DE102005048116A1 - Method and device for producing fertilizer shaped bodies from fermentation residues obtained by energy generation by means of fermentation in a biogas plant - Google Patents

Abstract

The method according to the invention for the production of shaped fertilizer bodies from fermentation residues obtained by energy generation by fermentation in a biogas plant comprises the following steps: DOLLAR A a) providing a fermentation residue with a first nutrient content; DOLLAR A b) separation of the digestate into a solid part and a liquid part; DOLLAR A c) drying the solids content; DOLLAR A d) increasing the nutrient content of the solids content; and DOLLAR A e) reshaping the solids content into fertilizer tablets. DOLLAR A The method according to the invention and the device according to the invention advantageously allow the fermentation residues in biogas plants to be used as sustainably as possible. The shaped fertilizer body produced according to the invention advantageously releases the nutrients contained more slowly than correspondingly unprocessed fermentation residues, so that the over-fertilization of fields and the occurrence of nutrients, in particular nitrites, nitrates and phosphates in the groundwater, are advantageously reduced. In particular, the waste heat from a heat engine operated with the generated biogas can advantageously be used to dry the solids content and for heating during the further processing of the fermentation residues. An advantageous further development is directed towards the purification of the resulting waste water by means of evaporation and a subsequent reverse osmosis.

Description

object The present invention is a method and an apparatus for the production of fertilizer shaped bodies by energy production by means of fermentation in a biogas plant obtained fermentation residues.

at the recovery of agricultural waste is applied during application the excrements of farm animals in the form of manure on agricultural used areas the nutrients contained in the excretions are used for fertilization. Manure is also used as fuel for biogas plants, in which a fermentation to form methane containing Biogas and a subsequent Use of this biogas is done in a heat engine. at fermentation residues form during fermentation, which can not be further fermented and disposed of have to. Also these fermentation residues are used partly as fertilizer Applied to agricultural land.

So applied fertilizer have a low dry matter content and are in particular also liquid. This fertilizer be in case of rainfall washed out quickly and are then no more than nutrients for on the agricultural land planted plants available. In addition, these fertilizers a source of nitrite and / or nitrate pollution from waters and Groundwater, because due to the liquid form of the fertilizer much more nutrients be released as just recorded by the respective plants can be. Furthermore, it is due to the very low nutrient concentration with a large amount of liquid required, big Quantities of manure or digestate for one to apply proper fertilization. This is necessitated by the manure or digestate load the use of heavily loaded agricultural machinery, which is an undesirable oversized compaction effect of the soil. This unnecessary additional Compaction of the soil impedes the penetration of nutrients in the manure or the digestate in the soil and worsens the ventilation of the soil.

Generally It is an object of the present invention, the above and to alleviate disadvantages arising from the prior art or even to overcome.

Farther The present invention is based on the object, a method and to propose a device for the treatment of fermentation residues from biogas plants, the improved utilization of the nutrients contained in the fermentation residues allows.

moreover there is an object of the invention in it, an ecological one and thus a more sustainable process for the utilization of digestate provide. This applies in particular with regard to the improved Dosage of nutrients and a gentler application of the digestate to the ground.

These Tasks are solved by a method and a device having the features of the respective ones independent Claims. The respective dependent claims are directed to advantageous developments.

• a) Bereitstellen eines Gärrestes mit einem ersten Nährstoffgehalt;
• b) Trennen des Gärrestes in einen Feststoffanteil und einen Flüssiganteil;
• c) Trocknen des Feststoffanteils;
• d) Erhöhen des Nährstoffgehaltes des Feststoffanteils; und
• e) Umformen des Feststoffanteils in Düngemittelformkörper.

The process according to the invention for producing fertilizer shaped bodies from fermentation residues obtained by energy generation by means of fermentation in a biogas plant comprises the following steps:

• a) providing a digestate with a first nutrient content;
• b) separating the digestate into a solids fraction and a liquid fraction;
• c) drying the solids content;
• d) increasing the nutrient content of the solids content; and
• e) reshaping of the solids content in fertilizer shaped bodies.

biogas includes, for example, methane, hydrogen, carbon dioxide and hydrogen sulfide. It occurs during anaerobic (oxygen-free) fermentation of organic material. As starting materials for technical production of biogas are fermentable, biomass-containing residues such as sewage sludge, organic waste, Leftovers and manure. The term biogas plant is understood to mean a plant in which biodegradable material such as, in particular, manure, plants, Cereals and the like fermented by bacteria anaerobically and biogas is obtained. The resulting Biogas is used, for example, for the operation of heat engines, especially in combined heat and power plants.

