ES2777307T3 - Reactor for gas extraction from organic waste - Google Patents

Abstract

Reactor (1) for the extraction of gas from organic waste, with a reactor shell (5) in the form of a column, with vertical orientation, which surrounds a reaction space (2), which has a section called accumulation space (3) that can be filled with organic waste, and which presents above the accumulation space (3) a gas space (4) that collects the gas extracted from organic waste, the reaction space (2 ) thermally insulated towards the outside, towards the surrounding atmosphere, and a cleaning chamber (11) joining upwards to the reaction space (2), limiting the interior space of the cleaning chamber (11) with a surface of cooling (15), and leading to a gas outlet conduit (16) that guides the gas extracted out of the reactor (1), in the cleaning chamber (11), and being provided in the gas outlet conduit ( 16) a condensate separator (17), which has a s condensation surface (18) that enters the gas flow as well as a condensate accumulation space (20) that is located below, characterized in that a second gas line called bypass opens into the gas space (4) (22), which also guides the gas extracted out of the reactor (1), the bypass (22) leading to the gas outlet conduit (16).

Description

DESCRIPTION

Reactor for gas extraction from organic waste

The invention relates to a reactor according to the preamble of claim 1.

A reactor of this type is known from EP 0075060 A1.

It is known from EP 2495299 A1 to guide the gases obtained from organic waste through pipes to a separate cleaning tank and to effect gas cleaning there, insofar as condensate is separated from the gas obtained.

From DE 41 03738 A1 a device for converting plastic material into oil is known, and from FR 914272 A3 a device for distillation from fuel is known. From document FR 887439 A a reaction tank is known, which has cooling ribs on its lid, in order to promote the separation of condensate on the inside of the lid. From DE 3131476 C2 a wood gas generator is known, the cover of which is also designed for the separation of double-walled condensate so that it can be cooled by a flow of air. Also document FR 905 858 A describes a wood gas generator. The invention is based on the objective of improving a reactor according to the order in that it allows a safe extraction of the gas as free from disturbances as possible and allows the simplest possible maintenance of the reactor.

This objective is solved by a reactor with the characteristics of claim 1.

The invention proposes in other words, to carry out the cleaning of the extracted gas not only in the cleaning chamber, which is not configured as a separate chamber with respect to the reaction space, but rather allows a free gas flow from the space reaction to the cleaning chamber. According to the proposal, a condensate separator is provided in the gas outlet line, so that additional cleaning of the gas takes place, similar to what is already provided in the cleaning chamber. This condensate separator allows a particularly efficient cleaning of the gas since it results in a complete two-phase gas cleaning as a subsequent cleaning. In this case, the condensate separator has a condensation surface that enters the gas flow as well as a condensate storage space below it, in which the condensate, which accumulates on the condensation surface, may drip.

Depending on the temperature, the gases that are already extracted rise in the reaction space, so that in the proposed reactor design they then automatically enter the cleaning chamber, which joins the reaction space from above. In this case, the gas has a cooling surface, so that condensate is automatically condensed on this cooling surface and the gas cleaned by the condensate can thus be guided through a gas outlet line to the outside of the reactor, the gas outlet conduit leading into the cleaning chamber. In addition to the gas outlet line, which opens with its end into the cleaning chamber and serves to extract the cleaned gases from the reaction chamber, a second gas line is provided according to the proposal to evacuate the gases. extracted gases. This second gas line is called a bypass and serves in particular to evacuate the gases not from the cleaning chamber, but from the gas space of the reactor. This bypass serves as safety equipment: when the mouth opening of the gas outlet pipe gets stuck in the cleaning chamber due to condensation, the temperature inside the cleaning chamber being, for example, in the range of 180 ° C to 200 ° C, it must be assumed that due to the significantly higher temperature level in the gas space of the reaction space, the outlet of the bypass does not clog and correspondingly gas can be guided through the bypass into the outside of the reactor, so that a dangerous pressure rise in the reactor can be avoided.

