WO2022122113A1

WO2022122113A1 - Rotary catalytic converter, method for operation thereof, apparatus and method for converting chemical energy into electrical energy, and use of a rotary catalytic converter

Info

Publication number: WO2022122113A1
Application number: PCT/EP2020/084859
Authority: WO
Inventors: Udo Hellwig
Original assignee: Erk Eckrohrkessel Gmbh
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2022-06-16
Also published as: EP4255613A1

Abstract

The present invention relates to a rotary catalytic converter, a method for operating the rotary catalytic converter, an apparatus and a method for converting chemical energy into electrical energy, and the use of the rotary catalytic converter according to the invention. The rotary catalytic converter (6) comprises a rotary body (10) for the inflow of a fluid (29) and for the transfer of kinetic energy of the inflowing fluid (29) to the rotary body (10), wherein the rotary body (10) is designed to have at least one surface region for carrying out catalysis, in particular for carrying out heterogeneous catalysis, of at least one constituent of the inflowing fluid (29).

Description

ROTARY CATALYST, METHOD OF OPERATION, EQUIPMENT AND METHOD FOR CONVERTING CHEMICAL ENERGY TO ELECTRICAL ENERGY AND USE OF A ROTARY CATALYST

The present invention relates to a rotary catalyst, a method for operating the rotary catalyst, a device and a method for converting chemical energy into electrical energy, and a use of the rotary catalyst according to the invention.

In order to protect the environment, engine exhaust gases must contain far fewer so-called nitrogen oxides than was previously permitted. In the case of combined heat and power plants with the usual electrical outputs in the range from 100 kW, the limit value is 60 ppm (parts per million), whereby volume fractions are designated and the volume fractions are related to 0°C. In the future, the limit of 30 ppm must not be exceeded, at least in some jurisdictions. Some approval authorities require a drop below 50% in practical operation to ensure that the limit value is never exceeded in the event of load changes.

It is state of the art that gas turbines, which at least partially absorb the kinetic energy of the exhaust gas flow, are connected behind internal combustion engines. These gas turbines are usually coupled to generators to convert kinetic energy into electrical energy.

Gas turbines are performance-limited by the material of the rotor's load-bearing elements. This can be compensated for by internal cooling of these elements by passing the cooling medium and letting it flow with the working medium, or by a conservative cooling process in which the cooling medium is preserved.

The former is state of the art, with steam or air being used as cooling media. The latter is also prior art, but with the restriction that the cooling medium, preferably water, is supplied to the blades via the rotor shaft and evaporates in the blades.

Furthermore, it is state of the art that denitrification takes place catalytically on ceramic contacts, ie by heterogeneous catalysis (SCR). The ceramic contacts are housed in voluminous cylindrical containers in the form of a fixed bed. Of the Mass transfer in such beds is generally sluggish, since transport is inhibited within the pore space of the ceramic.

The ceramic can be bead beds, honeycomb bodies or the like. In all ceramic bodies, the actual reaction takes place in the pore space. The transport of the educts into this space and the transport away from this space takes place by diffusion. To ensure that the diffusive transport does not take too much time, the reactive ceramic mass is chosen to be sufficiently large. The key parameter for the design of the layer is the so-called space-time, namely the ratio of the volume flow of the flue gas to the catalyst volume.

However, the necessarily large catalyst volumes selected lead to the disadvantage that a considerable pressure drop has to be applied to transport the flue gas. This means that the mechanical energy that was available upstream of the exhaust gas stream for power generation in the gas turbine in relation to the catalyst is now consumed for transport through the catalyst bed or the ceramic honeycomb.

In addition, the catalysis does not usually take place isothermally, with the result that only part of the bed is available with sufficient reactivity.

In the event that the catalyst also responds to non-oxidized fuel such as carbon monoxide and soot, the reaction may "runaway", with the risk of local overheating and/or damage to the catalyst material.

The invention is therefore based on the object of providing a rotary catalytic converter, a method for operating the rotary catalytic converter, a device and a method for converting chemical energy into electrical energy and a use of the rotary catalytic converter according to the invention, with which flue gas treatment can be carried out in a simple and energy-efficient manner can be done.

This object is achieved by the rotary catalyst according to claim 1, by a method for operating the rotary catalyst according to claim 11, by a device for converting chemical energy into electrical energy according to claim 13 and a method for converting chemical energy into electrical energy according to claim 14 and a use of the rotary catalyst according to the invention according to claim 15 dissolved A first aspect of the present invention is a rotary catalytic converter, comprising a rotary body for the inflow of a fluid and for the transfer of kinetic energy of the inflowing fluid to the rotary body, the rotary body having at least one surface area for implementing catalysis, in particular for implementing heterogeneous catalysis, at least a component of the inflowing fluid is set up.

The rotary catalytic converter according to the invention thus fulfills a dual function, namely on the one hand the absorption of kinetic energy of the inflowing fluid with the possibility of converting this energy at least partially into electrical energy when the rotary catalytic converter is coupled to a generator, and on the other hand the simultaneous catalytic reaction with the aim of Denitrification of components of the inflowing fluid.

The rotary catalytic converter enables this double function with a very small installation space requirement. In addition, the rotary catalytic converter is highly efficient both for absorbing kinetic energy and for denitrification.

Ultimately, the rotary catalytic converter ensures that, despite the catalytic reaction being implemented, a large proportion of the kinetic energy of the inflowing fluid can still be used or converted into electrical energy.

In particular, it is provided that the surface of the rotary body is formed at least partially by a catalytically active material which is able to bring about reduction reactions for the decomposition of nitrogen oxides in the inflowing fluid.

The specificity of the catalytically active material should be such that at least nitrogen monoxide is broken down quantitatively.

