CA2127393A1 - Method and apparatus for composting organic substances, in particular waste material - Google Patents
Method and apparatus for composting organic substances, in particular waste materialInfo
- Publication number
- CA2127393A1 CA2127393A1 CA002127393A CA2127393A CA2127393A1 CA 2127393 A1 CA2127393 A1 CA 2127393A1 CA 002127393 A CA002127393 A CA 002127393A CA 2127393 A CA2127393 A CA 2127393A CA 2127393 A1 CA2127393 A1 CA 2127393A1
- Authority
- CA
- Canada
- Prior art keywords
- exhaust air
- air
- rotting material
- rotting
- foregoing
- Prior art date
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
- C05F17/00—Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation
- C05F17/70—Controlling the treatment in response to process parameters
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
- C05F17/00—Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation
- C05F17/60—Heating or cooling during the treatment
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
- C05F17/00—Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation
- C05F17/90—Apparatus therefor
- C05F17/964—Constructional parts, e.g. floors, covers or doors
- C05F17/971—Constructional parts, e.g. floors, covers or doors for feeding or discharging materials to be treated; for feeding or discharging other material
- C05F17/979—Constructional parts, e.g. floors, covers or doors for feeding or discharging materials to be treated; for feeding or discharging other material the other material being gaseous
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/141—Feedstock
- Y02P20/145—Feedstock the feedstock being materials of biological origin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/40—Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Biotechnology (AREA)
- Health & Medical Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Microbiology (AREA)
- Molecular Biology (AREA)
- Organic Chemistry (AREA)
- Fertilizers (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Abstract of the Disclosure A method is used for the composting of organic substances (rotting material), in particular waste material, for instance household garbage or garbage similar to household garbage. The rotting material is put into a closed container and is decomposed microbially by supplying oxygen thereto. To the rotting material there is furthermore also supplied a mixture of pure oxygen and exhaust air. In order to improve such a method, CO2 as contained in the exhaust air is refed to the rotting material. The water which is contained in the exhaust air escaping from the rotting material is separated.
Description
21~7393 METHOD AND APPARATUS FOR COMPOSTING ORGANIC SUBSTANCE8, _ . . . . . _ _ IN PARTICULAR WAS~E MATERIAL
The invention refers to a method for compostlng organlc substances ~waste material to be rotted, i.e. rottlng materlal), in particular waste material, for lnstance household garbage or garbage similar to household garbage, in which the rotting material is fed into a closed container and is decomposed microbially by supplying oxygen thereto, the -rotting material being furthermore supplied with a mixture of pure oxygen and used air (exhaust air), and also refers to an apparatus for carrying out said method.
A method for composting organic substances, in particular waste material, for instance household garbage or garbage -~
similar to household garbage, in which the rotting material is -~
fed into a closed container and decomposed microbially by -adding oxygen, is ~nown from German Patent Specification 36 37 -393 to which reference is explicltly made herewith and the content of which is to be incorporated in the present - ~
application. In the known method, household garbage or waste - -material similar to household garbage ls fed into a closed container and then decomposed by means of an air supply adapted to the microbial growth without moving the waste material. In the container there are provided bottom plates permeable to air below which there is a supply air channel. In the upper section of the container there is provided a used air opening. The rotting material lying on the bottom plates is provided with fresh air from below. To this end there are provided fans in the channel below the bottom plates. The exhaust air escaping from the rotting material at the top and comprising C02 and water is drawn off through the used air ~ 2127333 opening. Then said used air is filtered and purified.
In the known method, normal air is guided through the rottlng material. Apart from oxygen required for the rotting process there is also led a considerable amount of nitrogen through the rotting material so that also a very large amount of used air to be exhausted is produced. Consequently the blower capacity which must be installed and operated must be very high. Furthermore there is produced a large amount of exhaust air which is given off into the atmosphere and which must be filtered and purified beforehand so that no or only a very low environmental impact, in particular annoyance caused by bad smell, will occur.
In order to allow for a reduction of the blower capacity, it ~ -has already been proposed to only work with pure oxygen.
Accoxding thereto the rotting material is not provided with air with an oxygen content of approximately 21 % but with pure oxygen. But is has been found that then the fluidic conditions may change adversely. Furthermore, pure oxygen is relatively expensive so that the method is not economical when there is only used pure oxygen.
Proceeding therefrom, in German laid~open print 41 07 340 - to which also reference is made herewith and the content of which is also explicitly incorporated into the present application -a method of the above-mentioned kind, i.e. a method according to the generic part of claim 1 is proposed. Accordingly, a mixture of pure oxygen and exhaust air is supplied to the rotting material.
In German laid-open print 41 07 340 it is also proposed to separate C02 and water as contained in the exhaust air escaping from the rotting material.
By the fact that a mixture of pure oxygen and used air is supplied to the rotting material, the amount of gas to be passed through the rotting material is considerably reduced.
Whereas according to German patent specification 36 37 393 there was only used fresh air for the operation, according to German laid-open print 41 07 340 the exhaust gas is partially or completely circulated and there is a metered addition of ~-~
pure oxygen so that the amount of gas to be passed through the rotting material is substantially reduced relative to the ~ ~ -method according to German patent specification 36 37 393, which is advantageous in that the blower capacity to be ~
installed may be lower. Also the operating expenses for the ~---blowers are reduced. Hence, compared with the method according to German patent specification 36 37 393, there can be obtained quite a considerable saving in energy by the -~
method according to German laid-open print 41 07 340.
Moreover, also a considerable saving in the expenditure required for the filtering of the exhaust air may be obtalned.
