DE102010010420A1 - Operating a biogas plant with a fermented, in which or into which preconditioned fermentation pulp from biomasses is introduced and biogas is removable from collection volume, comprises conditioning biomass to flow able fermentation pulp - Google Patents

Abstract

The method for operating biogas plant with a fermented (1), in which or into which a preconditioned fermentation pulp from biomasses is introduced and biogas is removable from a collection volume, comprises conditioning the biomass to a flow able fermentation pulp and then introducing into a tube or tubular system, which automatically forms the fermentation chamber, where the biomass is present between an inlet zone (2) and a discharge zone (3) of the tube or the tubular system, and influencing the flow velocity in the tubular system. The method for operating biogas plant with a fermented (1), in which or into which a preconditioned fermentation pulp from biomasses is introduced and biogas is removable from a collection volume, comprises conditioning the biomass to a flow able fermentation pulp and then introducing into a tube or tubular system, which automatically forms the fermentation chamber, where the biomass is present between an inlet zone (2) and a discharge zone (3) of the tube or the tubular system, and influencing the flow velocity in the tubular system, so that a dwell time of the biogas of the produced fermentation pulp is controllable in the tubular system. The gas production rate is steadily measured and the control of the dwell time of the biomass or the fermentation pulp takes place in the tubular system dependent of the gas production rate. The tubular system is provided with distributed arranged semi-permeable membranes (7), which guide through the biogas but blocks the passage of the liquid, over which the produced biogas discharges from the tubular system. The liquefied animal rumen or other microbial additives and/or trace elements and/or minerals are introduced into a tubular fermented at an inlet opening or at the distributed arranged injection openings along a tube length. The biogas plant or the tubular fermented is integrated into a coolant circuit of a thermal power plant in a heat-exchanging manner, so that the power plant waste heat is added for supporting the biogas production process. An independent claim is included for a biogas reactor or a biogas plant with a fermented.

Description

Method for operating a biogas plant with a fermenter, in which or in which a preconditioned Gärbrei from biomass can be introduced, and biogas from a collecting volume is deductible, in particular for the use of aquatic biomass, and biogas plant itself, according to the preamble of claims 1 and 7.

Biogas plants contain fermenters, which are a fluid-tight system connected on all sides. All elements of the system including the biomass are removed only in a controlled manner. Inside the plant, a volume of space is created into which the biogas can expand.

Such devices with roof-shaped cover are widely known; so for example from the DE 10 2007 057 118 A1 ,

In large biogas plants, it is also necessary to stir the Gärbrei the biomass at regular intervals in order to keep the biological, or better the microbial activity throughout the Gärbrei as uniform as possible. Ultimately, an optimal biogas yield from the registered biomass is the goal.

The residence times of the biomass in the fermentation chamber are of decisive importance for the profitability of biogas plants.

Equally important is any energy input that can be fed into the system, because it reduces the ecological efficiency of producing an energy source from renewable raw materials.

Of particular importance is the use of biomass from aquatic plants. Their difference between drained weight and dry matter is significantly higher than other plants. In this respect, the significantly higher moisture content of such biomass plays a role in the entry into biogas plants or in the fermenter of biogas plants.

The invention is therefore based on the object to make a method of the generic type, in particular for the use of biomass from aquatic plants more economical, and to be able to dispense with motor stirrers.

The stated object is achieved in a method for operating a biogas plant of the generic type according to the invention by the characterizing features of claim 1.

Further advantageous embodiments of the method are specified in the dependent claims 2 to 6.

With regard to a biogas plant itself, the stated object is achieved by the characterizing features of claim 7.

Further advantageous embodiments are specified in the remaining dependent claims.

The core of the process according to the invention is that the biomass is conditioned to a flowable Gärbrei and in a pipe or pipe system, which is the fermentation space itself, is passed and between the inlet region and outlet region of the pipe or pipe system is a gradient, and that influences the flow rate in the pipe system so is that the residence time of the biogas generating Gärbreies is controllable in the pipe system in this way.

