WO2010100309A1 - Method and device for the recycling and exploitation of biodegradable domestic waste produced in the dwellings of a community, by means of biogas-production plants, in order to produce electricity and fertilizer and to heat water - Google Patents

Abstract

The invention relates to a method and device for the recycling and exploitation of biodegradable domestic waste produced in the dwellings of a community, by means of prefabricated biogas-production plants, in order to produce electricity and fertilizer and to heat water. The waste is ground in a grinder provided in the kitchen sinks and is conveyed, by means of a network separate from the sewage network, to a biogas-production plant formed by digesters, where biogas is produced by means of anaerobic digestion. The invention includes safety and control mechanisms, a biogas consumer, a biogas reservoir and a place where the inert material resulting from biodigestion can be deposited. This material can be used as fertilizer. Optionally, the waste can originate from gardens. The biogas is consumed in the consumer and used to produce electrical power, mechanical power or to heat water. The electrical power generated may be fed into the grid.

Description

 Description

PROCEDURE AND DEVICE FOR RECYCLING AND VALUATION OF BIODE-GRADABLE DOMESTIC WASTE PRODUCED IN HOUSING OF NEIGHBORHOOD COMMUNITIES THROUGH BIOGAS PRODUCTION PLANTS TO PRODUCE ELECTRICITY, PAYMENT AND HEATING WATER.

[1] Procedure and device for recycling and recovery of biodegradable household waste produced in homes in neighboring communities, through biogas production plants to produce electricity, fertilizer and heat water.

[2] The invention relates to a method and device for recycling and valorizing all biodegradable household waste produced in homes in neighboring communities, as well as optionally biodegradable waste from gardens.

[3] Biodegradable household waste is first crushed by means of a disposer disposed in the kitchen sinks and then conducted through a separate network independent from the faecal network of the building to a biogas production plant formed by a group of biogas digesters in phases or single stage, the necessary safety and control mechanisms, a biogas consumer, a biogas tank and a place for the deposition of inert material resulting from the biodigestion of organic waste.

[4] In this group of digesters controlled fermentation of organic waste occurs. As a consequence of said controlled fermentation biogas is produced.

[5] The composition of the biogas generated is as follows: methane (CH4), CO2 and other chemical compounds.

[6] Biogas can be used energy through combustion, its calorific value being 4000 to 6000 Kcal / cubic meter.

[7] This biogas is consumed in the biogas consumer, and used for the production of electrical, mechanical or water heating.

[8] For the digestion to take place, the digesters will be fed with the crushed material from the kitchens, and the PH, temperature, dilution of the digester content and biogas pressure will be controlled at all times. The system will be equipped at all points with the control mechanisms that guarantee the correct functioning of the device and its safety.

[9] The system includes a gas storage device. [10] As a result of the fermentation of the waste, it throws an inert product that will be removed from the digesters. Once properly dried, it can be used as fertilizer. The volume and weight of this product is less than the volume and weight of the waste entering the system.

[11] The entire solid by-product of the invention is an organic fertilizer whose weight and dry volume are less than the weight and volume of biodegradable waste that is introduced into the device.

[12] It involves a recovery of waste and a possible beneficial use in agriculture or soil improvement. This is important in areas whose soils suffer from deficits in organic matter or are in the process of desertification.

[13] According to Directive 1999/31 / EC of April 26, 1999, regarding the dumping of waste and origin of Royal Decree 1481/2001 of December 27, which regulates the disposal of waste through landfill deposits, are 'biodegradable waste, all waste that can be decomposed aerobically or anaerobically, such as food and garden waste, paper and cardboard.'