According to the teaching of German laid-open print 41 07 340, a carrier air is added to the pure oxygen due to fluldic reasons. Said carrier air consists of the exhaust air escaping from the rotting material. Said carrier air is correspondingly circulated. The used air escaping from the rotting material is again supplied to the rotting material together with pure oxygen. This is carried out b~st in the manner as known from German patent specification 36 37 3g3, i.e. in that the oxygen/exhaust air mixture is supplied to the rotting material from below and that the exhaust air escaping from the rottlng material is led away at the top side of the rotting material.
``` 2127~J3 According to German laid-open print 41 07 340, the amount of air which is led in the circuit, i.e. is circulated, is calculated such that results satisfying under fluidic polnts of view may be obtained. The circulating air gulded ln the circulation system (circult) is dimensioned as low as possible, but also so large that a perfect flow and particularly a perfect removal of the C02 produced ln the ``~
rotting material are obtained. - -From German laid-open print 40 34 400 there is known a m~thod ~ ~
for the biotechnological treatment of a residual material -mixture (recyclings mixture) in which the residual material mixture is treated by a microbial transformation process in a closed system for the production of compost. The residual material mixture is mixed thoroughly by means of a drum in the closed system. According to an advantageous further development, from time to time a defined amount of fresh alr (outside air), pure oxygen or pure C02 may by supplied to the closed system and a corresponding exhaust air amount may be drawn thereoff preferably via a biofilter.
It is the object of the invention to improve the ;
above-indicated method.
According to the invention said object is solved in that the C2 contained in the used air is supplied once again to the rotting material and that from the exhaust air escaping from -the rotting material the water contained therein is separated.
According to the teaching of German laid-open print 41 07 340 the C2 contained in the used air escaping from the rotting material is separated. And this is carried out according to the teaching of German laid~open print 41 07 340 so that said ~`
C2 will not accumulate more and more in the circulated ~ ~
carrier air. According to former ideas as expressed in German laid-open print 41 07 340, C2 must be removed from the circulated carrier air. But surprisingly it showed that this is not necessary contrary to the hitherto prevailing conviction. This is advantageous in that the expenditure connected with the removal of C02 from the exhaust air can be economized according to the method of the invention.
Furthermore, the hitherto existing ideas have been based on the opinion that when there is an always higher C02 content the atmosphere for the microorganisms effecting the composting will be made worse which will lead to the fact that said microorganisms effecting the composting will work increasingly worse and finally will not work at all, i.e. cannot carry out the metabolic processes effecting the composting. But surprisingly it showed that the C2 accumulation occurring according to the method of the invention in the circulated air or in the circulated gases do not lead to the suspected disadvantages.
The amount of pure oxygen to be supplied is adjusted such that there is present sufficient oxygen for the rotting process. In the method according to the invention the rotting material in the container need not be moved, i.e. need not be circulated - ~-or rearranged. But the method according to the invention can also be used when such a movement, circulation or rearrangement of the rotting material takes place.
From the exhaust air escaping from the rotting material the water contained therein is separated. The biomass contained in the rotting material and consisting of carbon, hydrogen, oxygen as well as other elements, reacts with the added oxygen - "
-^` 2127393 in such a manner that the hydrogen forms water wlth the ~ -oxygen. Said water may then be separated and can then leave -the circuit. Besides, the exhaust air or the circulating air is guided in the circuit. With increasing duration of time, C2 accumulates in the circulating air. But despite a constant
The invention refers to a method for compostlng organlc substances ~waste material to be rotted, i.e. rottlng materlal), in particular waste material, for lnstance household garbage or garbage similar to household garbage, in which the rotting material is fed into a closed container and is decomposed microbially by supplying oxygen thereto, the -rotting material being furthermore supplied with a mixture of pure oxygen and used air (exhaust air), and also refers to an apparatus for carrying out said method.
A method for composting organic substances, in particular waste material, for instance household garbage or garbage -~
similar to household garbage, in which the rotting material is -~
fed into a closed container and decomposed microbially by -adding oxygen, is ~nown from German Patent Specification 36 37 -393 to which reference is explicltly made herewith and the content of which is to be incorporated in the present - ~
application. In the known method, household garbage or waste - -material similar to household garbage ls fed into a closed container and then decomposed by means of an air supply adapted to the microbial growth without moving the waste material. In the container there are provided bottom plates permeable to air below which there is a supply air channel. In the upper section of the container there is provided a used air opening. The rotting material lying on the bottom plates is provided with fresh air from below. To this end there are provided fans in the channel below the bottom plates. The exhaust air escaping from the rotting material at the top and comprising C02 and water is drawn off through the used air ~ 2127333 opening. Then said used air is filtered and purified.
In the known method, normal air is guided through the rottlng material. Apart from oxygen required for the rotting process there is also led a considerable amount of nitrogen through the rotting material so that also a very large amount of used air to be exhausted is produced. Consequently the blower capacity which must be installed and operated must be very high. Furthermore there is produced a large amount of exhaust air which is given off into the atmosphere and which must be filtered and purified beforehand so that no or only a very low environmental impact, in particular annoyance caused by bad smell, will occur.
In order to allow for a reduction of the blower capacity, it ~ -has already been proposed to only work with pure oxygen.
Accoxding thereto the rotting material is not provided with air with an oxygen content of approximately 21 % but with pure oxygen. But is has been found that then the fluidic conditions may change adversely. Furthermore, pure oxygen is relatively expensive so that the method is not economical when there is only used pure oxygen.
Proceeding therefrom, in German laid~open print 41 07 340 - to which also reference is made herewith and the content of which is also explicitly incorporated into the present application -a method of the above-mentioned kind, i.e. a method according to the generic part of claim 1 is proposed. Accordingly, a mixture of pure oxygen and exhaust air is supplied to the rotting material.
In German laid-open print 41 07 340 it is also proposed to separate C02 and water as contained in the exhaust air escaping from the rotting material.
By the fact that a mixture of pure oxygen and used air is supplied to the rotting material, the amount of gas to be passed through the rotting material is considerably reduced.
Whereas according to German patent specification 36 37 393 there was only used fresh air for the operation, according to German laid-open print 41 07 340 the exhaust gas is partially or completely circulated and there is a metered addition of ~-~
pure oxygen so that the amount of gas to be passed through the rotting material is substantially reduced relative to the ~ ~ -method according to German patent specification 36 37 393, which is advantageous in that the blower capacity to be ~
installed may be lower. Also the operating expenses for the ~---blowers are reduced. Hence, compared with the method according to German patent specification 36 37 393, there can be obtained quite a considerable saving in energy by the -~
method according to German laid-open print 41 07 340.
Moreover, also a considerable saving in the expenditure required for the filtering of the exhaust air may be obtalned.
According to the teaching of German laid-open print 41 07 340, a carrier air is added to the pure oxygen due to fluldic reasons. Said carrier air consists of the exhaust air escaping from the rotting material. Said carrier air is correspondingly circulated. The used air escaping from the rotting material is again supplied to the rotting material together with pure oxygen. This is carried out b~st in the manner as known from German patent specification 36 37 3g3, i.e. in that the oxygen/exhaust air mixture is supplied to the rotting material from below and that the exhaust air escaping from the rottlng material is led away at the top side of the rotting material.
``` 2127~J3 According to German laid-open print 41 07 340, the amount of air which is led in the circuit, i.e. is circulated, is calculated such that results satisfying under fluidic polnts of view may be obtained. The circulating air gulded ln the circulation system (circult) is dimensioned as low as possible, but also so large that a perfect flow and particularly a perfect removal of the C02 produced ln the ``~
rotting material are obtained. - -From German laid-open print 40 34 400 there is known a m~thod ~ ~
for the biotechnological treatment of a residual material -mixture (recyclings mixture) in which the residual material mixture is treated by a microbial transformation process in a closed system for the production of compost. The residual material mixture is mixed thoroughly by means of a drum in the closed system. According to an advantageous further development, from time to time a defined amount of fresh alr (outside air), pure oxygen or pure C02 may by supplied to the closed system and a corresponding exhaust air amount may be drawn thereoff preferably via a biofilter.
It is the object of the invention to improve the ;
above-indicated method.
According to the invention said object is solved in that the C2 contained in the used air is supplied once again to the rotting material and that from the exhaust air escaping from -the rotting material the water contained therein is separated.
According to the teaching of German laid-open print 41 07 340 the C2 contained in the used air escaping from the rotting material is separated. And this is carried out according to the teaching of German laid~open print 41 07 340 so that said ~`
C2 will not accumulate more and more in the circulated ~ ~
carrier air. According to former ideas as expressed in German laid-open print 41 07 340, C2 must be removed from the circulated carrier air. But surprisingly it showed that this is not necessary contrary to the hitherto prevailing conviction. This is advantageous in that the expenditure connected with the removal of C02 from the exhaust air can be economized according to the method of the invention.
Furthermore, the hitherto existing ideas have been based on the opinion that when there is an always higher C02 content the atmosphere for the microorganisms effecting the composting will be made worse which will lead to the fact that said microorganisms effecting the composting will work increasingly worse and finally will not work at all, i.e. cannot carry out the metabolic processes effecting the composting. But surprisingly it showed that the C2 accumulation occurring according to the method of the invention in the circulated air or in the circulated gases do not lead to the suspected disadvantages.
The amount of pure oxygen to be supplied is adjusted such that there is present sufficient oxygen for the rotting process. In the method according to the invention the rotting material in the container need not be moved, i.e. need not be circulated - ~-or rearranged. But the method according to the invention can also be used when such a movement, circulation or rearrangement of the rotting material takes place.
From the exhaust air escaping from the rotting material the water contained therein is separated. The biomass contained in the rotting material and consisting of carbon, hydrogen, oxygen as well as other elements, reacts with the added oxygen - "
-^` 2127393 in such a manner that the hydrogen forms water wlth the ~ -oxygen. Said water may then be separated and can then leave -the circuit. Besides, the exhaust air or the circulating air is guided in the circuit. With increasing duration of time, C2 accumulates in the circulating air. But despite a constant
2 supply the mass balance in the recirculating air condult remains constant, since water is equally discharged. Hence, lt is not necessary to also remove C2 from the circulation system. For maintaining the mass balance it is sufficient to only remove water from the circuit. Furthermore it surprisingly showed that the CO2 accumulation in the circulating air is not detrimental and that the rotting process is not adversely influenced thereby. Consequently, it is not necessary to remove the CO2. On the contrary, the -~
entire C2 can once again be supplied to the rotting materlal. -Consequently it is not necessary to remove exhaust air from the circuit. Only water is removed from the circuit, but nothing else. Thereby a particularly advantageous and simple method guidance is enabled. As there is no longer any exhaust air, an exhaust air purification is no longer necessary. -Advantageous further developments of the invention are ~ -described in the subclaims.
It is preferred to once again supply the exhaust air escaping from the rotting material completely to the rotting material.
This means that a complete circulating air guidance takes place. After the removal of the water contained therein, the entire exhaust air escaping from the rotting material is once again fed to the rotting material together with pure oxygen.
Consequently, the circulated exhaust air ("circulating air" or "carrier air") is completely circulated in the circulation system.
This is connected with the further advantage that no exhaust air at all must be discharged to the outside so that also a filterlng of the air is no longer necessary. The expenditure involved therewith is avoided. Environmental impact~, ln particular annoyance caused by bad smell, are already completely avoided in principle.