In this regard, it is also provided in accordance with the proposal that for the simplification of the construction design of the reactor, the bypass must not be configured with any length, but rather opens at its second end into the gas outlet pipe, of so that from here gas can be driven along its usual route.

In a manner known per se, the temperature level in the reaction space can be controlled in such a way that between the thermal insulation, which is provided outside the reaction space, and the reactor shell, which limits the reaction space, a interspace that can be heated. This interspace can, for example, be fed with exhaust gases from a block thermal power plant, the block thermal power plant can for its part operate with the gas, which is generated in the reactor.

The cleaning chamber can essentially advantageously be connected with an internal cross-section that remains the same, upwards with the reaction space, so that the reactor can be regarded as simplified as a standing tube, in whose lower zone the reaction space is provided and its upper zone, above the reaction space, forms the cleaning chamber. The wall of this reactor, considered in a simplified way as a tube, has different wall thicknesses, in that in the lower zone, surrounding the reaction space, the aforementioned thermal insulation is provided, while in the upper zone, where the cleaning chamber, such insulation may have been consciously dispensed with, in order to thus use the tube wall itself as a cooling surface, on which the condensate condenses.

Since the free inner cross-section of the reactor passes essentially unchanged from the reaction space into the cleaning chamber, on the one hand, a fast and problem-free filling of the reaction space from above is possible, inasmuch as, for example, the The reaction chamber is provided with a top cover, which can be configured, for example, as a pivoting or folding cover or as a hatch. In the case of an open lid, organic waste can be introduced into the reactor, it automatically falls through the cleaning chamber into the reaction space to its lower zone, which is called the accumulation space for organic waste. The lid is then closed again and the reaction space is heated, for example to a temperature level of 360 to 430 ° C. Under pyrolytic conditions, ie excluding air, organic waste can now be transformed and gas extracted from it. The gas rises upward in the reaction chamber, thus enters the section called the gas space of the reaction space, and continues to rise from there towards the cleaning chamber, where it enters against the cooling surface.

The operation of the reactor takes place by loads, that is to say, respectively until the complete use or transformation of the organic waste as far as possible. The reactor is then opened and a fresh load of organic waste is introduced into the reactor. Since the organic material is almost completely transformed, only a very small remainder of the non-transformed materials in the reactor remains relative to the initially used volumetric amount of the organic waste. After a certain amount of charges, the reactor can be cleaned and emptied of these remains. The condensate, which condenses on the cooling surface of the cleaning chamber, can flow or drip downwards and there again enters the reaction space, so that a new or given treatment is produced as a feedback. case repeated multiple times of these substances in the reaction space, which favors the complete transformation as far as possible of the organic waste originally introduced.

The condensate separator provided in accordance with the proposal can advantageously be arranged downstream of the point at which the bypass opens into the gas outlet line. In this way, when the gas is withdrawn from the reaction space through the bypass, at least one cleaning in a gas passage is ensured, since in particular this gas that flows through the bypass then enters the condensate separator .

The condensate separator can advantageously be provided for returning the condensate obtained to the reaction space, so that advantageously a return line can be provided, which opens with one of its ends into a condensate accumulation space of the separator. condensed and with its other end in the reaction space. In a similar way to that described above for the condensate, which can flow from the cooling surface of the cleaning chamber down into the reaction space, the return line also gives rise to the treatment of the condensate separator. new content of the condensate in the reaction space and thus promotes a complete conversion of the originally introduced organic waste as far as possible.

Advantageously, provision can be made for the cleaning chamber to be designed as a separate element, that is to say not only as a specific section of the reactor housing, which is provided above the reactor space. Due to the design as a separate element, a distribution of the reactor housing is possible in a lower part, which houses the reaction space, and an upper part, which houses the cleaning chamber. A thermal separation of these two parts of the reactor shell is possible and also advantageous, when the interior space of the reactor extends continuously through the reaction space and the cleaning chamber. Thermal separation avoids conduction of heat from the heated wall of the reactor space to the wall of the cleaning chamber and thus favors the achievement of two different temperature zones, such that for example the wall of the cleaning chamber It can be used as a cooling surface, on which condensate from the gas accumulates. Even if the cleaning chamber is mechanically permanently connected to the reaction space, it can be thermally insulated from the reaction space, so that the effect of the cooling surface is thus as little negatively influenced as possible and in this way, an optimal cleaning effect of the cleaning chamber is promoted.

