Process and plant for the reduction of low molecular weight, water-soluble organic compounds in fine, mineral sieve fractions

Abstract

A method for reducing low molecular weight, water-soluble organic compounds in fine, mineral sieve fractions, comprising the steps of: - (i) heaping the sieve fraction into a pile (1), either into a pile with a sufficiently dense packing or additionally by arranging it under a cover so that an anaerobic atmosphere develops inside the pile, - (ii) moistening the sieve fraction to a defined dry matter content, - (iii) measuring a temperature in a part of the pile (1) at at least one measuring point (4), - (iv) storing the pile (1) with a dense packing or under a cover for at least a defined period of time, the storage being carried out while maintaining the anaerobic atmosphere;- (v) Terminating the microbiological anaerobic degradation within a specific time and / or temperature window after reaching a maximum temperature T1 in the stockpile (1) and dropping to a temperature T2 at which a large part of the microbial degradation has taken place, and - (vi) Drying the stockpile (1) after the storage has ended by redistributing or turning over at least part of the stockpile, so that the low molecular weight organic compounds formed in the stockpile evaporate at least partially.;

Description

[0001] The invention relates to a process for the reduction of low molecular weight, water-soluble organic compounds Compounds in fine, mineral sieve fractions.

[0002] The invention further relates to a landfill plant for reducing low molecular weight, water-soluble organic compounds in fine, mineral sieve fractions.

[0003] In the mechanical waste treatment of construction site and commercial waste, fine mineral Sieve fractions, hereinafter referred to as the fine fraction, have been sieved. This mineral fine fraction often contains water-soluble substances. Organic compounds in concentrations that prevent legally compliant landfill disposal. The DOC limit (Dissolved Organic Carbon) according to the Landfill Ordinance (DepV) for a Class III landfill is 24 for an aqueous 3 Hours eluate at a water-to-dry matter ratio of 10:1 at 100 mg-C / dm³ and can be by 3 An exemption application can be made to increase the maximum limit to 200 mg-C / dm³. In many cases, the DOC limits for the fine fraction are increased. This limit is exceeded, preventing their cost-effective disposal.

[0004] Against this background, the invention was based on the objective of eliminating the disadvantages known in the prior art. to overcome as much as possible. In particular, the invention was based on the objective of providing a method and a Landfill facility for the reduction of low molecular weight, water-soluble organic compounds in fine, mineral particles to specify sieve fractions that reduce the DOC values ​​of the fine fraction.

[0005] The invention solves the problem in a first aspect with a method for reducing low molecular weight, water-soluble organic compounds in fine, mineral sieve fractions of the type mentioned above, comprising the steps: (i) heaping the screened fraction into a pile, in particular into a pile of dense fill, in the (ii) Moistening the sieve fraction to a defined dry matter content, (iii) measuring a temperature in a part of the stockpile at at least one (iv) measuring location, (iv) storing the pile for at least a defined period of time, (v) drying the pile.

[0006] In a first step of the process according to the invention, the fine fraction is piled up to form a heap. To initiate anaerobic microbiological degradation, the pile is moistened as needed. It should be understood that... that the moistening step is omitted if the piled material already has a defined moisture content The dry matter content (DM content) is measured by drying at 105 °C until... Constancy of weight (DIN EN 14346: 2007-03). Moisture is sufficiently good if the fine particles are in a dense... The bulk material heats up quickly.

[0007] Large quantities are preferentially broken down by microbiological anaerobic degradation over a period of up to several weeks. Water-soluble organic compounds are broken down into short-chain, water-soluble organic compounds. Microbiological degradation nears its end when the temperature in the pile, preferably in the middle of the The DOC value of the fine fraction decreases in the heap or in a medium range. This decrease is only due to microbial degradation. Significantly altered. The purpose of anaerobic microbiological degradation is to break down large, water-soluble organic compounds. to convert them into small, short-chain compounds with significant vapor pressure. A typical example would be the Breakdown of water-soluble polysaccharides to carboxylic acids such as acetic acid.

