A combustion treatment device and process for nitrogen-containing raw materials

Abstract

The present invention discloses a multiphase combustion treatment device for nitrogen-containing raw materials, comprising a pyrolysis section and a combustion section connected as one body; a multi-media burner and a plurality of nitrogen-containing raw material inlets are respectively provided at one end of the pyrolysis section; a plurality of inlets are respectively provided on the multi-media burner for introducing high calorific value waste gas and waste liquid and air for combustion of high calorific value waste gas and waste liquid; the combustion section comprises a plurality of interconnected combustion chambers for completely burning pyrolysis products step by step; the other end of the pyrolysis section is connected to one of the combustion chambers. The present invention also provides a multiphase combustion treatment process for nitrogen-containing raw materials. The combustion treatment device and process of the present invention can especially perform integrated multiphase combustion for high-nitrogen three wastes, reduce the NOx conversion rate of raw nitrogen to below 5%, and control the flue gas oxygen content within 1% to 5%, reduce the flue gas volume and flue gas purification cost, and achieve better social and economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical processing, and relates to a multiphase combustion processing device and process for nitrogen-containing raw materials. Background Art

[0002] Some chemical companies or chemical parks need to treat solid waste, organic waste liquid and organic waste gas at the same time, and the composition of these solid waste, organic waste liquid and organic waste gas is complex, some of which have high calorific value and some of which have low calorific value. At present, the usual treatment method is to treat solid waste, waste liquid and waste gas with high calorific value and low calorific value separately, such as direct incineration of waste liquid and waste gas with high calorific value, and treatment of VOC waste gas with low calorific value by catalytic oxidation. This leads to the construction of several sets of incineration and disposal equipment for different three wastes in a park or a chemical plant, resulting in increased investment, increased land occupation and waste of resources.

[0003] Chinese patent document CN201920201760.7 discloses a comprehensive treatment system for gas, liquid and solid waste, which adopts a water-coal slurry process. However, its solid waste application scope is limited to high calorific value solid wastes such as coal, biomass, petroleum coke, blue carbon, sludge, oil sands, and waste activated carbon. Many additives need to be added during the preparation of coal slurry, which increases the incineration capacity of the incinerator. There are problems of limited adaptability and serious heat loss of slurry water.

[0004] Solid waste, waste liquid and waste gas of chemical enterprises often contain high ammonia nitrogen content. The traditional incineration process can control the conversion rate of ammonia nitrogen in the fuel to NOx to below 50% by combining a variety of low-nitrogen combustion technologies. For many organic wastes with high ammonia nitrogen content, a 50% conversion rate is still very high. The subsequent flue gas denitrification investment is large, the reagent consumption is large, and the operating cost is high.

[0005] Chinese patent document CN202010124361.2 discloses a low-nitrogen incineration technology for waste liquid and waste gas, in which the NO X The conversion rate can be controlled at around 10%, but for many high-nitrogen raw materials, a 10% conversion rate is still very high, and this method cannot treat solid waste, so it cannot solve the problem of comprehensive integrated ultra-low nitrogen disposal of solid waste, waste liquid and waste gas from high-nitrogen raw materials. Summary of the invention

[0006] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a multiphase combustion treatment device and process for nitrogen-containing raw materials, which can especially carry out integrated multiphase combustion of high raw material nitrogen three wastes, reduce the NOx conversion rate of raw nitrogen to below 5%, and control the flue gas oxygen content within 1% to 5%, thereby reducing the flue gas volume and flue gas purification costs, and achieving better social and economic benefits.

[0007] One of the purposes of the present invention is to provide a multiphase combustion processing device for nitrogen-containing raw materials, and the technical scheme adopted is as follows:

[0008] A multiphase combustion processing device for nitrogen-containing raw materials, comprising a pyrolysis section and a combustion section connected as one body;

[0009] A multi-medium burner and a plurality of nitrogen-containing raw material inlets are respectively provided at one end of the pyrolysis section; a plurality of inlets are respectively provided on the multi-medium burner for introducing high calorific value waste gas and waste liquid and air for combustion of high calorific value waste gas and waste liquid;

[0010] The combustion section comprises a plurality of interconnected combustion chambers for burning and purifying the pyrolysis products step by step; the other end of the pyrolysis section is connected to one of the combustion chambers.

[0011] Preferably, the pyrolysis section adopts a rotary pyrolysis furnace or a fixed pyrolysis furnace according to the type of nitrogen-containing raw materials. When the solid waste in the nitrogen-containing raw materials is easily grinded solid waste or does not contain solid waste, a fixed pyrolysis furnace is used to grind the easily grinded solid waste into particles of about 50 μm and then blown into the fixed pyrolysis furnace by a feeding fan; when the solid waste in the raw materials is ungrindable or difficult to grind, the solid waste is crushed into block particles below 10 cm and then fed into the rotary pyrolysis furnace via a feeding chute, a screw feeder, a pusher, or the like.

[0012] Preferably, the multi-media burner is fixed at one end of the rotary pyrolysis furnace or the fixed pyrolysis furnace.

[0013] Preferably, the multi-media burner is provided with a high calorific value waste liquid inlet, a high calorific value waste gas inlet, and a pyrolysis section primary air inlet.

[0014] Preferably, the nitrogen-containing raw material inlet includes any one or more of a solid waste inlet, a nitrogen-containing waste gas inlet, and a nitrogen-containing waste liquid inlet.

[0015] Preferably, the combustion section comprises a primary combustion chamber and a secondary combustion chamber which are internally connected, and the secondary combustion chamber is located on the upper side of the primary combustion chamber;

[0016] The primary combustion chamber is communicated with the other end of the pyrolysis section away from the medium burner.

[0017] Furthermore, a primary air inlet for the combustion section is provided at the bottom of the primary combustion chamber.

[0018] Furthermore, a fluidizing structure or a guide structure is provided at the bottom of the primary combustion chamber above the primary air inlet of the combustion section. The fluidizing structure is equipped with a fluidized bed material. When the nitrogen-containing raw material contains solid waste, a fluidizing structure is provided above the primary air inlet of the combustion section. The solid residue after pyrolysis collides strongly with the fluidized bed material and is crushed into fine particles, which helps the solid residue to burn completely. When the nitrogen-containing raw material does not contain solid waste, a guide structure is provided above the primary air inlet of the combustion section. The guide structure may be a guide plate or a guide grid, etc., to ensure that the primary air is evenly mixed with the pyrolysis product flue gas after pyrolysis in the pyrolysis section and the waste liquid, waste gas and waste water sent into the primary combustion chamber.

[0019] Furthermore, a plurality of external interfaces are provided on the outer wall of the primary combustion chamber, including any one or more combinations of a recycled flue gas interface, a low calorific value waste gas interface, a low calorific value waste liquid interface and a wastewater interface; wherein the flue gas of the combustion section escapes from the top and is connected to the recycled flue gas interface after heat recovery and purification.

[0020] Furthermore, a contraction-type mixing structure is provided at the inlet of the secondary combustion chamber, and the contraction-type mixing structure is located between the primary combustion chamber and the secondary combustion chamber; a combustion section secondary air interface is provided on the throat contraction section of the contraction-type mixing structure.

