WO2022096940A1

WO2022096940A1 - Biocell, plant and method for treating organic waste

Info

Publication number: WO2022096940A1
Application number: PCT/IB2021/052435
Authority: WO
Inventors: Jacopo LIOTTI; Francesco Guzzo; Pasqualino ALLEGRO; Davide MAINIERI
Original assignee: Isgreen S.R.L. Start-Up Costituita A Norma Dell'art. 4 Comma 10 Bis Del Decreto Legge 24 Gennaio 2015 N.3
Priority date: 2020-11-09
Filing date: 2021-03-24
Publication date: 2022-05-12
Also published as: EP4240541A1; IT202000026636A1

Abstract

Described is a biocell (1) for the treatment of organic waste comprising a main body (2) defining a containment space for a quantity of organic waste to be treated, an upper inlet hole (3) configured for the insertion of soldier fly larvae and the quantity of organic waste to be treated using the soldier fly larvae in such a way as to obtain vermicompost, upper outlet holes (4) for the soldier fly larvae and a lower outlet hole (8) for the vermicompost and, if necessary, excess waste material.

Description

Title of Invention: BIOCELL, PLANT AND METHOD FOR TREATING ORGANIC WASTE

[0001] This invention relates to a biocell for treating organic waste. The invention also relates to a plant comprising a plurality of the above-mentioned biocells and a method for the treatment of organic waste.

[0002] The term "organic waste" means organic refuse, agricultural by-products, livestock sludge, waste from the farming industry, digestate from anaerobic digestion, purification sludges and similar waste.

[0003] In other words, the invention relates to the sector for the management of waste and by-products of the livestock and agro-industrial sectors. The waste management sector is one of the greatest problems in the world and represents a crucial factor for the future. The disposal costs require public and/or private administrations to divert considerable funds in order to manage the waste produced by local inhabitants, tourists and industrial processes. The handling of waste is very varied and complex but that of the organic fraction is without doubt one of those which, if not managed correctly, can generate a large amount of problems.

[0004] More specifically, the organic waste management sector must deal with a series of legislative requirements deriving from the hazards of treating a non-inert material which therefore interacts with the surrounding environment.

[0005] Currently, the technologies used for the management of organic wastes (or organic matrices) are mainly aerobic composting and anaerobic digestion, and to a lesser extent thermal units (such as incinerators) and landfill sites. These technologies are very expensive and difficult to manage and maintain, both in terms of safety at the workplace and with regard to environmental problems, also linked with public health issues. The compost resulting from the treatment must in fact be free of pollutants and pathogens in order to be used as a soil fertiliser, otherwise it must be disposed of in landfill or in incinerators.

[0006] Disadvantageously, organic waste is a material which can putrefy extremely easily, this means that it produces hazardous molecular compounds, unpleasant odours and is attractive to a series of animals and insects which can be a carrier of disease and are often also infestant.

[0007] Disadvantageously, various greenhouse gases (water vapour and CO2) as well as other hazardous gases such as, for example, H2S and nitrogen oxides (NOx) are also produced in anaerobic digestion processes and in aerobic composting processes.

[0008] Disadvantageously, due to the degradation phenomena, there is the production of percolate, especially during the transport and storage step, which is highly dangerous for soils and ground waters.

[0009] Disadvantageously, the compost produced is of low quality, remains stored for long periods, especially in winter when the agricultural sector does not require it, and occupies space and sometimes becomes a cost because it must be disposed of in landfill if it does not fall within the legal parameters.

[0010] Disadvantageously, the aerobic composting plants occupy a large area of land, consumes a great deal of energy (approx. 70 kW for each tonne waste received), are very long processes and are often the source of unpleasant odours as for some anaerobic processes.

[0011] Anaerobic digestion systems have much higher performance levels, produce few or no odours, occupy little space, produce biogas (methane and carbon dioxide) which can be burnt to produce heat and electricity, or the biomethane may be refined and sold. Disadvantageously, the anaerobic digestion plants are expensive plants, which are not designed to be used by small mountain communities and small villages in general. In addition, the waste introduced must be as fresh as possible to maximise the production of biomethane. The waste which arrives from afar has in fact already partly started to ferment with the consequence of reducing the production capacity and with the formation of unpleasant odours and percolate.

[0012] A new technique for the management of organic waste is currently being developed, which comprises the use of soldier fly larvae. The use of the soldier fly larvae allows the organic waste to be treated very quickly, giving vermicompost without pathogens as the final result.

