EP3237802A1

EP3237802A1 - Device and method for thermal exhaust gas cleaning

Info

Publication number: EP3237802A1
Application number: EP15813330.6A
Authority: EP
Inventors: Martin Schröter; Erhard Rieder
Original assignee: Duerr Systems AG
Current assignee: Duerr Systems AG
Priority date: 2014-12-22
Filing date: 2015-12-15
Publication date: 2017-11-01
Also published as: CN107407483A; US10429066B2; AU2015371529A1; AU2015371529B2; DE102015205516A1; US20170276347A1; WO2016102231A1

Abstract

A thermal exhaust gas cleaning device has at least one thermal reactor (10) to which a raw gas that is to be cleaned is supplied, and in which the supplied raw gas is thermally cleaned, and an energy recovery apparatus to which a gas cleaned in the thermal reactor is supplied via at least one discharge line (28, 34). In order to improve the energy balance, it is proposed that the energy recovery apparatus has at least one condensing heat exchanger (38, 50, 60, 64) in which the cleaned gas is cooled such that condensable materials contained in the cleaned gas condense, and enthalpy thus released is given off to a heat-exchange medium and/or the raw gas upstream of the thermal reactor (10).

Description

Apparatus and method for thermal exhaust gas purification

The present invention relates to an apparatus and a method for thermal exhaust gas cleaning, in particular for cleaning a mine exhaust gas or a mine exhaust air, especially a methane-containing mine ventilation gas. However, the present invention can also be used for the thermal cleaning of other flammable or exhaust gases containing combustible constituents, in particular volatile organic components (VOCs).

It is known to use a thermoreactor for purifying mine exhaust gases, especially methane-containing mine ventilation gases (VAM), and to supply the hot gas resulting from the thermal oxidation process to an energy recovery device. For example, CN 102733872 A proposes to use the heat energy of the hot gas to produce or further heat water vapor used to drive a steam turbine coupled to a generator for generating electrical power.

The inventors have recognized that the energy efficiency of this process, as well as many other heat exchange processes, is limited by the exclusive use of the gross calorific value or the enthalpy difference between a heat exchange entry temperature and a heat exchange exit temperature. In many cases, the use of the calorific value (lower calorific value) of fuels or the general use of the condensation energy of moist constituents of the (waste) gas is limited by the operating conditions of the secondarily generated energy form. This also applies, for example, to the generation of steam in the boiler operation of a power generation process.

Conventional processes (see, for example, CN 102733872 A) use the enthalpy difference of a hot gas stream heated by an upstream process to produce steam in boiler operation. Are such hot gas streams in a combustion process of

Hydrocarbons generate or contain these for another reason larger Quantities of condensable components, such as in a methane-containing mine ventilation gas, the condensation enthalpy is not used. In the case of larger amounts of water vapor in the gas stream, on the contrary, a disproportionately large amount of the enthalpy inherent in the hot gas stream is bound in the form of enthalpy of vaporization and thus removed or not supplied to the energy transfer in the boiler.

The invention has for its object to provide an improved apparatus and an improved method for thermal exhaust gas purification, which have an improved energy balance.

This object is achieved by the teaching of the independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

The device according to the invention for thermal exhaust gas purification has a thermal reactor to which a raw gas to be purified can be supplied and in which the raw gas supplied is thermally cleanable, and an energy recovery device to which a gas purified in the thermoreactor can be supplied via at least one discharge line. The energy recovery device in turn has at least one condensation heat exchanger in which the purified gas can be cooled in such a way that condensable substances contained in the purified gas condense and enthalpies released in this way can be released to a heat exchange medium and / or the raw gas upstream of the thermoreactor.

Preferably, the thermoreactor has a combustion chamber in which the raw gas supplied is thermally cleanable. The energy recovery device is preferably connected to the combustion chamber of the thermoreactor via a discharge line in order to supply the energy recovery device with a purified gas produced during the thermal cleaning process in the combustion chamber. Furthermore, the energy recovery device preferably has a further heat exchanger in which the purified gas can be cooled to a first temperature level and an enthalpy released in this way can be delivered to a heat exchange medium, and the condensation heat exchanger downstream of the other Heat exchanger is arranged and in which the purified gas to a second temperature level lower than the first temperature stage is further cooled, so condense contained in the purified gas condensables, and released enthalpies to a heat exchange medium and / or the raw gas upstream of the thermoreactor can be issued , on.

Preferably, the thermoreactor is a thermal oxidation reactor, which is preferably designed for regenerative thermal oxidation (RTO) and exemplified in WO

2008/011965 AI the applicant is described, the content of which in this respect is fully made the subject of the present invention. The thermoreactor may in this context, in particular a RTO reactor with two, three, four or more

Be regenerators or containers.

