DE102007036514A1 - Production of synthesis gas from diverse biogenic solids, pyrolyzes feedstock, burns gases evolved sub-stoichiometrically, then reacts with solid carbon - Google Patents

Abstract

The biogenic feedstock (1) is pyrolyzed, producing a gas of high calorific value. This is then is heated to 1000[deg] C to 1200[deg] C, by sub-stoichiometric combustion with a controlled supply of air. Solid carbon is then added and converted to fuel gas components. The biogenic material is initially carbonized at low temperatures of 350[deg] C to 550[deg] C, in an indirectly-heated rotary reactor (3). Air supplied to the high calorific value gas, burns carbon monoxide and hydrocarbons exothermically (4), to reach the higher temperatures. The gas at 1000[deg] C to 1200[deg] C, contains long-chain hydrocarbons which are broken down into short-chain compounds. This forms a fuel gas suitable for motive power applications, e.g. for burning in a gas engine. The fuel gas is then brought into contact with solid carbon in a post-gasification reactor (5). An endothermic heterogenic water-gas reaction ensues, at about 800[deg] C. This converts the solid carbon into gaseous carbon monoxide and hydrogen, i.e. a combustible synthesis gas (2). This gas is cooled in stages and purified by dust removal. The reactor (5) takes one of various alternative forms, as follows. It is a cyclone which swirls the solid carbon particles in the gas. It is a rotating tube keeping the particles in motion against its inner wall. It is a fluidized bed suspending the particles above a gas-permeable grate. A gas scrubber and/or a fine particle filter, follow the post-gasification reactor. A synthesis gas burner follows the reactor, to recover thermal energy. An independent claim IS INCLUDED FOR corresponding plant.

Description

The The invention relates to a process for producing a synthesis gas from a biogenic substance.

Furthermore The invention relates to a device for generating a synthesis gas from a biogenic substance.

The Generation of a for the energetic utilization of suitable synthesis gas from biogenic Solid material is always gaining due to the progressing climate change more important. Therefor are basically suitable several process variants. As an example, the classic fixed-bed gasification for wood or the fluidized bed gasification of sewage sludge.

The previously used recovery methods were each suitable for certain biogenic substances. So was for the recovery of a synthesis gas from wood primarily uses fixed-bed gasification, in which the wood was slobbered. Sewage sludge often became one Fluidized bed gasification supplied. The training of a facility for the recovery of synthesis gas from many different Starting materials lacked so far, allowing a detailed development was absent from such facilities.

task The present invention is therefore a process for recovery indicate a synthesis gas, with different starting materials can be operated.

The solution This task consists in a procedure, which in a first step from the biogenic substance by pyrolysis generates a high calorific gas, in a second step by substoichiometrically controlled addition of air is heated to temperatures between 1,000 ° and 1,200 ° C and in one third step in addition solid carbon is converted to fuel gas components.

Regarding the apparatus for generating a synthesis gas from a biogenic Substance, the task is solved by the blaze of the biogenic substance provided under Luftabschluss a heated rotary reactor is that over a connecting tube with a device for cracking long-chained Hydrocarbons linked in short-chain compounds, in the temperatures between 1,000 degrees and 1,200 degrees Celsius regulated addition of air can be achieved, and the device for Cracken a post-gasification reactor is downstream, in the solid Carbon with the hot gas can be converted to a synthesis gas.

aid this method can numerous applications be used for the production of a synthesis gas. The procedure not only provides the opportunity to disposal, Previously known method, for example, the wood felling significantly improve and increase the yield of synthesis gas. Much more the process also biogenic substances are accessible, previously for the production of syngas have not been used, such as sewage sludge, Straw, garbage and other products from which so far syngas has not yet won could be.

The to be used plant consists essentially of plant parts, which are known from the process engineering, so they only meaningfully interconnected, so from the respective Product synthesis gas can be obtained. This is unnecessary the development of new plant components, so that the plants for the production of the Synthesis gas are relatively inexpensive and the extraction of Synthesis gas can be made accessible in a simple manner. To this purpose can appropriate facilities are to be built in places where the incurred each to be used biogenic substances.

According to one preferred embodiment of Invention is the biogenic substance under exclusion of air at temperatures between 350 ° and 550 ° C in indirectly heated rotary reactor. By indirect heating the rotating reactor is guaranteed that the smoldering of the biogenic substance under severe exclusion of air takes place.