[0013] Nevertheless, the use of soldier fly larvae is not without problems such as issues related to the breeding of the flies and high energy costs. Moreover, the currently existing plants use ground-based breeding in concrete tanks due to the problems linked to the percolate, the high degree of land use and the considerable use of labour required.

[0014] The technical purpose of the invention is therefore to provide a biocell, a plant and a method for treating organic waste which are able to overcome one or more of the drawbacks of the prior art.

[0015] The aim of the invention is therefore to provide a biocell, a plant and a method for treating organic waste which allows a significant reduction in energy and land consumption.

[0016] A further aim of the invention is to provide a biocell, a plant and a method for treating organic waste which allows an improvement in the economics and the safety of the process in such a way as to make the treatment of organic waste economically sustainable both in the management of urban waste and agricultural by-products. [0017] A further aim of the invention is also to provide a biocell, a plant and a method for the treatment of organic waste which allows the production of secondary raw materials such as animal proteins, fuel oils, livestock feed (for example for the fish farming sector), compost and which allow the recovery of CO₂.

[0018] The technical purpose indicated and the aims specified are substantially achieved by a biocell, a plant and a method for treating organic waste comprising the technical features described in one or more of the accompanying claims. The dependent claims correspond to possible embodiments of the invention.

[0019] In particular, the technical purpose indicated and the aims specified are substantially achieved by a biocell for the treatment of organic waste comprising a main body defining a containment space for a quantity of organic waste to be treated and comprising a rear wall, a front wall, two side walls, a bottom portion and an upper closing portion of the containment space. The biocell also comprises an upper inlet hole, located in the rear wall, configured for the insertion of soldier fly larvae and a quantity of organic waste to be treated by means of the soldier fly larvae in such a way as to obtain vermicompost, upper outlet holes for the soldier fly larvae located in the rear wall and a lower outlet hole for the vermicompost and excess waste material located in the front wall.

[0020] Moreover, the technical purpose indicated and the aims specified are substantially achieved by a plant for the treatment of organic waste comprising a plurality of biocells arranged in pairs along two horizontal parallel rows and a conveyor belt passing between each pair of biocells. The plurality of cells have the respective front walls facing the conveyor belt in such a way that the lower outlet hole of each biocell discharges the vermicompost and the waste material on the conveyor belt.

[0021] Preferably, each pair of biocells comprises further biocells positioned on top of each other to define different levels of height.

[0022] Moreover, the technical purpose indicated and the aims specified are substantially achieved by a method for the treatment of organic waste comprising the steps of preparing a plurality of soldier fly larvae, preparing a quantity of organic waste, introducing the plurality of larvae and the quantity of organic waste into a respective biocell, disposing of the organic waste inside the biocell using the soldier fly larvae in such a way as to obtain vermicompost, separating the soldier fly larvae from the vermicompost and any waste material, recovering the soldier fly larvae and the vermicompost and any waste material. The disposal step is carried out for a period of between fifteen and twenty days.

[0023] Further features and advantages of the invention are more apparent in the nonlimiting description which follows of a non-exclusive embodiment of a biocell, a plant and a method for treating organic waste. [0024] The description is set out below with reference to the accompanying drawings which are provided solely for purposes of illustration without restricting the scope of the invention and in which:

[0025] - Figure 1 is a perspective view of a biocell according to the invention;

[0026] - Figures 2A-2E are different views of the biocell of Figure 1;

[0027] - Figure 3 is a schematic view of a plant according to the invention.

[0028] With reference to the accompanying drawings, the numeral 1 denotes in its entirety a biocell for the treatment of organic waste which, for simplicity of description, will hereafter be referred to as biocell 1.

[0029] The term "organic waste" means organic refuse, agricultural by-products, livestock sludge, waste from the farming industry, digestate from anaerobic digestion, purification sludges and similar waste.

[0030] The biocell 1 comprises a main body 2 forming a containment space for a quantity of organic waste to be treated.

[0031] The main body 2 comprises a rear wall 2a, a front wall 2b, two side walls 2c, a bottom portion 2e and an upper closing portion 2f of the containment space.

[0032] Preferably, the main body 2 is made of PVC or another suitable plastic material and even more preferably is dark and opaque in colour. In other words, the main body 2 (that is, the biocell 1) is made of dark plastic material.

[0033] Preferably, the upper closing portion 2f comprises a cover configured for hermetically closing the containment space and comprising a plurality of nozzles (not illustrated) for keeping moist the organic waste to be treated. In other words, the biocell 1 is hermetically sealed in the upper closing portion 2f and the nozzles allow both the organic waste to be kept moist and the possibility of recirculating any excess liquid which can accumulate at the base of the biocell 1.

