WO1986000293A1

WO1986000293A1 - Method and plant for continuously producing biological humus-forming fertilizer

Info

Publication number: WO1986000293A1
Application number: PCT/EP1984/000203
Authority: WO
Inventors: Werner HÜBNER
Original assignee: Inprohold Establishment
Priority date: 1982-12-30
Filing date: 1984-06-29
Publication date: 1986-01-16
Also published as: EP0189398A1; DE3248703A1

Abstract

The method is used for the continuous production of a biological humus-forming fertilizer free of germs and medicinal residues, from animal and agricultural waste, and biogas by bacterial fermentation. The treatment for the preparation and anaerobic bacterial fermentation of the starting material mixed with starting material mixed with a liquid into a continuous and uniform flow is achieved in two steps. In the first step, life conditions are created within the suspension which are best adapted to cultures of mesophilic bacteria causing a hydrolysis and acidification of the starting material, particularly by heating at about 30o-40oC and, at predetermined time intervals, first part of the bacteria-containing liquid and at the end of the treatment optionally the other part is removed from the suspension and is added to the new starting material to be introduced and/or to the suspension. In the second step, the product released preferably partially from the liquid of the first step is mixed with the bacteria-containing liquid extracted from the suspension in the second step and life conditions best adapted to the cultures of thermophilic bacteria achieving the fermentation are created within said liquid, particularly by heating at a temperature of about 50o-60oC. The gases generated in both steps are sucked and collected; at least one portion is divided into separate jets and introduced into the suspension, the remaining being separated into CO2 gas and CH4 gas, the first one being divided into separate jets and again introduced into the suspension, the second one being used to cover the general energy requirement for implementing such method up to the obtention of the final product. The plant for implementing such method comprises two covered vat-like containers (11, 12) of which the bottom (15) presents a continuous slope of at least 2% from the loading end to the discharge end.

Description

Method and device for the continuous production of biological, humus-forming fertilizer

The invention relates to a method and a device to be preferably used for this, for the continuous production of germ-free and drug-free, biological, humus-forming fertilizer from primarily animal and optionally also agricultural waste products and biogas by bacterial fermentation.

It is already known to obtain biogas from the waste materials from animal husbandry and agriculture which are considered by anaerobic fermentation, a fertilizer being obtained as a by-product. With these processes, gas production is in the foreground and the fertilizer is a by-product. If the focus of the known processes is on gas production, it is because they are used to try to ensure the economy as far as possible. However, the economic viability of such processes is only guaranteed if bulk buyers ensure that the gas produced is taken over constantly and immediately over a long period of time. However, this cannot be realized for various reasons, which is why such processes are only used in relatively small plants, the gas generated being used to cover the energy requirements of the company's own operation and the fertilizers for its own lands.

Processes and systems of the type under consideration which have been used industrially have not hitherto become known. Insofar as plants exist for the production of biogas, these are composed of apparatuses which are complex with regard to their construction and operation. With these, the accruing

Waste processed in a container, which requires complicated control mechanisms. The known systems are in no way a model for large-scale industrial applications, because the quantities to be managed per unit of time are so immense that paths must necessarily be followed which lead to a specific task. Waste products from industrial livestock farming, especially with regard to poultry of all kinds, occur in enormous quantities and cause considerable environmental problems. Even if these waste products were stored temporarily for a certain period of time, no guarantee could be given that they could then be safely applied to the fields as fertilizer. They still contain germs and drug residues that can have harmful effects on animals and humans. Now that the large quantities of such waste products have to be accommodated somewhere, they are often applied in relatively large quantities which are too large, ie the fields in question are over-fertilized. Apart from the fact that such fertilizers are only tolerated by certain plants, they take the nutrients from the. Only a fraction of fertilizer; the rest is carried into the ground by the rainwater and reaches the groundwater at some point.

It is in the general interest that the waste materials under consideration are treated or treated and made usable in such a way that they can be used without hesitation and are able to replace chemical artificial fertilizers at least to a considerable extent. Fertilizer of the type to be produced is therefore based on biological, natural starting materials and offers the advantage

not only to contain all the essential components of fertilizer that plants need, but also important trace elements. In addition, the fertilizer in question is particularly suitable as a humus former, which improves the arable soil.

The invention is based on the object of proposing a method which can be used on a large industrial scale, allows the large amount of throughput to get by with the smallest possible systems and minimal equipment expenditure and enables economical operation. In contrast to previous methods, the focus of the technology should be on the production of biological fertilizers, the inevitable amounts of biogas only being used to cover the energy requirements of the plant or the entire plant, both in terms of thermal energy and also electrical energy and possibly the energy required for the operation of vehicles.