According to one another preferred embodiment The invention are characterized by the supply of air in the heat rich Gas contained in this combustible fractions of carbon monoxide and Hydrocarbon causes an exothermic reaction, by the temperature of the gas is raised to 1,000 ° to 1,200 ° C. The used for it Plant parts must after all, the relatively high temperatures can withstand. she can but also in this embodiment be purchased from the relevant plant manufacturers. After all, arise the relatively high temperatures, without the carbonization even more Energy supplied must become.

According to one another preferred embodiment In the gas heated at 1,000 ° to 1,200 ° C., the long-chain ones of the invention are used Hydrocarbon compounds cracked into kuzkettige connections and thereby generates a fuel gas accessible to engine combustion. Also for For these purposes, a part of the plant is available that at appropriate Manufacturers can be purchased without significant New constructions become necessary.

According to one another preferred embodiment the invention, the fuel gas in the way of the gasification with a solid carbon, in which by an endothermic heterogeneous Water gas reaction of solid carbon at about 800 ° C in gaseous carbon monoxide and hydrogen is reacted and a synthesis gas with the flammable Ingredients Carbon monoxide and hydrogen are formed. Conveniently, will for this Re-gasification the fuel gas with a solid carbonaceous Residue associated with the pyrolysis. This creates intensive use of the biogenic substance, including its carbonaceous residue. On the other hand unnecessary the procurement of other carbon-rich substrates.

According to one another preferred embodiment According to the invention, the synthesis gas is cooled in various steps as well cleaned of dust particles. The resulting synthesis gas possesses Properties that are without big Effort to be burned in a burner and thus contribute to the production of heat energy to deliver.

According to one another preferred embodiment The invention is followed by the rotary reactor downstream of the gasification reactor. In this way creates a series connection, which has the advantage of offers easy assembly. The laying of complicated pipelines Needless yourself.

According to one another preferred embodiment the invention is the rotary reactor as an indirectly heated rotary tube formed, which is provided with a discharge screw. Also need such equipment parts no separate development times, but can be used for a variety of applications become.

According to one another preferred embodiment the invention is the rotating reactor as an indirectly heated screw reactor educated. Depending on the type of biogenic substance, the Application of one or the other part of the plant. The Selection drops the relevant Professional not difficult.

According to one another preferred embodiment The invention is for the controlled addition of air to the through Pyrolysis incurred high calorific gas a side channel blower provided, the control device to control the in the heizwertreiche Gas to be entered in the direction of one of the high-calorific value Gas flowed through Pipeline downstream. This addition of air requires control, the dependent from the regulation of the desired Temperature is. Correspondingly the control devices are adjusted.

According to one another preferred embodiment the invention is the post-gasification reactor as one with a swirling formed of the solid carbon particles provided cyclone. such Cyclones are also used in other fields of technology, so that they are familiar to the professional world and easier for the special purpose lay out and insert into the system can.

According to one another preferred embodiment In the invention, the post-gasification reactor is one of the solid carbon particles formed on tube walls in motion holding rotary tube. such Rotary tubes are of high technical perfection and therefore can also for the gasification process used at relatively low Temperatures takes place.

According to one another preferred embodiment According to the invention, the post-gasification reactor is one moved on a conveyor Fixed bed of hydrocarbons formed over which the hot gas stream is conductive. These fixed bed reactors enjoy a high technical perfection, so that reckoned with a good gasification that can lead to that a high-energy synthesis gas is produced.

According to one another preferred embodiment In the invention, the post-gasification reactor is one on an air-permeable grate formed fluidized bed of carbonaceous matter, the hot ones Gas flows through is. Such an arrangement is particularly suitable for granular material, that on cheap Way of hot Gas flows through is and thus easily its carbon content to the gas can deliver.

According to one another preferred embodiment The invention is the gasification downstream of the gasification reactor. This gas wash can change the circumstances be set up accordingly, so that out of the gas all Components rinsed out that can be oppose its use as a synthesis gas to operate burners could.

According to one another preferred embodiment In the invention, the post-gasification reactor is a fine particle filter downstream. This also ensures that the synthesis gas from a purity that can be used in burners without Fine particles optionally nozzles or other fine flow devices can enforce.