It is advantageous when the exhaust air escaping from the rotting material is contlnuously supplied again to the rottlng material. Consequently, the circula~ing air guidance is carried out during the entire duration of the process. It is not necessary to interrupt the circulating air guidance. It is also advantageous to continuously supply the oxygen. Also the supply of oxygen ls carried out during the entire duration of the process without any lnterruption.
According to another advantageous further development the amount of gas circulated per unit time is increased when the temperature in the rotting material increases. Accordingly it is advantageous that the amount of gas circulated per unit -~
time is reduced when the temperature in the rotting material decreases, and viceversa. The circulated amount of gas is the exhaust air leaving the container and and containing C02 and water, or the exhaust air containing C02 from which the water has been separated, if necessary.
A further advantageous development is characterized in that the content of moisture in the circulated gas is maintained constant at a certain predetermined value. It showed that then the method according to the invention can be carried out particularly good and effective.
-`` 2127393 The temperature in the container or in the rotting material is preferably at least 60C. If possible, the rotting process is to be carried out at a temperature which is so high that the pathogenous germs are killed and cannot work. This is typically the case at a temperature of at least 60C (with a reaction time of at least 12 hours). Consequently, the method is controlled such that said temperature of at least 60C wlll be reached. Then the decomposition of the organic substances by thermophile microorganisms, e.g. actinomycetes, is carried out which turned out to be advantageous. Typically the temperature in the container or in the rotting material lies between 60C and 80C. Said range of temperature is to be --maintained.
According to another advantageous further development the water contained in the used air is separated by cooling and condensation, preferably in a heat exchanger. The exhaust air -leaving the container may e.g. have a temperature of for --instance 45 to 80 when it reaches the heat exchanger. The exhaust air is cooled e.g. in a heat exchanger, in order to remove the water contained therein and produced in the container during the rotting process by condensation. The - : -exhaust air freed from the water contained therein in such a -~
manner is then once again fed to the container. Then it may have a temperature of for instance 20C. It is possible to -~
influence the extent of the cooling of the exhaust air, for instance by a respective control of the heat exchanger.
Thereby the temperature in the container (reactor) can be ~-influenced. When the exhaust air will only be cooled to a -minor extent in the heat exchanger, it is returned to the container with a higher temperature, whereby the temperature ~ -in the container and in the rotting material increases, or decreases to a minor extent. On the other hand, when the ;~
:~ ,::-.:
,.. , ,, . , , ,, . .. : ~ : ~ ,.
2127~3 g exhaust air is cooled to a greater extent, lt is returned to the container with a lower temperature, whereby the temperature in the container or in the rotting material is lowered, or increased to a minor extent.
Instead thereof or additionally thereto, the temperature in the container or in the rotting material may he influenced or controlled by the amount of gas circulated per unit time. When the amount of gas circulated pex unit time is increased, a larger cooling takes place in the rotting material. When, viceversa, the amount of gas circulated per unit time is -reduced, there is an increase in temperature in the rotting material.
When the rotting material still to be rotted (substrate) runs low after a predetermined time of for instance approximately seven days, i.e. when only a relatively small amount of rotting mat~rial to be composted is present, the amount of heat produced in the rotting material per unit time will decrease. This leads to the fact that also the temperature of -the rotting material is lowered. In order to be able to maintain the preferred temperature of at least 60C or of 60C
to 80~C, the above explained measures may b~ carried out individually or in common. Thus it is possible to cool the exhaust air to a minor extent and/or to lower the amount of gas circulated per unit time.
The point of time at wh$ch the substrate to be composted becomes less in the described manner is that point of time at which the organic parts of the waste material which are easier to be decomposed biologically have been decomposed in the sense of the German patent specification 36 37 393.
According to a further advantageous development energy, preferably electric energy is generated from the heat contained in the exhaust air. Here preferably the heat released during the condensation of the water contained ln the exhaust air is used. Said heat may preferably be conveyed via a heat exchanger to another medium which in turn may drive an engine. Said engine can produce electrical current. By the method according to the invention it is possible for the first time to produce such an amount of heat during the biological composting that said heat may then also be used for the production of mechanical energy. ~ecisive therefor is not only the produced amount of heat but also the temperature profile, i.e. the available difference in temperature. When the rotting material has a temperature between 60C and 80C, and when -~ -there is an ambient temperature of 20C, then there is available a temperature drop of 40C to 60C. The obtainable electric energy is sufficient to drive the blowers reguired for the air circulation. The energy produced in surplus ~ -thereof may be used for other purposes. Preferably said surplus electric energy may be used for the production of oxygen from the air. Preferably, said oxygen is supplied to -;~
the rotting material as pure oxygen.
A further advantageous development is characterized in that the amount of oxygen supplied per unit time is increased when the C2 content in the exhaust air or in the circulating air -~
or in the circulated gases increases. As already explained, ~-the C02 content in the exhaust air or in the circulating air raises in course of time, since no C2 is removed. For the compensation of said increasing C02 content the amount of supplied oxygen is raised. Preferably this is carried out proportional to the accumulation of the C02 content in the circulated gas. Consequently, the amount of oxygen supplied --- 2~27393 per unit time is preferably increased to the same extent as the C02 content in the circulated gas increases.
, According to the reaction equation C6H1206 + 602 a 6C02 + 6H20 + 674 kcal, half of the added oxygen is used for the production of water and the other half for the productlon of C02. The water can be separated, but it is not necessary. The formed C2 accumulates in the circulated gas. Thereby, i.e. by the increase of the mass in the closed system, also the pressure in the closed system is increased. Correspondingly, the output of the fans producing the circulating air guidance ~-may be increased in order to keep constant the amount of gas -circulated per unit time. But this is only true when the closed system is sufficiently tight. It is possible that minor leakages are present which prevent a pressure increase in the closed system, so that the fan output may remain identical.
