NO151530B - PROCEDURE FOR COMBINED USE OF WASTE AND PREPARATION OF WATER AND APPARATUS FOR EXECUTION OF THE PROCEDURE - Google Patents

Description

The invention relates to a method by combined

utilization of rubbish and processing of waste water, where the waste water is mixed with at least part of the ground rubbish, a separation into organic and inorganic components is carried out, the waste water flow with the dissolved and suspended components of the rubbish is led through a two-stage filter which is carried against

electricity and which consists of inactive coal and activated coal, solid waste or a part of the filter carbon saturated with dirt is burned by pyrolysis in a first reactor of a multi-reactor mile with the extraction of heat and fuel gas, the main part of the carbon saturated with dirt is treated by thermolysis in another reactor for regeneration, whereby the dirt that adheres to the coal filter, is thermally decomposed and forms coal and low-temperature coking gases, the regenerated filter coal from the second reactor is returned to the filtration zone for the dewater, possibly after the filter coal has been activated, and the obtained low-temperature coking

gases are utilized in terms of energy.

In German official document no. 2558703, a method is described

written for combined utilization of garbage and wastewater treatment. This method is based on a relatively simple and economical technique, where 1. the wastewater serves as a means of transport for the garbage and also to separate the garbage into inorganic and organic components, 2. the wastewater that has been contaminated with the garbage is purified by mechanical and adsorptive filtration by use of normal coal and activated carbon,

3. e,n part of the rubbish or of the dirt-laden asset

coal is combusted and thereby emits, in addition to a combustion gas, the heat required for thermolysis, and 4. the main part of the dirt-laden filter coal is thermally split in a thermolysis reactor, whereby the filter coal is regenerated and, in addition, new coal and coking gas are extracted.

Although the above-mentioned method offers a number of advantages, it is still desired to improve this in order to achieve an optimal utilization of the energy. It is also necessary to eliminate disadvantages and difficulties that arise during the execution of the method. It can thus be done by using coal or activated carbon produced by the method according to the above-mentioned German publication No. 2558703, rubbing of the coal and thus loss of coal, clogging of the filtration towers and also contamination of the service water obtained.

The invention aims to improve the energy balance in this method by optimal utilization of all energy sources and to ensure a disturbance-free process, and this is achieved according to the invention in particular by a conscious choice of the reaction conditions in the multi-reactor mile and a corresponding treatment or processing of the products from the multi-reactor mile.

This task according to the invention is solved by the method-specific features that the pyrolysis process in the first reactor is carried out in the presence of 30-90% of the amount of oxygen that is stoichiometrically necessary for complete combustion, and at a temperature that essentially does not exceed 800°C, that the thermolysis process in the second reactor is carried out in an oxygen-free atmosphere, and that at least part of what was produced in the second reactor or regenerated coal is pelletized.

At least part of the fuel formed - or coking gas containing long-chain hydrocarbons can, optionally using the heat content of the gas with the aid of a heat exchanger, be split in a thermal cracking device into short-chain hydrocarbons.

The multi-reactor mile used according to the invention can comprise several reactors of the first-mentioned and of the second-mentioned type which are preferably made up of continuously operated rotary tube furnaces. The first reactor is then preferably arranged in the lower part of the multi-reactor mile, while the second reactor is preferably arranged in the upper part of the mile above, but in the immediate vicinity of the first reactor, so that the second reactor can be heated by the heat from the first reactor by convection heating.

An apparatus for carrying out the present method comprises a wastewater supply with settling basin, coarse and fine filter elements filled with coal or activated carbon and also grinding devices for garbage, a multi-reactor mile with at least one thermolysis reactor and at least one pyrolysis reactor which are arranged immediately close to each other, and pre-drying devices for garbage respectively. filter coal, and the device is characterized by the fact that a pelletizing device for pelletizing the coal from the thermolysis reactor and grinding devices are connected after the thermolysis reactor.

The first reactor is used for pyrolysis of rubbish or

part of the coal that is saturated with dirt, while the main part of the coal that is saturated with dirt is thermolyzed in the

other reactor. In addition, the first reactor of the multi-reactor mile can periodically be coated with saturated normal coal or, active

coal, followed by a combustion of the coal which is contaminated

• with heavy metals, and of the removal of the heavy metals together with

ash from the reactor. It is also possible to cover the thermolysis reactor (the second reactor) with solid, preferably organic waste or to mix rubbish into the ovenware.

