DE102013101401A1 - Pretreating horse manure including urine and litter for subsequent fermentation, comprises bringing horse manure with aqueous medium, and circulating a mixture of horse manure and aqueous medium for separation of horse manure and litter - Google Patents

Abstract

Pretreatment of horse manure for subsequent fermentation, comprises: (a) bringing the horse manure with an aqueous medium; (b) circulating a mixture of horse manure and aqueous medium for the separation of horse manure and a litter; (c) introducing a gaseous medium in the mixture of horse manure and aqueous medium, so that the litter flaots; (d) skimming the flaoting litter using a skimming device; and (e) homogenizing the horse manure in the aqueous medium. Independent claims are included for: (1) fermentating the horse manure, comprising pretreating the horse manure with the pretreatment method, and fermenting the pretreated horse manure; and (2) an apparatus for carrying out the method, comprising a container (1) having a bottom side groove (2), a litter-skimming device (3) and at least one gassing device (4, 5) for introducing a gaseous medium.

Description

The invention relates to a method and a device for the pretreatment of horse manure and a fermentation process and a fermentation plant for the fermentation of horse manure.

In view of the dwindling resources of fossil fuels and the simultaneously increasing worldwide demand for energy and resources, the search for alternatives to the use of fossil energy sources is increasing. In addition, the use of fossil fuels is linked to the emission of greenhouse gases, which further increase global climate change. Therefore, there are efforts for some time to limit the emission of climate-damaging gases. For example, the increased use and promotion of renewable energies in Germany has led to a steadily rising share of renewable electricity, with the largest share being generated by wind power, followed by biomass, hydropower and photovoltaics. In order to be able to compensate for overloads in the power grid or even lack of storage possibilities, the electricity must increasingly be able to be generated as needed, which can be done by using biomass.

About half of electricity generated from biomass in Germany is generated by the generation of biogas, which is produced in biogas plants. Renewable raw materials (NaWaRo) and manure have been used to date. The plant technology is specially designed or developed for the use of these raw materials. The use of renewable raw materials, however, has disadvantages, for example the increasing competition for food production and the current monoculture cultivation. Therefore, there is still a need to harness alternative renewable energy sources.

The object of the present invention is therefore to make available a regenerative energy source as an alternative to the use of renewable raw materials or liquid manure.

The object is solved by the subject matters of claims 1, 8, 10 and 15. Advantageous embodiments of the invention are specified in the subclaims.

• a. Zusammenbringens des Pferdemists mit einem wässrigen Medium,
• b. Umwälzens der Mischung aus Pferdemist und wässrigem Medium zur Trennung von Pferdekot und Einstreu,
• c. Einbringens eines gasförmigen Mediums in die Mischung aus Pferdemist und wässrigem Medium, so dass die Einstreu auftreibt,
• d. Abschöpfens der auftreibenden Einstreu mittels einer Abschöpfeinrichtung, und
• e. Homogenisierens des Pferdekots in dem wässrigen Medium.

In a first aspect, the invention provides a method of pre-treating horse manure for subsequent fermentation, the horse manure comprising horse droppings, horse urine and bedding comprising the steps of

• a. Bringing together the horse manure with an aqueous medium,
• b. Circulating the mixture of horse manure and aqueous medium to separate horse manure and bedding
• c. Introducing a gaseous medium into the mixture of horse manure and aqueous medium so that the litter floats,
• d. Skimming of the raising litter by means of a skimming device, and
• e. Homogenizing the horse droppings in the aqueous medium.

With the aid of the method according to the invention, horse manure, an organic residue from horse keeping, which is available locally in considerable quantities, is made available for subsequent fermentation. So far, horse dung has been applied to the fields energetically unused as a manure after a compulsory composting phase of six months prescribed by law. The invention opens up the possibility of recycling this residue, the yield of which is increasingly being rejected by farmers, and which arises in particular in the vicinity of metropolitan areas in an amount which causes disposal problems due to lacking sufficient areas, without any disadvantages in terms of food production or environmental problems, eg through monocultures, emerge. A (co) fermentation of horse manure was previously difficult or impossible in existing biogas plants, because shares such as straw and impurities in the form of e.g. Sand, stones, horseshoes and the like cause significant disturbances of the system components and thus prevent reliable and economical operation.