By the invention the effectivity of the method is enormously increased. Said increase in effectivity is due to the fact that the biological energy release process which up to now has taken up a relatively large time, may now be carried out in a substantially shorter time period (which only amounts up to 1/4 to 1/3 of the time period required up to now). Thereby the output (composting output), i.e. the amount composted per unlt time is substantially increased. Furthermore also the usable energy release per unit time which can be used in the above described manner for the production of energy, i.e. the power (usable energy per time) is substantially larger and therefor economically interesting. -A further advantageous embodiment is characterized in that the exhaust gas is not filtered. Thereby the hitherto necessary expenditure involved therewith is avoided. It is possible to do without the exhaust air filtering, since the exhaust alr ls continuously and completely guided in the circuit, i.e.
circulated so that there is no exhaust air leaving the system which would have to be filtered. ~-, It is advantageous that the exhaust air is passed through a water bath which can be the condensate. Furthermore, the heat dissipated from the exhaust gas to the water bath may be preferably used by e.g. conveying said heat to a heat ~-exchanger. ~y the fact that the exhaust air is passed through -a water bath, the water present in the exhaust air may be -, .
removed from the exhaust air in a particularly simple and effective manner. By said process the exhaust air is cooled ;
and the water is condensed. The arrangements may me made such that the water bath is always given in the same amount. The water bath may for instance be realized as a water tank which --always has the same level. This can be easily realized ln that ~-in the tank there is provided an overflow and that the - --overflowing water is discharged.
The heat received by the water bath or the water tank may be dissipated, for instance via a circulation conduit with heat exchanger and/or cooling unit.
According to another advantageous development the exhaust ga is purified before the termination of the rotting process.
After the termination of the rotting process the closed container is opened, and the rotting material located therein and being at least in part composted, is removed from said container. Directly prior thereto the exhaust air or the air content of the closed container can be purified, in order to prevent an evading of the exhaust air into the atmosphere. In the course of said purification, in particular C2 may be : ~
removed from the air in order to avoid that after the opening of the closed container it escapes into the environment. The removal of CO2 may be carried out in a water bath with calcium oxide (CaO) or calcium hydroxide (CaOH). In the course of the purification there can also be removed ammonium, for instance ~-in a water bath with calcium hydrocarbonate or calcium hydrogen phosphate. The removal of ammonlum cannot only be carried out directly before the termination of the rotting process but also during the entire rotting process.
An apparatus for carrying out the method according to the invention consists of a closed container with an air supply means and an air discharge means through which the exhaust air can be once again supplied to the container. Furthermore there is provided an automatic aeration device which supplies the exhaust gas once again to the closed container. There may also be provided an oxygen supply means for supplying oxygen or pure oxygen, as well as a water discharge means for discharging the water removed from the exhaust air.
For the solution of the above-indicated ob~ect such an apparatus is characterized according to the invention in that no exhaust air filter is provided. As the exhaust air is completely circulated, no exhaust air leaving the system is present so that also no exhaust air filter is required.
An advantageous further development of the apparatus according to the invention is characterized in that in the air dlscharge means a water bath is provided through which the exhaust air may be passed. To the water bath or the water tank there is preferably supplied the condensate, i.e. the water removed from the exhaust air. The water tank may be provided with an overflow so that always the same water level is maintained ~..' ~' therein and that the overflowing water can always be removed.
A further advantageous development is characterized by a heat exchanger for dissipating the heat conveyed by the exhaust air to the water bath.
During operation, practically there takes place no change of pressure in the system. The system is always supplied wlth pure oxygen, but water is also always removed therefrom so that the entire volume of the system remains substantially identical and the pressure is practically not changed.
entire C2 can once again be supplied to the rotting materlal. -Consequently it is not necessary to remove exhaust air from the circuit. Only water is removed from the circuit, but nothing else. Thereby a particularly advantageous and simple method guidance is enabled. As there is no longer any exhaust air, an exhaust air purification is no longer necessary. -Advantageous further developments of the invention are ~ -described in the subclaims.
It is preferred to once again supply the exhaust air escaping from the rotting material completely to the rotting material.
This means that a complete circulating air guidance takes place. After the removal of the water contained therein, the entire exhaust air escaping from the rotting material is once again fed to the rotting material together with pure oxygen.
Consequently, the circulated exhaust air ("circulating air" or "carrier air") is completely circulated in the circulation system.
This is connected with the further advantage that no exhaust air at all must be discharged to the outside so that also a filterlng of the air is no longer necessary. The expenditure involved therewith is avoided. Environmental impact~, ln particular annoyance caused by bad smell, are already completely avoided in principle.
It is advantageous when the exhaust air escaping from the rotting material is contlnuously supplied again to the rottlng material. Consequently, the circula~ing air guidance is carried out during the entire duration of the process. It is not necessary to interrupt the circulating air guidance. It is also advantageous to continuously supply the oxygen. Also the supply of oxygen ls carried out during the entire duration of the process without any lnterruption.
According to another advantageous further development the amount of gas circulated per unit time is increased when the temperature in the rotting material increases. Accordingly it is advantageous that the amount of gas circulated per unit -~
time is reduced when the temperature in the rotting material decreases, and viceversa. The circulated amount of gas is the exhaust air leaving the container and and containing C02 and water, or the exhaust air containing C02 from which the water has been separated, if necessary.
A further advantageous development is characterized in that the content of moisture in the circulated gas is maintained constant at a certain predetermined value. It showed that then the method according to the invention can be carried out particularly good and effective.