According to a further preferred Ausfüh In accordance with the invention, the post-gasification reactor is followed by a burner burning the synthesis gas for the purpose of obtaining heat energy. For this purpose, all burners can be used that have already proven themselves in thermal energy systems.

Further Details of the invention will become apparent from the following detailed Description and attached drawings, in which a preferred embodiment the invention is illustrated, for example.

In show the drawings:

1 a block diagram showing the essential process stations and

2 an overview of a circuit diagram.

A device for generating a synthesis gas 2 from a biogenic substance 1 consists essentially of a rotating reactor 3 , a partial oxidation 4 and from a gasification reactor 5 , The rotating reactor 3 is over a connecting pipe 6 with a junction 7 connected, through the air 9 working in a side channel blower 8th in the partial oxidation 4 is initiated. Here are the side channel compressor 8th control equipment 10 . 11 downstream, which is the flow of air 9 so control the temperature of the gas in the area of partial oxidation 4 kept constant.

After the partial oxidation 4 the highly heated gas enters the post-gasification reactor 5 , This can be like the example of 2 shown to be designed as a cyclone. However, it is also possible, instead of the cyclone, a rotary tube, a fixed bed or a fluidized bed as Nachvergasungsreaktor 5 use. The selection can be made according to the respective mixing ratios. Thus, in the cyclone, the mixture of solid carbon and hot gases is kept in suspension by the turbulence of the gas, so that an endothermic heterogeneous water gas reaction can be established, by which the solid carbon is converted into gaseous carbon monoxide and hydrogen at about 800 ° C. This creates the synthesis gas 2 that has a pipeline 12 in a gas scrubber 13 is initiated. this gas scrubber 13 is with a water pipe 14 connected by the washing water 15 under the pressure of a booster pump 16 into the scrubber ( 13 ) enters and is fogged there. This creates a water mist through which the from the Nachvergasungsreaktor 5 derived synthesis gas 2 is subjected to a wash.

Instead of a cyclone other Nachvergasungsreaktoren can be used, for example, not shown rotary tube. In this rotary tube is dependent on the biogenic substance 1 resulting solid pyrolysis residue loosened, so that from the partial oxidation 4 emerging hot fuel gas can come into direct contact with the carbon, which is due to the loosening of the pyrolysis residue within the rotary tube.

Furthermore, depending on the type of pyrolysis residue as the post-gasification reactor 5 also a fixed bed can be considered. The hot gas stream emerging from the partial oxidation is passed through this fixed bed, so that the endothermic heterogeneous water gas reaction can be established on the surface of the fixed bed, in which the solid carbon is converted into gaseous carbon monoxide and hydrogen. Finally, it is also possible in the post-gasification reactor 5 to form on a conveyor a fluidized bed of a correspondingly formed pyrolysis residue. This fluidized bed is relatively loose on the conveyor, so that they from the partial oxidation 4 exiting hot fuel gas can be flushed. Also, this results in a close contact between the carbonaceous pyrolysis residue and the hot fuel gas, so that the solid carbon is converted into gaseous carbon monoxide and hydrogen. These separable components constitute a substantial proportion of the high-calorie synthesis gas 2 ,

After this synthesis gas 2 in the scrubber 13 it is cleaned by a collecting vessel 18 passed through and passes through a pipeline 19 into a filter 17 one. It can then again through an electrostatic precipitator 20 be passed through. It then has a quality that puts it in the state, together with combustion air 21 in a burner 22 to be burned. The resulting heat, for example, in a boiler 23 used to evaporate water. This steam can be used for a variety of cases, for example for driving turbines. The burner 22 leaves an exhaust 24 that has an induced draft fan 25 is disposed of.

As biogenic substance 1 all carbonaceous products are considered, which can be verschwelt, such as sewage sludge, straw, garbage and other products. The process is to be controlled according to the starting material used in each case. For example, the rotating reactor 3 through his drive 26 depending on the consistency of the biogenic substance 1 with higher or lower speeds, for example, its screw 27 operate. It is also possible to use one as indirect heating of the rotary reactor 3 provided burner 28 depending on the required heat of the rotary reactor 3 To produce more or less high temperatures, which lead to a hot air flow through a heating cable 29 to the rotating reactor 3 is brought to the heating of the surface. For this purpose, the burner 28 with natural gas 30 heated, with the help of an airflow 31 in the burner 28 is burned.