Another object of the invention is to create a continuously operating method, in contrast to the previously known discontinuous methods when using individual containers.

To achieve this object, it is proposed according to the invention to use those measures which are specified in claim 1. Further expedient embodiments of the method proposed according to the invention can be found in the subclaims. The characteristics of the device which is particularly suitable for carrying out the method proposed according to the invention are evident from the claims relating to the device. Further details and features are explained in more detail below,

f OMPI in particular on the basis of the exemplary embodiment of a particularly expediently designed device shown in FIGS. 1 and 2. Show it:

1 shows a longitudinal section through a part of the plant in which biological fertilizer can be produced by the method according to the invention;

Fig. 2 is a plan view of a schematically illustrated system in a particularly advantageous, space-saving embodiment.

1, the device consists of two elongated troughs 11 and 12, in each of which one of the two process stages takes place.

In principle, the two troughs and the devices assigned to them are essentially the same; they differ primarily in their length because the dwell time of the floods treated in them differs; therefore, the trough 12 for the second stage is about 1 1/2 to 2 times longer than the trough 11 for the first stage.

The troughs 11 and 12, which are advantageously constructed from reinforced concrete, are provided with a gas-tight cover 13 and 14, respectively. Each of the troughs is divided into sections A, B, C, D, etc. The bottom 15 of the troughs 11 and 12 is inclined downward in the flow direction within each section A, B, C, D, etc., namely by an angle of at least 2 to 3. At the end of each section A, B, C, D etc. there is a threshold 16, in the niche of which there is an extraction pipe 17 provided with openings,

by means of which a portion of the liquid from the suspension can be drawn off by means of the pumps 18.

Furthermore, there are in the bottom 15 and in the side walls 19 of the troughs 11 and 12, respectively, pipes 20 with nozzles 21 which open into the interior of the troughs 11 and 12 in order to introduce gas into the slurry in them. For this purpose, the pipes 20 are connected to the distributor pipe 22.

At the end of the feed, at least one feed line 23 opens into the trough 11 or 12 into a distribution channel 24 located therein, from which the material introduced and possibly mixed with further liquid reaches the trough 11 or 12 and the mass flow at its end rear end is added. At the discharge end there are several discharge funnels 26 or the like in the rear trough wall 25. open into an exhaust duct 27 for the finished ^'treated slurry which filtered off with suction by means of the pump 28 and a centrifugal separator is supplied to 29th

At the loading end of the second trough 12, the feed line 30 for supplying the partially watered mass from the first process stage opens into a distribution channel 31 in which it is mixed and mixed with liquid from the second process stage and then to the mass flow in the trough 12 the rear end is added.

As can be seen from FIG. 2, the troughs 11 'and 12' are zigzag-shaped; This is achieved in the simplest way by arranging guide walls 42 offset from one another in a correspondingly wide channel 41

O PI ^{■> WIPO} are so that the mass flow takes a serpentine or zigzag path through the two stages I and II.

The operation of the device or system shown in the drawing and described above is carried out in the manner specified in the process claims as follows.

The starting product is, for example, the chicken manure that accumulates on a large scale in chicken farms, which is crushed and suspended with the addition of water. Instead of chicken droppings, it goes without saying that all other excrement from animal husbandry can be used, even if they are mixed with litter material, which is broken down into small particles during comminution.

The starting material thus obtained is introduced through the feed line 23 into the trough 11 of the first process stage. It first reaches the distributor channel 24, in which it is mixed with liquid containing bacteria, which liquid has been removed from the suspension in the trough 11 by means of the suction pipes 17. Furthermore, at the level of the liquid level of the suspension, there is an inoculation trough 32, by means of which new bacterial cultures or those recovered from the suspension are also added to the suspension. From the distributor channel 24, the supplied starting material reaches the trough 11 at the loading end and is added to the mass flow moving in this at the rear end, in each case in an amount corresponding to the sludge drawn off at the discharge end. During the passage of the suspension through the trough 11, it is whirled up by gas introduced into it and, in a way, circulated along certain cross-sectional profiles. Due to the numerous gas bubbles that rise in the slurry, the surface is enlarged in an unusual manner, which results in a rapid preparation of the slurry in the process step.

