EP1203060B1 - Method and apparatus for utilizing gas from a sedimentation basin - Google Patents

Abstract

The invention relates to a method and a device for the disposal and utilization of all sorts of waste materials such as the disposal of industrial, domestic or special waste and related industrial products which have become waste products. The invention also relates especially to the elimination and utilization of gases which are absorbed by cooling water during the rapid cooling of a raw synthesis gas and are released into an area where they are allowed to settle. The waste material which is to be disposed of forms a gas-permeable aggregate (20) in a high-temperature area, wherein a raw synthesis gas is produced. The raw synthesis gas is rapidly cooled, in order to prevent new harmful substances from forming, by spraying cold water, whereupon it is cleansed and the cold water subsequently purified in the sedimentation basin (103). According to the invention, the gases which are released from the cold water in the sedimentation basin (103) are reintroduced into the material cycle or are transformed by heat.

Description

The present invention relates to a method and a device for disposal and utilization of waste of all kinds, in the unsorted, untreated, any pollutants in solid and / or liquid industrial, Household and special waste as well as industrial goods wrecks one Subjected to temperature exposure. In particular The invention relates to disposal and recovery of gases used in rapid cooling of raw synthesis gas from the cooling water be recorded and then in one Calming area of the cooling water from this again outgas. The present invention further relates to a device for the above method and to uses of the device according to the invention and procedures.

Form the known methods of waste disposal no satisfactory solution to the growing garbage problems, which is a major factor in environmental degradation are. Industrial wrecks made of composite materials, like motor vehicles and household appliances but also oils, Batteries, paints, paints, toxic sludges, medicines and hospital waste are subject to separate disposal measures strictly prescribed by law.

Household waste, on the other hand, is an uncontrolled heterogeneous Mixture that contains almost all types of hazardous waste fractions and contain organic components can and is not in terms of disposal yet Classified in relation to its environmental impact.

One of the disposal and recovery processes for Waste is waste incineration. With the known Waste incineration plants pass through the disposal goods a wide temperature range up to approx. 1000 ° C. At these temperatures, mineral and metallic residues are not melted, around subsequent gas production stages if possible disturb. The inherent in the remaining solids Energy is not used or is used only inadequately.

A short dwell time of the waste at higher temperatures and the high level of dust generation by default large amounts of nitrogen-rich combustion air in favor the uncompressed waste incineration goods the dangerous formation of chlorinated hydrocarbons. One has therefore gone over to the Exhaust gases from waste incineration plants afterburning undergo at higher temperatures. To the to justify high investments of such plants, the abrasive and corrosive hot exhaust gases their high dust content passed through heat exchangers. With the relatively long dwell time in the heat exchanger chlorinated hydrocarbons are formed again combine with the dusts carried along and ultimately to constipation and dysfunction lead and disposed of as highly toxic pollutants have to. Consequential damage and the cost of its elimination cannot be estimated.

Previous pyrolysis processes in conventional reactors have a width similar to that of waste incineration Temperature range. Rule in the gasification zone high temperatures. The hot gases that form are used to preheat the not yet pyrolyzed Used waste, cool down here and there also go through the chlorinated for the new formation Hydrocarbons relevant and therefore dangerous Temperature range. To be an ecologically safe to produce usable clean gas Pyrolysis gases as a rule before cleaning Crackers.

Together, the above described combustion and Pyrolysis the disadvantage that the during combustion or pyrolytic decomposition evaporated liquids or solids with the Mix and dissipate combustion or pyrolysis gases be before you destroy all Pollutants necessary temperature and dwell time in Have reached the reactor. The evaporated water is not made usable for water gas formation. Therefore usually become post-combustion chambers in waste incineration plants and crackers in pyrolysis plants downstream.

