CA2259943A1 - Method for optimizing and improving the space load of fermentation reactors - Google Patents
Method for optimizing and improving the space load of fermentation reactors Download PDFInfo
- Publication number
- CA2259943A1 CA2259943A1 CA002259943A CA2259943A CA2259943A1 CA 2259943 A1 CA2259943 A1 CA 2259943A1 CA 002259943 A CA002259943 A CA 002259943A CA 2259943 A CA2259943 A CA 2259943A CA 2259943 A1 CA2259943 A1 CA 2259943A1
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- Canada
- Prior art keywords
- sludges
- process according
- fermentation
- thickening
- sludge
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09B—DISPOSAL OF SOLID WASTE
- B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/02—Biological treatment
- C02F11/04—Anaerobic treatment; Production of methane by such processes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/123—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using belt or band filters
Abstract
The invention relates to a method for thickening slimes containing biogenous organic substances, characterized in that the slimes are thickened mechanically before fermentation in order to improve the dry substance concentration of said slimes.
Description
CA 022~9943 1999-01-08 "METHOD FOR OPTIMIZING AND IMPROVING THE SPA OE LOAD OF
FERMEN~ATION REACTORS"
The present invention relates to a process for increasing the organic loading per unit volume of fermen-S tation reactors which are used for the anaerobic bio-logical stabilization of sludges having biogenic/organic constituents.
Anaerobic treatment ~fermentation) is very frequently used in the disposal sector for the biological stabilization of sludges having biogenic/organic con-stituents. The most important areas of use of fermen-tation technology include the treatment of sewage sludges as a process step in municipal or industrial waste water clean up, waste treatment and the treatment of material streams from the agricultural sector (liquid manure).
In waste fermentation, suitable starting materials are, in particular, domestic and industrial refuse, biowaste from the separate municipal collection of domestic refuse and organic industrial wastes, such as wastes from the production of food, drinks and stimu-lants, or food waste from large-scale kitchens and canteens. In order to make it possible to process these wastes in the fermentation stage, in numerous treatment processes, a preparation stage is provided upstream of the fermentation with the aim of comminuting, homogen-izing and separating off non-biodegradable waste con-stituents, e.g. plastics, glass, metals. For this pur-pose, the waste is admixed with process water or utility water in a mixing or dispersion vessel (waste pulper), to prepare a sludge from which interfering compounds can be removed by float/sink separation. The shear forces acting during mixing of the waste sludge also produce a gentle selective defibration and comminution of fermentable organic waste constituents. The water content of the wastes is increased by this wet preparation technique and set to about 92-95~.
Similarly high water contents are exhibited by the sewage sludges produced during waste water puri-CA 022~9943 1999-01-08 fication and also the liquid manures produced during pig and cattle husbandry.
It is customary also to treat mixtures of the described sludges in what are termed cofermentation plants. In this manner, the microbiological degradation processes can be optimized with respect to nutrient supply and problems in monobatch treatment can be prevented. Here, for example, there is the possibility of processing sludges from the waste treatment together with sewage sludge in the rotting towers of municipal sewage treatment plants. The joint anaerobic treatment of liquid manure together with organic industrial wastes (food wastes, fat separater wastes, slaughterhouse wastes, etc.) and/or municipal biowastes is also very frequently practiced. In both applications, when wastes are pro-cessed in conjunction, an appropriate preparation tech-nique is necessary. The advantage in the operation of cofermentation plants is the shared use of existing infrastructure and the improvement of the degradation properties of the sludges.
The sludges and liquid manures described are conventionally fed to a fermentation reactor without further pretreatment. The reactor volume required for the fermentation is determined by the organic loading per unit volume and the hydraulic dwell time. In order to achieve a sufficiently high degree of degradation, a minimum dwell time in the fermentation reactor is neces-sary, which is customarily between 10 and 21 days.
Reducing the minimum dwell time below 10 days would be accompanied by a higher loading per unit volume and thus an unsatisfactory biological stabilization and higher residual organic loading of the rotted sludge, so that the downstream process stages such as composting or waste water purification would have to be designed for the degradation of a higher organic loading. A reduction of the minimum dwell time in the fermentation reactor is thus burdened with difficulties, so that to date, high reactor volumes with the abovementioned minimum dwell times being maintained are necessary.
-- . . . .
