, for gas drying or gas post-drying, at least a partial stream of a hot carrier gas laden with water vapor is subjected to a water vapor electrolysis as a hot water vapor carrier gas stream, in which at least some of the hydrogen and / or oxygen gas is split off from the hot water vapor carrier gas stream and a dried carrier gas stream is generated.In conjunction with such a method procedure and configuration, it is particularly advantageous that, owing to the water already present in vapor form, a considerable reduction in the electrical energy consumption required for electrolysis can be achieved. This reduction in energy is made possible by the fact that heat of vaporization has already been supplied as energy to the water vapor for the vaporization of the water in preceding method steps, so that the expenditure of electrical energy for the electrolysis is reduced. The water vapor carrier gas stream preferably has a temperature between 70° and 300° C., preferably between 90° and 250° C., specifically at operating pressures or pressures between 1 bar and 11 bar absolute, depending on the operating conditions currently prevailing for a water treatment or wastewater purification apparatus, for example, which also corresponds to the operating conditions for the water vapor electrolysis, so that the hot water vapor carrier gas stream-in particular from a device for treating liquids, in particular sea and / or brackish water and / or a waste liquid and / or wastewater, as will be explained in more detail below-can be used immediately and directly to the water vapor electrolysis according to the invention for drying the water vapor carrier gas stream and thus for generating a dried carrier gas stream. Such a dried carrier gas stream can then be recycled into the process, wherein this dried carrier gas stream can be recharged with a substantially larger amount of liquid, for example, to be treated than would be the case without drying with the original hot water vapor carrier gas stream.In addition to these advantages just mentioned, the invention has the advantage that it can be used to obtain, for example, very pure hydrogen from waste liquids as treatment liquids, which can in turn be supplied to another use, for example as fuel for engines or internal combustion engines or as coolant in power plants or other industrial plants, in order to show only a few possible uses.Suitable electrolysis processes are, in particular, alkaline electrolysis, such as, for example, alkaline pressure electrolysis, proton exchange membrane electrolysis and high temperature electrolysis, and specifically both autothermal and allothermal electrolysis processes. As experiments by the inventors have shown, the energy requirement for the gas drying according to the invention of a hot steam carrier gas stream is only about 2.7 kWh / m 3 of hydrogen, whereas the energy requirement for a conventional electrolysis for generating hydrogen is substantially higher and, depending on the electrolysis method, is between about 9-18 kWh / m 3 of hydrogen.According to a particularly preferred method procedure and embodiment, the hot water vapor carrier gas stream for water vapor electrolysis is conducted into a reaction space of a water vapor electrolyser in which at least one anode and at least one cathode are arranged as electrodes, to which preferably the still required electrical energy for splitting off the hydrogen and / or the oxygen is supplied by a rectifier as energy supply device.In principle, the entire hot water vapor carrier gas stream can be fed to the water vapor electrolysis. However, it is preferred that a quantity of the hot water vapor carrier gas stream which is predetermined as a function of predetermined parameters, in particular of the gas drying degree and / or of the hydrogen demand and / or of the oxygen demand, is supplied to the water vapor electrolysis. Thus, gas drying optimized with regard to the energy consumption can take place by means of the water vapor electrolyser. Thus, for example, depending on the processing process and the required degree of gas drying, for example, it can be specified that, in order to fulfil all specifications, only a specific partial stream of the steam carrier gas stream is subjected to gas drying in order to provide a carrier gas stream with the desired degree of gas drying. Specifically, for this purpose, the quantity of hot water vapor carrier gas supplied to the water vapor electrolysis is predefined by means of a regulating device, by means of which an adjusting and / or measuring device, which is arranged in the feed line to a water vapor electrolyser and is coupled to the regulating device and is formed in particular by a flow rate adjusting and measuring device, is actuated. Furthermore, it is further preferred here that the dried carrier gas stream coming from the steam electrolysis is passed via at least one measuring device, by means of which the content of hydrogen and / or oxygen in the dried carrier gas stream can be determined. This information is then made available to the control device as a parameter, for example as an actual value parameter, so that the quantity of the hot water vapor carrier gas stream to be supplied to the water vapor electrolysis can be determined in a simple and reliable manner.According to a further particularly preferred embodiment and method procedure, it is provided that at least a portion of the hydrogen and / or oxygen obtained in the water vapor electrolysis is drawn off from the water vapor electrolyser and stored or temporarily stored in a gas store, in particular in a compressed gas store. In order to be able to draw off the hydrogen and / or oxygen obtained in the context of the steam electrolysis, a suction and / or pump device is preferably provided between the steam electrolyser and the respective compressed gas store, which suction and / or pump device is preferably formed by a vacuum pump. In order to prevent an undesired return flow in the direction of the suction and / or pumping device, a shut-off valve as a shut-off device and / or a nonreturn valve as a nonreturn device is preferably arranged for this purpose in the region of the respective compressed gas store.Likewise, according to a particularly preferred embodiment, in order to avoid an undesired reverse flow in the direction of the water