[0021] The second object of the present invention is to provide a multiphase combustion treatment process for nitrogen-containing raw materials, comprising the following steps:

[0022] S1. Solid waste materials and / or nitrogen-containing waste gas and / or nitrogen-containing waste liquid are respectively fed into the pyrolysis section through corresponding inlets for pyrolysis treatment. At the same time, high calorific value waste gas and waste liquid and primary air of the pyrolysis section are burned through a multi-media burner to provide heat for high-temperature pyrolysis of nitrogen-containing raw materials in the pyrolysis section;

[0023] S2. The pyrolysis products of the pyrolysis section enter the multiple combustion chambers of the combustion section, and are burned and purified step by step. The smoke after complete combustion escapes from the top of the combustion section.

[0024] Preferably, in step S2, the combustion section includes a primary combustion chamber, a contraction mixing structure, and a secondary combustion chamber arranged in sequence from bottom to top;

[0025] The pyrolysis product first enters the primary combustion chamber, and primary air is introduced into the bottom of the primary combustion chamber through the primary air inlet of the combustion section. At the same time, the waste water and / or low calorific value waste gas and / or low calorific value waste liquid introduced from the outside are converted into gaseous substances in the primary combustion chamber by the high temperature of the pyrolysis product, and then are evenly mixed with the pyrolysis product and the primary air, so that the waste water and / or low calorific value waste gas and / or low calorific value waste liquid and the pyrolysis product are fully burned in the primary combustion chamber, and the smoke after combustion escapes to the contraction mixing structure;

[0026] Wherein, when the nitrogen-containing raw materials in step S1 include solid waste materials, nitrogen-containing waste gas and nitrogen-containing waste liquid: the pyrolysis product first enters the primary combustion chamber, and the solid residue after pyrolysis is fluidized by the primary air on the fluidized bed at the bottom of the primary combustion chamber, and at the same time, it collides strongly with the bed material on the fluidized bed to form fine particles, so that the solid residue after pyrolysis is completely burned at the bottom. The high-temperature flue gas after pyrolysis is mixed with the wastewater and / or low calorific value waste liquid and / or low calorific value waste gas introduced from the outside in the primary combustion chamber, and the low calorific value waste liquid and / or waste water evaporates rapidly and is evenly mixed with the low calorific value waste gas, the flue gas and the primary air introduced from the bottom of the primary combustion chamber, so that the pyrolysis products and the low calorific value waste gas and waste liquid are fully burned in the primary combustion chamber, and then escape to the contraction mixing structure;

[0027] In addition, a secondary air interface for the combustion section is provided on the throat contraction section of the contraction mixing structure. The secondary air and the flue gas from the primary combustion chamber are strongly mixed at the contraction mixing structure and then flow upward into the secondary combustion chamber, so that the unreacted combustibles in the pyrolysis section and the primary combustion chamber are completely burned in the secondary combustion chamber, and then the flue gas escapes from the top of the secondary combustion chamber.

[0028] Furthermore, in step S1, the amount of primary air in the pyrolysis section is controlled to keep the air-fuel ratio in the pyrolysis section between 0.6 and 0.9 and the temperature between 1200°C and 1350°C, and the nitrogen in the raw material is controlled to be converted into N2 according to the reduction mechanism. The pyrolysis temperature is controlled above 1200°C to ensure that NH3 with a higher activation energy is completely reacted. However, if the reaction temperature is too high, exceeding 1350°C, it will not only have little contribution to the conversion rate of NH3, but also cause the subsequent combustion furnace temperature to be too high, and the thermodynamic NOx production will increase. High investment cost of incinerator , .

[0029] Furthermore, in step S2, the temperature in the primary combustion chamber is maintained at 950°C to 1200°C by controlling the amount of waste water and / or low calorific value waste liquid and / or low calorific value waste gas and / or recycled flue gas and the amount of primary air.

[0030] Furthermore, in step S2, the temperature in the secondary combustion chamber is maintained at 850° C. to 1100° C. and the oxygen content is maintained at 1% to 5% by controlling the amount of secondary air.

[0031] The present invention can bring the following beneficial effects:

[0032] 1) In the present invention, the pyrolysis section is combined with the combustion section. The pyrolysis section burns high calorific value waste liquid and waste gas through a multi-media burner, and provides sufficient oxygen for its combustion process, thereby providing the high temperature required by the pyrolysis section. The specific temperature control is adjusted according to the composition of the three wastes of gas, liquid and solid to be treated, so as to achieve sufficient pyrolysis of different phase substances (which can be multi-phase substances, of course, can also be single-phase substances). However, the pyrolysis section as a whole is in an oxygen-deficient reduction state, so the pyrolysis of its solid waste, waste liquid and waste gas produces a large amount of reducing gases such as CO, H2, hydrocarbons, etc., thereby inhibiting the conversion of ammonia nitrogen in the raw material into nitrogen oxides. At the same time, the generated nitrogen oxides and the nitrogen oxides carried by the waste gas itself are reduced to nitrogen at high temperature. The solid residues and gas products after treatment in the pyrolysis section enter the combustion section. By adopting a multi-combustion chamber structure, the pyrolysis products can be subjected to sufficient deep reaction treatment in stages. Therefore, by integrating the advantages of pyrolysis and combustion, the NOx conversion rate of raw nitrogen in waste gas, waste liquid and solid waste can be greatly reduced, low-nitrogen treatment of nitrogen-containing raw materials, especially high-nitrogen raw materials, can be achieved, the NOx concentration at the incinerator outlet can be reduced, and the subsequent flue gas denitrification treatment equipment and operating costs can be reduced.

[0033] 2) The present invention can not only process waste gas, waste liquid and waste water of various calorific values ​​and compositions, but also process various solid wastes at the same time, and has a very strong raw material adaptability. Therefore, it realizes integrated multi-phase pyrolysis combustion for high-nitrogen raw materials, three wastes, with high integration and cost saving, and is suitable for industrial promotion.

[0034] 3) The present invention combines process conditions to ensure that the NOx conversion rate of the raw nitrogen in the waste gas, waste liquid and solid waste is less than 5%, and the efficiency of reducing NOx in the raw waste gas to N2 is above 95%. Thus, the NOx concentration at the outlet of the incinerator can be greatly reduced, and the subsequent flue gas denitrification treatment equipment and operating costs can be reduced.

[0035] 4) In the present invention, through step-by-step pyrolysis combustion, complete combustion under low-oxygen combustion can be ensured, and the oxygen content of the flue gas escaping from the secondary combustion chamber is controlled within 1% to 5%, thereby reducing the flue gas volume and flue gas purification costs, and achieving better social and economic benefits.

[0036] 5) The present invention provides a pyrolysis section and multiple combustion chambers, and can select suitable functional parts for processing according to the characteristics of organic matter, thereby ensuring complete combustion of raw organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of the processing device of the present invention.

[0038] The meaning of the symbols in the figure:

[0039] 1-pyrolysis section, 11-multi-media burner, 12-solid waste inlet, 13-nitrogen-containing waste gas inlet, 14-nitrogen-containing waste liquid inlet, 15-high calorific value waste liquid inlet, 16-high calorific value waste gas inlet, 17-pyrolysis section primary air inlet, 2-combustion section, 20-primary combustion chamber, 21-combustion section primary air inlet, 22-fluidizing device, 23-recirculating flue gas inlet, 24-wastewater inlet, 25-low calorific value waste liquid inlet, 26-low calorific value waste gas inlet, 27-contraction mixing device, 28-combustion section secondary air inlet, 29-secondary combustion chamber. DETAILED DESCRIPTION

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0041] In order to simplify the drawings, each figure only schematically shows the parts related to the present invention, which do not represent the actual structure of the product.

