DE102005030980A1 - Gas yield improvement in plants for producing biogas from products resulting in agriculture, comprises fermenting the products, comminution/chopping of fragmented phase of the products and mixing the fragmented phase with continuous phase - Google Patents

Abstract

The gas yield improvement in biogas-plants (1) in which products are made available as bio-substrate (raw products) in the form of fragmented phase and a further component in the form of a continuous phase. The products are subjected to fermentation, and biogas, sediments and/or substrate are developed by the fermentation. The fragmented phase is comminuted or chopped to a size smaller than the existing dimension before mixing of the fragmented phase with continuous phase. The mixing of the products takes place spatially separated from the fermentation and in the space of the fermentation. The gas yield improvement in biogas-plants (1) in which products are made available as bio-substrate (raw products) in the form of fragmented phase and a further component in the form of a continuous phase. The products are subjected to fermentation and biogas, sediments and/or substrate are developed by the fermentation. The fragmented phase is comminuted or chopped to a size smaller than the existing dimension before mixing of the fragmented phase with continuous phase. The mixing of the products takes place spatially separated from the fermentation and in the space of the fermentation. The products are preheated before the fermentation and spatially separated from the fermentation. A part of the mixture taken from the fermentation space is circulated in a cycle and cooled. Corn containing the entire plant including the corn cob, complete plant silage in a very ripe pasty state, and grass silage are used as the bio-substrate. The bio-substrate is minced on a cut length of 1-3 mm. Liquid manure is intended as the continuous phase. An independent claim is included for an arrangement for gas yield improvement in plants for producing biogas from products resulting in agriculture.

Description

TECHNICAL AREA

The The invention relates to a method and an arrangement for improvement the gas yield in biogas production plants, in particular from agricultural products, in which they Products undergo a fermentation and through this fermentation at least biogas, sediments and / or substrate arises, and at to / the products to be fermented as a biosubstrate (Raw material) in the form of at least one lumpy phase and on the other as at least one further component in the form of a continuous one Be provided.

• • Belebtschlamm aus Kläranlagen;
• • Abfallprodukte der Tierhaltung wie Dung oder Gülle;
• • Pflanzenmaterial wie beispielsweise Stroh, Gras, Heu, Rüben, Mais und Ganzpflanzensilage (GPS) wie Grünroggen;
• • Rückstände der Nahrungsmittelproduktion wie Schlachthofabwässer, Brauereischlamm, Abwässer der Molkereien und Zuckerfabriken und Rückstände biotechnologischer Produktionsbetriebe und/oder
• • Hausmüll.

Biogas is about 50 to 60% methane, which is flammable and has a high calorific value, and carbon dioxide. It occurs in nature wherever organic matter is transformed by microorganisms in the absence of oxygen (anaerobic). Biogas can be obtained in biogas plants designed for this purpose, with the following starting materials being considered:

• • activated sludge from sewage treatment plants;
• • animal husbandry waste such as manure or manure;
• • Plant material such as straw, grass, hay, turnips, corn and whole plant silage (GPS) such as green rye;
• • residues of food production such as slaughterhouse effluents, brewery lamb, wastewater from dairies and sugar factories and residues of biotech production plants and / or
• • household waste.

Basics Problem with devices for the production of biogas is the mixing the initial material and seeded with suitable microorganisms, for example, manure. Desirable is one possible intensive mixing of manure, because it can increase the yield of biogas. Furthermore are the products to be fermented to fermentation temperature heat, as an insufficient temperature in the fermenter the fermentation process slow down and thereby reduce the yield of biogas. Similar Impact has an exceeding the optimal fermentation temperature, for example by overheating of the fermentation process.

