Household garbage treatment system for preparing methanol, treatment process and methanol preparation system

Abstract

The invention relates to the technical field of solid waste catalytic treatment, in particular to a household garbage treatment system for preparing methanol, a treatment process and a methanol preparation system. The household garbage treatment system comprises a screw feeder and a pyrolysis device, the screw feeder is provided with a first mixed material inlet, a recycled catalyst inlet and a second mixed material outlet, and the first mixed material inlet is used for inputting household garbage and a fresh catalyst; the pyrolysis device is provided with a second mixed material inlet and a recycled catalyst outlet, the second mixed material inlet is connected with the second mixed material outlet, and the recycled catalyst outlet is connected with the recycled catalyst inlet. According to the method, the waste catalyst obtained after the catalytic pyrolysis reaction of the household garbage is finished is used for in-situ ash fusion point regulation and control of the pyrolytic carbon, regulation and control of the ash fusion point are achieved, meanwhile, the sorting and separating step of the waste catalyst is avoided, and gasification products obtained after treatment comprise carbon monoxide and hydrogen and can be used for raw material gas for methanol synthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic treatment of solid waste, and in particular to a domestic waste treatment system, a treatment process and a methanol preparation system for preparing methanol. Background Art

[0002] Due to the complex composition, high water content, and low calorific value of domestic waste, achieving its reduction, harmlessness, and resource utilization has always been a major challenge facing the industry. At present, the main methods for treating domestic waste include sanitary landfill, incineration, composting, pyrolysis, and other methods. Among them, waste incineration is currently the most widely used treatment method. It fully oxidizes the combustible components through high-temperature combustion, and recovers waste heat to generate electricity or provide steam. However, waste incineration usually produces acidic gases, heavy metals, and especially harmful substances such as dioxins, which to a certain extent restrict the development of the waste incineration industry. In recent years, pyrolysis and gasification technology has emerged in the field of waste treatment due to its advantages such as strong adaptability to raw materials, no dioxin production, and low investment. In addition, the products obtained after pyrolysis and gasification of waste can be used in the production and preparation of methanol.

[0003] Garbage pyrolysis and gasification technology refers to the process of pyrolysis and gasification of organic components in domestic garbage under the condition of lack of oxygen or gasification agent to generate solid carbon, combustible gas and pyrolysis oil. The complex characteristics of domestic garbage components make direct gasification difficult. In recent years, the method of pyrolysis and gasification has received widespread attention. The method of pyrolysis and gasification mainly converts domestic garbage into relatively uniform pyrolysis carbon through pyrolysis reaction, and then uses the pyrolysis carbon to prepare synthesis gas in the gasifier. This method greatly reduces the difficulty of garbage gasification. Among the pyrolysis and gasification methods, water-coal slurry gasification technology has the advantages of simple furnace type and easy control of feed, and has been widely used as a raw material for preparing synthesis gas in gasifiers. Water-coal slurry gasification technology usually uses an entrained flow furnace type and adopts a liquid slag discharge method. This requires that the melting temperature of gasification ash slag must be lower than the gasification temperature, otherwise it will cause increased energy consumption and even affect the stable operation of the gasifier. However, in the existing domestic garbage pyrolysis process, no effective technical means have been provided to regulate the melting temperature of domestic garbage ash, and the operation stability of the gasifier cannot be guaranteed. In addition, there is still the problem of difficulty in recycling catalysts in the existing domestic waste pyrolysis process. Summary of the invention

[0004] In view of this, the present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present invention provides a domestic waste treatment system and treatment process, which can effectively control the melting temperature of domestic waste ash and directly recycle and reuse the waste catalyst.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] According to one aspect of the present application, an embodiment of the present application provides a domestic waste treatment system, the treatment system comprising:

[0007] A screw feeder, the screw feeder having a first mixed material inlet, a recovered catalyst inlet and a second mixed material outlet, the first mixed material inlet being used to input domestic waste and fresh catalyst;

[0008] A pyrolysis device is provided, wherein the pyrolysis device has a second mixed material inlet and a catalyst recovery outlet, wherein the second mixed material inlet is connected to the second mixed material outlet, and the catalyst recovery outlet is connected to the catalyst recovery inlet.

[0009] In addition, the domestic waste treatment system according to the present application may also have the following additional technical features:

[0010] The domestic waste treatment system also includes a crusher and a drying device, the drying device has a domestic waste inlet, a fresh catalyst inlet and a first mixed material outlet, the first mixed material inlet is connected to the first mixed material outlet; the crusher outlet is connected to the domestic waste inlet.

[0011] In some of the embodiments, the domestic waste treatment system also includes a mixing bin, which is located between the drying device and the screw feeder, the first mixed material outlet is connected to the inlet of the mixing bin, and the outlet of the mixing bin is connected to the first mixed material inlet.

[0012] In some of the embodiments, the domestic waste treatment system also includes a heat exchanger, a burner and a pulping device, the pyrolysis device also has a pyrolysis liquid product outlet and a heat supply inlet, and the pulping device has a pyrolysis liquid inlet; the pyrolysis liquid product outlet is connected to the inlet of the heat exchanger, the first outlet of the heat exchanger is connected to the pyrolysis liquid inlet, the second outlet of the heat exchanger is connected to the inlet of the burner, and the outlet of the burner is connected to the heat supply inlet.

[0013] In some of the embodiments, the pyrolysis device further has a pyrolysis gas outlet, and the pyrolysis gas outlet is connected to the gas inlet of the drying device.

[0014] In some of the embodiments, the drying device comprises a rotary kiln dryer.

[0015] In some of the embodiments, the pyrolysis apparatus comprises a rotary kiln pyrolysis reactor.

[0016] In some of the embodiments, the slurry making device further comprises a solid inlet, and the solid inlet is connected to the recovered catalyst outlet.

[0017] In some of the embodiments, the pulping device further has an outlet for materials to be gasified; the domestic waste treatment system further comprises a gasification device having an inlet for materials to be gasified, and the inlet for materials to be gasified is connected to the outlet for materials to be gasified.

[0018] According to another aspect of the present application, an embodiment of the present application provides a domestic waste treatment process for preparing methanol, the treatment process comprising the following steps:

[0019] Supplying a mixed material including the domestic waste to be processed and the fresh catalyst to a screw feeder for mixing to obtain a mixed material;

[0020] Supplying the mixed material to a pyrolysis device for pyrolysis treatment to obtain pyrolysis solid material and pyrolysis liquid material;

[0021] The pyrolysis solid material comprises a mixture of recovered catalyst and pyrolysis carbon, at least part of the pyrolysis solid material is returned to the screw feeder to participate in the reaction again, and at least part of the pyrolysis liquid material is supplied to the pulping device for pulping treatment.

