EP1991641A1

EP1991641A1 - Process and device for generating gas from carbonaceous material

Info

Publication number: EP1991641A1
Application number: EP07703488A
Authority: EP
Inventors: Jörg KEMPER; Frank Lohmann
Original assignee: NATIVE POWER SOLUTIONS GmbH and Co KG
Current assignee: ME MUENSTERLAND ENERGY GmbH
Priority date: 2006-02-17
Filing date: 2007-02-16
Publication date: 2008-11-19
Also published as: DE102006007458B4; CA2642590A1; BRPI0706811A2; WO2007093428A1; AR059536A1; DE102006007458A1; US20100154728A1

Abstract

For gasifying carbonaceous material (2) to form CO and H<SUB>2</SUB>-containing gas (23), the drying and/or the heating and the pyrolysis of the carbonaceous material (2) is carried out using microwave irradiation (32) and heat radiation and thereafter the pyrolysis products (21, 22, 25) and/or the carbonaceous material (2) are/is gasified. For this the carbonaceous material (2) is irradiated in a microwave station (3) with a heating unit and then passed on into a reactor (4) for the gasification. The gasification takes place using a steam-plasma source (5).

Description

Method and apparatus for producing gas from carbonaceous material

The present invention relates to a method and apparatus for producing CO and H ₂ -containing gas from carbonaceous material. Further, the invention relates to a device for generating electrical energy by pyrolysis and gasification of carbonaceous materials to CO and H ₂ -containing gas with a gasification reactor, a powered by the CO and H ₂ gas-containing engine and a motor-driven power generator.

Against the backdrop of decreasing resources of fossil fuels, decentralized energy supply based on waste or biomass from renewable raw materials is becoming increasingly important. In biomass or waste incineration, heat is generated, e.g. for heating buildings or water. During gasification, in addition to heat, fuel gas is generated, which can be used in engines for power generation.

The gasification generally takes place in several steps: drying / heating for preparation, pyrolysis and gasification, namely the reaction of the pyrolysis products by oxidation and reduction. The resulting gas contains i.a. Hydrogen, carbon monoxide and methane, which can serve as fuel. The

The composition of the resulting gas depends on the reaction gas used and the temperature at which the gasification takes place. At higher temperatures, the concentration of hydrogen and carbon monoxide increases and decreases the concentration of methane.

The higher the temperature, the lower the likelihood that the resulting gas will still contain toxic or carcinogenic components such as dioxin or tar. Because at temperatures of 900 ⁰ C and higher, they are split into innocuous, volatile substances such as carbon dioxide and hydrogen. One way to high temperatures of 900 ⁰ C and to provide more, provides the use of a plasma torch.

From DE 32 33 774 A1 discloses a method and a plant for gasification of carbonaceous material to a mainly consisting of CO and H ₂ gas mixture are known in which the carbonaceous material is input in particulate form in a shaft furnace to a predetermined level. The shaft furnace has plasma torches on the ground on. In addition to heat energy through the plasma torch and oxidant in the form of O ₂ , CO ₂ or H ₂ O is supplied. As a result, the carbonaceous material is subjected to a high temperature under oxidizing conditions. The volatiles are then released and react with the oxidizer. The non-volatile part, however, is coked. Oxidizer that has not reacted with the volatiles may react further down in the shaft furnace with the coke produced and additionally form CO and possibly H ₂ O. Upwardly escaping CO ₂ and H ₂ O can react with the carbonaceous material falling down to CO and H ₂ . The gas leaving the shaft furnace has a maximum temperature of 1500 ^° C. The temperature on the surface of the granular material in the shaft furnace can reach approximately 2000 ^° C.

An object of the present invention is to provide a method and an apparatus in which the carbonaceous material is pretreated.

This object is achieved by a method for gasification of carbonaceous material to CO and H ₂ -containing gas with upstream pyrolysis, wherein the pyrolysis of the carbonaceous material by means of microwave irradiation and by heating the carbonaceous material is carried out and that the gasification of the pyrolysis allotherm with Help a water vapor plasma is performed.

By coupling energy via microwaves into the carbonaceous material, it is achieved that the carbonaceous material is completely penetrated with little effort and heated rapidly from the inside to the outside. With moisture-containing carbonaceous material is also achieved that it is sufficiently dried and the moisture is converted into water vapor, which then when gasifying

Oxidizing agent is available. Since the carbonaceous material is heated from the inside to the outside, combustion is suppressed, and instead the carbonaceous material is pyrolytically split into volatile carbon compounds and non-volatile carbon compounds with shorter carbon chains. Conventional heating means may be used to preheat the carbonaceous material from outside to inside or reheat it after or parallel to microwave irradiation. The heat input from the inside to the outside and from the outside to the inside reduces the time required for as complete pyrolysis as possible and overall improves the energy balance of the entire process. The pyrolysis products serve below as starting materials for the gasification, which is faster and more efficient due to the already at least partially carried out pyrolysis. A significant advantage of the method according to the invention is that it can be used particularly well in small-scale systems for decentralized energy supply. Because by the pre-treatment by means of microwaves, for example, even household waste or biomass in the form of garden waste without consuming previous

Processing be used. Namely, the drying and heating as well as the pyrolysis are achieved largely or completely by the microwave irradiation. Also, a heating unit to support pyrolysis can be provided with only a small footprint.

