This invention relates to a portable / prefabricated biogas plant. Normally all biogas plants works with the profuse use of cow dung. But this biogas plant is working without the regular use of cow dung. In a biogas plant, the biomass is digested in a digester and biogas produced is stored in gas collector and is used as required. This biogas plant is light weight & easy to handle. It required minimum space to install and can use all the household waste materials for generating bio energy / biogas.

PRIOR ART

The disposal of waste or management of waste is one of the most critical issues the people all over the world face today. They are in search of appropriate technology for hygienic waste disposal. The main reason for origin and spread of epidemics is over pollution due to careless and negligent disposal of organic waste. The dumping of such decaying waste in open stage form spread unpleasant odor and such waste is attracted by the mosquitoes, flies, rates and other insects, who are the carriers of dangerous diseases.
Poisonous gas emissions from waste materials lead to environmental problems including global warming and climatic change and depletion of Ozone layer. Rural people normally depend upon biomass fuels, such as fire wood, animal waste and crop residues for meeting cooking and heating energy requirements. These fuels are burnt in an in-efficient manner in traditional forms, causing not only economic loss to the nation but also health problems to women.

The excess use of Liquefied Petroleum Gas (LPG), Petroleum products, and Electricity leads to more pollution in the atmosphere and huge economic burden. Now we are in force to use atomic energy for our day to day energy needs.

The present level of consumption of firewood and Petroleum products is considered unsustainable; the burning of animal waste and agricultural residues deprive our soils of much needed organic matter, and will adversely affecting soil health and agricultural productivity. Fortunately, technologies have been developed indigenously to produce modern biomass fuel, such as biogas from cattle dung and other organic wastes and to burn biomass in an efficient manner.

The generation of gobar gas / biogas from cow dung is a technology accepted universally. The anaerobic bacteria will be growing in multiple in the cow dung quickly. Any bio-degradable waste material can be mixed with cow dung and can be fed into the biogas plant for generating bio energy / biogas for cooking purposes domestically.

Alternative for decomposing the bio-degradable materials anaerobically without adding cow dung and for generating biogas from it, special type of bacteria will be cultivated in the laboratory separately and has to be mixed with waste. This process is more expensive and so it is not affordable by a common man.

Due to the scarcity and reduction of the availability of petroleum products gives an indication about the finding out of other fuel to the daily use of human beings. The present invention of portable / prefabricated biogas plant plays an important role in the use and process of renewable source of energy. Every household can produce biogas / bio energy through the waste materials produced in the household. There is no regular use of cow dung or any other cultural bacteria for the operation of the said plant.

The use of biogas / bio energy reduces emission than while using the fossil fuels and we get a pollution / odor free healthy atmosphere. Conventional and other model biogas plants take more space for the installation. The intended plant can create a revolution in the field of domestic waste treatment. The major outputs from the portable prefabricated plants are (1) Biogas / Bio Energy and (2) Organic manure.

The Biogas Plant serves many purposes such as:
√ Environment friendly disposal of bio degradable organic waste materials / household waste materials.

√. Generation of fairly good amount of fuel / biogas / bio energy, which will definitely support as energy resources.

√. Biogas is a colourless, odorless and inflammable gas. The gas generated can also be used as a source of renewable energy.

√. Biogas Plant totally eradicates the Smoke at the time of cooking.

√. The portable / prefabricated Biogas plant is operated with the help of household waste materials.

√. The Biogas plant is light weight and easy to install with minimum space.

√. Design of the plant is according to the available space and waste materials.

The biogas plant normally consists of two components, a digester and a gas collector / gas holder. The digester could be a cube-shaped or cylindrical waterproof container with an inlet into which the fermentable mixture is introduced. The gas collector is normally an airproof container, by floating in the fermentation mix, cuts off air to the digester and collects the gas generated. The gas holder is equipped with a gas outlet, while the digester is provided with an overflow pipe to lead the treated slurry out into a collection pit.

FIELD OF THE INVENTION

The present invention is an improved / modified version of invention claimed in application No. 2454/che/2007 and the respective grant Patent No. 243023 by the same inventor. The inventions are related to a portable / prefabricated biogas plant for treating household waste materials for generating bio energy / biogas. This biogas plant is light weight & easy to handle and required minimum space to install. This invention helps to improve the efficiency of the plant.

