Process and system for converting solid municipal waste by depolymerisation and transient multi-step reactions

Abstract

The invention relates to a method and system for treating and recovering municipal waste, by means of steps of pre-treatment, degassing, depolymerisation and / or pyrogasification. The process allows synthesis gas, oil and charcoal or biochar to be obtained, which are cooled, cleaned and reused as fuels in the same system. If chlorine compounds are detected, a preliminary degasification step is activated to remove pollutants. The system comprises specific degasification devices with thermal and oxygen control, as well as a reactor that allows multiple passes of the material to ensure the complete processing thereof. Also included is a circuit for collection and separation of liquid, solid and gas products, maximising energy efficiency and the recovery of recoverable by-products. The plant can process different types of waste, including slurry, and is designed to operate safely, autonomously and sustainably.

Description

[0001] PROCESS AND SYSTEM FOR TRANSFORMING URBAN WASTE BY DEPOLYMERIZATION AND / OR PYROGASIFICATION AND TRANSIENT MULTI-STAGE REACTIONS

[0002] DESCRIPTION

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention is related to a procedure and system for the treatment of waste from various sectors, both of industrial origin, as well as urban solid waste (USW), pruning, and sludge and other organic waste, the process incorporates multiple phases and transitional stages that allow the transformation of the material, where the process is made up of a series of equipment, devices or machines intended for the transformation and treatment of multiple materials from recycled material, pre-conditioned to a specific size in each case, being able to obtain, without leaving any type of residue, different types of products and by-products such as the recovery of some types of plastics, ferrous and non-ferrous metals and glass and other products, as well as thermal and / or electrical energy, coal, fuel oil (fuels), diesel (diesel), gasoline, paraffin, among others,being able to take advantage of part of the thermal energy generated for the dehydration of organic materials, as well as the vaporization of products and waste with high water or moisture content, being able to dehydrate organic materials with high moisture content and degas plastic products with contaminant contents, being able to separate these from the solids and sludge with which they are diluted or mixed, passing these gases once clean, to the process burners.

[0005] TECHNICAL FIELD OF THE INVENTION

[0006] The management and treatment of municipal solid waste (MSW) is critical today, as its production is inevitable in any society and increases proportionally with demographics and exponentially with the standard of living. At the social level, a recycling culture has gradually been established, in which each individual is responsible for separating waste according to its type. This has led to a certain degree of facilitation of waste classification in waste treatment plants. However, this waste must be treated to reuse the materials from which it is made and minimize environmental pollution.

[0007] One of the processes regularly applied to minimize pollution involves, once waste has been classified according to its materials, reducing its volume and then transporting it to be incinerated (when it is composed of combustible materials).

[0008] Regarding the latter, there are well-known waste treatment processes that separate, crush, wash, and dry waste, offering an outlet for all reusable materials. Non-reusable materials must be disposed of in landfills, which can generate harmful or even dangerous products.

[0009] Therefore, state-of-the-art processes have been implemented to treat some of the non-reusable products and thus reduce or avoid the harmful products generated.

[0010] These processes can process aluminum or copper compounds, among others, without leaving any residue. They transform the plastic through a chemical reaction into different types of byproducts such as carbon and energy, as well as recover the aluminum or copper for a second life.

[0011] Although all products are expected to be treated for their reuse and to avoid the emission of polluting waste, improvements are still needed in this type of procedure and the associated equipment to be able to treat absolutely all urban waste without leaving any residue. GENERAL DESCRIPTION

[0012] The present invention provides a method and system for the treatment of materials from waste, in particular urban solid waste (MSW) by chemical reaction of the plastics and organic materials contained in said waste for the revaluation and obtaining of fuel, the materials that preferably come from recycled materials such as, but not limited to, plastic products, CDR, CSR, organic materials of carbon origin, plant pruning, slurry from pigs or cattle, chicken manure, as well as aluminum complexes, plastics mixed with aluminum crushed to a specific size, where this system through a series of operatively interrelated devices carries out the degradation of the material by depolymerization in an efficient manner, without leaving residues, and being autonomous by being able to function in normal operation with the fuel that is recovered from the material.Another type of waste that is expected to be treated with the method and system of the invention is industrial waste.

[0013] The method for the treatment of materials from urban waste by means of and their re-valorization comprises the steps of: pretreating the waste to obtain a treatable material, that is, a material suitable for being treated; depolymerizing the material by heating it under oxygen-free conditions, obtaining synthesis gas, oil and solid products containing coal and / or biochar; cooling and storing the coal and / or biochar; cleaning the gas, removing dust from it, obtaining finished gas; distilling the oil to obtain finished oil; directing at least a part of the finished gas to heating in the depolymerization stage and / or to the oil distillation stage, where at least a part of the combustion gases from the depolymerization stage are sent to the stage of degassing the treatable material;where, if the presence of a predetermined product is detected in the material, prior to the stage of depolymerizing the material, a degassing stage is carried out to clean the material of such predetermined product by: heating the material so that it releases gases, where the predetermined product is found in said gases; collecting and cleaning the gases; and directing the cleaned gases for use as fuel in the depolymerization stage.

[0014] In the context of the invention, cleaning the gases prior to the step of depolymerizing the material must be interpreted as cleaning the treatable material when said material contains at least a fraction of chlorinated-based polymers, removing / withdrawing / cleaning the chlorine present in them.

[0015] Therefore, in a preferred embodiment of the method, the predetermined product to be detected comprises the aforementioned chlorinated base polymers, such that the material is heated to a temperature sufficient to release gases within which Chlorine or chlorinated compounds are present, cleaning or removing the Chlorine from said gases.

[0016] A key advantage of removing chlorine from the material at an earlier stage, before depolymerizing it, is that it largely prevents the generation of dioxins and furans when the material degrades during depolymerization. Dioxins and furans are known to be highly toxic and their reactions difficult to control.