[0034] The main body 2 may have the shape of a rectangular parallelepiped in the upper part whilst the lower part has the shape of a right-angled prism. In the accompanying drawings, the lower part has the shape of an oblique prism.

[0035] The dimensions of the main body 2 can vary depending on the organic waste to be treated and its humidity.

[0036] The biocell 1 also comprises an upper inlet hole 3 located in the rear wall 2a.

[0037] The upper inlet hole is configured for the insertion of soldier fly larvae and of the quantity of organic waste to be treated by means of the soldier fly larvae in such a way as to obtain vermicompost. In other words, in a raised and centred portion of the rear wall 2a there is the upper inlet hole 3 whose function is to feed the biocell 1 with the biomass to be treated.

[0038] The biocell 1 also comprises upper outlet holes 4 for the soldier fly larvae located in the rear wall 2a. As shown in the accompanying drawings, the upper outlet holes 4 are positioned in a raised portion of the rear wall 2a and in a portion close to the side walls 2c. The upper outlet holes 4 are also configured to allow the escape of exhaust air rich in CO₂ and water vapour. Preferably, the upper outlet holes 4 have an articulated joint which conveys downwards the soldier fly larvae and upwards the exhaust air to be moved away.

[0039] Preferably, the upper outlet holes 4 comprise luminous LEDs 5 configured for attracting the soldier fly larvae towards the upper outlet holes 4. In particular, the soldier fly larvae are attracted by the light when ready to pupate. In other words, the luminous LEDs 5 represent the only source of light visible inside the biocell 1 by the soldier fly larvae in such a way that, once the organic waste has been treated after a period of fifteen or twenty days, the larvae are naturally attracted by the light once they are ready to reach the pupal stage.

[0040] Preferably, the biocell 1 comprises a ramp 6 for each of the upper outlet holes 4 which extends in such a way as to connect the bottom portion 2e to the upper outlet holes 4. In this way, the ramps 6 allow the escape of the soldier fly larvae once the organic waste treatment has been performed.

[0041] Preferably, each ramp 6 extends inside and along a respective side wall 2c of the main body 2.

[0042] The larvae will autonomously rise up the ramp 6 at the outlet of which they are collected.

[0043] Preferably, according to an embodiment not illustrated, the luminous LEDs 5 may also be positioned along the ramps 6 in such a way as to more easily attract the soldier fly larvae.

[0044] Preferably, the bottom portion 2e comprises a series of holes 7 for housing nozzles for blowing the air and for discharging percolate. The upper outlet holes 4 are also configured to allow the escape of the air.

[0045] The holes 7 at the base of the biocell 1 are used to blow the air into the biocell 1 itself in such a way that there is a correct quantity of oxygen and there are no pockets of material with anoxic conditions.

[0046] Preferably, the nozzles are configured for dispensing heated or cooled air in order to adjust the internal temperature of the biocell 1 according to the requirements with respect to the time of year or the organic waste contained in the biocell 1.

[0047] The biocell 1 also comprises a lower outlet hole 8 for the vermicompost and any excess waste material (such as, for example, liquid material and the like). The lower outlet hole 8 is located in the front wall 2b. In other words, the lower outlet hole 8 is positioned in a lowered and central portion of the front wall 2b and allows the discharging of the waste material from the organic waste treatment.

[0048] Preferably, the biocell 1 comprises a screw feeder 9 (or other similar device such as a worm screw) configured for moving the vermicompost and excess liquid material from the bottom portion 2e of the main body to the lower outlet hole 8. Preferably, in the rear wall 2a there may be a further hole 8a through which it is possible to actuate the screw feeder 9 (or other similar device). In this way, the screw feeder 9 allows the escape of waste and, if the configuration of the bottom portion 2e is not flat but inclined, the digested material can be easily conveyed, avoiding accumulation.

[0049] Preferably, the biocell 1 comprises a vibrating system configured to vibrate the biocell 1 if there is a residual material contained inside the biocell 1 after the escape of the vermicompost.

[0050] Preferably, the biocell 1 comprises load cells for measuring the residual material.

[0051] Advantageously, the biocell 1 allows the organic waste to be enhanced and treated, at the same time allowing the safe breeding of the soldier fly larvae. The separation between larvae and vermicompost is simple and performed safely by the operators.

[0052] Advantageously, the vermicompost thus obtained is free of material which can putrefy and, in order to avoid anaerobiosis phenomena, the air which is blown inside is conveyed and moved away safely so that it can be filtered (by biofilters) and if necessary used. At the end of the process the larvae are collected and treated whilst the vermicompost is discharged, by means of the screw feeder 9 for maturing, screening, then packaged and sold.