CA 022~9943 1999-01-08 Since, however, the economic efficiency of a fermentation process is critically determined by the reactor volume required, a decrease would be favorable with respect to minimizing the capital costs. The elec-trical energy requirements of the plant, e.g. for mixingor circulation of the reactor contents, could also be considerably reduced in the event of a decrease.
The object of the present invention is thus to achieve an increase in the organic loading per unit volume in the fermentation reactor with the same hydraulic dwell time.
This object is achieved according to the inven-tion by means of the fact that the water content of the sludges to be fermented is reduced prior to entry into the fermentation reactor, in order by this means to decrease the sludge volume to be treated per unit time.
Owing to the increase in the dry matter concentration, with the same hydraulic dwell time, the organic loading per unit volume of the fermentation reactor is increased.
This increase in the organic loading per unit volume can be augmented up to a maximum value dependent on the fermentation system without adverse effects being pro-duced by this means on the stabilization process, i.e. on the degree of degradation which can be achieved.
The present invention thus relates to a process for the thickening of sludges having biogenic/organic constituents, characterized in that the sludges, prior to their fermentation, are subjected to a mechanical thick-ening in order to increase the dry matter concentration of the sludge. The dry matter concentration is usually 1-9~, expediently 3-8~, preferably 5-8~. The thickening removes water from the sludge and sets its dry matter content to a desired value which makes possible optimum organic loading per unit volume in the fermentation reactor. According to the invention, the dry matter concentration is usually set to a value of 10-15%, expediently 10-13~, preferably 11-13~. Various processes can be used for the sludge thickening, such as screen dewatering systems, presses (e.g. screw presses), CA 022~9943 1999-01-08 , decanters or centrifuges.
The sludges used in the process according to the invention can originate from waste water treatment (sewage sludge) or waste treatment, or from agricultural production (liquid manure).
By way of example, the process design of the thickening of a sludge may be shown below for the example of a sludge produced from wastes, preferably biowastes.
The wet treatment of the wastes, preferably the bio-wastes, can be performed in this case according to thedesign implemented in the BTA process. Figure 1 shows the possible process sequence in the form of a block diagram.
The waste originating, for example, from munici-pal or industrial sources is, after optionally separating off metallic constituents, e.g. of ferrous metals, by means of a metal separator is first loosened and gently comminuted in a bag separator, for example a mill, plastic and paper bags being shredded. The precomminuted untreated refuse then passes into a suspension vessel, for example into a waste pulper, in which it is admixed with water and exposed to shear forces in order to produce a crude suspension. It is preferred in this case to set the crude suspension to a dry matter concentration of 5-9~, in particular 7-9~. The interfering substances present in the biowaste can be removed by float/sink separation. In order to ensure removal of interfering substances which is as efficient as possible and free of organics, and with regard to minimum electrical energy input, setting higher dry matter concentrations is not desirable. The organic-containing sludge, which customarily has a particle size of up to 25 mm, is pumped into a collection vessel at the bottom of the vessel.
Inert constituents still present in the sludge, such as sand, glass splinters, stones, can, for example, be removed by a hydrocyclone, with a conjoint use of flushing water, in the context of removal of inert substances. The flushing water required for this process leads to a further decrease of the dry matter concentration of the sludge to customarily 3-8~, CA 022~9943 1999-01-08 .
preferably 5-8~. The resulting sludge is then fed to the further process stages.
Optionally, the resulting sludge can then be subjected to physicochemical treatment under alkaline conditions and at elevated temperature. This serves to increase the fermentability in the case of certain refuse types.
Subsequently, the resulting sludge can be sub-jected to a solid-liquid separation, in which it is separated (two-stage process) into a liquid stream and a solid stream, or it can be fed directly (single-stage process) to a sludge reservoir or collection vessel for subsequent fermentation. In the two-stage process, the liquid stream is transferred to a sludge reservoir or a collection vessel for subsequent fermentation. The solid stream, if appropriate after a hydrolysis and subsequent repeated removal of the liquid portion resulting in the hydrolysis, is fed to an aerobic secondary digestion.
