EP1377649A1

EP1377649A1 - Installation and method for producing energy using pyrolysis

Info

Publication number: EP1377649A1
Application number: EP02708128A
Authority: EP
Inventors: John E. E. Sharpe; Jack R. Metz; Reinhard W. Serchinger
Original assignee: Gautschi Ulrich
Current assignee: Gautschi Ulrich
Priority date: 2001-04-12
Filing date: 2002-04-11
Publication date: 2004-01-07
Anticipated expiration: 2022-04-11
Also published as: EP1377649B1; ATE331011T1; WO2002083815A1; DE50207297D1

Abstract

The aim of the invention is to achieve a good energy balance, in particular in small energy-production installations, in which combustibles containing carbon are exploited by means of pyrolysis. To achieve this, the installation comprises: a) a reaction section provided with at least one pyrolysis zone for exploiting the combustible, b) at least one combustion device, used to burn the gas obtained by pyrolysis to form flue gas, c) supply means for supplying the gas from the pyrolysis zone to the combustion device, d) conduit means, in which the burning gas and the resulting flue gas can be conducted from the combustion device to a gas outlet point, e) a thermal utilisation device, which is used to convert at least one portion of the thermal energy that is released by the combustion process into a useful form of energy that can be output by the installation, using a heat exchanger, whereby f) the burning gas and/or the resulting flue gas is guided past the pyrolysis zone (8) and at the same time past at least one section of the heat exchanger (28a), in relation to the direction of flow, by means of one section of the conduit means (26), and whereby the heat exchanger (28a) absorbs the thermal energy of the gases in a first area (40) and in a second area (41) releases said energy into a medium of the thermal utilisation device.

Description

Plant and method for generating energy by pyrolysis

The invention relates to a system and a method for generating energy, as described in the preambles of claims 1 and 12.

It has long been known that waste or residues can be used energetically with pyrolytic processes. Residual materials include, for example, municipal and industrial waste, recycling sorting waste, waste and residual wood, sewage sludge, animal meal, etc. The pyrolytic processes are based on a degassing of the carbon-containing residues intended as fuels which is carried out at high temperatures and essentially with the exclusion of oxygen. The energy contained in the resulting gases can be burned, e.g. Oxidation that convert gases into thermal energy. Thermal energy is comparatively easy to use, for example to generate heat, cold or electricity.

Various system concepts have already been proposed in order to obtain usable energy by pyrolytic recycling of residual substances. One of the first ^' plant concepts has become known as "Thermoselect". This provides for degassing the residues in a temperature range from 450 ° C to 550 ° C. The remaining or partially charred residues from this process then enter a carburetor part of the plant, in which they are gasified with the supply of natural gas and oxygen at 1200 ° C to 2000 ° C. The synthesis gases are then cooled in a wet process and after various cleaning stages for energy generation and with a partial flow for heating the pyrolysis zone The disadvantage of the system is its high level of complexity. Due to the high technical effort required for the process that can be carried out with this plant, only large plants with approx. 100,000 tons of residues per year seem to be profitable.

Another process, known under the name Carbo-V process, provides for primarily wood-containing residues to be broken down into their volatile and solid components in a first reactor by partial oxidation. The solid components, mainly coal containing coke, are ground. In a second stage, the resulting very tar-containing gas is re-oxidized in the upper part of a combustion chamber, while in the lower part of the combustion chamber the coke dust is converted into raw gasification gas. This gas is cooled and cleaned several times together with the first stage synthesis gas. The cleaned gas is then used to generate useful energy. With this method, the complex wet cleaning can be seen as a disadvantage. The system required for this process must also be relatively large and complex for economical operation. In addition, this process is essentially only intended for the energy recovery of wood.

Another concept is shown in EP 0 874 881 B1. Only solid fuels should be used here. The solid fuels are subjected to gasification after pyrolysis in a pyrolysis zone of the plant, with the addition of catalytically active substances. The gases obtained through both pyrolysis and gasification are then burned, with some of the energy obtained from the combustion initially being used to heat the pyrolysis zone with radiant heat. The combustion gases are then passed to another part of the plant in the flow direction of the gases behind the pyrolysis zone in order to use the energy content remaining in the gases there. This system can be seen as disadvantageous in that a great deal of effort is required to isolate those parts of the system in which the combustion gases are conducted at high temperatures. In addition, it has been shown that this system concept only leads to economic results if it can be used to implement comparatively large systems, for example in the order of magnitude of large 10 MW thermal output.

