EP1436364B1 - Device for producing a combustible gas mixture - Google Patents

Abstract

The invention relates to a device for producing a combustible gas mixture from a carbon-containing starting material, especially from pieces of wood, said device comprising a supply unit (2) for supplying the starting material to a reactor (1). Said reactor comprises at least one oxidation zone (10) for the oxidation of the starting material, and a reduction zone (11) for reducing at least one intermediate product of the oxidation. Any kind of wood of coniferous trees and/or of deciduous trees, such as maple, alder, spruce or pine, can be used with said device, the device ensuring a continuous or automatic supply as well as high operational safety and relatively high quality of the combustible gas mixture. According to the invention, this is achieved by the fact that the supply unit (2) is arranged in the horizontal direction next to the reactor (1) and comprises at least one storage device (4) for the intermediate storage of the starting material.

Description

The invention relates to a device for producing a combustible gas mixture from a carbon-containing starting material, in particular from lumpy wood, according to the preamble of claim 1.

State of the art

Wood gasifiers have been used for motor combustion for decades. For example, in 1923 the descending gasification plant was developed in direct current, the so-called "Imbert wood gas plant". Corresponding systems were installed especially in the first half of the 20th century together with gas engines, for example in tractors, cars, motorcycles or power plants for the production of power, electricity and / or heat. Besides, e.g. Also ascending carburetor systems in countercurrent and cross-flow carburetor in use.

The "Imbert wood gas plant" or similar devices work in the DC, in particular lumpy wood is fed to the reactor of the gas generator. Special, generic gas generators are for example in the publications DE 198 30 069 A1 . DE 196 43 109 A1 or EP 137 461 A2 disclosed.

The wood is generally thermally decomposed into different components in a first stage. This is done mainly in the reactor in a range of appropriately arranged air nozzles or the like by means of substoichiometric combustion or oxidation, wherein heat is released and temperatures of a few hundred degrees, e.g. about 800 ° C, can be achieved. By rising heat, the wood in the upper part of the reactor is partially pre-dried.

The oxidation zone produces, among other things, coked wood or coal, water and other combustion products that already contain flammable gas components as well as non-combustible gaseous intermediates, such as carbon monoxide (CO) and carbon dioxide (CO ₂ ).

The charred wood or coal generally moves from the oxidation zone down into a reduction zone, thereby reducing some of the combustion products to other combustible gas components. For example, carbon dioxide is oxidized by means of the coal i.a. reduced to additional carbon monoxide, whereby a relatively high proportion of, inter alia, carbon monoxide in the generated combustible gas mixture can be achieved. The combustible gas mixture has as combustible constituents in particular carbon monoxide, hydrogen and methane.

The volume of the wood is greatly reduced in the coking, so that to form a comparatively compact reduction zone, a constriction of the reactor in the transition region of the oxidation zone to the reduction zone is provided. This constriction is often done by means of firebricks, steel elements or the like. The compact reduction zone advantageously allows a reduction of the gas flow and at least partially one Filtration of solid components of the combustion products from the oxidation zone.

From the reduction zone, the combustible gas mixture produced is mainly derived or sucked in to a gas engine, gas storage or the like. With the help of a movable grate coal dust or possibly excess ash is separated from the coal.

In prior art wood gasifiers, gasification may be impaired under certain operating conditions, particularly when using lignocellulosic biomass such as wood from spruce, fir or the like and / or when supplying so-called "false air".

The disadvantage here is that, above all, the quality of the gas mixture produced is reduced and, moreover, tar or tar gas is formed. The relatively hot, gaseous tar optionally condenses on mechanically moving parts, in particular a feed unit for feeding the wood into the reactor, whereby they are covered with tar and a strong impairment of the functioning or a sticking of the corresponding parts arises.

The supply of the wood is generally carried out above the oxidation zone. According to the prior art, the supply unit, with or without lock device, is arranged above the reactor, so that the supply takes place by opening a flap, a slide, a paddle wheel or the like. However, this disadvantageous "false air" is introduced into the reactor, which greatly affects the gasification of the wood.

The so-called "false air" is generally introduced in the feed of wood gasifier. For these reasons, wood gasifiers according to the prior art is a continuous or automatic feeding only partially possible or is a frequent and costly removal of tar on particular fixed parts of the supply unit necessary. If necessary, the corresponding parts must be replaced.

In addition, the use of economically favorable and particularly environmentally friendly residual wood or waste wood, such as. Wood chips, bark, sawdust, sawing by-products or the like, from the woodworking sector and / or forestry severely limited by the possible tar formation.

In addition, due to the comparatively low quality of the gas mixture, the gasifier downstream of the wood gasifier is impaired or destroyed by relatively high tar contents in the gas mixture. The gas engine can be used, for example, for a vehicle to generate heat, i.a. be used by means of a corresponding generator for generating electricity and / or heat and / or the like. For this purpose, the tar content in the wood gas should contain less than about 50 milligrams per cubic meter, as otherwise residues occupy or glue the valves of the gas engine. The result is that they then block and cause the motor to stop. For these reasons, a gas scrubbing with cyclone separators, filters or the like is often connected upstream of the gas engine.