The inventive method for thermal exhaust gas purification includes the steps of thermal cleaning of a raw gas to be purified in a thermoreactor; and cooling a purified gas resulting from the thermal purification process in the thermoreactor in a condensation heat exchanger to condense condensables contained in the purified gas, releasing released enthalpies to a heat exchange medium and / or the raw gas upstream of the thermoreactor.

Preferably, the thermal cleaning of the raw gas takes place in a combustion chamber of the thermoreactor. The purified gas produced in the thermal combustion process in the combustion chamber is preferably in a further heat exchanger to a first

Cooled temperature level, wherein a released enthalpy is delivered to a heat exchange medium. Further, the purified gas is preferably further cooled in the condensation heat exchanger downstream of the further heat exchanger to a second temperature level lower than the first temperature stage, so that condense condensables contained in the purified gas, and released enthalpies to a Heat exchange medium and / or the raw gas are discharged upstream of the thermoreactor.

Preferably, the thermal cleaning of the raw gas takes place in a thermal

Oxidation reactor, which is preferably designed for regenerative thermal oxidation (RTO) and described by way of example in WO 2008/011965 AI the applicant, the content of which in this respect is fully made the subject of the present invention. The thermoreactor may in this context be in particular an RTO reactor with two, three, four or more regenerators or containers.

According to a preferred embodiment of the invention, in a first heat exchanger (further heat exchanger of the invention) of the energy recovery device, an enthalpy difference between the inlet temperature and the outlet temperature (first temperature step of the invention) of the purified hot gas into and out of the first heat exchanger can be utilized. In addition, in the second heat exchanger

(Condensation heat exchanger of the invention) of the energy recovery device by condensation of the moisture in the hot gas and the inherent enthalpy of the hot gas evaporation are used. In this way, depending on the type of condensing second heat exchanger, for example about 60-70% of the temperature difference between the outlet temperature of the hot gas from the first heat exchanger and the condensation temperature of the moisture (typically water vapor) and the enthalpy of vaporization can be transferred to the heat exchange medium.

The thermal cleaning process should in this context include all types of cleaning processes in which heat energy is supplied to the raw gas to be purified. These include, in particular, thermal oxidation processes of combustible substances contained in the raw gas to be purified.

In this context, the discharge line comprises, in particular, a so-called clean gas line, through which the gases purified in the thermoreactor, after flowing through the Regenerators with appropriate cooling (to eg about 70 ° C) are discharged as so-called clean gas from the thermoreactor, and a so-called hot gas line, through which the cleaned gases in the thermoreactor after thermal cleaning in the thermoreactor with appropriate heating (for example, about 1,000 ° C) are discharged as so-called hot gas from the combustion chamber of the thermoreactor. Accordingly, the purified gas in this context comprises in particular the so-called clean gas and the so-called hot gas.

According to the invention, in the condensation heat exchanger of the energy recovery device "contained in the purified gas condensable substances

For the purposes of the invention, this should also be understood as meaning that at least one condensable substance component comprising the purified gas condenses at least partially in the condensation heat exchanger According to the invention, it is in particular proposed that the energy latently contained in the (raw) gas in the form of relative humidity should also be determined by means of an RTO reaction. This approach is based in particular on the following considerations: The raw gas to be supplied to the exhaust gas purification system can be used in the reactor downstream of the condensation heat exchanger, thus improving the energy balance of the entire process n in addition to gaseous components also contain a significant amount of moisture (in the form of condensable substances). It can the

Proportion of moisture components before entering the post-combustion plant

Due to a decrease in temperature between the raw gas source and entry into the post-combustion system, parts of the vapor begin to condense out or can condense. However, the resulting small liquid droplets are entrained by the high flow velocity of the crude gas stream and thus get into the Thermal reactor. There, a portion of the stored heat in the regenerator of the thermal reactor is expended to re-evaporate the liquid, so that this proportion is initially not available for heating the raw gas and to initiate the oxidation reactions available. This latently stored heat is also delivered to the heat storage mass on exit via the output-side regenerator of the thermoreactor, so that the overall thermal reactor can not work with optimum efficiency. The invention according to the thermoreactor downstream condensation heat exchanger now uses this latent heat stored, so that the overall efficiency of the system can be recycled with moist, vapor-saturated crude gases to a level that corresponds to that typical TNV plants in the implementation of substantially arid raw gases. That is, the present invention is particularly advantageous for use in processes in which the crude gas supplied to the thermoreactor contains liquid droplets, but without being limited to this application. In a preferred embodiment of the invention, the further heat exchanger and the condensation heat exchanger are in heat exchange with a common heat exchange medium circuit. In this case, the condensation heat exchanger in the common heat exchange medium circuit is preferably arranged upstream of the further heat exchanger, and the heat exchange medium of the common heat exchange medium circuit can preferably be preheated in the condensation heat exchanger.

