阅读说明：本技术 一种废轮胎热解与生活垃圾炉耦合燃烧的工艺方法 (Process method for pyrolysis of waste tires and coupled combustion of household garbage furnace ) 是由 吕洪炳 林少平 潘宇涵 韩东浩 黄群星 陈齐勇 何石鱼 周永刚 钱勇夫 赵凯航 于 2021-09-24 设计创作，主要内容包括：本发明公开了一种废轮胎热解与生活垃圾炉耦合燃烧以控制二噁英生成,提高能源利用效率的方法。该方法将废轮胎热解过程中产生的高热值热解油、气引入生活垃圾焚烧炉中混合燃烧,优化垃圾燃烧过程,利用废轮胎热解油、气中的含硫化合物燃烧生成的二氧化硫抑制前驱物“氯气”的形成和使催化剂“铜”中毒,从而间接抑制二噁英的生成。该方法在提高燃烧效率的同时可抑制燃烧过程中二噁英的形成,提高了能源整体利用效率,同时降低生活垃圾焚烧尾气中二噁英的排放。(The invention discloses a method for controlling generation of dioxin and improving energy utilization efficiency by waste tire pyrolysis and household garbage furnace coupled combustion. The method introduces high-heat value pyrolysis oil and gas generated in the pyrolysis process of the waste tires into a household garbage incinerator for mixed combustion, optimizes the garbage combustion process, and utilizes sulfur dioxide generated by combustion of sulfur-containing compounds in the pyrolysis oil and gas of the waste tires to inhibit the formation of precursor chlorine and poison catalyst copper, thereby indirectly inhibiting the generation of dioxin. The method can improve the combustion efficiency, inhibit the formation of dioxin in the combustion process, improve the overall utilization efficiency of energy, and reduce the emission of dioxin in the incineration tail gas of household garbage.)

1. A process method for optimizing a combustion process and inhibiting the generation of refuse-incinerated dioxin by pyrolysis of waste tires and coupling combustion of a household garbage furnace is characterized by comprising the following steps of: the method comprises the following steps:

(1) and continuously feeding the waste tire particles into a pyrolysis furnace for pyrolysis in an inert atmosphere environment isolated from air, and obtaining three products of pyrolytic carbon black, pyrolytic oil and pyrolytic gas after pyrolysis reaction. The pyrolytic carbon falls into the collection bag by the action of gravity, and the pyrolysis oil is collected after passing through condensing equipment condensation, and pyrolysis gas passes through the aspiration pump and takes out pyrolysis device, realizes the separation of three-phase result.

(2) Pyrolysis oil and pyrolysis gas obtained by pyrolyzing waste tires are introduced into a garbage incinerator and are mixed with household garbage for combustion, sulfur in the pyrolysis oil gas is used for inhibiting generation of dioxin in the garbage incineration process, and generated heat is output in a high-parameter steam mode to perform efficient power generation. The pyrolysis product of the waste tyre and the tail gas generated by the combustion of the household garbage are treated together in a centralized way so as to reduce the emission of pollutants.

2. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the pyrolysis device is driven by a hollow screw rod, and the inside and the outside of the pyrolysis device are heated simultaneously.

3. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the pyrolysis temperature was 500 ℃.

4. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the garbage incinerator is a grate furnace.

5. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: and the pyrolysis-containing gas and the pyrolysis oil are respectively introduced into the grate furnace through the secondary fan and the rear wall of the hearth to be mixed and combusted.

6. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the sulfur-containing compound is inorganic hydrogen sulfide, organic thioether, thiophene and the like.

7. The process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the reaction mechanism of the sulfur dioxide for inhibiting the generation of precursor chlorine for generating dioxin is as follows:

8. the process method for pyrolysis of waste tires and coupled combustion of household garbage furnaces as claimed in claim 1, wherein the process method comprises the following steps: the reaction mechanism of sulfur dioxide poisoning the dioxin generation catalyst copper is as follows:

Technical Field

The invention relates to the technical field of solid waste disposal, in particular to a process method for optimizing a combustion process and inhibiting generation of dioxin in a waste incineration process by coupling waste tire pyrolysis products with household waste incineration.

Background

The garbage incineration power generation technology can realize harmless, resource and reduction treatment of household garbage, and is a main mode for treating the household garbage in various developed countries at present. However, the current household garbage combustion power generation technology has the problems of unstable combustion caused by low raw material heat value and insufficient garbage amount. Meanwhile, the domestic garbage inevitably generates secondary pollutants including polycyclic aromatic hydrocarbons, hydrogen chloride, dioxin and the like in the incineration process. Among them, dioxin is a generic name of chlorinated polynuclear aromatic compounds, is one of main pollutants generated in the incineration process of household garbage, and has strong toxicity. The emission limit value of dioxin in the incineration process of the household garbage is 0.1ng TEQ/m3 according to the pollution control Standard for incineration of the household garbage (GB18485-2014) in China. The method for controlling the emission of dioxin in waste incineration flue gas mainly comprises three methods, namely source control, process control and tail end control, wherein the process control refers to a method for adding an inhibitor into a furnace or optimizing waste incineration process parameters to inhibit the generation of dioxin, and the method has received extensive attention and research in recent years. The sulfur-containing compound, the nitrogen-containing compound and the basic compound are three main inhibitors, are widely applied to the garbage incinerator at present, and have excellent dioxin inhibiting effect. The sulfur-containing compound indirectly inhibits the generation of dioxin through inhibiting the formation of precursor chlorine and a way of poisoning a catalyst copper, so that the concentration of the dioxin in tail gas is reduced.