Usually, in the fermentation reactor, owing to the microbiological degradation of the organic dry matter, an equilibrium concentration of 2-5% is estab-lished. Experience with reactors shows that, for the fermentation, dry matter concentrations of at least 8% do not represent a problem, however. For this reason, according to the invention, the sludge is mechanically thickened prior to entry into the reactor, in order to increase the dry matter concentration of the sludge. The dry matter concentration of the sludge obtained from the upstream process stages is usually 1-8~, expediently 3-7%, preferably 5-7%. Owing to the thickening, water is taken off from the sludge and its dry matter content is set to a desired value, which makes optimum organic loading per unit volume possible in the fermentation reactor. According to the invention, the dry matter concentration is usually set to a value of 10-15~, expediently 10-13%, preferably 11-13%. Various processes can be used for the sludge thickening, such as screen dewatering systems, presses (e.g. screw presses), decanters or centrifuges. If appropriate, in addition, a CA 022~9943 1999-01-08 sanitation apparatus can be connected upstream of the fermentation reactor in order to ensure freedom from pathogens of the end product of the fermentation process (fermentation residue). The sanitation step inactivates bacteria, fungi, viruses and weed seeds. This can be achieved, for example, by treatment in a sanitation apparatus (e.g. heating temperature 70~C, dwell time 30 min). Sanitation can be carried out before or after thickening, preferably after thickening. The advantage of sanitation after thickening is that smaller systems and less energy are required in this case because of the smaller stream.
Thickening using a screen dewatering machine is described below as an example.
The sludge in this process is pumped from the collection vessel or sludge reservoir, for example, to the screen dewatering machine. The degree of thickening achievable may be determined, for example, from the amount of added coagulation aid. In addition to the amount of coagulation aid, the degree of thickening can also be influenced, for example, by the screening rate.
However, in this case, care must be taken not to set a maximum DM content of the sludge, but a DM content which is necessary for the optimum organic loading per unit volume of the reactor. This is, for example, for the design presented here, preferably approximately 6-7 kg of organic dry residue/(m3*d). In order to be able to set this value in the reactor, thickening of the sludge to expediently 10-13~ DM is necessary.
The sludge, admixed for example with coagulation aid, proceeds along a horizontal dewatering section through a continuously rotating screen. On the screen chicanes may be located to improve the thickening effect and to prevent a moisture layer on the surface. Solids are retained on the screen and are fed via a hold-up ramp to the fermentation reactor. The clarified water produced is collected in an intermediate reservoir. Analogously to the thickening using a screen dewatering machine, thick-ening can also be carried out in a similar manner using CA 022~9943 1999-01-08 a screw press, a decanter or a centrifuge.
It is critical that the sludge is thickened in the context of the process according to the invention prior to the fermentation in order to increase the dry matter concentration of the sludge. The water produced as by-product in this case, termed clarified water below, can, in a preferred embodiment, be used for mixing the biowastes in the waste pulper, so that a water circula-tion is produced. The clarified water, furthermore, can be used in a further preferred embodiment as flushing water for the dewatering apparatus, for example the screen belt of the screen dewatering apparatus. Further-more clarified water, in a further preferred embodiment, owing to its high, readily degradable chemical oxygen demand (COD) can be added as required as a carbon source to a denitrification plant connected downstream of~the fermentation. As a result of this measure, addition of external carbon sources can be avoided. The uses of the clarified water represented as preferred embodiments in the context of the overall process may also be combined in any manner.
Subsequently, the sludge having an increased dry matter concentration is fed to an anaerobic fermentation.
Experiments have found that, in the case of sludges having an increased dry matter concentration of, for example, 10-14%, a markedly higher organic loading per unit volume in the fermentation reactor is achieved.
In an experiment carried out according to the invention, the biowaste suspension had a dry residue content of 8.7~. The loss on ignition was 75%. The thickened suspension had a dry residue content of 13.7%
and a loss on ignition of 77%. Thickening thus makes possible an increase in the organic loading per unit volume by 60-65% with the same hydraulic dwell time of 14 days in the fermentation reactor. The consumption of coagulation aids was 0.8-1 g/kg of DM.
The biogas produced in the fermentation can be supplied for further utilization, after it is taken off from the fermentation reactor. In addition, the effluent produced as a further product can, in a similar manner to the clarified water produced during thickening, also be reused in the process for the same purposes.
~ . . ~ . - . . . . . .
FERMEN~ATION REACTORS"
The present invention relates to a process for increasing the organic loading per unit volume of fermen-S tation reactors which are used for the anaerobic bio-logical stabilization of sludges having biogenic/organic constituents.