[0008] In a further step of the process, the anaerobically, microbiologically treated fine fraction is aerated or dried. In addition to water, the newly formed, short-chain organic compounds also evaporate. With As the degree of dryness increases, the DOC value of the fine fraction also decreases. Since the typical evaporable, water-soluble Low drying levels also indicate an organic content in the range of approximately 2 g / kg of original substance (OS). Significant reductions in the DOC of the fine fraction. The evaporation or drying of the fine fraction can also be caused by Multiple sievings should be carried out at ambient temperature. It is essential that as much water and short-chain proteins as possible are used. Organic compounds evaporate. The exhaust air from the drying process can optionally be filtered through a biofilter. gaseous organic compounds are freed.This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality.

[0009] In a preferred embodiment, steps i, ii, iv and v follow one another and step iii is performed single, multiple or continuous between one, several or all of steps i, ii, iv and v. For success A specific temperature profile is important for the process. Initially, the temperature rises to a certain value. After a certain time, the temperature drops again. To achieve a good result, it is helpful to monitor the process. to interrupt the microbiological anaerobic degradation within a certain time or temperature window. In order to To optimize and monitor the process, recording a temperature curve can be useful. be. But also individual Mes Singing within the process may be sufficient to ensure the success of the process, in particular the reduction of the DOC- to achieve the value of the sieve fraction.

[0010] Furthermore, it is preferred that the piling and / or storage of the stockpile involves arranging the stockpile under a cover, especially a tarpaulin. This makes it easy to ensure that the pile... is largely or substantially shielded from atmospheric oxygen, so that an anaerobic An improved atmosphere can develop within the pile. A tarp is a simple way to create this. such a cover.

[0011] Preferably, the temperature is measured at the at least one measuring point inside the pile, preferably in a non-surface or alternatively middle area, particularly preferably at a depth greater than 100 cm, particularly preferably in a depth range of 100 cm to 200 cm, starting from the outer contour of the pile. This ensures that the measured temperature is subject to the lowest possible deviation caused by disturbances. It is subject to fluctuations. A representative value that is characteristic of the start and course of the microbial The depth of degradation is preferably measured from a certain depth, starting from the outer contour of the stockpile. To avoid measurement errors due to temperature fluctuations within the pile, the temperature is preferably set at To measure at a defined measurement location and within a defined depth range. The measurement location can be chosen arbitrarily. A middle area is defined as an area within the pile which has at least one [dimension] in all directions. has a distance of 100 cm to the ground, a wall or the surface of the pile.

[0012] Furthermore, it is preferred that the piled-up material at the measuring point has a temperature T at a start time t. 0 0 exhibits and the moistened sieve fraction has a temperature T after an initial storage period t, 1 1 where T > T, and where T corresponds to a maximum temperature of the stockpile within the process. During the 1 0 1 During microbiological degradation, the temperature within the pile rises to a maximum value. Thus, it increases from an initial value T over time to a maximum value T. After reaching the maximum value... 0 1 The temperature of the pile decreases, which is determined particularly at the measuring point. Here, the Microbiological degradation within the sieve fraction comes to an end.

[0013] Furthermore, it is preferred that the first temperature T is in a temperature range of 50 °C to 80 °C, preferably 1 within a temperature range of 60 °C to 75 °C. The maximum temperature depends on various factors. These include the ambient temperature, the size of the pile, the density of the pile, and the geometry. of the heap.

[0014] Preferably, the piled-up material exhibits the following characteristics at the measuring point after a second period of time t during storage. 2 a temperature T, where T < T and, in particular, T > T. As mentioned in the section above, the 2 2 1 2 0 Temperature after reaching temperature T. This is an indicator that a large part of the microbial degradation has occurred. 1 has already occurred. The temperature T is characteristic of the end of storing the stockpile for the purpose of 2This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality. microbial degradation and thus triggers the start of the drying process step of the pile. In the event of a demolition To ensure the most effective possible evaporation of the liquid phases during microbial degradation at a temperature T, 2 within the pile.

