DE102018106521A1 - Plant for separating an aqueous solution into purified water and solution residues - Google Patents

Abstract

A plant (10) for separating an aqueous solution (14) into water and dissolution residues (59) is characterized by a one-stage or multi-stage high pressure reverse osmosis unit (12) for separation in view of enabling such separation with comparatively low energy requirements the solution (14) in a permeate (16) and a concentrate (18) and a high-pressure reverse osmosis unit (12) upstream single-stage or multi-stage pump unit (20) for supplying the solution (14) in the high-pressure reverse osmosis unit (12) below Pressure, wherein at the concentrate (18) from the last stage of the high-pressure reverse osmosis unit (12) laxative output line (26) comprises a turbine unit (28) with a driven thereby generator (30) for converting the pressure energy of the concentrate (18) into electrical Energy (32) is arranged and wherein the generator (30) an energy conversion unit (34) is connected downstream, which verbu electrically with the pump unit (20) Nden is that by the means of the generator (30) obtained electrical energy (32), the pump unit (20) is drivable.

Description

The invention relates to a system for separating an aqueous solution into water and solution residues having the features of the preamble of claim 1.

Systems for separating an aqueous solution into water and solution residues are known from the prior art, for example DE 10 2015 210 910 A1 , With the plant proposed there, a dehydration of aqueous solutions is possible, which can be achieved by the series connection of several membrane units before feeding the solution to a thermal separation unit high dewatering rates. Although the energy demand of such a system is reduced compared to conventional systems, there is still room for optimization in terms of energy requirements.

The invention has for its object to enable separation of an aqueous solution in water and residues with relatively low energy consumption. In order to increase profitability, in particular a reduction of the primary energy demand required for plant operation is desirable.

The invention solves this problem with a system having the features of claim 1. Thereafter, the system is characterized by a single-stage or multi-stage high-pressure reverse osmosis unit for separating the solution into a permeate and a concentrate and the high-pressure reverse osmosis unit upstream single-stage or multi-stage pump unit for supplying the solution into the high-pressure reverse osmosis unit under (elevated) pressure, wherein at the outlet line discharging the concentrate from the last stage of the high-pressure reverse osmosis unit, a turbine unit with a generator driven or driven thereby for converting the pressure energy of the concentrate into electrical energy is arranged and wherein the generator is followed by an energy conversion unit (electrical connection between the generator and the energy conversion unit), which is electrically connected to the pump unit in such a way that the electrical energy obtained by means of the generator causes the Pu mpeneinheit driven or driven.

Such an embodiment has the advantage that the profitability of the plant described can be increased to a considerable extent, since the energy fed into the solution by way of reverse osmosis can be recovered to a high proportion. This reduces the primary energy required for plant operation. This is done by converting the pressure energy contained in the concentrate by the turbine unit together with the generator after passing through the high-pressure reverse osmosis unit into electrical energy and supplied by means of the energy conversion unit to the pump unit, where the recovered energy is used to drive the pump unit (drive of the pump motor or motors) can be. A recovery potential of about 20 to 40 percent of the feed-in energy can be realized. By using the energy conversion unit, a decoupling of the volume flows before and after the high-pressure reverse osmosis unit is made possible, since the volume flows are not positively coupled, such as in the case of a mechanical coupling.

Specifically, this plant may be a drainage plant. In this plant, an aqueous solution can be supplied via an inlet, for example. A high saline solution. The process results can be on the one hand water, preferably purified water, and on the other hand solution residues, for example. Final concentrate or solid.

The single-stage or multi-stage pump unit is used to increase the pressure of the supplied solution to a pressure above the atmospheric pressure level, for example. To a pressure of about 5 bar. The pump unit may be one or more pre-pressure pumps or feed pumps. The pump unit has one or more electric motors for driving the pump unit.

The high-pressure reverse osmosis unit can be designed in one or more stages. The high-pressure reverse osmosis unit can have a plurality of modules, for example tubular-plate modules and / or ultra-high-pressure-wound modules.