The gas is supplied through the pipelines 20 arranged in the trough bottom 15 and in the trough side walls 19, from whose nozzles 21 the gas is introduced into the suspension in the form of jets. As a result of the gradient of the bottom sections A, B, C, D etc. and the resulting hydrostatic and hydrodynamic conditions in the trough, the suspension floats through the trough, the residence time of the mass supplied at a particular point in time always due to the uniform movement of the mass flow is equal to.

In the first stage of the process, i.e. A certain, albeit small amount of gas is already formed in the trough 11. which consists of C0 and CH. consists. This gas is drawn off via the pipeline 33 and fed to a collecting container.

You can either use this gas mixture to blow it into the mass flow in the trough 11 via the pipes 22 and 20. Since it is advisable to separate the CH, gas obtained from the C0 gas for further use, the C0 gas gas is advantageously introduced into the mass flow in the first process stage instead of the gas mixture.

blow, especially since this promotes the preparation of the mass for fermentation in the second stage of the process.

At the discharge end of the trough 11, the suspension is drawn off via the discharge funnel 26 and the discharge line 27 by means of the feed pump 28. The suspension is expediently freed of liquid by means of centrifuges to a certain degree which proves to be expedient and which, since it contains bacteria to a considerable extent, is then returned to the trough 11 via the pipeline 34. The mass largely freed from liquid and prepared in the first process stage is then fed via the pipeline 35 to the distributor trough 31 in the second trough 12, in which it is mixed with the liquid removed from the suspension in the trough 12. The suspension flows out of the trough 31 into the trough 12, where it is added to the rear end of the mass flow at the end of the entry. The design of the second trough 12 is the same as that of the first trough 11. The only difference between the two troughs is that the second trough 12 is about 1 1/2 to 2 times longer than that Trough 11.

The fermentation of the biomass contained in the suspension takes place in trough 12, biogas being produced to the desired extent. To a small extent, CO 2 gas is also produced in this process stage. The gas mixture is drawn off and likewise fed to the above-mentioned collecting container. In each case, only as much biogas is generated as is necessary in order to have enough process heat on the one hand and an energy carrier to cover the energy requirements of the entire operation on the other hand.

At the end of the discharge, after the fermentation of the biomass has been completed in the second process stage, the suspension is drawn off and, after a brief heating to at least 70 ° C. or more, the liquid is largely removed by means of centrifuges. The moist and still hot mass is then sent through a drying plant. in which the residual moisture is withdrawn to a certain desired percentage. The mass obtained in this way is the finished, suitable for commercial biological fertilizer, which is free of germs and other undesirable residues. The treatment in the manner described also means that he cannot follow up, ie that he is and remains odorless.

v? ϊ

Claims

A nsp ^' re

Process for the continuous production of germ-free and medicament-residue-free, biological, humus-forming fertilizer from primarily animal and possibly also agricultural waste products and of biogas by bacterial fermentation, characterized in that the anaerobic bacterial treatment and fermentation treatment of the liquid material in a continuously and uniformly moving mass flow is carried out in two stages, in the first stage in the suspension the mesophilic bacterial cultures effecting hydrolysis and acidification of the starting material are optimally adapted, in particular by heating to about 30 to 40 ° C. and, after certain periods of time, the suspension is first removed from the liquid containing bacteria and, at the end of the treatment, the other part, if necessary, and the starting material to be newly supplied and or or the suspension is added, and in the second stage

preferably partially liquid-freed product of the first stage is mixed with the bacterial liquid withdrawn from the suspension in the second stage and this is used to create living conditions which are optimally adapted to the thermophilic bacterial cultures causing the fermentation, in particular by heating to about 50 to 60 ° C. the gases occurring in both stages being drawn off and collected, at least some of which, divided into individual jets, being reintroduced into the suspension and the remaining part being separated into CO 2 gas and into CH 2 gas, in which the former divided into individual jets, fed back into the suspension and the latter is used to cover the entire energy requirement for carrying out the process until the end product is obtained.

