JPS6157685A - Method and apparatus for producing gas from carbon-containing fuel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses one or more gasifying agents by fluidized bed and flue gasification to discharge the gasified residue from the bottom of the reactor and rise upward from the fluidized bed region. The resulting product gas is left in the upper part of the reactor after passing through a steadying zone, and the smoke dust contained in the product gas is separated to a considerable extent, and the separated smoke dust is transferred into the reactor by a feeder. The present invention relates to a method for producing gas from a carbon-containing fuel.

Various methods are known for gasifying solid fuels in fluidized bed reactors. An important problem in these processes is the separation and work-up of the flue dust coming from the fluidized bed. If post-treatment is not carried out, the efficiency will be reduced and the method will only be economical in certain environments, for example when smoke dust is used directly elsewhere.

Therefore, in all processes, the dust originating from the fluidized bed is usually worked up by providing an upper gasification stage and/or by feeding back at least some part of the dust into the fluidized bed reactor.

The characteristics of the known fluidized bed reactor (Winkler generator) are:
This is what is called upper gasification. In this reactor, the gasifying agent is injected into the free space above the fluidized bed through a ring-shaped nozzle in the reactor wall located above the fluidized bed. These gasifying agents react with the gases coming from the fluidized bed and the resulting heat is used to gasify the carbon contained in the emitted dust. (J, Anwer, F, Bogner
, to ohlevergasunB inFluidat
beLt(Winkler-Vergasung)un
ter Druck.

Brennst Jjirme, Kraft 28
(1976), 57) The amount of gasifying agent in the top gasification is limited by the temperature generated, since it is necessary to prevent the entrained ash particles from becoming liquefied or becoming doughy. Must be. If the temperature was used for coal ash 411a (ash beh
If the aviour is too high, deposits will form in the free space of the reactor and on the walls of the connected plant parts, which will have an adverse effect on the operation of the plant.

The very high gas exit temperatures resulting from top gasification throughout the stationary region further increase the gas impact on efficiency.

In the so-called HTW process (Reinische Braunkorenwerke AG), the coarse dust is fed into the reactor with the known top gasification. The gasifying agent used for the top gasification is directed into the reactor by one or several ring-shaped nozzles arranged at different heights. This solution also suffers from the same drawbacks as the traditional Winkler method.

As in the traditional Winkler process, the amount of gasifying agent that can be introduced is limited by the temperature at which the ash begins to sinter (agglomerate), and in this context the temperature peak near the wall must also be considered. Must be. A receiver portion of the ash is removed from the base of the gasification reactor, but the majority is removed from the process in the form of fly-ash via cyclones.

Other methods (Westinghouse, The
llestinghouseCoal Ga51fic
ation Process, International
nal Ga5Re5earch Conference
e June 1980; The IJ
-GasProcess, Energy Re5e
arch Vol, 4. 1 49 (1980)
), the flue dust separated in the first cyclone is fed back together with steam/recycled gas, etc. into the fluidized bed at the base of the reactor together with fresh coal, and the addition of a gasifying agent raises the temperature to such a high level that the ash agglomerates. Because it converts,
It can be removed in chunks from the convex portion of the gasification reactor.

The high temperature region created during the conversion is an integral part of the fluidized bed.

The expansion of the plant required for commercial use appears to be problematic.

The object of the invention is to eliminate the above-mentioned drawbacks and inadequacies of the known methods and to provide a process of the type mentioned at the outset which provides the best possible utilization of the carbon contained in the fuel and an effective reduction of the loading of the gas stream with solids. The purpose of the present invention is to show a method for conducting the reaction in a fluidized bed more preferably.

Furthermore, it is an object of the invention to show a method which makes it possible to utilize the energy generated during the gasification of the separated flue dust for the overall process without being subject to the limitations of known methods. Finally, the invention provides a generator with which such a method can be carried out advantageously.
).

In order to achieve the above object, the present invention provides, by a method of the type mentioned at the outset, to transfer the separated flue dust to several locations located approximately at the same height as the reactor, directly above or below the central or fluidized bed surface. blowing one or more gasifying agents into the reactor with the aid of a transport medium into the reactor in the amount necessary for the gasification of the returned flue gases (cooled lances) 1ance) to the center of the reactor up to the height of the blowing point, and the returned flue dust is converted at a temperature close to the softening point of the ash, and the exchange of material and heat is carried out between the dust gasification zone and the fluidized bed. It is characterized by being carried out between areas.