EP 91 11 8158.4 (EP-A-0 520 086) describes a method for disposal and utilization of waste goods known that avoids the disadvantages described above. there become the waste goods of a gradual application of temperature and thermal separation or conversion subjected and the accumulated solid residues converted into a high temperature melt. For this purpose, the goods to be disposed of are added in batches Compact packages compress and go through the temperature treatment stages towards increasing temperature from a low temperature level in which under Maintaining pressurization a form and frictional contact with the walls of the reaction vessel is ensured and organic components be degassed to a high temperature zone, in which the degassed waste is a gas permeable Bulk forms and controlled by Addition of oxygen synthesis gas is generated. This Syngas then becomes the high temperature zone derived and can be further used.

This derivation of the raw synthesis gas of the high temperature reactor is in turn fixed with a gas chamber connected to rapid gas cooling, which is a water injection device for cold water in the hot raw synthesis gas stream has. This rapid gas cooling (Shock cooling) prevents a renewed synthesis of Pollutants because the raw synthesis gas through the blast cooling the critical temperature range very quickly passes through and is cooled to a temperature, in which a new synthesis of the pollutants no longer takes place. This cold water injection into the raw synthesis gas stream also eliminates entrained in the gas stream Liquid or solid particles, so that after rapid cooling, a well pre-cleaned raw synthesis gas is obtained.

When cooling water is injected into the raw synthesis gas stream are essentially liquid or Solid particles taken up from the raw synthesis gas stream, which then in a calming zone (Sedimentation tanks), such as a lamella clarifier, be removed from the cooling water again, so that the cooling water in the circuit to cool the Raw synthesis gas stream and for the purification of this synthesis gas stream of liquid or solid particles can be performed.

A disadvantage of this method is that the cold water sprayed into the raw synthesis gas stream not only absorbs the liquid components and solid particles in the raw synthesis gas stream, but also dissolves or in the form of gaseous components of the synthesis gas, such as H ₂ S, CO, H ₂ and CO ₂ dispersed small gas bubbles. The cooling water is then fed into the sedimentation basin to separate the fine particles from the cooling water. However, the gaseous constituents mentioned in turn outgas from the cooling water, so that ultimately gaseous portions of the synthesis gas are carried off into the settling tank.

For environmental reasons, it is not possible to do this outgassing components directly into the environment derive.

US 4 141 695 discloses a method for gas purification, the quench water with an aqueous Emulsion and an organic extractant mixed and then separated again Remove impurities from the quench water. The quench water prepared in this way can then be used again be used.

The object of the present invention is to provide a method an apparatus and uses thereof for To provide with those in the sedimentation tank components that degas from the cooling water are environmentally friendly and disposed of or recycled at low cost can be.

This object is achieved by the method according to claim 1, the device according to claim 11 solved. Advantageous further training the inventive method and the inventive Device are in the dependent Given claims.

The inventive method follows that methods disclosed in EP-A-0 520 086. The procedure described there and the Device described there are invented now further developed by the fact that from the cooling water outgassing components in a calming area from this calming area ( Lamella clarifier) are suctioned off. That is it now possible to generate this gas, which its composition the purified raw synthesis gas corresponds, then in different ways and Way to recycle. In particular, the Degree of utilization of the entire plant and of the whole Process improved and the environment from the out of the Components that outgass cooling water are spared.

According to the invention, the gas from the sedimentation basin passed back into the raw synthesis gas stream be, on the one hand, before the rapid cooling can take place or also in the raw synthesis gas stream, that leaves the rapid cooling. Because that from Gas that outgasses cooling water already has rapid cooling go through and is sufficiently cooled and cleaned to with the exiting from the rapid cooling Raw synthesis gas stream to be mixed.

Alternatively, that which emerges from the cooling water Gas mixed with fuel gas even with the exclusion of oxygen and then in a combustion chamber be thermally recycled.

However, the extraction must be explosion-proof. This also applies to an extraction system Subsequent optional compression of the cooling water escaping gas.

