Method for treating heterogeneous solid waste without prior separation

Abstract

The present invention relates to a method for treating heterogeneous solid waste, municipal waste, industrial waste comparable to urban waste, and hospital waste, the method comprising: an initial step A) of continuously introducing waste, without prior separation, into a sealed and pressurised reactor (1) of varying dimensions; a step B) of maintaining the waste in the reactor (1) for 20 to 60 minutes, during which time the following is carried out: a step B1) of injecting water steam, at a pressure between 2 and 12 bar, to maintain a constant and stable temperature between 100°C and 180°C, and a stream of hydroxyl radical (OH), and a step B2) of constantly applying motion and stirring to the waste; and a final step C) of extracting waste, also doing so continuously, once the residence time in the reactor (1) has been exceeded.

Description

[0001] DESCRIPTION

[0002] HETEROGENEOUS SOLID WASTE TREATMENT PROCESS WITHOUT PRIOR SEGREGATION

[0003] OBJECT OF THE INVENTION

[0004] The invention, as expressed in the statement of this specification, relates to a process for treating heterogeneous solid waste without prior segregation, that is, without having to classify or disburse the waste.

[0005] The object of the present invention lies in a technical process specifically intended for the treatment of: a) municipal solid waste, b) industrial waste similar to urban waste, c) hospital waste and d) Tetrapack® type beverage cardboard containers;which allows them to be transformed, without the need for prior segregation (which means that in each of the categories a), b), c) and d) the waste may be mixed, without prior classification, as it is collected at source, although during the process some categories are not mixed with others to preserve traceability from the source), into clean and manageable by-products that can be reused as raw materials, for which the process is based, essentially, on the disinfection and sterilization of the waste and its morphological transformation to facilitate its subsequent classification by means of the combined application of a stream of water vapor and a stream of hydroxyl radical inside a pressurized hermetic reactor into which said waste is introduced.;

[0006] FIELD OF APPLICATION OF THE INVENTION

[0007] The field of application of the present invention falls within the sector of the industry dedicated to the processing and transformation of waste, mainly urban solid waste, waste similar to urban waste and hospital waste.

[0008] BACKGROUND OF THE INVENTION

[0009] Solid waste, specifically municipal waste, industrial waste similar to urban waste, Tetrapack® type beverage cartons and hospital waste, hereinafter "waste", is characterized by a highly heterogeneous composition that includes metallic elements, plastics in all their forms and polymers, pieces of mineral origin such as stones, ceramics, shells, bones, organic compounds such as food scraps, feces, dead animals and other remains of animal origin or cellulose compounds, textile fibers, fibers of plant origin such as paper, cardboard or pruning remains, among others. In addition, the granulometry of the waste can vary from a few tenths of a millimeter to several centimeters.

[0010] Furthermore, from a biochemical point of view, the waste is characterized by its high pathogen content, a term normally used to describe microorganisms such as viruses, bacteria and fungi, among other infectious agents that can cause diseases in humans and animals.

[0011] In turn, mainly due to the presence of organic matter, the average pH of the waste is between 6 and 8, while its humidity is between 40% and 60% (w / w).

[0012] These waste conditions make it difficult not only to sort the waste, but also to reuse the materials obtained. When a plastic or metal container has been in contact with organic elements, it is highly likely to carry traces of those organic components on its walls, which, at room temperature, will proliferate into pathogens as a result of their aerobic decomposition. Therefore, it is not only necessary to properly separate the waste to reuse its constituent materials, but it is also necessary to properly clean and disinfect them.

[0013] Additionally, Tetrapack® type beverage cartons, being multi-layer containers generally made with 75% cardboard, 20% polyethylene plastic and 5% aluminum, are especially difficult to recycle as the polyethylene plastic cannot be easily separated from the aluminum.

[0014] Environmental policies aimed at sorting at source not only fail to take into account the high logistical costs and environmental pollution generated by selective collection, but also fail to address this fundamental aspect of waste cleanup.

[0015] For these reasons, these European directives have already demonstrated a slow and inefficient level of implementation, as well as a certain reluctance on the part of society to carry out segregation work at source.

[0016] The objective of the present invention is, therefore, to provide a practical solution that allows both problems to be resolved in a single waste treatment operation, through a new process that simultaneously concentrates the actions of disinfection of the waste, including Tetrapack® type beverage cartons and their morphological transformation to facilitate their subsequent classification.