Depending on the process parameters, in particular temperature and reactants, the gasification can take place auto- or allothermic. In order to ensure as complete a gasification as possible, the gasification is carried out here by means of external heat input and indeed by a plasma. Because with the help of a plasma can easily reach temperatures at which it is ensured that residues of tar or harmful compounds are split and in particular CO and H _{2 are} converted. According to the invention, a water vapor plasma is used: it consists of O, H, OH, O ₂ , H ₂ and H ₂ O radicals which react very well with the pyrolysis products and, if appropriate, not yet pyrolyzed carbonaceous material. In addition, the enthalpy density of water vapor plasma is very high. These

Properties lead to an acceleration of the gasification process. In addition, since the thermal efficiency of steam plasma sources is 70-90%, the use of steam plasma is economical in operation. The use of both pure water vapor plasma and plasma from water vapor with additives or from gas mixtures with water vapor as a reaction accelerator is advantageous.

In a preferred embodiment, a pore burner is used for heating during pyrolysis. Pore burners are particularly well suited because they provide a very high power density and can also be operated with the synthesized gas produced according to the present process and still hot. This leads to an improved overall energy balance of the process.

In a very particularly preferred embodiment, the gasification immediately follows the pyrolysis. This allows the pyrolysis products to be further treated immediately by gasification before they cool so that they can be brought to the gasification process temperature in a minimum of time. This improves the Total energy balance of the process. Incidentally, in comparison with conventional methods, the use of a vapor plasma for gasification and the particularly efficient pyrolysis by the combination of microwave irradiation and thermal irradiation make it possible to dispense with complicated separation of the material flow into solid and volatile pyrolysis products.

In a preferred embodiment, the pyrolysis products and / or the carbonaceous material and / or gasification products will be at least partially exposed more than once to external heat input in the form of a water vapor plasma. This increases the efficiency of the gasification process. Material particles, be it pyrolysis products or possibly unreacted starting materials of carbonaceous material, which were not completely gasified on the first passage through a zone with external heat input, do so in a renewed passage through such a zone. In addition, they promote the heat transfer to newly supplied material particles, which also increases the gasification efficiency. The

For example, particles may be passed via a blower or mechanically so as to be re-exposed to the external heat input. When using a plasma source for generating the external heat input, they are preferably sucked by utilizing a nozzle effect to the plasma. They thus come directly into the hot plasma flame, resulting in a large increase in volume of the gaseous fractions. This increase in volume results in an acceleration towards further pyrolysis products leaving the microwave irradiation and / or leaving carbonaceous material. The particles coming from the plasma flame mix with the newly coming from the microwave irradiation shares, they heat quickly and accelerate the gasification process.

It has proven to be advantageous to densify the carbonaceous material before and / or during and / or after microwave irradiation. The compaction leads to a more efficient energy input by microwave irradiation or heat radiation and is preferably carried out before the microwave irradiation and / or optionally the heat radiation. As a result, as complete as possible pyrolysis of the carbonaceous material is achieved by the microwave irradiation.

In particular, but not only when the carbonaceous material has been compacted, the pyrolysis products and / or the carbonaceous material after

Microwave irradiation advantageously comminuted. This will change the surface of the gasifying material increases, which leads to a further acceleration of the gasification process. In addition, the overall energy balance is improved. Because unlike the crushing of the starting material before pyrolysis, which may require quite a lot of energy, the solid pyrolysis products, which are mostly coal, can be crushed with relatively little effort and energy.

In another aspect of the present invention, the object is achieved by an apparatus for gasifying carbonaceous material to CO and H ₂ containing gas having at least one microwave station and a heating unit to at least partially perform the pyrolysis of the carbonaceous material, and a first Having reactor with at least one steam plasma torch to perform the gasification. As an advantageous side effect in the microwave station, the carbonaceous material is also dried and / or heated if necessary by the microwave and heat radiation and not only broken up the molecular structures. The pyrolysis products are then converted particularly energy efficiently in the steam plasma in synthesis gas with a high hydrogen content. Because when using steam plasma torches, in addition to the heat energy, necessary oxidizing agent is also made available with the plasma.

In a particularly preferred embodiment, the microwave station or the heating unit is arranged in the process flow direction immediately before the first reactor. This not only increases the energy balance of the device, but also allows a particularly compact construction of the device, so that it is well suited for decentralized energy supply.

For the purpose of optimized pyrolysis on the one hand and optimized gasification on the other hand, the microwave station is preferably arranged in a second reactor.

Advantageously, the microwave station has a compression unit. Depending on the embodiment, the compression unit of the microwave station or the heating unit upstream of, integrated into it or downstream of her. The integration into the microwave station is particularly suitable when irradiated simultaneously with microwaves and / or heated and compacted by radiant heat. In particular, the compression unit allows a more compact design of the microwave station, which can be thermally insulated with less effort. Particularly preferably, the heating unit is designed as a pore burner. In addition to the energy input via microwave irradiation, an efficient heat input is thereby ensured by thermal radiation, which acts from outside to inside on the material to be pyrolyzed, in addition to the effect of the microwave irradiation from the inside to the outside. In contrast to conventional burners, such as gas burners, significantly higher temperatures can be achieved with pore burners, which leads to a much higher heat input.

Advantageously, a mixing unit is arranged in the first reactor. It serves to mix the content already present in the first reactor with the content added from the microwave station or the heating unit. As a result, the added content is brought faster to gasification temperature and the gasification process accelerated. Preferably, the mixing unit is designed as a rotatable sieve drum, which also sifts out the ash.