vapor electrolyser, a shut-off valve as shut-off device and / or a nonreturn valve as nonreturn device is arranged between the water vapor electrolyser and the respective suction and / or pump device. The respective pipelines between water vapor electrolyser and, for example.Vacuum pump or compressed gas storage devices are respectively assigned to those electrodes in which the gas to be sucked off is formed. For the formation of gas, membrane arrangements are provided in the reaction space of the electrolyser, which bring about that only the respectively desired gas, i.e. hydrogen and / or oxygen, can diffuse to the respectively assigned electrodes, while the residual gas is retained in the reaction space as pure, dried carrier gas and can be drawn off via a separate pipeline as carrier gas line. At least a portion of this dried carrier gas can then be supplied to a liquid to be treated, in particular to a sea and / or brackish water and / or wastewater or to a waste liquid to be treated, as is explained in more detail below.According to a preferred embodiment, the gas accumulator designed as a compressed gas accumulator is assigned a pressure regulating and / or alarm device which actuates an exhaust device as a function of a predetermined overpressure via a blow-off line, which preferably has a shut-off device and / or a non-return device. This blow-off device, which is formed in particular by a blow-off valve, can be bypassed by means of a bypass line in which a mechanical safety valve is arranged. Such a bypass line ensures that, for example, in the event of a failure of the pressure regulating and / or alarm device, the gas can be blown off because of overpressure in any case. The mechanical safety valve can be designed, for example, preferably with regard to an overpressure threshold value such that it only responds later than the electronic blowing device assigned to the pressure regulating and / or alarm device. In particular a safety torch is also assigned to a hydrogen storage as a gas storage device in order to ensure that the hydrogen gas escaping in the event of overpressure can be safely filtered off.A further important advantage of the water vapor electrolysis of the water present in vapor form in the carrier gas is that it is thus possible in principle to suck off and store only the hydrogen gas while leaving the oxygen produced in the carrier gas. As a result, the oxygen content in the carrier gas can be increased and, in the case of desired wet combustion, can be used as oxidizing agent, so that no external oxygen supply is required. Alternatively, however, the oxygen produced can also be extracted and stored in addition to the hydrogen in order to supply it to the circuit in predefined amounts, for example at predefined times, for example in the case of desired wet combustion. Specifically, for this purpose, an oxygen pipe can be assigned, for example, to an oxygen storage as gas storage, preferably together with a shut-off device, preferably a shut-off valve, and / or a non-return device, for example a non-return valve, via which a predefined amount of oxygen can be fed into the dried carrier gas stream at predefined times by means of a control and / or regulating device. Particularly preferably, the oxygen pipeline is branched off from the gas storage pipeline and opens into a carrier gas line which conducts the dried carrier gas stream. However, it is likewise possible to supply the oxygen to other uses as well. Thus, the oxygen can be used, for example, for the additional oxygen supply of biological wastewater purification plants.Furthermore, it is provided according to the invention that the treatment liquid is fed to at least one preheating separating device for preheating and prepurification before the mixing of the dried carrier gas, which device has in each case at least one preheating heat exchanger and a separating device connected downstream of the preheating heat exchanger. In this, the treatment liquid is preheated by the preheating heat exchanger to a temperature below the boiling temperature of the base liquid, so that the impurities having a low boiling point with respect to the base liquid evaporate and / or the gaseous impurities are thermally driven out, wherein the evaporated and / or driven-out impurities are separated out in the separating device of the at least one preheating separating device. Thus, before the supply of the treatment liquid to a carrier gas mixing device, those low-boiling liquid impurities and / or gaseous impurities which can no longer be separated from the treatment liquid after the supply of the carrier gas are advantageously separated from the treatment liquid. With such a measure, therefore, a complete separation of almost all liquid and gaseous impurities in the treatment liquid can be achieved, so that the efficiency of the entire plant and of the entire process is thereby very high and an overall extremely economical operation of the plant is possible.In particular, with such a method and such an apparatus, a very ready spectrum of a wide variety of treatment liquids with a large number of a wide variety of liquid and / or gaseous contaminants can be treated in an effective and economic manner. Thus, such a process procedure and apparatus is particularly well suited and advantageous in particular also for water recovery, e.g. in the form of drinking water or service water from sea and / or brackish water, since, in the context of preheating and prepurification, the carbon dioxide dissolved therein in large quantities and the carbon dioxide formed during the thermal decay of H 2 CO 3 can be separated and removed. The salts present in the base liquid can then be separated out as salt sols in the concentrate separator as part of the evaporation of the base liquid.Advantageously, the expulsion of gaseous contaminants from the treatment liquid prior to the supply of the carrier gas also ensures that these gaseous contaminants cannot accumulate in the closed carrier gas circuit. Advantageously, down times of the plant are thereby avoided in order to separate the gaseous impurities from the carrier gas, so that overall an economical operation of such a plant with long run times is very well possible. In addition, in contrast to conventional installations, the pipelines and apparatuses can therefore also be