[0022] In some embodiments, the treatment process comprises the following steps:

[0023] The domestic waste to be processed and the fresh catalyst are respectively supplied to a drying device for drying, and the domestic waste to be processed and the fresh catalyst are initially mixed in the drying device to obtain a first mixed material;

[0024] Supplying the first mixed material to a screw feeder for secondary mixing to obtain a second mixed material;

[0025] Supplying the second mixed material to a pyrolysis device for pyrolysis treatment to obtain pyrolysis solid material and pyrolysis liquid material;

[0026] The pyrolysis solid material comprises a mixture of recovered catalyst and pyrolysis carbon, at least part of the pyrolysis solid material is returned to the screw feeder to participate in the reaction again, and at least part of the pyrolysis liquid material is supplied to the pulping device for pulping treatment.

[0027] In some embodiments, the treatment process satisfies at least one of the following features (1) to (5): (1) the temperature of the drying treatment is 120°C to 150°C; (2) the mass of the fresh catalyst is 1% to 10% of the mass of the domestic waste to be treated; (3) the fresh catalyst includes a molecular sieve catalyst; (4) the temperature of the pyrolysis treatment is 350°C to 450°C; (5) the total mass of the pyrolysis solid material obtained by the pyrolysis treatment is m1, and the mass of the pyrolysis solid material returned to the screw feeder is m2, and m1 and m2 satisfy: m2 = (10% to 30%) * m1.

[0028] In some of the embodiments, the domestic waste to be processed is crushed waste, and the particle size of the crushed waste is ≤30 mm.

[0029] In some embodiments, the first mixed material passes through a mixing bin and is then supplied to the screw feeder.

[0030] In some embodiments, part of the pyrolyzed solid material is returned to the screw feeder to participate in the reaction again, and the remaining part of the pyrolyzed solid material is supplied to a pulping device for pulping treatment, and the slurry obtained by the pulping device is supplied to a gasification device for gasification treatment.

[0031] In some embodiments, the pyrolysis liquid material is supplied to a pulping device for pulping after heat exchange in a heat exchanger.

[0032] In some of the embodiments, part of the pyrolysis gas material obtained by the pyrolysis treatment is supplied to a burner after heat exchange through a heat exchanger, and the material combusted by the burner is supplied to a pyrolysis device for providing heat to the pyrolysis device.

[0033] In some of the embodiments, part of the pyrolysis gas material obtained by the pyrolysis treatment is supplied to a drying device for drying treatment.

[0034] According to another aspect of the present application, an embodiment of the present application provides a system for preparing methanol through coordinated gasification of domestic waste and biomass, which comprises the aforementioned domestic waste treatment system and a methanol synthesis device; wherein the outlet of the gasification device in the domestic waste treatment system is connected to the inlet of the methanol synthesis device.

[0035] Implementing the technical solution of the present invention has at least the following beneficial effects:

[0036] In the embodiment of the present application, the provided domestic waste treatment system and process mixes the mixed material through a screw feeder while conveying the mixed material, and then the mixed material enters the pyrolysis device for pyrolysis treatment, that is, in-situ catalytic pyrolysis treatment. After the pyrolysis treatment, the obtained pyrolysis solid material includes a mixture of recovered catalyst and pyrolytic carbon, and at least part of the pyrolysis solid material is returned to the screw feeder to participate in the reaction again. Therefore, the present application directly returns the pyrolysis solid material containing the recovered catalyst (waste catalyst) and pyrolytic carbon obtained after pyrolysis to the screw feeder for participating in the reaction again, that is, the waste catalyst after the catalytic pyrolysis reaction of domestic waste is used for the in-situ ash melting point regulation of pyrolytic carbon, and the ash melting point is regulated by the crystal phase conversion reaction of the waste catalyst and the ash in the pyrolytic carbon at high temperature, while avoiding the sorting and separation steps of the deactivated catalyst, reducing the cost of the catalyst, and giving full play to the utilization value of the catalyst.

[0037] Additional aspects and advantages of the present application will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Shown is a schematic diagram of a domestic waste treatment system provided by an embodiment of the present invention.

[0039] Figure 2 Shown is a schematic diagram of another domestic waste treatment system provided by an embodiment of the present invention.

[0040] Figure 3 Shown is a ternary phase diagram of the chemical composition of domestic waste ash calculated by Factsage according to an embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 10- Crusher;

[0043] 20-drying device; 201-domestic waste inlet; 202-fresh catalyst inlet; 203-first mixed material outlet; 204-gas inlet;

[0044] 30-mixing silo;

[0045] 40-screw feeder; 401-first mixed material inlet; 402-recovery catalyst inlet; 403-second mixed material outlet;

[0046] 50-pyrolysis device; 501-second mixed material inlet; 502-recovery catalyst outlet; 503-pyrolysis liquid product outlet; 504-heat supply inlet; 505-pyrolysis gas outlet;

[0047] 60-heat exchanger; 601-first outlet; 602-second outlet;

[0048] 70-burner;

[0049] 80- pulping device; 801- pyrolysis liquid inlet; 802- solid inlet; 803- outlet for gasified materials;

[0050] 90-gasification device; 901-inlet for materials to be gasified. DETAILED DESCRIPTION

[0051] The present application is further described below in conjunction with specific embodiments. It should be understood that these embodiments of the present application are only used to illustrate the present application and are not used to limit the scope of the present application.

[0052] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range or the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0053] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0054] As analyzed in the background technology, the current water-coal slurry gasification technology requires that the melting temperature of the gasified ash be lower than the gasification temperature, otherwise it will increase energy consumption and even affect the stable operation of the gasifier. At present, domestic waste can be mainly divided into kitchen waste, paper, wood and bamboo, rubber and plastic, textile, etc. Since paper accounts for a high proportion of domestic waste, and a certain amount of bleaching agent is added to paper during the production process, in addition, rubber and plastic in the garbage will also add some calcium carbonate during the production process to improve product performance. The above reasons lead to a high calcium content in domestic waste ash, which can reach about 50%. Calcium oxide (CaO), as an alkaline oxide, can both reduce the ash melting temperature and increase the ash melting temperature. When the calcium content is in a lower mass fraction range, calcium plays a positive role in regulating the ash melting temperature, and when the calcium content is at a higher level, it will cause the ash melting temperature to increase rapidly. At present, the characteristics of low silicon and aluminum content and high calcium content of domestic waste ash significantly increase its ash melting temperature. Therefore, how to efficiently and simply regulate the melting point of domestic waste ash has become a key factor and difficult problem to ensure the stable operation of the garbage gasification process.

[0055] In addition, the quality of oil products produced in the current garbage pyrolysis process is usually poor, especially the generation of tar will cause wall sticking and clogging, affecting the normal operation of the pyrolysis furnace. Usually, the treatment method for tar is mainly high-temperature cracking or water washing, but such methods cannot avoid the problems of high energy consumption, low efficiency or secondary pollution such as wastewater. Catalytic pyrolysis has certain applications in biomass pyrolysis reactions because it can reduce tar production and improve oil quality to a certain extent. Catalytic pyrolysis refers to the technology of directional regulation of pyrolysis products under the action of a catalyst. It is usually divided into in-situ catalysis and ex-situ catalysis. In-situ catalysis directly mixes the catalyst with the raw material for pyrolysis reaction, which has the advantages of sufficient contact and simple process. However, after the reaction is completed, the catalyst is mixed with pyrolysis carbon, and finally the problem of sorting and recycling of deactivated catalysts will be faced. At present, catalyst sorting is usually treated by screening or water washing, filtering and other methods, but these catalyst treatment methods inevitably increase the complexity of the in-situ catalytic pyrolysis process. Therefore, finding a simple technology for sorting or utilizing waste catalysts after catalytic pyrolysis reaction has become one of the problems to be solved in catalytic pyrolysis technology.