[0017] Therefore, the method provides a stage for releasing contaminants present in the treatable material through degassing. This allows for the inclusion of PVC or CPE fractions, among other chlorinated-based polymers, within the materials to be treated. These fractions, which until now had to be separated from the waste and treated independently, are now included.

[0018] Alternatively, in the degassing stage, the material is maintained at a temperature of around 20°C and subsequently heated to a temperature of approximately 290°C. Alternatively, the stage of pretreating the waste to obtain treatable material comprises a series of preliminary stages, including: classifying the waste to obtain classified material; crushing the classified material to a predetermined size, obtaining crushed material; dehydrating the material, either the classified material and / or the crushed material, obtaining the treatable material.

[0019] With respect to dehydration of the material, a chemical product prepared for this process can be used. In this regard, the aforementioned chemical product can be applied to the material either before or after crushing to dehydrate it (eliminate moisture) and simultaneously disinfect it. In a preferred embodiment, the step of dehydrating the material also includes disinfecting said material by applying calcium carbonate (quicklime). That is, taking advantage of the high humidity of urban waste, particularly waste containing organic matter, calcium carbonate is applied without adding water or applying heat.

[0020] Alternatively, in the step of depolymerizing the material, said material is heated to a temperature of about 500°C, preferably about 450°C, more preferably 390°C.

[0021] Preferably, the step of distilling oil to obtain finished oil comprises the sub-step of heating the oil generated in the depolymerization step, where the heating is carried out by electrical induction and / or by burning the synthesis gas and / or by burning the finished oil.

[0022] Alternatively, the flue gases from the depolymerization and / or degassing stage are directed to a flue gas cleaning sub-stage in which the light oil is condensed and the cleaned gases are reused for re-entry into heating in other stages. In another alternative embodiment, the urban waste to be treated comprises slurry or similar, such that the stage of pretreating the waste to obtain treatable material, the slurry is treated according to the following sub-stages: separating the slurry into a solid portion and a liquid portion; selectively, and depending on the size, sending the solid portion to the stage of crushing the material or to the degassing stage or to the depolymerization stage; and purifying the liquids for subsequent disposal.

[0023] In another embodiment, the invention provides a system for the treatment of urban waste by depolymerization and obtaining fuel comprising a degassing device intended for receiving the treatable material and transporting it between an inlet and an outlet of said device, selectively forming at least one plug of material to prevent oxygen from entering the system, and a depolymerization assembly intended for receiving the material from the degassing device and depolymerizing and / or pyrogasifying said material as it is transported between an inlet and an outlet of said depolymerization assembly to obtain gas and coal.

[0024] In the context of the invention, depolymerization is understood as the degradation of polymers, while pyrogasification is understood as the chemical reaction of organic products to compose polymers, where this chemical reaction occurs due to the combination of factors such as temperature, the introduction of water / humidity and Nitrogen.

[0025] It is important to highlight that the treatable material is obtained by passing the waste through previous devices, in which said waste is classified, dehydrated and disinfected by, for example, the application of calcium carbonate (quicklime) and crushed in devices to give it the ideal size to be treated, obtaining a treatable material, that is, a material of adequate size, dry (dehydrated) and disinfected.On the other hand, in particular, the degassing device comprises a first tunnel provided with heating means configured to heat the material; a conveyor that runs through the heating furnace configured to receive and regulate the material, as well as to move it at a controlled speed through the first tunnel and form a plug of material at the exit of said first furnace, a gas cleaning device configured to receive the gases produced by heating the material inside the first tunnel and configured to clean them, and control means configured to control the heating means, the conveyor and the gas cleaner.

[0026] The control means are further configured to, upon an activation signal, activate the heating means to heat the material such that gases are released from said material; and activate the gas cleaning device to clean the released gases.

[0027] As mentioned for the method, in the case of the system the activation signal corresponds to the detection of the presence of chlorine-based polymers in the material, where the device for cleaning the gases cleans the Chlorine from said gases.

[0028] In addition to the advantages associated with not generating dioxins or furans, being able to clean chlorine from the material through degassing with the device protects the system from corrosion caused by the possible formation of chlorinated compounds and prevents explosions.

[0029] In an alternative embodiment, the degassing device comprises a cooler configured to maintain the material at a cold temperature, i.e., a temperature at which the material remains solid and does not release gases, such that the material forms a first cold plug in a first section of said cooler and a second cold plug in a second section of the cooler; where the plugs prevent the entry of oxygen into the system. The first section of the cooler is arranged outside the first tunnel, while the second section is arranged inside the first tunnel, where the conveyor also runs through the cooler. The cooler has the function of, even though the heating means of the first tunnel are active, keeping the material cold, forming the first cold plug between the material feed and the first tunnel, and a second cold plug inside the first tunnel.A third plug is made at the exit of the first tunnel and the entrance to the depolymerization assembly.

[0030] In a particular embodiment, the cooler maintains a material temperature of around 20°C.

[0031] Following the cooler, on the conveyor, inside the first oven and at the activation signal, the material is heated to around 290°C, preferably 230°C, for degassing.

[0032] Optionally, the degasser can also be used to dehydrate the treatable material.

[0033] Furthermore, the system is provided with a safety device located between the outlet of the degassing device and the inlet of the depolymerization assembly. This safety device is configured to detect the start of a fire in the material or an excess temperature in the material and extinguish the fire or reduce the temperature. In this regard, the safety device is configured to inject liquid nitrogen to perform the described functions.

[0034] The system also has a mixer configured to stir and / or compact the material to be treated prior to its placement in the degassing device, forming an additional plug at the inlet of the dehydration device to prevent air from entering.

[0035] On the other hand, the depolymerization / pyrogasification assembly comprises a main furnace which houses a reactor inside, where the main furnace is provided with heating means prepared to heat the reactor to a required temperature and a combustion gas outlet which is connected to the heating means of the first tunnel, such that said first tunnel is heated by the combustion gases of the main furnace; in turn, the reactor is configured to receive the material coming from the degassing device and to depolymerize and / or pyrogasify it, moving it between an inlet and an outlet of said reactor.Furthermore, the depolymerization / pyrogasification assembly comprises detection means configured to detect the state of the material at the reactor outlet such that, if the material is not completely depolymerized and / or pyrogasified, burned or degraded, the reactor is configured to pass the material through said reactor at least two more times.