The system and in particular the high-pressure reverse osmosis unit are preferably set up such that an operating range above the previous system pressures of about 100 bar (conventional seawater desalination) can be achieved. In particular, system pressures of 100 to 200 bar should be achieved. Possible operating pressures may be 100 bar, 120 bar, 140 bar, 160 bar, 180 bar and / or 200 bar (pressure in the high pressure reverse osmosis unit). In this case, the plant and in particular the high-pressure reverse osmosis unit are designed to promote low volume flows (about 5 to 120 m3 / h) at high operating pressures.

In a preferred embodiment, the energy conversion unit can be set up such that the proportion of the electrical energy supplied to the pump unit (proportion of the recovered energy) can be regulated. Thus, the recovered energy can partially or completely to drive The pump unit can be used, with utilization rates of 0 to 100 percent are conceivable. As a result, the volume flows before and after the high-pressure reverse osmosis unit can be decoupled. A regulation of the volume flows relative to each other is possible, in particular by controlling the supply of the recovered and supplied to drive the pump unit energy. This makes it possible to realize variable volume flows, in particular as a function of the dissolved salt content. It is essential that the energy conversion unit is designed adjustable. However, the specific design of the energy conversion unit may look different. For example. The energy conversion unit may comprise one or more transformers, one or more voltage and / or current transformers, one or more inverters and / or one or more rectifiers.

In an advantageous manner, the energy conversion unit can have an electrical energy store or interact with an electrical energy store. As a result, excess recovered electrical energy can be stored and retrieved at a later time. The energy conversion unit is in particular configured to cooperate with the electrical energy store, for example by an electrical interface to the energy conversion unit for coupling to the energy store. The electrical energy store may in particular be an electrochemical energy store, for example a battery or a rechargeable battery.

Conveniently, an external electrical power supply can be provided which can supply or supply the energy conversion unit with energy. By an external electrical, for example, grid-connected, energy source, the energy conversion unit can be supplied alternatively or supplementarily with electrical energy, so that, for example, load peaks can be energetically covered. For this purpose, the energy conversion unit can be set up for an external electrical energy supply, for example by an interface for the external electrical energy supply.

Within the scope of a preferred embodiment, a photovoltaic system can be provided which can supply or supply the energy conversion unit and / or the electrical energy store with electrical energy. In this way, further energy optimization is possible because the proportion of primary energy can be further reduced. The energy conversion unit and / or the electrical energy store can have corresponding electrical interfaces for interaction with the photovoltaic system.

Advantageously, the turbine unit at the output line, in particular with the interposition of a concentrate batch storage, an evaporation plant and a heat exchanger to be followed, which at least a portion of the (relaxed) concentrate is supplied. This allows further dewatering of the concentrate.

The concentrate fed to the evaporation unit and the heat exchanger, if necessary with the interposition of a concentrate wipe accumulator, has "relaxed" to a lower pressure, since this has already passed through the turbine unit (low-pressure side concentrate). Before passing through the turbine unit, the concentrate is still under pressure (concentrate high-pressure side).

Conveniently, a mechanical vapor compressor can be provided, which cooperates with the evaporation plant and / or the heat exchanger. As a result, at least some of the energy contained in the vapor of the evaporation plant can be recovered and fed back to the evaporation plant at a higher temperature and thus at a higher energy level. In particular, vapor can be supplied to the vapor compressor via a steam supply line from the evaporation plant. There, the steam can be raised by means of the mechanical vapor compressor, for example a blower, to a higher temperature and thus also a higher energy level. Via a steam return line, the compressed steam can be supplied to the heat exchanger, for example a heat exchanger, which supplies this energy to the evaporation plant as heat. By the vapor compressor only the energy required for increasing the temperature must be applied, which may, for example, at least partially originate from the electrical energy storage.

In a preferred embodiment, a further energy conversion unit can be provided, by means of which the vapor compressor electric energy of the energy storage or another external electrical power supply is supplied to drive the vapor compressor. Thus, the drive energy for the drive of the vapor compressor can be applied at least partially from recovered electrical energy. The further energy conversion unit is set up such that it can interact with the electrical energy store, the further external electrical energy supply and / or the vapor compressor, for example. The further energy conversion unit can have corresponding electrical interfaces.