[0042] According to an embodiment provided by the present invention, Figure 1 As shown, a multiphase combustion processing device for nitrogen-containing raw materials includes a pyrolysis section 1 and a combustion section 2 connected as one body;

[0043] One end of the pyrolysis section 1 is provided with a multi-media burner 11 and a plurality of nitrogen-containing raw material inlets; the multi-media burner 11 is provided with a plurality of inlets for introducing high calorific value waste gas and waste liquid and air for combustion of the high calorific value waste gas and waste liquid;

[0044] The combustion section 2 includes a plurality of interconnected combustion chambers for gradually burning and purifying the pyrolysis products; the other end of the pyrolysis section 1 is connected to one of the combustion chambers.

[0045] In this embodiment, the pyrolysis section is combined with the combustion section. The pyrolysis section burns high calorific value waste liquid and waste gas through a multi-media burner and provides sufficient oxygen for its combustion process, thereby providing the high temperature required by the pyrolysis section. The specific temperature control is adjusted according to the composition of the three wastes of gas, liquid and solid to be treated, so as to achieve sufficient pyrolysis of materials in different phases. However, since the pyrolysis section is also provided with a nitrogen-containing raw material inlet, wherein a plurality of nitrogen-containing raw material inlets can be connected to raw material inlets of different phases (including gas, liquid and solid), such as a solid waste inlet 12, a nitrogen-containing waste gas inlet 13, and a nitrogen-containing waste liquid inlet 14, according to the different forms of solid waste (referred to as "solid waste"), the solid waste can be fed into the pyrolysis section 1 through a feeding chute or a screw feeder or a powder injection or a pusher, and the nitrogen-containing waste liquid is atomized by a spray gun and then fed into the pyrolysis section 1. The nitrogen-containing waste gas is sent into the pyrolysis section 1 together with the solid waste or mixed with the solid waste. The nitrogen-containing waste gas is sent into the pyrolysis section 1 by a spray gun or a distributor. After the nitrogen-containing raw material is introduced, the pyrolysis section 1 is in an oxygen-deficient reduction state as a whole. Therefore, the pyrolysis of solid waste, waste liquid, waste gas, etc. produces a large amount of reducing gases such as CO and H2. Inside the pyrolysis section 1, the amino and nitro groups in the high-nitrogen waste liquid and solid waste, as well as NOx and NH3 in the high-nitrogen waste gas, react with reducing gases such as CO and H2 to generate N2 and H2O. That is, the pyrolysis of solid waste produces a large amount of reducing gases such as CO, H2, and hydrocarbons, thereby inhibiting the conversion of ammonia nitrogen in the raw material into nitrogen oxides. At the same time, the generated nitrogen oxides and the nitrogen oxides carried by the waste gas itself are reduced to nitrogen at high temperature. The residue (including solid residue) after treatment in the pyrolysis section 1 enters the combustion section. By adopting a multi-combustion chamber structure, the pyrolysis products can be subjected to sufficient deep reaction treatment in stages. Therefore, by integrating the advantages of pyrolysis and combustion, the NOx conversion rate of raw nitrogen in waste gas, waste liquid and solid waste can be greatly reduced, the NOx concentration at the incinerator outlet can be reduced, and the subsequent flue gas denitrification treatment equipment and operating costs can be reduced.

[0046] As a preferred embodiment, the pyrolysis section 1 adopts a rotary pyrolysis furnace, and the multi-media burner 11 is fixed at one end of the rotary pyrolysis furnace. Specifically, the rotary pyrolysis furnace can be fed by a feeding chute or a screw feeder or a pusher, and is suitable for various solid wastes with a particle size of less than 10 cm or semi-solid wastes with high water content. Thus, the rotary pyrolysis furnace can fully mix the flue gas and solid waste in the furnace by rotation, ensuring that the solid waste is completely pyrolyzed and the nitrogen oxides in the flue gas are fully reduced. More preferably, the cylinder of the rotary pyrolysis furnace can rotate around its own axis, and a disturbance structure can be set in the cylinder to strengthen the turning of the solid waste and promote its mixing with the high-temperature pyrolysis flue gas. In the process of rotation, the flue gas and solid waste can be further mixed in the furnace more fully, deeply promoting the pyrolysis of solid waste and the reduction of nitrogen oxides in the flue gas. Of course, in some application scenarios, the pyrolysis section 1 can also adopt a fixed pyrolysis furnace. For example, when there is no solid waste raw material, no residue will be produced due to pyrolysis, and the gas formed by the pyrolysis of gas and liquid phase materials in the pyrolysis furnace can be spontaneously mixed and evenly mixed.

[0047] As another preferred embodiment, the multi-media burner 11 is provided with a high calorific value waste liquid inlet 15, a high calorific value waste gas inlet 16, and a pyrolysis section primary air inlet 17. Specifically, the high calorific value waste liquid inlet 15 is connected to a high calorific value waste liquid spray gun, so that the high calorific value waste liquid is atomized by the spray gun and then sent to the pyrolysis section 1 for combustion; the high calorific value waste gas inlet 16 is connected to a high calorific value waste gas spray gun or a distributor and sent to the pyrolysis section 1 for combustion; the pyrolysis section primary air inlet 17 is used to introduce combustion air; the high calorific value waste gas and waste liquid are burned through the multi-media burner under the action of the pyrolysis section primary air to provide heat for the pyrolysis section, so that the pyrolysis temperature is maintained above 1200°C while being controlled not to exceed 1350°C, thereby promoting pyrolysis efficiency.

[0048] Therefore, the pyrolysis in the pyrolysis section 1 is actually a three-phase pyrolysis of gas, liquid and solid. The combustion of high calorific value waste gas and waste liquid provides heat for pyrolysis. High nitrogen waste gas, high nitrogen waste liquid and solid waste can be pyrolyzed in the pyrolysis section 1 in the three-phase state of gas, liquid and solid; the combustion section 2 is actually a three-phase combustion of gas, liquid and solid, including the combustion of pyrolysis flue gas, the combustion of low calorific value waste gas / waste liquid and the combustion of pyrolysis solid residue. Specifically, according to the needs, any one or more phases of mixed combustion treatment can be selected.

[0049] As another preferred embodiment, the combustion section 2 includes a primary combustion chamber 20 and a secondary combustion chamber 29 which are internally connected, and the secondary combustion chamber 29 is located on the upper side of the primary combustion chamber 20; the primary combustion chamber 20 is interconnected with the other end of the pyrolysis section 1 away from the medium burner 11.

[0050] Specifically, a combustion section primary air inlet 21 is provided at the bottom of the primary combustion chamber 20. More preferably, a fluidizing structure 22 or a flow guide structure is further provided at the bottom of the primary combustion chamber 20 above the combustion section primary air inlet 21. The fluidizing structure 22 is equipped with a fluidized bed material. When the nitrogen-containing raw material contains solid waste, the fluidizing structure 22 is arranged above the combustion section primary air inlet 21. The solid residue after pyrolysis collides strongly with the fluidized bed material and is crushed into fine particles, which helps to completely burn the solid residue. By adopting a fluidizing structure at the bottom of the primary combustion chamber 20 and introducing primary air from the combustion section primary air inlet 21, the functions of the primary air include burning out and fluidizing the solid particles after pyrolysis. The solid particles after pyrolysis are completely burned in the fluidized area of ​​the primary combustion chamber, and the ash loss rate is less than 3%. When there is no solid waste in the nitrogen-containing raw material, a guide structure is set above the primary air inlet 21 of the combustion section. The guide structure can be a guide plate or a guide grid, etc., to ensure that the primary air is evenly mixed with the pyrolysis product flue gas after pyrolysis in the pyrolysis section 2 and the waste liquid and / or waste gas and / or waste water sent into the primary combustion chamber 20.