-`` 2127393 The temperature in the container or in the rotting material is preferably at least 60C. If possible, the rotting process is to be carried out at a temperature which is so high that the pathogenous germs are killed and cannot work. This is typically the case at a temperature of at least 60C (with a reaction time of at least 12 hours). Consequently, the method is controlled such that said temperature of at least 60C wlll be reached. Then the decomposition of the organic substances by thermophile microorganisms, e.g. actinomycetes, is carried out which turned out to be advantageous. Typically the temperature in the container or in the rotting material lies between 60C and 80C. Said range of temperature is to be --maintained.
According to another advantageous further development the water contained in the used air is separated by cooling and condensation, preferably in a heat exchanger. The exhaust air -leaving the container may e.g. have a temperature of for --instance 45 to 80 when it reaches the heat exchanger. The exhaust air is cooled e.g. in a heat exchanger, in order to remove the water contained therein and produced in the container during the rotting process by condensation. The - : -exhaust air freed from the water contained therein in such a -~
manner is then once again fed to the container. Then it may have a temperature of for instance 20C. It is possible to -~
influence the extent of the cooling of the exhaust air, for instance by a respective control of the heat exchanger.
Thereby the temperature in the container (reactor) can be ~-influenced. When the exhaust air will only be cooled to a -minor extent in the heat exchanger, it is returned to the container with a higher temperature, whereby the temperature ~ -in the container and in the rotting material increases, or decreases to a minor extent. On the other hand, when the ;~
:~ ,::-.:
,.. , ,, . , , ,, . .. : ~ : ~ ,.
2127~3 g exhaust air is cooled to a greater extent, lt is returned to the container with a lower temperature, whereby the temperature in the container or in the rotting material is lowered, or increased to a minor extent.
Instead thereof or additionally thereto, the temperature in the container or in the rotting material may he influenced or controlled by the amount of gas circulated per unit time. When the amount of gas circulated pex unit time is increased, a larger cooling takes place in the rotting material. When, viceversa, the amount of gas circulated per unit time is -reduced, there is an increase in temperature in the rotting material.
When the rotting material still to be rotted (substrate) runs low after a predetermined time of for instance approximately seven days, i.e. when only a relatively small amount of rotting mat~rial to be composted is present, the amount of heat produced in the rotting material per unit time will decrease. This leads to the fact that also the temperature of -the rotting material is lowered. In order to be able to maintain the preferred temperature of at least 60C or of 60C
to 80~C, the above explained measures may b~ carried out individually or in common. Thus it is possible to cool the exhaust air to a minor extent and/or to lower the amount of gas circulated per unit time.
The point of time at wh$ch the substrate to be composted becomes less in the described manner is that point of time at which the organic parts of the waste material which are easier to be decomposed biologically have been decomposed in the sense of the German patent specification 36 37 393.
According to a further advantageous development energy, preferably electric energy is generated from the heat contained in the exhaust air. Here preferably the heat released during the condensation of the water contained ln the exhaust air is used. Said heat may preferably be conveyed via a heat exchanger to another medium which in turn may drive an engine. Said engine can produce electrical current. By the method according to the invention it is possible for the first time to produce such an amount of heat during the biological composting that said heat may then also be used for the production of mechanical energy. ~ecisive therefor is not only the produced amount of heat but also the temperature profile, i.e. the available difference in temperature. When the rotting material has a temperature between 60C and 80C, and when -~ -there is an ambient temperature of 20C, then there is available a temperature drop of 40C to 60C. The obtainable electric energy is sufficient to drive the blowers reguired for the air circulation. The energy produced in surplus ~ -thereof may be used for other purposes. Preferably said surplus electric energy may be used for the production of oxygen from the air. Preferably, said oxygen is supplied to -;~
the rotting material as pure oxygen.
A further advantageous development is characterized in that the amount of oxygen supplied per unit time is increased when the C2 content in the exhaust air or in the circulating air -~
or in the circulated gases increases. As already explained, ~-the C02 content in the exhaust air or in the circulating air raises in course of time, since no C2 is removed. For the compensation of said increasing C02 content the amount of supplied oxygen is raised. Preferably this is carried out proportional to the accumulation of the C02 content in the circulated gas. Consequently, the amount of oxygen supplied --- 2~27393 per unit time is preferably increased to the same extent as the C02 content in the circulated gas increases.
, According to the reaction equation C6H1206 + 602 a 6C02 + 6H20 + 674 kcal, half of the added oxygen is used for the production of water and the other half for the productlon of C02. The water can be separated, but it is not necessary. The formed C2 accumulates in the circulated gas. Thereby, i.e. by the increase of the mass in the closed system, also the pressure in the closed system is increased. Correspondingly, the output of the fans producing the circulating air guidance ~-may be increased in order to keep constant the amount of gas -circulated per unit time. But this is only true when the closed system is sufficiently tight. It is possible that minor leakages are present which prevent a pressure increase in the closed system, so that the fan output may remain identical.