By the DE 202 18 022 U1 already a device for the production of biogas of the generic type is known, which has set itself the goal of producing biogas in high yield, the device should also be easy to maintain and standardizable. With the known device, a method for producing biogas can be carried out, wherein a product to be fermented product is fed to a fermenter enclosed by a container via a feed and a filling agent arranged in the fermenter and the content of the fermenter is sprayed through at least one nozzle arranged at the bottom thereof , About the nozzle, a mixture comprising biogas and / or substrate is injected under a pressure in the fermenter. By the method, both a horizontal and a vertical mixing of the fermenter content is effected, whereby a higher yield of biogas takes place. By injecting a mixture of biogas and / or at least partially fermented substrate, which are preferably removed in the circulation process the fermenter content or the gas dome or the gas storage container, a horizontal and vertical mixing of the fermenter content is achieved in the injection.

Of the known device is preferably via the inlet a mixture from products to be fermented and from 20 to 75% by weight of beet silage, based on the total amount fed. It will be after the harvest the for the beet silage provided turnips vermust, einiliert and from the beet storage container, for example introduced into the fermenter by means of a metering pump. in this connection is in the pump or only downstream mixing the beet silage with the other products to be fermented, in particular manure, provided.

Of Another is the use of maize, comprising the entire plant including flask, or whole plant silage (GPS) or grass silage, this component being the component biosubstrate (raw material) forms within the products to be fermented. The respective Biosubstrate is usually in a shredder on a cut length in the range comminuted from 5 to 15 mm and forms the lumpy phase in this state within the products to be fermented.

The aforementioned prior art discloses that the previous efforts to increase the Gas yield in biogas production plants should be concentrated on measures within the fermenter and that the potential for development in this regard seems to have been exhausted to the greatest possible extent.

outgoing from the vorg. It is an object of the present invention to provide in a method and an arrangement of the generic type to further increase the yield of biogas.

SUMMARY OF THE INVENTION

Of the fundamental inventive thought is the attention in the effort to increase the yield of biogas, now on the pretreatment the lumpy Phase of the products to be fermented, the biosubstrate (the raw material), to judge and this lumpy Phase over that by hewing and / or Crushing exceeding previous level to crush and then to mix with the continuous phase. Through this new quality of crushing becomes the specific surface of the reaction partner chunky Phase increased, whereby a significant intensification of the mass transfer in the Framework of the fermentation process and thus an improvement in the Gas yield can be achieved in this process.

A preferred embodiment of the method according to the invention provides that mixing the products to be fermented, consisting of the lumpy Phase and the continuous phase, spatially separated from the fermentation he follows. In this case, a method is realized in which the products to be fermented are quasi "liquid" fed to the fermentation process. This method of so-called "liquid introduction" is preferred Application for the construction of new biogas plants.

The vorg. Method of liquid introduction is about it In addition, as recommended by another proposal, the mixture from the products to be fermented before and spatially separated from their fermentation a warm-up outside to undergo the fermenter. By the relevant preheating of the fermented Avoid products to the necessary fermentation temperature the otherwise usually to be accepted temperature fluctuations within the fermenter and the associated slowdown the fermentation process and reduce the yield of biogas.

existing Installations for the production of biogas in which the lumpy phase, the biosubrate (raw material), the fermenter is fed directly (so-called "solids introduction"), can from the comminution according to the invention also benefit if, as this is another embodiment of the proposed method according to the invention, the Mixing the products to be fermented, consisting of the lumpy phase and the continuous phase, takes place in the fermentation room. Now, the invention is comminuted lumpy Phase on the usual Path fed to the fermentation process, so in this area no change or adaptation of existing facilities is necessary.

A further advantageous embodiment of the method according to the invention provides that taken from the fermentation room part of the mixture of the products to be fermented, circulated in the circulation while spatially separated from the fermentation experiences a cooling. This process variant, in contrast to methods of "internal" and "external" heating according to the prior art, particularly well suited to protect, for example, the products to be fermented in the fermenter from overheating. Such "external" cooling of the products to be fermented is indicated, for example, when in the summer for several weeks outside temperature θ _a > 25 ° C prevails, so in the fermenter without cooling an optimal fermentation temperature of about θ _F = 37 ° C does not comply Well water is preferably used as the heat transfer medium (cooling medium) and overheating of the fermenter has comparable effects on the fermentation process, such as insufficient heating of the products to be fermented.