The gasifying agent for gasifying the returned flue gas is preferably fed from the top of the reactor.

According to the method of the invention, a carbon-containing solid material is converted into a combustible gas by means of a gaseous agent. After extensive work-up, the product gas has the quality of heating gas or synthesis gas.

Preferably, a solid reactive fuel with a high content of volatile components is used as the solid fuel, in particular brown coal, fresh anthracite, peat wood, etc. However, fuels with low volatile content can also be used. When using coal, the coal is previously crushed or dried and has a concentration of 12% or less, and in the case of lignite, 12% or less is used.

Oxygen, air or steam can be used as the gasifying agent, and combinations thereof can also be used.

If several gasifying agents are used, these may be fed to the reactor singly or as a mixture.

This process is usually carried out under pressure, preferably 8
It is carried out under pressure up to 0 bar. However, it is also possible to carry out this process at normal pressure.

Crude i to be gasified! ! The fuel is brought to a pressure corresponding to the operating pressure of the reactor by means of a suitable weir system, is fed continuously by a mechanical charging system, and is metered into the fluidized bed region of the reactor.

Depending on the design of the reactor, the fluidized bed has a height of approximately 1 to 3 m. The fuel to be gasified is fed into the center of the fluidized bed region, whereas the gasifying agent may be fed below the fluidized bed region. The slag produced during gasification falls from the fluidized bed and is discharged from the base of the reactor.

The temperature of the fluidized bed depends on the fuel used and is approximately 800 to 10
It is 00℃. For example, when lignite is used, the temperature is approximately 8
When using fresh reactive anthracite, the temperature is approximately 900-1000°C.

The fluidized bed is operated in such a way that about 50% of the carbon dedicated to the fuel to be gasified is converted into gas. The remaining carbon remains in the fluidized bed in the form of dust and together with the product gas cross section larger than the fluidized bed area (F −s : F m*
';:0.5) is sent to a constant chamber. As a result, the gas flow rate decreases and the large-sized smoke particles can no longer remain in suspension and fall into the fluidized bed.

A gas extraction device supplies the remaining smoke dust together with the produced gas to a drying-hot dust removal stage for separation.

The product gas further passes through a gas after-treatment zone, while the separated flue dust is fed to a thermally isolated collection tank. This collection tank has a buffer volume (bvLffervolume)
useful as. From this tank, the dust is fed back to the reactor by a transfer medium, leaving the amount in the tank at the desired level for steady-state operation. The transport medium may include steam, inert gas, process gas and CO.
2 as well as mixtures thereof can be used. These transfer gases are preferably preheated to 500-700°C. This transport medium preferably serves as a gasifying agent.

Preferred transport media are COz and superheated steam, particularly preferred is superheated steam.

According to this process, the flue gases are blown into the center of the reactor or at several locations symmetrically located at the same level as the reactor. The transfer pressure in the dust feedback pipe must be higher than the operating pressure of the reactor and sufficient to convey the returned dust to approximately the center of the reactor. The blowing nozzle is oriented in a direction in which the transport direction intersects at the center axis of the reactor or in a direction that carries the assumed circumference tangentially to the target around the center of the reactor. The height of the intersection or circumferential plane is directly above the fluidized bed surface or the same as the fluidized bed (reactor). At the same time, the amount of gasifying agent required for complete conversion of the flue gas is fed from the head of the reactor via a central cooled lancet leading to the blowing point or plane.

Oxygen or oxygen-steam mixtures are preferably used as gasifying agent.

Instead of a single cooled lancet, a ring-shaped cooled lancet can also be used.

Alternatively, the dust may be blown into the reactor via a central lancet extending into the center of the reactor. In this case, the lancet used for this purpose extending from the head of the reactor is 1
It is concentrically surrounded by individual or ring-shaped cooled gas and other agent lancets.

Preferably, the dust gasification is carried out in a confined space approximately in the center of the reactor at the level of the fluidized bed surface at a temperature higher than the temperature within the fluidized bed, and the dust gasification products are discharged from the fluidized bed; The slag obtained in softened or liquid form agglomerates and solidifies during heat transfer to the fluidized bed.