Purpose and advantages of the invention

The object of the invention is in contrast, a device for producing a combustible gas mixture of a carbonaceous starting material, in particular lumpy wood, with a supply unit for supplying the starting material to an oxidation zone of a reactor for the oxidation of the To propose raw material that allows the use of any needle and / or deciduous wood, such as maple, beech, alder, spruce or fir wood, and a continuous or automatic feed while maintaining a high level of operational reliability and high quality ensures combustible gas mixture.

This object is achieved on the basis of a device of the aforementioned type, by the characterizing features of claim 1.

The measures mentioned in the dependent claims advantageous embodiments and developments of the invention are possible.

Accordingly, a device according to the invention is characterized in that the supply unit is arranged in the horizontal direction laterally on the reactor and the supply unit comprises at least one storage device for temporarily storing the starting material.

The storage device can be used as the second storage unit of the device according to the invention in addition to the reactor, which also stores starting material. This measure makes it possible that the supply of the starting material to the device according to the invention can be decoupled advantageous with the supply of the starting material to the reactor. For example, a substantially continuous supply of the starting material to the reactor and an optionally discontinuous, i. only temporarily, in particular relatively short-term supply of the starting material to the device according to the invention can be realized.

The largely continuous supply of the starting material to the reactor allows an advantageous gasification of the starting material or wood, so that high quality Gas mixture can be generated. The discontinuous, in particular comparatively short-term supply of the starting material to the device according to the invention allows a reduction in the amount of "false air" by feeding the device as far as possible. The storage device is advantageously designed to be gas-permeable in the direction of the reactor in general, and to be closed in a gas-impermeable manner to a great extent for charging.

The charging of the device according to the invention is carried out in general as in the prior art by means of one of the pressure and reaction conditions of the reactor largely independent and in particular to the environment not gas-tightly closed or "open" memory or silo, day bunker or the like, i. a third storage device.

In addition, the starting material arranged in the storage device forms a certain barrier, in particular for entering or inflowing "false air", so that it only reaches the reactor with a delay and can not affect the gasification as far as possible.

In addition, an at least partially filled storage device at the same time for optionally generated tar or the like to a certain filtering function. Corresponding tar, u.s.w. is attached, inter alia, to the starting material or lumpy wood or the like, so that the tar advantageously can not interfere with a closure device for opening or largely gas-tight closing of the device according to the invention, in particular movable elements of the same. The tar preferably returns together with the starting material back into the reactor, wherein it can be reacted accordingly.

Especially with the horizontal direction of the side of the reactor arranged supply unit with the storage device, the supply unit or parts thereof may not be affected by tar possibly generated by the fact that the relatively hot tar gases rising in the reactor advantageously condensed on the lid area or the like and possibly dissipated or preferably recycled to the reaction zones for energy recovery , Advantageously, the lid region of the reactor is formed without mechanically movable elements or the like.

For certain measures such as maintenance, repair, conversion or the like, a resealable reactor or a cover element can be provided, which in particular is to be sealed in a largely gastight manner, so that no disadvantageous "false air" can thereby enter the reactor.

Preferably, the tar in the reactor is again supplied to the forming or the reaction zones, so that the energy contained in the tar is recoverable from the device according to the invention. As a result, the overall efficiency of the device according to the invention is substantially increased.

For these reasons, a relatively continuous and / or automatic mode of operation of the device according to the invention can advantageously be implemented with relatively high operational reliability. As a result, a preferred, economical use of the device according to the invention in power plants for the production of electrical energy or in combined heat and power plants, vehicles or the like even under high operational and environmental requirements in appropriate systems possible.

According to the invention, without affecting the operation of the supply unit and / or without relatively frequent or expensive maintenance of the supply unit, a Use of any carbonaceous starting materials, in particular renewable biomass, or any woods allows. For example, needle and / or hardwood as wood chips, sawdust and / or pellet, other renewable resources such as straw and sewage sludge or the like or corresponding mixtures may be used. The use of accumulating waste or residual wood ensures a particularly economically favorable and environmentally friendly operation of the device according to the invention.

In the prior art, the starting material generally falls in free fall on the oxidation zone, whereby a certain compression of the starting material is generated in the region of the oxidation zone. The lateral arrangement of the feed unit according to the invention advantageously causes a lateral introduction of the starting material in the region of the oxidation zone, so that a largely loose stratification of the starting material or of the wood in the reactor is achieved, in particular in the oxidation zone. This ensures an advantageous automatic retraction of the starting material into or from the oxidation zone and, if appropriate, into the reduction zone arranged therebelow, which can effectively prevent a so-called "hollow burning" of the reactor.

In addition, the optionally lateral addition of the starting material leads to a certain movement or rummaging of the starting material in the region of the oxidation zone, whereby the gasification is additionally improved or a "hollow burning" is prevented.