[0056] In addition, methanol is an important chemical raw material, which can be used as a gasoline additive, can be used to synthesize gasoline, can be used to synthesize acetic acid, acetic anhydride, or can be used in methanol engines. With the continuous expansion and development of methanol applications, the market for methanol is becoming more and more extensive. Therefore, the present invention treats urban domestic waste, and applies the gasification product obtained after the treatment, such as gasified coal gas rich in carbon monoxide and hydrogen, to methanol production, and uses it as a raw material to produce methanol, which is conducive to realizing the resource utilization of garbage pyrolysis carbon.

[0057] In view of this, the two main technical problems faced by the current in-situ catalytic pyrolysis process of domestic waste are: one is the problem of regulating the melting point of domestic waste ash, and the other is the problem of sorting, recycling and reuse of waste catalysts. The present invention provides a domestic waste treatment system and treatment process for preparing methanol, as well as a system for preparing methanol by coordinated biomass gasification of domestic waste. The system and process are a process system and method for coordinated treatment of catalytic pyrolysis waste catalysts and regulation of the melting temperature of domestic waste ash. They can be used to solve the problem of sorting and separating deactivated catalysts and the high melting point of pyrolysis carbon ash during the pyrolysis and gasification of domestic waste. The gasification product obtained after treatment can also be used in methanol production to achieve resource utilization. Next, this application is described in detail.

[0058] See also Figure 1 to Figure 2 As shown, in some embodiments, a domestic waste treatment system is provided, which includes a drying device 20, a screw feeder 40, a pyrolysis device 50 and a pulping device 80.

[0059] The drying device 20 can be used to dry the domestic waste to be treated and the fresh catalyst, and the domestic waste to be treated and the fresh catalyst can be preliminarily mixed in the drying device 20. The screw feeder 40 can be used to mix the domestic waste to be treated and the fresh catalyst again after the preliminarily mixing, and the screw feeder 40 can play the role of material transportation, that is, the screw feeder 40 can be used to transport the fully mixed mixture containing the domestic waste to be treated and the fresh catalyst to the pyrolysis device 50. The pyrolysis device 50 can be used to perform pyrolysis treatment on the domestic waste to be treated under the action of the catalyst. The pulping device 80 can be used to pulp the material obtained after the pyrolysis treatment.

[0060] In the present application, part of the pyrolysis solid material obtained after the pyrolysis treatment, that is, part of the pyrolysis solid material containing the recovered catalyst (waste catalyst) and pyrolysis carbon, is directly returned to the screw feeder 40 to participate in the reaction again, which not only realizes the direct recycling of the waste catalyst, but also reduces the cost of the catalyst by eliminating the need for sorting, screening and other treatments of the waste catalyst. In addition, the addition of the waste catalyst realizes the regulation of the melting temperature of the domestic waste ash, giving full play to the utilization value of the catalyst, and at the same time solves the problem of sorting and separating the deactivated catalyst (waste catalyst) in the pyrolysis and gasification process of domestic waste and the problem of the high melting point of the pyrolysis carbon ash. In detail:

[0061] (1) At present, biomass catalytic pyrolysis can improve product quality. Commonly used catalysts include activated carbon, metal oxides and molecular sieves. These catalysts are usually in the form of particles or powders. During in-situ catalytic pyrolysis, the catalyst is evenly mixed with the material. After pyrolysis, the catalyst is distributed in the pyrolysis carbon, which makes it difficult to recycle the waste catalyst. Therefore, it is necessary to solve the problem of difficulty in recycling the waste catalyst. (2) At present, the fluidized bed gasifier uses liquid slag discharge, which requires the gasification ash melting temperature to be lower than the gasification temperature. However, due to the high calcium content in the garbage, the melting point of the garbage ash is usually greater than 1500℃, which is much higher than the common operating temperature of 1300℃ of the fluidized bed. If the equipment is to operate stably, the gasifier temperature needs to be increased, resulting in a significant increase in gasification energy consumption. At the same time, the characteristics of low silicon and aluminum content and high calcium content in domestic garbage (as shown in Table 1 below) make it impossible to regulate the ash melting temperature like adding calcium to coal ash. Therefore, it is necessary to find a simple and effective method for regulating the melting temperature of domestic garbage ash, which is crucial for the stability of gasifier operation. (3) Some high-calcium coals usually choose to add quartz and other substances to control the ash melting point, but the calorific value of domestic garbage is much lower than that of coal. Even after pyrolysis, the calorific value of pyrolytic carbon is usually low. If SiO2 (such as quartz) is added to control the ash melting point during the gasification process, the calorific value of the garbage pyrolytic carbon will be further reduced, which may cause difficulties in the operation of the gasifier. Therefore, it is necessary to find a flux and control process that can control the ash melting point of garbage without having a significant impact on the calorific value of the raw materials.

[0062] Based on the above-mentioned problems, the inventors of this application have proposed the idea of ​​regulating the melting point of garbage ash with waste catalysts after extensive research, and based on this idea, proposed a process system and method for coordinated treatment of catalytic pyrolysis waste catalysts and regulation of the melting temperature of domestic garbage ash, which is mainly used to solve the problem of sorting and separation of deactivated catalysts during the pyrolysis and gasification of domestic garbage and the problem of high melting point of pyrolysis carbon ash. The idea of ​​regulating the melting point of garbage ash with waste catalysts is mainly to use the waste catalysts after the catalytic pyrolysis reaction of domestic garbage for in-situ ash melting point regulation of pyrolysis carbon, and to achieve ash melting point regulation through the crystal phase conversion reaction of waste catalysts and ash in pyrolysis carbon at high temperature, while avoiding the sorting and separation steps of deactivated catalysts, reducing the cost of catalysts, and giving full play to the utilization value of catalysts.

[0063] The principle of using waste catalyst to control the melting temperature of domestic waste ash is that according to the chemical composition of domestic waste ash, the ternary phase diagram is calculated by Factsage, Figure 3 It can be seen that by normalizing silicon dioxide (SiO2), aluminum oxide (Al2O3), and calcium oxide (CaO) as the main components of ash, only when the mass fraction of CaO in the ash is at a certain value can it be beneficial to reduce the melting temperature. The CaO content in domestic garbage is excessive, and other metal fluxes should be added to reduce the CaO content. Since the main components of molecular sieve catalysts are SiO2 and a small amount of Al2O3, the molecular sieve will not change its composition after catalytic pyrolysis and deactivation. In this way, according to the characteristics of high calcium content and low silicon and aluminum content in materials such as domestic garbage ash, an appropriate amount of waste molecular sieve flux is added to the ash. During high-temperature gasification, the molecular sieve skeleton structure collapses, and the main component SiO2 reacts chemically with the excess CaO in the ash, which reduces the ash melting point and solves the gasification problem caused by the high melting point of garbage ash.