This is particularly advantageous from the cooling water leaked gas then again in the High temperature area of the reactor fed back. To do this, however, the pressure difference between the leaked relaxed gas and the high temperature reactor be overcome. Therefore in this case compression of the gas is absolutely necessary. It is particularly advantageous if the gas is out the settling tank before it is fed into the high temperature area fuel gases still under exclusion of oxygen, for example natural gas or synthesis gas be and then this gas mixture over Lances are introduced into the high temperature reactor.

This last possibility has the decisive one Advantage that the leaked gases are completely energetic and be recycled and the reaction gases the complete cycle of the invention Go through procedure. With this, since the Exhaust gases from this combustion process both in the High temperature zone are treated as well afterwards the rapid cooling and the further cleaning stages go through the process, any pollutant emissions into the environment avoided.

The following are some examples of an inventive one Method and an inventive Device will be described.

Fig. 1

eine erfindungsgemäße Vorrichtung;

Fig. 2

eine erfindungsgemäße Vorrichtung; und

Fig. 3

eine weitere erfindungsgemäße Vorrichtung.

Show it:

Fig. 1

a device according to the invention;

Fig. 2

a device according to the invention; and

Fig. 3

another device according to the invention.

1, the method steps 1) to 5) are symbolized. The waste is processed without pretreatment, i.e. without sorting and without shredding, level 1) supplied in which it is compacted. Here will the compaction result improved significantly if pressing surfaces in the vertical and horizontal direction Act. A high compression is necessary because the feed opening of the push channel in which the Process stage 2) takes place through the highly compressed Waste plug is sealed gas-tight.

The highly compressed waste goes through in stage 2) a thrust channel 6 with exclusion of oxygen at temperatures up to 600 ° C. Organic components of the Waste are degassed. The gases flow through the Shear furnace 6 waste in the direction of the process stage 3). They contribute to this flow as well as a good heat transfer as the intensive Pressure contact of the waste with the push furnace walls. As a result of the constant feeding of the highly compressed This pressure contact remains the entire length of the furnace and the entirety of the channel surfaces received so that at the end of the waste cycle degassing of the organic through the thrust channel Substances is largely complete.

Smoldering gases and water vapor as it comes from natural Waste moisture originates from metals, minerals and the carbon of the degassed organics become common the process stage 3) supplied in the first the carbon is burned with oxygen. The here at temperatures of up to 2000 ° C and more melt the metallic and mineral Components so that they are in the process step 5) can be discharged molten.

At the same time, the organic compounds of the carbonization gases are destroyed over the high-temperature range of the glowing carbon bed at temperatures of more than 1000 ° C. As a result of the reaction equilibria of C, CO ₂ , CO and H ₂ O at these temperatures, synthesis gas is formed, consisting essentially of CO, H ₂ and CO ₂ , which is suddenly cooled to below 100 ° C. in process step 4). The rapid cooling prevents the formation of new organic pollutants and facilitates the subsequent gas scrubbing. Thereafter, high purity synthesis gas is available for any use.

In the process known to this extent, the high-purity synthesis gas can have a volume flow dependent on the waste composition and quantity and also a varying concentration of hydrogen. Therefore, after the gas scrubbing, the volume flow and the hydrogen content of the purified synthesis gas are determined and these values are fed to a control system. This control now controls, as described above, the supply of oxygen and the supply of fuel, for example natural gas or synthesis gas in process stage 3), in which the previously degassed waste gasifies at temperatures of up to 2000 ° C. by adding 0 ₂ becomes. By changing the fuel input or the oxygen supply, both the volume flow and the hydrogen content of the synthesis gas produced can be influenced. By means of this regulation, a gas synthesis gas with a regulated constant volume flow and also a regulated constant hydrogen content is therefore available to the gas utilization after the gas scrubbing.

Those discharged in the molten state in process step 5) Metals and minerals are useful post-treatment with oxygen subjected to more than 1400 ° C. This entrains Removes carbon and mineralization completed. The discharge of the solids, for example in a water bath, closes the disposal process from. In the after the discharge of the solids granules obtained in a water bath themselves metals and alloying elements and complete mineralized non-metals side by side. ferroalloys can be separated magnetically. The Leach-proof mineralized non-metals can can be reused in many ways, for example in expanded pellet form or - processed into rock wool - As an insulating material or directly as granules for Fillers in road construction and in the production of concrete.