The waste tyre is a high-molecular thermosetting polymer, mainly comprises two elements of carbon and hydrogen, contains a small amount of elements of oxygen, nitrogen, sulfur and the like, has stable molecular structure, is difficult to naturally degrade, has complex raw material composition, often contains various additives, has strong heat resistance, biological resistance and mechanical resistance, can release a large amount of toxic carcinogenic pollutants when being directly burnt, and seriously pollutes the atmosphere. Among the various methods for disposing of scrap tires, pyrolysis technology is considered as the most highly resource-utilizing, less environmental pollution, and most sustainable disposal method. The pyrolysis of the waste tire refers to a process of destroying a cross-linking structure and chemical bonds of rubber in an inert atmosphere by heating and decomposing the rubber into products such as combustible gas, pyrolysis oil, pyrolysis carbon, steel wires and the like. Three-phase products obtained by pyrolysis have different utilization values, wherein the main components of pyrolysis gas are hydrogen, carbon monoxide, methane, ethane, ethylene, hydrogen sulfide and other small molecular gases, the main components of pyrolysis oil are hydrocarbon and a small amount of sulfur and nitrogen containing compounds, and the hydrocarbon and the small amount of sulfur and nitrogen containing compounds have high heat values and are good fuels.

By the method of feeding the waste tire pyrolysis product to the garbage incinerator for coupled combustion with the household garbage, the energy in the pyrolysis product can be recycled, the problem that the surplus pyrolysis product cannot be utilized to cause energy resource waste is solved, and meanwhile, the sulfur-containing compounds in the pyrolysis gas and the pyrolysis oil can be used as dioxin inhibitors to effectively inhibit the formation of dioxin in the household garbage incineration process.

Disclosure of Invention

The invention aims to provide a process method for pyrolysis of waste tires and coupled incineration of household garbage furnaces. The method solves the problem of excess capacity in the pyrolysis process of the waste tires, provides a new method for controlling dioxin in the waste incineration process, and has wide application prospect.

Description of the inventive principles:

(1) coupled combustion to optimize the combustion process principle: the problem of unstable combustion caused by insufficient garbage amount and low garbage heat value exists in the current garbage incineration process; the pyrolysis technology of the waste tires has the problems of excess productivity and unavailable products. Because the waste tire pyrolysis gas and the pyrolysis oil have high heat values and are introduced into the garbage furnace for combustion, part of heat can be provided, the problem of low heat value of household garbage is solved, the combustion efficiency of the garbage incinerator is improved, and the power generation output is improved.

(2) Coupled combustion to suppress dioxin generation principle: in the process of waste incineration, low-temperature heterogeneous catalytic reactions are considered as a main source of dioxin generation. The catalytic reaction has two key factors, namely precursor chlorine and catalyst bivalent copper. The role of sulfur in the dioxin generation process has two aspects: firstly, sulfur dioxide generated by sulfur combustion can react with chlorine and water to generate hydrogen chloride, so that chlorination is reduced, and generation of dioxin is inhibited; secondly, sulfur dioxide can poison the catalyst copper, namely, the sulfur dioxide reacts with copper to generate copper sulfate with low activity, so that the catalytic activity of the copper is reduced, and the generation of dioxin is indirectly inhibited. Vulcanization is one of the essential steps in the tire manufacturing process, and the purpose of vulcanization is to form an intermolecular crosslinked structure and enhance the tire performance. After the pyrolysis reaction of the waste tire, part of sulfur elements enter pyrolysis gas and pyrolysis oil. In the process of co-combustion of pyrolysis oil, gas and household garbage, sulfur dioxide generated by combustion of sulfur-containing compounds can effectively inhibit generation of dioxin.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

(1) and continuously feeding the waste tire particles into a pyrolysis furnace for pyrolysis in an inert atmosphere environment isolated from air, and obtaining three products of pyrolytic carbon black, pyrolytic oil and pyrolytic gas after pyrolysis reaction. The pyrolytic carbon falls into the collection bag by the action of gravity, and the pyrolysis oil is collected after passing through condensing equipment condensation, and pyrolysis gas passes through the aspiration pump and takes out pyrolysis device, realizes the separation of three-phase result.

(2) Pyrolysis oil and pyrolysis gas obtained by pyrolyzing the waste tires are introduced into a garbage incinerator and are mixed with household garbage for combustion, and heat is output in a high-parameter steam mode to carry out high-efficiency power generation. The pyrolysis product of the waste tire and the tail gas generated by the combustion of the household garbage are treated together in a centralized way so as to reduce the emission of waste gas.