The sequence of steps a) to e) according to the invention results in an increase in the dry matter content of the fertilizer. Under a dry matter content is the anhydrous content of solid and dissolved organic and inorganic substances. By fermentation is meant in particular the chemical conversion of substances, in particular by bacteria and enzymes, for example in the form of fermentation. The digestate is the residue of biogas production. A nutrient content is understood here in particular as a so-called NPK value, which indicates the proportions of nitrogen (N), phosphorus (P) and potassium (K) in the fertilizer. This is understood to mean, in particular, the proportions of corresponding compounds derived from a plant can be absorbed and implemented. Step b) is understood in particular to mean a separation in which the liquid fraction comprises a dry matter content of less than 5% by weight (% by weight). In step d), the nutrient content is further increased, for example by adding other fertilizers, for example mineral fertilizers. In particular, in step d) the nitrogen, the phosphorus and / or the potassium content can be increased, so that here fertilizer shaped bodies can be produced which meet certain specifiable requirements, for example, are particularly suitable for a particular plant variety. In addition to an increase in the nitrogen, phosphorus and / or potassium content, it is also possible, in particular, to add other nutrient concentrates, for example iron or the like. In this way, the inventive method allows a fertilizer "on demand", so adapted to the wishes and needs of customers.

The Provision has as a fertilizer molding across from a utilization of the digestate in the form of liquid fertilizer benefits, because of the fertilizer the nutrients present in him over a longer period as in liquid fertilizer. Such a fertilizer In particular, the principle of sustained release (sustained release) of the nutrients consequences. The timeframe in which nutrients can be given in particular to the type of fertilizing Plants are adapted so that over-fertilization and / or penetration of nutrients into the groundwater can be avoided. In particular, this can Adaptation in step d), in which a corresponding nutrient content is adjusted and / or added in the other additives which, for example, bind water and / or otherwise the delivery of nutrients inhibit and / or retard water. When Water-binding substances are, for example, alumina, silica gel and / or hydrophilic polymers can be used. Furthermore, for example, more Additives are added, in particular pesticides or similar, so as to the fertilizer moldings adapt to special events. Preferably takes place in step d) the addition of nutrients, an at least partial chemical conversion of in the solids content contained substances to nutrients and / or a further concentration of the solids content.

One Another advantage of fertilizer tablets in the Comparison for example with manure or too liquid digestate lies in a better way, the fertilizer to store. In the storage of fertilizer moldings, ie in the storage of granular media, there is no compelling in liquid fertilizers Need to use a tight tank for storage. moreover can by the method according to the invention the digestate storage capacities around to to 80% and the transport costs by up to 60% over the direct application of the digestate on agricultural land be reduced. It is also advantageous for a certain amount of nutrients the mass of the fertilizer to be transported on the agricultural acreages in the method according to the invention produced fertilizer moldings lower as in the application of liquid digestate or manure. As a result, the compaction of the soil by the application of the fertilizer reduced.

in the Comparison to the direct application of the digestate and / or manure on agricultural land In addition, a considerably lower odor nuisance occurs. Under fertilizer moldings is here any kind of fertilizer understood in solid, defined form, in particular pellets and Prills for the fertilization larger areas, in particular on agricultural land, in the utility and / or ornamental garden or in parks or even a fertilizer rod for use especially in potted plants.

Of the Dry substance content of the fertilizer shaped body is in a particularly advantageous manner after step e) at more than 80 Wt .-%. Particularly advantageous is a dry matter content of 85 wt .-% and more, since this is particularly advantageous for storage the fertilizer moldings exposed has, since just at this dry matter content, the molding in the storage remain dimensionally stable, the friction between adjacent bodies only to a small extent leads to abrasion and In addition, a baking of adjacent moldings is omitted, the moldings thus pourable stay.

Advantageous is a development of the method in which in step b) in Solid content reached a dry matter content of 20 wt .-% to 30 wt .-% becomes.

According to one advantageous embodiment of the method according to the invention comprises step b) a mechanical separation.

The execution a mechanical separation to separate a solid fraction and a liquid fraction has proven to be particularly advantageous because such a separation, for example, on a centrifugal force or the like based, is easy and durable to implement.

• – Dekantieren und
• – Separieren durch einen Schneckenseparator.

Particularly advantageous in this connection is an advantageous development of the method according to the invention, in which step b) comprises at least one of the following methods:

• - Decant and
• - Separate by a screw separator.

Schneckenseparatoren are sold for example by the company FAN Separator GmbH

Farther an embodiment of the method according to the invention is advantageous, wherein by step c) a dry matter content of 78 wt .-% to 82% by weight achieved becomes. Such a dry matter content allows in a particularly advantageous Way a simple increase the nutritional content by adding usual concentrated fertilizers, because with such dry matter shares a simple and effective Mix solid fertilizer possible with the solids content is. For example, you can static mixers are used.