[0051] More specifically, an external interface is provided on the outer wall of the primary combustion chamber 20, including any one or more combinations of a recycled flue gas interface 23, a low calorific value exhaust gas interface 26, a low calorific value waste liquid interface 25 and a wastewater interface 24; wherein the flue gas of the combustion section 2 escapes from the top to an external device for treatment, and then is recycled and connected to the recycled flue gas interface 23.

[0052] In this embodiment, since the primary combustion chamber 20 has reducing gases such as CO, H2 and solid residues from the pyrolysis section 1 to burn, its temperature is very high; the pyrolysis solid residues sent from the pyrolysis section 1 are blown up by the primary air in the fluidized structure 22 and the fluidized bed material to form a fluidized state, and collide with the fluidized bed material to be broken into fine particles, and undergo a strong combustion chemical reaction with the primary air supporting combustion at high temperature, the solid residue incineration rate is high, the ash ignition rate is less than 3%, and most of the fly ash after combustion is carried out of the combustion section 2 by the combustion flue gas. At the same time, the recycled flue gas and / or waste water and / or low calorific value waste liquid and / or low calorific value waste gas introduced from the outside are rapidly evaporated and decomposed in the primary combustion chamber 20, which is not only conducive to controlling the temperature of the primary combustion chamber 20 and the complete combustion of organic matter, but also effectively treats a variety of chemical waste gas raw materials, indicating that the adaptability of raw material treatment is very strong. For example, the temperature of the primary combustion chamber 20 is controlled to be 950°C to 1200°C (the specific control temperature is adjusted according to the composition of the three wastes of gas, liquid and solid to be treated). In addition, it should be noted that when the material delivered from the pyrolysis section 2 does not contain solid components, the fluidization structure 22 can be omitted.

[0053] Among them, it should be noted that the recirculated flue gas is the flue gas escaping from the top of the combustion section 2, which is processed by external equipment and then recycled to the recirculated flue gas interface 23. The low calorific value exhaust gas interface 26, the low calorific value waste liquid interface 25 and the waste water interface 24 are all introduced from the outside. The corresponding waste gas, waste liquid and waste water can be selectively configured according to the needs of different projects. For example, if there is no low calorific value exhaust gas in some application scenarios, there is no need to set up a low calorific value exhaust gas interface 26. Of course, other interfaces of different phases can also be set on the outer wall of the primary combustion chamber 20 according to needs to pass different raw materials.

[0054] Furthermore, a contraction-type mixing structure 27 is connected to the entrance of the secondary combustion chamber 29, and the contraction-type mixing structure 27 is located between the primary combustion chamber 20 and the secondary combustion chamber 29; a combustion section secondary air interface 28 is provided on the throat contraction section of the contraction-type mixing structure 27. That is, the contraction-type mixing structure 27 is located at the upper part of the external interface of the primary combustion chamber 20 (recirculating flue gas interface 23, low calorific value waste gas interface 26, low calorific value waste liquid interface 25 and waste water interface 24, etc.), ensuring that external raw materials such as low calorific value waste gas and waste liquid first pass through the primary combustion chamber, and then enter the secondary combustion chamber through the contraction-type mixing structure for step-by-step full combustion treatment. In this embodiment, the contraction-type mixing structure 27 is connected between the primary combustion chamber 20 and the secondary combustion chamber 29, respectively, so that the pyrolysis products of the pyrolysis section 1 are sent into the primary combustion chamber 20, and the products after the combustion treatment continue to shrink and mix with the supplemented combustion section secondary air before entering the secondary combustion chamber 29 for full combustion treatment. Specifically, through the throat effect of the contraction section, the secondary air and the flue gas from the primary combustion chamber 20 are strongly mixed at the contraction mixing structure 27 and then enter the secondary combustion chamber 29 upward, which can ensure uniform mixing at the microscopic scale and reduce the flue gas temperature, so that the temperature in the secondary combustion chamber 29 is 850°C ~ 1100°C (the specific control temperature is adjusted according to the composition of the waste gas and waste liquid being treated), and the secondary combustion chamber 29 is provided with sufficient flue gas retention space to ensure the complete combustion reaction of the combustible material.

[0055] According to another embodiment of the present invention, a multiphase combustion process for nitrogen-containing raw materials is provided, combining Figure 1 As shown, the following steps are included:

[0056] S1, solid waste materials and / or nitrogen-containing waste gas and waste liquid are respectively sent to the pyrolysis section 1 through the corresponding inlets for pyrolysis treatment. At the same time, high calorific value waste gas and waste liquid and primary air of the pyrolysis section are sent to the pyrolysis section for combustion through the multi-media burner 11 to provide heat for the high-temperature pyrolysis of the nitrogen-containing raw materials in the pyrolysis section 1;

[0057] S2. The pyrolysis products of pyrolysis section 1 enter the multiple combustion chambers of combustion section 2, and are burned and purified step by step. The purified flue gas escapes from the top of the combustion section.

[0058] In this embodiment, the pyrolysis section 1 is combined with the combustion section 2. The pyrolysis section 1 burns the high calorific value waste liquid and waste gas through the multi-media burner 11, and provides sufficient oxygen for its combustion process, thereby providing the high temperature required by the pyrolysis section. The specific temperature control is adjusted according to the composition of the gas, liquid and solid wastes to be treated, so as to achieve sufficient pyrolysis of different phase substances. However, since solid waste materials, high nitrogen waste gas and waste liquid are introduced into the pyrolysis section through the solid waste inlet 12, the nitrogen-containing waste gas inlet 13 and the nitrogen-containing waste liquid inlet 14, the pyrolysis section 1 is in an oxygen-deficient reduction state as a whole, so the solid waste, waste liquid and waste gas therein are pyrolyzed to release a large amount of reducing gases such as CO and H2. Inside the pyrolysis section 1, the amino and nitro groups in the high nitrogen waste liquid and solid waste, and the NOx and NH3 in the high nitrogen waste gas react with reducing gases such as CO and H2 to generate N2 and H2O. The residue after the pyrolysis stage 1 enters the combustion stage. By adopting a multi-combustion chamber structure, the pyrolysis products can be fully reacted and treated in stages. Therefore, by integrating the advantages of pyrolysis and combustion and combining process parameter control, the NOx conversion rate of the raw nitrogen in the waste gas, waste liquid and solid waste can be guaranteed to be less than 5%, and the efficiency of reducing NOx in the raw waste gas to N2 is above 95%. This process can greatly reduce the NOx concentration at the outlet of the incinerator, and reduce the subsequent flue gas denitrification treatment equipment and operating costs. It can greatly reduce the NOx conversion rate of the raw nitrogen in the waste gas, waste liquid and solid waste, reduce the NOx concentration at the outlet of the incinerator, and reduce the subsequent flue gas denitrification treatment equipment and operating costs.

