RU2372155C1 - Method of obtaining biogas and fertiliser from organic wastes - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to methods of organic wastes utilisation, namely to method of their recycling into biogas and fertiliser. Method includes preparation of base from hydrolysing material, assembling gas-drainage construction from rigidly connected pipes combining functions of vertical and horizontal gas drainage; sorting and crushing of wastes, their inoculation with methanogenic microorganisms and moisturising; filling layer-by-layer by pouring from upper part of gas-drainage construction with sprinkling of layers with gas-and-water-proof material; biogas is removed via gas-drainage construction, filtrate being removed via hydrodrainage system, mounted into base. Recycled by anaerobic microorganisms biomass can be used as fertiliser. After installation discharge cycle of wastes recycling is repeated.

EFFECT: simplification of method of organic wastes recycling into biogas and fertiliser, ensuring reliability of biogas removal from biomass bulk and cyclicity of wastes recycling process.

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Description

The invention relates to methods for the disposal of organic waste, and in particular to methods for anaerobic processing of organic waste from agriculture, the food industry into biogas and fertilizers.

Dozens of articles, reviews, patents are devoted to methods of anaerobic processing of organic waste into biogas.

Of the known methods, the closest technical solution is “A method for collecting and discharging biogas and filtrate at solid waste landfills in ravines and terrain folds” (see patent RU No. 2242299, class B09B 1/00, B09B 3/00, 2004), which we have chosen as a prototype.

The specified method for collecting and discharging biogas and filtrate at the landfill includes preparing the base, installing a vertical gas drainage system, layer-by-layer waste stacking with insulating layers, installing a horizontal gas drainage system, insulating the surface of the formed landfill, on the prepared base in pits distributed over the landfill area install polymer rings with blind walls and a bottom, on which vertical gas drainage wells built up from polymer are equipped x rings with perforated corrugated walls. The waste is laid in layers with an insulating layer of inert material, such as sand or slag, sprinkled in two stages - first to the middle of the polymer ring with corrugated walls, then to the design layer height, the horizontal gas drainage system is installed after the first stage of laying the waste in the holes of the polymer ring with corrugated walls in the form of polymer perforated corrugated pipes with plugs at the ends. The biogas and filtrate are removed by a gas collector and airlift installed inside the well using polymer pipelines. Next, the cycle is repeated until the design height of the landfill is reached, the last layer of waste is covered with a layer of external waterproofing from film or other material. The upper end of the well in each building cycle is equipped with a plug with holes for polymer pipelines for biogas and filtrate removal and is brought to a height exceeding the mark of each waste layer. Waste is laid out sequentially in layers over the entire landfill area with a repetition of the cycle of work on each fill card.

The main disadvantages of this method:

- a high probability of curvature or breakage of horizontal tubular drains with disruption of the joints of the gas drainage system during natural shrinkage of biomass, as well as clogging of holes of perforated tubular drains with wet waste when the protective filter material of drains is displaced;

- the considered method does not provide for the return to industrial circulation of the second valuable component of the processing of organic waste - organic fertilizers.

The purpose of the invention is to increase the efficiency and expand the technological capabilities of processing organic waste into biogas and organic fertilizer.

The specified technical result is achieved in that a method for producing biogas and fertilizer from organic waste, including preparing the base from a waterproofing material, installing a gas drainage system, layer-by-layer waste packing with bedding with soil materials, removal and collection of biogas and filtrate, according to the invention, on a prepared base from waterproofing material mount a gas drainage structure of rigidly connected pipes, combining the functions of vertical and horizontal gas drainage; Before laying on the base, organic waste is sorted, crushed, seeded with methanogenic microorganisms, moistened, laid with a layer of it from the top of the gas drainage structure in layers in several stages to the projected pile height, with each layer of waste being sprinkled with a clay layer; to seal the waste layers, the clay is irrigated with a disinfected filtrate or water and dried to form a hard crust; when the design height of the shoulder is reached, the last layer of waste is sealed like the lower layers; biogas is diverted through the gas drainage structure, and the filtrate is drained by a hydrodrainage system mounted in a waterproofing base; and disinfect; after the cessation of biogas evolution, the biomass processed by microorganisms is removed and used as fertilizer; then the cycle of processing organic waste is repeated.

Using the proposed technical solution will allow you to get the following result:

- simplify the method of processing organic waste;

- to ensure the reliability and completeness of biogas selection from recyclable waste due to the gas drainage structure from rigidly connected pipes, combining the functions of vertical and horizontal gas drainage;

- use recycled organic waste as fertilizer;

- reduce the size of land allocated for waste disposal due to the cyclical nature of the processing process;

- minimize the industrial impact of waste on the environment.