According to one other possible Further development of the method according to the invention the fertilizer shaped bodies have one Dry matter content of at least 85%. Such fertilizer shaped bodies have a particularly good storage and transportability on.

Farther advantageous is a development of the method according to the invention, in which in step c) a temperature of 70 to 90 ° C is present. These Temperatures have proven to be particularly advantageous since these Temperatures in an advantageous manner by using the waste heat of the Heat engine in particular a cogeneration unit powered by biogas, can be achieved. Thus, an efficient use of the waste heat of the heat engine is possible.

• – einen Gewichtsanteil der Stickstoffverbindungen von 0,6 bis 0,8 Gew.-%,
• – einen Gewichtsanteil der Phosphorverbindungen von 0,6 bis 0,8 Gew.-% und
• – einen Gewichtsanteil der Kaliumverbindungen von 0,2 bis 0,3 Gew.-%.

Further preferred is a development of the process in which the solid fraction produced in step b) has at least one of the following substance fractions:

• A weight proportion of the nitrogen compounds of 0.6 to 0.8% by weight,
• A weight proportion of the phosphorus compounds of 0.6 to 0.8 wt .-% and
• - A weight proportion of potassium compounds of 0.2 to 0.3 wt .-%.

this includes In particular, the nitrogen, phosphorus and / or potassium compounds understood, which are absorbed by plants as nutrients can. In particular, these are ammonium nitrogen, nitrate nitrogen, Neutralammonicitratlösliches and water-soluble Phosphate, water-soluble Potassium oxide or chloride.

• – einen Gewichtsanteil der Stickstoffverbindungen von 2 bis 3,5 Gew.-%,
• – einen Gewichtsanteil der Phosphorverbindungen von 2 bis 3,5 Gew.-% und
• – einen Gewichtsanteil der Kaliumverbindungen von 0,5 bis 1,5 Gew.-%.

Also advantageous is a process procedure in which, after step c), the solids content has at least one of the following proportions of the substance:

• A weight proportion of the nitrogen compounds of 2 to 3.5% by weight,
• A weight proportion of the phosphorus compounds of 2 to 3.5% by weight and
• - A weight proportion of potassium compounds of 0.5 to 1.5 wt .-%.

According to one further advantageous embodiment of the method according to the invention in step d) the addition of nutrients takes place.

Under the term nutrients are understood here in particular nitrogen, phosphorus and / or potassium compounds, which can be absorbed, utilized and / or implemented by plants. Especially can the nutrients in the form of mineral fertilizers take place, which has a predeterminable proportion by weight of nitrogen, Have phosphorus and / or potassium compounds and represent a so-called NPK fertilizer. Especially Fertilizer can be added be, which has a high dry matter content, in particular a dry matter content of 95 wt .-% and more or even of 98 wt .-% and more. While or after the addition, a mixture of the solids content with the added nutrients or with the added fertilizer. Here in particular a compulsory mixer are used, which in particular comprises a stirrer. Also other mixing methods can used according to the invention become.

• – Stickstoff,
• – Phosphor und
• – Kalium.

Particularly preferred in this context is a process in which a mineral fertilizer is added which comprises at least one compound comprising at least one of the following substances:

• - Nitrogen,
• - Phosphorus and
• - Potassium.

Especially these are compounds derived from a plant nutrient can be recorded, recycled and / or implemented, preferably nitrites, nitrates, phosphates and / or potassium oxide.

Prefers is also a development of the method in which the solids content a release inhibitor is added. Under a release inhibitor is understood a substance that the release of nutrients, especially the Nitrogen, phosphorus and / or potassium compounds slows down. These are preferably water-binding substances such as, for example Alumina, silica gel, and / or hydrophilic polymers.

• – ein Gewichtsanteil von Stickstoffverbindungen von bis zu 25 Gew.-%,
• – ein Gewichtsanteil von Phosphorverbindungen von bis zu 20 Gew.-% und
• – ein Gewichtsanteil von Kaliumverbindungen von bis zu 30 Gew.-%.

According to a further advantageous embodiment of the method according to the invention, after step d) at least one of the following substance components is present:

• A weight proportion of nitrogen compounds of up to 25% by weight,
• A weight fraction of phosphorus compounds of up to 20% by weight and
• A weight proportion of potassium compounds of up to 30% by weight.

Especially these are the weight fractions of those nitrogen, Phosphorus and / or potassium compounds derived from a plant as nutrient recorded, exploited and / or implemented. The Weight fractions stated here have proven to be particularly advantageous proved, since with them a good long-term effect of the fertilizer is achieved while avoiding too fast release of the fertilizer becomes. Also, the so-called burning and / or over-fertilization of plants can be in an advantageous Way be avoided.