[0064] It should be understood that Factsage software is widely used to calculate multivariate phase diagrams under different constraints, and has been widely studied in multivariate coal ash ash melting point and crystal composition characteristics. The model in this application is a ternary phase diagram model built after simplification and normalization based on the actual elemental composition characteristics of domestic garbage ash. The relationship between the content ratio of SiO2, Al2O3, and CaO and the ash melting point is usually a consensus in related fields.

[0065] In addition, during the in-situ catalytic pyrolysis process, the uniformity of the catalyst and material mixing usually has a significant impact on the catalytic effect. The present application, through the provision of the drying device 20 and the screw feeder 40, can not only play the role of drying and feeding, but also can achieve the full mixing of the domestic waste to be treated and the catalyst, without the need to add a separate mixing device, simplifying the process and avoiding the impact of the uneven mixing of the catalyst and the material on the catalytic effect during the in-situ catalytic pyrolysis process.

[0066] In the present application, the provided domestic waste treatment system can be applied in methanol production, such as being used in the preparation of methanol by coordinating urban domestic waste with biomass gasification, so as to achieve resource utilization and reduce the cost of methanol production.

[0067] It should be understood that in the production of methanol, synthesis gas, i.e., carbon monoxide (CO) + hydrogen (H2), is required. This application uses urban domestic waste as raw materials and converts domestic waste into CO and H2 through a series of chemical treatment processes. For example, in the gasification device of the garbage disposal system, pyrolytic carbon and pyrolysis liquid are used as raw materials for the gasification device. After the gasification reaction, synthesis gas composed of CO and H2 can be obtained. The synthesis gas can be used to prepare methanol after purification, compression, etc. The specific synthesis process and device of methanol are relatively mature in the prior art, and this application does not limit this. This application mainly provides synthesis gas composed of CO and H2 that can be used to produce methanol.

[0068] The specific equipment and treatment conditions of the domestic waste treatment system and process are described in more detail below.

[0069] In some specific embodiments, the domestic waste treatment system further includes a crusher 10, a mixing bin 30, a heat exchanger 60, a burner 70 and a gasification device 90. That is, the domestic waste treatment system may include a crusher 10, a drying device 20, a mixing bin 30, a screw feeder 40, a pyrolysis device 50, a heat exchanger 60, a burner 70, a pulping device 80 and a gasification device 90.

[0070] In the domestic waste treatment system, the crusher 10 can be used to crush the domestic waste to be treated, so as to improve the calorific value and uniformity of the waste material. The crusher 10 has an inlet and an outlet, and the domestic waste to be treated is supplied to the crusher 10 from the inlet, and the crusher 10 is used to crush the waste particle size to a target particle size, such as crushing the waste particle size to less than 30 mm, thereby improving the calorific value and uniformity of the waste material.

[0071] Optionally, before supplying the domestic waste to the crusher 10, the waste is first sorted. For example, the domestic waste after removing inorganic substances such as glass and metal after sorting is supplied to the crusher 10.

[0072] It should be noted that the present application has no special restrictions on the specific types of domestic waste. As an example, the domestic waste can be primary waste with inorganic matter removed, wherein the mass content ratio of paper, rubber and plastic, textile, and wood and bamboo is approximately in the range of 20-25%: 25-30%: 25-30%: 15-20%.

[0073] In the domestic waste treatment system, the drying device 20 can be used to dry the domestic waste to be treated and the fresh catalyst, and at the same time, the domestic waste to be treated and the fresh catalyst can be preliminarily mixed in the drying device 20. The drying device 20 has a domestic waste inlet 201, a fresh catalyst inlet 202 and a first mixed material outlet 203; the outlet of the crusher 10 is connected to the domestic waste inlet 201 of the drying device 20, and the fresh catalyst inlet 202 can be used to put in fresh catalyst. Optionally, the domestic waste inlet 201 and the fresh catalyst inlet 202 can be the same inlet, or can also be two inlets, such as the fresh catalyst inlet 202 can be set on a pipe connected to the domestic waste inlet 201, and this application does not limit this.

[0074] It should be understood that fresh catalyst refers to a catalyst that has not participated in any reaction.

[0075] Optionally, the drying device 20 adopts a rotary kiln dryer. By adopting a rotary kiln dryer, that is, a drying rotary kiln, both drying of the material and mixing of the material can be achieved.

[0076] It should be pointed out that the present application does not limit the specific structure or model of the rotary kiln dryer. Its specific structure or form can refer to the relevant prior art. As long as it is a rotary kiln type and can be used for drying and mixing, it does not limit the purpose of the present application.

[0077] Thus, the domestic waste material crushed by the crusher 10 can be dried together with the fresh catalyst, etc. in the rotary kiln dryer, wherein the fresh catalyst can be in the form of powder or granules. In this way, part of the moisture in the waste can be removed under high temperature and the rotation of the furnace body, and the catalyst and the domestic waste material can be preliminarily mixed, and the mixed material falls into the mixing bin 30 through the first mixed material outlet 203 of the drying device 20.

[0078] Optionally, the drying temperature of the drying treatment is 120°C to 150°C.

[0079] Optionally, the mass of the fresh catalyst is 1% to 10% of the mass of the domestic waste to be treated; that is, the mass ratio of the fresh catalyst to the domestic waste to be treated is 1% to 10%. Preferably, the mass of the fresh catalyst is about 5% of the mass of the domestic waste to be treated.

[0080] Optionally, the fresh catalyst used in the present application may be a molecular sieve catalyst, for example, the catalyst may be a ZSM-5 molecular sieve catalyst, a USY molecular sieve catalyst, and the like.

[0081] In the domestic waste treatment system, the mixing bin 30 is located between the drying device 20 and the screw feeder 40, and the mixing bin 30 has an inlet and an outlet. The first mixed material outlet 203 of the drying device 20 is connected to the inlet of the mixing bin 30, and the outlet of the mixing bin 30 is connected to the first mixed material inlet 401 of the screw feeder 40.

[0082] By setting a mixing bin 30 between the drying device 20 and the screw feeder 40, the mixing bin 30 can be used to temporarily store or transfer the mixed material obtained after mixing in the drying device 20, which is beneficial to improving the processing flexibility of the entire system and facilitating operation.

[0083] Optionally, in some cases, the mixing bin 30 may not be provided, for example, the first mixed material outlet 203 of the drying device 20 is directly connected to the first mixed material inlet 401 of the screw feeder 40 .

[0084] The specific structural form of the mixing bin 30 can be selected and set according to actual conditions, and this application does not limit this.