Such conversion of the dust causes temperatures to reach temperatures very close to or above the ash softening point of the fuel.

This temperature results in the agglomeration of the ash structure of the fuel particles, which becomes increasingly apparent as gasification progresses.

Due to their high specificity and size, the agglomerates that still contain ash fall below the fluidized bed area and are removed by the ash discharge means. Furthermore, this high temperature is essential for the rapid and complete conversion of the returned and generated flue dust.

Due to the gas flow directed onto the surface and the lower region of the fluidized bed, a strong heat and mass exchange is ensured between the gasification products of the dust gasification and the fluidized bed. As a result of the known good heat transfer in fluidized beds, this heat is quickly absorbed throughout the fluidized bed. The result of this is a correspondingly reduced demand for oxygen and coal to maintain the reaction temperature required for the fluidized bed. Furthermore, the resulting high-temperature region caused by the flue gas is limited in such a way that the wall section is only exposed to relatively low fluidized bed temperatures. Therefore, there is no risk of exposing the reaction walls to high temperatures or of adhesion of ash particles.

Transfer of heat to the fluidized bed further ensures that the temperature falling in the stationary region located above the fluidized bed is not significantly increased by the hot product gases produced during flue gasification. As a result, the product gas outlet temperature remains low compared to known processes (fluidized bed with top gasification).

A good mass exchange also guarantees the direct utilization of the gas components COz and Hz2O as secondary gasifiers or relaxation agents in the fluidized bed during flue gasification.

Control of the dust gasification is carried out by very simple methods: temperature measurements in the fluidized bed and stationary chamber and measurement of the carbon content in the dust. A particularly important measure of dust gasification depends on the continuous determination of the amount of dust introduced, for example its carbon content, by means of radiometer measurements. In this case, the total gasification is regulated by measuring the temperature of the stationary chamber. Measuring the actual temperature in the fluidized bed and in the stationary chamber directly exposes irregularities in the early stages, e.g. dust transport, as well as temperature differences between the two, so this is the right time! tJ1 may be noted. The high mass and heat capacity of a fluidized bed prevents the appearance of dangerous oxygen and heat under any empty operating conditions.
k-throughs).

The gasifying agent used in the process may be conveniently preheated to reduce oxygen and fuel consumption. This is done by transferring considerable heat contained in the production, for example by means of a heat exchanger.

The process according to the invention provides many advantages.

Gasification of the returned flue dust can be carried out at temperatures in the range of the softening point of the ash and above.

The ash agglomerates, falls out of the fluidized bed during heat transfer, solidifies, and is then discharged from the base of the reactor. Due to high temperature,
The dust gasification efficiency increases. The central feed of the dust gasification agent allows the dust gasification to take place in a confined space in the center of the reactor. The reactor walls are therefore protected from excessive heat. Furthermore, carrying out the dust gasification directly above or below the fluidized bed allows for the exchange of materials and heat with the fluidized bed. For example, using COz or steam as a transport medium allows dust to be fed back without intermediate cooling. Finally, simple control of the process is possible with the aid of the measured temperature values.

In particular, the temperature within the reactor flow pressure and the temperature of the stationary chamber as well as the carbon content in the returned flue dust are used as variables for regulating the flue gasification.

The pressure-resistant reactor for carrying out the process consists of an ash outlet located at the base of the reactor; a fluidized bed area at the bottom and a stationary area with a large cross section at the top, a transition from the fluidized bed area to the stationary area; The reactor housing has a dust gasification area at the top and is protected against high temperatures by a refractory lining; the reactor head is connected to a drying-hot dust removal stage that opens into a dust collection tank. a product gas outlet located in at least one fluidized bed region; a fuel inlet in at least one fluidized bed region and a gasifier inlet in the fluidized bed region. The reactor consists of one or several main dust blowing devices located directly above or below the surface of the fluidized bed and located at the same height; a dust collection connected to the blowing devices by feed pipes. It is characterized by having one or several cooled lancets for introducing the flue gasifier which protrude centrally from the reactor head to the level of the tank and blowing device into the reactor center.

Due to the ease of operation and the availability of one run, FiT ii:...
r) is recommended. The generator 49 according to the invention is characterized by a high degree of operational reliability as well as a simple control system 4111, as will be described later, and therefore a high degree of availability can be expected.