[0059] In actual application, in step S1, different forms of pyrolysis furnaces are selected for the pyrolysis section according to whether the nitrogen-containing raw material to be processed contains solid waste; when the processed nitrogen-containing raw material contains solid waste, a rotary pyrolysis furnace is used, and the solid waste is rotated along with the pyrolysis furnace cylinder to enhance the pyrolysis of the solid waste; when the raw material does not contain solid waste, a fixed pyrolysis furnace is used to reduce the project cost.

[0060] As a preferred embodiment, in step S2, the combustion section 2 includes a primary combustion chamber 20, a contraction mixing structure 27, and a secondary combustion chamber 29 arranged in sequence from bottom to top;

[0061] The pyrolysis product first enters the primary combustion chamber 20, and primary air is introduced through the primary air inlet 21 of the combustion section at the bottom of the primary combustion chamber 20. At the same time, the waste water and / or low calorific value waste gas and / or low calorific value waste liquid introduced from the outside are converted into gaseous substances in the primary combustion chamber 20 by the high temperature of the pyrolysis product, and then mixed with the pyrolysis product and the primary air, so that the waste water and / or low calorific value waste gas and / or low calorific value waste liquid and the pyrolysis product are fully burned in the primary combustion chamber, and the smoke after combustion escapes to the contraction mixing structure 27;

[0062] Wherein, when the nitrogen-containing raw materials in step S1 include solid waste materials, nitrogen-containing waste gas, and nitrogen-containing waste liquid: the pyrolysis product first enters the primary combustion chamber 20, and the solid residue after pyrolysis is fluidized by the primary air introduced on the fluidized bed material at the bottom of the primary combustion chamber 20, and at the same time, it is strongly collided with the fluidized bed material to become fine particles, so that the solid residue after pyrolysis is completely burned at the bottom. The high-temperature flue gas after pyrolysis is mixed with the waste water and / or low calorific value waste liquid and / or low calorific value waste gas introduced from the outside in the primary combustion chamber 20, and the low calorific value waste liquid and / or waste water evaporates rapidly and is evenly mixed with the low calorific value waste gas, the flue gas, and the primary air introduced from the bottom of the primary combustion chamber 20, so that the pyrolysis product and the low calorific value waste gas and waste liquid are fully burned in the primary combustion chamber 20, and then escape to the contraction mixing structure 27;

[0063] In addition, a combustion section secondary air interface 28 is provided on the throat contraction section of the contraction mixing structure 27. The secondary air and the flue gas from the primary combustion chamber 20 are strongly mixed at the contraction mixing structure 27 and then enter the secondary combustion chamber 29 upward, so that the unreacted combustibles such as CO in the pyrolysis section 1 and the primary combustion chamber 20 are completely burned in the secondary combustion chamber 29, and then the flue gas escapes from the top of the secondary combustion chamber 29.

[0064] Among them, since the primary combustion chamber 20 is mainly used for the combustion of pyrolysis products and residual carbon, the combustion temperature is very high, and the low calorific value waste gas and / or low calorific value waste liquid and / or waste water will be quickly evaporated and decomposed in the primary combustion chamber 20, which is conducive to controlling the temperature of the primary combustion chamber 20 and the full combustion of organic matter. More preferably, a fluidizing structure 22 is set above the primary air inlet 21 at the bottom of the primary combustion chamber 20, so that the bottom of the fluidizing structure 22 passes through the primary air inlet 21 to enter the primary combustion chamber 20, so that the solid particles after pyrolysis such as residual carbon can be completely burned in the primary combustion chamber 20, and the ash ignition reduction rate is less than 3%.

[0065] In addition, the flue gas escaping from the top of the secondary combustion chamber 29 can be connected to the recirculating flue gas interface 23 after being processed by external equipment, and then enter the primary combustion chamber for deep combustion processing.

[0066] More preferably, in step S1, the primary air volume of the pyrolysis section is controlled so that the air-fuel ratio in the pyrolysis section 1 is maintained between 0.6 and 0.9 and the temperature is above 1200° C. The temperature is preferably between 1200° C. and 1350° C., and the specific temperature control is adjusted according to the composition of the three wastes of gas, liquid and solid to be processed, thereby inhibiting the conversion of ammonia nitrogen in the raw material into NOx and converting the NOx contained in the waste gas itself into N2.

[0067] More preferably, in step S2, the temperature in the primary combustion chamber is maintained at 950° C. to 1200° C. by controlling the amount of wastewater, low calorific value waste liquid, low calorific value waste gas, recycled flue gas and primary air. The specific temperature control is adjusted according to the composition of the three wastes of gas, liquid and solid to be processed.

[0068] More preferably, in step S2, the temperature in the secondary combustion chamber 29 is maintained at 850°C ~ 1100°C by controlling the amount of secondary air, and the specific temperature control is adjusted according to the composition of the waste gas and waste liquid being treated; the oxygen content in the secondary combustion chamber 29 is maintained at 1% ~ 5%, and the specific oxygen content is adjusted according to the composition of the gas, liquid and solid wastes being treated.

[0069] For the processing device and process provided in the above embodiments, specific project tests are carried out to form the following embodiments:

[0070] Example 1 Comprehensive treatment project of gas, liquid and solid wastes in a chemical plant

[0071] Raw materials: The combustion raw materials include 2 kinds of solid wastes, 3 kinds of waste liquids, and 1 kind of waste gas. The total nitrogen content of the raw materials is 2.67%wt (calculated as N, excluding N2 content).

[0072] Solid waste 1: solid tar

[0073] Solid waste 2: Waste activated carbon

[0074] Waste liquid 1: Acrylonitrile waste liquid (containing 5.4%wt C3H5N, the rest is water)

[0075] Waste liquid 2: Crude acrylonitrile liquid (containing 49.13%wt C2H3N, 0.59%wt C3H3N, 2.28%wt HCN, the rest is water)

[0076] Waste liquid 3: Hydrocyanic acid (containing 99.6% wt HCN, the rest is water)

[0077] Waste gas 1: Absorption tower discharges air (containing 58mg / Nm 3 C3H3N, 926mg / Nm 3 NO2, 88.34%wt N2, 1.03%wt CO, the rest are inert gases, oxygen, water)

[0078] Combustion treatment device: The device of the present invention is adopted, the pyrolysis section adopts a rotary pyrolysis furnace, the combustion section adopts two combustion chambers to form two-stage combustion, and the primary combustion chamber adopts fluidized bed combustion.

[0079] Feeding: Solid waste 1 and solid waste 2 are fed into the rotary pyrolysis furnace through the solid waste inlet 12 by the feeder, high nitrogen waste liquids 1, 2, and 3 are fed into the pyrolysis section through the waste liquid spray gun through the nitrogen-containing waste liquid inlet 14, and high nitrogen waste gas 1 is fed into the pyrolysis section through the waste gas distributor through the nitrogen-containing waste gas inlet 13. A supplementary combustion burner is also provided in the pyrolysis section. Here, the function of the supplementary combustion burner is to preheat and supplement the pyrolysis furnace when starting (when the pyrolysis temperature is insufficient). The waste liquid and waste gas that are easy to burn are fed in through the multi-media burner, and the waste liquid and waste gas that are not easy to burn are fed into the pyrolysis furnace separately through the supplementary combustion burner. Since waste liquids 1 and 2 contain a lot of water, waste liquid 3 is not easy to burn, and the calorific value of waste gas 1 is very low, a supplementary combustion burner is provided separately to promote combustion in the pyrolysis section. The primary combustion chamber of the combustion section is provided with a primary air inlet 21 of the combustion section and a recirculating flue gas interface 23, and the contraction mixing structure 27 at the entrance of the secondary combustion chamber 29 is provided with a secondary air inlet 28 of the combustion section.