The rotary body can have at least one disk arranged on an axis of rotation for converting the enthalpy of a gas volume flow as the inflowing fluid into mechanical energy of the rotary body, which can be set in rotation with the gas volume flow when the flow is essentially tangential, so that mechanical energy is transferred to a disk coupled to the disk Driven element, in particular a shaft, is removable, and the rotary catalytic converter has at least one gas receiving space for receiving and discharging the gas volume flow flowing at least partially tangentially onto the disc.

In an advantageous embodiment, the rotating system or the rotating body comprises a disk regime in which the individual disks are arranged orthogonally on a Shaft are applied, resulting in the rotor of a disk turbine based on the "Tesla" system.

In other words, the rotating body is a disc rotor turbine with at least one, preferably several discs arranged on an axis of rotation, which can be set in rotation with a gas volume flow when the flow is essentially tangential, so that mechanical energy is applied to a disc or discs connected to the disc or discs. shaft coupled to the disks is detachable.

A tangential flow is understood to mean a flow towards the disk or disks in a radially outer area of the disk or disks in a direction of flow that is essentially perpendicular to a plane in which the axis of rotation runs. The peripheral surface of the disk or disks is preferably flowed tangentially.

The disc is or the discs are arranged on an axis of rotation. The tangential flow causes the disk or disks to rotate, in other words into a rotational movement about the axis of rotation. Furthermore, the disk or disks is/are coupled to a shaft, by means of which the mechanical energy of the rotation can be taken off. In one embodiment, the disk or disks is/are arranged on the shaft in a rotationally fixed manner.

The disk has or the disks essentially have a round shape in at least one plane, in particular in only one plane, to which the axis of rotation of the disk or disks is perpendicular. However, it is also possible to deviate from this round shape, for example in such a way that the disk or disks has or have the shape of a shovel. In other words, instead of disks, blade elements can also be used, such as are known from a radial turbine, for example.

The gas that flows against the disk or disks is also referred to as the working medium. This can be, for example, a flue gas from an incineration plant or, alternatively, a working medium that is heated by means of a heat exchanger device. In the latter case, the working medium is advantageously an inert gas, in particular xenon. Noble gases are useful because they have a low specific heat capacity and are therefore able to reduce high temperature differences and corresponding pressures in one expansion step.

The rotary catalytic converter has a gas receiving space. The gas, which flows tangentially against the disk or disks, is introduced into the gas receiving space through an inlet device, received therein and through an outlet device deployed. In other words, the gas receiving space is set up so that the gas can flow into and out of it, so it consequently has an inlet and an outlet, with the inlet preferably being in an area remote from the axis of rotation of the disk or disks and the outlet in is arranged in an area close to the axis. The disk or disks, preferably all disks, of the rotary catalytic converter are arranged within the gas receiving space.

The distance between the discs should be dimensioned in such a way that the educts located in the middle of the gap reach the reactive surface of the discs before the end of the residence time of the exhaust gas in the gap volumes. In this way it is possible that almost all reactive components of the flue gas can leave the reaction space. The mass transfer in a disk system chosen according to the Tesla principle is favored by a significant increase in the radial relative velocity.

In a further advantageous embodiment, it is provided that a disk body forming the disk has at least one cavity in which a cooling medium, in particular a cooling liquid, was or can be accommodated for the purpose of cooling the disk body.

A disk is formed by a disk body. A disk body of a disk, in particular of each disk, has at least one cavity. It cannot be ruled out that a pane has several cavities. In particular, the cavity extends from a radially inner region of the disk into a radially outer region of the disk.

Thus, in this embodiment of the rotary catalytic converter, it is provided that the disk or disks in the disk body forming a respective disk have at least one cavity in which a cooling liquid is or can be received for the purpose of cooling the disk body.

In particular, the cooling medium is a cooling liquid, which means that the cooling medium is in the liquid phase at ambient conditions. For example, the cooling medium is water. Organic or inorganic fluids and metals can be used as cooling media.

A respective disk can be set up to at least partially evaporate cooling medium contained in its cavity when heat is supplied to the disk in the cavity from the gas volume flow flowing against the disk.

In other words, the disk is designed to extract heat from the

Gas volume flow, which flows against the pane or panes or flows around them, absorb and deliver to the cooling medium in the cavity of the disk or disks, so that the cooling medium evaporates at least partially inside the disk body or the disk body.

If there are several disks, at least one of the disks is set up to evaporate coolant contained in its cavity when heat is supplied from the gas volume flow flowing around it in the cavity. In principle, it is also possible that at least one of the discs is set up to heat coolant contained in its cavity in the cavity when heat is supplied from the gas volume flow flowing around it, essentially without evaporation.

In one embodiment, the vapor of the cooling medium is fed back to the shaft, in particular the shaft of the rotor, and is preferably expanded to dissipate the force, condensed and fed back into the disk or disks. In this case, the cooling medium is led out of the cavity for the purpose of condensation and returned to the cavity after condensation.

However, the cooling medium condensed in this way can also be used in another way, in that, according to another embodiment, it does not leave the force-absorbing elements of the rotor, ie the disk or disks, but rather is evaporated and condensed in situ. This process is similar to that in so-called “heat pipes”. The easiest way to do this is with rotating discs of a rotary catalytic converter designed as a disc turbine based on a Tesla turbine, the necessary condition being that the discs are hollow, in other words have a cavity, and contain a cooling medium. As the discs rotate, the cooling medium is pushed radially outwards to the outer edge of the disc, where it is vaporized by hot gas in the vicinity of the disc. The vapor of the cooling medium has a significantly lower density than the liquid phase of the cooling medium, so that it can always be displaced by the liquid phase. This accommodates the fact that the heat flow densities at the radially outer edge of the disk are particularly high, but the liquid phase is able to absorb high heat flow densities without forming a vapor cushion.