The present method is distinguished by a particularly advantageous combination of different process steps which enables maximum utilization of the energy for the processes that take place in the multi-reactor mile, whereby the heat generation during the pyrolysis or the combustion is regulated by a measured supply of oxygen, and the remaining energy is obtained in the form of a relatively hydrocarbon-rich fuel gas. With the help of the present method, depending on the composition of the rubbish, it may be possible to operate the combined plant for utilization of rubbish and purification of waste water without having to supply energy from outside and also to extract additional energy.

Due to the selected, particularly favorable conditions in the multi-reactor mill, a filter coal with good absorption properties is obtained during the thermolysis and, moreover, a coking gas that is particularly highly enriched with hydrocarbons. In the special processing of fuel or the coking gases that come out of the multi-reactor mile, storable energy is extracted, whereby the heat content of the gases can be used by means of heat exchange in the plant for carrying out the present method for pre-drying, heating the backwash water or for the thermolysis step. By purposeful treatment of the filter coal that is removed from the multi-reactor mill, difficulties in carrying out the method can also be avoided. According to the invention, the aim is to pelletize • the regenerated filter carbon used in the coarse filter, i.e. to transfer this to a compact form with the desired particle size, whereby a rubbing of the carbon and the consequent soiling of the water obtained and also blockages of filter elements filled with filter carbon can be avoided, or to produce a filter material with a particularly large surface, i.e. with a high adsorption

ability, from the charcoal used in the fine filter to be activated,

by pre-processing this. These procedure steps are explained in more detail below.

The pyrolysis is carried out according to the invention at a temperature

which must not be significantly higher than 800°C. A particularly preferred temperature range is between 500 and 800°C. It is also sometimes preferred to use temperatures in the range of 300-400°C to avoid evaporation of certain heavy metals.

Oxygen is supplied to the first reactor in a sub-stoichiometric ratio. The oxygen is thereby dosed so that the pyrolysis is maintained, but so that the temperature is regulated so that it essentially does not exceed 800°C. The added amount of oxygen amounts to

30-90% of the stoichiometrically required amount of oxygen, preferably 50-80%. The amount of oxygen then depends on the composition of the kiln material to be burned, and also on its degree of moisture.

The fuel gas produced by pyrolysis in the first reactor is relatively rich in hydrocarbons due to the regulated heat development. The coking gas which is formed in the second reactor by the thermolysis of the soiled filter coal or by the thermolysis of the solid waste is particularly rich in long-chain hydrocarbons.

The formed fuel or coking gas can be used as an additional external energy source for the thermolysis process or as fuel for a separate boiler, a device for burning gases, preferably a combustion engine, or a similar device.

It is also possible to treat fuel or the low-temperature coking gas in a cracking device to split long-chain hydrocarbons into short-chain molecules which can in turn be used directly in combustion engines, turbines and similar devices, or which, after they have been liquefied, constitute an easily storable energy source.

It is advantageous to liquefy the gases coming from the high-temperature zone, by cooling them to a sufficient extent, whereby possibly a separation into liquid nitrogen and into a liquid, combustible, nitrogen-free gas, e.g. a methane gas, then can be carried out.

According to a preferred embodiment of a cracking

device that works with a high degree of efficiency is carried out

the splitting of the long-chain hydrocarbons into short-chain hydrocarbons in an oxygen-poor high-temperature zone at a temperature

of at least 130p°C. The cracking of the long-chain hydrocarbons can

also carried out in the aforementioned apparatus under the exclusion of oxygen,

so that no combustion or oxidation of the obtained gas takes place.

The aforementioned high-temperature zone is created in the cracking apparatus

in that combustible materials, "such as wood or coal, e.g. filter coal, are filled in a vertical container and burned at the lower end of the container by blowing in a measured amount of oxygen, and by the fuel gas being led downwards through the apparatus and oxygen-

the amount is dosed so that a controlled combustion of the materials and also the formation of the desired temperature is ensured.

The combustible materials are introduced in a sufficient quantity into the apparatus, and more precisely so that during the operation of this part of these materials has a relatively lower temperature, as the mentioned fuel or low-temperature coking gases are led over or through the materials at a low temperature, so that the solid and liquid small parts that are carried with the off-gases remain adherent .. and also burn as soon as the said materials are in the high-temperature zone.

It is advantageous to lead the formed exhaust gases through a heat exchanger, whereby the heat energy is transferred from the exhaust gases to the heat exchanger medium. The heat extracted from the exhaust gas can be used to dry solid waste and/or filter coal in advance

is saturated with dirt, or it may serve to support the pyrolysis or thermolysis steps that take place in the multireactor mile. In addition, the heat extracted from the exhaust gas, via a second heat exchanger, can be used to heat the water used for backwashing the saturated activated carbon, in order to facilitate the desorption of the

unfiltered materials adhering to the activated carbon. It is also advantageous to pass the exhaust gas through a carbon filter to remove particulate contaminants.