[0080] Combustion treatment process: pyrolysis temperature is controlled at 1250-1280°C, the air-fuel ratio of the pyrolysis section is 0.85, the temperature of the primary combustion chamber is controlled at 1100-1120°C, and the temperature of the secondary combustion chamber is controlled at 950-1000°C.

[0081] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 220mg / Nm 3 The outlet oxygen concentration is about 3.1%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.83%.

[0082] Example 2: Comprehensive treatment project of gas, liquid and solid wastes in a chemical plant

[0083] Raw materials: Same as Example 1.

[0084] Combustion treatment device: Same as Example 1.

[0085] Feed: Same as Example 1.

[0086] Combustion treatment process: The pyrolysis temperature is controlled at 1200-1250°C, the air-fuel ratio of the pyrolysis section is 0.85, the temperature of the primary combustion chamber is controlled at 1050-1100°C, and the temperature of the secondary combustion chamber is controlled at 900-950°C.

[0087] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 185mg / Nm 3 The outlet oxygen concentration is about 3.2%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.70%.

[0088] Example 3: Comprehensive treatment project of gas, liquid and solid wastes in a chemical plant

[0089] Raw materials: Same as Example 1.

[0090] Combustion treatment device: Same as Example 1.

[0091] Feeding: Solid waste 1 and solid waste 2 are fed into the rotary pyrolysis furnace through the solid waste inlet 12 by the feeder, and high-nitrogen waste liquids 1, 2, and 3 are fed into the pyrolysis section through the waste liquid spray gun and the nitrogen-containing waste liquid inlet 14. The pyrolysis section is also provided with a supplementary burner. The primary combustion chamber of the combustion section is provided with a combustion section primary air inlet 21 and an exhaust gas 1 interface (high-nitrogen exhaust gas 1 is fed into the primary combustion chamber through the exhaust gas 1 interface), and the contraction mixing structure 27 at the entrance of the secondary combustion chamber 29 is provided with a combustion section secondary air inlet 28.

[0092] Combustion treatment process: The pyrolysis temperature is controlled at 1250-1280°C, the air-fuel ratio of the pyrolysis section is 0.7, the temperature of the primary combustion chamber is controlled at 1050-1100°C, and the temperature of the secondary combustion chamber is controlled at 900-950°C.

[0093] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 430mg / Nm 3 The outlet oxygen concentration is about 4.3%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 1.62%.

[0094] Example 4: Comprehensive treatment project of gas, liquid and solid wastes in a chemical plant

[0095] Raw materials: Same as Example 1.

[0096] Combustion treatment device: Same as Example 1.

[0097] Feed: Same as Example 3.

[0098] Combustion treatment process: pyrolysis temperature is controlled at 1250-1280°C, the air-fuel ratio of the pyrolysis section is 0.7, the temperature of the primary combustion chamber is controlled at 1050-1065°C, and the temperature of the secondary combustion chamber is controlled at 950-1000°C.

[0099] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 300mg / Nm 3 The outlet oxygen concentration is about 3.2%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 1.13%.

[0100] Example 5: Comprehensive treatment project of gas, liquid and solid wastes in a chemical plant

[0101] Raw materials: including 1 type of solid waste, 5 types of waste liquids, and 3 types of waste gases. The total nitrogen content of the raw materials is 2.34%wt (calculated as N, excluding N2 content).

[0102] Solid waste 1: sludge (water content 70%, ammonia nitrogen 2000mg / kg)

[0103] Waste liquid 1: DMC purified light components (containing 41.95%wt MF, 49.14%wt ML, 8.4%wt ME, 0.51%wt DMC)

[0104] Waste liquid 2: DMC purified heavy components (containing 60%wt DMC, 40%wt DMO)

[0105] Waste liquid 3: ethylene glycol light component (containing 20.74%wt methyl glycolate, 30.99%wt butanediol, 27.57%wt ethylene glycol, 0.01%wt diethylene glycol, and the rest is water)

[0106] Waste liquid 4: Ethylene glycol heavy component (containing 67.94%wt ethylene glycol, 14.26%wt triethylene glycol, 11.7%wt propylene glycol, 2.42%wt diethylene glycol, 3.68%wt ethylene carbonate)

[0107] Waste liquid 5: ethanol tower wastewater (containing 4.78%wt amyl alcohol, 10.88%wt ethylene glycol, 0.34%wt ethanol, 0.26%wt n-propanol, 1.13%wt butanol, 0.7%wt ethylene glycol monomethyl ether, and the rest is water)

[0108] Waste gas 1: MN recovery tower vent air (containing 1.25%wt methyl nitrite, 2.96%wt NO, 1.2%wt N2O, 0.63%wt ML, 0.83%wt ME, 12.42%wt CO, the rest is inert gas N2 and CO2)

[0109] Waste gas 2: Shift stripping tower acid gas components (containing 22.5% wt ammonia, 14.32% wt H2S, 0.01% wt H2, 0.05% wt CO, the rest is CO2 and water vapor)

[0110] Waste gas 3: DMC device waste gas (containing 42.81%wt methyl nitrite, 1.08%wt NO, 2.47%wt N2O, 0.69%wt CO, 1.48%wt CH3Cl, 4.04%wt DME, 7.52%wt ML, the rest is N2, CO2 and water vapor)

[0111] Combustion treatment device: The device of the present invention is adopted, that is, the pyrolysis section adopts a rotary pyrolysis furnace, the combustion section adopts two combustion chambers to form two-stage combustion, and the primary combustion chamber adopts fluidized bed combustion.

[0112] Feeding: solid waste 1 is fed into the rotary pyrolysis section through a feeder, high calorific value waste liquids 1, 2, 3, and 4 are fed into the pyrolysis section through the waste liquid spray gun on the multi-media burner panel, and high nitrogen waste gases 1, 2, and 3 are fed into the pyrolysis section through a waste gas distributor. The primary combustion chamber of the combustion section is provided with a combustion section primary air inlet 21, a recirculating flue gas interface 23, and a waste liquid 5 interface (waste liquid 5 is fed into the primary combustion chamber), and a combustion section secondary air inlet 28 is provided at the contraction mixing structure 27 at the entrance of the secondary combustion chamber 29.

[0113] Combustion treatment process: pyrolysis temperature is controlled at 1250-1300°C, the air-fuel ratio of the pyrolysis section is 0.6, the temperature of the primary combustion chamber is controlled at 1100-1120°C, and the temperature of the secondary combustion chamber is controlled at 1050-1065°C.

[0114] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 125mg / Nm 3 The outlet oxygen concentration is about 3.5%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.66%.

[0115] Example 6: Waste gas and waste liquid incineration project of a chemical plant

[0116] Raw materials: Same as Example 5.

[0117] Combustion treatment device: Same as Example 5.

[0118] Feed: Same as Example 5.

[0119] Combustion treatment process: pyrolysis temperature is controlled at 1200-1250°C, the air-fuel ratio of the pyrolysis section is 0.65, the temperature of the primary combustion chamber is controlled at 1050-1065°C, and the temperature of the secondary combustion chamber is controlled at 950-1000°C.

[0120] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 110mg / Nm 3 The outlet oxygen concentration is about 3.0%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.58%.