[0015] Preferably, the second time period t lies in a time range of 3 d to 20 d starting from to, preferably in 2 a time range of 5 to 10 days. A key characteristic for the most optimal possible end of microbial degradation is, above all, the temperature T. In the event that the framework conditions, such as pile size, ambient temperature, etc., 2 The time range is also characteristic of an optimal end to the storage period and consequently of the [missing information]. microbial degradation.

[0016] In a further preferred embodiment, the second temperature T is in a temperature range of T2, 2 min=T0+(T1-T0)*0.2 to T2,max=T0+(T1-T0)*0.6; preferably in a temperature range from T = 20 °C to T = 60 2,min 2,max °C, particularly preferably within a temperature range of T = 30 °C to T = 50 °C. An optimal end is desired. 2,min 2,max The range of microbial degradation can be extended to a preferred temperature range. Within this range... Within the temperature range, the microorganisms have largely converted the organic compounds into short-term carboxylic acids. The aim of the process is to convert as large a proportion of the organic compounds as possible into ethanol. is converted. If the process lasts longer, acetic acid is formed, which is more difficult to convert than ethanol. evaporation. A similar problem can arise with a shorter process duration. Nevertheless, the The DOC value, and thus the objective of the process, can also be achieved by evaporating another liquid carboxylic acid.

[0017] Furthermore, it is preferred that the sieved fraction has a dry matter content of preferably 55% to 90%, especially preferably moistened to a dry matter content of 70% to 85%. It has been shown that in this range The anaerobic bacteria are particularly good at converting the multi-component organic matter of the sieve fraction, given the high dry matter content.

[0018] Preferably, the drying of the pile comprises one, several or all of the following steps: - Arranging at least part of the pile in a drying device, - drying the pile by means of the Drying device for a third defined time period t , - Drying of the pile using the drying device T for one or more further defined time periods t , - extraction of exhaust air using an exhaust air device into a Tx Biofilter, - Storing the pile for a period of time t. The drying process can vary considerably. L In a preferred embodiment, drying is primarily carried out by means of circulation at least a portion of the stockpile. This process can remove short-chain carboxylic acids and water from the stockpile, or... the sieve fraction, evaporate.

[0019] Furthermore, drying is preferably carried out using a drum screen, a conveyor belt, a fine trough, a The drying process itself is carried out using a shovel and / or a wheel loader. No special equipment is required for the drying process itself. Drying device.

[0020] It is helpful if the pile is distributed in such a way that the surface area of ​​the pile is as large as possible. This can increase the efficiency of the evaporation process. This can be achieved, for example, by spreading out the sieve fraction. of the pile on a conveyor belt, by vibrating the screened fraction in a fine trough, by redistributing the heap by means of a wheel loader or bucket, or by turning over the screened fraction within a Drum screen.This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality.

[0021] In a further preferred embodiment, the heap exhibits, after being filled and / or during the 3 3 Storage areas range in size from 300 m² to 1000 m², depending on storage capacity and the material to be processed. Depending on the sieve fraction volume per day, a corresponding stockpile size must be selected. The storage time or drying time can be determined in The size of the pile will vary depending on the situation.

[0022] Furthermore, it is preferred that the piling and / or storage of the stockpile involves arranging the stockpile under a roof. The roof provides simple protection for the pile from environmental influences such as... Protected from rain. This ensures that the dry matter content of the product remains high even during storage. The stockpile is not significantly altered.

[0023] In a second aspect, the problem underlying the invention is achieved by a landfill facility for Reduction of low molecular weight, water-soluble organic compounds in fine, mineral sieve fractions, in particular to carry out a procedure which, according to at least one of the above-described preferred embodiments comprise: a base for placing a heap of at least one Sieve fraction on the floor, a temperature measuring device for measuring a temperature at a measuring point within of the heap, a drying device, in particular a drum sieve, for drying the heap.