[0036] The system also includes a silo and extractor hood configured to collect coal or slag and capture gases and / or oil produced by the depolymerization of the material in the reactor.

[0037] According to the above, the silo and extractor hood comprise a compartment in which the coal or slag is deposited, which is transported by a series of conveyors that in between have at least one intermediate storage silo in which the coal or slag accumulates, forming a plug to prevent the entry of air, up to an outlet through which the cold coal or slag comes out.

[0038] Furthermore, the silo and extractor hood is configured to separate and extract gaseous or fluid products (in the form of gas) produced by the depolymerization and / or pyrogasification inside the reactor and comprises at least one gas and oil passage tube through which the gaseous product circulates to a ripple compensator which, in turn, communicates with a sediment tank, intended for the collection of sediments such as oil and volatile fine carbon particles, and then the product continues its journey to fall into a heavy oil tank which will also receive the oils from the gas from the vertical connection tube with a condenser and communicated with a vertical tank where the oil and water contained in the elements to be cooled will be separated, communicated directly with the tank where, by decantation, the heavy and light depolymerized oils are separated as well as the water and the latter gas,It will pass through a gas safety tank filled with water, from where all the gas produced in the treatment of waste or treated materials will be distributed, and from where it will be distributed to all the elements that need it, such as the main furnace that heats the reactor.

[0039] Furthermore, the system of the invention comprises a computerized means for managing and controlling all subsystems involved in waste treatment. This computerized means may be, for example, a computer, a computer network, a server, among others, provided with an executable programmable algorithm through which all variables can be programmed, controlled, and managed, such as, for example, drying temperature, degassing temperature, activation of the degassing section, pressures inside the reactor, speed of movement of the conveyor belts, etc. In this sense, the control means of the degassing device are part of this computerized means.

[0040] On the other hand, there is also a treatment plant or facility for the treatment of recycled materials, originating for example from urban solid waste (MSW) and other materials such as, for example, industrial waste and / or waste similar to urban waste, where this facility includes the system for the treatment of materials by depolymerization and obtaining fuel as described so far.

[0041] BRIEF DESCRIPTION OF THE FIGURES

[0042] The above and other advantages and characteristics will be more fully understood from the following detailed description of some embodiments with reference to the attached drawings, which should be considered as illustrative and not limiting, in which:

[0043] Fig. 1 is a general diagram of the solid waste treatment procedure, showing its different stages.

[0044] Fig. 2 is a general view of the distribution of the method and system of the invention from the entry of the waste or material to be treated until the entry into depolymerization, showing the different devices that are part of this stage.

[0045] Fig. 3 is a plan view showing a part of the system of the invention in which both the degasser and the depolymerization / pyrogasification assembly can be seen.

[0046] Fig. 4 is an elevation view showing a part of the system of the invention in which both the degasser and the depolymerization / pyrogasification assembly can be seen.

[0047] Fig. 5 is a general view of the degasser's gas cleaner. - Fig. 6 is a sectional view of the degasser, showing the temperature profile at which the material is heated inside the degasser to heat the material.

[0048] Fig. 7 is an overview of the gas cleaning subsystem.

[0049] Fig. 8 is a general view of the distillation subsystem. - Fig. 9 and Fig. 10 are views of the slurry treatment subsystem.

[0050] Fig. 11 is a view of the gas cleaning and condensation subsystem with oil remaining from the distillation assembly.

[0051] DETAILED DESCRIPTION OF AN EXAMPLE OF EMPLOYMENT

[0052] In the following detailed description, numerous specific details are presented in the form of examples to provide a thorough understanding of the relevant teachings. However, it will be apparent to those skilled in the art that the present teachings can be implemented without such details.

[0053] As can be seen in the figures accompanying the description, the present invention provides a method and system for the treatment of urban waste by means of depolymerization treatment with the objective of producing renewable solid fuel (SRF) and bio-cellulose fuel (RCF), recovery of metals, glass and heat generation and utilization of gas and diesel, etc. The treatment method is developed mainly two lines of the system, on the one hand, an organic waste separation treatment line, hereinafter referred to as the SRF line, and, on the other hand, a separation line for plastics, metals, paper, glass, etc., hereinafter referred to as the RDF line, in order to make good integral use of the waste, also those from sanitary landfills (dumps). Another intended objective is also to extend the useful life of sanitary landfills, since the method and system are also intended to operate in a sanitary landfill.Therefore, in the case of municipalities wishing to incorporate it, customized facilities could be built for each municipality or association of municipalities. Implementing the present invention also prevents the production of leachate in both cases. Another objective is to also treat industrial waste. Therefore, the proposed invention makes it possible to treat various types of waste for their utilization and revaluation.

[0054] Figure 1 illustrates the method stages, where, as indicated in previous lines, the treatment method runs through two main lines: a CDR line and a SRF line, in addition to an auxiliary CDR line where bulky items such as tires, etc. are treated. The method begins with the entry of the waste into the tank 1, from which, subsequently said waste or material to be treated passes through an input conveyor belt 2, for example, of the type sunk into the ground, to transfer the waste to a mechanical separation station 3, for example, of the manual type, where bulky items, glass, scrap, and pruning will be deposited in containers 3C, 3D, 3E, 3F arranged in said station 3, the rest passing to a trommel / screener 8 with different waste separation sieves. For example, the trommel / screener 8 may have a screening size of approximately 70 mm, which separates the flow into two sizes.The fraction smaller than 70 mm, which generally has a high percentage of fermentable fraction, is called the trommel overflow fraction. The fraction larger than 70 mm, which normally has a majority composition of inert and combustible fractions, is called the trommel overflow fraction. Those skilled in the art will see that the 70 mm sieve or screening size is exemplary, and other sieve sizes are within the scope of the application.