The invention is therefore based on the object of providing a generic system and a method which enable a good energy balance even with a small system size.

This object is achieved according to the invention in a system of the type mentioned at the outset in that the combusting gas and / or the resulting flue gas by means of a section of the line means, and in relation to their direction of flow, at the same time that they pass the pyrolysis zone essentially also at least one Section of a heat exchanger are passed, the heat exchanger absorbing thermal energy of the gases in a first region and delivering it to a medium of the heat utilization device in a second region. The object is also achieved by a method as described in claim 12.

In systems according to the invention, it is therefore provided that a section of a stream of hot combustion or flue gases generated during the combustion is not - as in the prior art - exclusively supplied in succession to different recycling purposes, but preferably already during the combustion and immediately thereafter essentially simultaneously is used both for heating the pyrolysis zone and for delivering thermal energy to a heat exchanger. Essentially irrespective of how this is implemented in a constructive manner, at least a considerable part of the insulation previously required can thereby be omitted. On the contrary, it is provided according to the invention that in the section of the conduit means in which heat transfer to the pyrolysis zone takes place, a further heat transfer should take place, namely a heat transfer at the heat exchanger. In contrast to the prior art, this part of the conduction means should advantageously have a particularly good thermal conductivity.

It is preferred here that predefined physical conditions are created by coordinating the heat transfer at the heat exchanger with the heat transfer to the pyrolysis zone. This is said to be able to reliably maintain the temperature prevailing in the pyrolysis zone at a value which is favorable for pyrolysis within a certain temperature range. This temperature range can be, for example, from 850 ° C to 950 ° C. By knowing the temperatures of the flue gases or the burning gases, their quantity and the geometrical design of the pipe means, the pyrolysis zone and the heat exchanger, such conditions can be set by a suitable choice of material. As a result, the amount of energy contained in the flue gases is available for the heat exchange process, which exceeds the amount of energy required to heat the pyrolysis zone.

It has been shown that the temperature of the combustion gases during combustion or immediately thereafter in a range from approximately 1000 ° C. to 1200 ° C., preferably from 1050 ° C. to 1150 ° C. and particularly preferably approximately 1100 ° C. , is on the one hand to have good results in the pyrolysis process and on the other hand to have a sufficient amount of energy available for the production of useful energy. This temperature range has also proven to be particularly advantageous since these temperatures, on the one hand, there is certainly no recombination of the combustion or flue gases to form dioxins and furans. On the other hand, the temperatures are high enough to carry the flue gases over a longer distance in the pipe means before they cool down to temperatures at which such recombinations could be feared in significant quantities.

Due to the immediate use of the thermal energy released by the combustion, both for pyrolysis and for heating a heat exchange medium of the heat utilization device, particularly low loss energies occur in systems according to the invention. This significantly increases the energy balance of such a system and also enables the operation of small systems in terms of size and the amount of energy gained. However, this advantage can also be used to generate a larger usable amount of energy with the same plant size as a conventional plant.

In order to heat both the pyrolysis zone and the heat exchanger at the same time in a structurally simple and inexpensive manner with a section of a volume flow of flue gases, in a preferred embodiment, a flow space for the can be between a first boundary surface and a second boundary surface of a section of the conduit opposite the first boundary surface Gases are formed. The pyrolysis zone should adjoin the first boundary surface and the second boundary surface should be part of the heat exchanger.

It has proven to be particularly favorable if the pyrolysis zone has at least one essentially elongated tube which is surrounded by an annular conduit means, the longitudinal extension of which can run essentially parallel to the longitudinal extension of the pyrolysis tube. in this connection For example, an (outer) wall of the pyrolysis tube can also function as the inner wall of the conduit, which enables particularly good heat transfer to the pyrolysis zone. On the other hand, an outer wall of the conduit can be designed as a heat exchanger, which also enables particularly good heat transfer to the heat exchange medium with very little heat loss. This also makes it possible to implement a system according to the invention with a particularly low design effort.

In a preferred embodiment, the pyrolysis tube and the conduit are each circular with respect to their cross-section, the conduit being able to surround the pyrolysis tube concentrically. In other embodiments, a plurality of pyrolysis tubes can also be arranged in a conduit which is annular in cross section, the cross-sectional shapes of the conduit and the pyrolysis tubes being able to be optimized with regard to good heat transfer. Basically, the cross-sectional shapes of the tubes can be chosen almost arbitrarily.