In a preferred embodiment, a comminution unit is arranged in the first reactor or at the outlet of the microwave station or the heating unit. It serves to comminute the solid pyrolysis products and / or the carbonaceous material after microwave irradiation. This increases their surface area and accelerates gasification. Preferably, the shredding unit is designed as a scraping unit that scrapes off the surface of the pyrolysis products and / or the carbonaceous material that emerge from the microwave station or heating unit. During the scraping operation, the scraping unit releases the gasification process temperature to the fresh scraping point of the scraped off material by direct contact. In this way the energy input into the material particles is accelerated. In addition, the scraper creates a cracked surface, which further enlarges the gasification surface. Particularly preferably, the crushing device is arranged on the screen drum, so that the scraped particles are immediately mixed by the movement of the screen drum with the already existing reactor contents.

In a preferred embodiment, the at least one steam plasma torch is connected to the first reactor such that its plasma flame does not or only partially reaches into the interior of the reactor, and leads an additional line from the first reactor to the plasma flame. As a result, reactor contents are sucked to the plasma flame, by strong heating and consequent Volume enlargement of the gaseous portion is accelerated into the reactor inside. In the plasma flame itself, a proportion of material is gasified in particular CO and H ₂ and by the acceleration of the material in the reactor interior, the mixing is promoted in the reactor interior, thereby accelerating the gasification process. Since gas-particle mixture is constantly sucked out of the interior of the reactor through the additional line to the plasma flame in a type of nozzle effect, a continuous gasification process is maintained. The advantage of this recirculation system is not only that the gasification process takes place much faster, thereby shortening the residence time of the material. The reactor space can also be dimensioned significantly smaller, with the result that the insulation losses are greatly reduced and the

Overall efficiency increases. The flow of the material can also be maintained mechanically or with the aid of a fan or assist the nozzle effect.

Further, the object is achieved by a device for generating electrical energy by pyrolysis and gasification of carbonaceous materials to CO and H ₂ -containing gas with a gasification reactor, a powered by the CO and H ₂ gas-containing engine and a motor-driven power generator, wherein the gasification reactor is preceded by at least one microwave station and a heating unit in which the carbonaceous material is at least partially pyrolyzed by means of microwave irradiation and heat radiation, and wherein the gasification reactor has a water vapor plasma burner as the heat source. By coupling such a device for gasifying carbonaceous material to CO and H ₂ -containing gas with a motor that uses the generated CO and H ₂ -containing gas to generate electricity, can be used without much effort and energy efficient carbonaceous materials such as household waste, organic waste , Garden waste, pellets, etc. or industrial waste not only in heat energy and chemical energy, which is stored in the CO and H ₂ -containing gas, convert, but directly into electrical energy.

Advantageously, the heating device is designed as a pore burner.

In a particularly preferred embodiment, the microwave station or the heating unit is arranged in the process flow direction immediately before the first reactor.

In a preferred embodiment, the engine is preceded by a hot gas burner and the engine is designed as a Stirling engine. In this way, the gas produced without extensive cooling, which would be necessary in conventional gas engines, directly continue to use, whereby the overall efficiency of the device for generating electrical energy is increased. In addition, Stirling engines have the advantage of being relatively low vibration, so that the noise level is correspondingly low. This is contrary to the use, especially in smaller building or residential units.

Preferably, the hot gas burner is designed as a pore burner. This has the advantage that the allowed inlet temperature of the gas is still so high that disturbing impurities such as e.g. Tar is still in the volatile state. Thereby, the cost of cleaning the generated gas can be reduced to a minimum, which allows a particularly compact and energy-efficient design of the device for generating electrical energy.

The present invention will be explained in more detail with reference to a preferred embodiment. Show this

Figure 1 is a perspective view of a first embodiment of a

Apparatus for generating gas;

Figure 2 is a horizontal section through the device of Figure 1;

3 shows a vertical section in the longitudinal direction through the device

Figure 1 in a simplified view;

Figure 4 is a vertical section perpendicular to the longitudinal direction through the device of Figure 1 in a simplified view;

Figure 5 is a schematic detail view of a first embodiment of a

Scraping unit;

Figure 6 is a schematic detail view of a circulating air duct;

FIG. 7 schematically shows the material flow of a gasification;

Figures 8a, b is a schematic detail view of a second embodiment of a scraping unit from the side and in plan view; 9 shows a horizontal section through a device as in FIGS. 1 to 4 with the scraping unit from FIGS. 8a, b;

Figures 10a, b is a schematic representation of a particular embodiment of the scraping unit of Figures 8a, b;

Figures 11a, b, c views of a further embodiment of a device for power generation in perspective from the front and from the rear and from the side;

FIG. 12 shows a section through a further embodiment of a device for producing gas;

Figure 13 is a perspective view of a third embodiment of a gas generating apparatus;

FIG. 14 shows a horizontal section through a device as in FIG. 13;

Figure 15 is a vertical longitudinal section through the device of Figure 13 in a simplified view;

FIG. 16 shows a vertical section through the device from FIG. 13 at the level of the pyrolysis pore furnace;

17 shows a horizontal section through a device as in FIG. 13 with the scraping unit from FIGS. 8a, 8b; and

Figure 18 is a vertical section perpendicular to the longitudinal direction through the device of Figure 10 in a simplified view.

1 shows a gas generator 1 on a support 108, which is designed for a power of about 100 kW _e ι (net). The starting material may be industrial or household waste or biomass based on renewable raw materials, such as garden waste, wood chips, preferably a grain size of about 6-20 mm, sawdust, pellets, peel, husks or straw. Even fossil fuels can be gasified in the gas generator. The carbonaceous material is filled through the hopper 100. Using the waste heat of a gas cooler 10 in the form of a heat exchanger, possibly combined with a gas scrubber, the carbonaceous material 2 there already preheat to about 60 ° -80 ° C (see also reference 201, Figure 7).