[0055] The trommel sinking fraction will fall onto a sinking belt 9, while the trommel overflow fraction falls onto an overflow belt that is part of an overflow station 6 where, manually on one side and mechanically and / or electronically, optically or laser on the other 7, plastics of different polymers are separated. In this overflow station 6, several containers 6A, 6B, 6C, 6D, 6E, 6F are arranged for the deposit of the separated composite materials. The rest of the material is directed from the overflow station 6 to a crusher, where the necessary granulometric for this type of material is achieved, approximately 30 mm. This crushing process will be discussed in detail later.

[0056] Once the material has been crushed, or even before passing through the mechanical separation station 3, it is directed to a dryer 7A configured to dry the material, reducing its moisture content to 7%. This dryer 7A is also configured to disinfect the material. It is designed as an autoclave, so that the material exiting said dryer 7A is disinfected. Calcium carbonate (quicklime) can be applied in this section to simultaneously dry and disinfect the material.Once dried, disinfected, and ground, the material is considered suitable for treatment, treatable material, and this material is directed to a degassing device 40, hereinafter referred to as degasser 40, which is configured both to move said material and to clean it of chlorine-based contaminants present in the material, such as PVC, CPE, among others, by cleaning the evaporation gases produced by heating said material in the degasser in the presence of PVC or CPE in the treatable material. More detail will be given regarding this degasser 4 later.

[0057] On the other hand, returning to Fig. 2, the sunken trommel passes through the CSR line to which the waste from the bulky pruning is also directed through a conveyor 1B, from which the pruning material is directed to a brush cutter 2B, from which it would be mixed through a belt 3B in which the sunken trommel falls from a trommel 8, where this mixture of material is directed to a second dryer 4B, with identical or similar characteristics to the dryer 7A, described for the CDR line, in which it is dried, disinfected and the humidity is reduced below 38%, this partially dried material being directed to a conveyor 9B where the material will pass through an overband 10B (overband) which separates all the ferrous metals contained in the dried material and deposits them in a container 11B, passing the rest of the material to a conveyor 12B in which it is separate the non-combustible unsuitable waste in a container 13B,continuing along another conveyor 14B, in which non-combustible unsuitable materials continue to be separated in a container 15B, to subsequently pass through a crusher 16B where the material is crushed to a uniform size and subsequently directed to the degasser 40 and subsequent processing, to obtain biofuels.

[0058] On the other hand, there is a bulky line in which materials such as vehicle tires are treated, which are deposited on a conveyor 1A that directs them to a crusher 2A, where the crushed materials are passed through a conveyor with an overband 3A, where the metals are directed to a tank 4A, and the remaining materials can either pass to tanks 5A and 6A from which they are directed to the depolymerizer 5, or directly directed to said depolymerizer 50, or can even be sent to the degasser 40. It is highlighted, as can be seen so far, that the entire treatment of the material is carried out continuously, so that the output of each device is connected or is coincident, or is operatively or fluidically connected with the input of the next device.

[0059] Now, as can be seen in figure 2, once crushed in the crusher 7 and / or dried in the dryer 7A, and / or in the crusher 16, as can be seen in figures 3 and 4, the treatable material moves through a loading belt 2 towards a hopper 3, where a beater / agitator has been arranged to stir and compact the material delivered to the hopper 3, forming a plug to prevent the entry of air and, at the same time, facilitate its dispensing.

[0060] In this sense, the outlet of the hopper 3 coincides with the inlet of the aforementioned degasser 40, which is arranged to receive the material dispensed by the hopper 3 and make it pass through it, forming three plugs of material distributed along the extension of the degasser 40, where said plugs are provided to block the entry of oxygen into the system.

[0061] Likewise, as its name indicates, the degasser 40 is configured to clean the material by degassing when it contains traces or fractions of chlorinated-based products, such as chlorinated-based polymers like PVC or CPE. Thus, upon detecting the presence of PVC or CPE in the material, the degasser 4 is configured to heat the material to a temperature such that it releases gases containing chlorinated compounds and clean or free them of chlorine.The degassing device 40 comprises a first tunnel 40A, provided with heating means (not shown) configured for heating the interior of said oven 40A, through the interior of which runs a conveyor 40B configured to receive the material at the inlet and transport it to the exit of the first tunnel 40A and arranged to regulate the quantity of material to be introduced into the next device, as well as to move the material through the interior of the first tunnel 40A at an adjustable speed, such that, by the combination of displacement and heating temperature, the material is heated and begins to release gases as it moves between the inlet and the outlet of the degasser 4.

[0062] The latter is provided with means for measuring the gas pressure inside the first tunnel. a and temperature detection means for measuring the temperature inside said oven 40 aand / or the material as it is transported by conveyor 40B.

[0063] The conveyor 40B is, in the preferred embodiment, a conical worm screw whose root diameter increases in the direction of advance of the material, being rotatably driven by a motor or similar, so that the material, when accumulating towards the final portion of the route in the conveyor 40B, acts as a plug to prevent the entry of air into the degassing device 40 and treat the materials in the absence of oxygen.

[0064] The degasser 40 comprises a gas cleaning device 40C, hereinafter referred to as "cleaner 40C," configured to receive the gases produced by heating the material inside the first tunnel 40A and to clean them, by means of which, in a controlled manner, the steam or gases generated when heating the material are extracted and cleaned. The cleaner 40C may be incorporated into the degasser 40 itself or as an annex thereto, in fluid communication with, but outside of, the latter.