[14] Article 5 of Royal Decree 1481/2001, states that 'The General State Administration and the Autonomous Communities must develop a joint program of actions to reduce biodegradable waste destined for landfills. This program must include measures to achieve the specific objectives that biodegradable urban waste includes in article 5.2. of the aforementioned Royal Decree, in particular through recycling, composting and other forms of recovery such as biogas production through anaerobic digestion. '

[15] Article 5.2, of Royal Decree 1481/2001, states that the following objectives must be achieved:

[16] a) by July 16, 2006, the total amount (by weight) of biodegradable urban waste destined for landfill shall not exceed 75% of the total amount of biodegradable urban waste generated in 1995,

[17] b) by July 16, 2009, the total amount (by weight) of biodegradable urban waste destined for landfill shall not exceed 50% of the total amount of biodegradable urban waste generated in 1995,

[18] c) by July 16, 2016, the total amount (by weight) of biodegradable urban waste destined for landfill shall not exceed 35% of the total amount of biodegradable urban waste generated in 1995.

[19] Currently, household waste is sent to landfill in many cases without prior separation.

[20] The present invention involves a separation of the biodegradable fraction from household waste, so as to facilitate the efficiency of selective collection of urban waste. [21] The present invention assumes, even in the case of landfill disposal of waste residues, a decrease in the volume deposited in landfill.

[22] The present invention involves the energy use of biogas. A ton of biodegradable household waste can produce 330 to 550 cubic meters of biogas. In landfills and under normal conditions it is not possible to recover more than 220 cubic meters of biogas per ton throughout the life of the landfill, and this through the use of complex design and exploitation technologies and only viable in large landfills. In this way, at least about 110 cubic meters of biogas per ton of biodegradable waste would escape into the atmosphere.

[23] Methane is a potent greenhouse gas. A cubic meter of methane has the same greenhouse effect as 23 cubic meters of CO2.

[24] As an order of magnitude, in Spain, 35% of the methane generated comes from landfills and represents 5% of the total greenhouse gases.

[25] On the other hand, the deposit of organic waste in the landfill is a series of drawbacks, such as:

[26] • The release of biogas in the atmosphere.

• The risk of combustion and explosions as a result of the uncontrolled production and release of biogas into the atmosphere, or the formation of biogas bags.

• The instability caused by the mass of waste deposited as a result of the variation in volume that occurs as a result of the degradation of organic matter.

• The instability due to landslides of the mass of waste discharged.

• The difficulty of final closure of the landfill as a result of the instabilities mentioned.

• The possible difficulty of vegetation in landfill closure works as a result of the displacement of oxygen in the substrate.

• The generation of leachates whose characteristics vary depending on their age. In general, they are leachates that initially have acidic pH (although over time years tend to equilibrium pH), they have very high rates of BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand), and may contain a high number of hazardous pollutants, by mobilizing them by dissolution because of their acidic pH. If they are not collected in a controlled manner, they are a potential source of contamination for surface, groundwater and soil in the landfill environment, due to their high potential for ecotoxicity. Even in the case of their collection in a controlled manner, they require very expensive treatments in general to be able to comply with the limits of discharges to channels imposed by water legislation. [27] The present invention prevents the emission of biogas produced by the decomposition of organic matter in landfills. [28] The present invention reduces the risk of combustion and explosions insofar as it uses biodegradable waste by avoiding landfill. [29] The present invention reduces instabilities in landfills by sliding to the extent that it prevents depositing in landfills of biodegradable waste. [30] The present invention facilitates the final closure of the landfill by reducing instability due to the lower deposit in the landfill of biodegradable waste. [31] For the same reason, it reduces the difficulty of vegetation in landfill closure works as a result of the displacement of oxygen in the substrate. [32] To the extent that it reduces the deposit in landfills of biodegradable waste, it reduces the generation of leachate and with it the risks of contamination of water and soil.

Technical sector

[33] This invention falls within the field of urban waste recycling and renewable energy. Prior art

[34] There are documents such as ES 2 233 667 T3, ES 2 268 798 T3, the US-PS

4,594,078, DE-19538579, EP 0 934 938, among many others that refer to the invention of a bioreactor for biomass methanization in which an arrangement and operation of a bioreactor is proposed from the moment the biomass enters in the digester tank until the moment of gas production.

[35] No document determines that the digesters will be fed using biodegradable waste from the kitchens of the dwellings.

[36] No document defines that the biodegradable waste produced in homes will be crushed using a disposer located in the kitchen, preferably in the sink.

[37] No document defines a system for the conduction of the crushed biodegradable waste through a network separated from the faecal network of the building to the bioreactors. Technical problem

[38] The present invention involves the energy use of biogas. A ton of biodegradable household waste can produce 330 to 550 cubic meters of biogas. In landfills and under normal conditions it is not possible to recover more than 220 cubic meters of biogas per ton throughout the life of the landfill, and this through the use of complex and only viable design and exploitation technologies in large landfills. In this way, at least about 110 cubic meters of biogas per ton of biodegradable waste would escape into the atmosphere. [39] Methane is a potent greenhouse gas. A cubic meter of methane has the same greenhouse effect as 23 cubic meters of CO2. [40] As an order of magnitude, in Spain, 35% of the methane generated comes from landfills and represents 5% of the total greenhouse gases. [41] On the other hand, the waste disposal in landfill is a series of drawbacks, such as:

• The release of biogas in the atmosphere.

• The risk of combustion and explosions as a result of the uncontrolled production and release of biogas into the atmosphere, or the formation of biogas bags.

• The instability caused by the mass of waste deposited as a result of the variation in volume that occurs as a result of the degradation of organic matter.

• The instability due to landslides of the mass of waste discharged.

• The difficulty of final closure of the landfill as a result of the instabilities mentioned.

• The possible difficulty of vegetation in landfill closure works as a result of the displacement of oxygen in the substrate.

• The generation of leachates whose characteristics vary depending on their age. In general, they are leachates that initially have acidic pH (although over time years tend to equilibrium pH), they have very high rates of BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand), and may contain a high number of hazardous pollutants, by mobilizing them by dissolution because of their acidic pH. If they are not collected in a controlled manner, they are a potential source of contamination for surface, groundwater and soil in the landfill environment, due to their high potential for ecotoxicity. Even in the case of their collection in a controlled manner, they require very expensive treatments in general to be able to comply with the limits of discharges to channels imposed by water legislation.

Technical solution

[42] Biodegradable household waste is first crushed by a disposer disposed in kitchen sinks, preferably under them and then conducted through a separate network independent from the faecal network of the building to a biogas production plant formed by a group of digesters in phases or single-stage, the necessary safety and control mechanisms, a biogas consumer, a biogas tank and a place for the deposition of inert material resulting from the biodigestion of organic waste.

[43] In this group of digesters controlled fermentation of organic waste occurs. As a consequence of said controlled fermentation biogas is produced.

[44] The composition of the biogas generated is as follows: methane (CH4), CO2 and other chemical compounds.

[45] Biogas can be used energy through combustion, its calorific value being 4000 to 6000 Kcal / cubic meter.

[46] This biogas is consumed in the biogas consumer, and used to produce electrical, mechanical or water heating.

[47] For the digestion to take place, the digesters will be fed with the crushed material from the kitchens, and the PH, temperature, dilution of the digester content and biogas pressure will be controlled at all times.

[48] The system will be equipped at all points with the control mechanisms that guarantee the correct functioning of the device and its safety.

[49] The system includes a gas storage device.

[50] As a result of the fermentation of the waste, these are transformed into an inert product that will be removed from the digesters. Once properly dried, it can be used as fertilizer.

[51] The volume and weight of the inert product that is formed as a result of the biodigestion of organic waste is less than the volume and weight of the waste entering the system.

[52] The entire inert by-product of the invention is an organic fertilizer whose weight and dry volume are less than the weight and volume of biodegradable waste that is introduced into the device.

Advantageous effects

[53] The present invention reduces the emission into the atmosphere of biogas, one of whose components is methane gas, which has a potent greenhouse effect.

[54] Biogas can be used energy through combustion, its calorific value being 4000 to 6000 Kcal / cubic meter.

[55] This biogas is consumed in the biogas consumer, and used for the production of electrical, mechanical or water heating.