dimensioned and designed to be correspondingly smaller and less expensive overall. This is not least because by withdrawing the low boiling liquid impurities before supplying carrier gas, a part of the treatment liquid has already been withdrawn as an impurity.Advantageously, in such a method procedure and device, in which a carrier gas is supplied as entraining gas to a processing liquid to be processed, a separation of the liquid impurities, fractionated according to the boiling point temperature of the liquid impurities, and / or a expulsion of the gaseous impurities from the base liquid thus processed for environmentally friendly disposal and recycling takes place. The impurities can also be valuable materials which can be recycled and do not have to be disposed of.A particularly advantageous efficiency of the plant and of the process is achieved if the treatment liquid to be treated is fed successively to at least two preheating separation devices connected in series. With such a multistage preheating and prepurification, a particularly good and efficient separation effect with regard to the separation of the low-boiling impurities and / or the expulsion of the gaseous impurities is achieved. For such an increased separating effect, a particularly high efficiency of the plant as a whole and in particular with regard to preheating and prepurification can be achieved. This can also be achieved in particular if the treatment liquid is preheated in the preheating heat exchanger to as close as possible to the evaporation temperature of the base liquid, since this promotes a subsequent very fine distribution of the preheated and prepurified treatment liquid in the carrier gas.According to a further preferred embodiment and method procedure, it is provided that the treatment liquid to be treated preheated in the at least one preheating heat exchanger of each preheating separating device is fed to a pressure-relieving device as a component of the separating device, with which effective separation of the low-boiling vaporous impurities and / or gaseous impurities takes place. Particularly advantageously, the low-boiling vaporous impurities and / or the gaseous impurities can be fed from the expansion device via a line to a cooling device with a heat exchanger as a further constituent of the separation device and stored in a collecting container, so that during the cooling process a reduced pressure is generated in the line, through which the separated impurities are sucked out of the expansion device. Advantageously, this achieves the separation and separation of the impurities in a simple manner without great outlay on components and apparatus. The expansion device can be formed by an expansion container with a pump connected upstream or else by a pervaporation membrane plant.A particularly advantageous method is achieved with an arrangement in which each preheating heat exchanger is formed by a condensate-treatment liquid heat exchanger, with which preheating takes place by the hot condensate coming from the condensate container. In addition, a further heat supply for preheating the treatment liquid can take place in a concentrate-treatment liquid heat exchanger through the hot concentrate coming from the concentrate collecting container, wherein the concentrate-waste liquid heat exchanger is connected upstream of the at least one preheating separating device. With such a process procedure, the energy consumption can be substantially reduced overall, since almost all hot streams are used to heat colder streams. This also applies in particular when at least a portion of the heat supply for the evaporation to the wet carrier gas-vapor mixture takes place in at least one evaporator-condensation heat exchanger through the outflowing, compressed and purified carrier gas-dry vapor mixture.According to the invention, it is provided that the carrier gas is guided in a separate carrier gas circuit in order to minimize the carrier gas losses. In such a closed carrier gas circuit, because of the low carrier gas losses, relatively expensive and valuable inert gases can also be used as carrier gases, which are regularly preferred in their function as a carrier gas for the waste liquids compared to air, for example, since these, unlike air, for example, cannot react with certain other components, in particular gaseous components of the waste liquids. Furthermore, for obtaining residual carrier gas present in the separated condensate, additional gas drying can be provided behind a condensate collecting container in order to dry wet residual carrier gas from the condensate collecting container and feed it to the carrier gas circuit in the desired dry state. In a specific method procedure and embodiment for this purpose, the condensate obtained in the condensate separator is discharged via a condensate discharge line with a shut-off valve into a condensate collecting container, wherein a discharge which is as free from carrier gas loss as possible is achieved via a fill level measurement in conjunction with a regulating valve. The top product of the condensate collecting container, which likewise has carrier gas constituents, is fed to an exhaust line connected at the top to the condensate collecting container and is then fed via a heat exchanger as a gas dryer with downstream condensate separator for carrier gas drying and likewise via the gas line in a further carrier gas circuit likewise in turn to the carrier gas feed line.In the event that, for example, losses of carrier gas still occur in the system after a longer operating time, carrier gas can furthermore be easily replenished via a carrier gas reservoir coupled to the carrier gas circuit. The supply is effected by a simple coupling into the carrier gas circuit present, so that the plant does not need to be stopped for this purpose, which is uneconomical but can be continued to operate continuously.In the case where air is provided as carrier gas, it can preferably be sucked in from the environment, for example via a compressor which is provided with a suction filter.The invention is explained in more detail with reference to drawings.The following are shown: FIG. 1 shows a schematic flow diagram of an apparatus for processing a liquid according to a first method procedure, in which only hydrogen is split off in the context of steam