The technical scheme of the invention utilizes pyrolysis oil, gas and household garbage generated by pyrolysis of waste tires to be coupled and combusted for power generation, and has the following unique advantages: on one hand, the pyrolysis product of the waste tire has high heat value, and the mixed combustion of the pyrolysis product and the household garbage can optimize the combustion process, improve the combustion efficiency of the garbage furnace and improve the power generation output of the garbage incinerator; on the other hand, the pyrolysis product of the waste tire contains a certain amount of sulfur-containing compounds, and the sulfur-containing compounds and the household garbage are mixed and combusted, so that the formation of dioxin in tail gas can be effectively inhibited.

According to the preferable scheme, the waste tire pyrolysis furnace adopts a push type screw device, so that efficient and continuous pyrolysis of waste tires can be realized.

According to the preferable scheme, the pyrolysis temperature of the waste tire is 500 ℃, the complete pyrolysis of the waste tire can be realized at the pyrolysis temperature, high-quality pyrolysis gas is obtained, and energy consumption waste caused by overhigh temperature is avoided.

According to the preferred scheme, the incinerator type is a grate incinerator, is a household garbage incinerator commonly used at present, and can be well coupled with waste tire pyrolysis gas for combustion.

In the preferred scheme, the pyrolysis gas and the pyrolysis oil are respectively introduced into the grate furnace through the secondary fan and the rear wall of the hearth to be mixed and combusted.

Compared with the prior art, the invention has the advantages that:

(1) the invention solves the problem of energy resource waste caused by unavailable utilization of redundant pyrolysis products generated by pyrolysis of waste tires, realizes the gradient utilization of energy and improves the overall utilization efficiency of energy.

(2) The invention couples the combustion of pyrolysis products of the waste tires and the household garbage, and utilizes the sulfur-containing compounds in the pyrolysis products to inhibit the generation of dioxin in the incineration process of the household garbage, thereby reducing the emission of the dioxin in tail gas.

Drawings

FIG. 1 is a flow chart of the process of pyrolysis and waste-oven coupled combustion of waste tires.

The sequence numbers in the figures illustrate: 1 a feed hopper; 2, a pyrolysis furnace; 3, a stock bin; 4, a circulating oil tank; 5, cooling the fan; 6, a first-stage heat exchanger; 7, an oil collecting tank; 8 circulating oil pump; 9 a secondary heat exchanger; 10 a pressure stabilizing tank; 11 pyrolysis oil; 12 pyrolysis gas; 13, hoisting a machine; 14 a primary air fan; 15 a secondary fan; 16 fire grates; 17 rear wall of the hearth; 18 water-cooled walls; 19 a scrap tire pyrolysis system; 20 waste incinerator system.

Detailed Description

The invention is further described in the following detailed description with reference to the drawings in which:

in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described with reference to the following examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Examples

The waste tire is crushed to the particle size of less than 1 cm, and is continuously fed into the pyrolysis furnace 2 through the feed hopper 1 for pyrolysis, and the temperature of the pyrolysis furnace 2 is set to be 500 ℃. After pyrolysis is finished, the pyrolytic carbon black falls into a bin 3 and is collected; the pyrolysis volatile component is condensed after passing through a primary heat exchanger 6 and a secondary heat exchanger 9, and the condensed pyrolysis oil 11 is collected in an oil collecting tank 7 and is sent into a garbage incinerator for mixed combustion through a hearth rear wall 17; the pyrolysis gas 12 is pumped out of the pyrolysis system by an air pump, stored in a pressure stabilizing tank 10 and sent into the waste incinerator for mixed combustion by a secondary fan 15. In order to realize the control and stable operation of pollutants of the household garbage incinerator, the amount of the pyrolysis gas and the pyrolysis oil entering the incinerator is changed along with the amount of garbage entering the incinerator and the heat value of the garbage. When the amount of the garbage fed into the furnace is reduced or the heat value of the garbage is reduced, the added pyrolysis gas and pyrolysis oil are added for afterburning; when the amount of garbage fed into the garbage incinerator is increased or the heat value of the garbage is increased, the input pyrolysis oil and pyrolysis gas are reduced, and the garbage incinerator is enabled to keep stable and efficient operation.

In the process, sulfur in the pyrolysis gas exists in the form of hydrogen sulfide, sulfur in the pyrolysis oil exists in the form of organic matters such as thioether and thiophene, and sulfur dioxide is generated after complete combustion.

The sulfur dioxide generates the following two reactions in the waste incineration process:

the reaction (1) converts chlorine gas, which is one of important precursors for generating dioxin, into hydrogen chloride, and indirectly suppresses the generation of dioxin by reducing the content of chlorine gas; reaction (2) converts copper oxide with high catalytic activity to copper sulfate with lower activity, and indirectly inhibits the formation of dioxin in a manner of poisoning the catalyst.