According to one further advantageous embodiment of the method according to the invention the solids content is pressed in step e). The squeeze of the Solids content represents a simple method of manufacturing Fertilizer shaped bodies, the production of fertilizer shaped bodies in big number in a short time. In addition, such press processes require for example a kind of pelleting relatively simple tools, which are easy to maintain and durable. Also a kind of extrudation the fertilizer molding is possible and according to the invention.

According to one further advantageous embodiment of the method according to the invention Fertilizer moldings become one length of 2 cm to 5 cm and a diameter of 0.3 cm to 0.6 cm formed.

These lengths and / or diameter have proven to be particularly advantageous here when fertilizing of agricultural land releasing the nutrients in the fertilizer shaped bodies relative is done slowly, so that the release is achieved the needs the one to be fertilized Plant can be adjusted and that the direct washout of the fertilizer is avoided. As a result, over-fertilization is avoided and in the Water cycle, especially those entering the groundwater and / or waters Amount of nutrients at least significantly reduced. Also preferred are lengths of 3 cm to 4 cm and diameter from 0.4 cm to 0.5 cm.

Advantageous is also a development of the method according to the invention, in which before Step e) is a thorough mixing of the solids content.

Especially then, if in step e) nutrients be added, is a thorough mixing of the solids content with the added nutrients advantageous. Preferably, the mixing takes place until a specifiable fluctuation range of the concentration of at least one nutrient preferably a proportion of nitrogen, phosphorus and / or potassium compounds, falls below a predefinable limit. This is especially at 5% by weight.

• – Stickstoff;
• – Phosphor und
• – Kalium

um mindestens einen vorgebbaren Faktor verkleinert worden ist.Preference is also given to a process procedure in which the mixing takes place until at least one width of a concentration distribution function of compounds of at least one of the following substances

• - nitrogen;
• - Phosphorus and
• - Potassium

has been reduced by at least one predeterminable factor.

Under a concentration distribution function is here in particular a Probability function understood the probability the occurrence of a certain concentration of one of the specified Substances and their compounds in a predeterminable volume element indicates. The better the mixing achieved, the narrower it is the achieved concentration distribution function. The specifiable In particular, factors range from 2 to 6, preferably from 3 to 5, in particular from about 4.

Especially preferred is a method in which the width is a full width at half height (FWHM) is.

Especially mixing takes place by means of a stirrer whose diameter 1.5 meters in a container corresponding diameter. It is preferred for 20 minutes at a rotation frequency mixed by 0.5 Hz.

According to the invention is in Step a) a digestate provided from a biogas plant.

• – Gülle,
• – Pflanzensilage,
• – Getreide und
• – Wasser.

According to a further advantageous embodiment of the method according to the invention, at least one of the following substances is fermented in the biogas plant to form a gas mixture:

• - Slurry,
• - plant silage,
• - cereals and
• - Water.

Under Manure will be Here, in particular excrement and / or urine of animals, preferably understood by farm animals. Under plant silage will in particular Plant material preserved by lactic acid fermentation Understood.

The manure is characterized in particular by a high cellulose content. As plant silage in particular grain silage, preferably corn silage or green leaf silage is used. In particular, wheat is understood to mean wheat, rye, oats, barley, with rye being particularly preferred.

The Plant silage offers a good biogas yield if possible low use, especially from a cost point of view. The Addition of grain is preferably discontinuous, since the fermentation of cereals very quickly. So can through the targeted addition from grain times of low ferocity ended become. The water content determines the consistency of the mixture to be fermented, in particular can so the Gäraktivität and the Rheology of the mixture can be adjusted. The manure stabilized the proportion, the growth and / or the activity of the fermentation Bacteria.

• – einen Gülleanteil von 15 Gew.-% bis 18 Gew.-%;
• – einen Pflanzensilageanteil von 58 Gew.-% bis 61 Gew.-%;
• – einen Getreideanteil von 4 Gew.-% bis 6 Gew.-% und
• – Wasser von 18 Gew.-% bis 21 Gew.-%.

It is preferred that in the biogas plant, a substance mixture is fermented, which includes the following proportions:

• - A slurry content of 15 wt .-% to 18 wt .-%;
• A plant silage content of from 58% to 61% by weight;
• - A cereal share of 4 wt .-% to 6 wt .-% and
• - Water from 18 wt .-% to 21 wt .-%.

According to one further advantageous embodiment of the method according to the invention the gas mixture produced comprises methane.

According to one further advantageous embodiment of the method according to the invention is in the biogas plant, a gas mixture is generated, which is a Heat engine fed.

Especially it can be with the heat engine an internal combustion engine, preferably a combined heat and power plant, preferably comprising a combined heat and power act. Furthermore, it is inventively possible, for example, as a heat engine to use a fuel cell.