The pretreatment method according to the invention makes it possible for the first time to actually utilize the potential that horse manure forms for energy production by means of fermentation processes. Horse manure, which has been pretreated by the pretreatment process according to the invention, can be used as a substrate or cosubstrate in a subsequent fermentation process, without any fear of disrupting plant operation. With a number of approx. 900,000 horses and a dung volume per horse and day of approx. 23 to 45 kg, Germany alone has an annual dung volume of about 7.6-14.8 million tonnes. Horse manure is also available throughout the year and probably due to the increasing popularity of equestrian sport and horse husbandry in the future in sufficient quantities. Especially in regions With a high stock of horses, horse manure can make a significant contribution to the energy supply based on renewable energies.

"Fermentation" is the anaerobic degradation of organic matter by microorganisms in an aqueous medium. The degradation proceeds through the four degradation phases of hydrolysis, acidogenesis, acetogenesis and methanogenesis (see, e.g., [2]). The raw materials are thereby converted by biological means into shorter-chain substances and finally converted to biogas, a gas mixture with methane and carbon dioxide as main components. "Fermentation processes" are processes for the fermentation of biomass, a variety of types of processes being known, i.a. single-stage and two-stage or multi-stage, mesophilic and thermophilic processes. A "wet fermentation process" here means a fermentation process in which the substrate to be fermented has a dry matter content (TS) of ≦ 15% by weight.

The term "horse manure" here refers to an inhomogeneous mixture of litter, horse droppings, horse urine and, if necessary, food and housing residues. By "litter" is meant here absorbent material such as straw, wood shavings, wood and straw pellets or granules, e.g. Wood granules, understood. "Long straw" here straw, especially rye and / or wheat straw, with long straight stalks of regular at least 10 cm, preferably at least 15 cm in length, for example 18-20 cm in length understood. By "impurities" is meant manure components that are not part of the litter, the horse droppings, horse urine or if necessary. Of the feed, such as sand, stones, horseshoes, halters, etc.

The nature and composition of horse manure depends on many factors, such as husbandry, feeding or manure. For example, the attitude has an influence on the dung texture. For the most part grazing, for example, sand can make up a considerable proportion of the impurities; in the case of boxing, the amount of litter used is generally higher, for example, than grazing. The season can also exert an influence, for example with regard to the proportion of water. The majority of horses in Germany, especially those that are kept for sports purposes and / or in the vicinity of metropolitan areas, but kept in boxes that are strewn with (long) straw. An exemplary composition for the daily amount of manure per day and horse mentioned above is given in the following Table 1: Table 1: Exemplary amounts of horse manure components in boxing ingredient Quantity [kg per day and horse] excrement 15-25 urine 3-10 straw 5-10 total 23-45

The ratio of manure to uringetränktem straw is at boxing 15:20 to 25: 8, corresponding to a percentage of feces from 43 to 75% by weight. On average, therefore, approximately proportions of about 50% by weight of feces and 50% by weight of wet straw in the horse manure can be assumed [1].

In the method of the invention, the horse manure is first contacted with an aqueous medium, i. the horse manure is added to an aqueous medium, or an aqueous medium is added to the horse manure. As an aqueous medium in particular service water comes into question. It may be, for example, process water obtained from a biological fermentation plant, e.g. Process water from the storage or further processing of digestate. In this way, the process water can advantageously be returned to the fermentation process. It may also be tap water or another aqueous medium.

In a following step, the mixture of horse dung and aqueous medium is circulated to separate the horse droppings from the litter. It has been found that a circulation of the horse manure contained in the aqueous solution is required in order to effect a separation of the litter, for example of straw, from the faeces.