With the aid of a screw conveyor 102 (see also FIGS. 2, 3) with drive 104, the carbonaceous material 2 is conveyed further into a secondary reactor 6. There, the carbonaceous material 2 is heated to about 400-500 ° C. This is done predominantly by microwaves generated in the microwave generator 31 and a heater 62 which utilizes the waste heat of the primary reactor 4 in which the gasification is taking place or externally energized, e.g. as an electric oven, or uses a combination of internal and external energy. The heater 62 is connected to the reactor 6 and connected upstream of the microwave generator 31.

In addition, the carbonaceous material 2 is passed through a crimping part 61 surrounded by the heater 62. The crimping part is conical, with its cross section tapering in the conveying direction. As a result, the carbonaceous material 2 is compressed airtight before the microwave zone 32.

By the heater 62, the carbonaceous material 2 is heated from the outside inwards. Due to the microwave radiation in the microwave station 3, the carbonaceous material 2 is penetrated and heated from the inside to the outside. This combination of supplied radiant heat and microwave irradiation leads to the best possible heat input into the carbonaceous material 2.

Due to the heat input, the carbonaceous material 2 is also dried. This is particularly advantageous in non-pretreated starting materials such as industrial or domestic waste or garden waste, but also generally in biomass from renewable resources. The gas generator 1 is therefore insensitive to larger ones

Variations in the moisture content of the carbonaceous material 2. The moisture exits as water vapor from the carbonaceous material 2 and serves as an oxidizing agent in the gasification process.

The high heat input, in particular into the interior of the carbonaceous material 2 by the microwave irradiation, triggers the pyrolysis of the carbonaceous material 2. at The pyrolysis, among other things, the longer-chain molecules of the carbonaceous material 2 are split into shorter molecules. Volatile and non-volatile pyrolysis products form, which are used as starting materials for the subsequent gasification. In order to implement the energy input by microwave irradiation more targeted, the carbonaceous material 2 is passed through a feed tube 33, so that the entire carbonaceous material 2 is guided through the microwave zone 32. In particular, when pellets or similar biomaterial are used as the starting material 2, the molecular structures are virtually broken by the microwave irradiation, whereby the pyrolysis proceeds more efficiently. The airtight compression in the pinch part 61 in front of the microwave zone 32 ensures that as far as possible no nitrogen from the ambient air enters, which would reduce the calorific value of the generated CO and H ₂ containing gas.

The dimensioning of the microwave generator 31 depends in particular on the extent of the microwave zone 32, the density of the carbonaceous material 2 and the desired temperature. The choice of frequency may be limited by government regulations. For example, In Germany, only the frequencies 24.25GHz, 5.8GHz, 2.45GHz and exceptionally 915MHz are approved for microwave heating. Instead of a microwave generator, it is also possible to use two, three or more, wherein either one coherent microwave zone or several separate microwave zones can form.

The feed tube 33 leads into the primary reactor 4, in which also a plasma torch 5 opens and in which the gasification takes place. The feed tube 33 passes through a sieve drum 42 arranged in the primary reactor 4. The sieve drum 42 is rotatably mounted about its longitudinal axis and is rotated via the drive 106. In the present example, the longitudinal axis of the screen drum 42 is parallel to the feed tube 33. Screen drum pockets 43 are arranged on the circumferential wall of the screen drum 42 (see in particular FIG. 4). In addition, on the side facing the plasma torch 5 side of the screen drum 42, a scraper 7, here in the form of five blades 71, mounted, which are carried along with the screen drum 42, thereby passing the exit of the feed tube 33 and the surface of the exiting material, ie the non-volatile pyrolysis products 21 and possibly the not yet fully pyrolytically reacted starting material 2, scrape off, whereby small particles 25 are formed (see also Figure 5). In particular, the already completely pyrolyzed material is very brittle, so it can easily crumble. In addition to the surface enlargement by particle formation itself, the process of scraping leads to a cracked and therefore particularly large Surface available for the gasification process, allowing the gasification process to proceed much faster and more efficiently.

FIG. 12 shows a section through a further embodiment of a gas burner, perpendicular to the feed tube 33. In this example, for more intensive pyrolysis, the microwave station is combined with a porous burner 63, which adjoins the microwave generator 31 and is adapted in its geometry in that it encloses the feed tube 33. Since pore burners are made of ceramic, their geometries are relatively freely selectable. The present arrangement with the pore burner 63 enclosing the feed tube 33 is i.a. advantageous because of the small footprint. By the

Pore burner 63 protrudes into the reactor 4 or optionally also completely arranged in the reactor 4, it contributes to a warm-up of the reactor 4, in particular in the initial phase of the gasification process. The pore burner 63 may be fired with CO and H ₂ -containing gas produced in the gas generator. Since pore burners allow very high gas temperatures, gas generated during the gasification process can be supplied to it without prior cooling, possibly after dust filtration. In the example shown in FIG. 12, the porous burner 63 achieves a heat input that is six times higher than that of a conventional gas burner. Overall, the use of a pore burner in combination with the microwave pyrolysis improves the overall energy balance of the gas burner with still small footprint and is therefore particularly suitable for gas generators that are sized for home use.

