WO2013060474A1

WO2013060474A1 - Method for operating a gasification reactor

Info

Publication number: WO2013060474A1
Application number: PCT/EP2012/004503
Authority: WO
Inventors: Martin ZUCKERMAIER; Thomas Tschaftary
Original assignee: Ligento green power GmbH
Priority date: 2011-10-28
Filing date: 2012-10-26
Publication date: 2013-05-02
Also published as: EP2771437A1; DE102011117140A1

Abstract

The aim of a method for operating a gasification reactor (1) that comprises a reaction chamber (4) for the autothermic and/or allothermic gasification of carbonaceous combustible material into useful gases is to improve the efficiency of a gasification reactor for gasifying carbonaceous combustible material into useful gases with respect to useful gas yield and thermal yield as well as to the operational stability of the gasification reactor. To this end, the composition, quantity, pressure, speed, temperature and/or specific discharge pulse of a gasification agent that is fed via control inlets (10) of the reaction chamber (4) are controlled in a variable manner by means of a number of controlled variables that are detected in the reaction chamber (4), the composition (34) of the useful gas and/or the volume flow (30) of the useful gas and/or the respective pressure (36) in a reservoir (3) for the combustible material, in the reaction chamber (4) and/or in a gas outlet (8) being used as a controlled variable (30, 32, 34, 36, 38, 40).

Description

description

Method for operating a gasification reactor

The invention relates to a method for operating a gasification reactor (1) with a reaction chamber (4) for the autothermal and / or allothermal gasification of carbonaceous fuel to useful gases, wherein composition (28), amount (20), pressure (22), speed, Temperature (26) and / or specific outlet pulse of a control inputs (10) of the reaction chamber (4) added gasification variable based on a number of in the reaction chamber (4) determined control variables (30, 32, 34, 36, 38, 40) to be controlled. Such a method is known, for example, from DE 10 2004 020 919 A1.

definitions

In the present invention, a reactor is generally understood to mean a part of a plant in which chemical reactions of one or more starting materials to one or more products are carried out. Therefore, in this invention, under a gasification reactor, a container is understood to be a part of an installation in which carbonaceous fuel material is converted into useful gases, ie gasified.

In the present invention, a useful gas is understood as meaning a substance or a substance mixture which is suitable both itself as fuel for internal combustion engines and also as raw material for further chemical production processes.

In the present invention, a carbonaceous fuel material is understood to mean such a material whose carbon contained in the form of an exothermic reaction oxidizes to carbon dioxide (CO ₂ ) in air, that is to say it can be burned. In this sense, the carbonaceous fuel includes in particular

CONFIRMATION COPY in particular biomass, fossil fuels and synthetic organic substances, especially according to carbon-containing plastics. In the present invention, biomass is generally understood to mean any carbonaceous substance which is derived directly or indirectly from physiological processes of living organisms, in particular from plant photosynthesis, is not deprived of the natural carbon cycle and can also be exothermally converted to CO2 by organisms. Examples of biomass are fermentation residues, wood, leaves, hay, straw, paper, cardboard, compost, faeces and sewage sludge.

In the present invention, fossil fuels are understood to mean those forms of biomass which are located in a geological depression and are thus removed from the natural carbon cycle. Examples of fossil fuels are asphalt, tar, bitumen, peat, lignite, hard coal and graphite.

A carbonaceous fuel material may also be understood to mean a mixture of different carbonaceous fuel materials, for example biomass, synthetic-organic materials and especially plastics. Another example of a carbonaceous fuel is therefore household waste as a mixture of such fuels. Thus, the shape of the carbonaceous fuel is independent of its shape, another example is wood in the form of logs, wood chips of varying size, sawdust or in the form of pellets.

Technical background

The pyrolysis as a purely thermal decomposition of biomass, hard coal and lignite runs predominantly endothermic depending on the oxygen content and the binding of the oxygen. Within the fuel, the pyrolysis may also be exothermic. In particular, in the pyrolysis of hard coal or brown coal arise in addition to carbon monoxide (CO), hydrogen (H ₂ ) and methane (CH ₄ ), for example, still volatile hydrocarbons. Plastics, for example, consisting only of carbon and hydrogen, pyrolyze under exclusion of air exclusively to lower hydrocarbons. Carbon monoxide (CO), hydrogen (H ₂ ) and methane (CH ₄ ) and volatile hydrocarbons are flammable, are ideal as fuels for internal combustion engines, are important starting materials for many chemical manufacturing processes and are therefore valuable Nutzgase. Methane (CH ₄ ) and pure carbon, for example in the form of mineral graphite or synthetic coke, are not or no longer pyrolysable.