• – Schritt c),
• – Beheizung mindestens eines Fermenterbehälters,
• – Aufheizung von Gülle und
• – einer Verdampfung des Flüssiganteils.

According to a further advantageous embodiment of the method according to the invention, at least part of the waste heat of the heat engine of the gas mixture is used for at least one of the following processes:

• Step c),
• Heating at least one fermenter tank,
• - Heating of manure and
• - Evaporation of the liquid fraction.

The Here described advantageous development of the method can advantageously also independently of the others described Procedural features and in particular independent of the steps a) to e) in the processing of digestate carried out by biogas plants become. Under a fermenter tank is here in particular a container understood, run in the fermentation in the biogas plant can. The heating of the manure in particular serves to sanitize the manure and preferably takes place until to a temperature of 70 ° C or more. Among the sanitation is in particular the reduction and / or elimination of pathogens and / or phytopathogens Understood. The use of waste heat described here Heat engine elevated advantageously the overall efficiency of the entire system and leads in particular to one as possible sustainable use of the starting materials used.

According to one further advantageous embodiment of the method according to the invention becomes the liquid fraction subjected to evaporation to produce a concentrate.

The Evaporation of the liquid fraction described here can be advantageous Way also independent from the other described method features and in particular independently from the steps a) to e) in the processing of the digestate of Biogas plants carried out become. In addition to a concentrate in which the nutrient content of the liquid fraction elevated is, creates a condensate, its nutritional content in comparison to the original one nutrient content of the liquid fraction is reduced.

Prefers is a development of the method in which a vacuum evaporation is carried out.

Especially a method is preferred in which the vacuum evaporation in a Temperature of 65 ° C up to 90 ° C carried out becomes.

Farther preferred is a method in which the vacuum evaporation in a Pressure of 5 Torr (about 667 Pascals) to 25 Torr (about 3333 Pas cal) is performed. Particularly preferred are a pressure of 16 Torr (about 2133 Pascal) and / or a pressure generated by a water jet pump.

• – einen Gewichtsanteil von Stickstoffverbindungen von 0,5 Gew.-% bis 1,5 Gew.-%;
• – einen Gewichtsanteil von Phosphorverbindungen von 0,05 bis 0,2 Gew.-% und
• – einen Gewichtsanteil von Kaliumverbindungen von 0,5 bis 1,5 Gew.-%.

A further development of the method is advantageous in which the concentrate has at least one of the following proportions of substance:

• A weight proportion of nitrogen compounds of from 0.5% to 1.5% by weight;
• A weight proportion of phosphorus compounds of 0.05 to 0.2 wt .-% and
• - A proportion by weight of potassium compounds of 0.5 to 1.5 wt .-%.

• – 80 bis 100 mg/l chemischer Sauerstoffbedarf (CSB),
• – 20 bis 40 mg/l Ammonium-Stickstoff (NH₄-N),
• – 5 bis 10 mg/l Phosphor und
• – 20 bis 50 mg/l Stickstoff.

Also preferred is a development of the process in which the condensate after evaporation has at least one of the following constituents:

• - 80 to 100 mg / l chemical oxygen demand (COD),
• 20 to 40 mg / l ammonium nitrogen (NH ₄ -N),
• - 5 to 10 mg / l phosphorus and
• - 20 to 50 mg / l nitrogen.

Under the amounts of phosphorus, nitrogen and ammonium nitrogen in particular comprising the appropriate amounts of compounds here understood these substances. Under the CSB is here in particular a Sum parameter understood that the amount of all organic compounds including in the water referred to the poorly degradable compounds. The COD value is particular understood to indicate the amount of oxygen which used for the oxidation of all organic matter contained in the water is using, for example, potassium dichromate as the oxidizing agent. The CSB is in particular in accordance with DIN 38 409-H41 understood.

According to one further advantageous embodiment of the method according to the invention A condensate is formed, which is at least partially a reverse osmosis is subjected.

The Condensate is formed preferably in the context of evaporation of the liquid fraction. The implementation a reverse osmosis in the condensate can advantageously also independently from the other described method features and in particular independently from the steps a) to e) in the processing of the digestate of Biogas plants carried out become. Preference is given to a process control in which the Condensate under high pressure on a semipermeable, in particular for water permeable Membrane is pressed. In particular, a membrane of the type Filmtec BW 30-400, sold here by imb + frings watersystems gmbh. Prefers the condensate of reverse osmosis is at a pressure of 20 bsi 25 bar subjected.