In a further step, a gaseous medium is introduced into the mixture of horse manure and aqueous medium, so that the bedding separated by the faeces drifts up. The gaseous medium may be compressed air or, for example, also oxygen. Also other gaseous, for example Oxygen-free, media come into question. Preferably, the gaseous medium is introduced so that the bedding is captured by the gas bubbles and carried to the surface of the aqueous horse manure mixture (aqueous medium plus horse manure) and / or a flow is caused in the aqueous horse manure mixture which spreads the bedding to the surface of the aqueous manure Horse manure mix brings.

In a further step, the bedding litter is skimmed off by means of a suitable skimming device. This can be done, for example, with a rake, which detects and discharges the raising litter.

The remaining horse droppings are homogenized in the aqueous medium, i. as finely and evenly distributed. This homogenization can be done in an advantageous manner, for example by the circulation of the aqueous horse manure mixture. It has been found that the horse droppings largely dissolve in circulation in the aqueous medium or can be distributed finely.

In a particularly preferred embodiment of the method according to the invention, the circulation of the mixture of horse manure and aqueous medium and the homogenization of the horse droppings in the aqueous medium is effected by introducing the gaseous medium into the mixture of horse manure and aqueous medium. In this embodiment of the method according to the invention, the gaseous medium, for example compressed air, introduced into the aqueous horse manure mixture, that this is circulated and thereby at the same time a dissolution of the horse droppings and a flooding of the bedding is effected. For example, this can be done by a circulating flow in the aqueous horse manure mixture is generated by the introduction of the gaseous medium, which feeds off the horse droppings and auftrreibende litter, such as straw, the skimming device, such as a rake.

In a further preferred embodiment of the pretreatment method according to the invention, the horse manure is combined with an amount of aqueous medium such that the mixture after homogenization has a dry matter content of ≦ 15% by weight, preferably ≦ 12% by weight or ≦ 10% by weight, particularly preferably ≦ 9% by weight or ≦ 8% by weight. As a result, the pretreated horse manure can then be advantageously subjected to a wet fermentation process.

With the method according to the invention, a wide range of horse manure compositions can be pretreated. The pre-treatment process is particularly suitable if the litter consists of long straw or comprises long straw. In an advantageous embodiment of the method, the skimmed long straw can be recycled by crushing it and fed back into comminuted form, for example, the fermentation process. For example, it may be mixed again after the pretreatment of the homogenized mixture or separately, if appropriate together with the homogenized horse manure, introduced into a subsequent fermentation process. The comminution of the straw is primarily to make this substrate eligible, i. pumpable, to do. The straw is therefore particularly advantageously comminuted to a neck length of ≤10 mm.

Any contaminants present in the horse manure such as sand, stones and the like are preferably separated from the mixture of horse manure and aqueous medium. In this case, the usually higher density and / or inertia of the contaminants is preferably utilized, and a deposition, for example a gravitational separation, is carried out on this basis. Sand can be separated, for example, by the method of a ventilated sand trap. For example, the gaseous medium, e.g. Compressed air, are introduced so that sand, stones, etc. sink due to gravity down, while lighter components such as the litter and Kotbestandteile remain or hover.

The process can be operated batchwise or continuously. In continuous operation, it may be advantageous if the mixture of horse manure and aqueous solution flows through a container in the longitudinal direction and in the mixture by entry of the gaseous medium, a transverse thereto circulating flow is generated. The flow causes the litter to be raised and advantageously drives the bedding in the direction of the skimming facility. The step of separating existing contaminants may be downstream in the case of sand in the direction of flow. For example, a sand trap may be provided at the end of the container.

• a. Vorbehandelns von Pferdemist mit dem Vorbehandlungsverfahren nach dem ersten Aspekt der Erfindung, und
• b. Vergärens des vorbehandelten Pferdemistes.