[0085] In the domestic waste treatment system, the screw feeder 40 has a first mixed material inlet 401, a recovered catalyst inlet 402, and a second mixed material outlet 403. The first mixed material inlet 401 of the screw feeder 40 is connected to the first mixed material outlet 203 of the drying device 20, or the first mixed material inlet 401 of the screw feeder 40 is connected to the outlet of the mixing bin 30, the recovered catalyst inlet 402 can be used to be connected to the recovered catalyst outlet 502 of the pyrolysis device 50, and the second mixed material outlet 403 can be used to be connected to the second mixed material inlet 501 of the pyrolysis device 50. Optionally, the first mixed material inlet 401 and the recovered catalyst inlet 402 can be the same inlet, or can also be two inlets, which is not limited in the present application.

[0086] The screw feeder 40 can play the role of material transportation and also play the role of material mixing. That is, the catalyst (including fresh catalyst and recycled catalyst) and the garbage material can be further mixed under the action of the screw feeder 40. At the same time, the screw feeder 40 can play the role of material transportation, that is, the fully mixed material is transported to the pyrolysis device 50.

[0087] In the present application, the pyrolysis solid material containing the recovered catalyst obtained after pyrolysis in the pyrolysis device 50 can be directly returned to the screw feeder 40 for further reaction without returning to the drying device 20, which can save energy and simplify the process.

[0088] Therefore, since the uniformity of the mixture of catalyst and material in the in-situ catalytic pyrolysis process usually has a significant impact on the catalytic effect, the present application can not only dry and convey materials through the arrangement of the drying device 20 and the screw feeder 40, but also achieve full mixing of the domestic waste to be treated and the catalyst, without the need to add a separate mixing device, thus simplifying the process and reducing equipment costs.

[0089] In the domestic waste treatment system, the pyrolysis device 50 has a second mixed material inlet 501, a catalyst recovery outlet 502 and a pyrolysis liquid product outlet 503. Furthermore, the pyrolysis device 50 also has a heat supply inlet 504; the pyrolysis device 50 also has a pyrolysis gas outlet 505.

[0090] In the domestic waste treatment system, the heat exchanger 60 has an inlet, a first outlet 601 and a second outlet 602. The burner 70 has an inlet and an outlet.

[0091] In the domestic waste treatment system, the drying device 20 can also have a gas outlet.

[0092] Thus, the second mixed material inlet 501 of the pyrolysis device 50 is connected to the second mixed material outlet 403 of the screw feeder 40; the catalyst recovery outlet 502 (also called the pyrolysis solid material outlet) of the pyrolysis device 50 is connected to the catalyst recovery inlet 402 of the screw feeder 40, and the catalyst recovery outlet 502 of the pyrolysis device 50 can also be connected to the solid inlet 802 of the pulping device 80. The pyrolysis liquid product outlet 503 of the pyrolysis device 50 is connected to the inlet of the heat exchanger 60, or the pyrolysis liquid product outlet 503 of the pyrolysis device 50 is connected to the pyrolysis liquid inlet 801 of the pulping device 80, the first outlet 601 of the heat exchanger 60 is connected to the pyrolysis liquid inlet 801 of the pulping device 80, the second outlet 602 of the heat exchanger 60 is connected to the inlet of the burner 70, and the outlet of the burner 70 is connected to the heat supply inlet 504 of the pyrolysis device 50. The pyrolysis gas outlet 505 of the pyrolysis device 50 is connected to the gas inlet 204 of the drying device 20.

[0093] Optionally, the pyrolysis device 50 uses a rotary kiln pyrolysis reactor.

[0094] In the present application, the mixed material after mixing by the screw feeder 40 is supplied to the pyrolysis device 50, such as supplied to the rotary kiln pyrolysis reactor for anaerobic pyrolysis reaction. The rotary kiln pyrolysis reactor is used to further enhance the uniformity of mixing the garbage material and the catalyst by rotating the furnace body, so that the catalyst can fully exert its catalytic effect. In the pyrolysis device 50, the anaerobic pyrolysis reaction carried out by relying on the catalytic effect of the catalyst refers to the thermochemical conversion process of the garbage material in an anaerobic environment. The whole reaction process is relatively complex, usually including thermal cracking, polycondensation, dehydrogenation and hydrogenation, etc. In addition, due to the addition of the catalyst, the pyrolysis process will also undergo catalytic cracking, shape-selective catalysis and other reactions, and the final raw materials are converted into small molecular hydrocarbons, carbon monoxide, carbon dioxide, coke and other substances.

[0095] Optionally, the temperature of the pyrolysis treatment is 350° C. to 450° C. By controlling the pyrolysis temperature within this range, a higher pyrolysis carbon yield can be obtained.

[0096] After the pyrolysis reaction is completed, pyrolysis solid products (pyrolysis solid materials), pyrolysis liquid products (pyrolysis liquid materials) and pyrolysis gas products are obtained, wherein the pyrolysis solid products mainly include catalysts and pyrolysis carbon; a part of the pyrolysis solid products can be returned to the screw feeder 40 through the catalyst recovery outlet 502 to participate in the reaction again, and another part of the pyrolysis solid products can enter the pulping device 80 through the catalyst recovery outlet 502 for pulping treatment. Pyrolysis liquid products such as light oil or hydrocarbons can enter the heat exchanger 60 through the pyrolysis liquid product outlet 503 for heat exchange, and the pyrolysis liquid products after heat exchange can enter the pulping device 80 for pulping treatment. In addition, the pyrolysis liquid products and / or pyrolysis gas products can enter the heat exchanger 60 for heat exchange, and the heat exchanged materials (such as non-condensable gas) enter the burner 70 through the second outlet 602 of the heat exchanger 60 for combustion treatment, and the burned materials can be supplied to the heat supply inlet 504 of the pyrolysis device 50 through the outlet of the burner 70 for heat supply of the pyrolysis device 50. Since the pyrolysis gas product still has a certain amount of heat, it can be supplied to the gas inlet 204 of the drying device 20 through the pyrolysis gas outlet 505, and the pyrolysis gas product is used to heat the drying device 20. In addition, the outlet flue gas is purified and discharged after meeting the standards.

[0097] That is, in the embodiment of the present application, under the action of the catalyst, the domestic waste undergoes an in-situ catalytic pyrolysis reaction in the pyrolysis device 50, the heavy tar components in the pyrolysis liquid produced by pyrolysis are further cracked into small molecular hydrocarbon substances, the light oil and part of the water are cooled by the heat exchanger 60 (such as a condenser) and used in the subsequent pulping device 80, the non-condensable gas produced by pyrolysis is burned by the burner 70 and used for heating the pyrolysis device 50, the outlet gas of the pyrolysis device 50 still has a certain amount of heat, which can be used for heating the drying device 20, and the outlet flue gas is purified and discharged after meeting the standards.

[0098] Further, after the pyrolysis is completed, the obtained pyrolysis solid material mainly includes waste catalyst and pyrolytic carbon, and the catalyst and pyrolytic carbon can be discharged from the tail of the pyrolysis device 50, such as through the catalyst recovery outlet 502. Among them, part of the pyrolysis solid material can be returned to the screw feeder 40, and the remaining part of the pyrolysis solid material can be supplied to the pulping device 80. Optionally, in some embodiments, the total mass of the pyrolysis solid material obtained by the pyrolysis treatment is m1, and the mass of the pyrolysis solid material returned to the screw feeder 40 is m2, and m1 and m2 satisfy: m2 = (10% ~ 30%) * m1. As an example, m2 = 10% * m1, 15% * m1, 20% * m1, 25% * m1 or 30% * m1, etc.