The essential difference to known biogas plants is thus the arrangement of the fermentation space as a pipe, or Rohrmäander with continuous slope.

The Gärbrei can move in this way even with respect to its respective consistency, liquid or toughened, exactly dependent on it at different speeds. For the slow flow of the fermenter ensures the greatest part of the slope. Thus, neither energy for the application of Gärbreies still for his "stirring" be spent. If the Gärbrei is even tougher, and therefore more so, its throughput speed through the tube is slower. If at the end of the gas process, the Gärbrei is always liquid, it flows faster towards the exit. Thus, the length of stay on the slope already partly regulated itself.

On the other hand, the locally generated gas pressure can also support a pressure-gradient-related movement of the fermentation mixture.

In a further advantageous embodiment, it is indicated that the gas generation rate is measured continuously, and depending on the control of the residence time of the biomass or the Gärbreies takes place in the pipe system. As already stated above, this can be achieved by utilizing the gas pressure generated by the biogas itself. This can be done by measuring the pressure in different places distributed in the pipe. Further, exhaust valves for discharging the biogas may be arranged along the pipe or the pipe section. If now a Gärbreivolumen guest in a first pipe section, it can be created by a foreclosure of the underlying Rohrbreiches and opening a valve in front of the pipe section a pressure gradient the biomass moves automatically in the direction of lower pressure.

In a further advantageous embodiment, it is stated that the pipe system is provided with distributed semi-permeable (semipermeable) membranes, which pass through (bio) gas but block the passage of liquid through which the biogas produced emerges from the pipe system. Thus, the biogas produced in the tube fermenter escapes from the same and collects in a space above it.

In a further advantageous embodiment it is stated that liquefied animal rumen or other microbial additives and / or trace elements and / or minerals are introduced into the tube fermenter at the inlet opening or along the tube length at distributed injection openings. These support the gas process enormously. As a rule, in known biogas plants, fermenting additives are added right at the beginning. In the method according to the invention, however, these can be injected along the travel path, whereby a continuously good gas process is obtained.

In a further advantageous embodiment, it is indicated that the biogas plant or at least the tube fermenter is incorporated into the coolant circuit of a power plant heat exchanging, such that the power plant waste heat is added to support the biogas production process. In this case, the Rohrfermenter, or the water basin, in which it is created to use the waste heat from power plant coolant circuits. This heat, otherwise unused to the environment, has significant utility in sustaining an efficient biogas production process in this form of use.

With respect to a biogas plant, the essence of the invention is that the biogas reactor or the biogas plant comprises a fermenter consisting of a pipe or a pipe system, which is inclined between the inlet region and outlet region or at least partially, in which the flowable Gärbrei is introduced. At least partially inclined, means that in the arrangement of the pipe system as meander a steady inclination is present at least along one axis. This is made clearer by the description of the drawing below.

This means that advantageously the pipe or pipe system is laid meandering, and the slope is chosen so that the Gärbrei flows steadily slowly and largely by gravity through the pipe system.

Conkretermaßen a design is provided in which the pipe or pipe system is provided with one or more Biogasablassanschlüssen, which in turn is provided with one or with a respective semipermeable membrane over which escape biogas, but no liquid can pass through. This is a suitable discrete distribution of biogas exit points. Due to the discrete distribution of such Biogasablassanschlüsse along the pipe system, it can cause a pressure build up in the pipe sections between such biogas outflows. This supports, so to speak, self-motor flow or pressure-related pushing through the Gärbreies with time. In this way, it requires no pumping of the pipe system from the outside.

In a further advantageous embodiment it is provided that the pipe or pipe system is provided with the flow rate controlled influencing adjustable flow bodies, via which the optimum residence time of Gärbreies and / or the turbulence in the fermenter is controllable. In conventional fermenters agitators are provided for the Gärbrei, which are operated discontinuously. In the fermenter according to the invention such agitators are completely obsolete not only because of the introduced flow body.