electrolysis, FIG. 2 shows a schematic flow diagram of an apparatus for processing a liquid with an alternative method procedure, in which both hydrogen and oxygen are split off in the context of steam electrolysis, and FIG. 3 is a schematic flow diagram of a device for processing a liquid with an alternative method procedure, in which a regulating device is provided, with which a steam electrolyser is charged with a predetermined quantity of a hot steam carrier gas mixture.Processing liquids, such as waste liquids obtained in production, for example solvents in different dilutions, or sea and / or brackish water, which are to be processed to drinking and service water, are, in a process procedure according to FIG. 1, optionally prepurified, fed via an inlet 1 and by means of a pump 2 for preheating and prepurification to a preheating separating device which has a preheating heat exchanger 7 and a separating device 14 connected downstream of the preheating heat exchanger 7. The preheating heat exchanger 7 is here simultaneously designed as a condensate treatment liquid heat exchanger, which is explained in more detail below, wherein the temperature of the treatment liquid to be purified is heated as close as possible to a desired evaporation temperature in the preheating heat exchanger 7 depending on the pressure present.In the separation device 14, the vapor produced according to its boiling point temperature and / or the inert gases present, for example, in the sea and / or brackish water or the gaseous CO 2 present and produced are separated from the preheated liquid. The separated vapor and / or gas is supplied via a line 16 to a cooling device with heat exchanger 17 and stored in liquefied form in a collecting container 18. During the cooling process, a reduced pressure arises in the line 16, by means of which the removal of the gas and / or vapor produced from the separation device 14 is effected. In the event that no separation by means of the separation device 14 should be necessary, this can also be bridged by means of a bypass line 11 with corresponding shut-off devices 12 and 13. The feed line from the preheating heat exchanger 7 to the separating device 14 is denoted here by the reference numeral 9. In this supply line 9 a shut-off device 10 is also provided.The separating device 14, which is designed, for example, as a pressure release vessel, is also assigned a pump 21, which together form a pressure release device.The treatment liquid preheated and prepurified in this way is then guided via a pipe line 22 to a mixing device 8, which is further connected to a carrier gas line 63 and in which the preheated and prepurified treatment liquid is very finely distributed in the dried carrier gas stream supplied by the carrier gas line 63. Via a mixture line 25, this resulting wet carrier gas-vapor mixture is conducted into an evaporator / condensation heat exchanger 27 in which a further heating with the aim of superheating the carrier gas-vapor mixture takes place. The required temperatures and operating pressures of the carrier gas-vapor mixture are dependent on the constituents to be separated and the thermal variables of the waste liquid to be purified. Therefore, temperatures between 50 and 250° C. and operating pressures between 0.5 bar and 20 bar may be required.The wet carrier gas-vapor mixture with the liquid residue that has a higher boiling point with respect to the base liquid and the salts of the treatment liquid to be purified contained in the base liquid is then introduced by means of a pipeline 28 into a concentrate separator 30, in which this liquid residue and / or a salt brine is separated as a concentrate. This concentrate separator 30 can be designed, for example, as a cyclone or baffle plate separator. In the case of the baffle plate separator, both single-plate and multi-plate separators can be used.The carrier gas-dry vapor mixture now no longer containing residual liquid leaves the concentrate separator 30 via a line 31 and is fed to a droplet separator 32, in which concentrate still contained in the carrier gas-dry vapor mixture can be separated and fed to a concentrate collecting container 97 via a line 98. The concentrate collected in the concentrate collecting container 97 is discharged via a pipe line 99, wherein the hot concentrate can optionally serve for preheating the waste liquid 1 fed to the preheating heat exchanger 7, which is not shown here, however.The carrier gas-dry vapor mixture leaving the droplet separator 32 is fed via a pipeline 33 to a compressor 36, as a result of which the carrier gas-dry vapor mixture is brought to the desired operating pressure with a simultaneous temperature increase. This compressed carrier gas-dry vapor mixture reaches the evaporator / condensation heat exchanger 27 via a pressure line 37 and is cooled there, with condensation of the dry vapor of the carrier gas-dry vapor mixture, namely the base liquid of the treatment liquid, wherein at the same time heating of the wet carrier gas-vapor mixture, which comes from the mixing in of the dried carrier gas stream, takes place.The condensate is then passed via a pipe 41 to a condensate separator 43 in which the condensate is separated. A cyclone separator or a baffle plate separator, such as a single plate separator or multiplate separator, is used here as the condensate separator 43.The condensate obtained in the condensate separator 43 is collected in a condensate collecting container 44 and reaches a separator 48 via a pipe line 45 where any medium boilers still present, such as H 4 N 2, Cl 3 N, H 2 O 2, CCl 3 NO 2, are separated out in conjunction with a cooling device 50 and a collecting container 51, so that the condensate now formed by a high-purity base liquid is guided via a pipe line 52 to the preheating heat exchanger 7, from which it leaves via a pipe line 54 as service water, for example, after the heat exchange with the treatment liquid.The hot carrier gas laden with uncondensed steam reaches the condensate separator 43 as a hot carrier gas stream of steam via a shut-off device 57 into a reaction space of a hydrogen electrolyser 58, in which at least one anode 60 and at least one cathode 59 are arranged. These electrodes 59, 60 are supplied with electrical energy by means of a rectifier 62. The cathode 59 is separated from the reaction