Advantageously, the turbine unit in the output line downstream of a concentrate disposal.

This allows disposal of the still liquid concentrate done, for example. By a storage lake or a solar panel. As a result, evaporation of the residual liquid still contained in the concentrate can be carried out, so that only solution residues, for example solids, remain behind.

Specifically, after passing through the turbine unit, a portion of the concentrate (concentrate low pressure side) of the evaporation system can be supplied, possibly after passing through concentrate batch and / or evaporation, and another part can be supplied to the concentrate disposal.

The system may have an inlet for supplying an aqueous, in particular high salt content (> 3.5 grams of salt per liter of solution) solution to the pump unit. The pump unit may be fluidly connected to the high pressure reverse osmosis unit via an input line. The high-pressure reverse osmosis unit may be flow-connected to the turbine unit by means of the above-described outlet line (first section of the outlet line). The turbine unit may be fluidly connected to the evaporation plant and to the concentrate discharge by means of the described outlet line (second section of the outlet line).

• 1 ein Ausführungsbeispiel einer Anlage zum Trennen einer wässrigen Lösung in Wasser und Lösungsrückstände in einem Prinzipschaubild.

The invention will be explained in more detail with reference to FIGS. It shows:

• 1 an embodiment of a system for separating an aqueous solution in water and solution residues in a schematic diagram.

1 shows a plant for separating an aqueous, in particular saline-containing, solution in preferably purified water and residues of the solution, the plant as a whole by the reference numeral 10 is designated.

The attachment 10 has a single-stage or multi-stage high pressure reverse osmosis unit 12 for separation of the solution 14 into a permeate 16 and a concentrate 18 on. The permeate 16 represents part of the solution 14 recovered water, which may be further processed, for example, can be cleaned.

The high-pressure reverse osmosis unit 12 is a single-stage or multi-stage pump unit 20 for supplying the solution 14 into the high pressure reverse osmosis unit 12 upstream under increased pressure. The pump unit 20 is by means of an input line 22 with the high-pressure reverse osmosis unit 12 flow-connected. About a feed 24 becomes the solution 14 the pump unit 20 fed.

The attachment 10 has an output line 26 on, with the concentrate 18 from the last stage of the high pressure reverse osmosis unit 12 is discharged (first section of the output line 26 ). At the output line 26 is a turbine unit 28 with a generator driven thereby 30 for converting the pressure energy of the concentrate into electrical energy 32 arranged. The generator 30 is an energy conversion unit 34 connected downstream with the pump unit 20 electrically connected such that by means of the generator 30 gained electrical energy 32 the pump unit 20 is driven or driven.

Before the concentrate 18 the turbine unit 28 passes through, stands the concentrate 18 under pressure (concentrate high pressure side 31 ). After the concentrate 18 the turbine unit 28 has gone through, the concentrate has become 18 relaxed to a lower pressure (concentrate low pressure side 33 ).

The energy conversion unit 34 is set up so that the proportion of the pump unit 20 supplied electrical energy is controllable. The concrete design of the energy conversion unit 34 may vary, as described above.

Optionally, the energy conversion unit 34 an electrical energy storage 36 on or acts with an electrical energy storage 36 together. The energy conversion unit 34 can have one or more electrical interfaces 38 have to with the electrical energy storage 36 co.

It is also conceivable (optional) that an external electrical power supply 40 is provided, which is the energy conversion unit 34 supplied with electrical energy. The energy conversion unit 34 can be an appropriate interface 42 have to deal with the external electrical power supply 40 co.

Optionally, a photovoltaic system 44 be provided, which is the energy conversion unit 34 and / or the electrical energy storage 36 supplied with electrical energy. For this purpose, the energy conversion unit 34 and the electrical energy storage 36 corresponding electrical interfaces 38 . 46 exhibit.