In particular, this applies to the feedhack method and the fume dust transfer method according to the invention in the hot zone in the center of the reactor.

Separation of the smoke dust contained in the produced gas is carried out in a drying/high-temperature dust removal stage which is disposed inside or outside the reactor and has an open gas outlet vibe connected to the head of the reactor. The dust removal stage is preferably formed by a cyclone, which when located outside the reactor is preferably thermally isolated. However, other suitable devices may also be used.

The separator is connected to a thermally isolated collection tank,
Separated high-temperature smoke dust is collected here. The collection tank is connected to the reactor by a feedback pipe for feeding back the smoke and dust. by connecting the feed pipe for the gas transport medium with one or several devices for controlling and metering the amount of gas transport medium and, if desired, the composition of the mixture when gas mixtures are used;
The amount of returned flue dust and the temperature within the feedback system can be determined.

The dust feedback is preferably placed near the surface of the fluidized bed. However, this feedback can also take place in other areas of the fluidized bed or just above the surface of the fluidized bed.

The blowing devices for returning the flue gas are arranged symmetrically in the reactor at the same height, such that the direction of transport intersects the middle axis of the reactor. Alternatively, the blowing device may be arranged symmetrically in a direction that tangentially conveys the assumed circumference around the reactor central axis. However, the diameter of this circumference must be small compared to the diameter of the reactor space.

A lancet for supplying gas projects from the reactor head into the reactor to approximately the same level as the injection point. The lancet is placed in the center of the reactor and is cooled. The gasifying agents required for gasification are introduced inside the lancet individually or together. The lancet opens into a suitable nozzle system. Like the two-substance nozzle, an I-substance nozzle is also used; a one-substance nozzle is used when air and steam are used as gasifying agents, and a two-substance nozzle is used when oxygen and steam are used.

It is also possible to install a plurality of lancets in the form of a bundle or a ring instead of a single lancet. In this case too, the individual lance throats are cooled.

If several gasifying agents are used, these are fed through different lancets in the form of bundles or rings.

If the feedback is carried out centrally through the reactor central axis, the blowing device is designed as a lancet extending from the reactor head to the dust gasification area, and this lancet has one lancet for introducing the gasifying agent. or concentrically surrounded by several cooled lancets.

It is advantageous to adapt the gasifying agent introduced via the central cooled lancet to the amount of recycled dust and the fuel content. Here, the use of the gasifying agent as a transport medium for the dust may also be taken into account. For this purpose, there are metering devices that are controlled by a central control unit. For example, the carbon content of the smoke dust may be determined by radiographic measurements performed during the separation operation in the collection tank or prior to feedback.

Other parameters may be considered for the central control of the flue gasification, such as the temperature of the fluidized bed and the stationary chamber, which can be measured by suitable thermometers;
There is also an amount of gasifying agent introduced with the gaseous transport medium for dust gasification.

FIG. 1 is a schematic cross-sectional view of an embodiment of a reactor according to the invention, which is suitable for the gasification of lignite or highly volatile anthracite.

The reactor shown in FIG. 1 consists of a vessel which encloses the entire reaction space in the form of a rotating hollow body with a cylindrical region and a conical region, in the bottom of which a fluidized bed gasification region A and in the upper part. There is a steady state region B and a dust gasification region C. The reactor base 1 opens into a cylindrical pipe shed connected to an ash discharge system 2.

The reaction chamber is closed off in the reactor head 10, for example by an arched cover. The reactor walls are protected from high temperatures by a suitable refractory lining.

The fluidized bed A at the bottom of the reactor is 1-3 m depending on the reactor design.
It has a height of The fuel population 6 is located in the center of the fluidized bed area. Although the fuel is supplied by a transfer screw, other arrangements for supplying fuel may be provided. A filling valve is provided to counteract the reaction pressure.

Below the fuel population 6, a population pipe 7 for the gasifying agent
are distributed around the periphery and arranged in a ring shape. This part of the reactor, including the fluidized bed area A, has an upwardly widening, in particular conical, internal cross section. The shape to this area is similar to the top end and bottom end sections.
The granular fuel with a constant particle size distribution and the gas produced during gasification are selected so as to maintain a fluid state.