The inventive method is in a particularly advantageous manner, as provided, both in the process variant "liquid introduction" and in the process variant "solids introduction", for example using corn, comprising the entire plant including the piston, or whole plant silage (GPS) or grass silage feasible. In this regard, it is proposed to chop the respective lumpy biosubstrate (raw material) to a cutting length in the range of 1 to 3 mm. As a continuous phase of the products to be fermented, liquid manure is advantageously used in both process variants ("liquid introduction", "solid introduction"). It has been shown in this context that the gas yield when using the comminuted raw material (corn) according to the invention over the previously used, comminuted raw material by 10 to 12% (Δ = 0.1 - (0.12)) higher fails.

The Arrangement for implementation the method according to the invention is characterized in that between the staging container for the the usual Measure crushed lumpy Phase (biosubstrate / raw material) and the fermenter arranged a crusher is.

to Realization of the liquid introduction is further proposed that the crusher downstream of a mixing container is the latter, a terminal for supplying the continuous Phase has. By this arrangement, the provision of a pumpable Mixture achieved. In this connection, sees another advantageous embodiment the arrangement according to the invention before that to the mixing container a shell and tube heat exchanger over a Inlet line and an outlet line is connected via the in the mixing container contained mixture of the products to be fermented in the circulation circulated and preheated becomes.

existing Biogas plants with the so-called. Solid introduction are on the arrangement of the invention convertible, if, as a further proposal provides, between the comminuted invention and the fermenter a conveyor is arranged. In this case, the chopped lumpy phase according to the invention without significant change the feed to the fermenter supplied to this and there with the continuous Phase mixed.

The inventive arrangement is in a particularly advantageous manner, as is also intended, both in their embodiment with "liquid introduction" as well as in their Design with "solids introduction" for use of maize, comprising the entire plant including the Flask, or whole plant silage (GPS) or grass silage. In this regard, it is proposed that the respective lumpy biosubstrate (raw material) on a cut length to shred in the range of 1 to 3 mm. As a continuous phase of to be fermented products comes in both vorg. refinements the arrangement advantageously manure for use.

A further advantageous embodiment the arrangement according to the invention provides that a shell-and-tube heat exchanger connected to the fermenter such is that from the fermenter part of the mixture from the fermented Taken from products, circulated in the circuit via the tube bundle heat exchanger and while warmed up in this becomes. This solution is suitable to use existing plants for the production of biogas the advantages of an "external" heating to fermenting products by means of a suitable tube bundle heat exchanger equip.

According to another advantageous embodiment of the arrangement according to the invention, a shell-and-tube heat exchanger is connected to the fermenter such that withdrawn from the fermenter, a part of the mixture of products to be fermented, circulated in the circulation through the tube bundle heat exchanger and thereby cooled in this , This embodiment, in contrast to "internal" and "external" heating devices according to the prior art, is particularly well suited, for example, to protect the products to be fermented in the fermenter from overheating. Such "external" cooling of the products to be fermented is indicated, for example, when in the summer for several weeks outside temperature θ _a > 25 ° C prevails, so in the fermenter without cooling an optimal fermentation temperature of about θ _F = 37 ° C does not comply Well water is preferably used as the heat transfer medium (cooling medium) and overheating of the fermenter has the above-mentioned effects on the fermentation process.

BRIEF DESCRIPTION OF THE DRAWINGS

One respective embodiment a first and a second plant for the production of biogas according to the invention are shown in the drawing and are described below. Show it

1 a schematic representation of a first plant for the production of biogas according to the invention with so-called. "Liquid introduction";

1a in perspective, the system according to 1 ;

2 a schematic representation of a second plant for the production of biogas according to the inventions with so-called "solids introduction" and

2a in perspective, the system according to 2 ,

DETAILED DESCRIPTION

A first biogas plant 1 ( 1 and 1a ), in which a so-called "liquid introduction" of the products P to be fermented into a fermenter 2 is realized, is simplified, limited to essential components and seen in the direction of the material flow, from a staging container 3 , one of a drive motor 5 driven shredder according to the invention 4 , a mixing container 6 , a tube bundle heat exchanger connected in parallel to the latter 7 and the fermenter 2 , The above-described arrangement of the first biogas plant 1 is chosen when new plants for the production of biogas are equipped with the features according to the invention.