For reasons of continuity, the vapor is guided into the central region of the disk or disks, i.e. radially inwards, where it condenses, since the gas, which can be flue gas for example, is colder near the axis of rotation or the shaft. The heat flows are advantageously set or adjustable via the boiling temperature, the amount of liquid and the gas temperatures in such a way that the heat flow that is absorbed is equal to the heat flow that is given off. Due to the heat dissipation in the outer pane area, the gas is unable or only to a very limited extent to work on the pane. This means that heat transfer predominantly takes place in this area the cooling medium takes place inside the disc body. In the central, i.e. radially inner disk area, the heat is given off again to the gas, which, however, is associated with an equivalent work performance. That is, the gas transfers force to the disk almost isothermally.

The disk or disks of the disk rotor turbine according to the invention is or are designed in such a way that it has or have an internal fluid circuit or cooling medium circuit in the cavity, so that evaporation occurs in the outer area and condensation occurs in the central, i.e. radially inner area Consequence of external heat supply and heat dissipation to a surrounding gas, preferably a hot flue gas, which is used as a working medium to generate mechanical energy.

The disk body typically, but not necessarily, consists essentially of a metal. The strength of metals depends in principle on the temperature and progressively decreases with increasing working temperature, in particular with increasing temperature of the gas volume flow of the body of revolution. This means that by cooling the disks according to the invention, the rotary catalytic converter can be operated at a higher working temperature and the work consumption can be increased. With cooled disks, it is therefore possible to use light materials with low strength for the design of the disk body, without there being any risk of breakage. At the same time, this allows a significantly more compact design to be implemented.

The effect of the cooling is that a respective disk is exposed to a relatively low thermal load, so that a variety of materials can be used to form the respective disk body, including materials that have a low density and therefore a low weight. In particular, disks made of materials with a very low density can be rotated at a very high speed due to the resulting low mass moment of inertia, so that the turbine can be operated at a high speed and consequently with high efficiency.

In a specific embodiment, the rotary catalytic converter comprises a plurality of discs which are arranged on an axis of rotation, the disc bodies of mutually adjacent discs being mechanically connected to one another by means of connecting elements. For this purpose, the disk bodies can, for example, comprise at least one recess or sleeve, which is designed for the mechanical connection of at least one adjacent disk. In other words, the disk bodies are combined with one another by sleeves that enable external attachment. Advantageously, spacer elements are arranged between two adjacent panes to ensure a defined distance. The spacer elements are arranged mechanically, preferably in the radially outer area of the disks. A disk package is realized in this way.

In particular, to convert the enthalpy of a gas volume flow as the inflowing fluid into mechanical energy of the rotation body, the rotation body can have a plurality of disks arranged on a rotation axis, which can be set in rotation when the gas volume flow is approaching essentially tangentially, so that mechanical energy is transferred to an output element coupled to the disks , in particular a shaft, is removable, wherein a cooling medium, in particular a cooling liquid, is accommodated or can be accommodated in cavities in the discs for the purpose of cooling the disc body, and the cavities of the discs are fluidically connected to one another.

In this way, heating or cooling medium can flow through the panes.

In an alternative embodiment, it is provided that the rotary body has a plurality of discs arranged on an axis of rotation for converting the enthalpy of a gas volume flow as the inflowing fluid into mechanical energy of the rotary body, which can be set in rotation with the gas volume flow when the flow is essentially tangential, so that mechanical energy is a driven element coupled to the disks, in particular a shaft, wherein a cooling medium, in particular a cooling liquid, is or can be accommodated in cavities of the disks which are separated from one another in terms of flow in order to cool the disk body.

This means that the discs are hollow bodies equipped with a fluid that remains in the cavity.

The cavity in each pane is dimensioned in such a way that evaporation takes place in the area where heat is supplied and condensation takes place in the area where heat is dissipated. The heat is supplied in the radially outer pane area and the condensation in the area close to the shaft, i.e. radially inner area. The preserved compensating fluid ensures that the wall temperatures in the pane are almost isothermal, since evaporation and condensation take place at almost the same, theoretically even the same temperature. Along the radial direction there is a thermally neutral zone between the evaporation and condensation area, in which almost no heat transfer takes place, since the flue gas temperature and the wall temperature have equalized. In order to realize the catalytic effect, the rotary body can have a coating with noble metal or an alloy based thereon, at least in certain areas. Furthermore, an iron oxide can also be used here.

Platinum, gold and silver are particularly suitable as noble metals, whereby the reactivity of the catalyst should be so high that the actual reaction time is negligible compared to the time for the transverse transport of the starting materials and products, in the sense of a mass transport inhibition.

In a special embodiment it is provided that the body of revolution is formed at least in sections from graphene.

In particular, the body of revolution can be made entirely of graphene.

The graphene can be at least partially present in mechanically and/or chemically interconnected fibers such that the fibers present in an ordered or disordered form form a disk.

Graphene is a carbon compound that has a two-dimensional structure.

The carbon atoms are arranged in a honeycomb pattern in the plane. The chemical structure of graphene results in a tensile strength more than 100 times that of steel at a density of less than 0.2 kg/m ³ . In addition, graphene has a thermal conductivity of more than 4000 W/(m K).

With regard to the rotating body, the use of graphene allows significantly lower moments of inertia and centrifugal forces to be achieved compared to other materials.

In particular, it is provided that the body of revolution comprises a knitted fabric of graphene threads or fibers.

Fibers can also be formed in a disordered arrangement to form a fleece, felt or tangle, and in an ordered arrangement to form a woven, knitted, knitted fabric, netting or stitch-bonded fabric, from which the rotating body is at least partially formed. In this case, it is not impossible to combine several of the fiber arrangements mentioned and/or to construct the rotary body from layers of the same or different fiber arrangements.