In a second aspect, the present invention also relates to a process for the fermentation of horse manure, comprising the steps of

• a. Pretreatment of horse manure with the pretreatment method according to the first aspect of the invention, and
• b. Fermenting the pretreated horse manure.

The step of fermenting the pretreated horse manure may be carried out by any fermentation process, preferably a wet fermentation process. The pretreated horse manure can be supplied as a monosubstrate or cosubstrate. In a one-step process, the pretreated horse manure is preferably added directly to the fermenter, preferably fed to the first stage in multi-stage processes. Skinned and shredded long straw can be fermented together with the pre-treated horse manure.

In a third aspect, the present invention for carrying out the method according to the first aspect of the invention, that is a device for pretreatment of horse manure for a subsequent fermentation. The device according to the invention comprises a container with a bottom-side channel, a bedding-skimming device and at least one gassing device for introducing a gaseous medium, for example compressed air. The litter skimming device is preferably arranged on one side of the container. In particular, in the case of a continuous treatment, the litter skimming device is preferably arranged on one side of the container, on which a calming zone, that is to say a container zone with a reduced flow velocity of the medium flowing through, is formed. For example, the container may be in the form of a grit trap, as is generally known in the art for the mechanical clarification of wastewater (see, e.g., [3], [4]). Instead of a grease trap, however, a litter skimming device is provided in the device according to the invention, with the aid of bedding can be skimmed off in a suitable manner.

In the device according to the invention, the gassing device for introducing a gaseous medium is preferably arranged such that the introduction of a gaseous medium causes a circulation of an aqueous medium in the container. The gassing device may, for example, be arranged just above the channel, as in the case of a ventilated sand trap on one side of the container. Fumigation on one side of the container induces a secondary flow through the rising gas bubbles creating a rotating vortex within the container which holds organic particles in suspension while the sand is sinking. The sand-contaminated medium flows through the container lengthwise and is thereby freed from the sand. Optionally, an additional evacuation means may be provided, with the aid of which the settled sand can be removed from the channel.

In one embodiment, the gassing means may be disposed on a side of the container opposite to the container side on which the bedding skimming means is disposed. Alternatively or additionally, however, the gassing device can also be arranged on the side of the container on which the litter skimming device is also arranged. In this case, the gassing device is preferably arranged in the upper region of the channel or in the transitional region between the channel and the overlying container part, in such a way that the gas bubbles emerging from the gassing device cross the channel during the operation and ascend on the opposite side of the container. In this way, the rising gas bubbles form a barrier for lighter media components, which can be prevented, for example, that horse droppings or wet straw sinks into the gutter area.

In a further embodiment, for example, a channel closure device can also be provided, that is to say a closure device with the aid of which the channel can be closed at least temporarily with respect to the overlying container part. This can be advantageous, for example, in the sentence mode.

The litter skimming device is preferably designed as a rake, for example as a bar screen with circulating cleaning rakes. For example, it may be a mat circulating on rollers, into which pins of metal, plastic or other materials are embedded, the pins projecting outwardly and engageable with straws. The litter skimming device may be associated with a catcher that catches skimmed litter. Optionally, in addition, a stripping means may be provided, with the aid of which the skimming device can be freed from adhering straws. This may be, for example, a fixed or rotating brush.

In a particularly preferred embodiment of the device according to the invention, which is particularly well suited for continuous operation of the method according to the invention, the container in the flow direction of the mixture of horse manure and aqueous medium in three sections A, B, and C is divided, wherein the first container section A a horse manure and aqueous medium loading device comprising in the flow direction of the container section A container section B the bedding Abschöpfeinrichtung comprising in the flow direction of the container section B subsequent container section C the channel, and wherein the gassing device extends over the container sections A to C. The gassing device can be designed, for example, in the form of a loop. In this embodiment, the device according to the invention is divided into sections. In the first container section A is a task device, such as a hopper. Here, the horse manure and the aqueous medium, such as process water, are added to the container, wherein the gassing ensures mixing. The subsequent container section B has the litter skimming device, so that in this container section, the mixture flowing through the container of horse manure and aqueous medium of bedding, such as straw, can be exempted. In the subsequent container section C, a channel is provided in which, for example, sand and other contaminants can be collected. The gassing device ensures a circulating flow in the container, which runs transversely to the flow direction of the mixture, which ensures equalization (homogenization) of the horse manure in the aqueous medium. At the end of the container section C is then a uniform litter and impurities freed aqueous horse manure substrate, which can be fed to a fermentation plant.