space by means of an ion-specific membrane through which the hydrogen gas produced can diffuse, but the residual gas is not. The extraction takes place via a pipe 69 in which a shut-off device 70 and a non-return device 71 are arranged, namely by means of a vacuum pump 72; via a pressure line 73 in which a non-return device 75 and a shut-off device 76 are arranged, the hydrogen gas is conveyed into a compressed gas reservoir 77. A pressure regulating and alarm device 78 for monitoring and securing is mounted on the compressed gas reservoir 77, by means of which a possible overpressure is discharged in a controlled manner via a line 79 with a shut-off valve 80 and a non-return securing means 81 by means of an automatic blow-off valve 82. For additional safety, a bypass line 84 with a mechanical safety valve 85 is provided. The outflowing hydrogen gas is harmlessly burnt by means of the safety torch 83. The afterdried carrier gas, on the other hand, returns from the electrolyser 58 via the line 63 with a flow rate measuring device 65 and a pressure and temperature measuring device 64 back into the carrier gas circuit.As can be further seen from the flow chart of FIG. 1, an emergency relief is provided via the lines 105, 106 with safety valves 107, 108 arranged therein in connection with the pressure line 37, which, however, will not be discussed in more detail at this point.Furthermore, between the pressure line 37 and the discharge line 99 from the concentrate collection container 97, a pressure line 102 is provided, which can be connected by means of shut-off devices 103 and 104, and by means of which flushing for the pressure line 37 via the line 99 is possible.As can be further seen from FIG. 1, in the case of air as carrier gas, air can be sucked in from the environment via a compressor 86 with suction filter and fed via an air line 88 into the carrier gas circuit, e.g. for starting up the device or for replenishing carrier gas.FIG. 2 shows a schematic flow diagram of an alternative apparatus which differs from the apparatus according to FIG. 1 only in the separation of both hydrogen gas and oxygen gas, so that reference is made below only to this and reference is made to the explanations relating to FIG. 1 made above with regard to the remaining process procedure and the structure.The hot carrier gas laden with uncondensed water vapor thus reaches, after the condensate separator 43, via a shut-off device 57, a reaction space of the hydrogen electrolyser 58, in which in turn an anode 60 and cathode 59 are arranged as electrodes, which are supplied with the necessary electrical energy by means of a rectifier 163. Both the cathode 59 and the anode 60 are separated from the reaction space by means of ion-specific membranes through which the hydrogen gas obtained in each case or the oxygen gas obtained in each case can diffuse, but the residual gas, i.e. the pure carrier gas, cannot. The hydrogen gas is sucked off via a pipe 164, in which a shut-off device 165 and a non-return device 166 are arranged, specifically by means of a vacuum pump 167. Via a pressure line 168 in which a non-return device 169 and a shut-off device 170 are arranged, the hydrogen gas is conveyed into a compressed gas reservoir 171. On the compressed gas reservoir 171 there is again a pressure regulating and alarm device 172 for monitoring and securing, through which a possible overpressure can be discharged, via a line 173 with a shut-off valve 174 and a non-return safety 175, namely by means of an automatic blow-off valve 176. For additional safety, a bypass line 178 with a mechanical safety valve 179 is provided, analogous to the embodiment according to FIG. 1, Here too, outgoing hydrogen gas is harmlessly burnt by means of a safety torch 177.The oxygen gas produced is conveyed by means of a vacuum pump 183 via a suction line 180 with a non-return device 182 and a shut-off device 181, as well as a pressure line 184 and 185 with a non-return device 186 and a shut-off device 187 into a compressed gas accumulator 188 with a pressure regulating device 189. A pressure relief device, consisting of a blow-off line 190 with a non-return device 192 and a shut-off device 191 and an actuatable blow-off valve 193, is arranged on the compressed gas reservoir 188. The blow-off line 190 has a bypass 194 with a mechanical safety valve 195. The oxygen pressure line 184 is connected to a carrier gas line 199 by means of a pressure line 196 in which a non-return device 197 and a shut-off device 198 are arranged, so that partial recirculation of oxygen into the carrier circuit can take place according to the respective requirements if this should be required according to the respective task. The postdried carrier gas returns from the electrolyser 58 via the carrier gas line 199 with a flow rate measuring device 100 and a pressure and temperature measuring device 101 into the carrier gas circuit again.Finally, FIG. 3 shows a schematic flow diagram of a further variant of the invention, in which essential plant constituents are likewise in turn identical to those of the embodiments of FIGS. 1 and 2, and therefore reference is made to the relevant embodiments of FIG. 1. In contrast to the embodiments of FIGS. 1 and 2, according to the embodiment of FIG. 3, according to the requirements for the degree of drying of the dry carrier gas stream or also depending on the need for hydrogen, only a portion of the hot carrier gas laden with water vapor can be fed to a water vapor electrolyser. The selected portion of hot, wet water vapor-carrier gas mixture is conducted by means of a quantity measuring device 263 in a feed line 262 to the electrolysis cell or to the electrolyser 265, the preselected quantity being adjusted by means of the flow quantity measuring device 263 via a regulating valve 264. At least one anode 267 and one cathode 266 are arranged in the electrolyser 265. These electrodes 266, 267 are supplied with electrical energy by means of a rectifier 269. The cathode 266 is separated from the reaction space by means of an ion-specific membrane, through which the hydrogen gas produced can diffuse, but the residual gas is not. The extraction is effected here via a pipe 272, in which a shut-off device 273 and a non-return device 274 are arranged, namely by means of a vacuum pump 275. Via a pressure line 276, in which a