It can advantageously be provided that the reaction space has a diameter of not more than 300 mm. In this way, from the point of view of heating from the outside, in particular from the reactor shell, a heat distribution that is as uniform as possible over the entire cross section of the reaction space is ensured, while in the case of diameters larger parts of the reaction space, it cannot be excluded that a zone forms in the center of the reaction space, which can only be heated not sufficiently intensively. The height of the reaction space can be, for example, approximately 1.5 m, and the height of the cleaning chamber for example about 0.3 m.

For the reasons mentioned above, the diameter of the reaction space can be particularly advantageously limited to a maximum value of 170 mm.

The throughput of a plant for the extraction of gas from organic waste can be advantageously increased accordingly not for example due to an increase in the reaction space, for example by an increased diameter, but due to the use of a quantity major reactors. As already mentioned, the operation of the reactor does not take place continuously, but by loads. By using a number of several reactors, the advantage of almost continuous operation of the entire plant can also be achieved in this way, in particular a production of the extracted gas as uniform as possible. This is particularly advantageous, when the gas is not fed to an accumulator, is stored intermediate and used according to demand, but has to be used directly, for example it has to be burned in a block thermal power plant (BHKW , from the German Blockheizkraftwerk). An accumulator can be provided as a buffer for possible fluctuations in gas production or fluctuations in the event of demand from the BHKW. In comparison with this, if the extracted gas is not used directly, but is basically kept in an accumulator for a longer time and possibly indefinitely, this buffer accumulator can be designed much smaller and correspondingly more economical.

For the quasi-continuous operation mentioned, the various reactors do not operate in a synchronized manner, with simultaneous interruptions for refilling or emptying or cleaning the reactors. Rather, these interruptions in reactor operation are provided displaced respectively from one reactor to another, so that the gas is expelled from the plant over a long period of time, as far as possible, in a uniform manner and thus the Post-connected components, such as the BHKW, can operate as smoothly as possible and at an optimal operating point.

An influence of the cleaning effect in the cleaning chamber can advantageously occur because the cooling surface is consciously tempered. When, as indicated above, the cooling surface is formed for example by the tube wall of the cleaning chamber, then an outer shield can extend around this wall, so that as it were, there is To a double-wall design of the cleaning chamber and by introducing liquid or gaseous media into this double-capped wall of the cleaning chamber, the temperature of the cooling surface can be controlled.

An exemplary embodiment of the invention is explained in greater detail below by means of a merely schematic representation.

In this connection, 1 generally denotes a reactor, which can be seen in a simplified way as a vertically oriented tube. A lower section of reactor 1 has a reaction space 2, which is distributed in a lower accumulation space 3 for organic waste and in an upper gas space 4, this distribution resulting automatically according to how full the space is. Reaction 2 of organic waste.

The reaction space 2 is delimited by a reactor shell 5, to which a heatable intermediate space 6 is attached radially outwardly, which is surrounded on the outside by a thermal insulation layer 7. By one end of inlet tube 8 and one end of outlet tube 9, heating gases can be guided through the interspace 6, thereby to heat the reaction space 2 from the outside, in particular by heating the reactor shell 5.

Another tube end in the reactor shell 5 is indicated in the form of a measurement tube end 10, which serves for example to detect parameters within the reaction space 2, for example gas composition, temperature or the like.