[0024] It should be understood that the landfill facility according to the second aspect has similar and identical preferred It offers further training and advantages, so reference is made to the above.

[0025] According to a preferred embodiment, the landfill facility further comprises an exhaust air system for extracting the Air during the drying of the pile and / or a biofilter to clean the extracted air. The exhaust system serves to extract the gases produced mainly by evaporation during storage. of the heap or the drying of the sieved fraction, especially within a hall.

[0026] Preferably, the landfill facility further comprises a roof for arranging the stockpile below the Canopy.

[0027] It is further preferred that the landfill facility also includes at least one conveyor belt and / or a vehicle for loading. and includes the transport of bulk goods, in particular a sieved fraction.

[0028] The invention is described below with reference to exemplary embodiments and the accompanying figures. described in more detail. Here we show: Fig. 1: a first embodiment of a landfill facility according to the invention; Fig. 2: at least one partial embodiment of the process sequence according to the invention; as well as Fig. 3: a schematic temperature profile of a pile of material, measured at a measuring point during the Process step of storage.

[0029] Fig. 1 shows a landfill facility 100 with a hall 14, which has a roof 16 and a floor 18. Inside In Hall 14, particularly below the roof 16 and on the floor 18, there is a heap 1 of a sieve fraction arranged.This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality.

[0030] For transporting the pile 1 for repositioning or turning over, a wheel loader can be used, as shown in Fig. 1. 20 are used. Furthermore, a drum sieve 6 is shown within hall 14. This serves to... The stockpile 1 is dried after storage by means of agitation. Hall 14 also has an exhaust air system 10, which equipped with a biofilter 12.

[0031] In this embodiment, a temperature measurement, in particular inside the pile 1, is carried out. by means of a temperature measuring device 2, in particular a probe. This allows a measuring point to be determined in a simple manner. 4 in a consistently recurring depth position starting from the outer contour of the pile 1 between Various measurements are guaranteed.

[0032] To carry out the process according to the invention, the sieved fraction is to be piled up into a heap 1. To initiate anaerobic microbiological degradation within pile 1, pile 1 must be moved to a defined level. to moisten the dry matter content. This step can be done before or after adding the sieve fraction to a Heap 1 is carried out and is omitted if the sieved fraction already has the defined dry matter content, see See also Fig. 2. One or more measurements of the dry matter content of the sieve may be necessary. to carry out.

[0033] Furthermore, the temperature can then be measured at a measuring point 4 in a part of the pile 1. This step is optional and can also be performed once, multiple times, or during the storage period of stockpile 1. The measurement is carried out continuously. The temperature is preferably measured at a measuring point 4 within the pile 1. measured.

[0034] Following this, the storage period of the stockpile 1 begins for at least a defined period of time. Fig. 3 shows For example, a temperature curve measured at a measuring point 4 within a stockpile 1 during storage. was. The storage time in days is plotted against the temperature in °C. As soon as the conditions for starting the The requirements for anaerobic storage are met, including, among other things, a sufficiently dense layer of the sieved fraction and a Once the defined dry matter content is reached, the anaerobic storage process begins; see process step 2 of Fig. 2. In this process, organic components of the sieve fraction are converted into short-chain carboxylic acids by means of microorganisms. During the transformation, the temperature within pile 1 increases. This is also a characteristic of a The most successful possible process start, in particular an increase in temperature starting from T. During the 0 During anaerobic storage, the temperature rises to a maximum value T. This is preferably in the range of 1 65–90 °C. This value can fluctuate, due in part to external influences. Geometry of pile 1 during storage and composition of pile 1.

[0035] According to the invention, it is also provided that the pile 1 is placed under a tarpaulin or at least a roof. to arrange. This has the advantage that the set dry matter content of stockpile 1 during storage This can be adhered to. Furthermore, improved shielding against [unclear] can be achieved, particularly by means of a tarpaulin. Environmental influences, especially oxygen, must be ensured.