In a further advantageous embodiment, it is specified that biogas flow meters are provided, via which the amount of biogas discharged can be determined, and the flow bodies can be adjusted via a control device so that optimum residence times can be controlled.

Furthermore, it is of particular advantage that the tubular or tubular meander-shaped fermenter can be arranged in a liquid or water basin, such that the biogas bubbles through the liquid (water) and passes under a hood arranged above the liquid or water level (foil). collects for final biogas deduction. The outflow of biogas through water has several functional advantages. On the one hand, the biogas is purified as such. On the other hand, a partial solution of the carbon dioxide contained in the biogas in the water. The level of carbon dioxide in solution can be increased by increasing the pressure. In this way, the finally emanating from the water surface biogas is already present with a higher methane content than the exiting the fermenter biogas.

In a further advantageous embodiment, it is stated that the water polluted by the biogas can be cleaned (improved) by a fresh water feed, and the wastewater withdrawn therefrom as a fertilizing solution for crops, especially aquatic crops is available. This means that not only the "washed-out" components (long-chain hydrocarbon compounds, etc.) but also the CO ₂ dissolved in the water are used as fertilizer. The sometimes considerably growth-promoting property of an increased supply of carbon dioxide, thus also promotes the biomass yield of the fertilized thereby plants.

In the last, but considerably advantageous embodiment is stated that the said crops or aquatic plant crops are created in a closed biomass reactor (greenhouse), and with said biogas reactor form a closed recycle cycle for water, biomass and CO ₂ , or the biogas reactor in the Biomass reactor is integrated.

In the latter case, the biogas reactor is integrated into the biomass reactor, but the biogas does not run out into the biomass reactor, but is separated from it separately. Probably the CO ₂ and the water together with filtered-off components is recycled into the cultivated areas of the biomass reactor.

In the former case, the biogas reactor can also be placed directly in the biomass reactor.

In a further advantageous embodiment, it is stated that the biogas reactor is provided or connected with a microbial fuel cell in such a way that the contaminated water is conducted over it, in which bacteria are settled on the electrodes, which carry out a galvanic charge separation via biochemical processes. Such microbial fuel cells are already known per se. Their integration into a biogas reactor or into a biomass reactor according to the invention is of considerable advantage because the energy thus obtained can readily be used again for the illumination of the aquatic plant cultures. In this way, a nearly Fremdergie self-sufficient system for the production of energy sources in the closed material and CO ₂ cycles achieve a significant increase in efficiency.

In a further advantageous embodiment, it is therefore stated that illuminants for illuminating the aquatic cultures in the biomass reactor can be operated via the electrical energy generated by the microbial fuel cell. Consequently, light-emitting diodes are used as the light source, the energy requirement of which, due to a significantly higher degree of efficiency, is correspondingly small.

The invention is illustrated in the drawing and explained in more detail below.

It shows:

1 : Fermenter of the biogas plant as a meander

2 : Rohrmäander in Wasserbassin

3 : Partial cut pipe socket with semipermeable membrane

4 : Overview of the material cycles

1 shows the fermenter according to the invention 1 the biogas plant as Rohrmäander. 1 shows in the upper part of a side view and in the lower part of a plan view. In the entry area, the feeding of the Gärbreies takes place, in which substantially aquatic plants, eg Lemna (duckweed) and / or Azolla is included, which are used in the biomass reactor not shown here. In the illustrated plan view, short pipe sections result 4 and perpendicular long pipe sections 5 , For example, in the short pipe section are each pipe socket 6 arranged by a valve and / or a semipermeable membrane 7 are covered. From these emerges the resulting biogas.

Between the entrance opening 2 and the exit opening 3 there is a gradient, so that under the influence of the G-vector of Gärbrei slowly, but especially automatically by the fermenter or better said the Rohrfermenter 1 passes through.