Anaerobic treatment ~fermentation) is very frequently used in the disposal sector for the biological stabilization of sludges having biogenic/organic con-stituents. The most important areas of use of fermen-tation technology include the treatment of sewage sludges as a process step in municipal or industrial waste water clean up, waste treatment and the treatment of material streams from the agricultural sector (liquid manure).
In waste fermentation, suitable starting materials are, in particular, domestic and industrial refuse, biowaste from the separate municipal collection of domestic refuse and organic industrial wastes, such as wastes from the production of food, drinks and stimu-lants, or food waste from large-scale kitchens and canteens. In order to make it possible to process these wastes in the fermentation stage, in numerous treatment processes, a preparation stage is provided upstream of the fermentation with the aim of comminuting, homogen-izing and separating off non-biodegradable waste con-stituents, e.g. plastics, glass, metals. For this pur-pose, the waste is admixed with process water or utility water in a mixing or dispersion vessel (waste pulper), to prepare a sludge from which interfering compounds can be removed by float/sink separation. The shear forces acting during mixing of the waste sludge also produce a gentle selective defibration and comminution of fermentable organic waste constituents. The water content of the wastes is increased by this wet preparation technique and set to about 92-95~.
Similarly high water contents are exhibited by the sewage sludges produced during waste water puri-CA 022~9943 1999-01-08 fication and also the liquid manures produced during pig and cattle husbandry.
It is customary also to treat mixtures of the described sludges in what are termed cofermentation plants. In this manner, the microbiological degradation processes can be optimized with respect to nutrient supply and problems in monobatch treatment can be prevented. Here, for example, there is the possibility of processing sludges from the waste treatment together with sewage sludge in the rotting towers of municipal sewage treatment plants. The joint anaerobic treatment of liquid manure together with organic industrial wastes (food wastes, fat separater wastes, slaughterhouse wastes, etc.) and/or municipal biowastes is also very frequently practiced. In both applications, when wastes are pro-cessed in conjunction, an appropriate preparation tech-nique is necessary. The advantage in the operation of cofermentation plants is the shared use of existing infrastructure and the improvement of the degradation properties of the sludges.
The sludges and liquid manures described are conventionally fed to a fermentation reactor without further pretreatment. The reactor volume required for the fermentation is determined by the organic loading per unit volume and the hydraulic dwell time. In order to achieve a sufficiently high degree of degradation, a minimum dwell time in the fermentation reactor is neces-sary, which is customarily between 10 and 21 days.
Reducing the minimum dwell time below 10 days would be accompanied by a higher loading per unit volume and thus an unsatisfactory biological stabilization and higher residual organic loading of the rotted sludge, so that the downstream process stages such as composting or waste water purification would have to be designed for the degradation of a higher organic loading. A reduction of the minimum dwell time in the fermentation reactor is thus burdened with difficulties, so that to date, high reactor volumes with the abovementioned minimum dwell times being maintained are necessary.
-- . . . .
CA 022~9943 1999-01-08 Since, however, the economic efficiency of a fermentation process is critically determined by the reactor volume required, a decrease would be favorable with respect to minimizing the capital costs. The elec-trical energy requirements of the plant, e.g. for mixingor circulation of the reactor contents, could also be considerably reduced in the event of a decrease.
The object of the present invention is thus to achieve an increase in the organic loading per unit volume in the fermentation reactor with the same hydraulic dwell time.
This object is achieved according to the inven-tion by means of the fact that the water content of the sludges to be fermented is reduced prior to entry into the fermentation reactor, in order by this means to decrease the sludge volume to be treated per unit time.
Owing to the increase in the dry matter concentration, with the same hydraulic dwell time, the organic loading per unit volume of the fermentation reactor is increased.
This increase in the organic loading per unit volume can be augmented up to a maximum value dependent on the fermentation system without adverse effects being pro-duced by this means on the stabilization process, i.e. on the degree of degradation which can be achieved.
The present invention thus relates to a process for the thickening of sludges having biogenic/organic constituents, characterized in that the sludges, prior to their fermentation, are subjected to a mechanical thick-ening in order to increase the dry matter concentration of the sludge. The dry matter concentration is usually 1-9~, expediently 3-8~, preferably 5-8~. The thickening removes water from the sludge and sets its dry matter content to a desired value which makes possible optimum organic loading per unit volume in the fermentation reactor. According to the invention, the dry matter concentration is usually set to a value of 10-15%, expediently 10-13~, preferably 11-13~. Various processes can be used for the sludge thickening, such as screen dewatering systems, presses (e.g. screw presses), CA 022~9943 1999-01-08 , decanters or centrifuges.