However, carbon-containing fuel materials can be converted to useful gases with gasification agents, for example carbon with a deficiency of O ₂ to CO, then carbon with water (H ₂ O) to CO and H ₂ , then CH ₄ with O ₂ to CO. However, the gasification reactions of carbonaceous fuel with H ₂ O are endothermic. As a natural gasification agent is used in particular air, which may also be enriched with H ₂ O, for example as an aerosol or vapor. In the present invention, therefore, a gasification agent is understood to mean a pure substance or substance mixture whose addition to the carbonaceous fuel material increases the conversion into useful gases.

The gasification of carbonaceous fuel to Nutzgas is predominantly economical only if the fuel is not only readily available or cheap, but the gasification in their energy balance depends solely on the energy content of the fuel. This relates in particular to the use of the useful gas as actual fuel for internal combustion engines, for example for the operation of a gas engine or a gas turbine. The gasification of carbonaceous fuel to Nutzgas then requires a total exothermic running overall process, the energetic itself as long as enough fuel is available. In addition, the heat released can also be used, for example, for heating residential buildings, as is the case with combined heat and power in combined heat and power plants (CHP). In a CHP, an internal combustion engine is in turn coupled to a generator, which then finally converts mechanical energy into electrical energy. The combustion of carbonaceous fuel with O ₂ to CO, however, is so weakly exothermic that the energy released is not sufficient to sustain simultaneously ongoing pyrolysis and / or gasification reactions with H ₂ O permanently. The energy required for the entire gasification process must therefore be applied by the highly exothermic combustion reaction of carbonaceous fuel with O ₂ to CO ₂ . The highest possible efficiency in terms of Nutzgas- and heat yield of such an autothermal gasification is achieved at an optimum, in which the extent of combustion to CO ₂ just sufficient to provide the necessary energy contribution for pyrolysis and gasification reactions. This optimum in terms of incomplete combustion depends on the composition and nature of the fuel, the supply or optimal metering of the gasification agent, the nature and isolation of the gasification reactor and thus summarized by the entire reaction. Here, the change in the fuel during the entire gasification process is also taken into account or not negligible.

In the classic fixed bed gasification reactor, wood is a carbonaceous fuel, like a normal grate on a grid. As a countercurrent process, air is sucked through the grate and the burning wood as a gasifying agent. The upper layers of wood burn only partially and pyrolyze at the same time to Nutzgas, which is sucked off at the upper end of the furnace. Air and natural gas move countercurrently in the opposite direction to the slowly sinking wood. The resulting useful gas has a relatively low temperature of about 100 ° C and contains due to the ongoing drying and pyrolysis of the wood correspondingly much water vapor and organic constituents, which condense on further cooling to an acidic wood tar.

In the DC process for wood gasification, air as a gasifying agent directly above the grid directly into the hot gasification reaction zone of the Fed fixed bed gasification reactor and vacuumed under the grate. The internal reactor gas and the useful gas and air move in the same direction in the area of the grid, ie in direct current. The temperature of the reactor internal gas or useful gas is much higher here than in the countercurrent process. The useful gas as the end product from the reactor internal gas contains significantly less wood tar, the wood tar resulting from the DC process having a basic pH.

The wood tar produced in the countercurrent and DC wood gasification processes is not suitable for internal combustion engines, but damages them due to its adhesive properties. Also in the gasification of other carbonaceous fuels, similar high-viscosity residues occur, which are generally referred to as condensate in the present invention. The resulting condensate not only reduces the efficiency with respect to material utilization balance of the gasification reactor, but must be removed from the useful gas by a gas scrubber. This additionally reduces the energy balance of the entire system and additionally requires washing liquid, for example water. Since the condensate is not only corrosive due to its pH, but also toxic and difficult to biodegrade, this results in a disposal problem. In US 2010/0107494 A1 a fixed-bed gasifier for biomass is proposed with a successive fuel supply, which promises a higher efficiency in terms of fuel turnover, but does not eliminate the formation of condensate or the resulting condensate can not continue to use in the gasification process.