Fig. 1 also shows typical in the individual areas Process data of an exemplary advantageous Process implementation. Degassing is a function the temperature T, the time, the pressure and the Waste composition.

The composition and the volume flow now depend of the available carbon, oxygen and water vapor from. By regulating the amount of Available carbon (fuel supply for Gas phase) and oxygen (oxygen supply via oxygen lances is controlled in the gas phase) the composition of the synthesis gas that already a relatively high quality in the known method owns, further optimized and is therefore suitable ideal for use e.g. in gas engines for electricity generation or for chemical processes.

In Fig. 1 the compression is carried out by a compression press 1, the structure of a well-known Corresponds to scrap press, e.g. For the scrapping of vehicles is used. A swiveling press plate 2 enables loading the press 1 with mixed waste. A pressing surface 3 is located itself in the left position so that the loading space the press is fully open. By the Swinging the press plate 2 into the horizontal shown Position, the waste is initially vertical Direction condensed. Then the moves Press surface 3 horizontally in the solid lines shown location and compacted the waste package in the horizontal direction. The necessary for this Opposing forces are not shown by a extendable and retractable counter plate included. After the compaction process is complete, the counter plate is extended and the compacted Waste plugs with the help of those moving to the right Press surface 3 in an unheated area 5 of the push oven 6 and thus its total content transported accordingly, recompressed and in pressure contact with the duct or furnace wall held. Then the pressing surface 3 in the left end position moved back, the counter plate retracted and the pressure plate 2 in the dashed shown vertical position pivoted back. The Compression press 1 is ready for a new loading. The waste compaction is so great that the in inserted the unheated area 5 of the push oven 6 Waste plug is gastight. Heating the Pusher furnace is made by flame and / or exhaust gases flow through a heating jacket 8 in the direction of the arrow.

When the compressed waste is pushed through the furnace channel 6, a degassed zone spreads out towards the central plane of the pusher furnace 6, favored by the large surface area associated with the side / height ratio> 2 of its rectangular cross section. When entering a high-temperature reactor 10, there is a mixture of carbon, minerals, metals and partially decomposed gasifiable components which is compacted by the constant pressurization during the passage. This mixture is exposed to extremely high radiant heat in the area of the inlet opening into the high-temperature reactor. The associated sudden expansion of residual gases in the carbonized material leads to its fragmentation. The solid piece goods obtained in this way form a gas-permeable bed 20 in the high-temperature reactor, in which the carbon of the carbonized material is first burned to CO ₂ or CO using oxygen lances 12. The smoldering gases flowing through the reactor 10 swirling above the bed 20 are completely detoxified by cracking. Between C, CO ₂ , CO and the water vapor expelled from the waste there is a temperature-related reaction equilibrium in the synthesis gas formation. This raw synthesis gas is passed via a raw synthesis gas line 100 to a container or chamber 14, in which the synthesis gas is shock-cooled to less than 100 ° C. by water injection. Components entrained in the gas (minerals and / or metal in the molten state) are separated in the cooling water, water vapor is condensed, so that the gas volume is reduced and gas cleaning is thus facilitated, which can follow the shock cooling in known arrangements. The water used for the shock-like cooling of the synthesis gas stream can, if appropriate, be used again for cooling after purification and consequently be circulated. In the rapid cooling of the raw synthesis gas by spraying cooling water into the raw synthesis gas stream, not only are liquid components and solid components (dusts, etc.) removed from the raw synthesis gas, but the cooling water also absorbs gas components from the raw synthesis gas. This is done, for example, by emulsifying the finest gas bubbles in the cooling water or by dissolving gases from the raw synthesis gas. The mineral and metallic constituents of the carbonized material are melted in the core area of the bed 20, which is hotter than 2000 ° C. Due to the different density, they overlap and separate. Typical alloying elements of iron, such as chromium, nickel and copper, form a smeltable alloy with the iron of waste, other metal compounds, for example aluminum, oxidize and stabilize the mineral melt as oxides.