In a further preferred embodiment, the heat exchanger delivers the energy to a water boiler or boiler, in which water vapor is generated, which in turn can be used to generate a usable form of energy, such as heat, cold or electricity. With regard to good heat transfer and to avoid insulation material for the line means, it can be advantageous here if the line means and thus also the heat exchanger are arranged completely within the water boiler over at least a portion of the line means. This can have the consequence that the pyrolysis zone, at least over a section along a conveying path of the fuel through the pyrolysis zone, is completely within the heat exchanger and thus also the heat exchange medium. In a further preferred embodiment, the system according to the invention can be provided with a control circuit in which one or more parameters of the water vapor emerging from the boiler are measured. These measurement results can be used to regulate the quantity of residues or fuel fed into the pyrolysis tube so that the values of the steam parameters can be set as essentially constant.

In order to be able to manufacture different plants according to the principle of the invention, for example with regard to the size of the plants, with a particularly low design and manufacturing outlay, these should be of modular construction. This means that the systems can be provided with predefined interfaces at which system components can be connected to one another by means of preferably detachable connections. This also makes it possible to adapt existing systems to changed conditions quickly and with little effort.

Further preferred embodiments of the invention result from the dependent claims, the description of the figures and the figures.

The invention is explained in more detail with reference to an embodiment shown schematically in the figures; show it:

1 shows a basic structure of a possible system according to the invention;

2 shows a cross-sectional illustration of a ring burner of the system according to the invention;

Fig. 3 is a longitudinal sectional view of another possible embodiment of a ring burner. Fig. 4 shows a cross section along the line X of Fig. 1 through a pyrolysis tube and part of a heat exchanger.

1 shows a plant according to the invention for converting residual materials into energy. The plant has an input point 1, in which residues 2 can be placed in an intermediate silo 3 of the plant. The intermediate silo 3 is used for the intermediate storage of residues 2 before they are fed to the recycling described in more detail below.

A conveyor wheel 4 arranged in a downpipe connects to a lower funnel-shaped end of the intermediate silo. The conveying wheel 4 and / or the residues 2 stored in the silo 3 are essentially airtight on this side of the system. The downpipe opens into the latter in the area of one end of a horizontally oriented pipe 5. A rotary screw conveyor 6 is arranged in the tube 5 and conveys the residual materials 2 into the area of the other end of the tube 5. Here there is an opening in the tube 5 through which the residues pass via a further downpipe 7 into a region of a front end of a pyrolysis zone designed as a pyrolysis tube 8. Also arranged in the pyrolysis tube 8 is a rotatably drivable screw conveyor 9 with which the

Residual substances 2 are conveyed from an inlet opening 8a to a lower outlet opening 8b provided at the other end of the pyrolysis tube. The pyrolysis tube 8 is sealed against air entry. The preferably essentially anaerobic pyrolysis process results in temperatures of approximately 850 ° to approximately 950 ° C., preferably approximately 900 ° C., in the interior of the pyrolysis tube.

The last-mentioned end of the pyrolysis tube opens into a silo-like container 10 in which a gasification chamber 11 is located below the pyrolysis tube 8 and a gas chamber above it. Mixing chamber 12 is formed. Like the pyrolysis tube 8, the gasification chamber 11 also belongs to a reaction part of the system. The residues 2, which have passed through the pyrolysis tube 8 and an essentially anaerobic pyrolysis, thus fall due to the force of gravity through the outlet opening 8b of the pyrolysis tube 8 down into the gasification chamber 11 provided with a lower funnel-shaped end. The funnel-shaped end finally opens into another pipe 14 with screw conveyor 15, through which the end products of the gasification process, essentially ash or slag, can be removed from the system in a predetermined amount and time. An arrow 16, 17, 18 indicates three possible introductions with which, alternatively or cumulatively, water vapor (with a temperature of approx. 300 ° C.), recirculated exhaust gas (with a temperature of approx. 200 ° C.) and / or one Oxygen / nitrogen mixture preheated to approx. 200 ° C can be introduced into the gasification chambers. This enables gasification of the already pyrolysed residues or fuels at temperatures of approx. 750 ° C to 850 ° C, whereby the gases hydrogen (H ₂ ) and carbon monoxide (CO) can be released, for example.