non-return device 278 and a shut-off device 279 are arranged, the hydrogen gas is conveyed into a compressed gas reservoir 280. A pressure regulating and alarm device 281 for monitoring and securing is mounted on the compressed gas reservoir 280, by means of which device, via a line 282 with a shut-off valve 283 and a non-return securing means 284, a possible overpressure can be discharged by means of an automatic blow-off valve 285. For additional safety, a bypass line 286 with a mechanical safety valve 287 is also provided here in the manner already described above in connection with FIG. 1. The outflowing hydrogen gas can again be flamed off harmlessly by means of a safety torch 283. The postdried carrier gas passes from the electrolyser 265 via a line 270 with a flow rate measuring device 250 and a pressure and temperature measuring device 249 back into the carrier gas circuit via a line 248. Via this line 248, the partial flow of the hot water vapor carrier gas flow, which may not be introduced into the electrolyser 265, is also fed back into the carrier gas circuit in the manner described above. The content of hydrogen in the dried carrier gas stream can be measured by means of a measuring device 271, which contains feedback to the regulating valve 264 together with flow rate measurement via the quantity measuring device 263.The process procedure and apparatus according to FIG. 3 were described here analogously to FIG. 1 with only the elimination of hydrogen. Of course, this variant can also be used in conjunction with a configuration according to FIG. 2, according to which both hydrogen gas and oxygen gas are split off during the electrolysis.List of reference characters1 Feed 2 Pump 7 Preheating heat exchanger 8 Mixing device 9 Feed line 10 Shut-off device 11 Bypass line 12 Shut-off device 13 Shut-off device 14 Separation device 16 Suction line 17 Cooling device 18 Collecting container 21 Pump 22 Pipe line 25 Mixture line 27 Evaporator / condensation heat exchanger 28 Pipe line 30 Concentrate separator 31 Pipe line 32 Droplet separator 33 Pipe line 36 Compressor 37 Pressure line 41 Pipe line 43 Condensate separator 44 Condensate collecting container 45 Pipe line 48 Separator 50 Cooling device 51 Collecting container 52 Pipe line 54 Pipe line 57 Shut-off device 58 Water vapor electrolyser 59 Cathode 60 Anode 62 Rectifier 63 Carrier gas line 64 Pressure and temperature measurement device 65 Flow rate measurement device 69 Pipe line 70 Shut-off device 71 Non-return device 72 Vacuum pump 73 Pressure line 75 Non-return device 76 Shut-return device 77 Hydrogen reservoir 78 Pressure control and alarm device 79 Blow-off line 80 shut-off valve 81 non-return device 82 blow-off valve 83 safety torch 84 bypass line 85 safety valve 86 compressor 88 air line 97 concentrate collection container 98 pipe line 99 pipe line 100 flow rate measuring device 101 pressure and temperature measuring device 102 pressure line 103 shut-off device 104 shut-off device 105 emergency relief line 106 emergency relief line 107 safety valve 108 safety valve 163 rectifier 164 pipe line 165 shut-off device 166 non-return device 167 vacuum pump 168 pressure line 169 non-return device 170 shut-off device 171 hydrogen storage 172 pressure regulating and alarm device 173 blow-off line 174 shut-off valve 175 non-return device 176 blow-off valve 177 safety torch 178 bypass line 179 safety valve 180 suction line 181 shut-off device 182 non-return device 183 vacuum pump 184 pressure line 185 pressure line 186 non-return device 187 shut-off device 188 oxygen storage 189 pressure regulating device 190 blow-off line 191 shut-off device 192 Non-return safety device 193 Blow-off valve 194 Bypass line 195 Safety valve 196 Oxygen pipeline 197 Non-return safety device 198 Shut-off device 199 Carrier gas line 248 Line 249 Pressure and temperature measurement device 250 Flow rate measurement device 262 Supply line 263 Flow rate measurement device 264 Regulating valve 265 Dialyzer 266 Cathode 267 Anode 269 Rectifier 270 Carrier gas line 271 Measurement device 272 Pipeline 273 Shut-off device 274 Non-return safety device 275 Vacuum pump 276 Pressure line 278 Non-return safety device 279 Shut-off device 280 Hydrogen reservoir 281 Pressure regulating and alarm device 282 Blow-off line 283 Shut-off device 284 Non-return safety device 285 Blow-off valve 286 Bypass line 287 Safety valve

Claims

Method for processing liquids, in which the liquid to be processed consists of a base liquid with substantially liquid and / or gaseous and / or salt-like impurities contained therein and / or dissolved therein, and in which a hot carrier gas stream laden with water vapor is present as a hot water vapor carrier gas stream, wherein the separation of the impurities from the base liquid is carried out in such a way that the liquid to be processed is fed as a processing liquid for preheating and prepurification to at least one preheating / separating device (7, 14), in which the processing liquid is preheated to a temperature below the boiling temperature of the base liquid, such that the liquid impurities having a low boiling point with respect to the base liquid evaporate and / or the gaseous impurities are thermally driven out, and the impurities thus evaporated and / or driven out are subsequently separated out, the processing liquid preheated and prepurified in this way is supplied to a carrier gas which is circulated in a closed circuit and this mixture is vaporized by supplying heat to a wet carrier gas-vapor mixture in such a way that the base liquid is vaporized and the liquid impurities having boiling temperatures above the boiling temperature of the base liquid remain as residual liquid fraction and / or the salts contained in the base liquid remain as salt sols, that this wet carrier gas-vapor mixture is supplied to a concentrate separator (30) in which the residual liquid fraction and / or the salt sols are separated as concentrate, that the carrier gas-vapor mixture which is freed from the residual liquid fraction and / or the salt sols and thus purified is compressed as a dry carrier gas-vapor mixture and then cooled, so that the base liquid is condensed and separated as a condensate in a downstream condensate separator (43) and, in addition, a hot carrier gas laden with uncondensed water vapor is present after the condensate