The individual fibers should preferably have a diameter of less than 5 nm, particularly preferably less than 0.1 nm. Carbon fibers, which are based on graphene as a starting material, are a deformation of the two-dimensional graphene in its basic form, which is bent or folded. The advantage of small diameters is that a laminar flow occurs at the fibers or that there is essentially no detachment of the streamlines when the flow flows around the fibers. In other words, creeping flow conditions are set. A typical Reynolds number characterizing the flow is, for example, less than 0.1, the Reynolds number being the product of the average velocity of the fluid, the fiber diameter and the reciprocal value of the kinematic viscosity of the gaseous fluid. A Reynolds number of 0.1 is calculated under the following conditions, for example:

Density graphene body 10 kg/m ³

Strength graphene body 1000 MPa

Max. outer peripheral speed 10000 m/s

Diameter fiber/filament 1 nm

Kinematic viscosity fluid 0.0001 m ² /s

In addition, in a further embodiment, the fibers form a body in an ordered or unordered manner, in particular on the radial outside of the essentially rotationally symmetrical body of revolution.

The fibers are mechanically and/or chemically bonded to one another. It is not excluded that the connection of the fibers takes place with the mediation of additives, which either remain in the body formed by the fibers or are removed again.

Graphene can e.g. B. be used in the form of aerographs.

This design of the disks of the rotary catalytic converter made of graphene leads to a correspondingly low weight of the rotary body. A low weight goes hand in hand with a low mass moment of inertia and low centrifugal forces during the rotational movement of the rotating body, as a result of which very high rotational speeds and peripheral speeds can be achieved. Accordingly, it is possible to realize a rotary catalytic converter according to the invention with very small dimensions with conventional mechanical performance or with conventional dimensions and exceptionally high mechanical performance. The mechanical load on the components of the rotary catalytic converter can be significantly reduced in comparison, which has a positive effect on the operating costs. In addition, the low mass moment of inertia has an advantageous effect on flexible control of the speed during operation, since the rotary catalytic converter reacts more quickly to changes in the operating parameters than conventional turbines made of metal materials, for example. This is advantageous, for example, when starting up the rotary catalytic converter. A further advantage of making the body of revolution completely from graphene is, in addition to the lowest possible weight of the body of revolution, a reduced number of connection points and connection elements and thus a reduced number of potential mechanical weak points.

It is advantageous if the area of the body of revolution made of graphene is made in such a way that the graphene is distributed regularly and/or homogeneously over the circumference in the respective radius. In other words, this means that the difference in density, and thus the difference in mass, essentially does not vary over the circumference of the rotating body, or only varies at regular intervals.

In a further embodiment of the disk rotor turbine, the base body is formed in a radial outer area from the material of low density, in particular graphene, which is arranged on the radial outside of a support element of the disk rotor turbine, with the maximum radial extension of the support element r _t to the radius of the entire base body r _g is in a ratio of r _t /r _g = 0.2 to 0.5.

In other words, the base body in this embodiment is designed in such a way that, viewed radially from the inside outwards, first a hub is arranged as part of a carrier element and then a body made of the low-density material is arranged, with the carrier element and the hub forming a structural unit can be executed. It is advantageous if the carrier element, in other words the middle ring of the base body, encompasses at least 20%, but at most 50% of the total radius of the base body.

Advantageously, the carrier element is also designed to be rotationally symmetrical, in particular as a cylinder or hollow cylinder.

A further alternative configuration is a radially alternating arrangement of the low-density material with a further, different material, in particular a light metal such as aluminum or an aluminum alloy, in the form of a layered structure.

In a further embodiment, the carrier element is formed in an innermost area by a hub, and in its radially adjoining central area by a number of webs arranged axially next to one another, in particular in the form of disks, and with the webs in a radially outer area the low-density material is mechanical is firmly connected.

In this case, between the webs and the low-density material, another

Rotating body, in particular a hollow cylinder can be arranged with both the webs and the low-density material is mechanically firmly connected and serves to fix the webs in relation to the low-density material.

In a special embodiment of the rotary body, the central area of the rotary body is designed in such a way that webs are arranged in at least one, but preferably several planes perpendicular to the axis in an area between the hub and the low-density material. At least two radially extending webs are arranged in one plane. In principle, any number of webs is possible, with these advantageously being distributed at regular intervals over the circumference of the rotating body or the carrier element. The arrangement of the webs in a second parallel plane to the respective first adjacent plane can be offset in the direction of rotation with respect to this plane. It cannot be ruled out that the number of webs varies per level, it being advantageous if the number of webs continuously increases or decreases from the two outermost levels towards the middle of all parallel levels. The advantage of this configuration of the radially central area of the carrier element is a reduction in weight.

Webs designed in the form of disks can be designed as flat solid cylinders which are arranged parallel to one another. It is possible for the disks to have recesses for further weight reduction, with the recesses advantageously being distributed regularly over the circumference of the respective radius. Said recesses can be round or oval holes, for example.

A combination of discs and bars is also possible.

The number, dimensions and spacing of the respective bars or discs are dependent on the speed, the material properties of the bars or discs and the material properties of the rotating body.

In its radially outer region, the carrier element comprises a carrier body for mechanically fixing a body made of graphene. This means that the carrier body is set up on its radial outside to attach a body made of graphene to or on it. It is not excluded that the graphene is permanently connected to the carrier body, that is, represents a structural unit. It is conceivable, for example, that the graphene is permanently applied to the carrier body, e.g. B. by printing, and this support body is then mechanically connected to the central portion of the support member. On its radially inner side, the carrier body is connected to the webs and/or disks of the carrier element. In a further advantageous embodiment, the rotary catalytic converter has at least one flow guide device in its radially inner region for axially discharging the inflowing fluid.

The fact that the flow guide devices are arranged in a radially inner area means that they lie on a radius n to the axis of rotation, where n/r _g <0.3.