The melts enter directly into an aftertreatment reactor 16, in which they are exposed to temperatures of more than 1400 ° C. in an oxygen atmosphere introduced with the aid of an O ₂ lance 13, optionally supported by gas burners (not shown). Carried carbon particles are oxidized, the melt is homogenized and its viscosity is reduced.

When they are discharged together into a water bath 17 granulate mineral and molten iron separately and can then be sorted magnetically.

The cooling water is from the container 14 via a Outlet 102 in a calming area, here one Lamellar clarifier 103 directed where the contained in it Solids, e.g. Suspended components, settle and removed through a slurry outlet 104. The cooling water purified in this way is passed through a Water outlet 105 and a water inlet 107 in the Container 14 again for cooling the raw synthesis gas used and consequently in a cycle. The cleaned raw synthesis gas leaves the container 14 via a discharge line 101 to subsequently a delicates wash or to be subjected to fine cleaning.

In the lamella clarifier 103 forms above the standing one Sewage water a gas space 106, in which the dissolved and emulsified gas components of the cooling water outgas. This gas space is through a gas outlet 110 with a suction and compression device 111 connected. This suction and compression 111 sucks the gas components escaping from the cooling water from the airspace 106 and compresses them to them to bring a pressure that is above the pressure in the High temperature reactor 10 is. Following the The gas is compressed with a fuel, for example Natural gas or synthesis gas via a fuel feed line 112 and then over a Gas nozzle 113 introduced into the high-temperature reactor, where it burned completely and the one in the High temperature reactor processes becomes.

The advantage of this return line of the gas is that whose combustion gases now also reach the cracking stages in the high temperature reactor and the subsequent one Subjected raw synthesis gas scrubbing in the container 14 again become. All in all, it becomes complete emission-free disposal and thermal recycling of the gas outgassing from the cooling water.

2 shows a further device according to the invention, the same with the same reference numerals Components and parts are designated. The difference to the device in Fig. 1 now the gas emerging from the cooling water in the gas space 106 collected and via a gas outlet 120 of a suction and compression device 121 supplied. The components outgassing from the cooling water correspond the raw synthesis gas, so that it is as in FIG. 2 shown in the container 14 prior to rapid cooling in the tube synthesis gas stream 100 via a gas supply 122 can be initiated. In this case too Completely emission-free disposal or recycling of these outgassing components.

Since the outgassing components already Have cooled down rapidly, the feed can of these outgassing components in the raw synthesis gas stream even after rapid cooling in the Container 14 in the discharge line 101 of the purified raw synthesis gas for delicate washing.

3 shows a further device according to the invention, where also the same reference numerals as in Fig. 1 for the same components and elements be used.

In contrast to Fig. 1, the components outgassing into the gas space 106 via lines 130 and 134 fed to a combustion chamber 131, where they burned 133 with low emissions under oxygen and the combustion gases over a fireplace 132 released into the environment.

Claims (15)