In addition, in particular by the lateral supply of the starting material into the reactor, a thermal insulation layer formed from the starting material can be realized over the particularly hot section of the oxidation zone, whereby advantageously a removal of rising heat can be reduced from the oxidation zone. This ensures above all a favorable oxidation of the starting material.

Advantageously, the storage device is arranged between a feed opening of the reactor and a closure element of the feed unit for opening or largely gas-tight closing of the device. Mainly due to the advantages of the storage device can be dispensed with a closure device on the reactor or a closure of the feed opening of the reactor or the like with this measure. The closure element ensures the supply to the device according to the invention and, moreover, is not to be arranged in the region of hot tar gases, so that if appropriate tar is advantageously condensed or separated before the movable closure element.

For example, the closure element is designed as a rotatable or pivotable flap or the like. Preferably, the closure element is designed as a slide, which ensures, among other things by means of an eccentric element, the almost gas-tight closure of the feed opening of the device according to the invention. This increases the reliability of the device.

In general, according to the invention, an advantageous open and direct feed of the starting material or of the wood into the reactor can be provided. Closure or the like between the reactor and the supply unit can be dispensed with in an advantageous manner. Accordingly, no corresponding, necessary for the closing movable element can be affected or destroyed by possibly formed in the reactor tar in its function. According to the invention, a device without moving elements or components of the feed unit can be realized in the relatively hot region of the device according to the invention, so that Teergas can not affect this. These measures significantly increase the reliability of the device according to the invention.

Furthermore, in a device according to the preamble of claim 1 advantageously at least one level sensor for measuring or determining the degree of filling or the level of the reactor should be provided. The level sensor can be designed, for example, as a partially mechanical, optical, radar, infrared, ultrasonic, sensor and / or the like. Mainly due to the lateral arrangement of the supply unit, a level-mechanically scanning sensor can be realized in a comparatively simple manner.

For example, the sensor comprises an at least partially rotatably mounted and / or deformable baffle element, e.g. a baffle plate, or level flag against which the starting material is moved or transported and / or arranged on the oxidation zone or rests. By the starting material, the sensor element is advantageously cleaned of any deposits or the like, which may lead to the improvement of the reliability of the device.

Advantageously, at least the shaft of the sensor is provided by means of a protective element, e.g. a condensation element or a tar bell or the like, from impairments such as the deposition of contaminate, mechanical damage, etc. protected. Possibly, the rotatably mounted element is arranged on a lever arm or the like. For example, the protective element has an opening, e.g. in the form of a slot in which / the lever arm is arranged.

Due to the change of the level caused Position change and / or angular deflection of the particular rotatably mounted element, the sensor cooperates inter alia with an electrical switching element and an electronic control unit. As a result, when the starting material or wood in the reactor falls below a predetermined threshold value, this may possibly be signaled, a refilling of the reactor, if appropriate by means of a transport, slipping device or the like, initiated or initiated. This is especially advantageous for a virtually automatic mode of operation of the device according to the invention.

Preferably, a control or regulating unit for almost fully automatic control or regulation of the device according to the invention is provided. This allows in particular a controlled and metered supply of the starting material, inter alia in cooperation with the level sensor of the reactor. For example, a largely constant filling level can be regulated in the reactor. Optionally, the air supply to the reactor can be regulated or depending on the fill level of the reactor and / or feed amount of the starting material or the amount of combustible gas mixture produced, u.s.w. adjust. These measures are advantageous for the gasification or the transformations in the reactor, so that high-quality combustible gas mixture can be produced.

Optionally, the supply of the starting material can be carried out almost automatically by sliding or slipping on a sliding element or the like. In an advantageous embodiment of the invention, the supply unit comprises at least one transport device for transporting the starting material from the storage device into the reactor. With this measure, an active, in particular precisely metered or regulated supply of the starting material or wood into the reactor can be realized.

Advantageously, the transport device has an at least partially ascending or sloping transport direction of the starting material in the vertical direction. Preferably, the transport device is formed as in the direction of the reactor rising obliquely, in particular channel or tubular transport device. Especially in these variants of the invention opens an upper end of the transport device in or on the reactor and a lower end or a lower region of the transport device is arranged substantially in the vertical direction below the storage device. As a result, by largely automatically moving the starting material from the storage device, a virtually automatic charging of the transport device and by means of this of the reactor can be realized.

In addition, with these variants, a disadvantageous penetration of relatively hot tar gases into the storage device and further to the mechanically movable and largely gas-tight closing closure element of the device can be additionally prevented by relatively hot gases rising to the upper region of the reactor and thus not by the direction away From the reactor considered sloping or descending transport device flow. In addition, in this case in particular the lumpy wood or the like in the transport device can function as a filter for condensable constituents of the reactor atmosphere.

Advantageously, the storage device has a clearing element for clearing or supplying the starting material to the transport device or to the reactor. This advantageously prevents any relatively bulky wood or the like from getting caught in the storage device or from clogging it, and thus from being able to move on the starting material is interrupted or impaired to the reactor.

