DE102006058673A1 - Weak gas producing device for energy production, has helical conveyor i.e. agitation device, and inner wall of reactors arranged for maximum temperature adapted materials obtained in thermal processes - Google Patents

Abstract

The device has a helical conveyor (1) i.e. agitation device, arranged in a lower area of the device to ensure complete burnout by adding an oxidant (4) i.e. air. The helical conveyor and an inner wall of reactors are arranged for maximum temperature adapted materials obtained in thermal processes. An opening is mechanically cleared by the helical conveyor. Gas treatment of a particle charging takes places in a reactor for controlling a charging level of a coke capacity and extracting a carbonic slag. An independent claim is also included for a method for producing weak gas from an organic energy source.

Description

Technical environment

The The invention relates to the field of energy production and of Apparatus construction and relates to an apparatus and method for low-gas production from energy carriers in particular biogenic materials, which used for the production of electric energy and heat can. By means of this device or the method is through Substoichiometric addition of an oxidizing agent, such as Air, water vapor or pure oxygen, produces a lean gas, which motor used for the combined expansion of electricity and heat can be.

In "Energy from Biomass" by M. Kaltschmitt (Springer Verlag, 2001) An overview of the state of the art and the known methods and apparatus for the thermal utilization of biomass for the provision of electricity and heat is shown. In addition to classic technologies of combustion and gasification, modern technologies with downstream motorized use are also named. In addition, the technical challenges in the thermal utilization of biogenic fuels are mapped on the basis of their specific properties.

in the Fixed bed gasifier is the fuel to be gasified in a packed bed, which moves from the point of entry to the ash discharge, the gasification agent exposed. The fuel bed sinks due to gravity and the continuous decomposition in the individual zones slowly downwards from. In relation to the down moving bed the oxidant is added in cocurrent, countercurrent or crossflow. The problem with these designs is especially the uniform Distribution of the gasifying agent over the reactor and the Sensitivity to fuel streakiness. For this, only low energy efficiencies are achieved here.

at The fluidized bed process is differentiated into stationary and circulating fluidized beds. The fluidized bed arises when the gasification agent at a sufficiently high speed flows through the reactor and the bed material and the fuel whirls. The fuel particles are typically clear smaller than in fixed bed reactors. Compared to fixed bed gasifiers in such reactors also no temperature and reaction zones are formed, so that the individual reactions take place in parallel. Advantageous here is the intense heat exchange between bedding material, usually quartz sand, and the energy source. adversely are the high particle load of the gas and the gas quality generated for higher hydrocarbons. Other disadvantages The fluidized bed gasification lie in the high technical expenses and the low cold gas efficiencies.

moreover The known technologies of gasification have high sensitivities regarding the type of fuel. There are differences the calorific values biogenic fuels essentially only by the Water content and are less influenced by the type of biomass and are within a narrow range of 16.4 to 19.2 MJ / kg TS. Other Substance properties, on the other hand, show considerable differences. Out View of the thermochemical processes is particularly on the Ash content, chlorine and sulfur content and the ash melting behavior to pay attention.

On Due to the high process temperatures, physical changes occur of ashes, it can be soaking up to the uttermost Melting come. If there is a low sintering beginning, it can quickly come to caking in the firebox, causing changes Flow and reaction conditions and ultimately to interference can lead the stationary Anla genbetriebes. The risk of such sintering is higher, especially in places So high temperatures in the oxygen supply.

The Ingredients Potassium, calcium and magnesium essentially characterize this behavior. This leads to high potassium and magnesium contents to a lowering of sintering beginning, while through the Addition of calcium-containing materials to the risk of slagging can be reduced by raising the critical temperatures. At the Use of woody biomass is the danger of sintering Reason for the low ash content and the relatively high start of sintering low at about 1200 ° C. Straw as a residue from agriculture has higher ash contents and a lower one Sinter beginning on. Especially grain kernels are problematic as fuel, here can already from 650 ° C Sintering occur.

Out For this reason, all known technologies prefer predominantly Wood with a water content of 20% as an energy source.

Disclosure of the invention

Technical problem

The known techniques for low-gas production have a high sensitivity with regard to the fuel properties, in particular the water content, particulate matter and sintering behavior. To enter the problems in gas quality Relating to tar and dust content. The object of the invention is to provide a device and a method for low-gas production from a variety of energy sources, which allows stable operation and high energy efficiency and good gas quality when using a variety of energy sources.

Technical solution

The Device according to the invention includes the use of the resulting in the partial oxidation of fuels Coke internally as heat carrier for heat recovery. This internal heat utilization can increase the energy efficiency and thus a more effective use of existing energy resources. The For this purpose, the invention includes apparatuses designed for this purpose Reactor in which the thermochemical process takes place, too realize. Furthermore, the invention includes a special apparatus Design at the gas outlet of the reactor to improve the generated Lean gas quality. The inventive Device thus allows for low-gas production a better gas quality.

The Invention consists of a reactor with a transport system and a gas outlet specially arranged at the upper end. In the reactor with the help of a transport device of energy sources transported into the lower area. About one Chute additionally receives hot coke the oxidation zone to the fresh material. In the further transport Due to the mixing of both materials, the cooling of the Coke by heat transfer to the new energy source. This is heated, dried and partly or also completely pyrolyzed. The transport of the material takes place to the middle of the reactor. The transport device is enough the entire cross section of the reactor and transported by both Reactor changing material towards the middle. Here is a second one Transport device or a stirring element in a delimited Room arranged. The material mixture is transported in this high. At the upper end is the addition of the oxidizing agent and the material is thermochemically reacted at high temperatures and becomes a lean gas generated. The transport or stirring device allows in this area the permanent mechanical clearance the supply sites of the oxidizing agent, so slagging and counteract deposits. The gas flows through a large gas space above it. Of the incompletely reacted coke enters the trough-shaped bottom of the reactor towards the manholes at Edge of the reactor. Here on the one hand, the admixture to the new energy source and on the other side of the partial return transport back to the middle of the reactor, where he deals with the other coke and the already pyrolyzed new one Material mixes and thus allows further heating of the new material. The entire mixture is then added transported back to the oxidation zone.

Of Furthermore, the invention includes a further transport device, which the removal of possibly coke-containing ash from the Reactor and its complete conversion allows. This transport device is in a higher level than arranged and enabled the first transport device thus a regulation of the fill level of the coke bed in the reactor. At the same time in this with the addition of oxidizing agent the material is completely thermally converted, as well here the transport device or stirring a constant mechanical clearing of the outlet openings of the Ensure oxidant. The resulting ash is further transported away in a container and the resulting exhaust gas passes through the transport device in the reactor. The arrangement of the transport device can be horizontal or at an angle of up to 45 ° to the Matellinie of the Reactor take place.

The generated in the partial oxidation of the energy sources Gas flows through a large hot gas space and exits at the top. To ensure motor usability, the gas outlet on the reactor is arranged so that the gas in a Gas vortex rises upwards and through the centrifugal forces already in the reactor dirt particles are separated.

Of the Gas outlet is tangential, but inward into the reactor arranged offset in it, so that the inner edge of the gas outlet stands out on all sides from the reactor inner wall. The gas is thereby forced to a vortex flow, in due to the acting centrifugal forces the particles to the reactor wall be transported. By the projecting into the reactor interior gas outlet, does not occur with the particle-laden gas flow of the near-wall flow but a gas stream with less particle loading from the reactor out.

advantageously, the reactor is tubular standing, with round, oval, formed square or rectangular cross-section. In the area below a cross-sectional reduction, preferably channel, semi-tubular or trough-shaped. Here is the first transport device arranged, which over the entire cross section of the reactor Material transported to the center. This device is advantageously a screw conveyor with a slope between 0 and 45 °.

The Adding the fresh material to the hot coke can also via a chute from above into the reactor respectively.

The Internal recycling of the coke as heat carrier takes place from the reactor space in the first screw conveyor over a shaft-like feeder, which with round, oval, square or rectangular cross-section can be formed. The first transport device must be designed so that it after mixing the coke with the removal of this larger Mass flow compared to the fuel mass flow allows. Out For this reason, it is advantageous to use this as a screw conveyor run and increase at the reactor inlet in cross-section.

The first transport device promotes advantageous manner from both sides to the reactor center. Here is a tubular one Shaft with the second transport device arranged. In this Segment the material mixture is transported upwards. At the the upper end of the shaft are the feeder of the Oxidizing agent, such as air, oxygen, water vapor or mixtures this. The second transport device continues to allow the constant mechanical clearance of these openings. Out For this reason, the transport device can be used as a screw conveyor, but also designed as a simple stirring element become.

Farther it is advantageous the first transport device as a perforated Channel or pipe. This makes it possible that pyrolysis gases through the coke bed in the gas space get the reactor and only the bound solid carbon in direct contact with the oxidizing agent comes.

These internal feedback according to the invention of hot coke for heat supply for the Drying and pyrolysis of the fresh energy source can also advantageously via a shaft-like feeder done in a transport device in which it is the necessary Heat for the drying and pyrolysis processes and over the entire length of the reactor is transported to a further transport device. This is advantageously above the first transport device and transports the mixture back to the center of the reactor. There As described above oxidizing agent is added and the outlet openings still mechanically cleared by the transport element. The described Transport devices are advantageously screw conveyor with a slope between 0 and 45 °.

Favorable The oxidizing agent is preheated regeneratively in the reactor under a low compared to the reactor pressure directed. The supply is done via a Distribution ring at the end of the transport device. On the Distribution ring is placed over one or more pipes in the oxidant passed the reactor evenly distributed.

The Weak gas produced follows an upward gas outlet towards Flow, which in the course as vortex flow formed. Due to the special arrangement of the gas outlet, the tangentially but offset inwardly into the reactor takes place is already in the reactor an improvement of the gas quality Separation of particles achieved. For this reason, the gas outlet opening advantageously slot, channel or tubular.

All Transport and stirring devices of the reactor are more advantageous Made of high temperature resistant materials.

By The invention can almost completely provide energy carriers be implemented at a reactor power to preferably 2 MW. Even higher benefits are not fundamental locked out

The inventive method includes the residual drying and pyrolysis of the energy sources in the lowest part of the Reactor with subsequent gasification at high temperatures up to 1200 ° C with the addition of an oxidizing agent.

The addition of hot coke to the fresh organic material and the intensive mixing resulting from further transport provide heat energy for the drying and, subsequently, for the pyrolytic decomposition. In this case, the water vapor is expelled in a temperature range of the fresh material to 200 ° C. Subsequently, the pyrolysis of the material takes place at temperatures up to 700 ° C. The resulting products, consisting of pyrolysis and the gaseous components such as carbon dioxide, water vapor, hydrogen, carbon monoxide and short and long-chain hydrocarbons are further mixed with hot coke from the oxidation zone. The completeness of the pyrolytic decomposition can be adjusted depending on the specific fuel requirements by the residence time and by changing the concrete dimensions of the transport device. Due to the specific configuration of the transport device in a perforated tube, the gaseous pyrolysis products can flow through the coke mixture into the headspace of the reactor so that the resulting mixture of solid pyrolysis materials and the hot coke is conveyed to the exit port of the oxidizer. The oxidant is conveyed through one or more supply lines towards a distribution system and then evenly over egg NEN distribution ring brought into contact with the material. Depending on the position of the second transport device, this feed can be arranged laterally or from above and allows a flow of gas into the upper part of the reactor. This can be achieved by supplying the oxidant under pressure through a plurality of openings and / or by suctioning off the resulting lean gas in the upper region. Since very high temperatures can occur locally at the exit points of the oxidizing agent, there is thus the danger of sintering and ash melts up to deposits and hindrances of the stationary operation. For this reason, these danger spots are permanently mechanically cleared by the second transport device. If the material is not completely converted into gas components, coke is formed. This coke returns at temperatures up to 800 ° C in the lower part of the reactor and provides the heat energy for the drying and pyrolysis of the fresh fuel ready. The resulting gas passes due to the flow in the reactor in the upper region, here at temperatures up to 1200 ° C and by high residence time, the reaction of higher hydrocarbons. In addition, due to the arrangement of the gas outlet, there is a gas vortex flow which makes the residence time uniform and, in addition, allows gas purification with respect to entrained small coke particles due to the centrifugal action. The separated particles return to the coke bed due to gravity. The regulation of the level of this bed and the discharge of inert materials or ash is realized with another transport device. In order to ensure complete conversion, an oxidizing agent, such as air, water vapor, oxygen, oxygen-containing exhaust gas or combinations of these substances is added here again. Again, the risk of sintering is realized by constant mechanical movement of the material at the outlet openings. The resulting exhaust gas returns to the lower part of the reactor and follows the main gas flow to the gas outlet.

In Depending on the throughput or of the residence time is the fuel is essentially transferred to the gaseous state. The reactor thus leaves a low-tar, low-particle weak gas with the main energy sources carbon monoxide, hydrogen and to a lesser extent methane and the other non-combustible Ingredients nitrogen, carbon dioxide and water vapor.

On The reason for the high gas outlet temperature is the extracted lean gas for regenerative preheating of the oxidizing agent or to be used for another heat use. The generated Gas may be available after further purification the motor use for the provision of electric power and Warmth.