In a fourth aspect, the invention relates to a fermentation plant comprising a device according to the third aspect of the invention. The device according to the invention can be connected, for example, to a fermenter of a fermentation plant via lines.

In the following the invention will be described in more detail by means of figures and an embodiment purely for illustrative purposes. It shows:

1 Schematic cross section through an embodiment of a device according to the invention.

2 Schematic plan view of an embodiment of a device according to the invention for continuous operation.

1 shows a schematic cross section through an embodiment of a device according to the invention. The device comprises a container 1 which has the shape of a sand trap here, with a baffle or the like is not present here. The flow direction, not shown here in the case of a continuous mode of operation would be perpendicular to the paper level. The container 1 tapers in cross-section downwards and has a groove on the bottom side 2 on. The container 1 points to a container side 14 a calming zone 12 on, that is, a relatively shallow leaking container zone with a reduced flow rate of a medium passing through. In the calming zone 12 emerges a trained here as a rod rack litter skimming 3 under the surface 8th the mixture of horse manure and aqueous medium, wherein the bedding skimmer 3 can be tilted by an angle β relative to the vertical, as in the figure by showing two positions of the bedding-skimming device 3 is indicated. The angle β may be 10-20 °, for example. The litter skimming device 3 includes one on rollers 17 circumferential mat 15 with outwardly projecting rakes 16 , One on the side 14 provided catching device 6 catches skimmed litter, for example straw. Skimmed litter may optionally be further processed, for example, crushed. Between collecting device 6 and litter skimming facility 3 can be a scraping device 7 be provided, for example in the form of a brush, if necessary to ensure that the litter skimming device 3 is freed from adhering litter. A gassing device 5 is on the tank side 14 with the litter skimming device 3 opposite tank side 13 laterally above the gutter 2 arranged. Alternatively or additionally, a gassing device 4 on the container side 14 , ie the side with the litter skimming device 3 be arranged. The information on the orientation with regard to the container sides here refers to the gutter 2 ie an in 1 The device lying to the right of the middle of the channel becomes the right side of the container 14 , one in 1 On the left side of the middle of the channel, the left-hand side of the container is located 13 attributed. The fumigation device 4 is here in the upper part of the channel 2 or in the transition region between the gutter 2 and the upper container part 9 arranged laterally and / or is operated so that of the gassing 4 rising gas bubbles 10 the gutter 2 or cross the transition area and on the opposite side of the container 13 rising up. gas bubbles 10 that of the fumigation device 5 and / or the gassing device 4 ascend, create an in 1 by arrows 11 indicated circulating flow, which in continuous operation transverse to the flow direction of the medium through the container 1 runs. The flow is on the tank side 13 , the bedding skimmer 3 opposite, upwards, on the container side 14 with the litter skimming device 3 down, ie towards the tank bottom or gutter 2 , In this way, raising bedding in the direction of the calming zone 12 and the bedding skimmer 3 driven, where it can be skimmed off. With the fumigation device (s) 4 . 5 is preferably compressed air with suitable pressure in the container 1 brought in.