The gaseous fluid, which flows tangentially against the rotating body, is discharged inwards in a spiral shape on the axially aligned surface of the rotating body towards the center or towards the axis of rotation of the rotating body. During the spiral diversion, the fluid continues to give off energy and heat to the body of revolution. The flow guide device in the inner area of the rotary catalytic converter serves to divert the flowing fluid from the rotary catalytic converter. This can be made possible, for example, via recesses on the rotary body, in particular on a hub, which allow the fluid to flow out in the center parallel to the axis. A further possibility consists in providing at least one flow guide device wholly or partially on the shaft, provided that the rotary catalytic converter is connected to such a device, so that the fluid can be discharged via the shaft itself.

The flowing fluid leaves the rotary catalytic converter with less energy and less heat than when it entered it. It can be assumed that approximately 70% of the internal energy of the flowing fluid can be converted into mechanical energy by means of the rotary catalyst.

In the embodiment with graphs, it is provided in a further embodiment of the invention that the rotary catalytic converter comprises a housing, the housing comprising at least one inflow region for realizing a tangential flow onto the rotating body. To realize a tangential flow, the inflow area is adjoined by a flow line area, the cross section of which decreases with increasing distance along the flow lines of the fluid in the direction of flow from the inflow area.

In other words, the flow onto the rotary body by means of the inflow area initially takes place in a direction perpendicular to the orientation of the axis of rotation and is directed towards the outer edge of the rotary body. A flow guide area is connected to the inflow area. This is designed in such a way that the flow of the fluid is guided along the rotating body. This means that the flow guide area has a shape adapted to the round shape of the rotating body. In this case, the flow guide area preferably tapers continuously. The flow is consequently compressed along its path along the rotating body of revolution. this will realized, for example, in that the inner wall of a housing surrounding the body of rotation is continuously approximated in sections spirally to the body of rotation. The configuration leads to a more effective utilization of the energy of the flowing fluid. Fluid flowing tangentially onto the rotating body is thus guided through the flow line area on the outside of the rotating body, whereby it is caused by the fluid pressure and the reduction in the space available between the rotating body and an inner wall of the housing with an increase in the distance from the inflow area to the radial outside of the body of rotation is displaced and flows axially to the side of the body of rotation at this in the radial direction inwards.

It is possible to provide several inflow areas with an adjoining flow guide area for charging the rotary body with flowing fluid, with these preferably being arranged in such a way that they are evenly distributed over the circumference of the rotary body. A rotary catalytic converter preferably has two radially opposite inflow areas. In an embodiment with a plurality of bodies of rotation, each body of rotation should be subjected to fluid by means of one or more inflow areas of its own.

Furthermore, one embodiment of the rotary catalytic converter consists in that the material of at least one component of the housing radially surrounding the rotary body is at least partially a low-density material, in particular graphene.

The housing is preferably made entirely of graphene in the area surrounding the rotary body, as a result of which the housing and thus the rotary catalytic converter as a whole are given high strength with low weight.

When operating a rotary catalyst according to the invention with graphene, it is preferable to use a flowing gaseous fluid which has a proportion of oxidative components, in particular oxygen, of less than 5% by volume. Inert gases or inert gas mixtures are particularly preferred to be used as the inflowing fluid for the operation of the rotary catalytic converter.

In particular, when operating the rotary catalyst with graphene, there can be a ratio of the diameter D of the rotary body to the process pressure p of D/p<2.5-10 ³ , in particular of D/p<1.3-10 ³ , the pressure p being in bar and the diameter D are to be measured in meters. This means that at a pressure p of, for example, p=300 bar, which is conventional for turbines, a diameter of the rotating body D=0.4 m is sufficient to enable highly efficient operation, and at the same time with only one turbine stage or to convert essentially the present internal energy of the inflowing fluid into mechanical energy with only one rotary body.

The outer diameter of the rotating body results from the flow conditions such that the speed of the flowing fluid in the radial direction in the radially inner area of the rotating body, in particular in the area of the flow guide device, is approximately equal to the peripheral speed in this radial area. The ratio of the outer diameter of the rotating body to the diameter of the shaft is preferably 5 to 1.

The peripheral speed of the rotating body on its radial outside can be approximately determined from the square root of the quotient of material strength and material density. The peripheral speed at the shaft is obtained by multiplying it by the ratio of the shaft diameter to the diameter of the rotating body.

A further alternative embodiment of the rotary body provides that the rotary body is made of zeolite at least in a partial area of its outer surface.

The zeolite fulfills the catalyst function here. In particular, a body of revolution comprising zeolite can have a stainless steel coating.

In an alternative embodiment, a silica gel or another porous ceramic can also be used instead of zeolite.

In an alternative embodiment, it is provided that the rotary body is formed at least in regions from a tangle, knitted fabric, woven fabric, knitted fabric, mesh or stitched fabric made of stainless steel threads.

These textile forms can also be made of steel, copper or alloys based on them.

A further aspect of the present invention is a method for operating the rotary catalyst according to the invention, in which the rotary body of the rotary catalyst is flown with a fluid and thereby kinetic energy of the inflowing fluid is transferred to the rotary body, with at least part of the time at the same time the rotary body having at least one surface area Catalysis, in particular heterogeneous catalysis, carries out at least one component of the inflowing fluid.

Insofar as the rotary catalytic converter is designed as a disc rotor turbine for converting the enthalpy of a gas volume flow into mechanical energy, the method is such designed such that a gas volume flow is supplied essentially tangentially to the disk, flowing against it, so that the disk is caused to rotate due to friction.

The catalytic denitrification can be carried out in such a way that the unburned hydrocarbons (CH) and carbon monoxide (CO) serve as reducing agents, e.g.:

(cat)

This is made easier by the possibility of working isothermally, since the required reaction conditions can be adjusted in a targeted manner. In an advantageous embodiment of the method, it is provided that the reductively acting materials are available in a specific stoichiometric amount and the temperature is set with regard to the greatest conversion effect according to the Arrhenius function.