The sludges used in the process according to the invention can originate from waste water treatment (sewage sludge) or waste treatment, or from agricultural production (liquid manure).
By way of example, the process design of the thickening of a sludge may be shown below for the example of a sludge produced from wastes, preferably biowastes.
The wet treatment of the wastes, preferably the bio-wastes, can be performed in this case according to thedesign implemented in the BTA process. Figure 1 shows the possible process sequence in the form of a block diagram.
The waste originating, for example, from munici-pal or industrial sources is, after optionally separating off metallic constituents, e.g. of ferrous metals, by means of a metal separator is first loosened and gently comminuted in a bag separator, for example a mill, plastic and paper bags being shredded. The precomminuted untreated refuse then passes into a suspension vessel, for example into a waste pulper, in which it is admixed with water and exposed to shear forces in order to produce a crude suspension. It is preferred in this case to set the crude suspension to a dry matter concentration of 5-9~, in particular 7-9~. The interfering substances present in the biowaste can be removed by float/sink separation. In order to ensure removal of interfering substances which is as efficient as possible and free of organics, and with regard to minimum electrical energy input, setting higher dry matter concentrations is not desirable. The organic-containing sludge, which customarily has a particle size of up to 25 mm, is pumped into a collection vessel at the bottom of the vessel.
Inert constituents still present in the sludge, such as sand, glass splinters, stones, can, for example, be removed by a hydrocyclone, with a conjoint use of flushing water, in the context of removal of inert substances. The flushing water required for this process leads to a further decrease of the dry matter concentration of the sludge to customarily 3-8~, CA 022~9943 1999-01-08 .
preferably 5-8~. The resulting sludge is then fed to the further process stages.
Optionally, the resulting sludge can then be subjected to physicochemical treatment under alkaline conditions and at elevated temperature. This serves to increase the fermentability in the case of certain refuse types.
Subsequently, the resulting sludge can be sub-jected to a solid-liquid separation, in which it is separated (two-stage process) into a liquid stream and a solid stream, or it can be fed directly (single-stage process) to a sludge reservoir or collection vessel for subsequent fermentation. In the two-stage process, the liquid stream is transferred to a sludge reservoir or a collection vessel for subsequent fermentation. The solid stream, if appropriate after a hydrolysis and subsequent repeated removal of the liquid portion resulting in the hydrolysis, is fed to an aerobic secondary digestion.
Usually, in the fermentation reactor, owing to the microbiological degradation of the organic dry matter, an equilibrium concentration of 2-5% is estab-lished. Experience with reactors shows that, for the fermentation, dry matter concentrations of at least 8% do not represent a problem, however. For this reason, according to the invention, the sludge is mechanically thickened prior to entry into the reactor, in order to increase the dry matter concentration of the sludge. The dry matter concentration of the sludge obtained from the upstream process stages is usually 1-8~, expediently 3-7%, preferably 5-7%. Owing to the thickening, water is taken off from the sludge and its dry matter content is set to a desired value, which makes optimum organic loading per unit volume possible in the fermentation reactor. According to the invention, the dry matter concentration is usually set to a value of 10-15~, expediently 10-13%, preferably 11-13%. Various processes can be used for the sludge thickening, such as screen dewatering systems, presses (e.g. screw presses), decanters or centrifuges. If appropriate, in addition, a CA 022~9943 1999-01-08 sanitation apparatus can be connected upstream of the fermentation reactor in order to ensure freedom from pathogens of the end product of the fermentation process (fermentation residue). The sanitation step inactivates bacteria, fungi, viruses and weed seeds. This can be achieved, for example, by treatment in a sanitation apparatus (e.g. heating temperature 70~C, dwell time 30 min). Sanitation can be carried out before or after thickening, preferably after thickening. The advantage of sanitation after thickening is that smaller systems and less energy are required in this case because of the smaller stream.
Thickening using a screen dewatering machine is described below as an example.
The sludge in this process is pumped from the collection vessel or sludge reservoir, for example, to the screen dewatering machine. The degree of thickening achievable may be determined, for example, from the amount of added coagulation aid. In addition to the amount of coagulation aid, the degree of thickening can also be influenced, for example, by the screening rate.