[0099] In the present application, after a single-pass pyrolysis reaction, the catalyst may still have a certain activity, and the pyrolytic carbon obtained by pyrolysis usually has a rich pore structure and some trace metals, which shows certain benefits for tar treatment. Therefore, the pyrolytic carbon and catalyst mixture do not need to be sorted, and 10% to 30% of the pyrolytic solid material is re-added to the screw feeder 40 and sent to the pyrolysis device 50 to participate in the reaction again, thereby improving the utilization efficiency of the catalyst. The remaining pyrolytic solid material enters the pulping device 80, and after grinding, it is mixed with part of the pyrolysis oil to make pulp for the subsequent gasification system raw material.

[0100] Therefore, by directly recycling the mixture containing waste catalyst and pyrolytic carbon, there is no need to consider the separation of the catalyst and pyrolytic carbon in the mixture. On the one hand, the amount of catalyst used in the whole process can be reduced, thereby reducing the catalyst cost. On the other hand, the residual value of the catalyst can be fully utilized, which can play a role in regulating the melting temperature of domestic waste ash.

[0101] In the domestic waste treatment system, the pulping device 80 has a pyrolysis liquid inlet 801, and the pulping device 80 also has a solid inlet 802; the pulping device 80 also has a material outlet 803 to be gasified. The gasification device 90 has a material inlet 901 to be gasified.

[0102] The pyrolysis liquid inlet 801 of the pulping device 80 can be connected to the first outlet 601 of the heat exchanger 60; the solid inlet of the pulping device 80 can be connected to the catalyst recovery outlet 502 (pyrolysis solid material outlet) of the pyrolysis device 50; the material outlet 803 to be gasified of the pulping device 80 is connected to the material inlet 901 to be gasified of the gasification device 90.

[0103] It should be pointed out that in the present application, there is no specific restriction on the specific settings of the inlets and outlets of each device in the domestic waste treatment system. As long as each inlet or outlet can be used to input corresponding materials or output corresponding materials, it does not limit the purpose of the present invention. As an example, the domestic waste inlet 201 and the fresh catalyst inlet 202 of the drying device 20 can be one inlet, or two inlets, or the fresh catalyst inlet 202 can be connected to the pipeline connected to the domestic waste inlet 201, which can be selected and set according to the specific actual situation.

[0104] In the present application, the pulping process of the pulping device 80 can obtain a slurry composed of pyrolytic carbon mixed with part of the catalyst and oil, and the slurry is transported to a gasification device 90 such as a gasifier. Under the high temperature environment of the gasifier, the catalyst skeleton structure collapses, and the main component becomes SiO2, which combines with CaO in the pyrolytic carbon ash at high temperature to consume excess CaO in the ash, thereby completing the regulation of the melting temperature of the garbage pyrolysis carbon ash and realizing the direct utilization of the catalytic pyrolysis waste catalyst.

[0105] It should be pointed out that the above-mentioned pulping device and gasification device both adopt existing technologies. For example, the gasification device can adopt an entrained bed. The specific structure and operating reaction principle of the pulping device and the gasification device can refer to relevant existing technologies (such as related coal gasification equipment), and this application does not limit this.

[0106] In some embodiments, a domestic waste treatment process is also provided, the treatment process comprising the following steps:

[0107] The domestic waste to be treated and the fresh catalyst are respectively supplied to the drying device 20 for drying, and the domestic waste to be treated and the fresh catalyst are initially mixed in the drying device 20 to obtain a first mixed material;

[0108] The first mixed material is supplied to the screw feeder 40 for secondary mixing to obtain a second mixed material;

[0109] The second mixed material is supplied to the pyrolysis device 50 for pyrolysis treatment to obtain pyrolysis solid material and pyrolysis liquid material;

[0110] The pyrolysis solid material includes a mixture of recovered catalyst and pyrolysis carbon, at least part of the pyrolysis solid material is returned to the screw feeder 40 to participate in the reaction again, and at least part of the pyrolysis liquid material is supplied to the pulping device 80 for pulping treatment.

[0111] The domestic waste treatment process provided by the embodiment of the present invention is simple, easy to operate, highly feasible, and easy to realize industrialization.

[0112] It should be understood that the "domestic waste treatment system" and the "domestic waste treatment process" are based on the same inventive concept. All the features and advantages described in the previous article for the "domestic waste treatment system" are also applicable to the "domestic waste treatment process" and will not be elaborated here one by one.

[0113] Optionally, the domestic waste to be processed is crushed waste, and the particle size of the crushed waste is ≤30mm.

[0114] In the present application, before the domestic waste is supplied to the drying device 20, it needs to be crushed first. For example, the domestic waste after sorting and removing inorganic materials such as glass and metal is crushed to a particle size of less than 30 mm on the crusher 10 to improve the calorific value and uniformity of the waste material. Then, the crushed waste can be supplied to the drying device 20.

[0115] Optionally, the domestic waste material crushed by the crusher 10 can be dried together with a fresh catalyst in a rotary kiln dryer, wherein the fresh catalyst can be in powder or granular form. In this way, part of the water in the waste can be removed under high temperature and the rotation of the furnace body, and the catalyst and the domestic waste material can be preliminarily mixed, and the obtained first mixed material falls into the mixing bin 30 through the first mixed material outlet 203 of the drying device 20.

[0116] In the embodiment of the present application, the drying temperature is 120°C to 150°C; for example, it can be any point value among 120°C, 130°C, 140°C, 150°C, or a range value between any two of them.

[0117] Optionally, the mass of the fresh catalyst is 1% to 10% of the mass of the domestic waste to be treated; that is, the mass ratio of the fresh catalyst to the domestic waste to be treated is 1% to 10%, preferably about 5%. For example, the mass ratio can be any one of 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, or a range between any two of them.

[0118] Optionally, the fresh catalyst used in the present application may be a molecular sieve catalyst, for example, the catalyst may be a ZSM-5 molecular sieve catalyst, a USY molecular sieve catalyst, and the like.

[0119] Optionally, the first mixed material is supplied to the screw feeder 40 after passing through the mixing bin 30. That is, the first mixed material obtained after being processed by the drying device 20 enters the mixing bin 30, and the material coming out of the mixing bin 30 is supplied to the screw feeder 40. The screw feeder 40 can play the role of material transportation and the role of mixing materials. Under the action of the screw feeder 40, the second mixed material can be obtained.

[0120] The second mixed material can be sent to the pyrolysis device 50 for anaerobic pyrolysis reaction under the action of the screw feeder 40. For example, by using a rotary kiln pyrolysis reactor, the uniformity of mixing the garbage material and the catalyst is further enhanced by rotating the furnace body, so that the catalyst can fully exert its catalytic effect. Optionally, the temperature of the pyrolysis treatment is 350°C to 450°C. By controlling the pyrolysis temperature within this range, a higher pyrolysis carbon yield can be obtained. As an example, the temperature of the pyrolysis treatment can be any point value of 350°C, 360°C, 370°C, 380°C, 400°C, 420°C, 450°C, or a range value between any two of them.