In an advantageous embodiment of the method for operating the rotary catalytic converter, it is provided that the inflowing fluid is a gas volume flow and heat of the gas volume flow is transferred to a cooling medium in a cavity of a disc body, so that the cooling medium at least partially evaporates.

The method for operating a rotary catalyst is used here to convert the enthalpy of a gas volume flow into mechanical energy.

In this embodiment it is correspondingly provided that a disk body forming the disk has at least one cavity in which a cooling medium, in particular a cooling liquid, is or can be accommodated for the purpose of cooling the disk body.

In an alternative embodiment of the method according to the invention for operating the rotary catalytic converter, heat from the gas volume flow is transferred to the cooling medium in the cavity of the disc body, so that the temperature of the cooling medium is increased, with the cooling medium essentially remaining in the liquid phase.

Furthermore, a device for converting chemical energy into electrical energy is provided according to the invention, comprising a combustion device for converting chemical energy into enthalpy of a fluid, and a rotary catalyst according to the invention, which is fluidically coupled to the combustion device, so that the combustion device provided fluid can be fed to the rotary catalytic converter with increased internal energy and the rotary catalytic converter can be driven with at least partial conversion of the internal energy of the fluid, and a generator which is coupled in a rotationally fixed manner to the rotary catalytic converter, so that mechanical energy made available by the rotary catalytic converter can be at least partially converted into electrical energy with the generator.

A further aspect of the present invention is a method for converting chemical energy into electrical energy, in which chemical energy is converted into enthalpy of a fluid by means of a combustion device and fluid with increased internal energy made available by the combustion device to a rotary catalyst according to the invention fluidically coupled to the combustion device is fed and this is driven with at least partial conversion of the internal energy of the fluid, wherein the rotary catalytic converter is used at the same time for the realization of a catalysis of at least one component of the inflowing fluid. Mechanical energy made available by the rotary catalytic converter is supplied to a generator which is coupled in a rotationally fixed manner to the rotating body of the rotary catalytic converter, so that mechanical energy made available by the rotary catalytic converter is at least partially converted into electrical energy by the generator. The particularly heterogeneous catalysis takes place in a rotating system that is able to transfer mechanical energy from the flue gas to a shaft. The shaft is coupled to a generator to generate electrical energy (see Fig. 1).

Thus, the invention can be operated as a device for the decomposition of nitrogen oxides, which result from the combustion of combustible gas or liquid fuel in internal combustion engines.

Ultimately, the present invention also provides a use of the rotary catalyst according to the invention for transferring kinetic energy of the inflowing fluid to the rotating body and at least temporarily for realizing a catalysis of at least one component of the inflowing fluids.

Different starting materials can be treated that react heterogeneously catalytically, such as in a reforming process:

CO ₊ _2H2O -> CH4 ₊ O2

_2C + O2 -> 2CO

Accordingly, the rotary catalyst is used here for the gasification of carbon in a circulatory system. Furthermore, the rotary catalyst can also be used for liquid products and educts, such as for the production of methanol, the splitting of liquefied plastics and for the production of artificial or synthetic combustion fuels and useful gases.

The invention is explained below with reference to the exemplary embodiments illustrated in the accompanying figures.

Show it:

Figure 1: an incinerator with rotary catalyst,

Figure 2: a first embodiment of the rotary catalyst in a sectional view,

FIG. 3: a shaft of the rotary catalytic converter shown in FIG. 2 in a sectional view,

Figure 4: A partial section of the rotary catalyst shown in Figure 2 in a partial section,

Figure 5: a second embodiment of the rotary catalyst in a sectional view, and

FIG. 6: a third embodiment of the rotary catalytic converter in a sectional view.

FIG. 1 shows a system which is used for the use of the rotary catalyst 6 according to the invention.

This system includes a device for supplying fuel 1 and air 2 to an internal combustion engine 4, which can in particular be part of a combined heat and power plant. Alternatively, the internal combustion engine 4 can also be a piston engine, such as a drive engine of a motor vehicle. Exhaust gas 3 is discharged from internal combustion engine 4 and fed to rotary catalytic converter 6 in order to use up the residual mechanical energy in exhaust gas 3 . The pressure at the outlet from the internal combustion engine 4 is set in such a way that it is possible to raise the temperature to around 130° C. downstream of the rotary catalytic converter 6, with the inlet temperature being 500° C. The pressure in front of the rotary catalytic converter 6 is around 2 bar and then around 1 bar. The additional electrical power gain is around 5%.

The rotary catalytic converter 6 in turn is mechanically coupled to a generator 8 by means of an output element 7 so that kinetic energy from the rotary catalytic converter 6 can be converted into electrical energy by the generator 8 . Exhaust gas 3 leaving the rotary catalytic converter 6 is discharged into the environment via a chimney 9 .

Accordingly, it is provided that the rotary catalytic converter 6 is fluidically coupled to the internal combustion engine 4 in order to convert kinetic energy of the exhaust gas 3 into electrical energy. At the same time, the rotary catalytic converter 6 enables a catalytic reaction in components of the exhaust gas 3.

FIG. 2 shows an embodiment of the rotary catalytic converter 6 in which a rotary body 10 is formed from a plurality of discs 11 . These disks 11 are arranged parallel to one another on a common axis of rotation 24 . In the present embodiment, the axis of rotation 24 is realized by an output element 7 in the form of a shaft. In the present embodiment, the disks 11 are coated or embodied on their outer sides at least in regions with a catalytically active material 12 . In particular, this catalytically active material 12 can be a noble metal, such as platinum, gold or silver. Optionally, this coating can be made porous. The type of coating is chosen so that there is no significant thermal influence on the fluid 29 .

The discs 11 are connected to this output element 7 in a torque-proof manner. The disks 11 are surrounded radially on the outside by a housing 20 which seals with the driven element 7, seals 47 only being visible in the embodiments according to FIGS. The housing 20 forms the gas receiving space 21 in its interior.