1. A method of disposing of and utilizing waste substances of all types, in which unsorted and untreated industrial or domestic refuse and/or refuse requiring special treatment as well as discards of industrial products, which contain any pollutants in solid and/or liquid form, are subjected to the action of temperature and thermal separation or conversion of materials in a step-wise manner, and the solid residues formed are passed on into a high-temperature melt, wherein the material for disposal, compressed batch-wise to form compact packets, passes through the temperature-treatment stages in the direction of rising temperature with at least one low-temperature stage, in which positive and non-positive contact with the walls of the reaction vessel (6) is carried out with the exclusion of oxygen and while maintaining the action of pressure, and with at least one high-temperature zone, in which the material for disposal forms a gas-permeable fill (20) and crude synthesis gas is produced while oxygen is supplied, wherein the crude synthesis gas produced is diverted from the high-temperature zone and is shock-cooled by being sprayed with cooling water and the cooling water is conveyed into a sedimentation basin (103), characterized in that the gases issuing from the cooling water in the sedimentation basin are drawn off, compressed and fed to the crude synthesis gas before or after the rapid cooling of the crude synthesis gas or are thermally converted in a combustion chamber (19, 131).
2. A method according to Claim 1, characterized in that combustion gas is admixed with the gases issuing and drawn out from the cooling water in the sedimentation basin (103).
3. A method according to the preceding Claim, characterized in that the combustion gas is admixed while oxygen is excluded.
4. A method according to one of the preceding Claims, characterized in that the gases issuing from the cooling water in the sedimentation basin (103) are conveyed into the high-temperature zone of the combustion chamber (10) and there they are vigorously converted with respect to their materials.
5. A method according to one of the preceding Claims, characterized in that the drawing off and compression of the gases issuing from the cooling water in the sedimentation basin (103) are carried out in an explosion-proof manner.
6. A method according to one of the preceding Claims, characterized in that the low-temperature step is carried out in the temperature range of between 100°C and 600°C.
7. A method according to the preceding Claim, characterized in that the carbon portions in the fill (20) are gasified to form carbon dioxide and carbon monoxide by the metered addition of oxygen, wherein the carbon dioxide is reduced to carbon monoxide during the penetration of the carbon-containing fill (20), and hydrogen and carbon monoxide are produced from the carbon and highly heated water vapour.
8. A method according to one of the preceding Claims, characterized in that the high-temperature step is carried out at temperatures of more than 1000°C.
9. A method according to one of the preceding Claims, characterized in that immediately after leaving the high-temperature reactor (10) the diverted synthesis gas is subjected to the shock-like action of water until cooling to below 100°C and, during this, it is freed from dust.
10. A method according to one of the preceding Claims, characterized in that the content of hydrogen and/or the volume flow of the diverted synthesis gas is or are determined after the shock-like cooling, and the content of hydrogen and/or the volume flow of the diverted synthesis gas is or are regulated accordingly.
11. A device for the preparation, conversion and after-treatment of material for disposal of all types with a plurality of thermal treatment stages which include at least one low-temperature stage (6) with the exclusion of oxygen and at least one high-temperature stage (10) with the supply of oxygen at temperatures of over 1000°C, and with an outlet for the crude synthesis-gas mixture produced in the high-temperature stage, wherein all the reaction spaces of the treatment stages are connected to one another in a fixed and lock-free manner, and devices for feeding in oxygen and devices for feeding in fuel are provided in the high-temperature stage (10), and with a chamber (14) for rapidly cooling the crude synthesis-gas mixture with cooling water, for example by spraying the cooling water into the flow of crude synthesis gas, and a sedimentation basin (103) for the cooling water, characterized in that the sedimentation basin (103) is connected to a suction device (111, 121) for the gases issuing from the cooling water and to a device for the compression (111, 121) of the gases issuing from the cooling water, and the suction device (111, 121) has an outlet for the gas which is drawn off and has issued from the cooling water, the outlet being connected to the high-temperature stage (10), the crude synthesis-gas path upstream (100) and/or downstream (101) of the chamber (14) for rapid cooling and/or to a combustion chamber (131).
12. A device according to Claim 11, characterized in that it comprises a device for adding combustion gas by mixing to the gas which is drawn off and has issued from the cooling water.
13. A device according to Claim 11 or 12, characterized in that the chamber (14) for rapid cooling comprises a device for injecting cold water into the hot flow of the synthesis-gas mixture.
14. A device according to one of Claims 11 to 13, characterized in that the outlet for the synthesis-gas mixture comprises a throttle device, for example a throttle flap capable of being regulated.
15. A device according to one of Claims 11 to 14, characterized in that a device for cleaning the gas is arranged upstream or downstream of the outlet for the synthesis-gas mixture.

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