Above the reaction space 2, the reactor 1 has a cleaning chamber 11, which is designed as a tube-like extension of the reactor housing 5, but is designed as a separate element. An upper flange 12 is fixedly connected with the wall of the cleaning chamber 11, and a lower flange 14 is fixedly connected with the reactor housing 5, which surrounds the reaction space 2. Both the reactor housing 5 are thermally insulated, as well as the lower rim 14, relative to the cleaning chamber housing 11, so that the cleaning chamber wall 11 forms a tube-shaped cooling surface 15, on which gas condensate condenses, which was extracted from the organic waste and which rose from the gas space 4 of the reactor 1 upwards towards the cleaning chamber 11.

The cleaned gas is guided through a gas outlet line 16 out of the cleaning chamber 11 and enters a condensate separator 17, which has a condensation surface 18, which is cooled by means of a connection of cooling 19. Condensate from the gas condenses on this condensing surface 18 and drips from there into a condensate accumulation space 20. A return line 21 is connected to the bottom of the condensate accumulation space 20 and guides the condensate to a point not visible in the drawing, from where it accesses reaction space 2.

Apart from the mentioned gas outlet line 16, a bypass 22 is provided, through which the extracted gas cannot be removed from the cleaning chamber 11, but directly from the gas space 4. The bypass 22 opens upstream of the separator of condensate 17 in the gas outlet conduit 16. A schematically indicated butterfly valve 23 makes it possible to open or close the bypass 22 as desired.

The reactor 1 is closed upwards by means of a cover 24, which is configured as a base 25 provided below in the reactor 1, as a horizontally movable gate and allows the opening of the reactor 1 respectively by its complete free interior cross-section, so that particularly easy accessibility to the inner surfaces of the cleaning chamber 11 or the reaction space 2 is made possible and in this way a simple and rapid cleaning of the reactor 1 can be carried out. The actuators for operating the corresponding gates of the cover 24 or base 25 are respectively indicated by 26.

Claims (9)

1. Reactor (1) for gas extraction from organic waste, with a reactor shell (5) in the form of a column, with vertical orientation, which surrounds a reaction space (2), which presents a section called accumulation space (3) that can be filled with organic waste, and that presents above the accumulation space (3) a gas space (4) that collects the gas extracted from organic waste, the reaction space (2) being thermally insulated towards the outside, towards the surrounding atmosphere, and a cleaning chamber (11) being attached in an upward direction to the reaction space (2), limiting the interior space of the cleaning chamber (11) with a cooling surface (15), and a gas outlet conduit (16) that guides the extracted gas out of the reactor (1), in the cleaning chamber (11), and a gas separator being provided in the gas outlet conduit (16) condensate (17), which has a condensation surface (18) that enters the gas flow as well as a condensate accumulation space (20) located below, characterized by that a second gas pipe called bypass (22) opens into the gas space (4), which also guides the gas extracted out of the reactor (1), the bypass (22) leading into the gas outlet pipe (16). 2. Reactor according to claim 1, characterized by that between the reactor casing (5) and the thermal insulation (7) a heatable intermediate space (6) is provided. Reactor according to claim 1 or 2, characterized by that the cleaning chamber (11) is attached essentially without reduction of the free interior cross section upwards to the reaction space (2). Reactor according to one of the preceding claims, characterized by that the condensate separator (17) is arranged downstream of the point where the bypass (22) opens into the gas outlet line (16). Reactor according to one of the preceding claims, characterized by that a return line (21) is provided, which opens at one end into the condensate accumulation space (20) and at the other end into the reaction space (2). Reactor according to one of the preceding claims, characterized by that the cleaning chamber (11) has a filling opening for the organic waste to be treated. Reactor according to one of the preceding claims, characterized by that the cleaning chamber (11) is configured as a separate element, which is fixedly connected to the reactor shell (5) that surrounds the reaction space (2), and it is thermally insulated from the reactor shell (5). Reactor according to one of the preceding claims, characterized by that the reaction space (2) has a diameter of maximum 300 mm. 9. Reactor according to claim 8, characterized by that the reaction space (2) has a diameter of at most 170 mm.