In another preferred embodiment of the invention, the further heat exchanger is in heat exchange with a first heat exchange medium circuit and is the

Condensation heat exchanger with a second, separate from the first heat exchange medium circuit heat exchange medium circuit in heat exchange.

Condensation heat exchanger with a Rohgaszuführleitung upstream of the thermoreactor in heat exchange. In yet another preferred embodiment of the invention is in the common heat exchange medium circuit downstream of the further heat exchanger another

Condensation heat exchanger provided, which is in heat exchange with a Rohgaszuführleitung upstream of the thermoreactor.

The term circulation in this context should include both closed and open circuits. In a preferred embodiment of the invention, a power generating device is arranged in the common heat exchange media circuit or the first heat exchange medium circuit downstream of the further heat exchanger. That the heated in the further heat exchanger heat exchange medium is preferably used to generate electricity. The power generating device preferably has a steam turbine connected to the circuit and a generator coupled to the steam turbine for generating electric power.

In a further preferred embodiment of the invention, at least one hot and / or hot water consumer and / or a district heating connection are arranged in the second heat exchange medium circuit downstream of the condensation heat exchanger. In other words, the heat exchange medium of the second heat exchanger is preferably a process water or a heating medium. Alternatively, it can also be provided that the second heat exchange medium circuit serves as a heat source for the operation of an ORC system. In this case, either an intermediate medium, for example a thermal oil, may be provided for heat transfer to an ORC plant in the second heat exchange medium cycle or, alternatively, the second heat exchange medium cycle may be a working medium cycle of an ORC plant, the second heat exchanger acting as an evaporator for a working medium ORC plant can work. In a further preferred embodiment of the invention, a condensate produced in the condensation heat exchanger of the energy recovery device can be returned to the process via condensate removal. For example, the condensate may be supplied to a heat exchange medium circuit as a heat exchange medium.

In another preferred embodiment of the invention, the condensation heat exchanger of the energy recovery device transfers the residual and / or condensation enthalpy to the raw gas stream to be treated, especially methane-containing mine ventilation gas (VAM), before it enters the thermoreactor. In this variant, small amounts of drops contained in the crude gas stream can be evaporated. In addition, the thermoreactor correspondingly more energy for primary energy recovery in the other heat exchanger can be withdrawn. In another, alternative or supplementary embodiment of the invention utilizes the

Condensation heat exchanger of the energy recovery device, the residual and / or condensation enthalpy of the (regenerative) thermoreactor via a clean gas discharge line effluent, purified clean gas flow as a heat source and transfers them to a heat exchange medium in the second heat exchange medium cycle. This variant can be particularly advantageous if an outlet temperature of the clean gas flow in the

Clean gas discharge line is above the dew point of a vapor component in the exhaust stream, in particular min. 80 ° C, preferably min. 90 ° C, preferably min. 100 ° C or higher. Alternatively it can also be provided that both the exhaust gas flow from the clean gas discharge line and the hot gas leaving the further heat exchanger are supplied to the condensation heat exchanger as heat source for heat transfer to the heat medium in the second heat exchange medium cycle.

In further variants can also be provided that the energy recovery device in addition to the aforementioned heat exchangers in a sequential arrangement in the hot gas line also a further heat exchanger for condensation of moisture having the pure gas flowing out in the clean gas line, so that the enthalpy of vaporization inherent in this clean gas is also usable. This variant can be particularly advantageous if an outlet temperature of the (cooler) clean gas flow in the clean gas line is above the dew point of a vapor component in the exhaust gas stream, in particular min. 80 ° C, preferably min. 90 ° C, preferably min. 100 ° C or higher.

The apparatus of the invention described above and the method of the invention described above can be used in a particularly advantageous manner for cleaning a mine exhaust gas, in particular a methane-containing mine ventilation gas (VAM). The ventilation air of coal mines is admixed with moisture of the order of, for example, 30 to 35% by volume in order to reduce the formation of underground dust during the intake process. The invention utilizes the enthalpy of this moisture in the effluent of the thermoreactor in energy recovery. In particular, the following advantages can be achieved with the invention described above:

Use also the enthalpy of evaporation of the moisture contained in the purified gas, in particular in the hot gas (-> improvement of the energy balance);

Minimization of water consumption by recycling the condensate in the circuit containing the other heat exchanger or another process (->

Improvement of the resource balance);

Increase the performance of the other heat exchanger with the same energy and / or fuel consumption;

Minimizing CO 2 emissions of the energy producing process upstream of the energy recovery device;

improved energy balance, in particular for raw gases containing liquid droplets; Achieving a dryer exhaust air flow from the emission control device. The above and other advantages, features and applications of the invention will become more apparent from the following description of various embodiments with reference to the accompanying drawings. Show:

Fig. 1 is a schematic representation of the construction of a thermal exhaust gas purification device according to a first embodiment of the invention;

Fig. 2 is a schematic view of the structure of a thermal exhaust gas purification device according to a second embodiment of the invention;

FIG. 3 is a schematic view of the structure of a thermal exhaust gas purification device according to a third embodiment; FIG.