By the invention the effectivity of the method is enormously increased. Said increase in effectivity is due to the fact that the biological energy release process which up to now has taken up a relatively large time, may now be carried out in a substantially shorter time period (which only amounts up to 1/4 to 1/3 of the time period required up to now). Thereby the output (composting output), i.e. the amount composted per unlt time is substantially increased. Furthermore also the usable energy release per unit time which can be used in the above described manner for the production of energy, i.e. the power (usable energy per time) is substantially larger and therefor economically interesting. -A further advantageous embodiment is characterized in that the exhaust gas is not filtered. Thereby the hitherto necessary expenditure involved therewith is avoided. It is possible to do without the exhaust air filtering, since the exhaust alr ls continuously and completely guided in the circuit, i.e.
circulated so that there is no exhaust air leaving the system which would have to be filtered. ~-, It is advantageous that the exhaust air is passed through a water bath which can be the condensate. Furthermore, the heat dissipated from the exhaust gas to the water bath may be preferably used by e.g. conveying said heat to a heat ~-exchanger. ~y the fact that the exhaust air is passed through -a water bath, the water present in the exhaust air may be -, .
removed from the exhaust air in a particularly simple and effective manner. By said process the exhaust air is cooled ;
and the water is condensed. The arrangements may me made such that the water bath is always given in the same amount. The water bath may for instance be realized as a water tank which --always has the same level. This can be easily realized ln that ~-in the tank there is provided an overflow and that the - --overflowing water is discharged.
The heat received by the water bath or the water tank may be dissipated, for instance via a circulation conduit with heat exchanger and/or cooling unit.
According to another advantageous development the exhaust ga is purified before the termination of the rotting process.
After the termination of the rotting process the closed container is opened, and the rotting material located therein and being at least in part composted, is removed from said container. Directly prior thereto the exhaust air or the air content of the closed container can be purified, in order to prevent an evading of the exhaust air into the atmosphere. In the course of said purification, in particular C2 may be : ~
removed from the air in order to avoid that after the opening of the closed container it escapes into the environment. The removal of CO2 may be carried out in a water bath with calcium oxide (CaO) or calcium hydroxide (CaOH). In the course of the purification there can also be removed ammonium, for instance ~-in a water bath with calcium hydrocarbonate or calcium hydrogen phosphate. The removal of ammonlum cannot only be carried out directly before the termination of the rotting process but also during the entire rotting process.
An apparatus for carrying out the method according to the invention consists of a closed container with an air supply means and an air discharge means through which the exhaust air can be once again supplied to the container. Furthermore there is provided an automatic aeration device which supplies the exhaust gas once again to the closed container. There may also be provided an oxygen supply means for supplying oxygen or pure oxygen, as well as a water discharge means for discharging the water removed from the exhaust air.
For the solution of the above-indicated ob~ect such an apparatus is characterized according to the invention in that no exhaust air filter is provided. As the exhaust air is completely circulated, no exhaust air leaving the system is present so that also no exhaust air filter is required.
An advantageous further development of the apparatus according to the invention is characterized in that in the air dlscharge means a water bath is provided through which the exhaust air may be passed. To the water bath or the water tank there is preferably supplied the condensate, i.e. the water removed from the exhaust air. The water tank may be provided with an overflow so that always the same water level is maintained ~..' ~' therein and that the overflowing water can always be removed.
A further advantageous development is characterized by a heat exchanger for dissipating the heat conveyed by the exhaust air to the water bath.
During operation, practically there takes place no change of pressure in the system. The system is always supplied wlth pure oxygen, but water is also always removed therefrom so that the entire volume of the system remains substantially identical and the pressure is practically not changed.
Claims (17)
1. Method for composting organic substances (rotting material), in particular waste material, for instance household garbage or garbage similar to household garbage, in which the rotting material is fed into a closed container and is decomposed microbially by supplying oxygen thereto, the rotting material being furthermore supplied with a mixture of pure oxygen and used air, characterized in that the CO2 contained in the used air is once again supplied to the rotting material and that from the exhaust air (used air) escaping from the rotting material the water contained therein is removed.
2. Method according to claim 1, characterized in that the exhaust air escaping from the rotting material is completely refed to the rotting material.
3. Method according to claim 1 or 2, characterized in that the exhaust air escaping from the rotting material is continuously refed to the rotting material.
4. Method according to any one of the foregoing claims, characterized in that the amount of gas circulated per unit time is increased when the temperature in the rotting material increases.
5. Method according to any one of claims 1 through 3, characterized in that the amount of gas circulated per unit time is reduced, when the temperature in the rotting material decreases.
6. Method according to any one of the foregoing claims, characterized in that the moisture content in the circulated gas is kept constant at a certain predetermined value.
7. Method according to any one of the foregoing claims, characterized in that the temperature in the container is at least 60°C.
8. Method according to any one of the foregoing claims, characterized in that the water contained in the exhaust air is separated by cooling and condensation, preferably in a heat exchanger.
9. Method according to claim 8, characterized in that from the heat conveyed during condensation preferably electric energy is produced.
10. Method according to any one of the foregoing claims, characterized in that the amount of oxygen supplied per unit time is increased when the CO2 content raises.
11. Method according to any one of the foregoing claims, characterized in that the exhaust air is not filtered.
12. Method according to any one of the foregoing claims, characterized in that the exhaust air is passed through a water bath, preferably the condensate.
13. Method according to claim 12, characterized in that the heat dissipated from the exhaust air to the water bath is conveyed to a heat exchanger.
14. Method according to any one of the foregoing claims, characterized in that the exhaust air is purified prior to the termination of the rotting process.
15. Apparatus for carrying out the method according to any one of the foregoing claims, consisting of a closed container with an air supply means and an air discharge means through which the exhaust air is once again supplied to the container, characterized in that no exhaust air filter is provided.
16. Apparatus according to claim 15, characterized in that in the air discharge means a water bath is provided through which the exhaust air may be passed.