The turbine unit 28 is at the output line 26 (second section of the output line 26 ), in particular with the interposition of a concentrate cache 48 , an evaporation plant 50 and a heat exchanger 52 downstream, which at least a part of the relaxed concentrate 18 (Concentrate of the low pressure side 33 ) is supplied. The output line 26 is over line sections 51 with the concentrate cache 48 , the heat exchanger 52 and / or the evaporation plant 50 connected.

Next is a mechanical vapor compressor 54 provided with the evaporation plant 50 and the heat exchanger 52 interacts. The vapor compressor 54 can via a steam supply line 56 Steam from the evaporation plant 50 be supplied. There, the steam can by means of the mechanical vapor compressor 54 , For example, a fan, be raised to a higher temperature and thus a higher energy level. Via a steam return line 58 the compressed steam can be the heat exchanger 52 , For example, a heat exchanger, are supplied to the evaporation plant 50 re-energize this energy as heat.

The heat exchanger 52 has an exit 53 on, on the condensate 55 can be removed. The condensate 55 represents part of the solution 14 recovered water, which can be further processed, for example, can be cleaned. The evaporation plant 50 has an exit 57 on, on the solution residues 59 can be removed, for example. Final concentrate or solid.

Optionally, another energy conversion unit 60 Be provided by means of the vapor compressor 54 electrical energy of the energy storage 36 or another external electrical power supply 62 to drive the vapor compressor 54 is supplied. The further energy conversion unit 60 can electrical interfaces 64 . 66 have to with the energy storage 36 and the external electrical power supply 62 co.

The turbine unit 12 can in the output line 26 a concentrate disposal 68 be downstream, which is formed, for example, as a storage lake or as a solar panel. This can be in the concentrate 18 remaining liquid remaining evaporate, so that only solution residues, for example solids, remain behind.

The attachment 10 for separating an aqueous solution 14 in preferably purified water works as follows:

At the inlet 24 is aqueous, especially high-salt solution 14 the pump unit 20 fed. The pump unit 20 brings the solution 14 to a pressure level above the atmospheric pressure, for example a pressure of about 5 bar. Subsequently, the pressurized solution 14 over the input line 22 the high-pressure reverse osmosis unit 12 fed. There is a reverse osmosis, in which the solution 14 into a permeate 16 and a concentrate 18 is separated. The liquid permeate 16 , which can be further purified or filtered, forms part of the recovered water.

The concentrate 18 is via an output line 26 from the high pressure reverse osmosis unit 12 discharged (concentrate high pressure side 31 ) and a turbine unit 28 with generator 30 fed (first section of the output line 26 ). The concentrate 18 contained pressure energy is at the turbine unit 28 by means of the generator 30 into electrical energy 32 converted by means of an energy conversion unit 34 for driving the pump unit 20 can be used. This will be described below.

After passing through the turbine unit 28 has the concentrate 18 to a lower pressure "relaxed" (concentrate low pressure side 33 ). At the low pressure side 33 (second section of the output line 26 ) may be a part of the concentrate 18 a concentrate disposal 68 be fed, for example, a storage lake or a solar panel, where in the concentrate 18 contained residual liquid can evaporate, so that only solution residues, eg. Solid remains.

At the low pressure side 33 may be another part of the concentrate 18 , if necessary via a concentrate cache 48 , via a heat exchanger 52 an evaporation plant 50 be supplied. The heat exchanger 52 has an exit 53 on, in the heat exchanger 52 condensed liquid as condensate 55 can be removed. The condensate 55 represents part of the aqueous solution 14 recovered water.

The concentrate 14 is from the heat exchanger 52 an evaporation plant 50 fed. The evaporation plant 50 has an exit 57 on, on the solution residues 59 , For example, final concentrate or solid, can be removed. The in the evaporation plant 50 contained steam is via a steam supply line 56 a mechanical vapor compressor 54 fed, which compresses the steam and thus raises to a higher temperature and energy level. Via a steam return line 58 the compressed steam becomes the heat exchanger 52 supplied, from where the heat energy of the evaporation plant 50 can be supplied.