[0053] Advantageously, the soldier fly larvae feed on organic waste, thus allowing an efficient disposal.

[0054] Moreover, cuttings and pruning can enter in the feeding of the larvae after treatment with micro-organisms or enzymes which degrade lignocellulosic substances selected on site or purchased.

[0055] Advantageously, the biocell 1 described above allows the recovery of CO₂ produced during the life of the larvae. The CO₂ is sucked and can be conveyed inside photobioreactors to be used as fertiliser for the production of photoautotrophic microorganisms. Moreover, the CO₂ is removed in order to avoid suffocation of the soldier fly larvae.

[0056] Advantageously, an oil rich in fatty acids and a mix of peptides and amino acids derived from the animal proteins can be obtained from the soldier fly larvae bred in the biocells 1. These substances can be used to produce biofuels and biolubricating agents. Alternatively, these substances may be used for obtaining biopolymers in companies in the bioplastic and/or similar sectors. If the organic waste is different from agricultural waste or by-products, the pupa can be used as protein feeds in fish farming.

[0057] Advantageously, chitosan and glucosamine are extracted from the waste derived from the insects; these products can be used in the sectors of food supplements, cosmetics and pharmaceuticals. Moreover, the waste of the treated insects can be reused as a feed for the larvae used in the treatment of further organic waste.

[0058] Advantageously, the conditioner derived from the larval excrement may be used in farming as a soil conditioner or for the extraction of nutrient substances for use for crops in photobioreactors.

[0059] The invention also relates to a plant 10 for treating organic waste.

[0060] The plant 10, schematically illustrated in Figure 3, comprises a plurality of biocells 1 as described above. The biocells 1 are positioned in pairs along two horizontal rows. Preferably, the biocells 1 may be positioned on top of each other so as to increase the production capacity of the plant 10. The distance between the biocells 1 is dictated by a metallic structure (not illustrated) which supports them. In other words, each pair of biocells 1 comprises further biocells 1 positioned on top of each other to define different levels of height.

[0061] The plant 10 also comprises a conveyor belt 11 passing between each pair of rows.

[0062] The plurality of biocells 1 has the respective front walls 2b facing the conveyor belt in such a way that the lower outlet hole 8 of each biocell 1 discharges the ver- micompost and the liquid material on the conveyor belt 11. Preferably, if the biocells 1 are located on top of one another, there is an extension of the lower outlet hole 8 for the upper biocells 1 which lies at a short distance from the conveyor belt 11. This extension advantageously makes it possible to prevent splashing or the raising of dust from the conveyor belt 11.

[0063] The invention also comprises providing a method for treating organic waste. The method is carried out in a biocell 1 or a plant 10 as described above.

[0064] The method comprises preparing a plurality of soldier fly larvae, preparing a quantity of organic waste and introducing the soldier fly larvae and the quantity of organic waste into a respective biocell 1. More specifically, the method comprises introducing the larvae and the organic waste through the upper inlet hole 3.

[0065] The method comprises disposing of the organic waste inside the biocell 1 (or each biocell 1 if there is more than one, such as, for example, in the plant 10) using the soldier fly larvae in such a way as to obtain vermicompost. This step occurs for a period which varies from fifteen to twenty days in which the soldier fly larvae feed on the organic waste, thus generating vermicompost. Moreover, other waste material such as the liquid material is produced during this step.

[0066] This is followed by a step of separating the soldier fly larvae from the vermicompost (and the rest of the waste). This separating step occurs with the escape of the larvae from the upper outlet holes 4, preferably with the rising of the larvae by means of the ramps 6 when attracted by the luminous LEDs 5.

[0067] This is followed by a step of recovering the soldier fly larvae from the upper outlet holes 4 and the vermicompost and any waste material from the lower outlet hole 8 (that is to say, using the conveyor belt 11 if the method is carried out in a plant 10 as described above).

[0068] Preferably, the method may also comprise the steps of introducing air inside the containment space. The step may be carried out by blowing heated or cooled air for discharging any percolate and the temperature adjustment. This is followed by a step for recovering exhaust air from the containment space, using the upper outlet holes 4. The CO₂ and the water vapour recovered in this way can be used as fertiliser for the production of photoautotrophic micro-organisms.

[0069] Advantageously, the invention is able to overcome the drawbacks of the prior art.

[0070] Advantageously, the invention allows a fast treatment and a complete exploitation of the organic waste since the process takes place in fifteen or twenty days.