17. Apparatus according to claim 16, characterized by a heat exchanger for dissipating the heat conveyed from the exhaust air to the water bath.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4322688.4 | 1993-07-07 | ||
| DE19934322688 DE4322688C2 (en) | 1993-07-07 | 1993-07-07 | Process for composting organic substances, especially waste |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2127393A1 true CA2127393A1 (en) | 1995-01-08 |
Family
ID=6492216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002127393A Abandoned CA2127393A1 (en) | 1993-07-07 | 1994-07-05 | Method and apparatus for composting organic substances, in particular waste material |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0633235B1 (en) |
| JP (1) | JPH07144988A (en) |
| AT (1) | ATE173240T1 (en) |
| CA (1) | CA2127393A1 (en) |
| DE (2) | DE4322688C2 (en) |
| DK (1) | DK0633235T3 (en) |
| ES (1) | ES2124817T3 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4406363A1 (en) * | 1994-02-26 | 1995-08-31 | Kessler & Luch Gmbh | Composting of bio-waste uses forced delivery of fresh air |
| DE19513262C1 (en) * | 1995-04-07 | 1996-10-24 | Herhof Umwelttechnik Gmbh | Process for composting organic matter, especially waste |
| DE19607308C1 (en) * | 1996-02-27 | 1997-06-05 | Messer Griesheim Gmbh | Rotting of waste in open or closed process, with introduction into waste of gas with higher oxygen concentration than air |
| ES2147504B1 (en) * | 1998-02-18 | 2001-04-01 | Kollvik S L | COMPOSITION SYSTEM OF ORGANIC WASTE. |
| DE10052918B4 (en) * | 2000-09-08 | 2008-12-04 | Herhof Verwaltungsgesellschaft Mbh | Seawater desalination process and apparatus using biogenic substances |
| WO2009034615A1 (en) * | 2007-09-11 | 2009-03-19 | Haruo Uehara | System for treating alcohol distillation residue |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| LU73974A1 (en) * | 1975-09-11 | 1976-07-01 | ||
| DE3637393A1 (en) * | 1986-02-19 | 1987-08-20 | Hermann Hofmann | Process and device for composting waste material |
| WO1988007507A1 (en) * | 1987-04-03 | 1988-10-06 | Hermann Hofmann | Process for composting organic material and device for carrying out this process |
| ES2066261T3 (en) * | 1990-05-09 | 1995-03-01 | Herhof Umwelttechnik Gmbh | PROCEDURE FOR THE COMPOSTATION OF WASTE. |
| DE4034400C2 (en) * | 1990-10-29 | 1994-05-26 | Grabbe Klaus | Method and device for composting microbially degradable waste materials |
| DE4107340C2 (en) * | 1991-03-07 | 1994-09-08 | Schnorr Karl Ernst | Process for composting organic waste |
-
1993
- 1993-07-07 DE DE19934322688 patent/DE4322688C2/en not_active Expired - Fee Related
-
1994
- 1994-06-27 AT AT94109916T patent/ATE173240T1/en not_active IP Right Cessation
- 1994-06-27 EP EP19940109916 patent/EP0633235B1/en not_active Expired - Lifetime
- 1994-06-27 DE DE59407260T patent/DE59407260D1/en not_active Expired - Fee Related
- 1994-06-27 ES ES94109916T patent/ES2124817T3/en not_active Expired - Lifetime
- 1994-06-27 DK DK94109916T patent/DK0633235T3/en active
- 1994-07-05 CA CA002127393A patent/CA2127393A1/en not_active Abandoned
- 1994-07-07 JP JP15608094A patent/JPH07144988A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ATE173240T1 (en) | 1998-11-15 |
| DE4322688A1 (en) | 1995-01-12 |
| DE4322688C2 (en) | 1995-07-27 |
| ES2124817T3 (en) | 1999-02-16 |
| DE59407260D1 (en) | 1998-12-17 |
| DK0633235T3 (en) | 1999-07-26 |
| JPH07144988A (en) | 1995-06-06 |
| EP0633235B1 (en) | 1998-11-11 |
| EP0633235A1 (en) | 1995-01-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7160456B2 (en) | Method and equipment for processing organic material | |
| CN105084966B (en) | A kind of film liner container-type installation for fermenting and utilize the device carry out compost, deodorization method | |
| US5591635A (en) | Methods and apparatuses for rapid composting with closed air loop circulation for positive control | |
| US5145581A (en) | Composting system utilizing air recirculation | |
| US6524848B2 (en) | Recirculating composting system | |
| JPH07124538A (en) | Solid organic waste-treating apparatus | |
| NO962349D0 (en) | Composting plant from organic waste and method of composting such waste | |
| KR101240539B1 (en) | Wastewater Treatment Plant capable of temperature controll of aeration tank | |
| CA2127393A1 (en) | Method and apparatus for composting organic substances, in particular waste material | |
| US5181950A (en) | Process for compositing organic waste and installation for implementing the process | |
| JP2010264447A (en) | Process for biological-thermal treatment of refuse | |
| CN215886850U (en) | Aerobic composting device | |
| JP3595748B2 (en) | Fermentation treatment apparatus and operation method thereof | |
| JP3913524B2 (en) | Compost manufacturing method | |
| EP0658153B1 (en) | Method of neutralizing and recovering of gases released from wet composting of domestic animal manure and/or sewage mud | |
| CZ4897A3 (en) | Waste water or sewage treatment process and apparatus for making the same | |
| AU729613B2 (en) | Bio-thermal treatment of refuse | |
| CN216005709U (en) | Closed compost fermentation device | |
| JP2007045706A (en) | Apparatus for producing compost | |
| JPH07241542A (en) | Method and apparatus for fermentation of organic material | |
| JPS5910956B2 (en) | Composting method for organic waste | |
| JPH10505054A (en) | How to compost organic matter, especially waste | |
| JP2000072583A (en) | Composting treatment of organic waste | |
| KR200372086Y1 (en) | High Speed Extinction Machine for Food Waste Equipped on the Vehicle | |
| KR0182838B1 (en) | An apparatus for fertilizer of livestock's night soil |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |