ES1228161U - Organic Waste Management System (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

System that allows the treatment of Residual Organic Material (MOR) by biomethanization, characterized by MOR collection from two networks, kitchens and toilets, which have elements that allow ventilation in its upper part and meet in its lower part in a mixing/homogenization tank/tank, from which the mixture moves by gravity through ducts to the biomethanization unit. (Machine-translation by Google Translate, not legally binding)

Description

SYSTEM FOR THE MANAGEMENT OF ORGANIC WASTE

DESCRIPTION

TECHNICAL SECTOR

The present invention refers to a system for local recycling of the Residual Organic Material generated in the building, obtaining three usable elements: biogas, compost and purified water. The system incorporates a previous treatment of the matter (crushing and mixing of kitchen waste, toilet and paper / cardboard) that optimizes the production of biogas, reducing the anaerobic fermentation times and improving the quality of the compost obtained.

STATE OF THE PREVIOUS TECHNIQUE

The decomposition of organic waste through its biomethanization, to obtain biogas and organic compostable effluent, has already a remarkable degree of technical development, having proposed highly efficient anaerobic digester designs. The type of installation scheme for anaerobic digestion of Organic Matter consists of a biogas reactor or bio-reactor, where a mixture of Organic Matter and Water enters.

This mixture is usually presented in a ratio between 1: 5 and 1: 3. Using a higher ratio of Organic Matter would make it difficult to circulate the mixture and cause it to jam (in the bio-reactor or in the ducts), while if the percentage of Organic Matter were lower, force it to build unnecessarily large bio-reactors that provide ratios of generation of reduced biogas in relation to its capacity.

Anaerobic digestion of Organic Matter is produced in the bioreactor, generating biogas. This digestion can be carried out at room temperature (psychophilic process, eg, installations in small farms in developing countries), at a temperature around 35 ° C (mesophilic process) or at temperatures around 55 ° C (thermofilm process) ).

In installations where reaching temperatures of 55 ° C is not a problem and the Residual Organic Material incorporates human excrement, it is usually considered the thermo-plastic process as the optimal one, since a high production of methane is achieved in a short period of time, and the pasteurization of organic matter is guaranteed (destruction of a higher rate of pathogens).

However, it must be taken into consideration that the thermophilic process is more sensitive to the presence of elements inhibiting fermentation (e.g., ammonia ...).

Two fluids come out of the biogas reactor:

• In gaseous form, biogas (with 60-70% methane and the rest CO2 and other gases) through a conduit located at the top

• In effluent form, digestate, through a duct located in the lower part, opposite to the supply duct of Residual Organic Material

Both products can be used in other processes.

The biogas can be used or stored locally, or transported to different consumption points

The digestate can be used as agricultural fertilizer, being necessary to eliminate part of the water first. For this there are several systems, with the usual centrifugation, and subsequent filtration (ultrafiltration and reverse osmosis are the most common filtering processes) and / or evaporation, to get water that can even be potable.

Some systems incorporate digestate heat recuperators [in thermoplastic systems, the digestate leaves the tank at 55 °, so it is possible to recover this heat for the process), or recover the filter material (ultrafiltrate and osmosis) that reintroduce to the bio-reactor or incorporate the residue for fertilizer.

Optionally, different additions of substances that reduce the action of inhibitors can be made (eg, adding H2SO4 before the bio-reactor reduces the negative impact of Ammonia on the formation of biogas), or that increase the production of biogas (it is being investigated in the present the possibility of adding metal nano-particles in the digester, which could increase the production of biogas up to 3 times).

EXPLANATION AND OBJECTIVE OF THE INVENTION

A scheme of management of the Residual Organic Matter (MOR) in the buildings is proposed, which facilitates its local treatment by anaerobic digestion, obtaining biogas, optimum compost for its use as fertilizer, and purified water. It is therefore a process that contributes to the closure of Organic Matter (OM), the reduction of dependence on oil (as well as the negative environmental impacts linked to prospecting and oil extractions, eg, fracking), and the GHG Footprint .

The need - and beneficial effect - to close the cycles of the Organic Matter (OM) eliminating the character of 'residue' of a large amount of MOR that was originating in the cities was put as early as 1898 by Ebenezer Howard, and with greater intensity by numerous theorists throughout the twentieth century (Odum, William Rees, Girardet, ...), being a widely accepted need today. To achieve this, it is necessary to design circuits that allow the reuse of Residual Organic Material of human origin, which is produced mainly in agricultural spaces -sean production or post processing- and buildings with residential and hospitality facilities.

However, the analysis of the state of the art shows an uneven development of MOR recycling systems. While there are already efficient MOR recycling systems available for their implementation in farms linked to agriculture and the food sector, there is a lack of proposals for their recycling in other types of buildings, and more specifically in non-industrial or agricultural buildings, where generated large amount of MOR. We do not currently find proposals for recycling the MOR in residential construction (hotel, hospital, collective housing) or teaching (institutes, schools, universities), where dining services sometimes generate high amount of MOR, which adds to the one generated by the habitual use of the toilets.

Therefore, a system that facilitates the closure of the MO cycle is proposed. The system is designed especially for buildings that involve uses with high and constant occupation: schools, residences, hotels, jails and collective housing. It can also be implemented in single-family homes or in isolated establishments that produce a lot of organic matter (e.g., restaurants).

The system proposes the collection of the great majority of MOR produced in these buildings, considering two main points of generation: kitchen spaces and toilets (toilets), their processing and mixing, and later anaerobic digestion. It is proposed the collection and mixing of both types of MOR to take advantage of their joint treatment, such as:

• The high presence of anaerobic digestion bacteria in human excrement facilitates the digestion of kitchen waste, in which the presence of said bacteria is very reduced.

• The greater contribution of Carbon from kitchen waste facilitates a residue with a higher C: N equilibrium, and therefore, greater aptitude as a fertilizer.

In addition, the introduction into the process of a percentage of the residual paper / cardboard generated in the building is proposed, in order to optimize the C / N ratio of the resulting fertilizer. For this, in installations in houses, it is recommended to the users to pour in the point located in the space of the kitchen between 15-20% of the production of paper / cardboard discarded (choosing the waste of worse quality and with lower rate of whitening - if possible raw carton - that contains less inhibitors and is also more difficult to reincorporate the recycling cycle of paper / cardboard, and free of non-organic extraneous elements -eg, staples ...-), which will contribute to optimize the C / N content of resulting compost. In installations in other types of buildings, it is necessary to study the production of food, feces and local waste paper / cardboard, to estimate what is the optimum percentage of paper / wasteboard to be incorporated into the system.

Prior to the mixing of these types of MOR, the waste generated in the kitchens and paper / cardboard is treated by grinding. This treatment has two objectives:

• reduce the size of the particles, which allows us to transport them through the sanitation network, avoiding their obturation.

• exponentially increase its exposure surface to the action of bacteria, reducing the time of digestion, and therefore, the volume of the bio reactor.

The above mixture, already ground and homogenized, is conducted from a mixing chamber / tank to the biomethanization unit. In this way, the MOR that reaches the biogas reactors fulfills two characteristics:

• The mixture has a solids / water content of approx. 1: 4, which is considered optimal to be driven by gravity and / or pumping, and not cause jams in the system.

• Vegetable residues, fresh animals and paper / cardboard have been crushed to a reduced size, exponentially increasing the degradation surface per action of bacteria, so the time required for decomposition and anaerobic fermentation is reduced exponentially.

• It incorporates excrements that are already in the anaerobic fermentation phase (they incorporate anaerobic fermentation bacteria), accelerating the subsequent biomethanization process and compensating for the loss of bacteria in the effluent of the bio reactor.

As for the products obtained from the process, all of them may have the nature of a resource suitable for use in other processes:

• The biogas generated can be used locally, or sold to an external agent.

• The effluent can be used as agricultural fertilizer, thus being reincorporated into the Organic Matter cycle, replacing chemical fertilizers that are no longer necessary.

• Additionally, the water could be purified in depth through some complementary process, or be discharged into the sewage network, but with a very reduced organic load.

In this way, it contributes to close practically the cycle of the Organic Matter in the edification (only 80% of the paper-cardboard is excluded, whose cycle must be closed through the usual recycling systems), eliminated as! the concept of Residual Organic Matter, with great environmental advantages:

• Reduction of a large percentage (in volume, but also in weight) of the domestic trash bag, and therefore the effort of transporting it to landfill. Additionally, by eliminating the organic remains of the garbage bag we reduce the need (frequency) of garbage collection in the cities, by eliminating the health risk due to the accumulation of organic matter in decomposition.

• Elimination of the discharge of Organic Matter to landfills, and therefore of the CH4 emissions generated in landfills due to their decomposition, with the consequent reduction of the GHG Footprint.

• Significant reduction of energy footprint and GHG, if the biogas produced is used to replace other sources of non-renewable energy.

• Reincorporation of the Organic Matter to the cycle through its use as agricultural compost, eliminating the need for artificial fertilizers. Soils are one of the best carbon sinks, and fertilizing the soil through compost is a way to take advantage of the soil as a 'carbon sink'. Adding the percentage of paper / carton explained, increases the carbon content of the resulting compost, and with it the function of 'carbon sink'.

• Huge reduction of the Gray Footprint of the cities (currently caused mainly by the discharge of Organic Matter in sanitation) and appreciable reduction of the Gray Footprint of agriculture (caused above all by the use of liquid manure fertilizers, which pollute both superficial and underground aculferos).

Additionally, the biogas and compost generated have a high ease of commercialization, while the great reduction in the amount of waste that needs to be transported to landfill implies a significant reduction in waste collection costs. All this implies that there is an appreciable economic benefit, an important part of which is an increase in GDP (transforming waste into resources), contributing to reduce the current significant economic unsustainability of Spanish society.

It is therefore a scheme with significant implications for the reduction of the current high and growing unsustainability of our cities in its three dimensions:

• Environmental, linked to the excessive energy footprint (with its dependence on the exterior and negative impacts associated with new oil prospecting); to the excessive GHG footprint (linked to Climate Change, whose effects are beginning to be noticeable in some parts of the planet), to eutrophication due to the gray footprint contamination of aculferos (eg, Mar Menor in Murcia),

• Social, since the use of the current 'organic waste' involves the conversion of 'garbage' into 'wealth' contributing to alleviate the current and growing energy poverty, maximized by the possibility of using the biogas generated in the process.

• Economic, since the implementation of the proposed system involves the creation of net wealth, and therefore a net increase in GDP, together with the creation of numerous sustainable jobs, and the reduction of the management costs of the municipalities, greatly reduce the cost allocated to the management of the RU.

It must be borne in mind that establishing an own and differentiated cycle of the Residual Organic Material in origin implies to increase notably the rates of recycling with respect to the systems that separate in landfill, that face problems of presence of impropies that hinder the biomethanization process , etc...

DESCRIPTION OF THE DRAWINGS

Figure 1, scheme of sink unit to install at point of spillage of water and organic waste.

Figure 2, scheme type of installation in restaurant.

Figure 3, scheme type of installation in building use Ensenanza (College, Institute, University, ...), Barracks, Carceles. In buildings for hotel or hospital use, it is necessary to prevent the spillage of toxic substances, or limit the later use of the compost to non-food crops (e.g., energetics).

Figure 4, scheme type of installation in collective housing building

Figure 5, scheme of operation of type biomethanization unit.

Note: The schemes are illustrative and not limiting.

DETAILED DESCRIPTION OF THE INVENTION

The installation in a residential building with provision for commercial premises on the ground floor and accessible roof is described.

In each kitchen there is a pour point of residual organic matter [leftovers of cooked or uncooked food] (1). The user pours at this point the MOR, which reaches a shredder (2), from which the mixture of crushed MOR and water is moved by gravity to an exclusive drain network (4). This pouring point is therefore different from the washing point for utensils or dishes (3), which will separate the network from sanitation (5) making it difficult for the entry of substances inhibiting anaerobic digestion -eg, detergents, bleach ...-.

The excrements are collected from the toilets themselves (6), connected to a network of black water (7) that leads them to a retention chest of foreign bodies (8) and then a crusher (9).

On the ground floor, connection forecast points (10) are left to the network (4) where the location of kitchens is foreseen, and connection (11) to the network (7) in areas where the location of toilets is foreseen.

The two networks (4) and (7) that carry the MOR, have elements that allow their ventilation in the upper level (12) and join in their lower part in a chamber / tank of mixing and homogenization (13), from the which the mixture moves by gravity through ducts (14) to the biomethanization unit (15). The design of this unit may vary according to the type of building and specific location.

A typical system can be (a description of a two-phase bioreactor is given below, but one-phase, or other types of bio-reactor systems can be designed):

• Two digester tanks (15A and B) in series to maximize the extraction of biogas.

The effluent inlet from the mixing box is produced in tank 15a (15.1), and at least tank 15B must have a thermophilic digestion process at 55 ° C, to guarantee the pasteurization of the waste and 'harmlessness' of the effluent at the outlet ( 15.3). • Both tanks will have an exit at the top whereby the biogas (15.2) that is generated is released, which is stored locally in a tank (16) from which it is channeled to an external network that allows its distribution (16.1). ), or is supplied (16.2) for local power generation (17). In the latter case, biogas can be used for local heat generation - which can be supplied to the biomethanization tanks (17.1) or in the subsequent evaporation phases of the effluent (17.2) - or electricity, in which case it can be poured into a external network (17.3).

• The biomethanization tank 15A will also have an outlet in its upper part, so that the effluent moves to tank 15B (15.A.1). This second tank, in turn, will have an outlet in its lower part and opposite the entrance of the tributary (15.B.1). The effluent of this tank is inert, and we will proceed to treat it for its separation in compost and water (18). For this, two stages are carried out:

^o Separation of the thickest part of the solid waste from the water by centrifugation (18 A)

^o Separation of the fine solids by filtering (18B) - can also include two stages, for example an ultrafiltrate and reverse osmosis.

After this process we obtain a solid waste, which we can market as fertilizer (18.1) and a liquid part (water) that we can take advantage of for secondary uses or pour into the sewerage network (18.2), or derive (18.3) to a purification treatment more intense (19) -eg, by evaporation to vacloobteniendo purified water (19.1).

Claims (3)

1. System that allows the treatment of the Residual Organic Matter (MOR) by biomethanization, characterized by collection of MOR from two networks, kitchens and toilets, which have elements that allow its ventilation in its upper part and join in its lower part in a mixing / homogenization tank / tank, from which the mixture moves by gravity through ducts to the biomethanization unit. 2. System that allows the treatment of the Residual Organic Matter (MOR) by biomethanization, according to claim 1, characterized in that the collection of MOR in the first network is carried out in food dumping points and certain types of paper / cardboard in sinks of kitchens, passing later by a shredder, from which the mixture of crushed MOR and water is moved by gravity to an exclusive drain network. 3. System that allows the treatment of the Residual Organic Material (MOR) by biomethanization, according to claim 1, characterized in that the collection of MOR in the second network is made from excrements collected from the toilets themselves, connected to a water network black that leads them to a retention box of foreign bodies and then to a shredder.