One approach to the gasification of carbonaceous solid fuels is to use fluidized bed gasification reactors in which the fuel is converted into useful gases in an incomplete fluidized bed furnace. In this case, no condensate is generated, since this is also converted to Nutzgasen. However, gasification in fluidized-bed gasification reactors is restricted to solid fuel materials having a particle size of less than 40 mm with a water content of at least 25% by weight, the particles being suspended by a fluid medium that constantly swirls, for example air. have to. To maintain the fluidized bed, therefore, an external fluid supply with a high flow rate is necessary, which corresponds to an externally supplied work. Furthermore, fluidized-bed gasification reactors can not be operated autothermally, but only allothermally, ie with the supply of external heat energy. The total supply of these two types of energy shall be deducted from the total efficiency of the installation. This gasification technology is only economical for power plants in the power range of 1, 5 to 3 MW, whereby the overall efficiency is only about 30%.

A special form of the fluidized-bed gasification reactor is the Winkler generator, in which the fluidized bed can be maintained even better in the entire reactor space by means of ring loops arranged in series around the reactor body. Advantages of the Winkler generator are a homogeneous temperature distribution and better mixing of the particles compared to other fluidized bed gasification reactors. However, the Winkler reactor is only suitable for the gasification of coal, especially lignite, limited to the smallest possible particle size.

A significant improvement of the fluidized bed gasification reactor is provided by the entrained flow gasification reactor in which the carbonaceous

Fuel is introduced as dust, slurry or paste as a burner in the gasification room. Here, the gasification processes take place in a cloud of dust. This form of supply requires a corresponding pretreatment of the fuel, especially in biomass as a fuel to be introduced via a pneumatic system in the carburetor and gasified there in a very short time. Even such systems can be operated only with supply of work and heat energy. Here, the supply of heat energy by a continuous ignition with a Zündfackel.

The Koppers-Trotzek reactor as a special form of entrained flow gasification reactor is particularly suitable for the gasification of finely ground coal to useful gas. The coal dust is fed in laterally at high speed, so that only a single ignition is needed and the gasification process otherwise autothermal can be performed. However, operation of the Koppers-Trotzek reactor still requires the supply of work to maintain the flow of air.

Both in the various embodiments of the fluidized bed gasification reactor and those of the entrained flow gasification reactor, the gasification processes can not be maintained solely by the supply of fuel. In all versions of these reactor types, the overall efficiency is limited to a maximum of 30 to 40% by the necessary supply of work to maintain the vortex or flight flow. According to the prior art fixed-bed gasification reactors with cocurrent or countercurrent principle, fluidized bed and entrained flow gasification reactors are limited to the specific nature of the carbonaceous fuel material, in principle, a pretreatment of the respective carbonaceous fuel material is required. Necessary pretreatments of the fuel material also considerably limit the cost-effectiveness of gasification plants, in particular CHP plants. Although in fixed-bed gasification reactors compared to the fluidized bed and entrained-flow gasification reactors the supply of external work is limited only to that of the carbonaceous fuel and the gasifier, maintaining optimal conditions for the pyrolysis as well as gasification reactions is generally more difficult. In fixed bed gasification reactors with a DC or countercurrent principle, the definition of a given fuel quality and piece size, for example, to so-called G50 wood chips, particularly disadvantageous. Deviations from this, especially in terms of piece quality, water content and dust content, cause varying pressure and temperature conditions. Such deviations then require, for example, an excessive supply of air as a gasification agent. This leads to a strong dilution of the Nutzgas by atmospheric nitrogen and water vapor and an increased formation of entrained condensate. Quality and yield of the useful gas are then reduced so much that a costly gas scrubbing must be carried out prior to its utilization. Increased formation of condensate not only significantly lowers the overall efficiency of the plant, but also leads to blockages in the reactor, which can lead to complete failure of the entire plant. To- In addition, the purification of fixed-bed gasification reactors from condensate is very expensive.

