DE102008028241A1 - Thermochemical transformation device for e.g. industrial waste, has snail reactor for drying and pyrolizing materials, and reactor wall with inlet openings for protecting against blockage of gas and/or outlet openings for passing fuel - Google Patents

Abstract

The device (10) has a snail reactor (11) for drying and pyrolizing materials under air exclusion, and a reactor (15) in which partial oxidation is carried out for fragmentation of long-chained tar molecules by under-stoichiometric addition of air. The reactor is filled with pyrolysis coke, pyrolysis gas and water vapor under formation of pyrolysis coke pouring. The reactor is fillable with the coke developed in the snail reactor on the basis of a hauling device (16). A reactor wall has inlet openings for protecting against blockage of gas and/or outlet openings for passing gaseous fuel.

Description

The The invention relates to a device for thermochemical Conversion of biomass, in particular wood and sewage sludge and / or Domestic or commercial waste, in fuel gas, essentially consisting of at least one screw reactor, in which the aforementioned substances are dried under exclusion of air and be pyrolyzed and at least one other reactor in which a partial oxidation by substoichiometric addition of a Gasification agent, in particular air, at least partially a splitting the long-chain tar molecules takes place, the reactor from above with pyrolysis, pyrolysis gas and steam is filled to form a pyrolysis coke bed, and the residues removed by means of a trigger device below become.

A Such a device from the prior art is already known in principle and serves to carry out the so-called Wiking method, which is not printed is assignable.

The Prior art apparatus has a screw reactor on, in the biomass, preferably wood chips, dried and is pyrolyzed. From the screw reactor reaches the pyrolysis gas, the residues of the pyrolysis (pyrolysis coke) and the water vapor in a second reactor. This reactor is considered vertical Cylinder formed with a horizontal grate at the bottom. The pyrolysis coke forms a fixed bed on the grate. The rust is to limit the fixed bed height movable. Above the grate, air is added to the pyrolysis gas and below the grate, the fuel gas and the pyrolysis coke or the residues are deducted.

There In the reactor, a partial oxidation takes place, high temperatures achieved, so that the long-chain tar molecules are largely destroyed. The dedusting of the gas takes place partially when flowing through the fixed bed and further by additional downstream facilities.

Fixed bed gasifier are simple in construction, but in terms of an identical Reaction history of all gas particles on a uniform flow throughout the Gases rely only on an exact particle size distribution the biomass and ensured by a limited size of the reactor can be.

at the usual, relatively low flow rates in the supply of the oxygen-containing gasification agent, is their Effective range in a fixed bed very limited. The for the reduction and tar decomposition required high temperatures, however achieved only in the range of action of the gasification agent. Reach Pyrolysis over colder Areas of the fixed bed in the fuel gas flow, so are high tar contents in the fuel gas not to prevent. The usual large grates favor these flow inhomogeneities. moreover show the various rust constructions again and again, even with the usual pollutant loads mechanical defects and faults.

outgoing from the described prior art is now the task in it, a new device for thermochemical conversion of Biomass, especially wood and sewage sludge and / or domestic or industrial waste to create their susceptibility is reduced and in which the tar content in the fuel gas is significantly reduced.

The solution the object results from the feature of claim 1, in particular the features of the characterizing part, according to which the reactor starting from the take-off device with that in the screw reactor incurred pyrolysis coke fillable is and that the reactor wall against clogging protected inlet openings for the Has gasification means and / or outlet openings for the fuel gas.

The inventive device has first once the main advantage that they have no storage for the Pryolysis coke has provided rust, so that at the stand The technology thus excluded mechanical defects and disturbances are.

Furthermore is arranged through in the reactor wall, against clogging protected inlets for the Gasification and / or outlet openings for the fuel gas a completely trouble-free Operation of the reactor guaranteed because the pyrolysis coke batch is not in the aforementioned openings can penetrate.

at Such a design of the reactor is furthermore advantageous. that the gas flows can optimally react with each other and the entire fuel gas stream is largely tarry.