The result is a constant volume throughput of Gärbreies. Along the slow movement of the Gärbreies through the Rohrfermenter the Gärbrei then guest out his biogas.

Due to the distributed arrangement of pipe sockets 6 to the gas outlet create distances within the Rohrfermenters 1 This can be supported by an alternating opening of valves on the various pipe sockets so that pressure gradients arise in the pipe sections that propel the Gärbrei with.

The gradient between the inlet 2 and outlet 3 is created along the major axis x. But it can also be a kind of stepped slope along the main axis x and also applied perpendicular thereto. Finally, the important factor is the resulting gradient between the inlet opening 2 and outlet 3 ,

Such tube fermenters 1 can even be buried over a large area in a field on which then the cultivation of biomass harvested there takes place. The biogas drains are then connected in such a case with a biogas extraction system.

Another application example shows 2 , This is the provided with gradient Rohrfermenter 1 in a water basin 8th admitted. These are the gas outlets 6 with a semipermeable membrane 7 Mistake. This allows biogas through, but blocks the entry or exit of liquid. Due to the gradient in the tube fermenter 1 , shown here in a stepped manner, arises above each respective pipe socket 6 another hydrostatic pressure, because every pipe socket 6 another distance to the water level 9 Has.

The effluent biogas bubbles through the water and then collects above the water level 9 in a gas volume, which in turn with a gas outlet 11 , For example, an openable and closable valve is provided. Biogas consists of a part (50% to 60%) of methane, the actual energetic recyclable material, and the remainder mainly of carbon dioxide (CO ₂ ).

Biogas is subsequently methanized in many cases. For this purpose, the CO _{2 is} removed by known methods.

In the present case, the pressure conditions in the gas volume together with the hydrostatic pressure are effectively designed so that there is an increased solution of CO ₂ in water as soon as the biogas passes through the water.

In other words, this means that in the biogas plant according to the invention already takes place for a first methanation on at least about 70% and more methane content.

Furthermore, other impurities such as long-chain (tarry) hydrocarbons are dissolved in water. This also applies to other substances that are actually undesirable in the gas.

This is followed by an equally well use chain according to the invention. First, as stated above, a light premethanization precursor. On the other hand falls to "dirty" water, in which both carbon dioxide to bicarbonate, as well as other organic impurities are solved.

Now, this water is recycled as quasi-fertilizer (CO2 and concomitant) laden water to the cultures of biomass plants, here essentially aquatic plants. From Lemnacea (duckweed), the significant growth-promoting effect of CO ₂ etc is known. A recycling of exactly this water of a biogas plant according to the invention in such a biomass reactor causes a boost of biomass production capacity. In addition, more biomass, resulting in more gas etc.

For additional generation of electrical energy also required in the system, the dirt-polluted water of the water basin, which is drawn off from time to time by flushing, is passed through a so-called microbial fuel cell. There, the electrodes are colonized with microbes. Their property of filtering off certain ingredients leads to a galvanic effect on the electrodes, which leads to an electrical charge separation. This is removable as an electric current. However, this current thus generated, even at low power density can be used at least for the light-emitting diodes for further growth stimulation of aquatic plants in the biomass reactor.

The overall efficiency also increases steadily.

Important is the logistic material and CO2 cycle between biogas plant and biomass reactor, in the described way.

This biogas plant can be integrated into a large greenhouse (biomass reactor) for aquatic crops.

But at least the biogas plant and the biomass reactor should be placed adjacent to realize short logistical ways.

3 shows a basic detail of 2 in which the pipe section 4 with the pipe socket 6 for biogas discharge is shown. Inside the pipe section 4 of the fermenter is a gas pressure P1 before. The pipe socket 6 is with a resilient semi-permeable membrane 7 locked. To consider are compared to the internal pressure P1, which is generated by the upcoming biogas, the distance between the membrane 7 and water level 9 , Due to the hydrostatic pressure and the pressure above the water level 9 in the collecting space of the biogas, a pressure P2 is jointly formed.