Task and solution

The invention has for its object to improve the efficiency of a gasification reactor for the gasification of carbonaceous fuel to Nutzgasen with respect to Nutzgas- and heat yield and its operational stability by a corresponding operating method. This object is achieved by the combination of features of claim 1 in an inventive manner The back-related claims include some advantageous and partially for themselves inventive developments of the invention.

The invention is based on a gasification reactor with a reaction chamber for the gasification of carbonaceous fuel by adding gasification agents to Nutzgasen. In the reaction chamber is the carbonaceous fuel. In the case of solid fuel materials, a continuous supply can take place via a reservoir connected to the reaction chamber. The conversion to the Nutzgasen as the sum of all individual pyrolysis and gasification reactions therefore takes place predominantly in the reaction chamber. The gasification reactor according to the invention can also be designed completely as a reaction chamber.

As an essential feature of the invention, composition, amount, pressure, velocity, temperature and / or specific exit pulse of a gasification agent added via control inputs of the reaction chamber are variably controlled according to claim 1 by means of a number of controlled variables determined in the reaction chamber. As a result, a variable adjustment of the operation of the respective present states in the reactor is possible and it can be done an optimized gasification of the fuel. Another important feature is the composition, in particular the calorific value of the useful gas used as a controlled variable. This is essentially influenced by the proportion of the water fed to the reaction chamber. By reduction of hydrogen and carbon monoxide are generated from water and carbon, which have a high calorific value. For example, if the calorific value of the useful gas is too low, the supply of water vapor in the gasification agent can be increased.

In an alternative or additional embodiment, the volume flow of the Nutzgases is used as a control variable. This is also influenced by the proportion of the water fed to the reaction chamber, but in addition also by the total amount of the supplied gasification agent. A higher amount of gasification agent increases namely the gas volume in the reaction chamber and thus also the volume flow at the outlet.

In a further alternative or additional embodiment, the respective pressure in a reservoir for the fuel, in the reaction chamber and / or in a gas outlet is used as a controlled variable. For example, the pressure in the reaction chamber is influenced essentially by the total amount of the gasification agent supplied, but also by the respective distribution of the gasification agent via the various control inputs.

Advantageously, the reaction chamber in this case has a plurality of control inputs and composition, amount, pressure, speed, temperature and / or specific exit pulse of the added via the respective control input gasification agent will be controlled at least partially independently of the other control inputs. Consequently, during operation of the gasification reactor, several, ideally every position within the reaction chamber are accessible through these control inputs. Each individual control input thus defines a reaction zone, all reaction zones thereby forming the reaction space which completely fills the reaction chamber. Since the control inputs are at least partially controlled independently of one another, in each reaction zone of the reaction space, the addition of gasification agent with respect to its composition, speed, temperature, pressure and amount as well as with respect to the specific exit pulse is variable over time.

In terms of design, this can be realized in that the side walls of the reaction chamber are interspersed with a multiplicity of such control inputs or that a holder with a plurality of recessed control inputs projects into the reaction chamber. Depending on the predominant nature of the carbonaceous fuel material in interaction with the geometry of the reaction chamber, in particular if the diameter of the reaction chamber is greater than its height, the combination of both constructive possibilities for the arrangement of the control inputs proves to be advantageous, whereby the accessibility of the entire reaction space is.

Throughout the gasification process, the nature of the fuel material changes. In particular, in the gasification of solid, carbonaceous fuel materials in a DC fixed-bed gasification reactor constructed according to the invention, a coking gradient which decreases vertically from the lower to the upper part of the reaction chamber is formed during the progress of the gasification process. Therefore, in the progressing gasification process in the lower reaction zones for gasification of the resulting pure carbon increased water vapor is supplied together with the hot reactor internal gas. In this case, C0 ₂ can be regarded as a gasification agent itself from 600 ° C itself, since then its equilibrium reaction with carbon according to Boudouard to 23% on the side of CO. In summary, therefore, the gasification means comprise at least one of the components O ₂ or H ₂ O, the gasification agent CO ₂ being generated during the gasification process itself.

Since the gasification process of solid, carbonaceous fuel materials in accordance with the invention carried out DC fixed bed gasification reactors a predominantly vertical reaction gradient is determined, a structural simplification is possible. This constructive simplification is that the control inputs are thus combined horizontally into two-dimensional, but independent, reaction zones by being connected horizontally by ring lines, which in turn circulate the gasification reactor or the reaction chamber. Here, in turn, in each planar reaction zone of the reaction chamber, the addition of gasification agent or the return of the reactor internal gas with respect to composition, temperature and pressure and thus quantity variable over time.

In a further advantageous embodiment of the method, in addition, the amount of the carbonaceous fuel material supplied to the reaction chamber is also variably controlled on the basis of a number of controlled variables determined in the gasification reactor. This allows a further influencing of the parameters within the reaction chamber by externally controllable variables.

Advantageously, a temperature in the reaction chamber is used as a controlled variable. Here, as shown above, advantageously also a plurality of temperatures in different areas, eg the reaction zones described can be used. In this case, composition, amount, pressure, speed, temperature and / or specific exit pulse of the gasification agent added via the respective control input are advantageously controlled by means of the temperature in the reaction chamber at the respective control input as a control variable. In each reaction zone, the respective temperature substantially influences the type of reactions which occur in the respective zone. Higher temperatures, for example, allow the combustion of carbon residues, while comparatively lower temperatures improve the formation of useful gases. The temperature in the respective reaction zone can be influenced by the admission pressure, temperature and the proportion of the water vapor of the gasification agent supplied at the respective control input. If the pressure and temperature of the gasification agent supplied increase, the temperature in this area also increases, while the increase in the means a reduction in the temperature by heat energy consuming reduction operations.

In particular, the pressure difference should be used as a control variable via a gas-permeable retention device between the reaction chamber and an ash box of the gasification reactor in an advantageous embodiment. An increase in the pressure difference here indicates a blockage of the retention device with carbon residues. These carbon residues arise in particular at comparatively low temperatures, which in turn are generated by a high water vapor content in the gasification agent. An increase in the pressure difference should therefore be counteracted here by reducing the water vapor content.

In a further advantageous embodiment, the composition, moisture, lumpiness and / or dust content of the fuel are used as controlled variables. By recording these parameters, the respective parameters within the reaction chamber can be optimally adapted to the fuel used. Thus, such operated gasification reactor is suitable for a variety of different fuel materials.

In summary, the inventive method allows an optimal and accelerated reaction of the gasification process with respect to Nutzgasausbeute in its entire time through the regulated, locally varied and the history adapted supply of gasification agent. Even with the use of solid, carbonaceous fuel materials, such as biomass, the formation of condensate is avoided, since the residence time of the hydrocarbons can be made as long as possible by regulating the process, so that the cracking of hydrocarbons (tars) in as small as possible Pieces can be done. Furthermore, the regulation of the process ensures that the temperatures in the flowed through spatial areas are uniformly high so that the cracking reaction of the condensate takes place as quickly as possible. The temporally and locally individually metered addition of gasification in the invention underlying gasification reactor replaces the Winkler generator necessary, extremely energy-consuming preservation of the fluidized bed for optimal and condensate-free gasification of the fuels. Furthermore, a gasification reactor operated according to the invention does not require continuous ignition of the fuel material operated with it, for example by means of an ignition flare.

The process according to the invention combines the advantages of fluidized-bed and air-current gasification reactors with those of fixed-bed gasification reactors, whereby only a fraction of external work for supplying the gasification agent and recycling the internal reactor gas must be supplied in comparison to maintaining a fluidized bed or a flow stream. For this external work, a fraction of the generated useful gas is sufficient. The useful gas generated by the method according to the invention can be supplied to an internal combustion engine, which in turn is coupled to a generator. The work necessary to control the reactor is then provided by a fraction of the electrical energy converted by the generator. Thus, the performance of the inventively operated reactor depends solely on the chemical energy content of the carbonaceous fuel. Overall, the method provides a stable and completely autothermal operation of the gasification reactor according to the invention with a high overall efficiency, in particular as a subsystem of a CHP.

Finally, the method according to the invention is particularly advantageous over all embodiments of vortex and entrained flow gasification reactors in that each type and form of carbonaceous fuel material can be used in any state of aggregation for gasification. For example, a DC fixed bed reactor designed according to the invention may additionally have a gas feed device in the reaction chamber. Also plastic waste and household waste as an example of extremely inhomogeneous mixtures of carbonaceous fuel materials can be gasified with a high overall efficiency in a DC fixed bed reactor according to the invention. During the operation of the gasification reactor operated according to the invention, the variation of process characteristics is possible. First, it is possible to vary the number of reaction zones. The initially independent control inputs may be controlled to form either a single total reaction zone or a plurality of arbitrarily partitionable partial reaction zones. If, for example, the control inputs are combined into independent independent reaction zones by means of horizontal loops circulating over the reaction chamber, the reaction zones which are independent of one another can be operated in parallel and thus combined to form a larger reaction zone.

This variation of the geometry of reaction zones can also be realized by the change, amount and composition of the gasification agent in the radial direction. In this way, inactive, "cold" interior areas are avoided, the entire reaction space is thus activated in terms of process technology, and finally it is possible to vary the respective chemical reaction in the individual reaction zones During operation of the reactor, it is possible to change, change, spatially expand or accelerate the reactions at any point in the reaction space during operation of the reactor.

By way of example, the melting of the solid fuel into readily volatile pyrogas, charcoal, water, higher-chain hydrocarbons, ie a so-called pyrolysis reaction, may be mentioned. The aim is to achieve a high heat input with as little air supply as possible. This is done by preheating the gasification agent, by supplying superheated steam and by external preheating of the solid fuel.

Switching the zone reaction of pyrolysis in the solid fuel to oxidation in the coal bed occurs when, after filling and during start-up of the reactor, the lower zones are initially filled with solid fuel and pyrogenic be operated table. After the outgassing of the volatile pyrogase, the zone is then switched to oxidative or reductive operation.

The gas phase reaction can take place both oxidatively in the solid fuel-free and carbon-free regions produced by intermediate bottoms. The gas phase reaction can be proportionally reduced by greatly increasing the velocity of the gasifying agents by supplying them by means of controllable nozzles without increasing the mass flow, as long as the stream, so-called "sharp jet", strikes the coal bed located behind the cavity.

Furthermore, it is possible to vary predominantly with oxidation or predominantly with reduction in the coal bed. It is also possible to realize oxidation and reduction simultaneously in the same volume of space in the coal bed. It is also possible to operate oxidation and reduction alternately in the same volume of space in the coal bed. This is done by feeding a zone of air with release of heat. Subsequently, the same zone is charged with water vapor and thus generates a water gas reaction while consuming heat. The change of both reactions occurs intermittently during operation.

Finally, the reaction rate in the reaction zones can be varied. For example, in pyrolysis, by reducing the gasification agent supply, the pyrolysis reaction is stopped and greatly reduced. At the same time, the gasification agent supply in the coal bed is increased. The reduction in the supply of gasification equals a reduction in its geometry and / or a reduction in the reaction rate in this zone. The increase in the supply of gasification is associated with an increase in their geometry and / or with an increase in the reaction rates of the reactions occurring therein, so that the carbon is degraded oxidatively or reductively. The pyrozone is geometrically reduced or reduced in intensity, while the reaction zones for coal mining increased, or increased in intensity. Finally, the amount, composition, temperature or pressure of the gasifying agent in the reaction zones can be varied. A variation of the amount of the gasifying agent essentially affects the Reaction speed and partly on the nature of the reaction. The composition of the gasifying agent also affects the nature of the reaction. The temperature variation causes a change in the reaction rate. A variation of the pressure in turn affects the speed and amount of the gasifying agent. A - as far as possible - decoupling of all influencing variables is achieved via adjustable nozzles.

The invention will be explained in more detail with reference to two embodiments with reference to the drawing figures. Show it:

1 is a gasification reactor with loops,

Fig. 2 is a gasification reactor with central hedgehog-like supply line and

Fig. 3 is a schematic representation of the control and control variables with their mutual influence.

Identical parts are always provided with the same reference numerals.

The embodiment in Fig. 1 relates to a gasification reactor 1, which is designed in particular for the gasification of solid carbonaceous fuel. For this purpose, the gasification reactor 1 is designed as a fixed bed reactor according to the DC principle. The gasification reactor according to FIG. 1 is suitable for carrying out the process according to the invention.