The method of producing biogas and fertilizer from organic waste, including preparing the base from waterproofing material, installing a gas drainage system, layer-by-layer waste packing with bedding with soil materials, removal and collection of biogas and filtrate, differs from the known one adopted for the prototype in that the prepared a base of waterproofing material is installed gas drainage design of rigidly connected pipes, combining the functions of vertical and horizontal gas drainage; Before laying on the base, the organic waste is sorted, crushed, seeded with methanogenic microorganisms, moistened and laid with the bulk from the top of the gas drainage structure in layers in several stages to the projected height of the pile, with a layer of clay sprinkling each layer of waste; to seal the layers of waste, the clay layers are irrigated with a disinfected filtrate or water and dried to form a hard crust; when the design height of the shoulder is reached, the last layer of waste is sealed like the lower layers; biogas is diverted through the gas drainage structure, and the filtrate is drained by a hydrodrainage system mounted in the waterproofing base and disinfected: after the biogas evolution ceases, the biomass processed by microorganisms is removed and used as fertilizer; then the cycle of processing organic waste is repeated.

A comparable analysis of the proposed method with the known allows us to conclude that the proposed technical solution meets the criteria of the invention of "novelty."

From the well-known patent and scientific and technical literature, there is no known method for producing biogas and fertilizer from organic waste, in which the waste is sorted, crushed, sowed with methanogenic microorganisms, moistened, layered layer by layer from the top of the gas drainage structure with a layer of waste before laying waste onto a prepared base. gas tight material; biogas is diverted by a gas drainage structure, and the filtrate is removed by a hydrodrainage system and disinfected; processed biomass is used as fertilizer, which allows to achieve the technical effect described above. Thus, the proposed solution meets the criteria of the invention of "inventive step".

The claimed technical solution can be used for the processing of organic agricultural waste, vegetable waste from food enterprises, food waste from settlements into biogas and fertilizer with a minimal technogenic load on the environment. Thus, the proposed solution meets the criteria of the invention of "industrial applicability".

The inventive method of producing biogas and fertilizer from organic waste is carried out using a device, a diagram of which is shown in the drawing.

The method is carried out in the following sequence. The sorted organic waste is crushed in apparatus 1. The crushed biomass is transferred by conveyor 2 to conveyor 5, and it is seeded with methanogenic microflora from the sowing tank 3, then the biomass is irrigated with disinfected filtrate or water from irrigation 4 to a moisture content of 50-75%. Next, the moistened biomass is fed by a conveyor 5 to the upper part of the gas drainage structure 6 and poured down onto a specially prepared base 8.

The waste is poured in layers, in several stages, to a total projected shoulder height of 7, with regular layers of waste being sprinkled with clay layers. So, upon reaching the estimated height of the first layer of waste, it is covered with an insulating clay layer and sealed by irrigation of clay with decontaminated filtrate or water from the irrigator 11 and drying the wet clay layer to form a hard crust. After sealing the first layer of waste, it is filled up with the next layer of waste to the estimated height and is sealed in the same way. Upon reaching the overall design height of the pile 7, the last layer of waste is sealed with clay as well as the lower layers of waste.

The selection of biogas from the waste mass is carried out through the gas drainage structure 6. It is mounted in the center of the base 8 and is a rigidly connected pipe structure that combines the functions of vertical and horizontal gas drainage. Horizontal gas drainage pipes are radially mounted in a vertical gas drainage pipe at an angle close to 45 ° (angle of repose of bulk material). At the joints with the vertical pipe, the horizontal drains are equipped with valves 12, and on the opposite side they are open and cut at the bottom at an angle to increase the biogas entry area. As the layers of waste are sealed, the valves open.

The selection of the filtrate is carried out by a hydraulic drainage system 9, mounted in the base 8, which is made of a solid waterproof material with a slope to the center of not more than 15 °.

The filtrate collected by the hydrodrainage system 9 is transferred to a collector 10 and then to a container 4 for disinfection. After disinfection, part of the filtrate enters the sowing tank 3, where it is seeded with methanogenic strains. A part is spent on moistening biomass and clay, and the main part of the filtrate is transferred to cleaning or moistening landfills and solid waste.

Upon termination of biogas evolution, the contents of the pile are crushed, sieved to remove mechanical impurities, and used as organic fertilizer.

After cleaning the site, the cycle of processing organic waste into biogas and fertilizer is repeated.

Claims (1)

A method of producing biogas and fertilizer from organic waste, including preparing the base from waterproofing material, installing a gas drainage system, layering waste, removing and collecting biogas and filtrate, characterized in that a gas drainage structure of rigidly connected pipes is installed on the prepared base, combining the functions of a vertical and horizontal gas drainage; Before laying on the base, the organic waste is sorted, crushed, seeded with methanogenic microorganisms, moistened and laid with the bulk from the top of the gas drainage structure in layers in several stages to the projected height of the pile, with a layer of clay sprinkling each layer of waste; to seal the layers of waste, the clay layers are irrigated with a disinfected filtrate or water and dried to form a hard crust; when the design height of the pile is reached, the last layer of waste is sealed with clay as well as the lower layers of waste; biogas is diverted through the gas drainage structure, and the filtrate is drained by a hydrodrainage system mounted in the waterproofing base, and disinfected; after the cessation of biogas evolution, the biomass processed by microorganisms is removed and used as fertilizer; then the cycle of processing organic waste is repeated.

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