The gasification chamber 11 is connected to the outlet opening 8b of the pyrolysis tube 8 and bypass channels arranged on both sides thereof around the pyrolysis tube with the gas mixing chamber 12. The gases formed in the pyrolysis tube, for example methane and carbon monoxide, can thus also escape upward through the outlet opening 8b into the gas mixing chamber 12.

Via a feed line 20 connected to the gas mixing chamber 12, the gas mixing chamber is connected to a burner 21 having a ring burner. The combustion device 21 is arranged over the entire circumference of the pyrolysis tube 8 around the latter. The in Fig. 2 in In a first exemplary embodiment, a ring burner, shown in more detail in a cross-sectional illustration and arranged laterally directly next to the gas mixing chamber, has a plurality of burners 22, for example eight burners, at least one burner, evenly distributed over the circumference of the line means. In a manner not shown, each of the burners 22 is connected to the supply line 20 for gas supply. The burners 22 can be oriented such that the gas flowing out of them and initially burning in a flame 24 has a predetermined flow direction component 25 or a flame direction that is tangent to the pyrolysis tube 8, so that the pyrolysis tube is heated as evenly as possible , FIG. 2 shows that this enables the flame 24 of each burner 22 to be aligned with the flame 24 of the burner 22 that follows on the circumference. This can be achieved safely and in a structurally simple manner that the individual burners 22 of the ring burner ignite each other.

The stream of gases still burning and the flue gases already generated by the combustion can preferably also have a flow direction component which runs parallel to the longitudinal extension 8c of the pyrolysis tube 8 - and in fact opposite to the flow direction of the fuels 2 in the pyrolysis tube. 3 shows such an embodiment of a combustion device 21, in which the flame direction 25 of the individual burners 22 is inclined and directed towards the longitudinal axis 8c of the pyrolysis tube. As can be seen in particular in this illustration, a line means 26, which is described in more detail below, is closed at its end 26a in the region of the combustion device 21. Extreme positions of the individual burners 22 are shown in FIGS. 2 and 3. The burners 22 in FIG. 2 are aligned completely tangentially to the pyrolysis tube 8, the orientation of the flames 24 having no component parallel to the longitudinal axis 8c of the pyrolysis tube. 3, on the other hand, the direction of the flames 24 has no tangential component. As a result, the flame direction 25 lies in a sectional plane through the longitudinal axis 8c of the pyrolysis tube. In other embodiments, not shown, the individual burners of the combustion device can also assume any position between the extreme positions shown in the two figures, which can be achieved, for example, by pivoting the burners shown in FIG. 2 through an angle of less than 90 °.

As can be seen in FIG. 1, a start / support burner 27 is provided in the peripheral region of the ring burner, with which the ring burner can be ignited on the one hand. For this purpose, the flame (not shown) generated by the start / support burner 27 can be directed at at least one of the burners 22 of the ring burner. On the other hand, the start / support burner 27 can also be used if the ring burner supplies too little energy. The start / backup burner 27 can be supplied by an external fuel supply.

In the exemplary embodiment of FIGS. 1 and 2, the ring burner can be integrated into the line means 26 at one end thereof. The conduit 26 can initially be designed as a tube 28 that is ring-shaped in cross section and runs essentially in a straight line. The annular tube 28 is arranged concentrically around the pyrolysis tube 8. As a result, the concentric tube 28 surrounds the pyrolysis tube 8 over its entire length, the longitudinal axes of the two tubes being identical. In order to enable good heat transfer from the annular tube to the pyrolysis tube, these have a common tube wall 29 made of a material with good thermal conductivity. ability on. Metallic materials, such as alloy steel and cast steel, are particularly suitable for this.

The annular tube 28 merges at an end opposite the combustion device 21 into a first curvature region 30 with a deflection angle of 180 °. In the region of curvature 30, the one volume of the conduit element is fanned out into a plurality of individual straight and parallel tubes that run both to one another and to the annular tube 28. For the sake of simplicity, this plurality of tubes is shown as only a single tube 31 in FIG. 1. The fanning out can increase the total area where heat transfer can take place. At an end of the tubes 31 opposite the first curvature region 30 there is a second curvature region 32. Here too the conduit is deflected by 180 ° and into a further enlarged number of individual tubes 33 running parallel to one another (likewise as a single tube). provided) divided. A third curvature region 34 then adjoins this in the direction of flow, by again increasing the number of individual tubes. The conduit means runs from the third curvature region 34 to a so-called quenching means 36, which is provided for the shock cooling of the flue gases.