2. The method according to claim 1, characterized by the following measures in the first process stage:

a) the starting material consisting of animal waste products, in particular animal excrement and, if appropriate, agricultural waste products, is comminuted and water and / or the suspension removed in a later stage of the process is added until the proportion of dry matter is about 6 ° a 'corresponds to 16%, preferably approximately 7% to 12%, and is then continuously fed to the uniformly moving mass flow at its rear end;

OMPI «. * Y ^ IO b) the suspension is inoculated with an anaerobic, esophilic bacterial culture causing hydrolysis and acidification, mixed thoroughly with it and subjected to a treatment process for the fermentation in the second process stage;

c) the suspension is heated to a temperature of approximately 30 to 40 ° C., preferably approximately 32 to 35 ° C., and is kept at this temperature level for a period of approximately 1 to approximately 4 days, preferably approximately 2 days;

d) after the expiration of about a third and, if appropriate, a further third of the treatment time, the suspension is taken up with vaccinated liquid containing bacteria, which is added to the suspension immediately before or during and, if appropriate, after it has been supplied to the mass flow;

_? e) the gases produced during the treatment period (C0 and CH) are deducted and collected.

f) after the treatment time has elapsed, the liquid containing bacteria is largely removed from the suspension and added to the suspension at the beginning of the mass flow.

3. The method according to claim 1, characterized by the following measures in the second process stage:

g) the product largely freed from the liquid at the end of the treatment in the first process stage is continuously fed to a second, uniformly moving mass flow at the rear end thereof, which optionally contains new anaerobic, thermophilic bacterial cultures and / or the mass flow on one or added and mixed with bacteria-containing liquid taken from several cross sections until the proportion of dry matter is about 6% to 18%, preferably about 8% to 12%;

h) the suspension is heated to a temperature of about 50 to 60 C, preferably about 52 to 55 C, and kept at this temperature level for a period of about 3 to 6, preferably about 4 days;

i) after the expiration of about a third and possibly a further third of the treatment time, the suspension is removed with seeded vaccine liquid which is added to the suspension immediately before or during and, if appropriate, after it has been supplied to the mass flow;

k) the gases generated during the treatment period (C0 ₂ , CH,) are drawn off and collected;

i) after the end of the treatment time, the liquid containing bacteria is largely removed from the suspension and added to the suspension at the beginning of the mass flow.

OMPI

4. The method according to claim 1, 2 or 3, characterized gekenn¬ characterized in that in each process stage, the gas obtained and collected in this is at least partially blown into the mass flow after heating in a plurality of jets in the region of several cross sections

5. The method according to claim 1, 2, 3 or 4, characterized ge indicates that in each stage of the process, the bacteria-containing, possibly heated, liquid drawn off in the area of a cross section of the mass flow is added to the mass flow in the area of at least one cross section lying in the direction of movement of the mass flow .

6. The method according to any one of claims 1 to 5, characterized in that the biogas obtained exclusively to a part for heating the or the gases or liquids to be circulated and the end product and optionally for drying and for the rest Part is used to generate the drive energy for the circulation pumps, mass transport pumps, drainage centrifuges and other machines.

Method according to one of claims 1 to 6, characterized in that the biomass contained in the suspension at the end of the second stage of the process is largely freed of liquid, briefly heated to a temperature of at least 70 ° C and then dried.

_, O PI

8. Device for performing the method according to one or more of claims 1 to 7, characterized by two trough-shaped, covered troughs (11, 12), the bottoms (15) of the loading end to the discharge end of a continuous gradient of at least approximately Have 2%.

9. The device according to claim 8, characterized in that the size ratio of the two troughs (11,12) is about 1: 1.5 to 1: 2.

10. The apparatus of claim 8 or 9, characterized gekennzeich¬ net that the bottoms (15) of the troughs (11,12) are divided into sections (A, B, C, ...), at the end of which there is a threshold (16), in the area of which removal devices (17) for liquid to be drawn off are arranged.

11. The device according to claim 8, 9 or 10, characterized gekenn¬ characterized in that in the trough walls (19) and in the bottom (15) pipes (20) with a plurality of against the interior of the troughs (11,12) directed nozzles ( 21) are arranged for the introduction of gas into the mass flow.

12. The device according to one or more of claims 8 to 11, characterized in that the inner walls (19) and bottoms (15) of the troughs (11, 12) are provided with a covering having a smooth hydrophobic surface.

13. The device according to one or more of claims 8 to 12, characterized in that the troughs (11, 12) consist of sections (A, B, C, ...) which are arranged one behind the other in a zigzag shape.

14. The device according to one or more of claims 8 to 13, characterized in that at the loading end of each trough (11, 12) at the level of the mass flow, an inoculation pot (32) or an inoculation channel (24) with an overflow for which the bacteria-containing vaccine fluid supplied is arranged.

15. The device according to one or more of claims 8 to 14, characterized in that the troughs (11, 12) are optionally arranged in a multiple arrangement under the floor of an operating hall, on or above which are necessary for the operation of the system Machines and pipes as well as apparatus and the like are located.