[0017] On the other hand, and as a reference to the current state of the art, it should be noted that, at least on the part of the applicant, it is unknown whether any other waste treatment process has been or is being carried out that has technical characteristics equal to or similar to those of the present invention.

[0018] EXPLANATION OF THE INVENTION

[0019] The process for treating heterogeneous solid waste without prior segregation that the invention proposes is configured as the ideal solution to carry out the objective previously stated, with the characterizing details that make it possible and that distinguish it being conveniently included in the final claims that accompany this description.

[0020] Specifically, what the invention proposes, as previously indicated, is a technical process specifically designed for the treatment of municipal solid waste, industrial waste similar to urban waste, hospital waste, and Tetrapack®-type beverage cartons. This process allows them to be transformed, without the need for prior segregation (the different types of waste can be mixed in bags), into clean, manageable byproducts that can be reused as raw materials. To this end, the process takes place inside a sealed, pressurized reactor, the dimensions of which vary depending on its capacity.

[0021] The waste, without prior segregation (the different types of waste can be mixed and inside bags), is introduced into the reactor continuously (this means that the waste does not stop entering from the outside, into the reactor, at a rate of between 1,000 and 10,000 kg per hour, without an airlock process or batch system).

[0022] When the waste enters the reactor, it is already at the process pressure and temperature conditions to ensure immediate thermal shock.

[0023] The residue remains inside the reactor for a period of time ranging from 20 to 60 minutes.

[0024] Preferably through two separate sources, water vapor at a temperature ranging from 100°C to 180°C is injected into the reactor in a controlled manner, on the one hand, and a stream of hydroxyl radicals (OH) is injected into the reactor. The steam input regulation will be determined by the operating setpoint and the pressure expected for the process, which will range between 1 bar and 9 bar absolute.

[0025] The confluence of hydroxyl radicals with water vapor produces a controlled hydroxylation reaction where new water molecules and new hydroxyl radicals are generated. However, the most important aspect is that nano-sized hydroxyl radicals penetrate deep into the waste fibers, destroying and / or inhibiting pathogens.

[0026] Steam is already an important disinfectant agent due to heat transfer; however, its molecular size is 6000 nm, while the hydroxyl radicals contained in water are between 5 and 20 nm in diameter, facilitating their access to the most remote points of the material to be disinfected in the waste.

[0027] Furthermore, while the waste remains inside the reactor, it is subjected to constant movement and agitation, which facilitates its tearing, morphological homogenization, and the access of steam and hydroxyl radicals to all its parts.

[0028] The process that occurs inside the reactor allows, especially at the temperature reached, to separate the different materials that make up Tetrapack® type beverage cartons, even separating polyethylene plastic from aluminum.

[0029] Once the process time has elapsed, the waste is extracted from the reactor, also continuously (this means that the waste continuously leaves the reactor, without the use of locks or batches), going from working pressure to external atmospheric pressure.

[0030] The most significant evidence of the residue at the reactor outlet is the following:

[0031] - A volume reduction of between 20% and 90%.

[0032] - An elimination of pathogens.

[0033] - An elimination of bad odors.

[0034] - A homogenization of organic matter in the form of granular biomass.

[0035] - A densification of plastics that melt at a lower temperature, generally obtaining them in spherical shapes.

[0036] Finally, it should be mentioned that, advantageously, the described procedure is likely to be carried out by using specific transportable equipment, for example transportable modular equipment such as that described in document P202131096, the owner of which is the applicant of the present invention, and which basically comprises a reactor made up of modules that can be dismounted and coupled together, each of which internally incorporates means to develop a specific function that, at least, covers the loading function, process digester, unloading and dehydration, and control and power supply.

[0037] DESCRIPTION OF THE DRAWINGS

[0038] To complement the description being made and in order to help better understand the characteristics of the invention, a drawing is attached to this specification, as an integral part thereof, in which the following has been represented for illustrative and non-limiting purposes:

[0039] Figure 1 shows, in a block diagram, a representation of the flow of steps comprising the process object of the invention; and Figure 2 shows a schematic perspective view of an example of equipment for carrying out the process of the invention.