The storage device is arranged substantially laterally next to the reactor, so that a comparatively compact device according to the invention with relatively low height can be realized. Optionally, the device according to the invention can be integrated in a structural unit, which is preferably formed with a thermal insulation or the like, whereby an advantageous integration of the thermal energy can take place.

Possibly, the transport device has a section which rises almost vertically and / or both a section rising in the region of the reactor and a section descending in the region of the storage device. Optionally, in the last-mentioned variant, condensed liquids can be discharged in the depression formed in this way, or in the case of a transport device that rises substantially continuously in the direction of transport, in the almost deepest region.

Optionally, the transport device comprises a transport and / or Rüttelband. In an advantageous variant of the invention, the transport device comprises at least one spiral transport element. For example, a so-called worm drive can be provided for the transport device. The sheath of the worm drive is designed in particular as a U-shaped tubular element, so that viewed in the vertical direction above cavities for example, relatively bulky starting materials such as lumpy wood or the like are present. With these measures jamming or the like of the worm drive is largely prevented. Basically, the worm drive or the transport device on a comparatively large game, whereby a sticking or the like can be largely prevented.

Preferably, the lower region of the storage device tapers, so that an advantageous emptying is feasible. In a particular embodiment of the invention, the outlet opening of the storage device is smaller than the cross section of the transport device and / or is adapted to the pitch of the spiral-shaped transport element. Hereby, the regulation of the amount of starting material to be transported is improved, which may, inter alia, lead to an advantageous, possibly to be provided, heat treatment in the area of the transport device. In addition, jamming of the starting material in the region of the outlet opening of the storage device is effectively prevented. It is also conceivable a slider or the like for closing the outlet opening of the storage device, which could additionally reduce the ingress of "false air" during loading. In this case, the storage device would be designed as a lock.

Advantageously, the feed unit comprises a distribution element for substantially uniform distribution of the starting material almost over the entire cross section of the oxidation zone of the reactor. In particular, when using a spiral-shaped transport element, the distribution element is designed, for example, as an element which is tapered in the transport direction and is arranged below the transport element.

In a particular embodiment of the invention, the supply unit has at least one heating device for heating the starting material. This makes it possible for the starting material to be fed to the reactor optionally to be fed to the reactor in a relatively warm and / or dry state. Optionally, can also be relatively humid Starting material or moist wood of the device according to the invention or the storage device are supplied, for example wood with relatively high humidity and / or partially moist sewage sludge or the like. Here, a starting material is provided in which the moisture is such that comparatively little or almost no water is produced in the region of the transport device and / or the storage device.

In principle, all conceivable heating devices can be used, e.g. by means of electrical, chemical energy, in particular by means of combustion, and / or supply of a relatively hot heating medium. As a result, the starting material is advantageously heated or dried in such a way that it is prepared for the subsequent gasification in the reactor.

Advantageously, the heating device has at least one first heat exchanger element for cooling the gas mixture. This advantageously allows heating of the supply unit and, in addition, cooling of the combustible gas mixture. As a result, a gas engine or the like, which is possibly downstream of the device according to the invention, can be provided with a relatively cold gas mixture, in particular without a comparatively large intermediate storage unit, almost immediately. A relatively cold gas mixture advantageously improves the combustion in the gas engine, so that a higher overall efficiency of the entire system can be achieved.

In a preferred variant of the invention, the heating device comprises at least one further, second heat exchanger element with a heating fluid. In principle, the so-called second can understandably also be used without the so-called first heat exchanger element alone as a heating device. With this If appropriate, a particularly relatively high heating of the starting material in the region of the feed unit can be realized in the heat exchanger element, which can additionally improve the gasification in the reactor. As a heating fluid can be used in an advantageous manner exhaust gas of the downstream gas engine or the like. The exhaust gas may possibly have several hundred degrees Celsius. It is conceivable that the starting material is heated to such an extent that it already partially oxidizes in the area of the feed unit, which may possibly have a positive effect on the conversion of the starting material in the reactor. In this variant of the invention, the feed unit or transport device is at least partially designed as a pre-reactor.

Preferably, the heating device is arranged at least in the region of the transport device. As a result, in particular the starting material to be supplied to the reactor in the foreseeable future can be heated with the aid of the heating device, which can lead to an advantageous reduction of heat losses.

In general, the device according to the invention is largely encased with at least one thermal insulation device, so that thermal losses can be largely prevented. This allows an advantageous thermal management of the entire device according to the invention, whereby the gasification of the starting material can be implemented advantageously. In general, the reactor has an operating temperature of about 800 ° C. This ensures both favorable oxidation and reduction in the corresponding zones of the reactor.

Basically, the reduction zone of the reactor to an operating temperature, in addition to a reduction of carbon dioxide and / or the like, especially a reaction of dust generated in the oxidation zone or similar allows. With this measure, in particular the quality of the gas mixture to be generated for the application or combustion in a gas engine is additionally improved.