According to the invention, the filter coal produced in the second reactor can be specially treated to avoid difficulties that may arise due to abrasion of the coal during the course of the process. For this purpose, the regenerated coal, which is relatively soft and has a very different particle size, is pelletized using one of the usual methods, possibly using a binder. It is then necessary to separate the finely divided coal particles and the coal dust, e.g. using a sieve, and then feeding these to the pelletizing apparatus and mixing these with the sieve residue, i.e. with the coarser coal particles, in the form of pellets. This mixture is then used to fill the coarse filter elements (1st filtering section).

For the production of activated carbon, according to the invention, the regenerated carbon is pre-treated so that it acquires a sufficient hardness and a fairly uniform particle size.

For this purpose, the coal obtained in the second reactor is finely ground and mixed, e.g. with tar or pitch in a ratio of 10:1-5:1. This mixture of coal/tar or the pitch is then pressed under high pressure, preferably a pressure of 1000-2000 kp/cm 2 and at temperatures just above the softening point of the tar or pitch in question. The obtained mixture of coal/tar is then ground down, respectively. pitch to the desired particle size. This can preferably be carried out with the help of a roller chair to

keep the financial share as low as possible. Of course, other painting facilities, such as e.g. impact mills, are used.

The particle size to which the filter charcoal is ground down corrects

according to the intended purpose of use. Activated carbon used for the purification of liquids should therefore preferably have a particle size of 0.5-1.5 mm. The activated carbon used for the gas purification should preferably have a particle size of 2-3 mm.

If the coal that will later be activated is used exclusively for the purification of gases, the following procedure is applicable: The coal from the second reactor is finely ground and mixed with tar or pitch in a ratio of 10:1 - 5:1 and then pressed under high pressure, preferably a pressure of 1000 kp/cm 2 , and at temperatures that are just above the softening point of the tar or the pitch used, using string presses directly to form pieces of the desired size.

The thus obtained splinter granules or Molded pieces of the desired size can then be activated with hot steam or with chemicals in an activation apparatus using a method common in the relevant art. This results in an activated carbon with a particularly high adsorption capacity. This activated carbon is preferably pelletized in a pelletizing device.

Advantageous embodiments of the invention are shown in the drawings. From the drawings show

Fig. 1 schematically a flowchart for the present method for combined utilization of garbage and purification of wastewater, Fig. 2a and 2b a combined method according to the invention for utilization of garbage and purification of wastewater, Fig. 3 a flowchart for the production, application and regeneration of normal' and activated filter carbon, according to the invention, Fig. 4 a cross-section, seen from the front, of the multi-reactor mill according to the invention, and Fig. 5 a side view in cross-section of the multi-reactor mill shown in Fig. 4 taken along the line 5-5.

In Fig. 6 is a cracking device for treating fuel or the low temperature coking gas shown.

Fig. 1 shows a flow chart for the material flow during the processing of solid and liquid waste in a waste processing and wastewater treatment plant 102 according to the invention. This plant comprises a multi-reactor mill 104. The solid waste to be processed and which may include, among other things, food waste, paper, plaster, oil and tar residues, old rubber tyres, wood, glass, ash and similar materials are pre-treated by separation on magnetic tape, splitting and flotation in the raw water so that the waste essentially only consists of organic components for further processing. in the multi-reactor mile 104, the solid waste is pyrolysed in a first reactor in an oxygen-poor atmosphere, producing heat, fuel gas and ash.

Awannet can include both municipal waste water and industrial waste water.

A multi-stage charcoal filter 106 is used to clean the waste water, as follows

that this can at least be used for industrial purposes. The charcoal filter 106 preferably consists of a two-stage filter consisting of a coarse filter and a fine filter. The filter carbon for the coarse filter is periodically regenerated in mile 104 together with the small particles and the sludge that adheres to the carbon, i.e. it is subjected to a heat treatment while excluding oxygen. Due to the newly mined and regenerated coal, coal losses are compensated.

Figs. 2a and 2b and supplemented by Fig. 3 show an overview of the treatment method in the waste utilization and sewage treatment plant 102. An inlet channel 108 for waste water leads waste water to the coarse filter 114 via a settling basin 110 and a sieve 112. Then follows the final cleaning of the water in the fine filter 116, and the water leaves the facility via the outlet channel 118.