[0036] After a certain period of time, in particular after a period of time t, the temperature drops from 1 T. This indicates that a large proportion of the microbial transformation has occurred within the sieve fraction. The 1 Storage should ideally be terminated at a temperature T. A favorable termination window can be found at a 2 The temperature range was extended from T to T. The organic content of pile 1 was then increased to 2,min 2,max a large portion is converted into easily vaporizable ethanol.

[0037] A controller can optionally be used to monitor the abort time window. The controller This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality. The stockpile 1 falls within the temperature range of the demolition time window, i.e., in particular within a temperature range of T 2, up to T. The output signal can be, for example, a light signal or a sound signal for transmission to min 2,max a worker who can initiate the subsequent process steps. In addition, the control system can monitor temperature profiles. record.

[0038] In a next step, the drying of the pile 1 can therefore be carried out in a particularly simple manner. This This can be done, for example, by circulating the sieve fraction in a drum sieve 6. For this purpose, the sieve fraction of the The pile 1 is conveyed into the drum screen 6 by means of a wheel loader 20. The drying process begins there. during the reloading of the sieve fraction from the pile 1 to the drum sieve 6. The dry The drying process is carried out for a drying time t. This can be adjusted according to requirements, i.e., the desired DOC value. T The sieve fraction can be varied and lengthened or shortened as needed. It is also conceivable to add another sieve fraction. To perform a drying process after an initial drying process, for example if the desired target value has not yet been achieved.

[0039] Following the drying process, the sieved fraction can optionally be piled up to form a new heap 8 If necessary, a new storage period t can be started so that any remaining residual moisture within the L The sieved fraction can evaporate during the storage time t. The storage time can be varied as needed and also adjusted by L One or more additional storage times t can be added. With increasing storage time t, the DOC value of the Lx L The sieve fraction will be reduced.

[0040] The gases produced during evaporation can be extracted by means of an exhaust air device 10, which is located in this In an exemplary embodiment equipped with a biofilter 12, the air can be extracted. 3

[0041] A suitable stockpile volume 1.8 has proven to be a size of 300-1000 m³. This can also be adjusted depending on The storage capacity of the landfill facility 100 can be further expanded or reduced.

[0042] A practical embodiment is described below: A commercial waste / construction waste / fine-grained fraction with a TOC (Total Organic Carbon) value of approximately 10% and 3 With a DOC value of 200 mg / dm³, it is moistened to a dry matter content of approximately 80% and then left for 10 days. The material is stored in a pile under anaerobic conditions, where it self-heats to approximately 65 °C. The fine grain is then... then twice in a fine-mesh drum sieve, with a residence time of approximately 2 minutes each time. 3 dried. A reduction in the DOC value to below approximately 100 mg / dm³ is observed. Reference symbol list 1 heap 2 Temperature measuring device 4. Measurement location 6 drum sieve 8 Heaps after drying 10 Exhaust air system 12 BiofilterThis text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality. Hall 14 16 Roofing 18 Floor 20 wheel loaders 100 landfill site

Claims

1. Method for the reduction of low molecular weight, water-soluble organic compounds in fine, mineral particles Sieve fractions, encompassing the steps: - (i) Heaping the screened fraction into a heap (1), in particular into a heap of dense bulk material, in such a manner, that an anaerobic atmosphere builds up inside the pile, - (ii) Moistening the sieved fraction to a defined dry matter content, - (iii) Measuring a temperature in a part of the stockpile (1) at at least one measuring point (4), - (iv) Storing the stockpile (1) for at least a defined period of time, - (v) Drying the pile (1).

2. The method of claim 1, wherein steps i, ii, iv and v are performed consecutively and wherein step iii is performed only once, multiple or continuous exchanges occur between one, several or all of steps i, ii, iv and v.

3. Method according to claim 1 or 2, wherein the piling and / or storage of the stockpile (1, 8) is an arrangement of the Pile (1.8) under a cover, in particular a tarpaulin.