[0071] Advantageously, the invention makes it possible to breed insects (Hermetia illucens) which are not pathogenic and which are included in the European regulation defining “novel food” and which, depending on the origin of the organic material, can be used to produce biofuel and proteins for the plastic industry, or animal feed, up to food for human consumption.

[0072] Advantageously, the invention allows the organic waste to be treated locally in the company, avoiding costly expenses for transport and disposal with the production of compost and secondary raw materials (such as the larvae).

[0073] Advantageously, the invention allows the treatment of the organic waste avoiding the production of percolate, unpleasant odours and achieving savings on transport and delivery of the waste.

[0074] Advantageously, the use of biocells 1 allows the treatment process to be modulated on the basis of the quantity of organic waste to be treated.

[0075] Advantageously, the production of biofuels and bioplastics makes it possible to move away from the use of raw materials from fossil sources.

Claims

[Claim 1] A biocell (1) for treating organic waste comprising:

- a main body (2) defining a containment space for a quantity of organic waste to be treated and comprising a rear wall (2a), a front wall (2b), two side walls (2c), a bottom portion (2e) and an upper closing portion (2f) of the containment space;

- an upper inlet hole (3), located in said rear wall (2a), configured for the insertion of soldier fly larvae and of said quantity of organic waste to be treated by means of said soldier fly larvae in such a way as to obtain vermicompost;

- upper outlet holes (4) for said soldier fly larvae located in said rear wall (2a);

- a lower outlet hole (8) for said vermicompost and any excess waste material located in said front wall (2b).

[Claim 2] The biocell (1) according to claim 1, comprising a screw feeder (9) configured for moving the vermicompost and excess waste material from said bottom portion (2e) of the main body to said lower outlet hole (8).

[Claim 3] The biocell (1) according to claim 1 or 2, comprising a ramp (6) for each of said upper outlet holes (4) extending in such a way as to connect said bottom portion (2e) to said upper outlet holes (4) in such a way as to allow the escape of said soldier fly larvae once the organic waste treatment has been performed, preferably each ramp (6) extending inside said containment space along a respective side wall (2c) of the main body (2).

[Claim 4] The biocell (1) according to claim 3, wherein said upper outlet holes (4) comprise luminous LEDs (5) configured for attracting said soldier fly larvae towards said upper outlet holes (4).

[Claim 5] The biocell (1) according to any one of the preceding claims, wherein said bottom portion (2e) comprises a series of holes (7) for housing air blowing nozzles and for discharging percolate and wherein said upper outlet holes (4) are also configured to allow the outlet of the air, preferably said nozzles (7) being configured for dispensing heated or cooled air.

[Claim 6] The biocell (1) according to any one of the preceding claims, wherein said upper closing portion (2f) comprises a cover configured for hermetically closing said containment space and comprising a plurality of nozzles for keeping moist said organic waste to be treated.

[Claim 7] The biocell (1) according to any one of the preceding claims, comprising a vibrating system configured to vibrate the biocell (1) if there is a residual material in the biocell (1), preferably the biocell (1) comprising load cells for measuring said residual material.

[Claim 8] The biocell (1) according to any one of the preceding claims, wherein said main body (2) is made of PVC or other plastic materials, preferably dark and opaque.

[Claim 9] A plant (10) for treating organic waste comprising a plurality of biocells (1), according to any one of the preceding claims, arranged in pairs along two parallel horizontal rows and a conveyor belt (11) passing between said pairs of biocells (1), said plurality of biocells (1) having the respective front walls (2b) facing said conveyor belt (11) in such a way that the lower outlet hole (8) of each biocell (1) discharges said vermicompost and waste material on the conveyor belt (11), preferably each pair of biocells (1) comprising further biocells (1) positioned on top of each other and defining different levels of height.

[Claim 10] A method for treating organic waste, in a biocell (1) according to any one of claims 1 to 8 or in a plant (10) according to claim 9, comprising the steps of:

- preparing a plurality of soldier fly larvae;

- - preparing: a quantity of organic waste;

- introducing said plurality of larvae and sad quantity of organic waste into a respective biocell (1);

- disposing inside said biocell said organic waste using the soldier fly larvae in such a way as to obtain vermicompost, said disposal step being carried out in a period of between fifteen and twenty days;

- separating said soldier fly larvae from said vermicompost and any waste material;

- recovering said soldier fly larvae and said vermicompost and any waste material.

[Claim 11] The method according to claim 10, also comprising the steps of:

- introducing air into said containment space, preferably heated or cooled air;

- expelling exhaust air from said containment space.