[0121] After the pyrolysis reaction is completed, pyrolysis solid materials, pyrolysis liquid materials and pyrolysis gas products are obtained, wherein the pyrolysis solid materials mainly include catalysts and pyrolysis carbon. Optionally, part of the pyrolysis solid materials are returned to the screw feeder 40 to participate in the reaction again, and the remaining pyrolysis solid materials are supplied to the pulping device 80 for pulping treatment, and the slurry obtained by the pulping device 80 is supplied to the gasification device 90 for gasification treatment.

[0122] Optionally, the total mass of the pyrolysis solid material obtained by the pyrolysis treatment is m1, and the mass of the pyrolysis solid material returned to the screw feeder 40 is m2, and m1 and m2 satisfy: m2 = (10% to 30%) * m1. In the embodiment of the present application, 10% to 30% of the pyrolysis solid material is added back to the screw feeder 40 and sent to the pyrolysis device 50 to participate in the reaction again, thereby improving the utilization efficiency of the catalyst. The remaining pyrolysis solid material enters the pulping device 80, and after grinding, it is mixed with part of the pyrolysis oil to make pulp for the subsequent gasification system raw material.

[0123] Therefore, based on the above, it can be known that the domestic waste treatment system and process provided by the present application is a process system and method that can coordinately treat domestic waste catalytic pyrolysis waste catalyst and domestic waste ash melting temperature control, which not only realizes the direct utilization of deactivated waste catalysts, avoids complex catalyst sorting and separation processes, reduces the difficulty of the process route and improves the utilization value of waste catalysts; and in-situ controls the ash melting point of high-calcium, low-silicon-aluminum content materials (such as domestic waste) from the raw material end, reducing the complexity of the subsequent ash melting point control process. At the same time, due to the role of the catalyst in the pyrolysis reaction process, the quality of the pyrolysis oil is improved, the oxygen content is reduced, and the calorific value is increased; in this way, the subsequent pyrolysis oil and pyrolysis carbon are mixed and pulped as gasification raw materials, and the calorific value of the raw materials is also increased accordingly; therefore, the influence of the waste ash melting point control by the waste catalyst on the calorific value of the gasification raw material is smaller than that of quartz and other materials.

[0124] In some embodiments, a system for preparing methanol by gasifying domestic waste in coordination with biomass is also provided, which includes the aforementioned domestic waste treatment system and a methanol synthesis device; wherein the outlet of the gasification device 90 in the domestic waste treatment system is connected to the inlet of the methanol synthesis device. The domestic waste treatment system and process of the present application can be applied to the preparation of methanol by gasifying urban domestic waste in coordination with biomass to achieve resource utilization and reduce the production cost of methanol. For the remaining devices in the methanol preparation system, such as the methanol synthesis device, etc., reference can be made to the prior art, and no limitation is made thereto.

[0125] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this area or the product instructions are used. If the manufacturer of the reagents, materials or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0126] Example 1

[0127] A process for treating domestic waste comprises the following steps:

[0128] First, the domestic waste after sorting and removing inorganic materials such as glass and metal is crushed to a particle size of less than 30mm on a crusher;

[0129] Then, the domestic waste to be treated and the fresh catalyst (molecular sieve catalyst, such as ZSM-5 molecular sieve catalyst or USY molecular sieve catalyst) are respectively supplied to a drying device (rotary furnace dryer) for drying treatment, the drying temperature is 120° C. to 150° C., and the fresh catalyst can be selected in powder or granular form; the mass ratio of the fresh catalyst to the domestic waste to be treated is 1% to 10%, preferably about 5%; the domestic waste to be treated and the fresh catalyst are initially mixed in the drying device to obtain a first mixed material;

[0130] The first mixed material obtained after being processed by the drying device enters into the mixing bin, and the material coming out of the mixing bin is then supplied to the screw feeder, and is mixed for the second time in the screw feeder to obtain the second mixed material;

[0131] The second mixed material is sent to the pyrolysis device for oxygen-free pyrolysis reaction under the action of the screw feeder. The rotary kiln pyrolysis reactor is used to further enhance the uniformity of the mixing of the garbage material and the catalyst through the rotation of the furnace body, so that the catalyst can fully exert its catalytic effect. Relying on the catalytic effect of the catalyst, the temperature of the pyrolysis treatment can be set to a lower temperature of 350℃ to 450℃ to obtain a higher pyrolysis carbon yield.

[0132] Under the action of the catalyst, the domestic waste undergoes an in-situ catalytic pyrolysis reaction in the pyrolysis device. The heavy tar components in the pyrolysis liquid produced by pyrolysis are further cracked into small molecular hydrocarbon substances. The light oil and part of the water are cooled by a heat exchanger (such as a condenser) and used in the subsequent pulping device. The non-condensable gas produced by pyrolysis is burned in a burner and used for heating the pyrolysis device. The outlet gas of the pyrolysis device still has a certain amount of heat and can be used for heating the drying device. The outlet flue gas is purified and discharged after meeting the standards.

[0133] After the pyrolysis is completed, the pyrolysis solid materials obtained mainly include waste catalyst and pyrolytic carbon, and the catalyst and pyrolytic carbon can be discharged from the tail of the pyrolysis device. Among them, part of the pyrolysis solid materials can be returned to the screw feeder, and the remaining part of the pyrolysis solid materials can be supplied to the pulping device. In the present application, after a single-pass pyrolysis reaction, the catalyst may still have a certain activity, and the pyrolytic carbon obtained by pyrolysis usually has a rich pore structure and some trace metals, which shows certain benefits for tar treatment. Therefore, the pyrolytic carbon and catalyst mixture does not need to be sorted, and 10% to 30% of the pyrolysis solid materials are re-added to the screw feeder and sent to the pyrolysis device to participate in the reaction again, thereby improving the utilization efficiency of the catalyst. The remaining pyrolysis solid materials enter the pulping device, and after grinding, they are mixed with part of the pyrolysis oil to make pulp for the subsequent gasification system raw materials.

[0134] In order to verify that adding spent catalysts can be used to regulate the ash-ash melting problem of domestic waste, the following experimental verification was conducted in this example.

[0135] The domestic waste ash described in Table 1 below was used as a base, to which different proportions of ZSM-5 catalyst were added, and the ash melting point temperature was measured. The results are shown in Table 2.

[0136] Table 1 Chemical composition and flow temperature of paper ash and domestic garbage ash

[0137]

[0138] In Table 1, FT means flow temperature.

[0139] In addition, according to the national standard GB / T219-2008, there are corresponding descriptions for the four characteristic temperatures of ash, so the characteristic descriptions of paper ash, domestic garbage ash, etc. in Table 1 can refer to this description.

[0140] As can be seen from Table 1, the calcium content in paper ash is extremely high. Since about 20-25% of the garbage is paper, the calcium content in garbage ash is also relatively high to a certain extent.