[0065] The main function of the degasser 40 is to clean the material of the chlorine present in chlorinated-based polymers, if the presence of such polymers is detected in said material, by heating the material, degassing it, and cleaning the gases. Thus, in the degasser 4, for the treatment of the gases produced by heating, not only the gases or vapors produced by the dehydration of the material are collected, but also the gases produced by the plastic mixed with the material, including PVC or CPE which, as is known to the inventor based on current regulations, the mixture of plastics for this type of material recovery procedures only allows up to a maximum of 0.04% PVC content by weight in the content of the mixture. Thus, thanks to the degasser 4 of the invention, the PVC content in the plastic mixture can reach up to 50% by weight of the mixture.Furthermore, it is also possible to operate at low temperatures, cleaning the gases with a chemical and water. When the gases pass through the 40C cleaner, they are cleaned, avoiding emissions of chlorine, dioxins, sulfur, and other chemicals that are produced inside the degasser 4 at low temperatures. These gases can be reused by burning them in the furnace to heat the reactor of the depolymerization assembly 50 60.

[0066] As can be seen in Figure 5, the cleaner 40C is comprised of a sight glass 41C, a tank 42C in which the cleaning chemical product is deposited, an inlet for adding water 43C, a gas outlet 44C, a liquid striation 45C, a tank 46C in which the water and the cleaning chemical product are mixed, a limiter / indicator 47C of the chemical-water mixture level, a pump 48C for extracting the gas and sending it to the depolymerizer 50, an outlet duct 49C through which the gases exit heading to the depolymerizer 50, a valve 410 for adding and regulating as well as closing the gas outlet and a tank 411C of material for treatment. In cleaner 40C the gases are passed through the liquid water-chemical mixture in tank 46C, such that the dirt remains in the liquid mixture and the gases are cleaned and directed to depolymerizer 50 for use as fuel.

[0067] Likewise, the degasser 40 comprises a cooler provided with a first section arranged outside the first tunnel 40A and a second section arranged inside the first tunnel 40AA, where the conveyor 40B also runs through said cooler, said cooler being configured to maintain the material at a cold temperature, such that the material forms a first cold plug in the first section and a second cold plug in the second section of the cooler; where the plugs prevent the entry of oxygen into the system.

[0068] Although the heating means of the first tunnel 40A are active for degassing, the cooler has the function of keeping the material cold to form the first cold plug between the material feed from the hopper 3 and the first tunnel 40A, and a second cold plug inside the first tunnel 40A. As previously mentioned, a material plug, the third plug, is made at the exit of the first tunnel 40A and the entrance of the depolymerization assembly 50 60.

[0069] Thus, the cooler maintains the material as it passes through at a temperature of around 20°C, conveniently injecting liquid nitrogen.

[0070] To form the plugs, the material accumulates between the propeller and shaft of the conveyor 40B together with the internal walls of the first tunnel 40A. Specifically, in the second section of the cooler, the conveyor 40B does not have a propeller, so the material moves by accumulation and push of the material itself coming from the first section. When sufficient material accumulates in this part, it is caught by the propeller or blade of the conveyor 40B that continues downstream of the degasser 40, for transport, heating and degassing if required, and moving it to its subsequent disposal.

[0071] On the other hand, the degasser 40 also has a valve / regulator operatively connected to the first tunnel 40A and to a combustion gas outlet of the first tunnel 40A, said valve being configured to regulate the flow of combustion gases by opening or closing the passage of the same to achieve the desired heating / degassing temperature in the first tunnel 40A, depending on the material to be treated.

[0072] A safety device (not illustrated) has also been arranged at the outlet of the degasser 40, which is designed to extinguish the fire if it occurs and a possible excess of temperature in the material, the safety device being based on an injected CO2 fire extinguisher or, failing that, Nitrogen, and comprises a control unit configured to detect the start of the fire and / or excess of temperature and activate the fire extinguisher.

[0073] This phase, from the feed to the exit of the degasser 40, is suitable for, when required, heating all the materials to the appropriate temperature, without melting or liquefying them completely, where the gases containing Chlorine are also cleaned, and then moving on to the next phase, which is described in detail later, in which there is a reactor / reactor assembly of larger dimensions and in which the temperatures are much higher and more constant than those of the degasser 4 in which, always depending on the material, the temperature can vary between, for example, preferably 0 o at 290°C, even more preferably from 0°C to 230°C.

[0074] With respect to the temperature profile presented in the degasser 40, at its inlet, and as observed in figure 6, the material to be heated is at a temperature around room temperature and in a first phase while it moves along the conveyor 40B (screw) it is maintained at around 20°C, where by transport, then, in a second phase, the material is maintained within the first section within the tunnel 40A and at a temperature of 20°C to keep it solid and form the plugs. Following this, in a third phase, the temperature of the material is raised from 20°C to 290°C, preferably 230°C, this being the outlet temperature of the material from the degasser 40. It is in this third phase where degassing is carried out.

[0075] Now, the method and system of the invention comprises a depolymerization / pyrogasification assembly 50 60, depolymerizer 50 60 hereinafter, intended to receive the degassed material from the degasser 40 and depolymerize and / or pyrogasify said material as it is transported between an inlet and an outlet of said depolymerizer 50 60 to obtain gas and coal.

[0076] The depolymerizer 50 60 comprises a main furnace 50 that houses a reactor 60 inside. The main furnace 60 is made up of steel walls and refractory cement (or fireproof fiber), and is provided with heating means in the form of one or more gas and diesel burners, which are configured to heat the reactor 60 at high and low temperatures, which, in turn, is separated from the walls of the furnace 50 itself.

[0077] The reactor 60 preferably consists of a hollow cylinder comprising an auger (not illustrated) inside, coinciding in the same horizontal plane with respect to the heating conveyor 40B, said auger being configured to receive and move the material coming from the degasser 4 through its interior at an adjustable speed.

[0078] It is in reactor 60 where the depolymerization of the material takes place, that is, the chemical and gaseous reaction to obtain coal and gas as the material travels from the end of degasser 4 (end of conveyor 40B) to the exit of reactor 60.