separator (43), said carrier gas forming the hot water vapor carrier gas stream, characterized in that at least a partial stream of the hot water vapor carrier gas stream is subjected to a water vapor electrolysis in which at least a portion of the hydrogen and / or oxygen is split off from the hot water vapor carrier gas stream and a dried carrier gas stream is generated, wherein at least a partial amount of the dried carrier gas stream is fed to the liquid to be treated.Method according to Claim 1, characterized in that the hot water vapor carrier gas stream for water vapor electrolysis is conducted into a reaction space of a water vapor electrolyser (58; 265), in which at least one anode and at least one cathode are arranged as electrodes (59, 60; 266, 267), to which electrical energy is supplied by an energy supply device (62; 163; 269).Process according to Claim 1 or 2, characterized in that the entire hot water vapor carrier gas stream is fed to the water vapor electrolysis.Method according to Claim 1 or 2, characterized in that a quantity of the hot steam carrier gas stream which is predefined as a function of the gas drying degree and / or of the hydrogen demand and / or of the oxygen demand is fed to the steam electrolysis.Method according to Claim 4, characterized in that the quantity of hot water vapour carrier gas fed to the water vapour electrolysis is predetermined by means of a regulating device (264), by means of which a setting and / or measuring device (263) arranged in the feed line (262) to a water vapour electrolyser (265) and coupled to the regulating device (264) is actuated.Method according to one of Claims 1 to 5, characterized in that the dried carrier gas stream coming from the steam electrolysis is passed via at least one gas content measuring device (271), in which the content of hydrogen and / or oxygen in the dried carrier gas stream is determined.Method according to claims 5 and 6, characterised in that the oxygen and / or hydrogen loading of the dried carrier gas stream determined by means of the gas content measuring device (271) is supplied to the regulating device (264) as a parameter and the quantity of the hot water vapor carrier gas stream to be supplied to the water vapor electrolysis is determined at least as a function of this gas loading.Method according to one of Claims 1 to 7, characterized in that at least some of the hydrogen and / or oxygen obtained during the steam electrolysis is drawn off from the steam electrolyser (58; 265) and stored or buffer-stored in a gas store (77; 171, 188; 280).Method according to one of the preceding claims, characterized in that the treatment liquid preheated and to be treated in at least one preheating heat exchanger (7) of each preheating / separating device (7, 14) is fed to a flash device as a component of a separating device (14) of a preheating / separating device (7, 14), with which the low-boiling vaporous impurities and / or gaseous impurities are separated.Method according to one of the preceding claims, characterized in that each preheating heat exchanger (7) is a condensate / treatment liquid heat exchanger, with which preheating takes place by means of the hot condensate coming from a condensate collecting container (44).Method according to one of the preceding claims, characterized in that a further heat supply for preheating the treatment liquid in a concentrate / treatment liquid heat exchanger takes place through the hot concentrate coming from a concentrate collecting container.Method according to one of the preceding claims, characterized in that the treatment liquid is preheated in the at least one preheating heat exchanger (7) up to as close as possible to the evaporation temperature of the base liquid.Method according to one of the preceding claims, characterized in that at least some of the heat input for the evaporation to the wet carrier gas-steam mixture takes place in at least one evaporator / condensation heat exchanger (27) by the outflowing compressed purified carrier gas-dry steam mixture, which condenses in this at least one evaporator / condensation heat exchanger (27) at least partially by the heat emission.Method according to one of the preceding claims, characterized in that carrier gas is added and / or replenished from a connected carrier gas store for the starting process or in the event of a loss of carrier gas in the carrier gas circuit.Method according to claim 14, characterised in that in the case of air as carrier gas, the latter is sucked in from the environment.Device for processing liquids, in particular for carrying out a method according to one of the preceding claims, having at least one preheating / separating device (7, 14) for preheating and prepurifying the processing liquid, which device has in each case at least one preheating heat exchanger (7) and a separating device (14) connected downstream thereof, in such a way that the processing liquid can be preheated to a temperature below the boiling temperature of the base liquid by means of the preheating heat exchanger (7), and in that the liquid impurities, which are low in boiling point with respect to the base liquid, and / or the gaseous impurities can be separated off by means of the downstream separating device (14), having a mixing device (8) which is connected to the at least one preheating / separating device (7, 14) and in which the preheated and prepurified treatment liquid can be supplied with carrier gas which is guided in a closed circuit via a carrier gas line (63; 199; 270) in such a way that in the mixing device (8) a distribution of the treatment liquid in the carrier gas to form a carrier gas-treatment liquid mixture can be carried out, with at least one evaporator / condensation heat exchanger (27) connected downstream of the mixing device (8) for evaporating the carrier gas-treatment liquid mixture to form a wet carrier gas-vapor mixture in which the base liquid is evaporated and the liquid impurities having boiling temperatures above the boiling temperature of the base liquid remain as residual liquid fraction and / or the salts contained in the base liquid remain as salt sols, having a concentrate separator (30), which is connected downstream of the at least one evaporator / condensation heat exchanger (27), for separating the residual liquid fraction and / or the brine