Now the following functional conditions apply.

The pressure P1 must be greater than P2, so that at all biogas exits the Rohrfermenter and bubbles in the desired manner through the water.

In the gas production arise on the order of pressures (against atmosphere) of less than or equal to 1 bar. If necessary, more. But this is sufficient to represent a water basin depth of less than or equal to one meter.

In this way, gradients of the Rohrfermenters of 3 to 4% can be realized at a length of 30 meters. The width can be good 10 to 20 meters. Thus, in this example, the meanders can be used to gain an effective total length of 900 mtr.

By using pipe diameters of 40 cm in the tube fermenter, effective fermentation spaces of more than 100 cubic meters can be created. However, the advantage is not in the largest possible fermentation volume, but in a constant material throughput.

In many biogas processes, 2/3 of the available biogas is already generated within the first 7 days. Based on this for the throughput of the biogas plant according to the invention, this means a slow feed rate of 128 meters per day, or 5.3 meters per hour.

The big advantage is the steady throughput. The Gärbrei removable at the outlet opening can then be passed to the post-fermentation of the remaining 1/3 biogas in a Nachvergärer, which is designed to be larger in volume than the tubular or meandering fermenter.

The above-mentioned extraction pressure P2 in the gas collection volume can be achieved via the valve on the gas outlet 11 Adjust so that it affects the pressure P1 in the fermenter with. So you can even control the feed rate of Gärbreies in the fermenter on the control of the withdrawal pressure P2, ie regulate.

For static reinforcement of the water basin, this can be sunk into a soil excavation so far, so that protrudes only the upper gas collection volume. This also leads to a virtually seasonal independent operating temperature of the fermenter, because this rests in a Wasserbassin, which in turn is thermally well shielded by the depression in the ground.

The entire Rohrfermenter can be provided along its length with sensory interfaces or sensors through which the parameters of the Gaspozesses can be determined, such. b. the pH value, temperature, etc. By means of said injection orifices, the gas process can then be controlled or increased by adding microbes or shredded animal rumen, or minerals and trace elements.

4 shows an overview of the material cycles. Thus, in the Rohrfermenter injection openings 12 provided through which along the passage of the Gärbreies through the Rohrfermenter microbes, or crushed animal pests and / or minerals and / or trace elements are injected. These promote the biogas process considerably.

In the biomass reactor 13 In aquatic cultures aquatic plants are propagated, for example Lemnacea, which are extremely fast-growing (doubling every 1 to 3 days). It falls steadily, ie daily biomass, taken from the biomass reactor and a Gärbreiaufbereitung or preparation 14 is supplied. There, at least part of the moisture of the biomass is withdrawn, and then crushed and already premixed with certain food-borne substances. This conditioned Gärbrei is from there the entry area 2 fed to the Rohrfermenters, where the biogas production ie the fermentation begins.

At the outlet of the Rohrfermenters the outgassed Gärbrei is removed and either fed to a post-fermentation or the digestate directly via a water mixture 15 led, the thus obtained fertilizer solution is returned to the biomass reactor. The water also contains dissolved carbon dioxide. Everything together exerts a tremendous growth-promoting effect on the aquatic plant cultures.

One way of operation is also to use the meander meander as a floating facility on water surfaces with aquatic cultures in the field. This results in similar material cycles. Only the biogas outlet through the nozzle is done so that the nozzles are connected to pipelines.