[0079] It is important to note that, preferably, between the outlet of the degasser 4, that is to say at the end of the heating conveyor 40B, and the inlet of the depolymerizer 50 60, that is to say at the beginning of the reactor 60 and the main furnace 50, a pre-chamber 60A is arranged in which the material is temporarily stored and accumulated, forming a plug to prevent the entry of gases into the reactor 60. Therefore, the material is taken by the auger from the pre-chamber 60A.

[0080] According to the above, the safety device is operationally connected in this part, so that the start of fire or excess temperature at the inlet of the depolymerizer 50 60 is prevented.

[0081] As mentioned, the safety device is made up of a battery of CO2 or Nitrogen bottles, being provided with control means to control the operation and blow CO2 or Nitrogen, when necessary, where the control means of the safety device will detect, by means of a temperature sensor, when it should be activated according to a previous programming of the same.

[0082] Likewise, at least one Ü2 sensor (not shown) is provided to detect the presence of O2 inside the reactor 60, where given a pre-established quantity of O2 detected by the sensor, it can be evacuated, or the preventive activation of the safety device. In addition, there is at least one temperature sensor, for example, of the laser or infrared type, among others, to detect the temperature inside the reactor and manage its heating.

[0083] The reactor 60 is preferably rotary, that is, the auger is static, while the rotation of the reactor 60 is what generates the displacement of the material. In addition, it has means for inspecting the depolymerized material, configured to detect the state of the material once it has made at least one trip through the reactor 60, such that, if the material has not been completely depolymerized, burned or degraded, the reactor 60 can be reversed, that is, its direction of rotation can be changed, so that the material makes the reverse trip, once again being subjected to the high temperatures coming from the main furnace 50, and then the reactor 60 can be reversed again and the material depolymerized again, taking it towards the outlet of the reactor 60.Therefore, if the material has not degraded sufficiently in a first pass through reactor 60, it is subjected to at least two additional passes through reactor 60 to complete its degradation, this always being controlled by the material inspection means.

[0084] It is important to highlight that, unlike conventional pyrolysis, which usually works in a vacuum, the depolymerizer 50 60 of the invention works “overpressure”, that is, with pressures higher than atmospheric, for example, in a range of 1 to 3 atm.

[0085] In addition, the main furnace 50 has been provided with displays or windows that allow viewing the interior of said furnace 50 and the reactor 60.

[0086] On the other hand, the coal or slag generated by the depolymerization in the depolymerizer 50 60 is moved to a silo and extractor hood 12, operatively linked to the depolymerizer 50 60 and located downstream of the latter, where it accumulates. At this point, a safety device as described above is also provided to control the temperature and operation and to inject CO2 or nitrogen, when necessary, to avoid excessive temperatures and / or excess oxygen into the system. From here, when the compartment where the coal or slag accumulates is full, a first coal conveyor 70, preferably a screw conveyor, moves the coal at the speed and temperature desired at any given time, as needed.It would then pass to a second coal conveyor 80, preferably also a double-screw, which transports the slag to a storage silo 90 also generating a plug, and from this storage silo 90 it is transported by a third conveyor 100, preferably a double-screw, the second 80 and third conveyor 90 being designed with suitable means, for example, a sleeve, so that the cold coal or slag comes out through an outlet 110. In addition, the movements of each of the conveyors 70 80 100 are adjustable in speed according to the demand for coal or slag produced, at the same time, it must be guaranteed that the conveyors 70 80 100 are always full of coal or slag to generate plugs, where said plugs in each of the stages prevent the entry of air into the system.

[0087] On the other hand, in addition to collecting the carbon produced by the depolymerization of the material inside the depolymerizer 50 60, as seen in Figure 3, the silo and extractor hood 12 is configured to extract the gas produced by said depolymerization. The silo-extractor hood assembly 12 also comprises at least one gas and oil passage tube 13 connected to a ripple compensator 14 that communicates with a sediment tank such as oil and volatile fine carbon particles to fall into a heavy oil tank 15 configured to transfer the set of both elements to a tank 16, which will also receive the oils from the gas from the vertical connection tube with a condenser 17 and communicated with a vertical tank where the oil and water contained in the elements to be cooled will be separated, directly communicated with a tank 18 where, by decantation, the heavy and light depolymerization oils as well as the water and gas are separated.The latter will pass through a gas safety tank 20 which is preferably filled with water, from where it will be distributed to all the elements that need it, such as the reactor 60 of the depolymerizer 50 60, the furnace of the distillation reactor 31 and with a double safety valve, one mechanical and the other electric, where the latter will regulate the flow based on the pressure that the system needs at all times.

[0088] Since the gases extracted by the depolymerization are used, in part, to heat the reactor 60 of the depolymerizer 50 60, the combustion gas from the burners of said reactor 60 can be cleaned by passing such gases through a cleaning subsystem which, as can be seen in Figure 6, comprises a tube 1 that is connected to the gas outlet of the depolymerizer 50 60, in particular to the oven 50, the tube 1 is connected to the tank 2, in which it is possible, for example, to heat water and use the steam produced therein, for example, to generate thermal energy by taking advantage of this energy in other points of the system that need it for heating, for example, for drying material, etc.In turn, this tank 2 is also connected to the outlet with tube 3 which connects to a cleaning system 4 designed for sulfur and volatile particles, which is connected to a pump 5 and a closed water circuit 6, which eliminates the dust through the feed tube of pump 5.An outlet tube 7 for these gases leads to the next step 9 which is a water tank, designed to cool and clean with a second cleaning, again the remaining dust that could remain, water tube 8 coming from a dust removal pump 10, where this tank will be connected to a third water tank 11, where the remaining dust will be eliminated by water film; the third water tank 11 is connected to a suction turbine 13, which in turn will be connected to a fourth tank 14 that will collect all the air and gases aspirated will remove force and after this will go a depolymerized oil tank that connected between the outlet 14 and the chimney 15 will heat oil, thus obtaining great energy savings, for the subsequent step, which is distillation.