and also a carrier gas dry mixture from the wet carrier gas vapor mixture, having a condensate separator (43), which is connected downstream of the concentrate separator (30) and to which the carrier gas dry vapor mixture, after passing through the at least one evaporator / condensation heat exchanger (27) and condensing the base liquid there, can be fed, for separation, on the one hand, of the base liquid as condensate and, on the other hand, of a hot carrier gas stream, which is laden with water vapor, as a hot water vapor carrier gas stream, characterized in that a water vapor electrolyser (58 can be fed to the condensate separator (43), which provides the hot water vapor carrier gas stream; 265), to which at least one partial stream of the hot steam carrier gas stream can be fed and in which at least some of the hydrogen and / or oxygen is split off from the hot steam carrier gas stream and a dried carrier gas stream is generated, which can be fed to the mixing device (8) via the carrier gas line (63; 199; 270).Apparatus according to Claim 16, characterized in that a shut-off device (57) is arranged upstream of the water vapor electrolyser (58; 265), and in that at least one anode and at least one cathode are arranged as electrodes (59, 60; 266, 267) in the reaction space of the water vapor electrolyser (58; 265), said electrodes being coupled to an energy supply device (62; 163; 269).Device according to claim 17, characterised in that the gas occurring at the respective electrodes (59, 60; 266, 267) can be sucked off by means of a suction and / or pumping device (72; 167, 183; 275) via a pipe (69; 164, 180; 272) assigned to the respective electrode (59, 60; 266, 267).Device according to claim 18, characterised in that a shut-off device (70; 165, 181; 273) and / or a non-return device (71; 166, 182; 274) is arranged in the pipeline (69; 164, 180; 272) between the electrolyser (58; 265) and the suction and / or pump device (72; 167, 183; 275).Device according to claim 18 or 19, characterised in that a gas storage pipeline (73; 168, 184, 185; 276) is guided from the suction and / or pumping device (72; 167, 183; 275) to a gas storage device (77; 171, 188; 280), in which a shut-off device (76; 170, 187; 279) and / or a non-return device (75; 169, 186; 278) is furthermore arranged.Device according to claim 20, characterised in that the gas reservoir (77; 171, 188; 280) designed as a compressed gas reservoir is assigned a pressure regulating and / or alarm device (78; 172, 189; 281), which actuates an exhaust device (82; 176, 193; 285) as a function of a predetermined overpressure via a blow-off line (79; 173, 190; 282) which has a shut-off device (80; 174, 191; 283) and / or a non-return device (81; 175, 192; 284).Device according to claim 21, characterised in that the blowing device (82; 176, 193; 285) is bridged by means of a bypass line (84; 178, 194; 286) in which a mechanical safety valve (85; 179, 195; 287) is arranged.Device according to one of Claims 20 to 22, characterized in that a safety torch (83; 177; 283) in the blow-off line (79; 173; 282) is connected downstream of a hydrogen storage as gas storage means (77; 171; 280).Apparatus according to one of Claims 20 to 23, characterized in that an oxygen accumulator (188) as gas accumulator is assigned an oxygen pipe (196) with a shut-off device (198) and / or a non-return device (197), via which a predefined amount of oxygen can be fed into the dried carrier gas stream at predefined times by means of a control and / or regulating device.Device according to claim 24, characterised in that the oxygen pipe (196) branches off from the gas storage pipe (184, 185) and opens into the carrier gas pipe (199) carrying the dried carrier gas stream.Device according to one of Claims 16 to 25, characterized in that at least one measuring device (64, 65; 100, 101; 249, 250) for detecting the flow rate and / or the temperature and / or the pressure is arranged in the carrier gas line (63; 199; 270).Device according to one of Claims 16 to 26, characterized in that the hydrogen electrolyser (265) is preceded by a regulating device (264), by means of which a predefined amount of the hot steam carrier gas stream is fed to the steam electrolyser (265) as a function of the degree of gas drying and / or of the hydrogen demand and / or of the oxygen demand.Device according to claim 27, characterised in that a predetermined quantity of the hot water vapour carrier gas is guided via a measuring device (263) arranged in a feed line (262) to the water vapour electrolyser (265) and coupled to the regulating device (264).Device according to claim 27 or 28, characterised in that the carrier gas line (270) branches off from the electrolyzer (265), to which at least one gas content measuring device (271) is assigned.Apparatus according to one of Claims 16 to 29, characterized in that the separating device (14) of each preheating / separating device (7, 14) has a decompression device, which is connected downstream of the preheating heat exchanger (7), for separating vapour impurities of low boiling point with respect to the base liquid and / or gaseous impurities.Device according to claim 30, characterised in that the expansion device is formed by an expansion container (14) with an associated pump (21) or by a pervaporation membrane plant.Device according to one of Claims 16 to 31, characterized in that each preheating heat exchanger (7) is formed by a condensate / treatment liquid heat exchanger and / or in that, for a further heat supply for preheating the treatment liquid, a concentrate / treatment liquid heat exchanger is connected upstream of the at least one preheating / separating device (7, 14).Device according to one of Claims 16 to 32, characterized in that at least one subregion of a feed line from the concentrate separator (30) to the condensate separator (43) is designed as a carrier gas-dry steam mixture pressure line (37) with an upstream compressor (36) for increasing the pressure and temperature of the carrier gas-dry steam mixture, wherein at least one flow measuring device and / or at least one temperature measuring device and / or at least one pressure measuring device which is or are part of a control circuit is arranged in the pressure line (37) for operating monitoring.

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