However, in this case, care must be taken not to set a maximum DM content of the sludge, but a DM content which is necessary for the optimum organic loading per unit volume of the reactor. This is, for example, for the design presented here, preferably approximately 6-7 kg of organic dry residue/(m3*d). In order to be able to set this value in the reactor, thickening of the sludge to expediently 10-13~ DM is necessary.
The sludge, admixed for example with coagulation aid, proceeds along a horizontal dewatering section through a continuously rotating screen. On the screen chicanes may be located to improve the thickening effect and to prevent a moisture layer on the surface. Solids are retained on the screen and are fed via a hold-up ramp to the fermentation reactor. The clarified water produced is collected in an intermediate reservoir. Analogously to the thickening using a screen dewatering machine, thick-ening can also be carried out in a similar manner using CA 022~9943 1999-01-08 a screw press, a decanter or a centrifuge.
It is critical that the sludge is thickened in the context of the process according to the invention prior to the fermentation in order to increase the dry matter concentration of the sludge. The water produced as by-product in this case, termed clarified water below, can, in a preferred embodiment, be used for mixing the biowastes in the waste pulper, so that a water circula-tion is produced. The clarified water, furthermore, can be used in a further preferred embodiment as flushing water for the dewatering apparatus, for example the screen belt of the screen dewatering apparatus. Further-more clarified water, in a further preferred embodiment, owing to its high, readily degradable chemical oxygen demand (COD) can be added as required as a carbon source to a denitrification plant connected downstream of~the fermentation. As a result of this measure, addition of external carbon sources can be avoided. The uses of the clarified water represented as preferred embodiments in the context of the overall process may also be combined in any manner.
Subsequently, the sludge having an increased dry matter concentration is fed to an anaerobic fermentation.
Experiments have found that, in the case of sludges having an increased dry matter concentration of, for example, 10-14%, a markedly higher organic loading per unit volume in the fermentation reactor is achieved.
In an experiment carried out according to the invention, the biowaste suspension had a dry residue content of 8.7~. The loss on ignition was 75%. The thickened suspension had a dry residue content of 13.7%
and a loss on ignition of 77%. Thickening thus makes possible an increase in the organic loading per unit volume by 60-65% with the same hydraulic dwell time of 14 days in the fermentation reactor. The consumption of coagulation aids was 0.8-1 g/kg of DM.
The biogas produced in the fermentation can be supplied for further utilization, after it is taken off from the fermentation reactor. In addition, the effluent produced as a further product can, in a similar manner to the clarified water produced during thickening, also be reused in the process for the same purposes.
~ . . ~ . - . . . . . .
Claims (10)
1. Process for thickening sludges having biogenic/organic constituents, characterized in that the sludges, prior to their fermentation, are subjected to a mechanical thickening in order to increase the dry matter concentration of the sludge.
2. Process according to claim 1, characterized in that the sludges originate from waste water treatment (sewage sludge) or waste treatment, or from agricultural production (liquid manure).
3. Process according to claim 2, characterized in that the mixed sludges of different origin are thickened and fed to the fermentation.
4. Process according to one of claims 1 to 3, characterized in that the mechanical thickening of the sludges is performed by screen dewatering, centrifuging, decanting, extrusion or filtration.
5. Process according to one of the preceding claims, characterized in that the sludges originate from wastes produced by a wet preparation.
6. Process according to one of the preceding claims, characterized in that clarified water produced in the thickening is used as process water and flushing water for producing waste sludges in the wet preparation.
7. Process according to one of the preceding claims, characterized in that clarified water produced in the thickening is used as a carbon source carrier in a biological waste water treatment plant.
8. Process according to one of the preceding claims, characterized in that the thickened sludges are treated in a single- or multistage fermentation plant.
9. Process according to one of the preceding claims, characterized in that the thickened sludges are fed to a hydrolysis stage.