The gasification reactor 1 has a permeable intermediate bottom 2, which divides the gasification reactor 1 into an upper reservoir 3 and into a lower reaction chamber 4. Another permeable intermediate bottom 5 separates the reaction chamber 4 from the ash box 6 as the lowest subspace of the entire gasification reactor 1 from. A gas-permeable retention device 7 in the form of a grate between the reaction chamber 4 and the ash box 6 ensures that the fuel remains in the reaction chamber 4. At the ash box 6, a gas outlet 8 is attached. Via the reservoir 3, the carbonaceous, solid fuel is fed to the reaction chamber 4, the useful gas is discharged via the gas outlet 8. After filling reservoir 3 and reacting Onskammer 4 with the carbonaceous solid fuel, the gasification reactor is ignited once in the lower reaction zones and then started by air.

The side wall 9 of the reaction chamber 4 of the gasification reactor 1 is interspersed with a plurality of control inputs 10 in such a way that in the operation of the gasification reactor each position within the reaction chamber 4 is accessible through the control inputs 10. The control inputs 10 are horizontally over the reaction chamber circulating ring lines 11 to flat, but summarized independent reaction zones. By the respective independent ring lines 11 the addition of gasification agent or the return of the reactor internal gas with respect to composition, temperature and pressure and thus quantity is then controlled via the combined via web connections 12 control inputs 10. The control is individual for each area reaction zone.

The reservoir 3 of the gasification reactor 1 has a larger diameter and a larger volume than the reaction chamber 4, wherein the permeability of the intermediate bottom 2 is given by an opening with a diameter which is smaller than that of the reservoir 3 and the reaction chamber 4, but greater than the opening of the intermediate bottom 5 is. The reactor with its reservoir 3, the reaction chamber 4 and its ash box 6 are cylindrical, the openings of the shelves 2 and 5 are circular. This embodiment of the gasification reactor 1 allows its embedding in a vollumschließende insulation, whereby the reactor efficiency is further increased. Regarding the stability in its construction, the gasification reactor 1 is designed to withstand deflagration of the gasification products as well as the fuel.

The gasification reactor 1 according to FIG. 2 likewise has an upper reservoir 3 and a permeable intermediate bottom 2. The reaction chamber 4 is charged by nozzle-shaped nozzle entrances 13 arranged in the form of a nozzle. The nozzle entrances 13 form the control inputs 10 of the embodiment in FIG. Incidentally, the gasification reactor 1 according to Hg. 2 corresponds in its construction to that in FIG. 1.

The control variables determined via the control inputs 10 of the gasification reactor together with the control variables influencing the gasification agent are shown in FIG. Control parameters which can be directly influenced by the control are here the total amount of gasification agent 20, the admission pressure 22 of the gasification agent at the nozzle or control inputs 10, 13, the respective distribution 24 of the gasification agent to the individual nozzle or control inputs 0, 3, that of a spatial distribution corresponds to the temperature 26 of the gasifying agent and the water vapor content 28 in the gasification agent.

As measured in the reactor 1 controlled variables are detected: the flow 30 of the generated Nutzgases, the differential pressure 32 on the lower shelf 5, the chemical Nutzgaszusammensetzung 34, the pressure 36 in the reaction chamber 4, the temperature 38 in the reaction chamber 4 at the respective control input 10 and the type of reactions occurring 40. The latter can typically not be measured directly but can only be determined as a derived controlled variable.

3 shows the respective relationships between control and control variables, as they are used in the method according to the invention, if necessary. The volume flow 30 of the useful gas is influenced by the total amount of gasification agent 20, since an increased supply of gaseous gasification agent via a gain factor Nutzgases increased. Furthermore, this is influenced by the water vapor content 28 in the gasification agent, since introduced water vapor is split reductively and thus causes an increase in the volume and thus the volume flow 30 of the exiting useful gas.

The differential pressure 32 across the intermediate bottom 5, which is permeable to gas, is essentially an indicator of an increased deposition of carbon residues blocking the gas throughput of the intermediate bottom 5. Carbon remains at lower temperatures when the carbon is not burned. This is particularly the case with a high water vapor content 28. Thus, the water vapor fraction 28 influences the differential pressure 32. If the distribution 24 of the supplied gasification agent is changed such that more gasification agent is introduced at control inputs 10 in the region of the intermediate bottom 5 and the temperature here increases, the accumulated carbon is burned and the differential pressure 32 decreases.