[0089] On the other hand, as is well known, the oil obtained in the depolymerization must be distilled, therefore, the oil coming from the depolymerization condenser tank 18 (see Fig. 3) is transferred and heated in tank 13 of the distillation subsystem, as seen in Figure 8. It is even possible for the depolymerization condenser tank 18 and tank 13 to be the same tank. Now, the oil contained in tank 13 is preferably at a temperature between 30 -100 ° C and, for its distillation, it is necessary to heat it, which can be carried out in two ways, one by electrical induction 10 and another with fuel, gas and / or diesel, obtained from the oil obtained by the process and burned in burners 12, either gas or diesel.This distillation subsystem is provided with a catalytic tower 14, specifically designed to treat said oil, where the light oil and the gases produced by heating in tank 13 rise through said catalytic tower 14 and the gases are passed through a coil and tube condenser 15 - 16, passing through a safety tank 17 and, subsequently, to a distilled fuel tank 18. It is also directed towards intermediate oil tanks 19 20, to finally pass them through two sedimentation tanks 21-22 where a proprietary additive will be applied, which improves the quality of the oil, then passing to the final product tank 23 and, subsequently, to the storage tank 7 where the finished oils / liquid fuel are stored.

[0090] As mentioned above, the first tunnel 40A is provided with heating means for heating the material as it is transported by the conveyor 40B. Since the system is designed to be efficient and clean, in the preferred embodiment, said heating means come from at least part of the combustion gases used to heat the main furnace 50. In this sense, the main furnace 50 communicates via a duct (through which the combustion gases of said main furnace 50 exit) with the first tunnel 40A to take advantage of the heat of the combustion gases and heat the material placed in the heat carrier for degassing.Therefore, depending on the materials to be treated, the system control means, through sensors arranged for this purpose, detect the temperatures and regulate the entry of combustion gases from the main furnace 50, so that the temperature at which the material is degassed in the degasser 4 is the optimal or required one at all times.

[0091] On the other hand, although the heating means of the depolymerizer 50 60 are fed by the gas produced and recovered from the depolymerizer assembly 5060 itself in their normal operation, the system also has a fuel tank 19, for example, for diesel, to start the reactor 60 in the event of shutdowns for maintenance and other reasons. According to the above, the system comprises one or more pipelines that direct the fuels (gas and fuel oil recovered from the depolymerization) to be used in the heating means of the main furnace 50, that is, towards the burners of said main furnace 50 composed of, but not limited to, two mixed diesel-gas burners and three gas burners, the quantity and power of which may be lower or higher depending on the type and size of the reactor 50, as well as its configuration.

[0092] Additionally, the system includes an air compressor to assist with the initial start-up of the fuel oil mixture for the burners and the butane gas required for the gas burners. This also includes the producer gas, or synthesis gas, which will be initially used after production begins in the main reactor.

[0093] On the other hand, as can be seen in Figure 11, the invention also comprises a final cleaning step and obtaining the remaining oil content in the gas, where said gas comes from the surplus gas, for example, from the consumption of the depolymerization step itself, where said gas is conducted through a tube H3 towards an oil condenser passing to this second double-pass condenser H7, exiting through area H8 passing through tube H9 which will deposit the oils contained therein. The rest of the gas is directed to a tank H10 provided for this purpose, collecting said material through an outlet valve H11. All this supported on an iron and masonry support H13.

[0094] The passage through tube H9 to the second condenser H7 will give the clean gas outlet H12 for subsequent use, where the outlet tube H12 includes a sampling valve H18. An air impeller H4 drives air through H2 and mixes it with a valve H19 that enables the entry of gas, to mix it with the driven air for subsequent burning, with two burners H17, where the gas will be burned inside a furnace H1 designed for this purpose.

[0095] Optionally, an additional subsystem for the treatment of slurry, sewage sludge and organic materials with a high moisture or water load can be added to the method and system of the invention, this subsystem comprising, as seen in Figures 9 and 10, a solids / liquid separator 1, preceded by a solids compactor 2 and an agitator 3 configured to agitate the slurry or similar arranged in a tank 7 or pit, moving said slurry by means of blades 6 connected to said agitator 3, designed with power and size suitable for each case. On the other hand, the subsystem comprises a control panel 4, programmed to control the treatment of the slurry.In tank 7 there is a submerged pump 9 for extracting the slurry which will be pumped towards separator 1, where the separation of liquids and solids takes place, where the liquids will pass to a tank 8 for the purification treatment of the separated water and, on the other hand, the solids that exit through the solids compactor 2, free of moisture, are directed towards the depolymerizer 50 60.

[0096] According to the above, the present invention provides a system for obtaining fuel through the treatment of recycled materials by depolymerization such as, but not limited to, plastic products, CD-R, CSR, organic materials of carbon origin, vegetable manure, slurry from pigs or cattle, poultry, as well as aluminum complexes, plastics mixed with aluminum crushed to a specific size, where the system is provided with a series of transitional stages carried out by different devices through which the material to be treated moves to achieve efficient depolymerization and obtain fuel from such materials, said system being clean, harmless and without producing waste.

[0097] Furthermore, the system of the invention comprises a computerized means for managing and controlling all subsystems involved in the waste treatment method. This computerized means can be, for example, a computer, a computer network, a server, among others, provided with an executable programmable algorithm through which all variables can be programmed, controlled, and managed, such as, for example, drying temperature, degassing temperature, activation of the degassing section, pressures within the reactor, speed of movement of the conveyor belts, etc.

Claims

CLAIMS 1. A method for treating and recovering municipal waste, comprising the steps of: pretreating the waste to obtain treatable material; depolymerizing and / or pyrogasifying the material by heating it to obtain synthesis gas, oil, and solid products containing coal and / or biochar; cooling and storing the coal and / or biochar; cleaning the synthesis gas by removing dust from it to obtain finished synthesis gas; distilling the oil to obtain finished oil; directing at least a portion of the finished synthesis gas to heating in the depolymerization step and / or to the oil distillation step, where at least a portion of the flue gases from the depolymerization and / or pyrogasification step are sent to a material degassing step;where, if the presence of a predetermined product is detected in the material, prior to the stage of depolymerizing the material, the degassing stage is carried out to clean the material of such predetermined product by: heating the material so that it releases gases, where the predetermined product is found in said gases; collecting and cleaning the gases; and directing the clean gases for use as fuel in the depolymerization stage.