When advantageous for the transport devices are screw conveyors, which by adjusting the respective speeds the temperatures and the speeds or residence times of the energy carriers in the individual shareholder parts.

Short description of drawings

The Drawings represent two possibilities for realization the described device and the method. The description takes place on hand of a following embodiment.

The best way, the invention exploit

The Operation of the method in the device is intended to an example embodiment be explained.

The reactor for low-gas production has a total height (excluding feet) of 2.5 m and an inner diameter of 1 m. The screw conveyor ( 1 ) is arranged horizontally on the reactor bottom. The fuel introduced into the reactor is 158 kg / h with an average edge length of 30 mm and a maximum of 100 mm. At the reactor edge, a 6 ) with the width of 100 mm of hot coke is added to the fresh material. During transport of the mixture, the coke is cooled and the heat used for drying and pyrolytic decomposition of the fuel. The screw conveyor goes from the material inlet to the opposite end of the reactor. Here, the material is pushed up in a short round shaft and executed by the second transport device located there as a screw conveyor ( 2 ) conveyed back into the reactor space. The shaft openings for transporting the mixture are chosen so that a free passage is ensured. The resulting gaseous pyrolysis arrive in the gas space of the reactor. This is made possible by passing the two superimposed screws in perforated tubes so that the gases can flow into the reactor and only the solid pyrolysis products to the entry of the oxidizing agent ( 4 ) to get promoted. At the end of the second screw is an oval saddle-shaped opening of the guide tube up to the reactor with a diameter of 300 mm, here distributed over the entire circumference, the oxidizing agent is directed towards directed into the screw. The oxidizing agent used is regeneratively preheated air, which is conducted via a pipeline to the distribution ring. The resulting gas flows up to the gas outlet ( 5 ).

The unreacted coke falls over the upper edge of the pipe in the underlying bed and is mixed with the fresh fuel.

The level is controlled by a third screw ( 3 ), which is arranged tangentially in the reactor. This screw conveyor is located above the lower transport screw but below the upper edge of the second screw. In addition, this screw is arranged at an angle of 90 ° to the other two screw.

In This screw is a low volume oxidant supplied to ensure complete burnout.

The Places where locally high temperatures can occur So in the reactor at the end of the vertical pipe, where the preheated Air is dosed and in the snail, in which the burnout of the Ash is realized mechanically by the screw conveyors or stirrer itself cleared. Thus, slagging and prevents sintering.

Of the hot gas space with a height of 1.8 m is used by flows through the generated lean gas and has temperatures up to 1200 ° C.

in the Reactor, the gas outlet opening is slotted with a Height of 300 mm and a width of 100 mm, so that a gas vortex is created and the gas due to the centrifugal force is freed from entrained particles. The middle of the gas outlet is located at a distance of 350 mm to the reactor center. As a result, the particles transported to the wall are not discharged but fall back to the cylindrical wall in the Coke charge.

The gas volume of 480 Nm ³ / h is extracted with a blower, the thermal energy of the gas is used for regenerative air preheating and other heat utilization and the chemical gas power of 400 kW is used in a Zündstrahlmotor to generate electricity and heat.

1

transport device for material supply

2

second transport device

3

third Transport device or Ausbrandschnecke

4

outlet opening of the oxidizing agent

5

gas outlet

6

shaft openings

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - "Energy from Biomass" by M. Kaltschmitt (Springer Verlag, 2001) [0002]

Claims (30)