In the delivery container 3 a lump phase A of the products P to be fermented is provided. The exemplary embodiment should be the biosubstrate (raw material) maize comprising the entire plant, including the flask, the maize being harvested with a conventional corn harvester and comminuted to a cut length in the range of 5 to 15 mm. As biosubstrate A, it is also advantageous to use whole plant silage (GPS) or grass silage. The deployment container 3 has a volume that can accommodate half the daily amount of raw material, so it must be filled every 12 hours. The lumpy phase A is via a discharge line 3a and possibly in conjunction with a screw conveyor at the bottom of the staging container 3 removed and the crusher according to the invention 4 fed. In the latter, the lumpy phase A, the chopped corn or vorg. other lumpy biosubstrates A, comminuted to a cut length in the range of 1 to 3 mm.

The lumpy biosubstrate A (raw material, lumped phase A) comminuted in this way has, for example, in corn a dry subassembly of about 30% (DM 30%) and is produced by the comminutor 4 via a transfer line 4a the mixing container 6 fed. The latter preferably has a volume, which is a 12 to 18 "feeding" of the downstream fermenter 2 over a period of 24 hours. The mixing container 6 has a first connection 6a for supplying a continuous phase G, preferably manure, wherein the mixing container 6 among other things, the task for a sufficient mixing of the fermented products P to so-called, before these in the fermenter 2 be transferred.

The mixing container 6 downstream shell-and-tube heat exchangers 7 is at this over an entrance line 7a and an exit line 7b connected, which in the mixing tank 6 befindliches mixture of the products to be fermented P, for example, from the invention comminuted corn A and the manure G, a circulation U undergoes circulation and thereby to the required fermentation temperature in the fermenter 2 is preheated. The used tube bundle heat exchanger 7 must have the particular ability to be blocked by the lumpy phase A, which may possibly agglomerate to relatively long fibrous components, not to be clogged.

The feeding of the mixture of products P (A + G) to be fermented into the fermenter 2 via a feed of the first kind 2a , In the fermenter 2 produced by the fermentation process from the products P to be fermented, the lumpy biosubstrate A and the manure G, the biogas B (methane and carbon dioxide) as well as sediments and / or substrate S.

A second biogas plant 10 ( 2 and 2a ), in which a so-called. "solid introduction" of the fermented products P in the fermenter 2 is realized, is simplified, limited to essential components and seen in the direction of the material flow, from the staging container 3 , that of the drive motor 5 driven shredder according to the invention 4 and a conveyor 8th , the suction side via the transfer line 4a with the crusher 4 is connected and the pressure side via an inlet of the second kind 2 B for feeding the lumpy phase A to be fermented, in the present case of the biosubstrate maize, into the fermenter 2 opens. The continuous phase G, in this case the slurry G, passes through a second port 2c in the fermenter 2 , The above-described arrangement of the second biogas plant 10 exists if existing plants for the production of biogas with the shredder according to the invention 4 be retrofitted.

In the 1 . 1a is not shown as a shell-and-tube heat exchanger 7 with the fermenter 2 must be piped to a warming in the fermenter 2 submitted to be fermented products P to to reach. In this case is to the fermenter 2 the tube bundle heat exchanger 7 connect so that from the fermenter 2 a part of the mixture of the products P to be fermented taken, in the circulation through the shell-and-tube heat exchanger 7 circulated and thereby can be heated in this.