FIG. 4 is a schematic view of the structure of a thermal exhaust gas purification device according to a fourth embodiment; FIG.

Fig. 5 is a schematic view of the structure of a thermal exhaust gas purification device according to a fifth embodiment;

FIG. 6 is a schematic diagram of the structure of a thermal exhaust gas purification device according to a sixth embodiment; FIG.

Fig. 7 is a schematic representation of the structure of a thermal exhaust gas purification

Device according to a seventh embodiment; and

Fig. 8 is a schematic representation of the structure of a thermal exhaust gas purification

Device according to an eighth embodiment.

Fig. 1 shows a system for purifying a methane-containing mine ventilation gas (VAM) according to a first embodiment of the present invention. In addition to the components described below and illustrated in the drawing, the system illustrated in FIG. 1 also has, in particular, numerous (control) valves and sensors (in particular temperature sensors) which have been omitted for the sake of simplicity, but which are described, for example, in WO 2008/011965 AI are known.

The thermal emission control device of FIG. 1 includes a thermal reactor 10 for regenerative thermal oxidation (RTO) of combustibles in an exhaust or exhaust stream. The thermoreactor 10 has a combustion chamber 12 and two regenerators 14 arranged below the combustion chamber 12, each of which comprises an antechamber and a heat storage mass chamber arranged above the prechamber. In the embodiment shown, the thermoreactor 10 has two regenerators 14, but in other embodiments, three, four or more regenerators 14 may be provided below the combustion chamber 12.

In the combustion chamber 12 of the thermal reactor 10 projects a burner 16, which are supplied via a gas supply 18 fuel gas and combustion air. The burner 16 serves to burn the pollutants (e.g., methane) contained in the raw gas to be purified. During operation, the temperature in the combustion chamber 12 can be up to about 1000 ° C., depending on the energy content of the combustible substances contained in the raw gas.

The pre-chamber of each regenerator 14 of the thermoreactor 10 is connected via a Rohgaszweigleitung 20 with a Rohgaszuführleitung 22. An exhaust gas source 24, for example in the form of an exhaust gas collecting and exhaust mixing device feeds the raw gas supply line 22 with the exhaust gas (raw gas) to be cleaned.

The exhaust gas to be purified, which is supplied to the regenerators 14 of the thermoreactor 10 via the raw gas branch lines 20, usually contains liquid droplets. These drops of liquid originate, for example, from the upstream process 24. This state can also occur, for example, if the temperature difference between the upstream Process 24 and the raw gas inlet into the emission control system at the transfer point from the Rohgaszuführleitung 22 in the Rohgaszweigleitungen 20 condensation of the moisture contained in the raw gas result, which are delivered in the resulting gas stream at the outlet of Rohgaszweigleitungen 20 in the thermoreactor 10 as liquid drops.

Furthermore, the prechamber of each regenerator 14 of the thermoreactor 10 is connected via a respective clean gas branch line 26 to a clean gas line (first discharge line of the invention) 28. The cleaned in the thermoreactor 10 and cooled in the regenerator 14 gas (clean gas) is passed through the clean gas line 28 to an exhaust chimney 30 through which the clean gas is discharged to the environment.

The operation of such a thermoreactor is described, for example, in WO 2008/011965 AI in more detail. In this regard, reference is made in full to this document.

As shown in Fig. 1, the combustion chamber 12 of the thermoreactor 10 via hot gas branch lines 32 with a hot gas line (second discharge line of the invention) 34 is connected. Via this hot gas line 34, hot exhaust gas (hot gas) purified by thermal oxidation is conducted past the regenerator 14 or removed from the exhaust gas purification device before passing through a regenerator 14. In preferred embodiments, the hot gas is supplied via the hot gas line 34 to an energy recovery device.

This energy recovery device has a first heat exchanger 36 (another heat exchanger of the invention) and a second heat exchanger 38 (condensation heat exchanger of the invention) downstream of the first heat exchanger 36. Both heat exchangers 36, 38 are in heat exchange with a common heat exchange medium circuit 40a.

The first heat exchanger 36 serves as a steam generator or steam heater. In the first heat exchanger, the hot gas of, for example, about 1,000 ° C to, for example, about 400 ° C (first Temperature level) cooled. Depending on the design and / or efficiency of the first heat exchanger 36 and / or inlet temperature of the hot gas at the first heat exchanger 36, the first temperature level may also be below 400 ° C, for example at about 300 ° C, 200 ° C or even about 150 ° C. The enthalpy released during this cooling is used in the first heat exchanger 36 to heat up the heat exchange medium (here: water) of the circuit 40a to vaporization and overheating of the vapor.