[56] As a result of the fermentation of the waste, the invention yields an inert product that will be removed from the digesters. Once properly dried It can be used as fertilizer. [57] The volume and weight of this product is less than the volume and weight of the waste entering the system. [58] The present invention reduces the risk of combustion and explosions insofar as it uses biodegradable waste by avoiding landfill. [59] The present invention reduces instabilities in landfills by sliding to the extent that it prevents depositing in landfills of biodegradable waste. [60] The present invention facilitates the final closure of the landfill by reducing instability due to the lower deposit in the landfill of biodegradable waste. [61] For the same reason, it reduces the difficulty of vegetation in landfill closure works as a result of the displacement of oxygen in the substrate. [62] To the extent that it reduces the deposit in landfills of biodegradable waste, it reduces the generation of leachate and with it the risks of contamination of water and soil.

Brief description of the figures

[63] FIGURE 1 schematically depicts the operation of the invention, which consists of the following elements: [64] • Crusher of organic waste in each of the community kitchens

(one).

• Separate network of sink wastes (2) from kitchens independent of the faecal network (3) from homes.

• Storage tank and previous waste treatment (6) (in community facilities).

• Valve to pour excess water (7) to the faecal network. (3)

• Biogas plant (4), which is schematically represented by:

• Food of the digester.

• Biodigester (Waste treatment center and biogas producer. (8)

• Biogas storage). (9)

• Digestate collection systems or what is the same effluent for fertilizer. (10)

• Biogas consumer. (5)

• Gas excess burner. (eleven)

• Electricity generating device. (13)

• Water heating system. (14)

• Security and control systems.

Claims

Claims [1] New procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and heat water, which consists of the following stages: - Shredding of all biodegradable organic waste produced in each of the kitchens that make up the community of neighbors using a shredder placed for this purpose. - A separate network for the transport of all organic waste produced in the kitchens and crushed, independent of the building's fecal network. - Biomass storage tank - Anaerobic digestion of waste using a plant that produces biogas. - Adequate treatment of the digestate to produce fertilizer. - Placement of a biogas consumer. - Electrical energy generator from the biogas consumer - Water heating device from the energy produced by the biogas consumer. - Process automation. - Security systems throughout the process. [2] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity and fertilizer and heat water according to claim 1 is characterized in that the organic waste crusher installed In the kitchen, by crushing waste at the source, it prevents its accumulation, contamination of the premises, and the consumption of plastic bags for separate treatment, in addition to avoiding its transfer to landfill, avoiding gas pollution in landfill and reducing transportation. of biodegradable waste to it. [3] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and hot water, according to claim 1 is characterized in that the separating network of Gravity transport of waste along with water is arranged continuously independently of the building's fecal network, and is common to all the homes in the building. [4] The new procedure for recycling and recovery of organic waste produced in kitchens in neighboring communities, through biogas plants to produce electricity, fertilizer and heat water, according to claims 1, 2 and 3, it is characterized in that the waste is transformed by the biodigester into biogas, thereby not contaminating way the landfills. [5] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity and fertilizer and heat water according to claims 1, 2,3 and 4 is characterized by that the gas produced is used to generate electricity that is reintroduced into the electrical grid. [6] The New procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity and fertilizer and heat water according to claims 1, 2, 3 and 4 is characterized by that the gas produced is used to heat water that will be used as domestic hot water in the building. [7] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and heat water, in accordance with claims 1,2, 3, 4, is It is characterized because it can optionally be fed with organic remains from the gardens of the neighboring communities themselves. [8] The New procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and heat water, in accordance with claims 1,2, 3, 4, 5 , 6 and 7 is characterized by the production of a digestate that can be used as fertilizer. [9] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and heat water, according to claim 1 is characterized in that the system is controlled automatically. [10] The new procedure for recycling and valorization of organic waste produced in kitchens in neighboring communities, using biogas plants to produce electricity, fertilizer and heat water according to claim 1 is characterized in that the entire system is protected by security systems.