[0040] PREFERRED EMBODIMENT OF THE INVENTION

[0041] In view of the figures described, and according to the numbering adopted in them, it can be seen how the process of treating heterogeneous solid waste without prior segregation (the different types of waste may be mixed in bags) essentially comprises the following stages:

[0042] - Stage A) initial introduction of the waste to be treated carried out continuously, without prior segregation, inside a hermetic reactor (1), already pressurized and at process temperature, without the use of locks, without the entry of waste in batches;

[0043] - Stage B) of maintaining the residue inside the reactor (1) for a period of time between 20 and 60 minutes, during which the following is carried out:

[0044] - A stage B1) of injection of saturated dry steam at a pressure of between 2 and 12 bar inside the reactor (1), while the residue remains inside the reactor in an atmosphere of stable pressure and a stable temperature, which oscillates between 100°C and 180°C, depending on the characteristics of the residue to be processed, and injection of a stream of hydroxyl radical (OH) at a flow rate that oscillates between 0 and 5000m 3 per minute inside the reactor.

[0045] - And a stage B2) of constant application of movement and agitation to the residue during its stay inside the reactor (1), to facilitate its tearing, morphological homogenization and contact with steam and hydroxyl radicals in all its parts. - Stage C) final extraction of the residue from the reactor (1), once the residence time has passed, in a continuous process, which preferably takes a time of between 1 and 60 seconds, to generate an inverted thermal shock again and without depressurizing or cooling the reactor.

[0046] Preferably, the pressure provided inside the reactor (1), at least during the stages (B1-B2) in which the waste remains in the reactor, ranges between 1 bar and 9 bar absolute.

[0047] Preferably, the injection of water vapor and the hydroxyl radical stream in stage (B1) is carried out through two external differentiated sources.

[0048] Preferably, the introduction of the waste into the equipment occurs continuously without the use of airlocks, without the entry of waste in batches in an operation, which preferably takes a period of time between 1 and 60 seconds, without the need for prior segregation, causing a thermal shock upon entering the interior of the equipment.

[0049] Also preferably, the waste outlet to the outside of the equipment, that is, at atmospheric pressure and temperature, occurs continuously, without interruptions, without the use of airlocks or product batches, and without the need to pressurize or depressurize the equipment.

[0050] Looking at figure 2, a possible example of equipment to carry out the described process can be seen, in which a reactor (1) is contemplated with a first special mechanism to introduce the residue continuously without causing steam leaks and a possible depressurization of the reactor (2), and with a second mechanism to extract the residue continuously without causing steam leaks or a possible depressurization of the equipment (3).

[0051] Having sufficiently described the nature of the present invention, as well as the manner of putting it into practice, it is not considered necessary to make its explanation more extensive so that any expert in the field understands its scope and the advantages derived from it.

Claims

CLAIMS 1.- Process for the treatment of heterogeneous solid waste, particularly municipal waste, industrial waste similar to urban waste and hospital waste, characterized by comprising, at least: - an initial stage A) of introduction of the waste to be treated carried out continuously, without prior segregation, inside a hermetic reactor (1), already pressurized and at process temperature, without the use of locks, without the entry of waste in batches; - a stage B) of maintaining the residue inside the reactor (1) for a period of time between 20 and 60 minutes, during which the following is carried out: - a stage B1) of injection into the reactor (1), while the residue remains inside, of water vapor, at a pressure of between 2 and 12 bar, to maintain a constant and stable temperature of between 100°C and 180°C, while at the same time injecting a stream of hydroxyl radical (OH), at a flow rate ranging between 0 and 5000m 3 per minute, and - a step B2) of constant application of movement and agitation to the residue during its stay inside the reactor (1), to facilitate its tearing, morphological homogenization and the access of steam and hydroxyl radicals to all its parts; and - a final stage C) of extraction of the reactor residue (1) also carried out continuously without the need for locks, without batch extraction, without the need to depressurize the equipment. 2.- Process for treating heterogeneous solid waste, according to claim 1, characterized in that the pressure provided inside the reactor (1), at least during the stages (B1-B2) in which the waste remains in the reactor, ranges between 1 bar and 9 bar absolute. 3.- Process for treating heterogeneous solid waste, according to any of the preceding claims, characterized in that the injection of water vapor and the hydroxyl radical stream in stage (B1) is carried out through two different sources. external. 4.- Continuous treatment process for heterogeneous solid waste, according to any of the preceding claims, characterized in that the passage of the waste from atmospheric pressure to treatment pressure upon entering the equipment and vice versa during the exit of the waste from the equipment, occurs continuously, without interruptions, without the use of locks or product batches, and without the need to pressurize or depressurize the equipment.

Images