Fluid 29 in the form of flue gas can be introduced into the gas receiving space 21 along an inflow direction 23 and expanded there to the desired pressure and temperature value through an inlet device 22, as shown by way of example in FIG.

This results in a tangential flow towards the discs 11, as can be seen from FIG. 4, so that the discs 11 are rotated in the direction of rotation 28 shown in FIG.

As a result, the flue gas or fluid 29 also comes into contact with the catalytically active material 12, so that reduction reactions to break down nitrogen oxides in flue gas are carried out with the catalytically active material 12. From this, the double function of the rotary catalytic converter 6 can be seen, which uses the kinetic energy of the fluid 29 on the one hand, but also serves to remove nitrogen from the fluid 29 on the other.

If the catalytic layer or the catalytically active material 12 is selected in such a way that the pollutant system can achieve a sufficient denitrification effect on its own, the addition of reducing additives is not necessary.

In this case, the reduction is supported only by short transport distances in the gap between the discs 11 and by temperature and pressure, according to the SNCR principle. If these conditions cannot be set, a reducing additive is added at the entrance to the rotary catalytic converter 6, according to the SCR principle, e.g. by means of urea. The corresponding gross reaction equations are initially in words

Urea + water vapor from the flue gas ammonia and carbon dioxide, and in the form of an equation:

Ammonia is used as the actual reducing agent, resulting in molecular nitrogen and water vapor:

_4NH3 + 6NO -> 3N2 + 6H2O

On its own, the flue gas could also have a reducing and oxidizing effect when selecting a corresponding catalyst, if reducing material is available in a stoichiometrically oriented amount, as in the SNCR reaction, e.g

In Figure 2, the further flow of the fluid 29 is shown, namely from the radial outside of the disks 11 in the direction of the driven element 7. The driven element 7 comprises grooves 26 at several positions on its circumference, the axially extending channels in the shaft-shaped driven element 7 train. The grooves 26 are fluidically connected to the gas receiving space 21 so that fluid 29 flowing in the gas receiving space 21 can enter the respective groove 26 in the radially inner area of the discs 11 and be discharged axially to a flue gas collector 27 can. The fluid 29 can be fed to the chimney 9 according to FIG.

Figures 5 and 6 show two different embodiments of the rotary catalyst 6.

What both embodiments have in common is that the disks 11 each have a cavity 30 .

A cooling medium is located in the cavity 30, and it depends on the respective embodiment whether the cooling medium, which can be water in particular, is present as a liquid or as a vapor.

In the embodiment according to FIG. 5, the discs 11 are fluidically connected to one another via a plurality of connecting elements 40, which can be arranged in particular in uniformly distributed angular positions on the discs 11 or penetrating them.

A disc 41 shown on the far right in the embodiment according to FIG. 5 serves to increase the pressure by means of centrifugal force which acts on the cooling medium in the disc. For this purpose, the cavity 30 of this disk 11 is fluidically coupled to an inner cavity 45 of the driven element 7, so that in this embodiment water 31 can flow as a cooling medium into this cavity 30 of the right-hand disk. The water 31 flows via the connecting elements 40, which can also be referred to as distributors, along the illustrated flow path 34 into the other panes 11.

Due to the high temperature of the fluid 29 in the form of flue gas entering the gas receiving space 21, the water 31 in the disks 11 is heated. This produces steam 32 in the disks 11 in the embodiment according to FIG. 5. The rotation of the rotary body 10 or its disks 11, however, the denser water 31 or condensate is pressed into the radially outer area 36 of a respective disk 11, with the result that the steam 32 collects in the radially inner area 35 of a respective disk 11.

Merely for reasons of better explanation, only water 31 is shown in the right-hand pane 41, whereby it should not be ruled out that steam 32 can also exist in the cavity 30 due to the supply of heat.

Evaporation can lead to a significant decrease in the performance of the rotary catalyst 6 if too much internal energy is dissipated to the coolant becomes. Conversely, heat input due to condensation could lead to increased power output.

The steam 32 can be discharged via fluidic connections 46 between these cavities 30 filled with a steam-water mixture 33 and the inner cavity 45 of the driven element 7 . In order to prevent mixing of the entering water 31 via a feed 44 and the exiting steam 32 via a steam discharge line 42 , the driven element 7 has a separating element 42 separating its inner cavity 45 . In this way, the reduction reaction can be set in a targeted manner at any point on the disk surface.

The advantage of this embodiment is that the disks 11 can be cooled almost isothermally, so that they can be exposed to a high flue gas temperature over a long service life.

In the embodiment according to FIG. 6, the cavities 30 of the discs 11 are not fluidically coupled to one another. However, water 31 is also present in the cavities 30 as a cooling medium in this embodiment. Here, too, the supply of heat by the fluid 29 or flue gas results in partial evaporation, so that there is a zone of evaporation 50 along the radial direction from radially outside to radially inside, followed by a neutral area 51 and then a zone of condensation 52 trains. This means that in this embodiment, too, the denser condensate 60 is located radially on the outside in the cavities 30, and the water 31 or cooling medium in the form of steam 32 is radially on the inside Driven element 7, condensation occurs here. Due to the centrifugal forces acting on the condensate 60, the condensate 60 is transported radially outwards, as a result of which steam 32 located there is in turn pressed radially inwards.

The disks 11 used here are designed according to the principle of "heat pipes". These discs 11 cooled with cooling medium also have a comparatively long service life, even at very high temperatures, since the discs 11 can be kept at a desired temperature level by the cooling described. In this embodiment, too, the reduction reaction can be set accordingly in a targeted manner.