Opposite the outlet of the feed tube 33, the hot gas stream 23 of the plasma burner 5 opens into the primary reactor 4. Therefore, the scraped off particles 25 are exposed directly to the hot gas stream 23. In addition, the blades 71 of the scraping unit 7 constantly pass through the hot gas stream 23, so that they also have the process temperature of about 950 ° -1050 ° C and leave the direct contact with scraping this temperature to the supplied pyrolysis products 21 and possibly the carbonaceous material 2 , As a result, the particles 25 in the shortest possible time to process temperature and can be gasified. The temperature of 950 ⁰ C and more in the gasification zone ensures that even harmful carbon compounds and tar are completely gasified as possible and also the content of CO and H _{2 in} the gasification product is as high as possible.

Turbulences prevail in the hot gas stream, leading to a rapid mixing of the scraped off particles with the remaining reactor contents, ie with the reactants for lead the gasification. As a result, the gasification takes place faster and more intensively, whereby the overall efficiency is increased. Particles 25, which sink in the reactor interior and remove from the hot gas stream 23, are collected by the screen drum 42 in their compartments 43, transported back to the hot gas stream and poured there in the hot gas stream, so that they are better available again for gasification. The entire reactor contents are constantly circulated, which further promotes gasification.

A further embodiment of a scraping unit is shown in detail in FIGS. 8a, b and as part of the gas generator in FIG. It is a rotating scraper 72, which is arranged at the outlet of the feed tube 33. The scraping part 72 consists of a ceramic disk with windows 75 arranged on the front side. In contrast to the scraping unit 7 with blades 71 which is driven via the screening drum 42, the rotating scraping part 72 is driven via a shaft 73. Due to the rotational movement of the non-volatile pyrolysis 21 particles 25 are scraped off. These fly through the frontal windows 75 from the feed tube 75 into the hot gas stream 23 of the

Plasma torch 5. Since the volatile pyrolysis products as well as the water vapor already formed during drying also have to escape through the windows 75 from the feed tube 33, intensive gasification already takes place in the region of the windows 75, which act like small reactor chambers. As a result, the overall efficiency of the gas generator 1 is further increased.

A particular embodiment of a rotating scraping part is shown in FIGS. 10a, b. The rotating scraping part 72 'has radially arranged windows 74 in addition to the windows arranged on the front side. It rotates in the feed tube 33 and is driven as above via the shaft 73.

The drive 105 of the rotating scraping member 72 'consists essentially of a drive bushing 81, which is rotatably mounted in a housing (not shown). The rotational movement takes place in the present example, a sprocket 87. Likewise, but also a gear, a toothed belt, a V-belt or the like can be used. The shaft 73 is guided radially in the drive bush 81, but can move axially. At the right end of the shaft 73 is positively and / or positively secured a driving star 82 and secured by screw 86. The driving star 82 engages in circularly arranged grooves in the drive bushing 81. As a result, the rotational movement of the drive bush 81 transmits to the shaft 73. Axially, the driving star 82 can move within the grooves. The axial movement is to the right by a rear Travel limit 83, which is bolted to the drive sleeve 81, limited. To the left, the axial movement against the force of a spring 84 to the end of the grooves in the drive bushing 81 is possible.

FIG. 10a shows the normal operation of the rotating scraping part 72 '. As it rotates, the follower 82 is located at the rear travel limit 83 and the radial windows 74 are covered by the walls of the delivery tube 33. In FIG. 10b, the axial pressure on the rotating scraping member 72 'increases due to impending clogging of the delivery pipe 33. If the axial force of the rotating scraping member 72' exceeds the force of the spring 84, the rotating scraping member 72 'moves leftward out of the drawing

Feed tube 33 and thus releases the radially arranged windows 74. Nonvolatile pyrolysis products 21 can now escape from the feed tube 33 through the windows 74 and prevent their clogging.

By a sensor 85 in the region of the drive bush 81, the axial position of the driving star 82 can be defined and thus counteracted via a control of the input variables "speed of the scraper" and "speed of material supply" the risk of clogging. In addition, the displacement measurement of the driving star 82 allows a determination of the state of wear of the rotating blade part 72.

Plasma torch 5 in the present example is a steam plasma torch. The composition of the steam plasma promotes the gasification process very strongly, which consists of the radicals O, H, OH, O ₂ , H ₂ and H ₂ O at a mean temperature in the range of 4000 ⁰ C and peak values in the core of the plasma flame of approx. 12000 ⁰ C. The enthalpy density of water vapor is very high and the thermal efficiency of water vapor sources is 70% -90%. In addition, water vapor is readily available. Water vapor plasma therefore not only has an accelerating effect on the gasification process, but is also advantageous for economic reasons.

In order to further reduce the residence time of the particles 25 in the reactor 4 until the gasification is as complete as possible, a primary recirculating air channel 41 is provided on the reactor 4 (see in particular FIGS. 3, 6). The primary recirculating air 41 connects the lower portion of the reactor 4 with the nozzle 52 of the steam plasma torch in the upper region of the reactor 4. The energy density of the plasma flame 51 is above the primary

Umluftkanal 41 a mixture of befindlichem in the reactor 4 gas 22, 23 and particles 25 from sucked in the lower reactor area. The mixture of a temperature of about 750 ⁰ C gets so a kind of nozzle effect directly into the 4000 ⁰ C hot steam plasma flame 51, resulting in a large increase in volume of the gas. This increase in volume results in an acceleration of the gas mixture in the direction of reactor 4 with strong turbulence. The inlet cross section into the reactor 4 is conically designed as a diffuser 52 in order to enhance this process. In addition, secondary recirculating air channels 44 are additionally provided, which guide particles 25 from the upper interior of the reactor 4 into the diffuser 52. Again, the nozzle effect is exploited again. With the help of the secondary recirculation channels 44, in addition to the action of the primary circulating air channel 41, better mixing of the reactor contents in the upper reactor space is achieved. In addition, in the plasma flame 51 and its immediate surroundings, the gasification proceeds very intensively due to the particularly high temperatures and the high radical density.