In addition, the show 2 . 2a not like a shell-and-tube heat exchanger 7 with the fermenter 2 must be piped to a cooling of the fermenter 2 reached to be fermented products to reach P. In this case is to the fermenter 2 the tube bundle heat exchanger 7 connect so that from the fermenter 2 a part of the mixture of the products P to be fermented taken, in the circulation through the shell-and-tube heat exchanger 7 circulated while being cooled in this. As a heat transfer medium (cooling medium) here preferably well water is used.

The Improvement of gas yield in biogas production plants by the inventively proposed activities is significant and obvious, with this improvement both in the method and arrangement with "liquid introduction" as well as those with "solid introduction" occurs.

The fact that the measures according to the invention are also cost-effective is shown below by way of example and roughly on a biogas plant with an electric power of P _electr = 500 kW fed into the power grid. Data CALCULATION EXAMPLE • Electricity fed into the mains. Power: P _electr = 500 kW • Energy conversion efficiency biogas → electrical energy: η = 0.9 Daily throughput (lump phase A): Q = 20 t corn / d Energy expenditure for the comminution of the lumpy phase A to a cutting length in the range of about 1 to 3 mm: W _Z = 9 - 10 kWh / t maize Increase of the gas yield by the comminution according to the invention (10 - (12)%): Δ = 0.1 - (0.12) • Feed-in tariff: p = 0.16 EUR / kWh

The additional annual profit g in EUR / a without the wear and tear costs of the shredder according to the invention is calculated using the vorg. Data approximate from the following formula (1): g = [p Electric 24 (h / d) η Δ - QW Z ] 365 (d / a) p (1).

In this mean: P Electric 24 (h / d) η Δ = 500 kW 24 h / d 0.9 0.1 = 1080 kWh / d (1a) the additional daily energy yield of the plant and Q × W Z = 20 t / d × 10 kWh / t = 200 kWh / d (1b) the daily energy expenditure for the comminution according to the invention.

This is g = [1,080 kW h / d - 200 kWh / d] 365 d / a 0,16 EU R / kW hg = 880 kWh / d 365 d / a 0,16 EUR g = 51,392 EUR / a , (1)

1

erste Biogas-Anlage

2

Fermenter

2a

Zulauf erster Art

3

Bereitstellungsbehälter

3a

Auslaufleitung/Förderschnecke

4

Zerkleinerer

4a

Überführungsleitung

5

Antriebsmotor

6

Anmischbehälter

6a

erster Anschluss

7

Rohrbündel-Wärmeaustauscher

7a

Eintrittsleitung

7b

Austrittsleitung

A

stückige Phase (Biosubstrat/Rohware; z.B. Mais, GPS, Grassilage)

B

Biogas

G

kontinuierliche Phase (Gülle)

P

zu fermentierende Produkte (A + G)

S

Sedimente und/oder Substrat

U

Umwälzung

1 . 1a

1

first biogas plant

2

fermenter

2a

Feed of the first kind

3

Deployment container

3a

Outlet pipe / auger

4

shredder

4a

Transfer line

5

drive motor

6

mixing tank

6a

first connection

7

Shell and tube heat exchangers

7a

inlet line

7b

exit line

A

lumpy phase (biosubstrate / raw material, eg corn, GPS, grass silage)

B

biogas

G

continuous phase (liquid manure)

P

fermented products (A + G)

S

Sediments and / or substrate

U

circulation

10

zweite Biogas-Anlage

2b

Zulauf zweiter Art

2c

zweiter Anschluss

8

Fördereinrichtung (z.B. rotierende Verdrängerpumpe)

2 . 2a as 1 . 1a without 1 . 2a . 6 . 6a . 7 . 7a . 7b ; In addition:

10

second biogas plant

2 B

Inlet of the second kind

2c

second connection

8th

Conveyor (eg rotary positive displacement pump)

Claims (21)