The overheated by the first heat exchanger 36 steam is supplied in the circuit 40 a steam turbine 42. This steam turbine 42 is coupled to a generator 44 for generating electricity in order to generate electrical energy in a known manner. Downstream of the steam turbine 42, a cooling tower 43 is preferably provided for further cooling of the water.

In the second heat exchanger 38, the hot gas exiting from the first heat exchanger 36 is further cooled, for example to about 60 ° C (second temperature level). During this cooling process, the moist components of the hot gas condense.

If the first temperature stage is below about 230 ° C, in particular between 200 ° C and 100 ° C, preferably at about 150 ° C, the second heat exchanger 38 can be inexpensively made of carbon or plastic material. Such heat exchangers are known, for example, from WO 2009/007065 A1, the disclosure of which is to be included here.

In this case, the hot gas gives it its inherent enthalpy between inlet and outlet temperature in and out of the second heat exchanger 38, the enthalpy of enthalpy of the moisture contained in the hot gas by condensation, and the inherent enthalpy of the condensate between inlet and outlet temperature in or out of the second heat exchanger 38 free. The sum of these released enthalpies is released to the heat exchange medium of the circuit 40a to preheat the heat exchange medium. The exhaust gas purification device described above enables efficient energy recovery, in particular also in the event that the raw gas supplied via the raw gas branch lines 20 is supersaturated and contains moisture in the form of liquid droplets.

During the heating process in the thermoreactor these liquid droplets are vaporized. If the evaporation product in the thermoreactor releases no reaction energy, as is the case, for example, for water, which can pass through the thermoreactor as steam, the evaporation enthalpy used for the evaporation of the liquid is recovered in the condensation heat exchanger 38 by condensation and in this embodiment to a Heating medium delivered for further use.

The emerging from the second heat exchanger 38 hot gas is finally fed via a connecting line 46 of the clean gas line 28 to be ultimately discharged through the exhaust chimney 30 to the environment. The exhaust air flow in the exhaust chimney 30 is also relatively dry due to the condensation heat exchanger 38 used in the energy recovery device.

As indicated in FIG. 1, the condensate formed during cooling of the hot gas in the second heat exchanger 38 can optionally be returned to the process via a condensate removal 48. For example, the condensate can be supplied to the circuit 40a as a heat exchange medium.

Fig. 2 shows a system for purifying a methane-containing mine ventilation gas according to a second embodiment of the present invention. The same or analogous components are identified by the same reference numbers and a repetition of the corresponding descriptions is dispensed with.

The exhaust gas purification device illustrated in FIG. 2 is different from that of the first embodiment by the energy recovery device. As shown in Fig. 2, the first heat exchanger 36 (another heat exchanger of the invention) of the energy recovery device is in heat exchange with a first heat exchange medium circuit 40b. This first heat exchange medium circuit 40b contains, like the common heat exchange medium circuit 40a of the first embodiment, a power generation device comprising a steam turbine 42 and a generator 44 and a cooling tower 43.

The second heat exchanger 38 (condensation heat exchanger of the invention) of the energy recovery device is in heat exchange with a second heat exchange medium circuit 40c, which is configured as an open circuit and separately to the first heat exchange medium circuit 40b. The heat exchange medium of the second heat exchange medium circuit 40c is, for example, service water which is supplied to a hot water consumer or a heating medium which is supplied to a district heating connection. However, it can also be provided that the heat exchange medium of the second heat exchange medium circuit 40c is a thermal oil of an intermediate circuit for

Coupling of an RC, in particular an ORC system or directly a working medium of an RC, in particular an ORC system is. In the second case, the second heat exchanger 38 serves as a direct evaporator for a working medium, in particular an organic working medium for operating a system according Rankine cycle, preferably the Rankine turbine drives a generator. In this way, an efficiency of

Electricity generation of the entire system, comprising the steam turbine 42 and the Rankine turbine, be increased.

Fig. 3 shows a system for purifying a methane-containing mine ventilation gas according to a third embodiment of the present invention. Here are the same or

analog components are identified with the same reference numerals and a repetition of the corresponding descriptions is omitted.

The exhaust gas purification device illustrated in FIG. 3 is different from those of the first two embodiments by the energy recovery device. As shown in FIG. 3, the first heat exchanger 36 of the energy recovery device is in heat exchange with a first heat exchange medium circuit 40b. This first heat exchange medium circuit 40b includes, like the common heat exchange medium circuit 40a of the first embodiment and the first heat exchange medium circuit 40b of the second embodiment, a power generation device comprising a steam turbine 42 and a generator 44 and a cooling tower 43.

The second heat exchanger (condensation heat exchanger) 38 of the energy recovery device is in heat exchange with the raw gas stream delivered by the exhaust gas source 24, specifically methane-containing mine ventilation gases (VAM). In particular, the second heat exchanger 38 is arranged upstream of the thermoreactor 10 in the raw gas supply line 22. In the second heat exchanger 38, the hot gas exiting the first heat exchanger 36 is cooled, for example, from about 300 ° C to about 200 ° C.

4 shows a system for purifying a VOC-containing exhaust air of an exhaust gas source 24, for example a methane-containing mine ventilation gas or a solvent-containing process exhaust air, according to a fourth exemplary embodiment of the present invention. The same or analog components are identified by the same reference numerals and a repetition of the corresponding descriptions is omitted.

The exhaust gas purification device illustrated in FIG. 4 differs from the first exemplary embodiment according to FIG. 1 in that the cooler clean gas discharged via the clean gas line (eg about 70 ° C.) is mixed with the hot gas emerging from the first heat exchanger 36 of the energy recovery device (eg about 300 ° C) is mixed before this mixed clean gas (eg, about 180 ° C) downstream in the second heat exchanger

(Condensation heat exchanger) 38 enters as a heat source. In the second heat exchanger 38 then the mixed clean gas on the dew point of a vapor component, in particular Steam, cooled, so that the stored in both partial streams evaporation enthalpy can be transferred to the circulating in the common heat exchange medium circuit 40 d heat exchange medium. It can also be provided that the admixture or supply of the gas streams via a mixing and / or swirling device is supported. As a result, an advantageous mixing, in particular homogenization of the mixture of the differently tempered gas streams can be promoted. As an alternative to the embodiment shown in FIG. 4, analogously to the exemplary embodiment according to FIG. 2, the residual and / or enthalpy of vaporization of the gas mixture can also be transferred to a heat exchange medium circulating in the second heat exchange media circuit 40c.

The thus characterized variants are particularly suitable when the mixture formation between the hot gas of the first temperature stage and the cooler clean gas exit temperature from the thermoreactor 10, a mixture temperature of less than 250 ° C can be set, resulting in an advantageous and cost-effective implementation of the second heat exchanger according to the nature of WO 2009/007065 Al leads. 5 shows a system for purifying a VOC-containing exhaust air of an exhaust gas source 24, for example a methane-containing mine ventilation gas or a solvent-containing process exhaust air, according to a fifth exemplary embodiment of the present invention. The same or analog components are identified by the same reference numerals and a repetition of the corresponding descriptions is omitted.

The exhaust gas purification device illustrated in FIG. 5 differs from the second exemplary embodiment according to FIG. 2 in that a third heat exchanger 50 is provided in the clean gas line 28. In the third heat exchanger 50 (condensation heat exchanger of the invention) emerging from the thermoreactor 10 via the clean gas line 28 Pure gas further cooled, for example, to about 60 ° C (corresponding to the second temperature stage of the second heat exchanger 38). During this cooling process, the moist constituents of the pure gas condense, whereby a residual and / or enthalpy of vaporization of the pure gas can be transferred to a heat exchange medium.

In the variant of this exemplary embodiment shown in FIG. 5, the first heat exchanger 36 and the second heat exchanger 38 are in heat exchange with a common heat exchange medium circuit 40a (similar to the first exemplary embodiment of FIG. 1). In addition, the second heat exchanger 38 and the third heat exchanger 50 are cooperatively communicated through a common heat exchange medium circuit 40e, and the heat exchange medium is preheated in the third heat exchanger 50. As a result, all three heat exchangers 36, 38, 50 are in operative relationship via a common heat exchange medium circuit, whereby vapor formation for driving the steam turbine 42 can be advantageously maximized.

As an alternative to the variant shown in FIG. 5, provision may also be made for the third heat exchanger 50 to be in operative connection with the second heat exchanger 38 via a common second heat transfer medium circuit 40f and thus to supply the heat energy which can be supplied to a further heat user in a manner analogous to that shown in FIG 2 is increased.

Such an embodiment is shown in Fig. 6 as a sixth embodiment. The same or analog components are identified by the same reference numerals and a repetition of the corresponding descriptions is omitted. The second heat exchange medium circuit 40f is designed as a working medium circuit of a Rankine cycle. The working medium and thus the second heat exchange medium is preferably an organic working medium, which in particular at lower temperature levels has more favorable evaporation properties than the medium water of the steam turbine 42. The second heat exchanger 38 serves as an evaporator for the working medium, which subsequently via a Rankine turbine 54 is relaxed. The Rankine turbine 54 drives another generator 56. Alternatively, it can also be provided that the Rankine turbine 54 via a coupling or transmission system with the shaft of the

Generator 44 is in operative relationship, which could be dispensed with a second generator. The relaxed in the Rankine turbine 54 working fluid is further cooled by a capacitor 58 so that it condenses out again. Subsequently, it is supplied in predominantly liquid form to the third heat exchanger 50. The third heat exchanger 50 transmits the residual and / or enthalpy of vaporization of the clean gas of the thermal reactor 10 to the liquid working medium, as a result of which it is preheated and possibly even partially vaporized.

It can also be advantageous if the second and / or third heat exchanger 38, 50 is designed according to DE 10 2014 201 908 AI, in particular when integrating an RC / ORC system in the manner of a flow apparatus or a system of flow apparatuses. The disclosure of DE 10 2014 201 908 AI is hereby incorporated in full, in particular concerning the structure of the flow apparatus, the flow guide in the flow apparatus, a system of flow apparatus and the operating method for fluid guidance in

Referred to flow apparatus.

In known regenerative thermoreactors 10 without hot gas use via the second discharge line 34 and an energy recovery device in the sense of the embodiments of FIGS. 1 to 6 and WO 2008/011965 Al, it may also be useful and advantageous, a condensation heat exchanger 60 (for example, according to Art of the third heat exchanger 50 according to the example of FIG. 5) in the first discharge line 28, as illustrated in FIG. 7 as the seventh embodiment.

In this case, the clean gas flowing out in the clean gas line 28 cools in the condensation heat exchanger 60 below a dew point of a vapor component. As a result, the residual and / or enthalpy of vaporization, which has not been recovered in the regenerators 14 of the regenerative thermal reactor 10, can be transferred to a heat exchange medium of a corresponding heat exchange medium circuit 40g. So, for example 3, the incoming raw gas are preheated analogously to the embodiment according to FIG. Alternatively, another heat user, for example a hot or hot water supply or an ORC system, can be supplied with thermal energy. 8 shows an eighth embodiment of an exhaust gas purification device according to the invention, a further modification of the embodiment of Fig. 1. In this case, the same or analogous components are denoted by the same reference numerals and a repetition of the corresponding descriptions is omitted. The exhaust gas purification device illustrated in FIG. 8 is different from that of the first embodiment by the energy recovery device.

The first heat exchanger 36 and the second heat exchanger 38 are in heat exchange with a common heat exchange medium circuit 40h. In this case, the heat exchange medium downstream of the steam turbine 42 is fed to a further condensation heat exchanger 64, which is arranged upstream of the thermoreactor 10 in the raw gas supply line 22. The heat exchange medium cooled in this further condensation heat exchanger 64 to, for example, approximately 60 ° C. is then fed back to the condensation heat exchanger 38 upstream of the first heat exchanger 36.

REFERENCE NUMBER LIST

10 thermoreactor

12 combustion chamber

14 regenerators

16 burners

18 gas supply

20 raw gas branch line

22 raw gas supply line 24 exhaust source

26 clean gas branch line

28 first discharge line, clean gas line

30 exhaust chimney

32 hot gas branch line

34 second discharge line, hot gas line

36 first heat exchanger, another heat exchanger

38 second heat exchanger, condensation heat exchanger

40a-h heat exchange media circuits

42 steam turbine

43 cooling tower

44 generator

46 connection line

48 Condensate drainage

50 third heat exchanger, condensation heat exchanger

52 condensate drainage

54 Rankine turbine

56 generator

58 capacitor

60 fourth heat exchanger, further condensation heat exchanger

62 condensate drainage

64 fifth heat exchanger, condensation heat exchanger

Claims

Device for thermal exhaust gas purification, comprising:

a thermoreactor (10) to which a raw gas to be purified can be supplied and in which the raw gas supplied is thermally cleanable; and

an energy recovery device, to which a gas purified in the thermoreactor (10) can be supplied via at least one discharge line (28, 34),

wherein the energy recovery device comprises at least one condensation heat exchanger (38, 50, 60, 64) in which the purified gas is cooled so that condense substances contained in the purified gas condense, and thereby released enthalpies to a heat exchange medium and / or the Raw gas upstream of the thermoreactor (10) are deliverable.

Apparatus according to claim 1, wherein

the thermoreactor (10) has a combustion chamber (12) in which the raw gas supplied is thermally cleanable;

the energy recovery device is connected to the combustion chamber (12) of the thermal reactor (10) via the discharge line (34) for supplying to the energy recovery device a purified gas produced during the thermal cleaning process in the combustion chamber (12); and

the energy recovery device comprises:

a further heat exchanger (36), in which the cleaned gas can be cooled to a first temperature level and an enthalpy which is thereby released can be delivered to a heat exchange medium; and

the condensation heat exchanger (38, 50, 64), which is arranged downstream of the further heat exchanger (36) and in which the purified gas is further cooled to a second temperature level lower than the first temperature stage, so that condensables contained in the purified gas condense, and released enthalpies to a heat exchange medium and / or the raw gas upstream of the thermoreactor (10) can be dispensed.

Apparatus according to claim 2, wherein the further heat exchanger (36) and the condensation heat exchanger (38) are in heat exchange with a common heat exchange medium circuit (40a, 40d, 40h), wherein the condensation heat exchanger (38) in the common heat exchange media -Circulation (40a, 40d, 40h) upstream of the further heat exchanger (36) is arranged.