As previously explained, can by the generator 30 those in the concentrate 18 contained pressure energy into electrical energy 32 being transformed. The electrical energy 32 can at least proportionately via an energy conversion unit 34 the pump unit 20 be supplied, where the electrical energy for feeding the drive or the pump unit 20 can serve. The Power conversion unit 34 can change the proportion of the pump unit 20 regulate recycled energy. Via an external electrical power supply 40 can the energy conversion unit 34 via their interface 42 be supplied with additional electrical energy, for example, to cover peak loads.

Recovered electrical energy 32 not to drive the pump unit 20 is needed, via appropriate interfaces 38 the electrical energy storage 36 be supplied. There can be electrical energy 32 stored and retrieved at a later date. About a photovoltaic system 44 can the electrical energy storage 36 via an interface 46 be supplied with additional electrical energy.

About another energy conversion unit 64 can electrical energy of the energy store 36 the mechanical vapor compressor 54 be supplied. Thus, to drive the mechanical vapor compressor 54 required electrical energy at least partially from the electrical energy storage 36 be fed. About another external electrical energy supply 62 can the further energy conversion unit 64 via their interface 66 further electrical energy are supplied, which also drive the mechanical vapor compressor 54 can be used.

In summary, the proposed plant has the advantage that its profitability is significantly increased, since about 20-40% of the feed-in energy can be recovered. By the electrical coupling of the turbine unit 28 with generator 30 about the energy conversion unit 34 with the pump unit 20 are the volume flows before and after the high-pressure reverse osmosis unit 12 decoupled from each other. Thus, variable volume flows can be realized, in particular depending on the dissolved salt content.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015210910 A1 [0002]

Claims (9)

Plant (10) for separating an aqueous solution (14) into water and dissolution residues (59), characterized by a single-stage or multi-stage high-pressure reverse osmosis unit (12) for separating the solution (14) into a permeate (16) and a concentrate (18 and a high-pressure reverse osmosis unit (12) upstream single-stage or multi-stage pump unit (20) for supplying the solution (14) in the high pressure reverse osmosis unit (12) under pressure, wherein at which the concentrate (18) from the last stage of the high pressure Reverse osmosis unit (12) discharging output line (26) a turbine unit (28) is driven therewith with a generator (30) for converting the pressure energy of the concentrate (18) into electrical energy (32) and wherein the generator (30) an energy conversion unit ( 34) which is electrically connected to the pump unit (20) in such a way that the pump unit (20) is energized by the electrical energy (32) obtained by means of the generator (30) ) is drivable. Appendix (10) to Claim 1 , characterized in that the energy conversion unit (34) is arranged such that the proportion of the pump unit (20) supplied electrical energy (32) is controllable. Appendix (10) to Claim 1 or 2 , characterized in that the energy conversion unit (34) has an electrical energy store (36) or cooperates with an electrical energy store (36). Plant (10) according to one of the preceding claims, characterized in that an external electrical energy supply (40) is provided, which can supply the energy conversion unit (34) with electrical energy. Plant (10) according to one of the preceding claims, characterized in that a photovoltaic system (44) is provided, which can supply the energy conversion unit (34) and / or the electrical energy store (36) with electrical energy. Plant (10) according to one of the preceding claims, characterized in that the turbine unit (28) at the output line (26), in particular with the interposition of a concentrate wedge memory (48), an evaporation plant (50) and a heat exchanger (52) are connected downstream of which at least a portion of the concentrate (18) is supplied. Appendix (10) to Claim 6 , characterized in that a mechanical vapor compressor (54) is provided, which cooperates with the evaporation plant (50) and / or the heat exchanger (52). Appendix (10) to Claim 7 , characterized in that a further energy conversion unit (64) is provided, by means of which the vapor compressor (54) electrical energy of the energy store (36) or another external electrical power supply (62) for driving the vapor compressor (54) is supplied. Plant (10) according to one of the preceding claims, characterized in that the turbine unit (28) in the output line (26) is followed by a concentrate disposal (68).

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