In addition, by the arrangement of the heating device in the region of the transport device, a relatively large heat transfer surface can be realized in relation to the amount of the starting material to be heated, whereby the heating of the feedstock to be supplied to the reactor can be advantageously realized. Furthermore, this can also be a comparatively long-lasting heating, especially in a relatively long or stretched variant of the transport device, implemented, whereby, for example, the drying of the starting material, in particular of wood, is improved. Relatively long transport devices allow, for example, an advantageous adaptation to spatial conditions of the installation site or the space available for the device according to the invention.

Under certain operating conditions, an adaptation, in particular of the temperature conditions in the feed unit, to the operating conditions of the device according to the invention or in the reactor can be provided, for example. Charging, starting phase, type of wood, reactor and / or air temperature, u.s.w ..

Optionally, one or more cleaning stages or devices between the gas engine and the device according to the invention can be arranged, for example gravitation, inertia such as centrifugal or cyclone or baffle plate, wet scrubber, oil bath, gravel or sand bed, electric , Adsorption filters such as tissue, cork, activated carbon or ceramic filters, catalytically active cleaning elements, etc. Preferably, the cleaning device is formed regenerable. For example, a so-called afterburning of gravel bed filters or the like can take place, so that they can be used further and almost exclusively "white" ash is obtained as waste.

Alternatively or in combination for this purpose, for example, correspondingly contaminated oil of an oil bath filter can be introduced into the storage device of the supply unit, so that, on the one hand, its energy is utilized and, on the other hand, the amount of waste is reduced.

Advantageously, at least two, in particular time-delayed operated cleaning devices or filters are provided. For example, in this case a filter is regenerated, cleaned or burned, while another filter is operated in the filter phase.

In general, for example, a wide variety of sensors can be used in the device according to the invention, in particular in the reactor. Above all, sensors for measuring temperatures, moisture contents, weights, types of starting material, single or multiple gas components, pressures, optical parameters such as permeability, filling levels or levels or the like. These sensors cooperate in particular with a corresponding evaluation and / or control unit for largely automatic operation of the device according to the invention.

In a particular embodiment of the invention, at least one condensation element for accommodating condensable substances or mixtures of substances is arranged in the upper region of the reactor. Preferably, two condensation elements are provided, wherein condensed with a condensation element especially tar gas in a special case of operation as tar and in particular also dissipated or in the reaction zones is returned, for example, in the about 800 ° C hot glow region of the reactor for combustion and / or out of the reactor. In particular, the second condensation element is provided for the condensation of any accumulating steam or the like, so that in particular relatively unpolluted water can be removed from the reactor in an advantageous manner.

Advantageously, an air supply device for supplying air to the oxidation zone at least one heating unit for heating the air to be supplied. As a result, an advantageous preheating of the air to be supplied to the reactor can be realized. This improves the gasification of the starting material or of the wood and additionally increases the quality of the combustible gas mixture.

In general, in addition to the humidity in particular the oxygen in the air for the gasification critical, so that in a specific variant of the invention, almost pure oxygen can be supplied to the reactor. Optionally, a moistening unit for controlling or loading and / or dehumidifying the air to be supplied is provided.

Preferably, the heating unit is designed as a heat exchanger element for heat exchange of the air to be supplied with the reactor. Advantageously, the air supply device is arranged substantially along the circumference of the reactor. With the help of these measures, a far-reaching energy management of the device according to the invention can be realized. In particular, in the gasification of wood, the temperature in the reactor is of crucial importance, so that by means of extensive energy management, a particularly advantageous gasification is possible.

In a preferred variant of the invention, the air supply device is arranged at least in the upper region of the oxidation zone. This ensures that the relatively hot upper region of the reactor, i. in the region of the oxidation zone, for the relatively hot preheating of the air or the like can be used. As a result, the conversion of the starting material is additionally improved, which leads to a particularly high quality of the combustible gas mixture.

Advantageously, the reactor has a smaller diameter and / or cross-section, at least in the area of the feed unit, than in the area of the air feed device. With this measure, jamming or entanglement of the lumpy starting material is effectively prevented at / with the air supply device. Hereby, the risk of hollow fire is additionally prevented.

In addition, this measure makes it possible for the starting material in the area of the air supply device to fill out or fall apart and thus to have more or larger interstices. As a result, the air or the oxygen oxidize the starting material or the wood advantageous.

In principle, at least during the charging phase, air, oxygen, carbon dioxide or the like, in particular by the air supply device by means of a pressure generating unit, e.g. Blower, pump, etc., are introduced into the reactor. In this case, a pressure equalization is preferably realized in the reactor, so that the "false air supply" and thus the risk of hollow fire is further reduced.

Preferably, in an apparatus according to the preamble of claim 1 is an at least partially movable Grate element for removing coal dust, ash and / or the like provided from the reactor. By means of this measure, pulverized coal and / or optionally occurring ash can be separated and / or removed from the coal or the reduction zone. In general, the grate element has openings such as slots or the like.

Advantageously, the grate element has at least one section sloping towards the edge region in the vertical direction. This measure essentially avoids the accumulation of material in the central region of the grate element by the shaking. In addition, this allows separation of the pulverized coal, ash or the like from the reduction zone, in particular towards the jacket region of the lower section of the reactor, so that the ash or the like can be carried out comparatively easily from the reactor manually and / or largely automatically.