The coarse filter 114 consists of a number of coarse filter elements 120 which can be removed from the coarse filter for regeneration by raising and lowering respectively. which can be returned to the coarse filter. Each filter element 120 is filled with normal filter carbon of a suitable particle size, preferably with pelletised filter carbon. The coarse filter elements are moved during use of the device in countercurrent to the flow direction of the waste water from the end of the filter 122 to the beginning of the filter 124.

The fine filter 116 likewise consists of a number of fine filter elements 126 which are likewise moved step by step in countercurrent to the wastewater's flow direction from the lower end 128 to the upper end 130. The fine filter can be cleaned by backwashing, possibly in backwashing devices 134 intended for this purpose. The backwash water is preferably taken directly from the outlet channel 118 and can be stored for a certain time in the reservoir 136 which is provided with heating coils 138. The water that has been contaminated due to the backwash flows through the return line 140 back to the inlet 108 for the unwashed water. For the processing of the rubbish, the solid rubbish is filled in a silo 160 where a first treatment or separation of the rubbish takes place with the help of a magnetic belt 162, a conveyor belt 166 and paint-down rollers 164.

In the settling basin 110, the materials with a density above 1 are separated and removed with the help of the beaker transport unit 168. A series of air nozzles 170 ensure a thorough mixing of waste water and rubbish which facilitates the separation of this into organic and inorganic components. A transport device 132 transports floating organic materials to the two storage chambers 172 for the multi-reactor mile 104. In addition, additional garbage can be continuously introduced into the storage chambers via the conveyor belts 174.

The multi-reactor mile 104, in which simultaneously in different reactors the pyrolysis and thermolysis of garbage and/or filter coal which is loaded with dirt, takes place, is shown in Fig. 4 and 5. The reactor 178 is used for combustion or pyrolysis of rubbish and/or filter coal loaded with dirt. In the reactor 186, the thermolysis of saturated filter coal finds resp. rubbish place.

A housing 222 delimits the interior 190 of the shaft. Shafts 224 are stored on bearings 226 and are driven by a drive device 228 with a motor 23 0. The furnace goods are filled respectively. is removed from the reactors via openings 232 for filling and emptying with a door 234 and a door 236 with a further device for closing the doors. The doors 234 and 236 have joints 262. In addition, the reactors 178 are provided with an air inlet 238, an outlet 240 for fuel gas and convex sieves 242. The reactor 178 is also connected to a gas line 184 which is provided with a non-return valve 246, and also with a cracking device 192, a washing device 196, an incinerator 202, a generator 204 and a branch line 248 with a valve 250.

A collection container 252 for rubbish is provided with a shut-off plate 254 which separates a collection space 256. At the lower end of the collection space 256 is a plate 258 with a joint and with a thermal insulation 260.

A collection space 264 which can be opened downwards is delimited by

a plate 266 which is provided with a joint. After the thermolysis or pyrolysis, the solid materials are removed from the reactors and transferred to funnel-shaped containers 268 and 270. These are provided

with heat exchange coils 272 and with a sliding hatch 274. Under the containers 268, 270 a conveyor belt 276 is arranged.

In addition, air can be introduced into the interior 190 of the shaft via an inlet line 278 with a valve 280. A gas line 282 with a valve 284 is arranged above the thermolysis reactor 186. In addition, the thermolysis reactor 186 is provided with a heat transfer line 288.

The coal formed in the reactor 186 is sorted by means of

a sieve 290 (Fig. 3). Larger coal particles can be used directly in the coarse filter 114. The sieved smaller coal particles and the coal dust are formed into pellets of the desired particle size in a pelletizing device 292 (Fig. 3). These pellets are also used to fill the coarse filter elements 120. For the production of activated carbon, the filter carbon coming from the reactor 186 is pretreated, i.e. it is finely ground in a malean egg 295, and it is then optionally pelletized and again ground to a desired grain size. The activation is carried out in an activation device 294 as appropriate

a further pelletizer 296 is attached. The activated carbon obtained is used to fill the fine filter 116 or it can be used for commercial purposes.

The above explanations clearly indicate that with the help of the waste utilization/wastewater treatment plant 102 it is possible to fully produce the normal coal and activated coal that is necessary to clean the waste water, and to regenerate these.

Fig. 6 shows a cracking device 192 which consists of

of a vertical, double-walled container 298 in which an inner container 300 is suspended from the upper end 302 of an outer, supporting container 304. The inner container has an upper end 306 which is covered with a shut-off plate 308 which can be opened. The lower end of the inner container 300 has a constriction 310 and a sieve 312. Below this, a further sieve 316 is located.

