DE102006045872A1 - Biogas plant comprises parts having reactor chamber containing oil residue, which displaces with biological compound conveyed over piping and pumping devices in reactor chamber and is transformed through anaerobic reaction to methane-gas - Google Patents

Abstract

The biogas plant comprises parts having a reactor chamber (2) containing oil residue (3), which displaces with a biological compound (6) conveyed over a piping (4) and pumping devices (5) in the reactor chamber and is transformed through anaerobic reaction to methane-gas, which is conducted over a further piping (7) in a processing device. The reactor chamber is designed in subterraneous cavities such as capillaries, porous storages or caverns and is connected with above-ground mechanisms such as the pumping devices and/or the processing device over the pipings. The biogas plant comprises parts having a reactor chamber (2) containing oil residue (3), which displaces with a biological compound (6) conveyed over a piping (4) and pumping devices (5) in the reactor chamber and is transformed through anaerobic reaction to methane-gas, which is conducted over a further piping (7) in a processing device. The reactor chamber is designed in subterraneous cavities such as capillaries, porous storages or caverns and is connected with above-ground mechanisms such as the pumping devices and/or the processing device over the pipings. The parts are subterraneously arranged by the plant. The pipings in common earth boreholes are led by the reactor chamber at the surface of the earth. The above-ground processing device is realized by a cogeneration unit for heat- and power generation. A mixture of water sodium alginate is used as biological compound. An independent claim is included for a procedure for operating a biogas plant.

Description

The The present invention relates to a biogas plant in the at least the reactor space is deep in the ground and on a method of operating such a system.

biogas as a renewable energy source makes an environmentally friendly contribution to meet the energy demand. Its combustible methane is formed every anaerobic rotting process in swamps, Rice fields, landfills, digestion towers and in livestock farms. As starting materials for biogas production in biogas plants can in addition to feces and wastewater after appropriate pretreatment any form of organic waste used become. Corresponding municipal biowaste collection concepts have already been realized.

Biogas reactors more usual Design are above-ground containers within biogas plants, which are usually with manure and other biological substances discussed above.

From the DE 197 24 012 C2 is a complex biogas plant known, which in this document already the idea is expressed that parts of the biogas plant can be located underground (there, inter alia, claim 12).

The Formation of biogas is natural expiring process in which microorganisms are the organic substances without decomposing atmospheric oxygen into its basic building blocks. Digester gas or also called biogas, consists predominantly from methane and carbon dioxide and is flammable. In addition to different Reactor forms and building materials are in practice different systems for mixing and process control encountered.

The biogas or biogas is also produced outside of biogas plants, where its non-use represents a waste of energy resources. The escaping methane reacts in the course of time in the air to carbon dioxide and water, methane itself, however, before its natural oxidation in the atmosphere is a so-called greenhouse gas. Its technical use as a biogas produced fuel thus causes in contrast to fossil fuels in the overall energy balance no additional CO ₂ pollution of the atmosphere and thus no additional greenhouse effect. The recycling of digested sludge waste from biogas plants as natural fertilizer is an important contribution to the closure of ecological cycles between man, agriculture and the environment.

The Good manure stops at normal recycling (application on the fields) and in the event of possible overshoot of limit values is a real environmental problem. Where it is in surplus is present, a functioning logistics system must be set up which in turn causes other environmental burdens. The current focus of biogas production is therefore on agricultural Companies and municipal landfills and sewage treatment plants.

Also It is known that after the drying up of oil fields large quantities of low-grade residual petroleum in the extracted oil deposits. The utilization of these residual petroleum quantities is currently uneconomical and does not occur for that reason.

task The present invention is generally deep in the art Soil unused remaining petroleum residues to use, where the facility required to be relatively easy to create and both the procedure for their operation and the plant the environment as possible should affect little negative.

These Task is with a biogas plant with the characteristics of the claim 1 and with a method for operating such a biogas plant according to claim 6 solved.

On This way you will find a highly profitable, nearly complete exploitation the otherwise useless petroleum residues in the discharged deposits instead of.

Further Advantages result from the dependent claims.

Special Advantages of a biogas plant from the at least parts underground are then arranged, if the underground parts at least include the reactor space, and if this reactor space petroleum residues contains the one with over Pipelines and pumping facilities funded in the reactor room added to biological preparation and be converted by anaerobic reaction to methane gas, which over another Pipes is passed into a further processing device.

Of Furthermore, a biogas plant is advantageous if the reactor space in underground cavities like capillaries, pore reservoirs or caverns.

Furthermore, it is in a biogas plant according to the invention advantageous if the reactor space is connected to above-ground facilities such as pumping equipment and / or further processing facilities via pipelines, and if the above-ground processing equipment by a cogeneration plant for heat and Stromgewin realized.

Especially advantageous is a biogas plant, if the pipes to be filled with biological preparation and the piping for removing the methane gas by a common Drilled earth become.

at the biogas plant according to the invention is it especially cheap, if as a biological preparation a mixture of water and sodium alginate is used.

For operating a biogas plant, a process is advantageous which comprises the process steps:
Providing a fermentation-adapted biological preparation;
Introduction of the preparation into extracted oil deposits;
Supplying the preparation to the petroleum residues located, for example, in the caverns of the petroleum reservoirs;
Initiating the conversion of petroleum residues into methane (CH ₄ ) by microbiological processes such as fermentation;
Discharging the methane gas (CH ₄ ) to a further processing device.

at Such a method is advantageous when providing of the biological preparation u. a. includes mixing water with sodium alginate.

In addition, a method is advantageous in which the introduction of the biological preparation in the discharged oil deposits by means of pumping devices and pipelines, and in which the removal of the methane gas (CH ₄ ) also takes place by means of pipelines.

In the method according to the invention, it is particularly favorable that the conversion of the petroleum residues to methane gas (CH ₄ ) takes place through the use of the biological preparation while avoiding the formation of sulfur-hydrogen (H ₂ S).

With Help the drawing is based on a principle diagram of the invention even closer explained.

The FIG. 1 shows a schematic cross section through an underground biogas plant according to the invention.

In the soil 1 There is a cavern several thousand meters deep 2 , the inferior petroleum residues 3 from the final phase of oil production has. These petroleum remains 3 are no longer used because the processing of usable crude oil is economically too expensive. About pipelines 4 and pumping devices 5 becomes a biological preparation 6 in the form of a mixture of sodium alginate and water in the cavern 2 pumped. With the help of this biological preparation 6 , which is also a universal breeding ground for microorganisms, is produced by anaerobic digestion of the inferior oil residues 3 in the caverns 2 produced biologically methane (CH ₄ ).

This is due to the onset of anaerobic microbiology in the cavern 2 and / or in capillaries and in the mud of the caverns 2 the remaining petroleum residues 3 depending on the quantity of the preparation 6 very quickly converted into methane gas (CH ₄ ).

The methane gas CH ₄ is piped over 7 through the soil 1 led to the earth's surface. There it will be in an above-ground processing facility 8th further processed. Particularly suitable for further processing is a combined heat and power plant for heat and power generation. The generated heat can be supplied as process heat to the conversion process, if necessary or advantageous. The heat can also be used elsewhere. The electricity generated can be fed into the public grid or otherwise used.

It is advantageous if the discharge of methane gas CH ₄ through pipes 7 takes place in the immediate vicinity of the pipelines 4 are laid through which the biological preparation 6 in the underground reactor room 2 is initiated. Although this is not mandatory for a realization, but very beneficial, because then only a costly hole is to be made. This variant is represented by a dashed line 7 shown in the figure.

Also possible realization in which the pipeline 7 spatially from the pipeline 4 separated by the soil 1 is guided in the figure by a drawn with solid lines pipe 7 shown.

It is understood that the pumping devices 5 spatially with the finishing device 8th - For example, in a building - can be summarized. This does not have to be shown in the drawing.

The mixing ratio of the biological preparation 6 and the over pipelines 4 and pumping devices 5 into the cavern 2 initiated amount of the biological preparation 6 depends on the amount of remaining petroleum residue 3 and the geological properties of the caverns 2 or the capillaries in which are the petroleum residues 3 can also be located. Also in pore stores can There are petroleum residues that can be converted in accordance with the invention. These variants are difficult to represent graphically, but are included in the invention idea.

The most often required in conventional biogas plants stirrers can be omitted without replacement, as by the underground fermentation process sufficient mixing of the reacted organic matter, namely petroleum 3 , he follows.

Today's focus of biogas production is on farms and municipal landfills and wastewater treatment plants. The use succeeds, however, regrettably still very limited. In particular, in landfills and sewage treatment plants, the biogas obtained is often simply flared or used at most for heating. Another and better use of the biogas can be done only after its purification, because the biogas impurities, such as toxic and foul smelling sulfur-hydrogen and other are included. Sulfur-hydrogen is a colorless gas that causes negative effects on humans and the environment as well as on the operation of biogas plants. H ₂ S is highly toxic to humans. It attacks the mucous membranes of the eyes and the respiratory tract and is lethal at a higher concentration in no time. In the operation of biogas plants, especially its strong corrosive effect has a negative effect. The sulfur-hydrogen prevents, for example, the use in enclosed spaces as well as in conventional internal combustion engines, where biogas in principle serves to generate electrical energy and heat. When used in such internal combustion engines, it oxidizes to toxic SO ₂ and corrosive sulfuric acid. This affects all parts of the biogas plant that come into contact with the H ₂ S. This applies especially to combined heat and power plants (CHPs), where the biogas is burned, generating electricity and heat. During combustion, SO ₂ is also produced here, which leads to acidification of the engine oils and thus to a drastic shortening of the oil change intervals. But other fittings in the CHP, which come into contact with the biogas, are affected. The result is often a significant reduction of the system lifetime, meaning its life is meant. In addition, the calorific value is lowered by the natural CO ₂ content, which is between 20 and 40% by volume, depending on the plant.

The biological preparation 6 From water and, for example, sodium alginate already has excellent properties in preventing the formation of sulfur-hydrogen (H ₂ S), so that in this regard, the recovered methane gas (CH ₄ ) has favorable properties and eliminates the disadvantages described above.

In summary, the present invention relates to a biogas plant in which at least the reactor space is located deep in the ground, namely in the caverns of extracted oil fields. In this reactor room still poor quality petroleum residues are contained, which are mixed with biological preparations such as sodium alginate and converted by anaerobic fermentation to methane gas (CH ₄ ).

On This way you will find a highly profitable, nearly complete exploitation the otherwise useless petroleum residues in the discharged deposits instead of.

1

soil

2

cavern

3

Petroleum residue

4

pipeline

5

pumping device

6

biological preparation

7

pipeline

8th

Further processing device

Claims (12)

Biogas plant of which at least parts are arranged underground, characterized in that the subterranean parts at least the reactor space ( 2 ), and that this reactor space ( 2 ) Petroleum residues ( 3 ), which is connected to a pipeline ( 4 ) and pumping devices ( 5 ) into the reactor space ( 2 ) promoted biological preparation ( 6 ) and converted by anaerobic reaction to methane gas (CH ₄ ), which via further pipelines ( 7 ) in a further processing device ( 8th ). Biogas plant according to claim 1, characterized in that the reactor space ( 2 ) is placed in underground cavities such as capillaries, pore reservoirs or caverns. Biogas plant according to claim 1, characterized in that the reactor space ( 2 ) with above-ground facilities such as pumping devices ( 5 ) and / or further processing devices ( 8th ) via pipelines ( 4 . 7 ) connected is. Biogas plant according to claim 1, characterized in that the pipelines ( 4 . 7 ) in spatially separated earth bores from the reactor space ( 2 ) are led to the earth's surface. Biogas plant according to claim 1, characterized in that the pipelines ( 4 . 7 ) in a common well bore from the reactor space ( 2 ) at the earth's surface are led. Biogas plant according to one of the preceding claims, characterized in that the above-ground further processing device ( 8th ) is realized by a combined heat and power plant for heat and power generation. Biogas plant according to one of the preceding claims, characterized characterized in that as a biological preparation, a mixture of water and sodium alginate finds application. Method for operating a biogas plant, characterized by the method steps: provision of a biologic preparation suitable for fermentation ( 6 ); Introduction of the preparation ( 6 ) in extracted oil deposits; Feeding the preparation ( 6 ) to, for example, the caverns ( 2 ) of petroleum residues ( 3 ); Initiate the conversion of petroleum residues ( 3 ) in methane (CH ₄ ) by microbiological processes such as fermentation; Discharging the methane gas (CH ₄ ) to a further processing device ( 8th ). Method according to claim 6, characterized in that the provision of the biological preparation ( 6 ) including mixing of water with sodium alginate. A method according to claim 6, characterized in that the introduction of the biological preparation ( 6 ) into the extracted oil deposits ( 2 ) by means of pumping devices ( 5 ) and pipelines ( 4 ) he follows. A method according to claim 6, characterized in that the discharge of the methane gas (CH ₄ ) by means of pipelines ( 7 ) he follows. A method according to claim 6, characterized in that by the use of the biological preparation ( 6 ) the conversion of petroleum residues ( 3 ) to methane gas (CH ₄ ) while avoiding the formation of sulfur-hydrogen (H ₂ S) takes place.