As can be seen from FIG. 1, the previously described meandering section (reference numerals 28 to 34) of the conduit means 26 is located approximately from the combustion device 21 to the third curvature region 34 in a closed boiler 37 filled with water. This portion of the conduit means and Boiler 37 thus form a so-called three-pass boiler, which is used for heat recovery. At an upper end of the boiler 37, a water vapor line 38 is connected to it. This turns the water vapor generated due to the heating of the water into one Device 39 guided, in which the energy content of the water vapor is used to generate useful energy, for example electricity, heat or cold. Said section (28 to 34) of the conduit means 26, in particular the (outer) jacket of the annular tube 28, which is shown in more detail in FIG. 4, thus serves as a heat exchanger 28a with which part of the energy content of the burned gases guided in the tube 28 is transferred to the Water of the three-pass boiler is released. Here, the heat exchanger 28a absorbs thermal energy from the hot gases on an inner surface 40 of the tube 28 and releases it to the water on an outer surface 41 of the tube 28. The same section of the volume flow of the gases simultaneously releases another part of its thermal energy to the pyrolysis tube 8 on an outer surface 42 of the tube wall 29. This part of the thermal energy can be used to heat the contents of the pyrolysis tube via an inner surface 43 of the tube wall 29 by radiant heat or by heat transfer.

With the quenching device designated 36 in FIG. 1, the flue gas is released within a very short time, for example within 0.2 seconds. from about 450 ° C to about 200 ° C, cooled. For this purpose, for example, water can be injected into a chamber through which the flue gases are also carried out. The quenching process avoids recombinations of the flue gases to form dioxins or furans, or at most permits them to an acceptable degree. In a further section 44 of the conduit means 26, the flue gases cooled in this way arrive at a flue gas cleaning device 45 known per se. This has filters with which particles are removed from the flue gas stream. The filtrate, essentially filter dust, is collected in a container 46 for subsequent removal.

The flue gas thus cleaned now leaves the flue gas cleaning device 45 and arrives via a further outlet. cut 48 of the line means to a vacuum means designed as a suction fan 49. The induced draft fan 49 on the one hand conveys the flow of the cleaned flue gas to a flue gas outlet point provided as a chimney 50. On the other hand, the suction-draft fan 49 generates a negative pressure at its installation point in the conduit means 26, which can act as far as the intermediate silo 3 in a direction opposite to the direction of flow. The negative pressure causes an essentially constant volume flow of the flue gases through the conduit means 26 which are sealed off against the entry of air. It can also be provided that the oxygen required for the combustion in the area of the combustion device 21 solely because of the negative pressure also acting in the combustion device or at least with its support is sucked in. The negative pressure can also be used to convey the gas from the gas mixing chamber 12 to the combustion device 21.

The system can also be provided with a control device, not shown in the drawing, with which the parameters of the water vapor emerging from the boiler 37 are set as essentially constant. For this purpose, parameters of the steam, such as pressure, quantity and temperature, can be measured in the area of the steam outlet, which is why 38 temperature, quantity and pressure sensors can be present at one or more points in the steam line.

The measured values can then be used to influence the amount of substances entered into the pyrolysis tube 8. For example, if the steam parameters fall or are already too low, the entry of residues can be increased in a predetermined manner. It can also be provided that the start / backup burner is also switched on. By means of this regulation, depending on the conditions actually present in a system according to the invention, for example the heat transfers and the amounts of material to be pyrolized, the combustion temperature of the gases is approximately from 1050 ° C. to 1150 ° C. , The temperature is preferably kept as constant as possible within this range, for example at approximately 1100 ° C. This makes it possible to create temperature conditions that are as constant as possible even in the pyrolysis tube in a range from 850 ° C. to 950 ° C. in order to set the usable amount of energy available per time unit at the steam outlet point as constant as possible.

Claims

claims

1. Plant for energy production, in which a pyrolytic recycling of carbon-containing fuels takes place, comprehensive

a reaction part provided for recycling the fuel, which is provided with at least one pyrolysis zone in which a gas can be obtained by pyrolysis,

at least one combustion device with which the gas obtained in the pyrolysis can be burned with the addition of oxygen, as a result of which flue gas is produced,

Supply means for supplying the gas from the pyrolysis zone into the at least one combustion device,

Conducting means in which the burning gas and the resulting flue gas can be guided from the combustion device to a gas outlet point, the condensing means being able to pass the burning gas and / or the resulting flue gas past the pyrolysis zone by the thermal energy obtained with the combustion to heat the pyrolysis zone,

a heat utilization device with which at least some of the thermal energy released by the combustion can be converted into a useful energy form to be released by the system using a heat exchanger,

characterized in that the burning gas and / or the resulting flue gas by means of a section of the conduit means (26), with respect to the direction of flow, at the same time as it is bypassed the pyrolysis zone (8) essentially also at least a section of a heat exchanger 28a), the Heat exchanger (28a) absorbs thermal energy of the gases in a first area (40) and releases this to a medium of the heat utilization device in a second area (41).