BACKGROUND OF THE INVENTION

The present invention discloses a portable domestic biogas plant comprising a 'digester' provided at the lower portion with feed and discharge facility, a gas collector provided at the top portion of the said plant, making the gas generated in the said digester to flow upwards and to be collected in it, the said gas collector being movably placed over the said digester and also fixed in the middle of the said digester with the help of guide frames; the said gas collector being provided with gas flow control means to regulate the supply of gas flow for consumption.

The digester is provided with feed and discharge facility, wherein an inlet pipe is provided for feeding the waste matter into the digester and an outlet pipe is provided at the top side of the digester for the digested slurry to come out. The gas collector is fixed in a center guide frame provided in the middle of the digester. The center guide frame is fixed in the middle of the digester with three lugs. These lugs and center guide frame are made of galvanized iron. The center guide frame is covered with fiber glass reinforced plastic to protect the same from rust. These lugs can be increased according to the size / capacity of the digester. The flow control means provided in the gas holder is the flow control valve to regulate the supply of gas which is stored in the gas collector.

ACTIVATION OF THE PLANT

Initially the digester of the plant is filled with processed cow dung (BIOTECH culture) with equal quantity of water. Slowly bio - methanization process takes place and biogas starts generating from slurry (i.e., mixture of water and cow dung). Within 2 to 3 days, the plant will start working with good performance due to the maximum growth of anaerobic bacterial (microbes) in the digester.

After the 4th day 10 to 20 liters of organic waste water collected from the kitchen (fish and meat cleaning water, rice cleaning water etc..) is added tot the plant through the inlet chamber of the plant.

Next day 20 to 30 liters of organic waste water can be fed. On the 6th day the same quantity of water with 1 to 2 kg of solid cooked food waste can also be mixed with the waste water and the same can be fed into the plant. Slowly the solid content in the waste water can be increased. Through this systematic process the microbes in the digester is becoming capable to decompose and all type of biodegradable waste and to generate biogas from the bio waste without adding cow dung. There is no need to add cow dung for further operation of the plant.

If this process is not followed properly, the plant will not generate biogas properly and the generated gas will not be capable to burn and if more quality of bio waste is fed into the plant, the biogas may not be generated by the plant due to the acidity formation in the digester. In that case foul smell also generate from the plant. So care must be taken to avoid the formation of acidity in the plant.

For treating the solid waste accumulated from a family of 3 to 5 members, a one cubic meter capacity plant would be sufficient. The gas generated from the plant is sufficient to replace 50% to 60% of the consumption of LPG every day.

The size of the plant will depend upon the quantity of waste. For constructing a biogas plant by traditional way using construction materials like bricks, cement mortar or concrete, minimum 5 to 7 days are required to complete the construction of the plant.

By using the Fiber glass reinforce plastic (FRP) as a construction material, the weight of the plant and the construction time of the plant can be considerably reduced. If there is no sufficient space to dig a pit and to construct a plant on the ground, the plant can be put on the terraces or any other convenient place.

Through the installation of a portable biogas plant we can dispose the organic wastes generated in the house and get bio energy for our daily needs. Now we are facing the scarcity in the availability of LPG.

DAILY OPERATION OF THE PLANT

Bio waste and organic waste water from the kitchen is collected in a bucket or bin and is fed into the plant through the inlet chamber of the plant. The waste goes to the digester through the inlet pipe. The waste treatment biogas generation process take place inside the digester cultivated and filled with anaerobic bacteria. The digester is an air-tight chamber constructed by the Fiber Glass Reinforced Plastic (FRP). The microbes in the digester react with the waste and convert into biogas and bio manure. Biogas is a mixture of Methane and Carbon dioxide and other gases in traces quantity. The gas generated from the waste is collected in the gas collector. The gas collector is made of Fiber Glass Reinforced Plastic (FRP) and fixed in a center guide frame fixed in the middle of the digester. To centralize the gas collector in the digester and for proper movement of the gas collector, it is fixed in a centre guide frame.

During feeding, the waste is going to the bottom of the plant and treated waste/slurry is coming out from the plant through the outlet pipe of the plant fixed on the top side of the digester. Once gas is generated, it is stored in the gas collector. Then the gas collector lifts up slowly to the top level of the slurry (waste) in the digester. Once the gas collector is filled and if it is not used in time, then the excess gas is liberated into the atmosphere from the sides of the collector automatically. There is a provision in the digester to rest the gas collector in the digester called Cornish, fixed above the three lugs supporters of the centre guide frame. The weight system inserted in the top of the gas collector, i.e., upon the centre guide frame will help to equal distribution of pressure in the gas collector.

The instant application for patent is an improved / modified version of the specifications claimed by the same inventor with patent grant No. 243023. The present invention helps to improve the efficiency of the plant.

ADVANTAGES

This prefabricated portable bio waste treatment plant is most suitable for hygienic disposal of treatment of any type of easily degradable organic waste and waste water and for production of cooking gas from it using Anaerobic or bio methanization technology. The design of the plant is such that it is very sleek, compact, durable, portable and user-friendly. One can either produce or manufacture it in factories on demand. So bulk supply and replication of these plants are very easy. The disposal of waste using this eco-friendly technology really helps the society overcome all the environmental issues. All the people can pay their due share by installing a domestic waste treatment plant in their home that would help for treating the waste at the sources, the same day. This portable biogas plant developed can be installed in every household and such installation of those plants would lead to a silent green revolution. Since every household is real source of waste and waste water, feed material is available in abundance. The installation of such a plant would change the concept of people about hygienic waste disposal and tapping the energy of biogas from it. Yet another advantage of this plant is that the liquid organic waste from the kitchen can be treated immediately. Thus every house hold becomes a power house through the generation of bio energy / biogas for cooking purposes from their own house waste.

SUMMARY OF THE INVENTION

The invention pertains to the portable / prefabricated system / plant for the generation of biogas / bio energy from the bio degradable organic waste materials. The system for the generation of the biogas comprises an anaerobic digester for the processing of the bio degradable waste materials and the supplying of the generated biogas to the gas collector placed movably on the top part of the said digester. The organic liquid and the organic solid waste are fermented by the anaerobic microbes in the anaerobic digester for the production of biogas. The additional weight system in the gas collector increases the operating pressure inside the anaerobic digester.

The digester comprises an inlet means for the introduction of the waste materials into the said digester wherein said inlet chamber comprises a hygienic cover and a lock system for holding said inlet pipe and the said inlet pipe is provided without any bends and curvature to prevent the chance of blockage in the said inlet means. Accordingly the digester is provided with a projection for the receipt of the bend less and straight inlet means. The said digester is provided with ribs at predetermined locations for improving the structural strength and additional space at the bottom edge of the outlet means for the block less delivery of the slurry.

OBJECT OF THE INVENTION

i. The important object of the invention is that it reduces the emission and we get a pollution / odor free healthy atmosphere.

ii. The object of the present invention is to provide a portable system for the generation of the biogas through the utilization of bio degradable organic wastes / household waste materials, without the regular use of cow dung.

iii. The another object of this invention is to construct a prefabricated and easily transportable / light weight and easy to install a biogas plant, which is most suitable for hygienic disposal / treatment of any type of easily degradable organic waste and waste water / household waste materials and for production of cooking gas / bio energy from them.

iv. It is another object of the present invention to provide a portable prefabricated digester at the lower portion with inlet and outlet means, a gas collector provided at the top portion of the said plant making the gas generated in the said digester to flow upwards and to be collected in it, the said gas collector being movably placed over the said digester and also fixed in the middle of the said digester with the help of guide frame, the said gas collector being provided with gas flow control means to regulate the supply of gas flow for consumption.

v. It is another object of the present invention is that a predetermined additional weight system inserted in the top of the gas collector i.e., upon the centre guide frame and a cover to cover the additional weight for making it more attractive, will help to equal distribution of pressure in the gas collector.

vi. It is yet another object of the present invention to provide a hygienic cover at the top of the inlet means, and a built in lock for holding the inlet pipe, a projection in the digester to hold inlet pipe for the smooth flow of waste material to the digester and for avoiding the chance of block in the inlet means, ribs placed at the different locations of the digester provide additional strength in the digester and an extra space adjacent to the bottom edge of out let means provides the easily discharge of treated waste.

vii. It is other object of the present invention to provide ribs in the top and sides of the gas collector which provides more strength to the gas collector

viii. It is another important object of the present invention is the extended edge on the top corner of the digester. The extended edge of the gas collector helps to avoid the mix of rain water into the bio waste and to avoid the breed of mosquitoes. It also helps for the free draining of rain water away from the said digester

ix. Another important object is the introduction of scum breaker, which prevents the scum formation of scum (accumulation of treated materials) through the rotation of gas collector.

x. Another important object is the introduction of the lugs systems. The centre guide frame is fixed in the middle of the digester with three lugs. It can be increased according to the size / capacity of the digester.

xi. Another important object of the invention is the introduction of two projections, fixed near to the top end of the centre pipe of the gas collector for the easily lifting of the gas collector from the digester.

xii. Another important object of the invention is the introduction of hygienic cover in the inlet chamber which provides a healthy atmosphere.

STATEMENT OF THE INVENTION

A portable / prefabricated biogas plant comprising:

A. A Digester (1) for processing the bio degradable organic waste materials / household waste materials, and to generate biogas / bio energy a digester is provided at the lower part of the said biogas plant which comprises of:

I. Inlet Chamber (5) for feeding inputs such as bio degradable
organic waste materials / household bio waste materials into the
digester. It flows through the Inlet pipe (2).

II. Projection for holding the inlet pipe (3) is provided for the proper accommodation of the inlet pipe and to avoid the chance of block in the inlet means.

III. Lid / cover (6) placed on the input chamber (5) of the inlet pipe
(2) for enhancing the hygienic atmosphere around the plant.

IV. Lock System (4) for holding the inlet pipe avoid the use of external clips and improve the appearance of the plant.

V. Centre guide frame (7) is fixed in the middle of the digester with three lugs (8). With the help of Centre guide frame (7), the gas collector (13) is centerlized and fixed over the digester (1). The lugs (8) systems can be increased according to the size and capacity of the digester.

VI. Cornish (9) is fixed above the three lugs (8) helps to rest the gas collector and also avoid the leakage / escape of gas generated in the digester through the space between the gas collector (13) and the digester (1) and also helps to direct the generated gas to the gas collector (13).

VII. Outlet pipe (10) is provided for the discharge of effluent from the digester an extra space / curve (11) is provided for the easily discharge of the treated waste.

VIII. Ribs (12) provided in predetermined different locations of the side wall of the digester (1) provide additional strength to the digester.

B. An Expandable Gas Collector (13) is provided for collecting / storing the generated biogas / bio-energy from the said digester. For transmitting the said biogas, an usable medium is provided on the top part of the said gas collector which further comprises:

I. Control valve (15) is provided to regulate the supply of gas flow for consumption or other utility purposes.

II. A predetermined additional weight (16) placed on the top part of the said gas collector to increasing the pressure inside the said gas collector and to correspondingly increasing the flow speed of the biogas from the said gas collector (13) to the external fuel usable medium through the control valve (15).

III. A cover (17) for the said weight (16) enclosing the said weight on the exterior surface.

IV. Scum brakes (21) located at predetermined positions inside the said gas collector (13) for preventing the formation of the scum in the said plant.

V. An extended edge (14) on the top edge surface walls of the said gas collector for the free draining of rain water away from the said digester (1).

VI. Ribs (19) placed at predetermined locations at the top, side and bottom part of the said gas collector for improving the durability and strength of the said gas collector (13).

VII. Two projections (18) are fixed on the top centre of the gas collector, for the easily lifting of the gas collector (13) from the digester.

Brief description of the Drawings and Photographs

Figure 1 in sheet 1 deal with Portable Biogas Digester

> Cross Section view of Portable Biogas Digester
> Interior view of Portable Biogas Digester

Figure 2 in sheet 2 deal with Portable Biogas Collector / Gas holder
> Elevation of Portable Biogas Collector / Gas holder
> Interior view of Portable Biogas Collector / Gas holder

Sheet 3 deal with Photographs of Portable Biogas Digester and Gas Collector / Gas holder

DETAILED DESCRIPTION OF THE DRAWINGS AND PHOTOGRAPHS

Referring to the figures 1 and 2 of the accompanying drawings, the portable prefabricated biogas generating plant consists of a digester (1) and gas collector (13). The digester (1) is the lower portion. The digester has the feed [inlet chamber] (5) and discharge facility [outlet] (10) for loading and discharge of the degradable bio waste material. The gas collector (13) is the top portion having flow control means (15) for regulating the flow of gas to be collected in the gas collector (13) for consumption. The gas collector (13) is movably placed over the digester (1). The gas collector (13) is fixed in the middle of the digester with the help of centre guide frame (7) and centre pipe of gas collector (20).

Figure -1 - Illustrates the digester of the Biogas plant:

The digester (1) is a cylindrical vessel or chamber with insulated side walls and bottom wall or ceiling comprising a suitable insulation material (Fiber Glass Reinforced Plastic (FRP)).

The digester (1) further comprises an inlet chamber (5) connected by a inlet pipe (2), which is made straight for the easy transfer of waste from the kitchen and other sources to the digester. To maintain a hygienic surrounding, a cover (6) has been introduced in the inlet chamber (5). The top cover (6) isolates the bio degradable waste in the digester (1) from the external atmosphere.

To hold inlet pipe (2) in the respective position, an in built lock (4) is provided. This lock has been developed to avoid the use of external clips, and to improve the appearance of the system and to minimize the production time and expense of the overall system. A projection (3) is provided in the digester for proper accommodation of the inlet pipe (2). This projection (3) receives the bend less inlet pipe (2) into the digester (1) and transfers the bio degradable waste material for processing. This will help the smooth flow of waste material to the digester and avoids the chance of block in the inlet pipe. The bend in the inlet pipe (2) is eliminated to avoid the formation of block in the inlet pipe.

An outlet pipe (10) with an extra curve (11) is provided for the easy discharge of the treated waste. The extra space / curve (11) adjacent to the bottom edge of out let (10) is provided to preventing the slurry block in the out let pipe (10).

The centre guide frame (7) is fixed in the middle of the digester with three lugs (8). The number of lug system (8) can be increased according to the size / capacity of the digester.
The centre guide frame (7) is constructed by G I pipe covered with Fiber Glass Reinforced Plastic (FRP).

The gas collector (13) is resting on the digester (1) on a projection called the Cornish (9). The Cornish (9) is fixed above the three lugs (8). It avoid the leakage / escape of gas generated in the digester through the space between the gas collector (13) and digester (1) and also helps to direct the generated gas to the gas collector (13).

The corrugated rib sections (12) provided in the predetermined different locations of the digester (1) in the outer wall of the digester provides additional strength to the digester.

Figure - 2 - Illustrates the Portable Bioqas Gas Collector:
The gas collector (13) is generally cylindrical vessel or chamber with insulated side walls and top wall or ceiling comprising a suitable insulation material (Fiber Glass Reinforced Plastic (FRP)).

The Gas Collector (13) is provided with a control valve (15) which closes in an air-tight manner and supplies the biogas to the stove. The biogas collected in the gas collector flow from the gas collector (13) to the external stove or light through the control valve (15). The control valve (15) may be operated manually for the discharge of the biogas from the gas collector (13).

To improve the flow of the biogas and to increase the pressure in the gas collector (13), a predetermined additional weight (16) is added on the top of the gas collector (13). This additional weight increases the pressure on the gas collector which is translated to the stored biogas. The pressure is translated upon the fast and smooth exit of the biogas through the control valve (15) to the external stove or light. A cover (17) is used to cover the additional weight (16) in order to make it more attractive and visually hide the presence of such weight.

The additional weight (16) is constructed by cement and concrete base. The cover of the said weight is constructed by Fiber Glass Reinforced Plastic (FRP).

During rainy seasons the rain water may pass to the digester through the sides of gas collector (13) and get mixed with the bio waste and as a result of which mosquitoes breed in the top surface of waste materials. To overcome this problem the edge (14) of gas collector (13) may be extended to the outer surface of the digester (1) which prevents the flow of rain water into the digester (1). When rain water falls on the top of gas collector (13), it is directed to flow out through the extended edge (14) in gas collector (13).

The centre pipe of the gas collector (20) will helps to centerlize the gas collector with the help of centre guide frame (7) in the digester (1).

The centre pipe of the gas collector (20) is constructed by G I pipe covered with Fiber Glass Reinforced Plastic (FRP).

While fixing the gas collector (13) over the digester (1), the centre guide frame (7) in the digester (1) will goes inside the centre pipe (20) of the gas collector (13).

Upon the regular usage of the kitchen waste for biogas generation, there is a chance for scum formation in the top surface of the digester (1) which will reduce the efficiency of digester considerably in future. The introduction of scum brakes (21) in the gas collector (13) helps to prevent the scum formation. The scum breaker breaks the scum into disintegrate particles upon the rotation of gas collector (13). The scum formed in the digester (1) is broken by the scum brakes (21) and the treated material flows through the outlet (10) in the digester (1).

Scum breaker (21) is constructed by metal strips covered with Fiber Glass Reinforced Plastic, is fixed at predetermined locations. The number of scum breakers (21) can be increased according to the size and capacity of the plant. The scum breaker (21) is fixed in the centre pipe (20) of the gas collector (13)

For the easily lifting of the gas collector (13) from the digester, two projections (18) are fixed on the top centre of the gas collector.

The gas collector (13) further comprises ribs (19), in the top, bottom and side of the gas collector (13) for considerably increasing the strength of the gas collector. The ribs (19) are provided at pre determined locations in the gas collector (13) to provide durable strength to the gas collector.

The Size and Shape of the invented Portable Biogas Plant

The size of the plant depends upon the availability of waste material. The shape of the plant is cylindrical or rectangular depending upon the space available for the installation of the plant. So there is no shape limitation. The design can be modified depending upon the actual requirements. This is reserved with the inventor and there is no fixed specification for each part of the invention. Any specification can be given to improve the efficiency and waste handling capacity of the plant.

It will be obvious to a person skilled in the art that with the advance of technology, the basic idea of the invention can be implemented in a plurality of ways. The invention and its embodiments are thus not restricted to the above examples but may vary within the scope of the claims.

Further the above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

CLAIMS

A portable prefabricated biogas plant comprises of Digester (1) and Gas Collector (13):

A. Digester (1) for processing the bio degradable organic waste materials / household waste materials, and to generate biogas / bio energy, a digester is provided at the lower part of the said biogas plant which comprises of the following claims:

1. A lid / cover (6) placed on the input chamber (5) of the inlet pipe (2) for enhancing the hygienic atmosphere around the said plant.

2. An inbuilt lock (4) for holding the inlet pipe (2) in the pre determined position has been developed to avoid the use of external clips, and to improve the appearance of the system and to minimize the production time and expense of the overall system.

3. A projection (3) on the side walls of the said digester (1) for the easy and bent less reception of the inlet pipe (2) into the said digester (1).

4. A bent less inlet pipe (2) inserted into the said digester through the said projection (3) for the smooth and block less flow of the bio degradable waste material into the said digester.

5. Ribs (12) provided at predetermined locations of the said digester (1) for providing and enhancing the strength to the said digester.

6. A space (11) carved on the side walls of the said digester at the exit of the outlet pipe (10) from the said digester (1) for the prevention of slurry block in the said outlet pipe.

7. The centre guide frame (7) is fixed in the middle of the digester with three lugs (8) it can be increased according to the size / capacity of the digester.

8. The three lugs system (8) is very compact and it will give more space in the digester area and it will increase the efficiency of the plant.

9. The lugs systems and Centre guide frame in the digester and the Centre Pipe in the Gas Collector is covered with Fiber Reinforced Plastic which will provide the durability and strength.

10. The gas collector (13) is resting on the digester (1) on a projection called the Cornish (9). The Cornish (9) is fixed above the three lugs (8). It avoid the leakage / escape of gas generated in the digester

B. An Expandable Gas Collector (13) is provided for collecting / storing the generated biogas / bio-energy from the said digester. For transmitting the said biogas, an usable medium is provided on the top part of the said gas collector which further comprises the following claims:

11. Ribs (19) placed at predetermined locations at the top and bottom part of the said gas collector for improving the durability and strength of the said gas collector (13).

12. A predetermined additional weight (16) placed on the top part of the said gas collector for increasing the pressure inside the said gas collector and for correspondingly increasing the flow speed of the biogas from the said gas collector to the external fuel usable medium through the control valve (15).

13. A cover (17) for the said weight (16) enclosing the said weight on the exterior surface.

14. For the easily lifting of the gas collector (13) from the digester, two projections (18) are fixed on the top centre of the gas collector.

15. Scum breakers (21) located at predetermined positions inside the said gas collector (13) for preventing the formation of the scum in the said plant.

16. An extended edge (14) on the top surface walls of the said gas collector for the free draining of waste and rain water away from the said digester (1).

The portable biogas plant substantially as herein described with reference to accompanying drawings.