[0121] Example 7: Waste gas and waste liquid incineration project of a chemical plant

[0122] Raw materials: Same as Example 5.

[0123] Combustion treatment device: Same as Example 5.

[0124] Feeding: solid waste 1 is fed into the rotary pyrolysis furnace through a feeder, high calorific value waste liquids 1, 2, 3, 4 are fed into the pyrolysis section through the waste liquid spray gun of the multi-media burner panel via the high calorific value waste liquid inlet 15, and high nitrogen waste gases 1, 2, 3 are fed into the pyrolysis section through the waste gas distributor via the nitrogen-containing waste gas inlet 13. The primary combustion chamber of the combustion section is provided with a combustion section primary air inlet 21, a recirculating flue gas interface 23, a waste gas 2 interface, and a waste liquid 5 interface, and the contraction mixing structure 27 at the entrance of the secondary combustion chamber 29 is provided with a combustion section secondary air inlet 28.

[0125] Combustion treatment process: The pyrolysis temperature is controlled at 1300-1350°C, the air-fuel ratio of the pyrolysis section is 0.60, the temperature of the primary combustion chamber is controlled at 1100-1120°C, and the temperature of the secondary combustion chamber is controlled at 1000-1050°C.

[0126] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 150mg / Nm 3 The outlet oxygen concentration is about 3.2%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.79%.

[0127] Example 8: Waste gas and waste liquid incineration project of a chemical plant

[0128] Raw materials: Same as Example 5.

[0129] Combustion treatment device: Same as Example 5.

[0130] Feed: Same as Example 7.

[0131] Combustion treatment process: The pyrolysis temperature is controlled at 1200-1250°C, the air-fuel ratio of the pyrolysis section is 0.60, the temperature of the primary combustion chamber is controlled at 1050-1100°C, and the temperature of the secondary combustion chamber is controlled at 950-1000°C.

[0132] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 100mg / Nm 3 The outlet oxygen concentration is about 2.7%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.53%.

[0133] Example 9: A high nitrogen content waste gas and waste liquid incineration project in a factory.

[0134] Raw materials: The combustion raw materials include 4 waste liquids and 2 waste gases, and the total nitrogen content of the raw materials is 2.35%wt (calculated as N, excluding N2 content).

[0135] Waste liquid 1: MMA device waste acid (containing 52.2%wt ammonium bisulfate, 7.4%wt MAA, 17.4%wt sulfuric acid, and the rest is water),

[0136] Waste liquid 2: Waste acid from acrylonitrile plant (containing 39.5%wt ammonium sulfate, 21%wt acrylic acid, 14.5%wt C6H8N2, and the rest is water),

[0137] Waste liquid 3: Alkylation unit waste acid (containing 91%wt sulfuric acid, 8.2%wt N-C5H1 acrylic acid, and the rest is water),

[0138] Waste liquid 4: MMA device wastewater (containing 0.4%wt sulfuric acid, 1%wt MMA, 4.4%wt acetone, and the rest is water).

[0139] Waste gas 1: MMA device waste gas (containing 26.7% v CO, 4.2% v MMA, 12.4% v acetone, 5.8% v methanol, 30.4% v C2H6O, 14.5% v N2, 3.5% v SO2, and the rest are inert gases, oxygen, and water)

[0140] Waste gas 2: H2S gas (containing 95%v H2S, 0.08%v C1+C2+C3, the rest is inert gas, oxygen, water)

[0141] Combustion treatment device: Since there is no solid waste in this embodiment, the pyrolysis section and the combustion section are optimized. The pyrolysis section adopts a fixed pyrolysis furnace, and the combustion section cancels the fluidized structure and only adopts segmented combustion. A primary combustion chamber and a secondary combustion chamber and a contraction mixing structure 27 are set between the two.

[0142] Feeding: High nitrogen waste liquids 1, 2, 3 are fed into the pyrolysis section through the waste liquid spray gun via the nitrogen-containing waste liquid inlet 14, high nitrogen waste gas 1 and waste gas 2 are fed into the pyrolysis section through the waste gas spray gun via the nitrogen-containing waste gas inlet 13, and a supplementary burner is provided in the pyrolysis section. The primary combustion chamber 20 of the combustion section is provided with a combustion section primary air inlet 21 and a waste liquid 4 interface, and the contraction mixing structure 27 at the entrance of the secondary combustion chamber 29 is provided with a combustion section secondary air inlet 28.

[0143] Combustion treatment process: The temperature of the pyrolysis section is controlled at 1250-1280°C, the air-fuel ratio of the pyrolysis section is 0.70, the temperature of the primary combustion chamber of the combustion section is controlled at 1150-1180°C, and the temperature of the secondary combustion chamber is controlled at 1065-1080°C.

[0144] Treatment effect: NOx concentration in the flue gas at the incinerator outlet: 180mg / Nm 3 The outlet oxygen concentration is about 2.1%, VOCs cannot be detected, and the NOx conversion rate of the entire raw nitrogen is about 0.76%.

[0145] Example 10: A high nitrogen content waste gas and waste liquid incineration project in a factory.

[0146] Raw materials: same as Example 9.

[0147] Combustion treatment device: Same as Example 9.

[0148] Feed: Same as Example 9.

[0149] Combustion treatment process: pyrolysis temperature is controlled at 1260-1300℃, air-fuel ratio in pyrolysis stage is 0.80, combustion chamber temperature is controlled at 1170-1200℃, and secondary combustion chamber temperature is controlled at 1065-1080℃.

[0150] Treatment effect: NOx concentration in the flue gas at the incinerator outlet: 260mg / Nm 3 The outlet oxygen concentration is about 2.3%, and VOCs cannot be detected. The NOx conversion rate of the entire raw nitrogen is about 1.10%.

[0151] Comparative Example 1: Waste gas and waste liquid incineration project of a chemical plant

[0152] Raw materials: Contains 2 types of waste liquids, 2 types of waste gases, and the total nitrogen content of the raw materials is 2.5%wt (calculated as N, excluding N2 content).

[0153] Waste liquid 1: DMC purified light components (containing 41.95%wt MF, 49.14%wt ML, 8.4%wt ME, 0.51%wt DMC)

[0154] Waste liquid 2: DMC purified heavy components (containing 60%wt DMC, 40%wt DMO)

[0155] Waste gas 1: MN recovery tower vent air (containing 0.6%v methyl nitrite, 2.9%v NO, 0.8%v N2O, 0.24%v ML, 0.76%v ME, 13.02%v CO, the rest is inert gas N2 and CO2)

[0156] Waste gas 2: DMC device waste gas (containing 31.2%v methyl nitrite, 1.6%v NO, 2.5%v N2O, 1.1%v CO, 1.3%v CH3Cl, 2.9%v DME, 4.4%v ML, the rest is N2, CO2 and water vapor)

[0157] Combustion treatment device: a two-stage combustion furnace consisting of a pre-combustion chamber and a burnout chamber.

[0158] Feed: Waste gases 1, 2 and waste liquids 1, 2 are sprayed into the pre-combustion chamber through the panel of the multi-media burner.

[0159] Combustion treatment process: Control the combustion temperature of the burnout chamber to 1100-1150℃.

[0160] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 11100mg / Nm 3The outlet oxygen concentration is about 6.0%, and the non-methane total hydrocarbons occasionally exceed 20 mg / Nm 3 The NOx conversion rate of the entire raw nitrogen is about 43.6%.