In a particular embodiment of the invention, the grate element is designed as a collecting element, in particular filter element or sieve or the like, for retaining the intermediate product. Preferably, the collecting element is designed such that it largely closes the reactor downwards and / or laterally. For example, the grate element is arranged as a virtually closed element or cage, basket or the like around the lower region of the reactor or of the reduction zone. As a result, almost no intermediate product or coal can escape from the reactor and, in addition, ash or the like can be removed from the reactor. Preferably, the ash or the like is sucked out of the reactor area, in particular by means of the gas mixture or gas engine.

Advantageously, a gas mixture removal opening is arranged in the lower region or at the bottom of the reactor, so that resulting ash or the like advantageously from the reactor is removable. By this measure, a largely automatic removal of accumulating ash or the like is realized in particular, so that the automatic operation of the device according to the invention is further improved.

Preferably, the grate element surface enlarging areas, structures or elements, so that inter alia, the gas flowing through the reactor has a relatively long residence time or reaction time in this and thus the generation of the combustible gas mixture is improved.

Furthermore, with this measure, the gas resistance is reduced, which in particular increases the degree of engine filling and thus the gas engine is advantageous to operate.

In an advantageous embodiment of the invention, the grate element is height-adjustable or adjustable in the longitudinal direction of the reactor. As a result, in particular the amount of material or the volume of the reduction zone and / or the residence time of the reaction gas in the reduction zone can be changed or regulated. Possibly foreign material collects like stones, etc. in the reactor, so that by means of the aforementioned measure, the volume or the amount of the intermediate product in the reduction zone is adjustable. This additionally improves the production of the combustible gas mixture.

In addition, removal of the foreign material from the reactor can be realized comparatively easily with a correspondingly formed grate element.

In principle, in particular when using lumpy needle and / or deciduous wood such as wood chips or the like, with the aid of the device according to the invention, a reactor realized an approximately constant level, a largely constant amount of coal in the reduction zone, a glowing, relatively hot, for example, about 800 ° C hot coal in the reduction zone, almost no waste, except possibly relatively small amounts of coal dust in the Generally, no so-called hollow burning or burning through and, above all, as far as possible has no tar or tarry gas. The pulverized coal is fed back to the oxidation zone in an advantageous manner, so that a largely waste-free operation of the device according to the invention is possible.

At the same time a relatively frequent cleaning or removal of tar on the closure element is not necessary, since this is located in the cold area of the device or is not affected by tar. In addition, an automatic loading of the device according to the invention can be provided. Generally, you can also load manually.

embodiment

An embodiment of the invention is illustrated in the drawing and will be explained in more detail with reference to FIGS.

Figur 1

eine schematische Darstellung einer Vorrichtung gemäß der Erfindung,

Figur 2

einen schematischen Ausschnitt einer weiteren Vorrichtung gemäß der Erfindung,

Figur 3

ein schematisches Detail einer Zufuhr des Ausgangsstoffes und

Figur 4

ein schematisches Detail einer Speichervorrichtung.

In detail shows:

FIG. 1

a schematic representation of a device according to the invention,

FIG. 2

a schematic section of another device according to the invention,

FIG. 3

a schematic detail of a feed of the starting material and

FIG. 4

a schematic detail of a memory device.

In FIG. 1 is a reactor 1, a supply unit 2 and only a section of a storage silo 3 shown.

As a starting material, for example, wood chips from waste or residual wood stored in the storage silo 3 are not shown in detail. The storage silo 3 comprises a storage volume many times greater than a volume of a storage device 4 of the supply unit 2. The comparatively large volume of the silo 3 allows a stocking of wood chips for a relatively long operating time of the device according to the invention, such. one or more weeks or months.

Preferably, the wood in the silo 3 by means of heat, in particular waste heat from the reactor 1, pre-dried. The silo 3 is optionally formed as a top open silo 3, storage space with a loading device for feeding the device according to the invention or the like. The storage device 4 has, for example, a volume which is sufficient to operate the reactor 1 for about several hours or about one day without opening an almost gas-tightly closed flap 6 or without feed from the silo 3. The gas-tight closing of the storage device 4 may alternatively be realized by means of a slider or the like.

The wood chips are fed by means of a screw feed 5 of the device according to the invention. For loading the largely gas-tight closing flap 6 is opened. The loading phase can take several minutes take, in particular until the storage device 4 is largely filled and the flap 6 is close to almost gas-tight again.

A level sensor 22 may detect the level of the storage device 4, e.g. a rotary wing, ultrasonic or the like. Preferably, the flap 6 is hydraulically, pneumatically, mechanically and / or electrically operated, wherein a largely automated controllable and operable flap 6 is advantageous.

The chips are transported by means of a worm drive 7 from the storage device 4 in the reactor 1 and fed. Advantageously, an electric motor 8 is provided for this purpose.