Apparatus according to claim 2, wherein the further heat exchanger (36) is in heat exchange with a first heat exchange medium circuit (40b) and the condensation heat exchanger (38) with a second, separate from the first heat exchange medium circuit (40b) heat exchange media circuit (40c, 40f) is in heat exchange.

Apparatus according to claim 2, wherein the further heat exchanger (36) is in heat exchange with a first heat exchange medium circuit (40b) and the condensation heat exchanger (38) is in heat exchange with a raw gas supply line (22) upstream of the thermoreactor (10).

Apparatus according to claim 2 or 3, wherein in the common heat exchange medium circuit (40h) downstream of the further heat exchanger (36), a further condensation heat exchanger (64) is provided with a Rohgaszuführleitung (22) upstream of the thermoreactor (10) in Heat exchange stands.

Device according to one of claims 3 to 6, wherein in the common heat exchange medium circuit (40a, 40d) or the first heat exchange medium circuit (40b) downstream of the further heat exchanger (36), a power generating means (42, 44) is arranged. Apparatus according to claim 4 or 7, wherein in the second heat exchange medium circuit (40c, 40f) downstream of the condensation heat exchanger (38) at least one hot water consumer and / or a district heating connection and / or an RC or ORC system (54-58 ) are arranged.

Apparatus according to any one of the preceding claims, wherein a condensate generated in the condensation heat exchanger (38, 50, 60) is communicated via a condensate

Condensate discharge (48, 52, 62) is traceable back to the process.

Device according to one of the preceding claims, in which the thermal reactor (10) is a thermal oxidation reactor, preferably a regenerative thermal oxidation reactor.

Method for thermal exhaust gas purification, with the steps:

thermal cleaning of a raw gas to be purified in a thermoreactor (10); and

Cooling a purified gas produced during the thermal cleaning process in the thermoreactor (10) in a condensation heat exchanger (38, 50, 60, 64) in such a way that condensable substances contained in the purified gas condense, thereby releasing enthalpies to a heat exchange medium and / or the raw gas is discharged upstream of the thermoreactor (10).

The method of claim 11, wherein

the thermal cleaning of the raw gas takes place in a combustion chamber (12) of the thermoreactor (10);

the cleaned gas resulting from the thermal cleaning process in the combustion chamber (12) is cooled in a further heat exchanger (36) to a first temperature stage, an enthalpy thus released being delivered to a heat exchange medium; and the purified gas in the condensation heat exchanger (38) downstream of the further heat exchanger (36) to a second temperature level lower than the first

Temperature stage is further cooled so that condensable substances contained in the purified gas condense, and released enthalpies are delivered to a heat exchange medium and / or the raw gas upstream of the thermoreactor (10).

13. The method of claim 12, wherein the further heat exchanger (36) and the condensation heat exchanger (38) are in heat exchange with a common heat exchange medium circuit (40a, 40d, 40h) and the heat exchange medium of the common heat exchange medium circuit (40a, 40d, 40h) in the

Condensation heat exchanger (38) is preheated.

14. The method of claim 12, wherein the further heat exchanger (36) is in heat exchange with a first heat exchange medium circuit (40b) and the condensation heat exchanger (38) with a second, from the first heat exchange medium circuit (40b) separate heat exchange media Cycle (40c, 40f) is in heat exchange.

15. The method of claim 12, wherein the further heat exchanger (36) with a first heat exchange medium circuit (40b) in heat exchange and the condensation heat exchanger (38) with a Rohgaszuführleitung (22) upstream of the thermoreactor (10) is in heat exchange ,

16. The method of claim 12 or 13, wherein in the common heat exchange medium circuit (40h) downstream of the further heat exchanger (36), a further condensation heat exchanger (64) is provided with a Rohgaszuführleitung (22) upstream of the thermoreactor (10 ) is in heat exchange.

17. The method according to any one of claims 12 to 16, wherein in the further heat exchanger (36) heated heat exchange medium is used to generate electricity.

18. The method of claim 14 or 17, wherein the heat exchange medium of the second heat exchange medium circuit (40c, 40f) is a service water or a heating medium.

19. The method according to any one of claims 11 to 18, wherein a in the

Condensation heat exchanger (38, 50, 60) condensate generated via a

Condensate discharge (48, 52, 62) is returned to the process.

20. Use of the device according to one of claims 1 to 10 or the method according to one of claims 11 to 19 for cleaning a mine exhaust gas, in particular a methane-containing mine ventilation gas, or a combustible constituents containing, in particular VOC-containing exhaust air.

21. Use of the device according to one of claims 1 to 10 or the method according to one of claims 11 to 19 for cleaning a liquid droplet-containing raw gas.