Process for improving the gas yield in plants producing biogas, in particular from agricultural products, in which these products are subjected to fermentation and at least biogas, sediments and / or substrate are produced by this fermentation, and in which the products to be fermented ( P) are provided on the one hand as a biosubstrate (raw material) (A) in the form of at least one lumpy phase and on the other as at least one further component in the form of a continuous phase (G), characterized in that the lumpy phase (A) via the Crushing and / or crushing previous measure comminuted and then mixed with the continuous phase (G). Method according to claim 1, characterized in that that mixing the products to be fermented (P), consisting from the lumpy Phase (A) and the continuous phase (G), spatially separated from the fermentation he follows. Method according to claim 2, characterized in that that the mixture of products to be fermented (P) before and spatial undergoes preheating separately from its fermentation. Method according to claim 1, characterized in that that mixing the products to be fermented (P), consisting from the lumpy Phase (A) and the continuous phase (G), in the fermentation room he follows. Method according to one of claims 1 to 4, characterized that from the fermentation room part of the mixture of the taken to be fermented products (P), circulated in the circulation and while spatially is cooled separately from the fermentation. Method according to one of claims 1 to 5, characterized that as a biosubstrate (A) maize comprising the entire plant including the Piston, is used. Method according to one of claims 1 to 5, characterized that as biosubstrate (A) whole plant silage (GPS), in the state of Dough maturity, is used. Method according to one of claims 1 to 5, characterized that grass silage is used as the biosubstrate (A). Method according to one of claims 6 to 8, characterized that the biosubstrate A (corn, GPS, grass silage) to a cut length in the range crushed from 1 to 3 mm. Method according to one of claims 1 to 9, characterized that as a continuous phase (G) manure is provided. Arrangement for improving the gas yield in plants for producing biogas, in particular from agricultural products, with a biogas plant ( 1 ; 10 ), consisting of a fermenter ( 2 ), with a feed ( 2a ; 2 B ) for the supply of products to be fermented (P), wherein at least biogas, sediments and / or substrate is formed by the fermentation and the products to be fermented (P) as a biosubstrate (raw material) (A) in the form of at least one lumpy phase and the other than at least one further component in the form of a continuous phase (G) in delivery containers ( 3 ), characterized in that between the supply container ( 3 ) for the lumpy phase (A) and the fermenter ( 2 ) a crusher ( 4 ) is arranged. Arrangement according to claim 11, characterized in that the crusher ( 4 ) a mixing container ( 6 ), the latter still having a connection ( 6a ) for supplying the continuous phase (G). Arrangement according to claim 12, characterized in that the mixing container ( 6 ) a shell-and-tube heat exchanger ( 7 ) via an entry line ( 7a ) and an outlet line ( 7b ) is connected via the in the mixing container ( 6 ) is circulated in the circulation of the products to be fermented (P; A, G) and preheated. Arrangement according to claim 11, characterized in that between the crusher ( 4 ) and the fermenter ( 2 ) a conveyor ( 8th ) is arranged. Arrangement according to one of claims 11 to 14, characterized that as a biosubstrate (A) maize comprising the entire plant including the Piston, is used. Arrangement according to one of claims 11 to 14, characterized that as biosubstrate (A) whole plant silage (GPS), in the state of Dough maturity, is used. Arrangement according to one of claims 11 to 14, that as a biosubstrate (A) Grass silage is used. Arrangement according to one of Claims 15 to 17, characterized that the biosubstrate (A) (corn, GPS, grass silage) to a cut length in the range crushed from 1 to 3 mm. Arrangement according to one of claims 11 to 18, characterized that as a continuous phase (G) manure is provided. Arrangement according to one of claims 11 to 19, characterized in that the fermenter ( 2 ) a shell-and-tube heat exchanger ( 7 ) is connected in such a way that from the fermenter ( 2 ) a part of the mixture of the products to be fermented (P) taken in the circulation through the shell-and-tube heat exchanger ( 7 ) is circulated while being heated in this. Arrangement according to one of claims 11 to 19, characterized in that the fermenter ( 2 ) a shell-and-tube heat exchanger ( 7 ) is connected in such a way that from the fermenter ( 2 ) a part of the mixture of the products to be fermented (P) taken in the circulation through the shell-and-tube heat exchanger ( 7 ) is circulated and thereby cooled in this.