The reactor is closed and designed to allow gas production under increasing internal pressure. However, it can be operated without increased pressure. If only the latter is considered, the filling valve for the fuel port 6 may be omitted or replaced with another device if necessary.

The feed pipe 7 for the gasifying agent is for one substance and/or
Alternatively, it is designed as a two-substance nozzle system, for example as a one-nasal nozzle when air and steam are used as gasifying agents, and as a two-nasal nozzle when oxygen and steam are used.

The upper part of the reactor contains stationary chamber B. Its cross section F is larger than the cross section of the fluidized bed area A, with Fws:Fa++''1:2.

The reactor head 10 is provided with a gas outlet 3, which in this embodiment is arranged on the side and is dedicated to a drying-hot dust removal stage 4, generally a cyclone. At this stage, the smoke and dust are separated. The product gas flows via pipe 3'' to the usual gas after-treatment process.

The separated smoke dust is transferred from the smoke dust removal stage to the collection tank 5 and collected. This collection tank contains a metering device for determining the carbon content of the smoke dust 15, for example a radiometer measuring device consisting of a radiator and a receiver. This measuring device is connected by a line to a central control unit 16 for regulating the flue gasification.

In steady state operation, dust removal from the collection tank 5 is controlled to maintain the desired level. This level can be measured, for example, by radiometer level measuring device 18.
It can be adjusted by

A pipe 11 for feeding the dust from the collection tank 5 has a metering device 12 for the dust and a feed pipe 13 for the gaseous transport medium connected to the metering device 12 (Ii
ff may be left.

The dust is fed back from the collection tank 5 to the reactor via pipe 11. The amount of smoke dust returned is determined by a measuring device 12.
It can be adjusted by Gas is supplied as transport medium, preferably from a steam pipe 13I. The adjustment of the metering device 12 takes place by means of an adjustment unit 16.

The amount of transport medium to be used depends on the amount of dust to be returned.

The feedback pipe 11 is guided into the reactor by several dust inlet systems distributed symmetrically at the same height around the reactor. These dust injection systems 8 may each be directed toward the reactor center, or may be directed tangentially around an assumed circumference around the reactor center. The blowing nozzle 8 may terminate in the reactor wall or may project into the reactor, preferably into the reactor.

A cooled lancet 9, or alternatively a bundle of cooled lancets, projects centrally from the reactor head 10 into the reactor center to the level of the blowing point 8. Through this lancet, gasifying agents, such as oxygen and steam, are introduced together or separately by means of a suitable nozzle system at the blowing point 8. This makes it possible to carry out the post-gasification of the carbon contained in the dust in a very limited area C at the level of the fluidized bed surface in the center of the reactor at a temperature not lower than the melting point of the ash. All of the solid content is softened,
It melts, agglomerates and, because of its large agglomerates, falls through the fluidized bed area A and is then discharged in the form of ash lumps.

In the fluidized bed region A and the steady state region B, gauges 14 are installed for measuring the temperature, and these gauges 14 are connected to a regulating unit) 16.

The supply of gasifying agent to the post-gasification zone C through the lancet 9 is controlled by the EFR node unit 16 using a metering device I7.

To protect the central lucent 9 from the high temperatures inside the reactor,
The lancet is cooled. Cooling typically involves cooling fluid,
This is preferably carried out by means of a double casing pipe through which water flows, inside which the actual gas and other agent pipes extend. Double casing pipes surround several pipes for individual gasifiers. When using ring-shaped lancets, each lancet is designed accordingly.

The following example shows characteristic data when lignite was used in the reactor.

Example Reactor pressure 15 bar Reactor temperature (gas outlet) 1100°C Consumed gasifier steam 0.38 Ng/kg Coal-af crude gas analysis CO48,8% (volume) (dry) H232,0 CH, 3,0〃 c o215.4 HzS O,1〃 N2 0.7〃C-conversion
96% Gasification efficiency 78.5%

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the reaction apparatus of the present invention. 1...Reaction base, 4...Fume dust removal system. 5... Collection tank, 6... Fuel inlet, 10...
Reactor head. A... Fluidized bed gasification region, B... Steady state region. C... Dust gasification area

Claims (16)