[0161] Comparative Example 2: Waste gas and waste liquid incineration project of a chemical plant

[0162] Raw materials: The processed raw materials include 1 waste liquid and 1 waste gas, and the total nitrogen content of the raw materials is 0.8%wt (calculated as N, excluding N2 content).

[0163] Waste gas 1: Absorption tower discharges air (containing 60mg / Nm 3 C3H3N, 900mg / Nm 3 NO2, 88.34%wt N2, 1.03%wtCO, the rest are inert gases, oxygen, water) high nitrogen waste gas

[0164] Waste liquid 1: Acrylonitrile waste liquid (containing 5.4%wt C3H5N, the rest is water)

[0165] Combustion treatment device: a two-stage combustion furnace consisting of a pre-combustion chamber and a burnout chamber.

[0166] Feed: Waste gas 1 and waste liquid 1 are sprayed into the pre-combustion chamber through the multi-media burner panel.

[0167] Combustion treatment process: Control the combustion temperature of the burnout chamber to 1100-1150℃.

[0168] Treatment effect: NOx concentration of flue gas at the incinerator outlet: 3950mg / Nm 3 The outlet oxygen concentration is about 6.1%, and the non-methane total hydrocarbons occasionally exceed 20 mg / Nm 3 , the NOx conversion rate of the entire raw nitrogen is about 50.5%.

[0169] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A multiphase combustion treatment device for nitrogen-containing raw materials, Features: It includes a pyrolysis section and a combustion section connected as one body; One end of the pyrolysis section is provided with a multi-medium burner and a plurality of nitrogen-containing raw material inlets; the multi-medium burner is provided with a plurality of inlets for introducing high calorific value waste gas and waste liquid and air for combustion of high calorific value waste gas and waste liquid; the nitrogen-containing raw material inlet includes any one or more of a solid waste inlet, a nitrogen-containing waste gas inlet, and a nitrogen-containing waste liquid inlet; the nitrogen-containing raw material in the pyrolysis section generates a large amount of CO, H 2 , hydrocarbon reducing gas, thereby inhibiting the conversion of ammonia nitrogen in the nitrogen-containing raw materials into nitrogen oxides. At the same time, the generated nitrogen oxides and the nitrogen oxides carried by the nitrogen-containing exhaust gas itself are reduced to nitrogen at high temperature; The combustion section includes a primary combustion chamber and a secondary combustion chamber which are internally connected, and the secondary combustion chamber is located on the upper side of the primary combustion chamber. The primary combustion chamber is interconnected with the other end of the pyrolysis section away from the multi-media burner. The residue after treatment by the pyrolysis section enters the combustion section. By adopting a multi-combustion chamber structure, the pyrolysis products can be subjected to sufficient deep reaction treatment in stages and sections.

2. The multiphase combustion treatment device for nitrogen-containing raw materials according to claim 1, Features: The pyrolysis section adopts a rotary pyrolysis furnace or a fixed pyrolysis furnace, and the multi-media burner is fixed at one end of the rotary pyrolysis furnace or the fixed pyrolysis furnace; and / or; The multi-media burner is provided with a high calorific value waste liquid inlet, a high calorific value waste gas inlet, and a pyrolysis section primary air inlet.

3. The multiphase combustion treatment device for nitrogen-containing raw materials according to claim 1, Features: A primary air inlet for the combustion section is arranged at the bottom of the primary combustion chamber.

4. The multiphase combustion treatment device for nitrogen-containing raw materials according to claim 3, Features: A fluidizing structure or a flow guiding structure is provided at the bottom of the primary combustion chamber above the primary air inlet of the combustion section, wherein the fluidizing structure is provided with a fluidized bed material; and the flow guiding structure adopts a flow guiding plate or a flow guiding grid.

5. The multiphase combustion treatment device for nitrogen-containing raw materials according to claim 3 or 4, Features: An external interface is provided on the outer wall of the primary combustion chamber, including any one or more combinations of a recycled flue gas interface, a low calorific value waste gas interface, a low calorific value waste liquid interface and a wastewater interface; wherein the flue gas of the combustion section escapes from the top and is connected to the recycled flue gas interface after heat recovery and purification.

6. The multiphase combustion treatment device for nitrogen-containing raw materials according to claim 4, Features: A contraction-type mixing structure is arranged at the inlet of the secondary combustion chamber, and the contraction-type mixing structure is located between the primary combustion chamber and the secondary combustion chamber; a combustion section secondary air interface is arranged on the throat contraction section of the contraction-type mixing structure.

7. The treatment process of the multiphase combustion treatment device for nitrogen-containing raw materials according to any one of claims 1 to 6, It is characterized in that The steps include: S1, solid waste materials and / or nitrogen-containing waste gas and / or nitrogen-containing waste liquid are respectively sent to the pyrolysis section through the corresponding inlets for pyrolysis treatment. At the same time, high calorific value waste gas and waste liquid and primary air of the pyrolysis section are sent to the pyrolysis section for combustion through the multi-media burner to provide heat for the high-temperature pyrolysis of nitrogen-containing raw materials in the pyrolysis section; the pyrolysis of nitrogen-containing raw materials in the pyrolysis section produces a large amount of CO, H 2 , hydrocarbon reducing gas, thereby inhibiting the conversion of ammonia nitrogen in the nitrogen-containing raw materials into nitrogen oxides. At the same time, the generated nitrogen oxides and the nitrogen oxides carried by the nitrogen-containing exhaust gas itself are reduced to nitrogen at high temperature; S2. The pyrolysis products of the pyrolysis section enter the multiple combustion chambers of the combustion section, and are burned and purified step by step. The purified flue gas escapes from the top of the combustion section.

8. The treatment process according to claim 7, Features: In step S2, the combustion section includes a primary combustion chamber, a contraction mixing structure, and a secondary combustion chamber arranged in sequence from bottom to top; The pyrolysis product first enters the primary combustion chamber, and primary air is introduced into the bottom of the primary combustion chamber through the primary air inlet of the combustion section. At the same time, the waste water and / or low calorific value waste gas and / or low calorific value waste liquid introduced from the outside are converted into gaseous substances in the primary combustion chamber by the high temperature of the pyrolysis product, and then mixed with the pyrolysis product and the primary air, so that the waste water and / or low calorific value waste gas and / or low calorific value waste liquid and the pyrolysis product are fully burned in the primary combustion chamber, and the smoke after combustion escapes to the contraction mixing structure; A secondary air interface for the combustion section is provided on the throat contraction section of the contraction mixing structure. The secondary air and the flue gas from the primary combustion chamber are strongly mixed at the contraction mixing structure and then flow upward into the secondary combustion chamber, so that the unreacted combustibles in the pyrolysis section and the primary combustion chamber are completely burned in the secondary combustion chamber, and then the flue gas escapes from the top of the secondary combustion chamber.

9. The process according to claim 8, Features: In step S1, the primary air volume in the pyrolysis section is controlled so that the air-fuel ratio in the pyrolysis section is maintained between 0.6 and 0.9 and the temperature is maintained between 1200° C. and 1350° C.; and / or; In step S2, the temperature in the primary combustion chamber is maintained at 950° C. to 1200° C. by controlling the wastewater and / or low calorific value waste liquid and / or low calorific value waste gas and the primary air volume; and / or; In step S2, the temperature in the secondary combustion chamber is maintained at 850°C to 1100°C and the oxygen content is maintained at 1% to 5% by controlling the amount of secondary air.

Images