A circular air supply line 318 surrounds the constriction 310. This air supply line 318 has a series of air nozzles 320 which are used to blow combustion air or oxygen into the interior of the container 300 immediately above the sieve 312. Through the line 184 the gas to be split is led into the upper part of the internal container 300, and it ends in a downward-facing cap 322. The interior of the container 300 is filled with relatively large particles of a combustible material, preferably wood, and more specifically so that the combustible material fills the main part of the internal space between the sieve 312 and the gas discharge cap 322. The wood located immediately above the sieve 312 is ignited, and via the air nozzles 320 oxygen is introduced for combustion so that a high-temperature zone is formed which, however, only occupies a relatively small area above the sieve, while the rest of the combustible material remains relatively cold in the container's 300 internal. After the desired temperature has been reached in the high-temperature zone, fuel or the low-temperature coking gas into the cracking apparatus via the line 184 and the hood 322. In addition, the fan 324 is started so that a weak vacuum is formed in the outer container 304, whereby the gas that is led in via the hood 322 is drawn off through the cold zone of combustible material and high-temperature the zone in the annular space 326 between the containers via the suction line 328 and the fan 324.

The obtained split gas can be supplied directly to a combustion engine 202 or liquefied in the condensing plant 206 and possibly separated into a gas preferably on a methane basis and in liquid nitrogen.

At time intervals, new combustible material is supplied to the cracking device via the cover 308. This supply can also be carried out continuously.

Claims (3)

1. Procedure for combined utilization of rubbish and processing of waste water, where the waste water is mixed with at least part of the ground rubbish, a separation into organic and inorganic components is carried out, the waste water flow with the dissolved and suspended components of the rubbish is led through a two -stage filter which is carried in countercurrent and which consists of inactive carbon and active carbon, solid waste or a part of the filter carbon saturated with dirt is burned by pyrolysis in a first reactor of a multi-reactor mile with the extraction of heat and fuel gas, the main part of the carbon saturated with dirt is treated by thermolysis in another reactor for regeneration, whereby the dirt that adheres to the charcoal filter, is thermally decomposed and forms charcoal and low-temperature coking gases, the regenerated filter coal from the second reactor is returned to the filtration zone for dewatering, possibly after the filter coal has been activated, and the obtained low-temperature coking gases are utilized in terms of energy, characterized in that the pyrolysis process in the first reactor is carried out in the presence of 30-90% of the amount of oxygen that is stoichiometrically necessary for complete combustion, and at a temperature that essentially does not exceed 800°C, that the thermolysis process in the second reactor is carried out in an oxygen-free atmosphere, and that at least part of what was produced in the second reactor or regenerated coal is pelletized. 2. Method according to claim 1, characterized in that the solid waste is incinerated in the first reactor of the multi-reactor mile at 500-800°C. 3. Method according to claim 1, characterized in that from the filter coal or the regenerated coal that is extracted in the second reactor is separated from the pieces of coal that are smaller than a desired piece size, and the coal dust and the separated coal are pelletized into coal pellets, after which the pelletized coal is optionally mixed with the previously separated, coarse pieces of coal. 4_ Method according to claim 3 , characterized in that the pelletized coal and/or the sorted, coarser pieces of coal are used as filter coal in the first filtration section. 5. Method according to claim 1, characterized in that the coal produced in the second reactor of the multi-reactor mill is activated after grinding down and possibly pelletised. ^" Method according to claim <5,> characterized in that the newly extracted or regenerated filter coal is finely ground before it is activated and mixed with tar or pitch in a ratio of 10:1-5:1, and that the resulting mixture is pressed using high pressure and at temperatures slightly higher than the softening point of the binder used, and then ground down to the desired particle size. 7. Method according to claim 5, characterized in that the newly mined or regenerated filter coal is finely ground before it is activated and mixed with tar or pitch in a ratio of 10 :1 - 5:1, and that the mixture obtained is pressed directly into shaped pieces of the desired size using bar presses at high pressure and at temperatures slightly higher than the softening point of the binder used. 8. Apparatus for carrying out the method according to claim 1, comprising a waste water supply (108) with settling basin r~ (110), coarse and fine filter elements (120,126) filled with coal or activated coal and also ing devices (164) for garbage, a multi-reactor mile (104) with at least one thermolysis reactor (L86) and at least one pyrolysis reactor (178) which are arranged immediately close to each other, and pre-drying devices for garbage respectively. filter coal, characterized in that a pelletizing device (292) for pelletizing the coal from the thermolysis reactor (186) and grinding devices (295) are connected after the thermolysis reactor.