The worm drive 7 is arranged in a manner not shown, both a heat exchanger for cooling the combustible gas mixture produced as well as a heat exchanger for heat recovery of the heat contained in an exhaust gas stream of not shown gas engine. The two heat exchangers are preferably arranged as half-shell-like elements arranged around the worm drive and / or as tube elements around the worm drive 7. In this case, inter alia, a multi-stage heating of the chips in the area of the worm drive 7 with different temperature levels can be realized.

The combustible gas mixture generated by the reactor 1 is discharged from the reactor 1 by means of a gas connection 9 to a gas engine, not shown, wherein the gas mixture is generally previously cleaned by means of a cyclone, filter and mixed with air by means of an air mixer. Optionally, the worm drive 7 additionally a have electrical heating of the screw element. Already in the area of the worm drive 7, the chips are partially pre-dried and preheated under certain operating conditions.

The reactor 1 comprises, in particular, an oxidation zone 10 and a reduction zone 11, wherein a firebrick wall 12 is provided as a constriction 12 in the transition region of the two zones 10 and 11. In general, glowing or oxidizing wood chips 10 are generally provided above the firelight brick wall 12 in the case of substoichiometric combustion and, to a great extent, below the constriction, glowing coal 11 according to the invention during operation of the reactor 1. On the glowing chips is about 10 to 20 cm thick, the glowing chips largely covering, not glowing woodchip layer formed, in particular the glow zone 10 is thermally insulated and at the same time provided as a drying zone or warming up zone for the chips.

To determine the filling level of the wood chips, the reactor 1 has a level indicator 15, which according to FIG. 1 or 2 is shown folded up. This can detect the filling level of the reactor 1 as a mechanical sensor 15 and actuate an electrical switching element at a predetermined filling level, so that woodchips are fed to the reactor 1 by means of the worm drive 7. Here, both a phase-wise and almost continuous feeding of wood chips can be realized.

The supply of oxygen into the reactor or to the oxidation zone 10 takes place in particular by means of several, eg, about five air nozzles 16. The use of individual air nozzles 16 has the advantage that the air flowing through them is to be used for advantageous cooling of the air nozzles 16, whereby an optionally complex cooling of the nozzles 16 and / or relatively low heat resistant materials for the air nozzles 16 can be provided.

The air to be supplied to the reactor 1 flows through a heat exchanger 18, which is preferably arranged substantially completely in the jacket region of the reactor 1 in the region of the relatively hot oxidation zone 10 and / or in the circumferential direction. The air supply also includes an advantageous air ring 17, which allows a nearly uniform or uniformly heated supply of air by means of all radially arranged air nozzles 16 to the oxidation zone 10. The heat exchanger 18 is additionally preheated by the outflowing gas mixture. These measures lead to an advantageous gasification in the reactor 1. In FIG. 2 no heat exchanger 18 is provided.

For igniting or burning the wood chips in the reactor 1, a largely gas-tight sealable ignition hole 13 is provided. Especially for supplying the outside air to the air rings 17 and 18, the reactor 1, a so-called sniffer flap 14.

A condensation element 24 allows tar to condense and a condensation element 23 allows condensing of water in the upper region of the reactor 1, so that an advantageous separation of tar and water takes place and the tar is recycled in a manner not shown in the reaction zones 10 and 11 respectively can be. The water is preferably removed from the reactor 1.

With the aid of a Rüttelrostes 19 coal dust and any resulting ash can be separated from the coal of the reduction zone 11 and forwarded to an ash box 20 or the like. The Rüttelrost 19 can be moved by means of a vibrator 21 for this purpose.

In FIG. 2 a section of another device according to the invention is shown. In particular, the reactor 1 has a sensor 15 designed as a baffle plate 15 or level flag 15.

The reactor 1 according to FIG. 2 also shows in the area of the feed unit 2 a smaller diameter than in the area of the air nozzles 16, so that lumpy wood or the like introduced can not get caught and that this is loose, with relatively large gaps in the oxidation zone 10. As a result, the oxidation of the starting material is improved or a hollow burning of the reactor 1 is avoided.

Furthermore, designed as a grate basket 19 grate element 19 is provided. The grate basket 19 encloses the Schamottmauerung 12 almost completely, so that in general no coal enters the ash pan 20. With the aid of an ash plate 22 and arranged below the reduction zone 11 gas port 9, the resulting ash is removed from the reactor 1 and then separated by means of a filter from the gas mixture. This eliminates an opening of the reactor 1 to remove the ash, so that penetration of "false air" is effectively counteracted.

In addition, the Rüttelrost 19 in the central region of the axis of rotation on a survey 24, so that accumulation of material is prevented by the rotation or shaking in the region of the axis of rotation.

In FIG. 3 the feed of the starting material is shown in more detail in plan view. Here, the shape of a bottom plate 25 of the screw feed 2 over the oxidation zone 10 becomes clear. Due to the advantageous shape of the bottom plate 25, for example, wood chips can be fed to the reactor 1 with / without sawdust, with a largely uniform distribution of wood chips with / without Sawdust is achieved. This in turn improves the oxidation conditions in the reactor 1.