The biogenic substance 1 gets into a collection container 32 entered, from which he with a conveyor 33 via another collection container 34 the rotating reactor 3 is supplied. In this case, the conveyor 33 also be designed as a homogenizer containing the biogenic substance 1 before it is filled into the collection container 34 homogenized, so that he smoldering within the rotary reactor 3 is easily accessible.

Claims (18)

Process for producing a synthesis gas from a biogenic substance, characterized in that, in a first step, the biogenic substance ( 1 ) is produced by pyrolysis a high calorific gas, which is heated in a second step by substoichiometrically controlled addition of air to temperatures between 1000 ° and 1200 ° C and in a third step additionally solid carbon is converted to fuel gas components. Process according to claim 1, characterized in that the biogenic substance ( 1 ) with exclusion of air at temperatures between 350 ° and 550 ° C in an indirectly heated rotary reactor ( 3 ) is wasted. Method according to claim 1 or 2, characterized that by feeding of air in the high-calorific gas contained in this combustible Proportions of carbon monoxide and hydrocarbons to an exothermic Reaction caused by the temperature of the gas 1,000 ° to 1200 ° C raised becomes. Method according to Claims 1 to 3, characterized that in the at 1000 ° to 1200 ° C heated Gas the long-chain hydrocarbons into short-chain compounds be brought and thereby accessible to the engine combustion fuel gas is produced. A method according to claim 1 to 4, characterized in that the fuel gas is brought into the way by the gasification with a solid carbon in which is converted by an endothermic heterogeneous water gas reaction of the solid carbon at about 800 ° C in gaseous carbon monoxide and hydrogen and a synthesis gas ( 2 ) with the combustible constituents carbon monoxide and hydrogen. Process according to Claim 5, characterized in that the synthesis gas ( 2 ) is cooled in various steps and cleaned of dust particles. Device for generating a synthesis gas from a biogenic substance, characterized in that for bleaching of the biogenic substance ( 1 ) under exclusion of air a heated rotary reactor ( 3 ) is provided, which via a connecting tube ( 6 ) is connected to a device for cracking long-chain hydrocarbons into short-chain compounds, in which temperatures between 1000 ° and 1200 ° C can be achieved by controlled addition of air and the device for cracking a Nachvergasungsreaktor ( 5 ) is followed, in the solid carbon with the hot gas to a synthesis gas ( 2 ) can be implemented. Apparatus according to claim 7, characterized in that the rotary reactor ( 3 ) in series the post-gasification reactor ( 5 ) is connected downstream. Apparatus according to claim 7 or 8, characterized in that the rotating reactor ( 3 ) is formed as an indirectly heated rotary tube, which is provided with a discharge screw. Apparatus according to claim 7 or 8, characterized in that the rotating reactor ( 3 ) is designed as an indirectly heated screw reactor. Device according to one of claims 7 to 10, characterized in that for the controlled addition of air to the heat-rich gas resulting from the pyrolysis, a side channel compressor (( 8th ), the control equipment ( 10 . 11 ) for controlling the amount of air to be introduced into the high-calorie gas in the direction of a high-calorific gas flow through connecting pipe ( 6 ) are connected downstream. Device according to one of claims 7 to 11, characterized in that the gasification reactor ( 5 ) is formed as a cyclone provided with turbulence of the solid carbon particles. Device according to one of claims 7 to 11, characterized in that the gasification reactor ( 5 ) is formed as a rotary tube holding the solid carbon particles on tube walls in motion. Device according to one of claims 7 to 11, characterized in that the gasification reactor ( 5 ) is formed as a fixed bed of carbon moved on a conveyor over which the hot gas stream is conductive. Device according to one of claims 7 to 11, characterized in that the gasification reactor ( 5 ) is formed as a lying on an air-permeable grate fluidized bed of solid carbon, which is traversed by hot gas. Device according to one of claims 7 to 15, characterized in that the gasification reactor ( 5 ) a gas scrubber ( 13 ) is connected downstream. Device according to one of claims 7 to 16, characterized in that the post-gasification reactor ( 5 ) a fine particulate filter ( 17 ) is connected downstream. Device according to one of claims 7 to 17, characterized in that the post-gasification reactor ( 5 ) the synthesis gas ( 2 ) burning burner ( 22 ) is downstream of the recovery of heat energy.