2 shows a preferred embodiment of the device according to the invention in plan view. This embodiment is particularly well suited for a continuous operation of the method according to the invention. The container 1 is elongated and in the direction 19 the through the container 1 flowing mixture of horse manure and aqueous medium into three sections A, B and C. The container section A has a feeding device 18 on, which may be for example a filler neck or the like. Here, the horse manure and the aqueous medium, preferably process water from a subsequent fermentation plant, in the container 1 are given. A here designed as a perforated loop gassing 5 Here on the bedding skimmer 3 opposite tank side 13 is arranged and extends over all container sections A, B and C, ensures a thorough mixing and homogenization of horse manure and aqueous medium and for the buoyancy of litter. In the following container section B is on the fumigation 5 opposite tank side 14 a litter skimming device 3 , which may be formed as a bar screen arranged. The following container portion C has, for example, the cross section of in 1 illustrated container 1 and with it a gutter 2 which can be used to collect sand and other contaminants. While the mixture of horse manure and aqueous medium passes through the tank sections A, B and C, it finds continuously by means of the gassing device 5 and the circulating flow caused by it, homogenization of the horse droppings takes place in the aqueous medium, so that a homogenised liquid substrate results, which can advantageously be fermented in a subsequent fermentation plant, for example a wet fermentation plant, as substrate or cosubstrate.

embodiment

With the help of a device, as in 1 Batch experiments with horse manure on a pilot plant scale were carried out. Tap water was used as the aqueous medium. The aeration was carried out by 3 Nm ³ / h at a pre-pressure of 1 bar. The pH of the pure water was 8.01. The TS or oTS contents (TS = dry substance, oTS = organic dry matter) were after DIN 38414-S2 respectively. DIN 38409-H1-3 determined in triplicate.

The device was first filled with 600 liters of water. The temperature was 15.6 ° C at the beginning of the experiment. Subsequently, 5 kg of wet straw and 5 kg of sand interspersed horse apples from the riding track were filled into the device. 13 minutes after the start of filling, the straw was discharged. The discharge process was carried out for 15 minutes and the straw collected in a container. The initially closed by means of a plastic plate Sandfangrinne was now open. The aeration was carried out to deposit the sand for an additional 10 minutes.

Subsequently, the liquid phase was drained. A sieve at the outlet prevented leakage of the remaining straw in the liquid phase. This was also skimmed off by means of another sieve and recorded separately. The predominantly solid sediment in the sand gutter was removed by a shovel and weighed out. The remainder of the sediment was rinsed out.

Modeling showed that both the straw and the sand were separated from the liquid phase. To determine the separation efficiency of the straw and the sand, the sample characteristics for balancing and evaluation listed in Table 2 were determined. Table 16: Sample parameters for commissioning component Quantity [kg] TS [%] OTS from TS [%] Wet straw 5 33.46 ± 2.00 89.20 ± 0.16 Dry the straw 80.81 ± 2.32 94.14 ± 0.62 Horse apples with sand 5 38.08 ± 1.52 32.54 ± 0.21 Horse apples without sand nb 20.97 ± 0.04 92.22 ± 0.03 Halle sand nb 95.04 ± 0.13 4.65 ± 0.08 Washed straw 10.5 14.02 ± 1.22 95.19 ± 0.05 Sand trap 8th 17.69 ± 0.46 36.20 ± 0.44 Sand trap liquid 9 0.57 ± 0.04 Bnm liquid phase nb 0.09 ± 0.03 Bnm Horse apples in liquid phase 0.15 15.67 83.31 ± 0.23 Straw in liquid phase 0.44 10.24 92.93 ± 0.11 nb = not determined, Bnm = determination not possible

• 1. Eingefülltes Stroh: 5 kg × 33 – 81 % TS = 1,65 – 4,05 kg Stroh
• 2. Ausgetragenes Stroh: 10,5 kg × 14,0 % TS = 1,47 kg Stroh
• 3. Strohmenge in der Flüssigphase: 0,44 kg × 10 % TS = 0,04 kg Stroh
• 4. Differenz: 0,14 – 2,54 kg

The balance of straw and straw discharged in the system was calculated on the basis of the rounded dry matter content of the filled and discharged quantities of straw as shown in Table 2:

• 1. Stuffed straw: 5 kg × 33 - 81% TS = 1.65 - 4.05 kg straw
• 2. Thrown straw: 10.5 kg × 14.0% TS = 1.47 kg straw
• 3. Volume of straw in the liquid phase: 0.44 kg × 10% DM = 0.04 kg straw
• 4. Difference: 0.14 - 2.54 kg

The difference arises from the organic matter adhering to the straw, or from sand accumulations that have been transferred to the liquid phase and sediment. Since the unsprayed straw was skimmed off in the liquid phase or prevented from escaping and only isolated straws were to be found in the sand trapping channel, an almost complete separation of the straw takes place. Assuming that the straw content in the liquid phase and the discharged straw content together give the total mass of straw, the separation efficiency is 1.47 kg / (1.47 kg + 0.04 kg) ≈ 97.4%. The remaining straw shares in the sand gutter were small.

The amount of sand added and removed from the device was determined by determining the inorganic constituents of the horse manure. For this purpose, the rounded oTS contents from Table 2 without the standard deviation were used. First, the sand content was determined in the sand-contaminated horse apples.

The pure and fresh horsepox from the box contained no sand and had a TS content of 21.0% and an OTS content of 92.2%. The oTS content of the fresh mass was thus 19.4%. The pure hall sand had a TS content of 95.0% and an OTS content of 4.7%. The oTS content of the fresh mass was therefore 4.5%. The mixture of hall sand and horse apples filled into the system had a TS content of 38.1% and an OTS content of 32.5%. The oTS content of the fresh mass is then 12.4%. Based on a linear relationship, a sand content of 68.2% is found in the filled horse-and-horse sand mix compared to the OTS content.

Accordingly, by the 5 kg of sand polluted horse apples with a TS content of 38.1% and 69% sand content in the dry matter 1.31 kg of sand have been introduced into the system The solid fraction in the sand trap, which was removed by means of a blade, had an OTS content of 36.2%. According to a linear interpolation, this results in a sand content of 64.4%. With a sediment mass of 8 kg, a TS content of 17.7% and a sand content of 64.4% results in a sand mass of 0.91 kg. The separation efficiency of the sand trap, i. The deposited sand mass in relation to the amount of sand deposited was thus 0.91 kg / 1.31 kg ≈ 69.5% in trial operation.

A balance of the organic components gave the following result:
When accounting for the straw carry, a residual difference of 0.14 - 2.54 kg was found, which was attributed to the contamination and buildup of the straw. In addition to the straw were also abandoned sand-contaminated horse apples. Based on 5 kg fresh mass, 38.1% DM content and 31.8% organic (sand content 68.2%) results in 0.61 kg of organics.

The grit was taken from 8 kg of sediment with a TS content of 17.7% and 35.6% organics (sand content 64.4%). This is 0.50 kg of organics. TS content of 0.09% for the liquid phase has been determined. The water supplied to the substrate was neglected. The container contained 600 liters of water. The result is a dry mass of 0.54 kg, which was discharged through the liquid substrate. The dry weight of the remaining in the liquid phase horse apples amounts to 0.02 kg.

In total, 0.61 kg of organic matter and 0.14-2.54 kg of adherence were added to the straw. At the end of the experiment, 0.50 kg of organics were removed from the sand trapping channel and 0.54 kg of dry matter left the preparation via the liquid substrate. In addition, 0.02 kg unresolved horse apples.