• – höchstens 90 mg/l chemischer Sauerstoffbedarf (CSB),
• – höchstens 20 mg/l biochemischer Sauerstoffbedarf nach 5 Tagen (BSB 5,),
• – höchstens 10 mg/l Ammonium-Stickstoff (NH₄-N),
• – höchstens 5 mg/l Phosphor und
• – höchstens 18 mg/l Stickstoff.

According to a further advantageous embodiment of the method according to the invention, the condensate has at least one of the following constituents

• - not more than 90 mg / l of chemical oxygen demand (COD),
• - maximum 20 mg / l biochemical oxygen demand after 5 days (BOD 5,),
• - not more than 10 mg / l of ammonium nitrogen (NH ₄ -N),
• - not more than 5 mg / l of phosphorus and
• - not more than 18 mg / l of nitrogen.

These Shares are especially after a reverse osmosis, preferably with reached the above parameters. Under the biochemical Oxygen demand after 5 days is especially the amount of oxygen understood which bacteria and other microorganisms in one Sample the condensate over a period of 5 days at a temperature from 20 ° C need, to aerobically break down the ingredients. Below the BOD 5 becomes a measure of the amount Oxygen understood that in a certain time for the biological Removal of organic wastewater ingredients is needed. Among the shares Of phosphorus, ammonium nitrogen and nitrogen in particular the corresponding proportion of compounds containing these substances Understood. These limits have proved to be harmless so that the condensate after the reverse osmosis Verregnungs- and / or Vorfluterfähig.

Especially advantageous is a procedure, in addition to the production of fertilizer tablets additionally the above described waste heat recovery and the treatment of the condensate by reverse osmosis used is, since here a good use of the introduced into the biogas plant Edukten existing energy at the same time as low as possible load the environment with undesirable Substances is achieved.

• A) Mittel zum Bereitstellen eines Gärrestes;
• B) Mittel zum Trennen des Gärrestes in einen Feststoffanteil und einen Flüssiganteil;
• C) Mittel zum Trocknen des Feststoffanteils;
• D) Mittel zum Erhöhen des Nährstoffgehaltes im Feststoffanteil; und
• E) Mittel zum Umformen in Düngemittelformkörper.

According to a further aspect of the present invention, an apparatus for producing fertilizer shaped bodies from fermentation residues obtained by energy generation by means of fermentation in a biogas plant is proposed, comprising

• A) means for providing a digestate;
• B) means for separating the digestate into a solids fraction and a liquid fraction;
• C) means for drying the solids content;
• D) means for increasing the nutrient content in the solids content; and
• E) Means for forming in fertilizer shaped body.

The inventive device is particularly suitable for carrying out the method according to the invention. The means A) preferably contain a biogas plant.

According to one advantageous embodiment of the device according to the invention include the agent B) mechanical release agent.

• – mindestens einen Dekanter und
• – mindestens einen Schneckenseparator.

According to a further advantageous embodiment of the device according to the invention, the means B) comprise at least one of the following devices:

• - at least one decanter and
• - at least one screw separator.

According to one further advantageous embodiment of the device according to the invention are means for producing a biogas and at least one heat engine designed to implement at least parts of the biogas.

Under a heat engine In particular, an internal combustion engine is preferred here a combined heat and power plant, preferably comprising a combined heat and power plant and / or a fuel cell understood.

According to one further advantageous embodiment of the device according to the invention For example, the means for producing a biogas include at least one Fermenter tank.

According to one further advantageous embodiment of the device according to the invention are evaporation means for evaporating the liquid fraction to form a Concentrate and a condensate formed. Preference is here a development in which the evaporation means evacuating agent include.

• – erste Heizmittel zum Beheizen des Fermenterbehälters;
• – zweite Heizmittel zum Beheizen der Mittel C);
• – dritte Heizmittel zum Beheizen der Verdampfungsmittel und
• – vierte Heizmittel zum Beheizen eines Güllevorratsbehälters.

According to a further advantageous embodiment of the device according to the invention at least one of the following heating means is formed:

• - First heating means for heating the fermenter tank;
• Second heating means for heating the means C);
• Third heating means for heating the evaporation means and
• - Fourth heating means for heating a slurry tank.

through the first, second, third and / or fourth heating means can be in a particularly advantageous manner, a simple process control the fermentation process, as well as the treatment of digestate to reach.

The Heating means, in particular also in connection with a use of waste heat a heat engine, can also be set in isolation, ie in particular without the funds A) to E), especially in connection with biogas plants.

According to one further advantageous embodiment of the device according to the invention the heating means use at least part of the waste heat of the heat engine. This can be done in particular by forming appropriate heat exchangers respectively.

According to one further advantageous embodiment of the device according to the invention are means of implementation a reverse osmosis formed so with the evaporation agent are connectable to the means of conducting a reverse osmosis with the condensate can be acted upon.