LIST OF REFERENCE NUMBERS

1

Pipe meander, fermenter

2

entry area

3

exit area

4

Short pipe sections

5

Long pipe section

6

Gas outlets / pipe stub

7

Semipermeable membrane

8th

water basin

9

water level

10

gas volume

11

gas vent

12

injection port

13

biomass reactor

14

Gärbreivorbereitung

15

Wasseraufmischung

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 patent literature

• DE 102007057118 A1 [0003]

Claims (15)

A method for operating a biogas plant with a fermenter, in which or in which a preconditioned Gärbrei from biomass can be introduced, and biogas from a collecting volume is deductible, characterized in that the biomass conditioned to a flowable Gärbrei and in a pipe or pipe system which the Fermentation itself forms, is directed and there is a gap between the inlet and outlet of the pipe or pipe system, and that the flow rate in the pipe system is influenced so that the residence time of biogas generating Gärbreies is controllable in the pipe system in this way. A method according to claim 1, characterized in that the gas generation rate is measured continuously, and depending on the control of the residence time of the biomass or the Gärbreies takes place in the pipe system. A method according to claim 1, characterized in that the pipe system is provided with distributed semi-permeable (semipermeable) membranes which pass through (bio) gas but block the passage of liquid over which the generated biogas exits the pipe system. Method according to claim 1, characterized in that liquefied animal rumen or other microbial additives and / or trace elements and / or minerals are introduced into the tube fermenter at the inlet opening or along the tube length at distributed injection ports. A method according to claim 1, characterized in that the biogas plant or at least the Rohrfermnenter is integrated heat-exchanging into the coolant circuit of a power plant, such that the power plant waste heat is added to support the biogas production process. Biogas plant with a fermenter, in which or in which a preconditioned Gärbrei from biomass can be introduced, and biogas from a collecting volume is deductible, characterized in that the biogas reactor or the biogas plant, a fermenter ( 1 ), which consists of a pipe or a pipe system which between inlet region ( 2 ) and exit area ( 3 ) or at least partially inclined, in which the flowable Gärbrei is introduced. Biogas reactor or biogas plant with fermenter, characterized in that the pipe ( 1 ) or pipe system is laid meandering, and the slope is chosen so that the Gärbrei flows steadily slowly and largely by gravity through the pipe system. Biogas reactor or biogas plant with fermenter, characterized in that the pipe ( 1 ) or piping system with one or more biogas discharge connections ( 6 ), which in turn is provided with one or each of a semipermeable membrane ( 7 ) is provided, over which biogas leak, but no liquid can pass through. Biogas reactor or biogas plant with fermenter, characterized in that the pipe ( 1 ) or pipe system with the flow rate controlled influencing adjustable flow bodies is provided, via which the optimum residence time of the Gärbreies and / or the turbulence in the fermenter is controllable. Biogas reactor or biogas plant with fermenter, characterized in that a biogas flow meter are provided, via which the amount of biogas discharged can be determined, and via a control device, the flow body are adjustable so that optimum residence times are controllable. Biogas reactor or biogas plant with fermenter, characterized in that the tubular or rohrmäanderförmige fermenter ( 1 ) in a liquid or water basin ( 8th ) in such a way that the biogas bubbles through the liquid (water) and flows under one above the liquid or water level ( 9 ) arranged hood (foil) collects the final biogas fume. Biogas reactor or biogas plant with fermenter, characterized in that the biogas contaminated water can be cleaned (improved) by a fresh water supply, and the wastewater withdrawn therefrom as a fertilizer solution for crops, especially aquatic crops is available. Biogas reactor according to claim 12, characterized in that the said crops or aquatic plant crops in a closed biomass reactor ( 13 ) (Greenhouse) are created, and with the said biogas reactor form a closed recycle cycle for water, biomass and CO ₂ , or the biogas reactor in the biomass reactor ( 13 ) is integrated. Biogas reactor according to claim 12 or 13, characterized in that the biogas reactor is provided or connected with a microbial fuel cell, so that the contaminated water is passed over this, in which the electrodes are located on the bacteria over biochemical processes make a galvanic charge separation. Biogas reactor according to claim 12 or 13, characterized in that on the electric power generated by the microbial fuel cell lighting means for illuminating the aquatic cultures in the biomass reactor are operable.

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