Apart from the utilization of the nozzle effect, this recirculation principle could also be achieved mechanically or with the aid of fans, or these measures could be combined with the nozzle effect. This will be decided by the person skilled in the art depending on the geometry of the device, the operating parameters of the plasma source 5 or other external heat input sources.

In the reactor 4, the mixture of gas and particles leaving the diffuser 52 strikes the scraping device 7 and the surface of the supplied pyrolysis products 21, possibly also of the carbonaceous material 2, and heats them to the process temperature. Subsequently, the mixture flows into the lateral upper region of the screening drum 42 and mixes with the material constantly conveyed up through the sieve drum. This not only maintains a continuous gasification process. This gasification process also speeds up the gasification process.

All of these measures lead to a very greatly reduced residence time of the material to be gasified. As a result, in particular the primary reactor 4 can be dimensioned significantly smaller, with the result that the insulation losses are greatly reduced and the overall efficiency can be significantly increased. The size of the gas generator can be reduced so much that in addition to systems in the power range of about 100 kW _e ι (net) and more small systems for the living area in the power range of about 2-4 kW _e ι (net) are possible (see below, Figures 11a-c). The ash 24 produced during the gasification is screened off through the sieve drum 42 and falls into the lowermost region of the primary reactor 4 (see, inter alia, FIG. 4). There is an ash outlet 114, through which the ash 24 is discharged (reference numeral 203 in Figure 7). The remaining gasification products 23 are withdrawn via the lower reactor region by means of a slight negative pressure by means of a blower 128 from the reactor interior to a filter unit 112. Advantageously, these are ceramic filter candles 1 13, which may be integrated into the reactor housing. The ceramic filter candles 1 13 serve as a dust filter and have the advantage that the gas produced without prior cooling, so at about 700 ° -800 ° C can be filtered.

The filter unit 112 and the reactor 4 share in the present example, an outer wall (see Figure 4). This has the particular advantage that, on the one hand, the reactor 4 is particularly well insulated on this side and on the other hand, the filter unit 112 is preheated by the reactor heat to operating temperature. In addition, the filter unit 112 and the reactor 4 divide the ash outlet 114, which simplifies the cleaning of the filter unit 112.

After filtering, the generated hot gas for power generation could be fed directly to a hot gas engine or even to a pore burner. In the present example, the hot gas is passed via a line 122 to another station 120, which has the function of a gas-water heat exchanger and / or a scrubber. This allows the hot gas to cool to below 50 ⁰ C and clean. In addition, the heat can be used by the heated cooling water, which is fed via the input 116 and the output 118 is derived, is fed by means of a pump 126 in the building technology or forwarded to an external heat exchanger. The heat can also be used for preheating the carbonaceous material 2. The cooled clean gas is withdrawn by means of the blower 128 via a negative pressure from the system and removed for further use in an external gas storage or a combined heat and power plant.

FIGS. 11 ac show another embodiment of a gas generator. This gas generator is designed for a power of about 2-4 kW _e ι or 8-16 kW _therm and is therefore suitable for use in the living area. Since the internal structure of this gas generator does not differ significantly from the already explained gas generator 1, an interior view is dispensed with and only deviating from it

Components with which the gas generator is connected in this example. FIGS. 11a-c show a house installation 10 for generating heat and electrical energy. The house system 10 is a complete module, which consists essentially of a gas generator and an associated motor as a generator drive. As described above, the house system generates via pyrolysis with the aid of the microwave generator 31 and a heating unit and gasification not visible here via subsequent external heat input, here by means of a water vapor plasma source CO and H ₂ containing gas from carbonaceous materials. This gas is used to drive a Stirling engine 131 that drives a generator 132, thereby generating power. The waste heat is used to heat residential buildings and generate hot water.

Through the nozzle 99, the carbonaceous materials are supplied by means of, for example, blowers or screws and get into the here double-walled funnel 101. After pyrolysis with microwave and heat radiation and steam plasma gasification as described above, the CO and H ₂ containing gas with a temperature of about 400 ⁰ C from the filter unit 112 of ceramic filter cartridges and is guided through the gas pipe 122 in the hot gas burner 143, here in the form of a pore burner. There it is burned in the hot gas burner 143 with the supply of combustion air, which is sucked in by a blower 141 for reducing noise via an inlet nozzle 140. The supply of combustion air is previously conducted through the here double-walled ash tray 204, which heats the air and cools the ash. This minimizes the risk of fire during ash disposal. From the ash tray 204, the combustion air is fed via the line 142 to the hot gas burner 143.

The heat energy generated in the hot gas burner 143 (about 1050 ° -1100 ° C) is used to drive the Stirling engine 131. This drives the generator 132, so that power is generated. The dissipated energy resulting from the Stirling process is introduced via a cooling water outlet 135 in a water / water heat exchanger 134. The cooled water (.DELTA.T about 40-50 ⁰ C) is introduced via the cooling water inlet 136 back into the Stirling engine 131. The hot exhaust gases (about 600-700 ⁰ C) from the hot gas burner 143 are fed via a line 137 a gas / water heat exchanger 133. After flowing through the gas / water heat exchanger 133, the exhaust gases übe a line 138 in the hopper 101 and heat there introduced through the nozzle 99 carbonaceous materials. Via a pipe connection 139, the exhaust gases come with a temperature of around 50 ⁰ C in the smoke outlet of the building. The waste heat from the heat exchangers 133, 134 is fed via a cooling water inlet 116 and a cooling water outlet 118 in the building heating and hot water treatment.

The advantages of the house 10 can be seen in the fact that carbonaceous materials such as pellets, green waste, household waste, etc. can be used to power residential buildings. In addition to the required space heating and hot water treatment, electricity is generated, which is fed into the grid during rest periods and remunerated. This reduces the energy costs of individual households and contributes to

Decentralization of the electricity market. Due to the compact size of the gas generator, devices from the size of multi-storey heating systems up to apartment blocks can be realized. By the combustion of the gas with temperatures over 500 ⁰ C no tar can precipitate, so that the gas cleaning can be limited to the dust filter 1 12 by means of ceramic filter candles.

The third apparatus for producing gas shown in FIG. 13 differs from the first apparatus shown in FIG. 1, in particular with regard to the design of the pyrolysis station. While in the first device, the material to be pyrolyzed after compaction is first heated with the aid of the heater from outside to inside, before it is irradiated with microwaves to heat it from the inside out (see also Figures 2 and 3), is in the third device, the material to be pyrolyzed first irradiated with microwaves of the microwave generator 31 to reach the inside of the pyrolysis, and then by a heater, in this example, a pore furnace 63, out to bring the material also from the outside to the pyrolysis temperature ,

FIG. 16 shows a vertical section through the device from FIG. 13, specifically at the level of the pore burner 63. In contrast to the example shown in FIG. 12, in this example, for a more intensive pyrolysis, the microwave station has three

Combined pore burners 63 which connect to the microwave generator 31 and are arranged around the feed tube 33 in the region of the lower circumference, so that the radiant heat 66 radiates onto the feed tube 33. The pore burner 63 may be fired with syngas generated in the gas generator and containing CO ₂ and H ₂ , which is supplied via the synthesis gas ports 64. The synthesis gas is combined with air or oxygen in the pore region of the pore burner 63 to generate heat energy burned. The resulting exhaust gases exit through the discharge outlet 65 and can be used for preheating other components. The pore area is generally formed of ceramic foam or other high temperature resistant structure. Particularly advantageous for pore burners is their very high power density of about 1000 kW / m ² . In particular, high temperatures of up to about 1400 ⁰ C can be achieved. Further advantages are high heating rates and good controllability of the oven temperature. Since pore burners allow very high gas temperatures, gas generated during the gasification process can be supplied to them immediately without prior cooling, if necessary after dust filtration. In the example shown in FIG. 16, the porous burner 63 achieves a heat input that is six times higher than that of a conventional gas burner. Overall, the use of a pore burner in combination with the microwave pyrolysis improves the overall energy balance of the gas burner with still small footprint and is therefore particularly suitable for gas generators that are sized for home use.

Furthermore, in the gasification reactor 4 of the third device (see FIG. 14), there are some differences from the first device: The feed tube 33 for supplying the pyrolyzed material and the plasma torch 5 are arranged relative to one another such that the hot gas flow generated by the plasma flame 51 is not only laterally but frontally on the scraper unit 72 (see also Figures 8a, b) meets to heat the scraper unit 72 even better. During scrape, the scraper unit 72 transfers its temperature to the material to be shredded. Due to the frontal alignment of the hot gas flow 23 to the scraper unit 72, it is additionally achieved that the hot gas flow in the frontal windows 75 of the scraper unit 72 also directly heats the material to be shredded to the process temperature for the gasification.

The heating of the pyrolysis immediately after pyrolysis, even if they are due to the pore burner at a very high temperature, leads to the fact that already takes place in the feed tube 33 to the gasification reactor side exit gasification already. Also in the frontal windows 75 of the Schabeineinheit 72 already partial gasification takes place.

The advantage of this smooth transition from pyrolysis to gasification is that the solid pyrolysis products are gasified very efficiently and little ash remains. Therefore, in the second device shown here, the drum 45 is not designed as a screen drum, but only as a drum 45 with drum compartments 43 (see Figure 15), to still not gasified particles 25 bring back into the hot gas stream. The few ash 24 can exit via the end faces of the drum 45 and be discharged via the ash outlet 1 14. The non-perforated drum 45 has the additional advantage of more efficient thermal insulation of the interior of the gasification reactor 4.

The plasma flame 51 is arranged in the second device in a diffuser 52 provided with openings 53 (see FIG. 14). In the water vapor plasma flame 51, the volatile and solid pyrolysis products come together with the radicals generated there, with which they react to CO and H ₂ . In addition, they are heated very rapidly in the plasma very rapidly, so that a sudden volume expansion takes place, leading to a local

Negative pressure leads. Through the openings 53, more pyrolysis products are sucked into the water vapor plasma flame 51 via this local underpressure, so that a continuous flow of hot gas is maintained.

By shortening the feed tube 33 and the intrusion of the plasma torch 5 into the gasification reactor 4 in comparison to the first device, the space required is further reduced in the third device.

It should be noted that the third apparatus for producing gas from FIGS. 13 to 16 can also be implemented with the scraping unit 72 'as in FIGS. 8a, b or else with blade 71 as in FIG. 4 or another scraping unit. It is also possible to provide the third device completely without comminution unit, as shown in FIGS. 17 and 18. Depending on the choice of the carbonaceous material, the solid pyrolysis products that are present here due to the particularly efficient pyrolysis can be so crumbly that additional comminution is unnecessary. In addition, by directly striking the pyrolysis products as they enter the reactor 4, the hot gas stream 23 is brought to a sufficiently high temperature for low-residue gasification in a minimum of time.