So can in a particularly advantageous manner a further cleaning of Condensate take place, which leads to such pollutant levels, that an introduction of the condensate into a receiving water and / or an aggravation the condensate is harmless possible. Under a receiving water is particularly a stagnant or flowing waters, preferred a flowing one waters Understood. By performing The reverse osmosis can thus advantageously to another Cleaning the condensate can be dispensed in a sewage treatment plant. Under a Verregnung in particular the application of the condensate on open spaces, especially on agricultural land. The training of Means of implementation Reverse osmosis is in every biogas plant and thus independent of the rest disclosed features of a corresponding device possible and according to the invention. Especially can the means of implementation a reverse osmosis independently from the agents A) to E) for processing the digestate of a biogas plant formed be.

One Process for the preparation of fertilizer shaped bodies can be carried out in particular in a device according to the invention.

According to one Another aspect of the present invention is a method for Producing plants proposed using fertilizers in the form of at least a fertilizer shaped body produced according to a method of the invention on a usable area is applied.

Under Plants are especially crops and flowers. Under a usable area is in particular an agricultural area, preferably a field too understand. Preferably, the application of the fertilizer takes place before, simultaneously with and / or after planting or sowing the plants. Advantageously, the timing of applying the fertilizer on the nature of the plant, the nature of the soil, the geographical location the useful area and / or the local microclimate to be adjusted.

The details and advantages disclosed for the method according to the invention for the production of a fertilizer shaped article can be transferred and applied in the same way to the device according to the invention. The details and advantages disclosed for the device according to the invention are transferable and applicable in the same way to the method according to the invention. In the following, the invention He will be explained in more detail with reference to the accompanying drawings, without the invention being limited to the embodiments and advantages shown there would. It shows:

1 schematically an embodiment of a device according to the invention.

1 schematically shows an embodiment of a device according to the invention. This includes funds 1 for providing a digestate, which means 2 for providing plant silage, grain and / or water, at least one slurry tank 3 and at least one fermenter tank 4 include. The fermenter tank 4 is with a biogas collection room 5 connected, which with a heat engine 6 is connectable. The in the fermenter tank 4 Biogas produced by fermentation becomes in the biogas collection room 5 collected and in the heat engine 5 implemented, for example, burned and used to generate electricity. The digestate produced during fermentation is stored in the digestate collector 7 collected. This digestate collector 7 is with means 8th for separating the digestate into a solids content and a liquid content connectable. With the means 8th are means 9 connectable to dry the solids content, in which a drying of the solids content takes place.

The means 9 are with means 10 connectable to increase the nutrient content comprising, for example, a mixer, with the fertilizer from a fertilizer reservoir 11 can be mixed in the solids content. The means 10 are with means 12 connected to forming the solids content in fertilizer shaped body. These funds 12 include, for example, a pelletizing and / or extruding tool.

The means 8th for separating the digestate into a solid fraction and a liquid fraction are so with evaporators 13 connectable, that in this only the liquid content is introduced. In these vaporizers 13 there is an evaporation of the liquid fraction to form a concentrate, which is useful as a liquid fertilizer, and a condensate, which discharged after workup to the environment and / or as a starting material in the fermenter tank 4 can be introduced. They are evacuators 14 formed by the to the evaporation means 13 a negative pressure can be applied.

Furthermore, funds 15 designed to perform a reverse osmosis, the so with the evaporation agent 14 are connectable, that the condensate is subjected to a reverse osmosis. The condensate purified by reverse osmosis can be released to the environment. The means 15 to perform a reverse osmosis are with pressure buildup means 21 , For example, connected to a suitably trained pump. They are the first heating means 16 for heating the fermenter tank 4 , second heating means 17 for heating the means 9 for drying the solids content, third heating means 18 for heating the evaporation agent 13 and fourth heating means 19 for heating the manure storage tank 3 educated. The heating of the manure storage tank 3 serves to sanitize the manure. The heating means 16 . 17 . 18 . 19 be over heat pipes 20 about the waste heat of the heat engine 6 heated. In this case, appropriately suitable heat media such as oils, water, etc. in the heat pipes 20 be used and be formed corresponding heat exchanger.

The inventive method and the device according to the invention allow advantageously a sustainable use the digestate in biogas plants. The fertilizer shaped body produced according to the invention sets the nutrients contained advantageously slower free than accordingly unprocessed applied fermentation residues, so that advantageously the over-fertilization of fields and the entry of nutrients, in particular of nitrites, nitrates and phosphates in the groundwater is reduced. In particular, the Use of the waste heat of a with the biogas produced heat engine for drying of the solids content and for heating during further processing the digestate be used. An advantageous development is the cleaning the resulting wastewater directed by means of evaporation and subsequent reverse osmosis.