2. Method according to claim 1, wherein the predetermined product to be detected comprises chlorinated base polymers, such that the gases released upon heating the material to release gases contain Chlorine, where the gases are cleaned of Chlorine.

3. Method according to any of claims 1 or 2, wherein in the degassing step, the material is heated to approximately 290°C.

4. Method according to any of the preceding claims, wherein the step of distilling oil to obtain finished oil comprises the sub-step of heating the Oil generated in the depolymerization stage, where heating is carried out by electrical and / or electromagnetic induction and / or by burning synthesis gas and / or by burning finished oil.

5. Method according to any of the preceding claims, wherein the combustion gases from the depolymerization and / or degassing stage are directed to a cleaning sub-stage in which the light oil thereof is condensed and the clean gases are reused for re-entry into heating in other stages.

6. A method according to any of the preceding claims, wherein the material to be treated is slurry or similar, such that the step of pretreating the waste to obtain treatable material, the slurry is treated following the following sub-steps: separating the slurry into a solid part and a liquid part; selectively, and depending on the size, sending the solid part to a stage of crushing the material or to the degassing stage or to the depolymerization stage; and purifying the liquids for subsequent disposal.

7. System for treating materials from waste to obtain fuel, comprising: a degassing device (40) intended for receiving treatable material and transporting it between an inlet and an outlet of said degassing device (40) selectively forming at least one plug of material to prevent oxygen from entering the system; and a depolymerization / pyrogasification assembly (50) (60) intended for receiving material from the degassing device (40) and depolymerizing and / or pyrogasifying said material as it is transported between an inlet and an outlet of said depolymerization assembly (50) (60) to obtain gas, oil and coal; where the degassing device (40) comprises a first tunnel (40A) provided with heating means configured to heat the material; a conveyor (40B) running through the first tunnel (40A), configured to receive and regulate the material, as well as to move it at a controlled speed through the first tunnel (40A) and form a plug of material at the exit of the first tunnel (40A); a gas cleaning device (40C) configured to receive the gases produced by the heating of the material inside the first tunnel (40A) and configured to clean them; and control means configured to control the heating means, the conveyor (40B) and the gas cleaner (40C), where, upon an activation signal, the control means are additionally configured to: activate the heating means to heat the material such that gases are released from said material; and activate the device for cleaning the gases (40C) to clean the released gases.

8. System according to claim 7, wherein the activation signal corresponds to the detection of the presence of chlorine-based polymers in the material, where the device for cleaning the gases cleans the Chlorine from said gases.

9. System according to any of claims 7 or 8, wherein the degassing device (40) comprises: a cooler provided with a first section arranged outside the first tunnel (40A) and a second section arranged inside the first tunnel (40A), where the conveyor (40B) also runs through the cooler, said cooler being configured to maintain the material at a cold temperature, such that the material forms a first cold plug in the first section and a second cold plug in the second section of the cooler; where the plugs prevent the entry of oxygen into the system.

10. System according to any of claims 7 to 9 comprising a safety device arranged between the outlet of the degassing device (40) and the inlet of the depolymerization / pyrogasification assembly (50) (60), being said safety device configured to detect the start of a fire in the material or an excess of temperature in the same and extinguish the fire or reduce the temperature.

11. System according to any one of claims 7 to 10, wherein the depolymerization / pyrogasification assembly (50) (60) comprises a main furnace (50) which houses inside a reactor (60), where the main furnace (50) is provided with heating means prepared to heat the reactor (60) to a required temperature and a combustion gas outlet which is connected to the heating means of the first tunnel (40A) such that said first tunnel (40A) is heated by the combustion gases of the main furnace (50); in turn, the reactor (60) is configured to receive the material coming from the degassing device (40) and for depolymerization and / or pyrogasification of said material by moving it between an inlet and an outlet of said reactor (60);where the depolymerization / pyrogasification assembly (50) (60) comprises detection means configured to detect the state of the material at the outlet of the reactor (60) such that, if the material is not completely depolymerized / pyrogasified, the reactor (60) is configured to pass the material at least two more times through said reactor (60).; 12. System according to any of claims 7 to 11 comprising a silo and extractor hood (12) configured to separate and extract gaseous or liquid products and to collect coal or slag, capture gases and / or oil produced by the depolymerization of the material in the reactor (60).

13. System according to the previous claim, where the silo and extractor hood (12) comprises a compartment in which the coal or slag is deposited, which is transported by a series of conveyors (70) (80) (100) with intermediate storage silos (90) in which the coal or slag is accumulated, to an outlet (110) of cold coal or slag.

14. System according to any of claims 12 or 13, comprising, downstream of the silo and extractor hood (12), a gas and oil passage pipe (13) through which the gaseous product circulates to a ripple compensator (14) which, in turn, communicates with a sediment tank (15), designed for the collection of sediments such as oil and volatile fine carbon particles, and then the product continues its journey to fall into a heavy oil tank (16) which will also receive the oils from the gas of the vertical connection pipe with a condenser (17) and communicated with a vertical tank where the oil and water contained in the elements to be cooled will be separated, communicated directly with the tank where, by decantation, the heavy and light depolymerization oils are separated as well as the water and gas (18) the latter will pass through a gas safety tank (20) that is filled with water, from where all the gas produced in the treatment of the waste or treated materials will be distributed, and from where it will be distributed to all the elements that need it, such as the main furnace (5) that heats the reactor (6).

15. Installation for the treatment of recycled materials from urban solid waste in which the method of claims 1 to 6 is implemented, by means of the system of claims 7 to 14.

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