Device for the production of weak gas from organic Energy sources in which the costs incurred during the gasification process Coke for internal heat recovery for used the drying and pyrolysis of the energy carrier is, with the energy carrier over a lower Transport device is transported into the reactor and into this Transport device over manhole openings coke fed and mixed with the fuel and in this transport device by the heat emission of the coke to the energy carrier at least the drying but also the further pyrolytic decomposition is enabled, and the mixture transported to a higher level and there the addition of the oxidizing agent takes place, the openings or discharges of the oxidizing agent by the transport devices constantly be mechanically cleared, and over the oxidation zone forms a large hot gas space, through which the gas is caused by a swirling flow by the special tangential cut arrangement and geometry the gas outlet at the upper region of the reactor to the gas outlet opening flows, which already in the reactor gas purification terms Particle loading is done to regulate the level the coke bed and for the removal of possibly carbonaceous Ash is in the device in the lower area another transport device arranged in which the complete burnout Addition of a second oxidizing agent is made possible also here the opening by the transport device is mechanically cleared, here are the transport facilities and the inner walls of the reactor corresponding, for the maximum temperatures achievable in the respective thermal processes taking place suitable, running materials and the exiting generated lean gas is used for energy production. Apparatus according to claim 1, wherein the reactor with round, oval, square or rectangular cross section is trained. Apparatus according to claim 1, wherein the lower transport device has an inclination between 0 and 45 °. Apparatus according to claim 1, wherein the shaft opening or shaft openings for Kokszumischung a circular, have rectangular, square or oval cross-section. Apparatus according to claim 1, wherein the lower transport device in the reactor is enlarged in cross section. Apparatus according to claim 1, wherein the transport device in the reactor is not enlarged, but already in the non-coke leading part sized so large is that the admixture of the coke is guaranteed. Device according to Claim 1, in which the second transport device, with which the mixture is transported to the oxidizing agent, arranged at an angle of 0 to 90 ° to the reactor axis is. Apparatus according to claim 1, wherein the second transport device only as a stirring element is executed. Devices according to claim 1, wherein the lower Transport device on both sides via a chute connected to the reactor and the transport to the reactor center realized. Apparatus according to claim 1, wherein the lower Promotes transport device through the reactor and on the opposite reactor edge the material mixture in the second transport device transfers. Apparatus according to claim 1, wherein the reactor in the lower area towards the lower transport device channel-like or cone-shaped. Apparatus according to claim 1, wherein the transport devices be performed in perforated tubes in the reactor. Apparatus according to claim 1, wherein the mixture of the fresh fuel with the coke is done so that the material fed from above into the reactor, in the reactor bed already mixed and then on a transport device is transported to the oxidizing agent. Apparatus according to claim 1, wherein the transport devices at the same time a constant movement of the material directly at the hot spots of the oxidant supply realize. Apparatus according to claim 1, wherein the object the first and second screw in another transport device is realized. Apparatus according to claim 1, in which the supply of the oxidizing agent via a distributor ring down is realized in the direction of material supply and a Gas flow up through a gas space to the gas outlet he follows. Apparatus according to claim 1, wherein the distribution system the oxidizing agent realized in a ring or rectangular channel is. Apparatus according to claim 1, wherein the gas outlet opening in the upper region of the reactor is arranged above a gas space and has a tangential truncated slot-like, rectangular, round or oval cross-section. Apparatus according to claim 1, wherein the gas outlet opening perpendicular leads from the lid into the reactor and has a tangential entry. Apparatus according to claim 1, wherein the third Transport device horizontally or at an angle of up to 45 ° is arranged. Apparatus according to claim 1, wherein the third Transport device, a regulation of the reactor level allows. Process for low-gas production from organic Energy sources in which the costs incurred during the gasification process Coke for internal heat recovery at least for the drying but also for the pyrolysis of the Fuel is used, with the fresh fuel is mixed with the hot coke and this mixture over a transport system transported to the outlet of the oxidant out is predominantly due to the apparatus design the solid pyrolysis products are reacted with the oxidizing agent, the resulting pyrolysis gases predominantly by those in the reactor existing bed flow and so a partial Allow the coke and pyrolysis gases to be converted and the resulting gases from the overlying oxidation zone and flow out of the pyrolysis a hot gas space, causing a decomposition of higher hydrocarbons is possible, and the resulting gas is an upward directed vortex flow, which in conjunction with the special apparatus design of the gas outlet one Coarse cleaning of the gas flow causes of particles, which in turn go back directly into the coke bed and can be implemented, and the coke in the reactor is regulated by a trigger and completely is reacted by further oxidation, so that the resulting lean gas can be used for energy. The method of claim 22, wherein as organic Energy carrier renewable raw materials, agricultural Residues or other energy-containing organic substances used become. A method according to claim 22, wherein as the oxidizing agent into the reactor air, oxygen, water vapor or mixtures of these be used. The method of claim 22, wherein by the mixture from incompletely converted material from the partial Oxidation process and fresh energy source a heat energy recovery he follows. The method of claim 22, wherein by the internal Heat recovery the partial or complete Drying and / or partial or complete pyrolysis will be realized. The method of claim 22, wherein the complete Burnout of the withdrawn carbonaceous ash with air, water vapor or oxygen-containing exhaust gas or mixtures thereof is realized. The method of claim 22, wherein the oxidizing agent supplied at a higher pressure compared to the reactor becomes. The method of claim 22, wherein the gas flow is realized directed upwards. Process according to claim 22, wherein in the upper reactor a separation of particles takes place and these in the reaction process to be led back.