1

medium for providing a digestate

2

medium for providing silage, grain and / or water

3

Manure storage tank

4

fermenter tank

5

Biogas collection space

6

Heat engine

7

Gärrestsammelbehälter

8th

medium to separate the digestate in a solids content and a liquid content

9

medium for drying the solids content

10

medium to increase the nutritional content

11

fertilizer Clippings

12

medium for forming into fertilizer shaped bodies

13

Evaporation agent

14

evacuating

15

medium to perform a reverse osmosis

16

first heating

17

second heating

18

third heating

19

fourth heating

20

heat conduction

21

Pressure building means

Claims (23)

Process for the production of fertilizer shaped bodies by energy production by means of fermentation in a biogas plant obtained fermentation residues including the following steps: a) provide a digestate with a first nutrient content; b) Separating the digestate in a solids content and a liquid content; c) drying the solids content; d) increasing the nutrient content of the solids content; and e) reshaping of the solids content in fertilizer shaped bodies. The method of claim 1, wherein the step b) a includes mechanical separation. Method according to one of the preceding claims, in the fertilizer molding a Have a dry matter content of at least 85%. Method according to one of the preceding claims, in in step d) the addition of nutrients takes place. A method according to claim 4, wherein a mineral fertilizer is added, the at least one compound comprising at least one of the following substances: - Nitrogen, - Phosphorus and - Potassium. Method according to one of the preceding claims, in after step d) at least one of the following substance proportions is present: - one Weight fraction of nitrogen compounds of up to 25 wt .-%, - one part by weight of phosphorus compounds of up to 20% by weight and - one part by weight of potassium compounds of up to 30% by weight. Method according to one of the preceding claims, in in step e) the solids content is pressed. Method according to one of the preceding claims, in the fertilizer shaped body of a length of 2 cm to 5 cm and a diameter of 0.3 cm to 0.6 cm formed become. Method according to one of the preceding claims, wherein in the biogas plant, a gas mixture is generated which a heat engine ( 6 ) is supplied. A method according to claim 9, wherein at least part of the waste heat of the heat engine ( 6 ) of the gas mixture is used for at least one of the following processes: - step c), - heating at least one fermenter tank ( 3 ), - Heating of manure, and - Evaporation of the liquid fraction. Method according to one of the preceding claims, in the liquid fraction subjected to evaporation to produce a concentrate. Method according to one of the preceding claims, in which creates a condensate, which at least partially a reverse osmosis is subjected. Process according to claim 12, wherein the condensate has at least one of the following constituents: - at most 90 mg / l chemical oxygen demand (COD), - at most 20 mg / l biochemical oxygen demand after 5 days (BOD 5), - at most 10 mg / l Ammonium nitrogen (NH ₄ -N), - not more than 5 mg / l phosphorus and - not more than 18 mg / l nitrogen. Device for producing fertilizer shaped bodies from digestates obtained by energy generation by means of fermentation in a biogas plant, in particular according to the method according to one of claims 1 to 13, comprising A) means ( 1 ) for providing a digestate; B) Means ( 8th ) for separating the digestate into a solid fraction and a liquid fraction; C) means ( 9 ) for drying the solids content; D) Means ( 10 ) to increase the nutrient content in the solids content; and E) means ( 12 ) for forming in fertilizer shaped body. Apparatus according to claim 14, wherein the means B) include mechanical release agents. Apparatus according to claim 14 or 15, wherein means for generating a biogas and at least one heat engine ( 6 ) for implementation are formed at least of parts of the biogas. Device according to one of claims 14 to 16, wherein the means for generating a biogas at least one fermenter container ( 4 ). Device according to one of claims 14 to 17, wherein the evaporation means ( 13 ) are formed for the evaporation of the liquid fraction to form a concentrate and a condensate. Apparatus according to claim 14 to 18, wherein at least one of the following heating means is formed: - first heating means ( 16 ) for heating the fermenter tank ( 4 ); Second heating means ( 17 ) for heating the agent C); Third heating means ( 18 ) for heating the evaporation means and fourth heating means ( 19 ) for heating a manure storage tank. Device according to Claim 19, in which the heating means ( 16 . 17 . 18 . 19 ) at least a portion of the waste heat of the heat engine ( 6 ) use. Device according to one of Claims 18 to 20, in which means ( 15 ) are designed to carry out a reverse osmosis, which with the evaporation agent ( 13 ) are connectable, that the means for performing a reverse osmosis can be acted upon with the condensate. Process for the preparation of fertilizer shaped bodies under Use of a device according to one of claims 14 to 21st Process for the production of plants, whereby fertilizers in the form of at least one fertilizer shaped body produced applied to a useful surface according to a method according to one of claims 1 to 13 or 22 becomes.