It should also be noted that the third apparatus for producing gas has also been described in a power generation apparatus such as with reference to FIGS. 11 ac. REFERENCE CHARACTERS

1 gas generator

10 house plant

2 carbonaceous material

21 non-volatile pyrolysis products

22 volatile pyrolysis products

23 hot gas flow

24 ash

25 scraped off particles

3 microwave station

31 microwave generator

32 microwave zone

33 feed tube

4 primary reactor

41 primary recirculation channel

42 sieve drum

43 screen drum compartment

44 secondary recirculation channel

45 drum

5 plasma torches

51 plasma flame

52 diffuser

53 opening

64 gas connection

65 exhaust gas outlet

66 radiant heat

6 secondary reactor

61 pinch piece

62 heating

63 pore burners

7 scraping unit

71 blade

72, 72 'rotating scraper

74 radially arranged window

75 frontally arranged window 81 Drive book

82 driving star

83 rear limit

84 spring

85 sensor

86 screw connection

87 sprocket

99 nozzles

100 funnels

101 funnel (exhaust gas flow)

102 transport screw

104 Drive screw conveyor

105 drive rotating scraper

106 Drive sieve drum

108 edition

110 heat exchanger / scrubber

112 filter unit

113 ceramic filter candle

114 ash outlet

116 cooling water inlet

118 cooling water outlet

120 clean gas outlet

122 gas line

124 Infeed in building technology / external heat exchanger

126 pump

128 blowers

130 external gas storage / combined heat and power plant / engine

131 Stirling engine

132 generator

133 gas / water heat exchanger

134 water / water heat exchanger

135 cooling water outlet

136 cooling water inlet

137 line

138 line

139 pipe connection 140 inlet nozzle

141 blowers

142 combustion air line

143 Preheat hot gas burner 201

203 ash dump

204 ash tray

Claims

claims

1. A method for gasifying carbonaceous material to CO and H ₂ -containing gas with upstream pyrolysis, characterized in that the pyrolysis of the carbonaceous material by means of microwave irradiation and by

Heat radiation of the carbonaceous material is carried out and that the gasification of pyrolysis products is carried out allothermally with the aid of a water vapor plasma.

2. The method according to claim 1, characterized in that the heat radiation of the carbonaceous material is carried out by means of a pore burner.

3. The method according to claim 1 or 2, characterized in that the gasification is directly connected to the pyrolysis.

4. The method according to any one of claims 1 to 3, characterized in that the pyrolysis products and / or the carbonaceous material and / or gasification products are at least partially exposed to the water vapor plasma more than once.

5. The method according to any one of claims 1 to 4, characterized in that the carbonaceous material is compacted before and / or during and / or after the microwave irradiation.

6. The method according to any one of claims 1 to 5, characterized in that the pyrolysis products and / or the carbonaceous material are comminuted after the microwave irradiation.

7. A device for gasifying carbonaceous material to CO and H ₂ -containing gas, characterized in that it comprises at least one microwave station (3) and a heating unit (62, 63) to at least partially perform the pyrolysis of the carbonaceous material, as well as a first reactor (4) with at least one steam plasma torch (5) to perform the gasification.

8. The device according to claim 7, characterized in that the microwave station (3) or the heating unit (62, 63) in the process flow direction immediately before the first reactor

(4) is arranged.

9. Apparatus according to claim 7 or 8, characterized in that the microwave station (3) in a second reactor (6) is arranged.

10. Device according to one of claims 7 to 9, characterized in that the microwave station (3) has a compression unit (61).

11. The device according to claim 10, characterized in that the heating unit is designed as a pore burner (63).

12. Device according to one of claims 7 to 11, characterized in that in the first reactor (4) a mixing unit (42) is arranged.

13. The apparatus according to claim 12, characterized in that the mixing unit is designed as a rotatable screen drum (42).

14. Device according to one of claims 7 to 13, characterized in that in the first reactor (4) or at the output of the microwave station (3) a comminution unit (7) is arranged.

15. The device according to claim 14, characterized in that the comminution unit is designed as a scraping unit (7), the surface of the pyrolysis products (21) and / or the carbonaceous material (2), or emerge from the microwave station (3), scrapes.

16. The apparatus of claim 13 and 14 or 15, characterized in that the crushing device (7) on the screen drum (42) is arranged.

17. Device according to one of claims 7 to 16, characterized in that the at least one steam plasma torch (5) is connected to the first reactor (4) such that its plasma flame (51) not or only partially into the reactor interior ranges, and an additional line (41) from the first reactor (4) to the plasma flame (51), is sucked through the reactor contents to the plasma flame (51).

18. Device for generating electrical energy by means of pyrolysis and gasification of carbonaceous materials to CO and H ₂ -containing gas with a Gasification reactor, a powered by the CO and H ₂ gas-containing engine and a motor-driven current generator, characterized in that the gasification reactor (4) at least one microwave station (3) and a heating unit (62, 63) are connected upstream, in which carbonaceous material is at least partially pyrolyzed by microwave irradiation and heat radiation, and that the

Gasification reactor (4) as a heat source has a steam plasma torch.

19. The apparatus according to claim 18, characterized in that the heating device is designed as a pore burner.

20. The apparatus according to claim 18, characterized in that the microwave station (3) or the heating unit (62, 63) is arranged in the process flow direction immediately before the first reactor (4).

21. Device according to one of claims 18 to 20, characterized in that the motor (131) is preceded by a hot gas burner (143) and the engine is designed as a Stirling engine (131).

22. The apparatus according to claim 21, characterized in that the hot gas burner is designed as a pore burner (143).