2. Installation according to claim 1, characterized in that a flow space for the gases is formed between a first boundary surface and a second boundary surface of a section of the conduit means (26) opposite the first boundary surface, the pyrolysis zone (8) being adjacent to the first boundary surface and the second boundary surface is part of the heat exchanger (28a).

3. Installation according to one or both of the preceding claims, characterized in that at least the section of the conduit means (26) is designed as an annular tube (28) which surrounds the pyrolysis zone (8) and an outer wall (29) of the annular tube ( 28) is part of the heat exchanger (28a).

4. Plant according to one or more of the preceding claims 1 to 3, characterized in that the section of the conduit means (26) is arranged such that at least one component of the flow direction of the gas runs parallel to the longitudinal extent of the pyrolysis zone (8).

5. Plant according to claim 4, characterized in that at least the component of the flow direction is oriented substantially opposite to a flow direction of the fuel in the pyrolysis zone.

6. Plant according to one or more of the preceding claims, characterized by a gasification zone arranged in the region of one end of the pyrolysis zone, in which gasification of already pyrolyzed fuels takes place by supplying oxygen and / or oxygen-old substances.

7. Plant according to claim 6, characterized in that the gas is fed from the pyrolysis zone together with the gas obtained in the gasification zone with the feed means of the combustion device.

8. Installation according to claim 7, characterized in that in relation to the direction of flow of the flue gases between the heat exchanger and the gas outlet point, a negative pressure means for generating a negative pressure in the conduit means is arranged.

9. Plant according to claim 8, characterized in that the vacuum means is designed as a suction fan.

10. Plant according to one or more of the preceding claims, characterized in that the heat exchanger is designed as a multi-pass boiler, in particular as a two- or three-pass boiler.

11. Plant according to one or more of the preceding claims, characterized by a modular structure, in the functional modules of the plant by releasable connections fertilize attachable to the system and can be removed by loosening the connections from the system.

12. A method for energy production, in which a pyrolytic utilization of carbon-containing fuels takes place, comprising

an entry of fuels into at least one pyrolysis zone in which pyrolysis can be carried out,

combustion of the gas obtained by pyrolysis with the addition of oxygen, which produces flue gas,

a forwarding of the resulting flue gas from the combustion device in the direction of a gas outlet point, the burning gas and / or the resulting flue gas being able to be guided past the pyrolysis zone by means of a conduit in order to use the thermal energy obtained with the combustion device to heat the pyrolysis zone, and the gases can be guided past a heat utilization device with which at least a part of the thermal energy released by the combustion can be converted into a useful energy form to be emitted by utilizing a heat exchange process,

characterized in that

a flow of the burning gas and / or the resulting flue gas in the flow direction in a section of the conduction means is passed substantially simultaneously past the pyrolysis zone and at least a section of a heat exchanger, the heat exchanger absorbing thermal energy of the gases in a first area and this in one second area to a medium of the heat utilization device.

13. The method according to claim 12, characterized in that the flue gases are guided past both the pyrolysis zone and the heat exchanger in the first section of the conduit and flow exclusively along the heat exchanger in a second section.

14. The method according to one or both of the preceding claims 12 and 13, characterized in that the medium is water and water vapor is generated by the heat exchange process.

15. The method one or more of the preceding claims 12 to 14, characterized in that a negative pressure is generated in the line means, which is used to generate a flow of the flue gases.

16. The method according to claim 15, characterized in that the negative pressure is used to promote the gases intended for combustion to a point in the system at which the combustion is carried out.

17. The method according to one or more of the preceding claims 12 to 16, characterized in that the fuels are introduced into a gasification chamber after passing through the pyrolysis zone and gas is obtained by gasification with the addition of oxygen or oxygen-containing substances.

18. The method according to claim 12, characterized by a control step in which a parameter dependent on the heat exchange process is measured and the entry of fuels into the system is varied on the basis of this measurement.