In general, the reactor 1 can have both a round, elliptical, rectangular, star-shaped or similar or a ribs or branches or the like having cross section, in particular in the region of the air nozzles 16. In this way, a comparatively high-performance or large-scale reactor 1 can be realized, without any disadvantageous oxidation taking place.

FIG. 4 shows in plan view the lower portion of the storage device 4 with a reamer 25 and an outlet opening 26. By the reamer 25 and compared to the diameter of the screw conveyor 7 smaller opening 26, which is also adapted to the screw pitch, an advantageous regulation of the reactor to the first transported amount of chips can be realized, which among other things improves the predrying of the starting material in the transport device 7.

Furthermore, jamming of wood chips in the region of the opening 26 is effectively prevented. A closure element is conceivable for closing the opening 26 during the charging of the storage device 4.

In general, the device according to the invention can be largely realized with relatively ordinary steel or the like, which in addition to a comparatively good thermal conductivity of the material used, which has an advantageous effect on the gasification, an economically favorable production is possible.

Basically, the device according to the invention for fuel production for a gas engine, in particular a Vehicle, combined heat and power, electrical power generation, or the like can be used. For this purpose, in particular a corresponding system with a device according to the invention is to be provided together with a gas engine and optionally an electric generator.

In general, the reactor may have two or more feed units. This allows a separate supply of various starting materials such as sawdust, wood chips, straw, sewage sludge or the like to the reactor, whereby an advantageous mixing of the starting materials in the reactor can be realized. A possible disadvantageous separation of the starting materials can be prevented in this way. Alternatively or in combination with this, a feed of various starting materials into a single feed device or storage device can also be realized.

Moreover, the apparatus according to the invention can be used for fuel production of a fuel cell, i. According to the invention, the generator or the internal combustion engine is designed as a fuel cell. For example, in this case, the hydrogen, methane or the like of the fuel gas or wood gas can be provided in corresponding fuel cells for generating electrical energy.

In general, several or numerous devices according to the invention can be modularly coupled and operated in particular for the realization of comparatively powerful or large units. If appropriate, one or more gas engines and / or electric generators can be provided here. If one module fails, another module can advantageously at least partially compensate for the failure.

Claims (16)

1. Device for producing a combustible gas mixture from a carbon-containing starting material, in particular from pieces of wood, said device comprising a supply unit (2) for supplying the starting material to a reactor (1), wherein the reactor (1) comprises at least one oxidation zone (10) for the oxidation of the starting material and a reduction zone (11) for reducing at least one intermediate product of the oxidation and the supply unit (2) is arranged in horizontal direction laterally on the reactor (1), characterised in that the supply unit (2) comprises at least one storage device (4) for the intermediate storage of the starting material and at least one filling level sensor (15) is provided for measuring the filling amount or the fill level of the reactor (1).
2. Device according to claim 1, characterised in that the storage device (4) is arranged between a supply opening of the reactor (1) and a fastening element (6) of the supply unit (2) for opening or closing the device.
3. Device according to one of the preceding claims, characterised in that the filling level sensor (15) is designed at least partly as a mechanically scanning filling level sensor (15).
4. Device according to one of the preceding claims, characterised in that the supply unit (2) comprises at least one transport device (7) for transporting the starting material from the storage device (4) into the reactor (1).
5. Device according to one of the preceding claims, characterised in that the transport device (7) has a direction of transport of the starting material ascending at least partly in vertical direction.
6. Device according to one of the preceding claims, characterised in that the supply unit (2) comprises at least one heating device for heating the starting material.
7. Device according to one of the preceding claims, characterised in that the heating device is arranged at least in the region of the transport device (7).
8. Device according to one of the preceding claims, characterised in that an air supply device (16, 17, 18) is arranged substantially along the reactor circumference.
9. Device according to one of the preceding claims, characterised in that the reactor (1) has, at least in the region of the supply unit (2), a smaller diameter and/or cross section than in the region of the air supply device (16, 17, 18).
10. Device according to one of the preceding claims, characterised in that an at least partly movable grate element (19) is provided for removing carbon dust and/or ash from the reactor (1).
11. Device according to one of the preceding claims, characterised in that the grate element (19) comprises at least one section falling in vertical direction towards the edge area.
12. Device according to one of the preceding claims, characterised in that the grate element (19) is designed as a collecting element for holding back the intermediate product.
13. Device according to one of the preceding claims, characterised in that the grate element (19) is designed to be adjustable in longitudinal direction of the reactor (1).
14. Installation for producing electrical power and/or thermal power by means of a device for producing a combustible gas mixture from at least one carbon-containing starting material, a combustion machine for combusting the gas mixture and/or a generator for generating electrical power, characterised in that the device is designed according to one of the preceding claims.
15. Method for generating a combustible gas mixture from at least one carbon-containing starting material with a device for producing the combustible gas mixture from the carbon-containing starting material, characterised in that the device according to one of the preceding claims is used.
16. Method for generating electrical power and/or thermal power with an installation for producing electrical power and/or thermal power, characterised in that the installation according to claim 15 is used.

Images