[Claims] (1) Fluidized bed and flue gasification using one or several gasifying agents to discharge the gasification residue from the bottom of the reactor and direct the product gas rising upward from the fluidized bed region to the steady state region. In the method of producing gas from carbon-containing fuel by separating the smoke dust contained in the produced gas to a considerable extent by leaving it in the upper part of the reactor after passing through it, and feeding the separated smoke dust back to the reactor, the separated smoke dust is The dust is blown into the reactor with the help of a transport medium at several locations placed approximately at the same height as the reactor, either in the center of the reactor or directly above or below the surface of the fluidized bed. The amount of one or more gasifying agents required for gasification is introduced into the center of the reactor by one or several cooled lancers, passing through the center of the reactor up to the height of the gas injection point. and then converting the returned flue dust at a temperature close to the softening point of the ash, and exchanging materials and heat between the flue gasification zone and the fluidized bed gasification zone. How to manufacture. (2) A process according to claim 1, wherein the gasification is carried out at a reactor pressure of 1 to 80 bar. (3) The method according to claim 1, in which a gasifying agent for gasifying returned smoke dust is supplied from the top to the reactor. (4) The method according to claim 1, wherein the gasifying agent is preheated. (5) Separated dust is collected in a dust collection tank and fed to the metered reactor in such a way that in steady operation the amount remaining in the collection tank is maintained at the desired level. The method described in section. (6) Claim 1, in which the smoke is blown into the reactor at several positions symmetrically arranged at the same height as the reactor so as to transport the smoke dust in a direction crossing the center axis of the reactor. the method of. (7) A patent claim in which smoke dust is blown into the reactor at several positions symmetrically arranged at the same height as the reactor so as to transport the smoke dust in a direction that tangentially hits the assumed circumference around the reactor's central axis. The method described in item 1. (8) The method according to claim 1, wherein the smoke dust is blown into the reactor through a central lancet. (9) The gasification of dust is carried out in a confined space approximately in the center of the reactor at the level of the surface of the fluidized bed, and the gasification of dust is carried out at a temperature higher than the temperature in the fluidized bed, and the dust gasification product is 2. A method according to claim 1, wherein the slag is discharged into a fluidized bed and the slag becomes a soft or liquid mass and solidifies during the transfer of heat to the fluidized bed. (10) Claim 1 using the carbon content in the returned flue in the fluidized bed and stationary chamber as well as using the temperature in the reactor as a variable to adjust the flue gasification.
The method described in section. (11) an ash outlet located at the base (1) of the reactor;
with a fluidized bed area (A) at the bottom and a stationary area with a large cross section at the top (B), a dust gasification area at the transition from the fluidized bed area to the stationary area (C), with a refractory lining. a reactor housing protected against high temperatures by a product gas outlet (3) located at the reactor head connected to a drying-hot dust removal stage (4) opening into a dust collection tank; In a pressure-resistant reactor consisting of a fuel inlet (6) in at least one fluidized bed region (A) and a gasifying agent inlet (7) in the fluidized bed region, provided directly above or directly below the surface of the fluidized bed,
One main or several dust blowing devices (8) arranged at the same level, a dust collection tank (5) connected to the blowing devices by means of a feed pipe (11) and the level of the blowing devices 1 for introducing the flue gasifier which protrudes from the reactor head (10) to the center of the reactor central part.
A pressure-resistant reactor characterized by being equipped with one or several cooled lancets. (12) The reactor according to claim 11, wherein the gasifying agent inlet (7) has a shape of a nozzle type for supplying two types of materials. (13) A pipe (11) for returning the dust from the collection tank (5) is provided together with a metering device (12) for the dust and a feed pipe (13) for conveying the gas to the central part. A reactor according to scope item 11. (14) Blow-in device for feeding back smoke and dust (
8) is arranged symmetrically at the same height as the reactor so as to carry it in a direction transverse to the reactor center axis.
Reactor described in section. (15) Blow-in device for feeding back smoke and dust (
12. The reactor according to claim 11, wherein the reactors 8) are arranged at the same height of the reactor so as to carry the smoke dust in a direction tangentially perpendicular to the circumference assumed around the center axis of the reactor. (16) The main blowing device (8) is designed as a lancet projecting from the reactor head into the flue gasification zone (C), one or more lancets for introducing the gasifying agent. 12. Reactor according to claim 11, characterized in that it is concentrically surrounded by several cooled lancets (9).