As already described in relation to the embodiment according to FIG. Reference List

1 fuel

2 air

3 exhaust

4 internal combustion engine

6 rotary catalyst

7 output element

8 generators

9 fireplace

10 bodies of revolution

11 disc

12 catalytically active material

20 housing

21 gas receiving space

22 inlet device

23 inflow direction

24 axis of rotation

25 outlet device

26 slots

27 flue gas collector

28 direction of rotation

29 fluids

30 cavity

31 water

32 steam

33 steam-water mixture flow path of the water

Radially inner area of the disc

Radially outer area of the disk

fastener

Disc for pressure increase

vapor discharge

separator

Feeding coolant internal cavity of the output element fluidic connection

poetry

Evaporation neutral zone

condensation

condensate

flue gas outlet

Claims

25 patent claims

1. Rotary catalytic converter (6), comprising a rotary body (10) for the flow of a fluid (29) and for the transfer of kinetic energy of the inflowing fluid (29) to the rotary body (10), the rotary body (6) having at least one surface area for Realization of a catalysis, in particular for the realization of a heterogeneous catalysis, at least one component of the inflowing fluid (29) is set up.

2. Rotary catalyst according to claim 1, characterized in that the surface of the rotary body (10) is formed at least partially by a catalytically active material (12) which is able to bring about reduction reactions for the breakdown of nitrogen oxides in the inflowing fluid (29).

3. Rotary catalytic converter according to one of the preceding claims, characterized in that the rotary body (10) has at least one disc (11 ) which can be set in rotation with the gas volume flow when the flow is essentially tangential, so that mechanical energy can be removed from an output element (7), in particular a shaft, coupled to the disk (11), and the rotary catalytic converter (6) has at least one gas receiving space (21) for receiving and discharging the gas volume flow flowing at least partially tangentially onto the disc (11).

4. Rotary catalytic converter according to claim 3, characterized in that a disk body forming the disk (11) has at least one cavity (30) in which a cooling medium, in particular a cooling liquid, is or can be accommodated for the purpose of cooling the disk body.

5. Rotary catalytic converter according to claim 4, characterized in that the disc (11) is set up to accommodate cooling medium in its cavity (30). Supplying heat from the gas volume flow flowing against the disc (11) to at least partially evaporate the disc (11) in the cavity (30).

6. Rotary catalyst according to one of Claims 3 to 5, characterized in that the rotary body (10) has a plurality of disks ( 11) which can be set in rotation with the gas volume flow when the flow is essentially tangential, so that mechanical energy can be removed from an output element (7) coupled to the disks (11), in particular a shaft, with cavities (30) in the disks (11) for the purpose of cooling the disc body, a cooling medium, in particular a cooling liquid, is or can be accommodated, and the cavities (30) of the discs (11) are fluidically connected to one another.

7. Rotary catalyst according to one of Claims 3 to 5, characterized in that the rotary body (10) has a plurality of disks (11) arranged on an axis of rotation (24) for converting the enthalpy of a gas volume flow as the inflowing fluid into mechanical energy of the rotary body (10). , which can be set in rotation with the gas volume flow when the flow is essentially tangential, so that mechanical energy can be removed from an output element (7) coupled to the discs, in particular a shaft, with cavities (30) of the discs (11) that are separated from one another in terms of flow for the purpose of cooling the disc body, a cooling medium, in particular a cooling liquid, is or can be accommodated.

8. Rotary catalyst according to one of the preceding claims, characterized in that the rotary body (10) has an at least regional coating with noble metal or an alloy based thereon.

9. Rotary catalyst according to one of the preceding claims, characterized in that the rotary body (10) is formed at least in sections from graphene.

10. Rotary catalyst according to one of the preceding claims, characterized in that the rotary body (10) is formed at least in a portion of its outer surface of zeolite. ti

11. Method for operating a rotary catalytic converter (6) according to one of claims 1 to 10, in which the rotating body (10) of the rotary catalytic converter (6) is flown with a fluid (29) and thereby kinetic energy of the inflowing fluid (29) on the body of revolution (10), wherein at least part of the time the body of revolution (10) carries out catalysis, in particular heterogeneous catalysis, of at least one component of the inflowing fluid (29) with at least one surface area.

12. Method for operating a rotary catalytic converter according to claim 11, characterized in that the inflowing fluid (29) is a gas volume flow and heat of the gas volume flow is transferred to a cooling medium in a cavity (30) of a disc body, so that the cooling medium at least partially evaporates.

13. Device for converting chemical energy into mechanical energy, comprising a combustion device for converting chemical energy into enthalpy of a fluid, and a rotary catalyst (6) according to any one of claims 1 to 10, which is fluidically coupled to the combustion device, so that from the combustion device provided fluid (29) with increased internal energy can be fed to the rotary catalytic converter (6) and the rotary catalytic converter (6) can be driven with at least partial conversion of the internal energy of the fluid (29), as well as a generator (8) which is rotationally fixed to the Rotary catalyst (6) is coupled, so that from the rotary catalyst (6) provided mechanical energy with the generator (8) is at least partially convertible into electrical energy.

14. A method for converting chemical energy into electrical energy, in which chemical energy is converted into the enthalpy of a fluid (29) by means of a combustion device and fluid (29) made available by the combustion device with increased internal energy is subjected to a rotary catalyst fluidically coupled to the combustion device ( 6) is supplied according to one of claims 1 to 10 and this is driven with at least partial conversion of the internal energy of the fluid (29), wherein the rotary catalyst (6) is used at the same time to implement catalysis of at least one component of the inflowing fluid (29), and mechanical energy made available by the rotary catalytic converter (6) is supplied to a generator (8) which is rotationally fixed to the rotary body (10) of the rotary catalytic converter (6). 28 is coupled, so that mechanical energy made available by the rotary catalytic converter (6) is at least partially converted into electrical energy with the generator (8).

15. Use of a rotary catalytic converter (6) according to one of claims 1 to 10 for transferring kinetic energy of the inflowing fluid (29) to the rotating body (10) and at least at times at the same time for realizing a catalysis of at least one component of the inflowing fluid (29).