In a preferred embodiment of the invention, the reactor wall has a plurality of interior extensions extending at least partially in the direction of gravity, in the free space of which the inlet openings for the gasification agent and / or the outlet openings for the fuel gas are arranged. This type of protection of the inlet / outlet ports against clogging also guarantees a trouble-free operation, since the pyrolysis coke bed is not in the vorgenann th openings can penetrate.

at a further advantageous embodiment of the invention arranged in the reactor wall inlet openings for the gasification agent and / or the outlet openings for the fuel gas with gas permeable Protective devices, in particular lattices provided. This from the construction of the reactor vessel simpler embodiment however, also advantageously provides the assurance that No blockages of the inlet and outlet openings are possible. In addition, it is also here a trouble-free Operation possible.

Furthermore is, by in the range of interior extensions arranged inlet openings for the Gasification agent and outlet openings for the Fuel gas, the reactor designed so that the gas flows optimally can react and the entire fuel gas stream extremely tarry is. Overall, a complete results trouble-free Operation, since the pyrolysis coke bed not in the area arranged in the interior extensions Free rooms penetrate and the inlet openings for the Gasification agent or outlet openings for the Fuel gas can clog.

at an advantageous embodiment the invention, the reactor wall has an annular circumferential Interior extension for inlets and a ring-shaped circumferential interior extension for outlet openings.

By this ring-shaped Distributed arrangement of the inlet and outlet openings results on the one hand a good distribution of for the partial reduction necessary gasifying agent, being at the same time over the adjacent, also ring-shaped arranged outlet openings the largely tar-free fuel gas can be deducted.

at a preferred embodiment the invention, the reactor wall has an annular circumferential Interior extension for outlet and one annular each Interior extension for inlets above and below the level of the outlet openings. This will in the area of the annular arranged interior expansions for inlet and outlet openings an intensive reduction of the pyrolysis gas at high temperatures achieved, whereby a particularly tar-free fuel gas is generated.

Further Advantages of the invention will become apparent from the following dependent claims and from the description of an embodiment. Show it:

1 a sketch of a device for thermochemical conversion of biomass,

2 a sectional view of a reactor of the device according to 1 .

3 an enlarged partial section of the reactor according to 2 and

4 a sectional view of another embodiment of a reactor of a device for the thermochemical conversion of biomass.

In the drawings, an apparatus for the thermochemical conversion of biomass, in particular wood and sewage sludge and / or domestic or commercial waste, in total by the reference numeral 10 designated.

Such a device 10 initially has a screw reactor 11 on top of a motor 12 is driven. The screw reactor is via a filling device 13 For example, wood chips H supplied. The screw reactor 11 has a heating device, not shown, whereby the latter supplied wood chips H are heated to temperatures up to 550 ° C. This occurs during a residence time of about 1½ hours in the transport within the reactor 11 under exclusion of air to form pyrolysis gas, pyrolysis and hydrogen.

In a next step, the aforementioned substances via a connecting channel 14 in the manner of a gravity feed a reactor 15 supplied in which takes place under stoichiometric addition of air, a partial oxidation of the pyrolysis gas. The reactor 15 is at its lower end with a rotary valve 16 Mistake. In detail, the reactor 15 described below.

The reactor 15 is also a gas filter 17 including a rotary valve 18 , can be deducted from the residues, and a gas cooler 19 downstream. That from the exit 20 of the gas cooler 18 flowing, purified fuel gas is then supplied, not shown, for example, a gas engine. The electrical energy generated in the gas engine can be fed into the supply network, wherein the heat also generated also the heating of the aforementioned screw reactor 11 can serve.

In the 2 and 3 is the reactor 15 shown in detail. One recognizes in connection with the 1 that in the screw reactor 11 resulting pyrolysis coke, including the pyrolysis gas and the water vapor, via the connecting channel 14 falls into the reactor interior and there, starting from the gas-tight rotary valve 16 a pyrolysis coke bed 21 results. The pyrolysis coke bed 21 has a repose angle S.

The reactor 15 has circumferential walls 22 , which are constructed mehrschalig. In the wall 22 is a ring R _B of individual fuel gas outlet pipes 23 , a ring R _Vo above the aforementioned ring R _B of gasification agent inlet lines 24 and a ring R _Vu from below the fuel gas exhaust ducts 23 arranged gasification agent inlet lines 25 arranged.

In addition, the reactor has 15 different cross sections. In the upper area is the reactor 15 provided with the cross section D ₁ , located in the upper gasification agent inlet openings 24 extended stepwise to a cross section D ₂ . As in particular in 3 can be seen, this results in the upper gasification agent inlet openings 24 due to the Schüttwinkels S pyrolysis coke an automatic clearance 26 by which it is always ensured that there is no clogging of the gasification inlet lines 24 comes.

Below the reactor region with the cross-section D ₂ , a further expanded cross-sectional area D ₃ is furthermore arranged, the fuel gas outlet openings being arranged annular in the transition area. Again, there is the effect that the fuel gas outlet pipes 23 within the open space 27 , ie in the region of the change in cross section of the reactor 15 , are arranged so that the fuel gas outlet pipes 23 safely protected from blockages.

Ultimately, the reactor has 15 an in turn extended cross-sectional area D ₄ , wherein in the transition region, the free space 28 in the transition region from the cross section D ₃ to the cross section D ₄ , the lower ring R _{Vu of} the gasification agent inlet lines 25 is arranged protected.

Below the above described oxidation zone is ultimately a funnel 29 for the residues from the partial oxidation present, through which the residues to the rotary valve 16 be guided.

In the 4 is another embodiment of a reactor 15 shown. The reactor 15 also has a circumferential, vertical wall 22 on, which is constructed mehrschalig. In the wall 22 are gasification agent inlet lines 24 and fuel gas outlet lines 23 however, these are in the region of their exit into the reactor 15 with vertically arranged protective grids 30 are provided, the entry of pyrolysis and the clogging in the gasification agent inlet lines 24 or in the fuel gas outlet lines 23 should prevent.

Although the reactor has 15 according to the embodiment 4 vertical walls 22 However, it is also conceivable that these walls 22 expand downwards so that, if necessary, the protective grille 30 not 90 ° to the horizontal, but are arranged at a smaller angle to the horizontal.

Claims (10)

Device for the thermochemical conversion of biomass, in particular wood and sewage sludge and / or domestic or commercial waste, in fuel gas, essentially consisting of at least one screw reactor in which the aforementioned substances are dried and pyrolyzed under exclusion of air and at least one further reactor, in which a partial oxidation by sub-stoichiometric addition of a gasification agent, in particular air, at least partially splitting of the long-chain Teermoleküle takes place, wherein the reactor from above with pyrolysis coke, pyrolysis gas and water vapor is filled to form a Pyrolysekoksschüttung, and the residual materials are withdrawn by means of a withdrawal device below, characterized characterized in that the reactor ( 15 ) starting from the extraction device ( 16 ) with the in the screw reactor ( 11 ) Pyrolysiskoks is fillable and that the reactor wall against clogging protected inlet openings ( 24 . 25 ) for the gasification agent and / or outlet openings ( 23 ) has for the fuel gas. Apparatus according to claim 1, characterized in that the reactor wall has a plurality of in the direction of gravity at least partially extending interior expansions, in the free space ( 26 - 28 ) the inlet openings for the gasification agent ( 24 . 25 ) and / or the outlet openings ( 23 ) are arranged for the fuel gas. Device according to claim 1, characterized in that this is the inlet openings arranged in the reactor wall for the Gasification means and / or the outlet openings for the fuel gas with gas-permeable protective devices, in particular lattices are provided. Apparatus according to claim 1, characterized in that the reactor wall an annular circumferential interior extension for inlet openings ( 24 . 25 ) and an annular circumferential interior extension for outlet openings ( 23 ) having. Apparatus according to claim 1, 2 or 3, characterized in that the reactor wall an annular circumferential interior extension for outlet openings ( 23 ) and in each case an annular interior extension for inlet openings ( 24 . 25 ) above and below the level of the outlet openings ( 23 ) having. Device according to one of the preceding claims, characterized in that the interior expansions are formed in stages are. Device according to one of claims 1 and 3 to 6, characterized characterized in that the interior extension formed from a diagonal surface is, which has an angle to the horizontal of the smaller is considered the angle of repose of the pyrolysis coke. Device according to one of the preceding claims, characterized in that between the interior extensions of the reactor 15 provided with vertical wall areas. Device according to one of the preceding claims, characterized in that at the lower end of the reactor ( 15 ) a rotary valve ( 16 ) is arranged for the residues. Device according to one of the preceding claims, characterized in that the reactor ( 15 ) is constructed at least partially double-walled and between the wall sections inlet pipes ( 24 . 25 ) for the gasifying agent and outlet pipes ( 23 ) are arranged for the fuel gas.