Horse manure could be suitably treated by the method of the invention. There was a dissolution of the horse apples and the necessary detachment of attachments on the straw. The straw could be separated and discharged with high separation efficiency. The same applies to sand.

literature

• [1] Powrosnik, A.-M. (2011): Investigation of process stability and mass balance in monofermentation of grass clippings and horse manure. Master thesis. University of Anhalt (FH). FB Applied Biosciences and Process Engineering ,
• [2] Kaltschmitt; strings; Wiese (2012): Renewable Energies. System technology, economy, environmental aspects. Berlin: Springer. ISBN: 978-3-642-03248-6
• [3] DIN 19551-2, 2002: Wastewater treatment plants Rectangular tanks Part 3: Sand traps with suction and shield scrapers; Designs, main dimensions, equipment ,
• [4] DWA (German Association for Water, Wastewater and Waste eV) (2008): Sand trap requirements, systems and design. Working Report of the DWA Technical Committee KA-5 "Absetzverfahren". In: Correspondence Wastewater (55 (5)), 508-518 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• DIN 38414-S2 [0037]
• DIN 38409-H1-3 [0037]

Claims (15)

A method of pretreating horse manure for subsequent fermentation, the horse manure comprising horse droppings, horse urine and bedding comprising the steps of a. Bringing together the horse manure with an aqueous medium, b. Circulating the mixture of horse manure and aqueous medium to separate horse manure and bedding c. Introducing a gaseous medium into the mixture of horse manure and aqueous medium so that the litter floats, d. Skimming of the raising litter by means of a skimming device, and e. Homogenizing the horse droppings in the aqueous medium. The method of claim 1, wherein the agitation of the mixture of horse manure and aqueous medium and the homogenization of the horse droppings in the aqueous medium is effected by introducing the gaseous medium into the mixture of horse manure and aqueous medium. Method according to one of claims 1 or 2, wherein the horse manure is brought together with such an amount of aqueous medium that the mixture after homogenization has a dry matter content of ≤ 15%, preferably ≤ 12% or ≤ 10%, more preferably ≤ 9% or ≤ 8%. Method according to one of the preceding claims, wherein the gaseous medium is compressed air. Method according to one of the preceding claims, wherein the litter consists of long straw or long straw, and the skimmed long straw is comminuted to a neck length of ≤ 10 mm. A method according to any preceding claim, wherein the horse manure comprises contaminants such as sand, stones and the like, and wherein the contaminants are separated from the mixture of horse manure and aqueous medium due to density and / or inertial differences. Method according to one of the preceding claims, wherein the method is operated batchwise or continuously. Process for the fermentation of horse manure, comprising the steps of a. Pretreatment of horse manure with the pretreatment method according to any one of claims 1 to 7, and b. Fermenting the pretreated horse manure. The method of claim 8, wherein skimmed and shredded long straw is fermented together with the pretreated horse manure. Apparatus for carrying out the method according to one of claims 1 to 7, comprising a container ( 1 ) with a bottom groove ( 2 ), a bedding skimmer ( 3 ) and at least one gassing device ( 4 . 5 ) for the introduction of a gaseous medium. Apparatus according to claim 10, wherein the fumigation means ( 4 . 5 ) is arranged for introducing a gaseous medium such that the introduction of a gaseous medium causes a circulation of an aqueous medium in the container. Device according to one of claims 10 or 11, wherein the litter skimming device ( 3 ) is designed as a rake, preferably as a bar screen with circulating cleaning rakes. Apparatus according to any one of claims 10 to 12 for the continuous pre-treatment of horse manure, the container ( 1 ) in the flow direction of the mixture of horse manure and aqueous medium into three sections (A, B, C), wherein the first container section (A) comprises a dispensing device for horse manure and aqueous medium, the container section in the direction of flow (A) subsequent container section ( B) the litter skimming device ( 3 ), in the flow direction of the container section (B) subsequent container section (C) the channel ( 2 ), and wherein the gassing device extends over the container sections A to C. Device according to one of claims 10 to 13, wherein the gassing device ( 4 ) with respect to the middle of the gutter ( 2 ) to the container side ( 14 ) with the litter skimming device ( 3 ) in the upper area the gutter ( 2 ) or in the transition area between the channel ( 2 ) and the overlying container part ( 9 ) is arranged. A fermentation plant comprising a device according to any one of claims 10 to 14.

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