4. Method according to at least one of the preceding claims, wherein the temperature at the at least one measuring point (4) is measured inside the stockpile (1), preferably not near the surface or in a middle area, especially preferably at a depth greater than 100 cm, especially preferably in a depth range of 100 cm to 200 cm, starting from the outer contour of the pile (1).

5. Method according to at least one of the preceding claims, wherein the piled heap (1) at the measuring point (4) at a start time t has a temperature T and the moistened sieve fraction after a first time period t 0 0 1 during storage, it has a temperature T, where T > T, and where T is a maximum temperature of the stockpile. 1 1 0 1 (1) within the procedure.

6. The method of claim 5, wherein the first temperature T is in a temperature range of 50 °C to 80 °C, 1 preferably in a temperature range of 60 °C to 75 °C.

7. Method according to one of claims 5 or 6, wherein the heaped pile (1) at the measuring point (4) according to a second time period t during storage has a temperature T, where T < T and in particular T > T. 2 2 2 1 2 0 8. Method according to claim 7, wherein the second time period t lies in a time range of 3 d to 20 d starting from t, 20 preferably in a time range from 5 d to 10 d.This text has been copied by the DPMA from the original sources. It does not contain any drawings. The tables and formulas may be of unsatisfactory quality.

9. Method according to one of claims 7 or 8, wherein the second temperature T is in a temperature range of T2, 2 min=T0+(T1-T0)*0.2 to T2,max=T0+(T1-T0)*0.6,preferably in a temperature range from T = 20 °C to T = 60 2,min 2,max °C is particularly preferably in a temperature range of T = 30 °C to T = 50 °C. 2,min 2,max 10. Method according to at least one of the preceding claims, wherein the sieved fraction is reduced to a dry matter content is moistened to a dry matter content of preferably 55% to 90%, particularly preferably to 70% to 85%.

11. Method according to at least one of the preceding claims, wherein the drying of the pile (1) involves one or more or includes all of the following steps: - Arranging at least part of the pile (1) in a drying device (4), - Drying the pile (1) using the drying device (4) for a third defined time period t , T - Drying the pile (1) using the drying device (4) for one or more further defined time periods t , Tx - Extraction of exhaust air into a biofilter using an exhaust air device (12), - Storing the pile (8) for a period of time t . L 12. Method according to claim 11, wherein the drying is primarily carried out by means of a rotating of at least a part of the pile. (1) is executed.

13. Method according to claim 11 or 12, wherein the drying is carried out using a drum screen (6), a conveyor belt, a fine channel, a shovel, and / or a wheel loader (20).

14. Method according to at least one of the preceding claims, wherein the heap (1,8) after the heaping and / 3 3 or has a size of 300 m to 1000 m during storage.

15. Method according to at least one of the preceding claims, wherein the piling and / or storage of the stockpile (1,8) includes arranging the pile (1,8) under a tarpaulin and / or a roof (16).

16. Landfill facility (100) for reducing low molecular weight, water-soluble organic compounds into fine particles, mineral sieve fractions, in particular for carrying out a process according to at least one of claims 1 to 15, comprehensive: a base (18) for placing a pile (1,8) of at least one sieve fraction on the base (18), a temperature measuring device (2) for measuring a temperature at a measuring point (4) within the stockpile (1), a drying device, in particular a drum sieve (6), for drying the stockpile (1).

17. Landfill facility (100) according to claim 16, further comprising: an exhaust air device (10) for extracting the air during of the dryness of the stockpile (1,8) and / or a biofilter (12) for cleaning the extracted air.

18. Landfill facility (100) according to claim 16 or 17, further comprising: a roof (16) for arranging the Pile of material (1.8) below the roof (16).

19. Landfill facility (100) according to at least one of claims 16 to 18, further comprising: at least one conveyor belt and / or vehicle (20) for loading and transporting bulk goods, in particular a Sieve fraction.