[0141] Table 2 Ash melting temperature of household garbage ash mixed with catalyst flux

[0142]

[0143] In Table 2, directly adding SiO2 is used to represent molecular sieve catalysts. Since molecular sieve catalysts are directly added, except for pure silicon molecular sieves, the SiO2 content in other molecular sieve catalysts is different due to different silicon-aluminum ratios. Therefore, the amount of SiO2 added is used for judgment here. The actual operation can be adjusted according to the SiO2 content in the molecular sieve.

[0144] As shown in Table 2, adding molecular sieve catalyst can adjust the melting temperature of domestic waste ash. When the addition ratio is 20%, the ash melting point is reduced from 1442℃ to 1111℃, but when the addition amount is greater than 20%, the melting temperature begins to rise. Therefore, in actual production, a corresponding proportion of molecular sieve catalyst can be added to significantly reduce its ash melting point.

[0145] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0146] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0147] It should be noted that the term "and / or" or " / " used in this document is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The singular forms of "a", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0148] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A, B are listed, the phrase "at least one of A, B" means only A; only B; or A and B. In another example, if items A, B, C are listed, the phrase "at least one of A, B, C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A domestic waste treatment system for preparing methanol, characterized in that: The domestic waste treatment system comprises: A screw feeder (40), wherein the screw feeder (40) has a first mixed material inlet (401), a recovered catalyst inlet (402) and a second mixed material outlet (403), wherein the first mixed material inlet (401) is used to input domestic waste and fresh catalyst; A pyrolysis device (50), wherein the pyrolysis device (50) has a second mixed material inlet (501) and a catalyst recovery outlet (502), wherein the second mixed material inlet (501) is connected to the second mixed material outlet (403), and the catalyst recovery outlet (502) is connected to the catalyst recovery inlet (402).

2. The domestic waste treatment system according to claim 1, characterized in that: The domestic waste treatment system further comprises a crusher (10) and a drying device (20), wherein the drying device (20) has a domestic waste inlet (201), a fresh catalyst inlet (202) and a first mixed material outlet (203), wherein the first mixed material inlet (401) is connected to the first mixed material outlet (203); The outlet of the crusher (10) is connected to the domestic waste inlet (201).

3. The domestic waste treatment system according to claim 2, characterized in that: The drying device (20) comprises a rotary kiln dryer; and / or, The pyrolysis device (50) comprises a rotary kiln pyrolysis reactor.

4. The domestic waste treatment system according to claim 2, characterized in that: The domestic waste treatment system further comprises a mixing bin (30), wherein the mixing bin (30) is located between the drying device (20) and the screw feeder (40), the first mixed material outlet (203) is connected to the inlet of the mixing bin (30), and the outlet of the mixing bin (30) is connected to the first mixed material inlet (401); and / or, The domestic waste treatment system further comprises a heat exchanger (60), a burner (70) and a pulping device (80), the pyrolysis device (50) further comprises a pyrolysis liquid product outlet (503) and a heat supply inlet (504), and the pulping device (80) comprises a pyrolysis liquid inlet (801); The pyrolysis liquid product outlet (503) is connected to the inlet of the heat exchanger (60), the first outlet (601) of the heat exchanger (60) is connected to the pyrolysis liquid inlet (801), the second outlet (602) of the heat exchanger (60) is connected to the inlet of the burner (70), and the outlet of the burner (70) is connected to the heat supply inlet (504); and / or, The pyrolysis device (50) further comprises a pyrolysis gas outlet (505), and the pyrolysis gas outlet (505) is connected to the gas inlet (204) of the drying device (20).

5. The domestic waste treatment system according to claim 4, characterized in that: The slurry making device (80) further comprises a solid inlet (802), and the solid inlet (802) is connected to the recovered catalyst outlet (502).

6. The domestic waste treatment system according to claim 4, characterized in that: The pulping device (80) also has an outlet (803) for the material to be gasified; The domestic waste treatment system further comprises a gasification device (90), wherein the gasification device (90) comprises an inlet (901) for materials to be gasified, and the inlet (901) for materials to be gasified is connected to an outlet (803) for materials to be gasified.

7. A process for treating domestic waste for preparing methanol, characterized in that: The treatment process comprises the following steps: Supplying a mixed material containing the domestic waste to be processed and a fresh catalyst to a screw feeder (40) for mixing to obtain a mixed material; Supplying the mixed material to a pyrolysis device (50) for pyrolysis treatment to obtain pyrolysis solid material and pyrolysis liquid material; The pyrolysis solid material comprises a mixture of recovered catalyst and pyrolysis carbon, at least part of the pyrolysis solid material is returned to the screw feeder (40) to participate in the reaction again, and at least part of the pyrolysis liquid material is supplied to the pulping device (80) for pulping treatment.

8. The domestic waste treatment process according to claim 7, characterized in that: The processing process also includes: The domestic waste to be treated and the fresh catalyst are respectively supplied to a drying device (20) for drying treatment, and the domestic waste to be treated and the fresh catalyst are initially mixed in the drying device (20) to obtain a first mixed material; then, the first mixed material is supplied to a screw feeder (40) for mixing.

9. The domestic waste treatment process according to claim 8, characterized in that: The treatment process satisfies at least one of the following characteristics (1) to (11): (1) The drying temperature is 120°C to 150°C; (2) The mass of the fresh catalyst is 1% to 10% of the mass of the domestic waste to be treated; (3) The fresh catalyst includes a molecular sieve catalyst; (4) The temperature of the pyrolysis treatment is 350° C. to 450° C.; (5) The total mass of the pyrolysis solid material obtained by the pyrolysis treatment is m1, and the mass of the pyrolysis solid material returned to the screw feeder (40) is m2, wherein m1 and m2 satisfy: m2 = (10% to 30%) * m1; (6) The domestic waste to be processed is crushed waste, and the particle size of the crushed waste is ≤30 mm; (7) The first mixed material is supplied to the screw feeder (40) after passing through the mixing bin (30); (8) a portion of the pyrolyzed solid material is returned to the screw feeder (40) to participate in the reaction again, and the remaining portion of the pyrolyzed solid material is supplied to the pulping device (80) for pulping treatment, and the pulp obtained by the pulping device (80) is supplied to the gasification device (90) for gasification treatment; (9) The pyrolysis liquid material is supplied to a pulping device (80) for pulping after heat exchange in a heat exchanger (60); (10) Part of the pyrolysis gas material obtained by the pyrolysis treatment is supplied to the burner (70) after heat exchange via the heat exchanger (60), and the material after combustion in the burner (70) is supplied to the pyrolysis device (50) for supplying heat to the pyrolysis device (80); (11) Part of the pyrolysis gas material obtained by the pyrolysis treatment is supplied to a drying device (20) for drying treatment.

10. A system for preparing methanol by gasifying domestic waste and biomass, characterized in that: A domestic waste treatment system comprising any one of claims 1 to 6, and a methanol synthesis device; Wherein, the outlet of the gasification device (90) in the domestic waste treatment system is connected to the inlet of the methanol synthesis device.

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