The gas composition of the useful gas 34 depends essentially on the proportion of the water vapor 28. A higher amount of water vapor leads to a higher proportion of hydrogen in the useful gas.

The pressure 36 in the reactor chamber 4 should not deviate too far from the ambient pressure. It is essentially influenced by the total quantity 20 of the gasification agent supplied, and also by the spatial distribution 24 of the gasification agent.

The temperatures 38 in the various regions of the reactor chamber 4 are influenced above all by the spatial distribution 24 of the gasification agent, but also by admission pressure 22 and temperature 24 of the gasification agent, as well as the water vapor fraction 28 in the gasification agent, as explained above.

The type of chemical reactions occurring 40 is also, as already explained, essentially determined by the water vapor content 28 in the gasification agent, and also by the temperature of the introduced gasification agent.

The control according to the inventive method now takes into account the control variables recorded in the reactor 1 and accordingly sets the control variables for optimized gasification. The gasification reactor 1, operated with a method under control of the variables described in this embodiment is designed for a CHP, so for the heat and power.

Through thermal integration of all subsystem units of the entire system, combined heat and power generation achieves an overall efficiency of> 90%. LIST OF REFERENCE NUMBERS

1 gasification reactor

2 intermediate floor

3 reservoir

4 reaction chamber

5 intermediate bottom

6 ash box

7 restraint device

8 gas outlet

9 side wall

10 control input

11 ring line

12 bridge connection

13 nozzle entrance

20 total gasification amount

22 form

24 distribution

26 temperature

28 water vapor content

30 volume flow

32 differential pressure

34 useful gas composition

36 pressure

38 temperature

40 reaction type

Claims

claims

1. A method for operating a gasification reactor (1) with a reaction chamber (4) for the autothermal and / or allothermal gasification of carbonaceous fuel to Nutzgasen, wherein

Composition (28), amount (20), pressure (22), speed, temperature (26) and / or specific exit pulse of a gasification agent added via control inputs (10) of the reaction chamber (4) variable based on a number of in the reaction chamber (4) controlled variables (30, 32, 34, 36, 38, 40) are controlled,

characterized in that

the composition (34) of the Nutzgases and / or

the volume flow (30) of the Nutzgases and / or

the respective pressure (36) in a reservoir (3) for the fuel, in the reaction chamber (4) and / or in a gas outlet (8)

can be used as a controlled variable (30, 32, 34, 36, 38, 40).

2. The method according to claim 1,

characterized by

the reaction chamber (4) has a plurality of control inputs (10) and composition (28), quantity (20), pressure (22), speed, temperature (26) and / or specific exit pulse of the gasification agent added via the respective control input (10) partly independently of the other control inputs (10) are controlled.

3. The method according to claim 1 or 2,

characterized by in that the quantity of the carbonaceous fuel material supplied to the reaction chamber (4) is variably controlled on the basis of a number of controlled variables (30, 32, 34, 36, 38, 40) determined in the gasification reactor (1).

4. The method according to any one of claims 1 to 3,

characterized by

in that a temperature (38) in the reaction chamber (4) is used as controlled variable (30, 32, 34, 36, 38, 40).

5. The method according to claim 4,

characterized by

the composition (28), quantity (20), pressure (32), speed, temperature (26) and / or specific exit pulse of the gasification agent added via the respective control input (10) based on the temperature (38) in the reaction chamber (4) the respective control input (10) as a controlled variable (30, 32, 34, 36, 38, 40) are controlled.

6. The method according to any one of claims 1 to 5,

characterized by

in that the pressure difference (32) is used as a control variable (30, 32, 34, 36, 38, 40) via a gas-permeable retention device (7) between the reaction chamber (4) and an ash box (6) of the gasification reactor (1).

7. The method according to any one of claims 1 to 6, are used in the composition, moisture, particulate matter and / or dust content of the fuel as controlled variables (30, 32, 34, 36, 38, 40).

8. Gasification reactor (1) with means for carrying out the method according to one of claims 1 to 7.