10. Process according to one of the preceding claims, characterized in that the thickened sludges, prior to the fermentation or hydrolysis, pass through a thermal treatment step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19719895A DE19719895C1 (en) | 1997-05-12 | 1997-05-12 | Process for optimizing and increasing the space load of fermentation reactors |
| DE19719895.3 | 1997-05-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2259943A1 true CA2259943A1 (en) | 1998-11-19 |
Family
ID=7829258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002259943A Abandoned CA2259943A1 (en) | 1997-05-12 | 1998-05-11 | Method for optimizing and improving the space load of fermentation reactors |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0878447A1 (en) |
| JP (1) | JP2000514714A (en) |
| AU (1) | AU7653798A (en) |
| CA (1) | CA2259943A1 (en) |
| DE (1) | DE19719895C1 (en) |
| WO (1) | WO1998051629A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10046389A1 (en) * | 2000-09-20 | 2002-04-04 | Farmatic Biotech Energy Ag | Disposal of slaughterhouse animal wastes comprises chopping and mixing wastes with organic residues to a defined ratio of dry matter to liquid, useful for energy generation |
| DE10108495A1 (en) * | 2001-02-22 | 2002-08-29 | Sbm Maschinen Gmbh | Biological kitchen waste disposal unit has intermediate buffer tank, located between feed unit and liquids-solids separator, which contains enzymes or bacteria to break down waste |
| DE102004054468A1 (en) * | 2004-11-11 | 2006-05-24 | Rösing, Gerhard, Dr. | Anaerobic fermentation of vegetable substrates for production of bio gas, comprises extruding substrates to form high-grade homogenized biomass by double escargots extrude, and growing nutrient for mead producer by biogenous material |
| DE102006010449A1 (en) * | 2006-03-03 | 2007-09-13 | Getproject Gmbh & Co. Kg | Process for the separation of biomass |
| ITMC20080135A1 (en) * | 2008-07-22 | 2010-01-23 | Nuova Maip Macchine Agric | SYSTEM OF TREATMENT OF SLUDGE COMING FROM WASTEWATER AND ITS ENERGY EXPLOITATION FOR COGENERATION. |
| IT1393315B1 (en) * | 2008-10-30 | 2012-04-20 | Pianese | PROCESS FOR THE TRANSFORMATION OF URBAN SOLID WASTE IN MATERIALS AND / OR CONGLOMERATED FROM THE INERT QUOTA, IN ENERGY OBTAINED BY THE BIOGAS DERIVING FROM COLD TREATMENT OF ANAEROBIC BIO-CONVERSION OF ORGANIC FRACTION AND IN POSSIBLE FINISHING |
| CN102574172B (en) * | 2009-09-22 | 2015-09-02 | 麦希利·迪尼施·钱德拉特里 | Comprise the system and method for the biological treatment of the biodegradable waste of biodegradable MSW |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1806275A1 (en) * | 1968-10-31 | 1970-04-23 | Metallgesellschaft Ag | Sewage sludge treatment and digestion |
| US4388186A (en) * | 1980-03-07 | 1983-06-14 | Kubota Ltd. | Sludge treating apparatus |
| DE3534603A1 (en) * | 1985-09-27 | 1987-04-09 | Boehnke Botho | Process for the further processing of raw sludge taken off from a biological waste water (effluent) purification plant |
| DE3614865A1 (en) * | 1986-05-02 | 1987-11-05 | Kraemer Paul | Device for sludge treatment |
| GB2220411B (en) * | 1988-03-30 | 1992-01-08 | Yoshio Kobayashi | Anaerobic digestion process for sewage sludge |
| DE4403589A1 (en) * | 1994-02-05 | 1995-08-10 | Norbert Ahlfaenger | Disposal of organic waste, esp. food |
| DE19540450A1 (en) * | 1995-01-11 | 1996-07-18 | Dyckerhoff & Widmann Ag | Treatment of raw sewage sludge to give prod. with high energy value |
-
1997
- 1997-05-12 DE DE19719895A patent/DE19719895C1/en not_active Expired - Fee Related
-
1998
- 1998-05-11 AU AU76537/98A patent/AU7653798A/en not_active Abandoned
- 1998-05-11 WO PCT/EP1998/002748 patent/WO1998051629A1/en active Application Filing
- 1998-05-11 EP EP98108553A patent/EP0878447A1/en not_active Withdrawn
- 1998-05-11 JP JP10548789A patent/JP2000514714A/en active Pending
- 1998-05-11 CA CA002259943A patent/CA2259943A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| AU7653798A (en) | 1998-12-08 |
| EP0878447A1 (en) | 1998-11-18 |
| WO1998051629A1 (en) | 1998-11-19 |
| JP2000514714A (en) | 2000-11-07 |
| DE19719895C1 (en) | 1998-11-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |