JP7715797B2 - Reactor assembly, sulfur-containing waste treatment system, method for burning sulfur-containing waste, and method for producing sulfuric acid by regenerating sulfur-containing waste - Google Patents

Description

Detailed Description of the Invention

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Chinese patent applications 202011148953.4 and 202011150297.1 filed on October 23, 2020, and Chinese patent applications 202110739636.8, 202110736744.X, 202110736751.X, 202110736752.4, 202121481507.5, and 202110736743.5 filed on June 30, 2021, the contents of which are incorporated herein by reference.

[Technical Field]
The present invention relates to the treatment of sulfur-containing waste, and more particularly to a reactor assembly, a sulfur-containing waste treatment system, a method for burning sulfur-containing waste, and a method for producing sulfuric acid by regenerating sulfur-containing waste.

[Background technology]
The petrochemical and organic synthesis industries widely use concentrated sulfuric acid as a catalyst, generating large amounts of waste sulfuric acid during the process. Some organic synthesis processes, such as the synthesis of methyl methacrylate (MMA) and acrylonitrile (AN), produce approximately 30-45 wt% of waste ammonium sulfate in addition to waste sulfuric acid. Because these sulfur-containing wastes cause serious environmental pollution, it is necessary to purify and treat industrial waste acids and sulfur-containing waste liquids to maximize their recycling.

The main methods for treating sulfur-containing waste include high-temperature concentration, solvent extraction, alkaline neutralization and chemical oxidation, and high-temperature combustion decomposition. Currently, the high-temperature combustion method is thorough and environmentally friendly, but suffers from low combustion efficiency, high operating costs, and complex operations.

Summary of the Invention
[Problem to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a reactor assembly and a sulfur-containing waste treatment system that can solve the problems existing in the prior art and reduce the generation of nitrogen oxides by burning sulfur-containing waste.

[Means for solving the problem]
In order to achieve the above object, the present invention provides a reactor assembly, which includes a furnace for receiving sulfur-containing waste and carrying out a combustion reaction therein, and a fuel gas inlet and a process gas outlet, each of which communicates with the furnace, the fuel gas inlet and the process gas outlet being arranged at both ends of the furnace along the axial direction of the furnace with a space therebetween, the fuel gas inlet including a cylindrical reactor body configured to be able to supply fuel flowing along the axial direction of the furnace to the furnace, and a combustion supporting air supply mechanism configured to be able to supply combustion supporting air flowing along the circumferential direction of the inner wall of the furnace to the furnace.

Preferably, the auxiliary combustion air supply mechanism includes a group of multiple auxiliary combustion air supply ports spaced apart along the axial direction of the furnace.

Preferably, the plurality of combustion supporting air supply port groups include a first air supply port group and a second air supply port group, the first air supply port group being provided close to the fuel gas inlet, and the second air supply port group being provided close to the process gas outlet,
The reactor assembly includes a control device for controlling the auxiliary combustion air supply mechanism, which is configured to control air to enter through the first air supply port group and to control the amount of oxygen at the position of the first air supply port group to be a first oxygen amount, and to control the air to enter through the second air supply port group and to control the amount of oxygen at the position of the second air supply port group to be a second oxygen amount which is the theoretical oxygen amount for normal combustion of sulfur-containing waste and is greater than the first oxygen amount, and further to control the fuel and the sulfur-containing waste to be combusted to undergo at least two combustions, including a first combustion corresponding to the first oxygen amount and a second combustion corresponding to the second oxygen amount, and ultimately to obtain a sulfur dioxide-containing gas.

Preferably, in the first combustion, the oxygen coefficient is X1 and the temperature is 1100-1250°C; in the final combustion, the oxygen coefficient is X3 and the temperature is 1000-1100°C; and in any subsequent combustions, the oxygen coefficients are each independently X2 and the temperatures are each independently 1100-1200°C, and 0.5≦X1≦0.85, 0.7≦X1+X2≦1, and 1≦X1+X2+X3≦1.15, where the oxygen coefficients are the ratio of the oxygen-containing auxiliary gas converted to the oxygen molar content to the oxygen molar content required for complete combustion of the fuel.

According to the above technical proposal, fuel gas enters the furnace through the fuel gas inlet and flows along the axial direction of the furnace. Furthermore, the auxiliary combustion air supplied to the furnace by the auxiliary combustion air supply mechanism flows circumferentially around the inner wall of the furnace. This allows the mixed gas of fuel gas and auxiliary combustion air to flow spirally toward the process gas outlet. As a result, during the spiral flow, the mixed gas has a longer residence time in the furnace and can fully combustibly react with the sulfur-containing waste mixture, thereby improving the combustion efficiency of the reactor assembly. Furthermore, because the mixed gas can reside in the furnace for a longer period of time, the distance between the fuel gas inlet and the process gas outlet can be shortened, enabling the reactor assembly of the present invention to be made more compact.

The present invention also provides a method for producing a semiconductor device comprising:
The present invention provides a sulfur-containing waste treatment system, which includes the above-mentioned reactor assembly for burning sulfur-containing waste to obtain a first gas containing sulfur dioxide, a thermal energy recovery unit for recovering thermal energy from the first gas to obtain a second gas, a purification and cooling unit for purifying and cooling the second gas to obtain a third gas, a drying unit for drying the third gas to obtain a fourth gas, and an oxidation and absorption unit for oxidizing and absorbing the fourth gas to obtain sulfuric acid and an exhaust gas.

According to the above technical proposal, by adopting the sulfur-containing waste treatment system and reactor assembly of the present invention, oxygen-deficient combustion first occurs in the reactor, reducing the generation of nitrogen oxides. Then, oxygen-enriched combustion occurs at the end, achieving the desired combustion, but because the temperature at the end is low, the generation of nitrogen oxides also decreases. The reduction in nitrogen oxides improves the sulfur dioxide content in the process gas, and the desired combustion occurs without affecting the normal process.

The present invention provides a method for burning sulfur-containing waste based on the above-mentioned reactor assembly, and a method for producing sulfuric acid by regenerating sulfur-containing waste based on the above-mentioned sulfur-containing waste treatment system.

[Effects of the Invention]
The positive effects of the present invention are as follows: The present invention provides an optimized and improved mixed treatment process and device for waste sulfuric acid and sulfur-containing solid waste, sulfur-containing waste liquid, and sulfur-containing waste gas, which shortens the process flow as much as possible, reduces the equipment, simplifies the operation, and increases the utilization rate of thermal energy. The sulfur element in the raw material is regenerated to 93-100% sulfuric acid and oleum.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a reactor assembly in accordance with one embodiment of the present invention.

[Figure 2] A side view of the furnace of the reactor assembly of the present invention.

[Figure 3] Front view of the furnace of the reactor assembly of the present invention.

[Figure 4] Schematic diagram of the heating device of the reactor assembly of the present invention.

[Figure 5] A flowchart of a reactor combustion control method for a sulfur-containing waste treatment system according to one embodiment of the present invention.

[Figure 6] A flowchart of a reactor combustion control method for a sulfur-containing waste treatment system according to one embodiment of the present invention.

[Figure 7] Schematic diagram of the process flow of a sulfur-containing waste treatment system according to an embodiment of the present invention.

[Figure 8] Flowchart of the sulfuric acid production method of the present invention by regenerating sulfur-containing waste.

[Figure 9] Schematic diagram of the dust collection unit and thermal energy recovery unit.

[Figure 10] Schematic diagram of a quenching and humidifying tower.

[Figure 11] Schematic diagram of a cooling absorption tower.

[Figure 12] Schematic diagram of the oxidation absorption unit.

[Figure 13] Schematic diagram of a converter.

[Mode for Carrying Out the Invention]
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Note that the specific embodiments described here are merely for the purpose of explaining and interpreting the present invention, and are not intended to limit the present invention.

As shown in Figures 1 to 3, the reactor assembly of the present invention includes a reactor body 100 having a cylindrical furnace 111 for a combustion reaction of sulfur-containing waste. The reactor body 100 is further provided with a fuel gas inlet 112 and a process gas outlet 113 communicating with the furnace 111, the fuel gas inlet 112 and the process gas outlet 113 being provided at both ends of the furnace 111 along the axial direction of the furnace 111 with a space between them, and the fuel gas inlet 112 is configured to be able to supply fuel gas flowing along the axial direction of the furnace 111 to the furnace 111. The reactor assembly 100 also includes a combustion support air supply mechanism configured to be able to supply combustion support air flowing circumferentially around the inner wall of the furnace 111.

In the present invention, fuel gas enters the furnace 111 through the fuel gas inlet 112 and flows along the axial direction of the furnace 111. Furthermore, the supporting air supplied to the furnace 111 by the supporting air supply mechanism can flow along the circumferential direction of the inner wall of the furnace 111. This allows the mixed gas of fuel gas and supporting air to flow spirally (see FIG. 2) to the process gas outlet 113. As a result, during the spiral flow, the mixed gas has a longer residence time in the furnace 111, allowing for a sufficient combustion reaction with the sulfur-containing waste mixture. This improves the combustion efficiency of the reactor assembly. Furthermore, because the mixed gas can reside in the furnace 111 for a longer period of time, the distance between the fuel gas inlet 112 and the process gas outlet 113 is shorter, enabling the reactor assembly of the present invention to be made more compact.

In addition, the auxiliary combustion air supply mechanism may be designed in various forms to drive the auxiliary combustion air to flow circumferentially around the inner wall of the furnace 111 in the furnace 111. For example, the auxiliary combustion air supply mechanism may include an auxiliary combustion air nozzle and a guide fan, where the auxiliary combustion air nozzle is used to supply combustion air to the furnace 111 and the guide fan is installed in the furnace 111 to change the flow direction of the auxiliary combustion air, allowing the auxiliary combustion air to flow circumferentially around the inner wall of the furnace 111 under the guidance of the guide fan after leaving the auxiliary combustion air nozzle. To further reduce costs and simplify the structure of the reactor assembly, in one embodiment of the present invention, the auxiliary combustion air supply mechanism includes a group of auxiliary combustion air inlets, each of which includes a first auxiliary combustion air inlet 114 and a second auxiliary combustion air inlet 115, each of which is connected to the furnace 111. The first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 are each configured to supply auxiliary combustion air to the furnace 111 along a tangential direction of the furnace 111, and the flow direction of the auxiliary combustion air supplied by the first auxiliary combustion air inlet 114 is the same as that of the second auxiliary combustion air inlet 115. Since both the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 are opened along a tangential direction of the inner wall of the furnace 111, all of the auxiliary combustion air ejected from the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 can flow in the circumferential direction of the inner wall of the furnace 111, which eliminates the need for additional components, simplifies the structure, and facilitates maintenance.

Of course, the auxiliary combustion air inlet group may include a third auxiliary combustion air inlet, a fourth auxiliary combustion air inlet, etc. in addition to the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115, and all of these auxiliary combustion air inlets are located on the same radial plane of the furnace 111 and are arranged to open in the same direction (i.e., both clockwise or counterclockwise), thereby enabling the mixed gas to flow spirally within the furnace 111.

It should be noted that in one embodiment of the present invention, as shown in Figures 2 and 3, the opening directions of the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 are both perpendicular to the axial direction of the furnace 111, i.e., the flow direction of the fuel gas is perpendicular to the plane defined by the flow direction of the auxiliary combustion air. In another embodiment of the present invention, the opening directions of the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 are both inclined toward the fuel gas inlet 112. With this configuration, the flow direction of the auxiliary combustion air entering the furnace 111 is opposite to the flow direction of the fuel gas, which has the advantages of more thorough mixing of the auxiliary combustion air and the fuel gas, reducing the flow velocity of the mixed gas, increasing the flow time of the mixed gas in the furnace 111, and making the reactor assembly more compact. Of course, the opening directions of the first auxiliary combustion air inlet 114 and the second auxiliary combustion air inlet 115 may be slightly inclined toward the fuel gas inlet 112, for example, by 20 to 40 degrees toward the fuel gas inlet 112.

To more fully supply supporting air, in one embodiment of the present invention, as shown in FIG. 2, the supporting air supply mechanism includes multiple supporting air supply inlet groups, which are spaced apart along the axial direction of the furnace 111. In the preferred embodiment shown, the reactor body 100 is provided with two of the aforementioned first and second supporting air inlets 114 and 115, respectively. Here, the supporting air inlets 114a and 115a closer to the fuel gas inlet 112 constitute the first air supply inlet group, and the supporting air inlets 114b and 115b closer to the process gas outlet 113 constitute the second air supply inlet group. Therefore, the combustion of sulfur-containing waste can be controlled by the amount of supporting air introduced into the furnace 111 from the first and second air supply inlet groups.

Specifically, the flowchart of the reactor combustion control method for a sulfur-containing waste treatment system shown in Figure 5 includes steps S11 to S13.

Step S11: Detect the amount of oxygen at the positions of the first air supply port group and the second air supply port group.

For example, oxygen sensors for detecting the amount of oxygen may be provided in the first air supply port group and the second air supply port group.

Step S12: Air enters through the first group of air supply ports, and the amount of oxygen at the position of the first group of air supply ports is controlled to be the first amount of oxygen.

For example, the amount of oxygen at the position of the first air supply port group may be referenced, and air may be added/reduced to the first air supply port group, so that the amount of oxygen at the position of the first air supply port group becomes a first oxygen amount, for example, 60% of the theoretical oxygen amount in normal combustion of the sulfur-containing waste, thereby causing oxygen-deficient combustion of the sulfur _- containing waste, and reducing the generation of nitrogen oxides during the reaction of nitrogen-containing substances contained _therein , such as ( _NH4 ) _2SO4 and/or _NH4HSO4 .

Step S13: The air enters through the second group of air supply ports, and the amount of oxygen at the position of the second group of air supply ports is controlled to be a second amount of oxygen, which is the theoretical amount of oxygen resulting from normal combustion of sulfur-containing waste and is greater than the first amount of oxygen.

For example, to achieve normal combustion, air is supplied to the second group of air supply ports at the end of the reactor, and the amount of oxygen at the position of the second group of air supply ports is set to a second amount of oxygen, which is, for example, the theoretical amount of oxygen required for normal combustion of the sulfur-containing waste, so that the sulfur-containing waste will burn normally. Since the amount of nitrogen oxides produced is related to temperature, i.e., increases as the temperature rises, if the temperature at the end of the reactor, away from the flame core, is low, the amount of nitrogen oxides produced will decrease even though the amount of oxygen is sufficient.

By adopting the above method, nitrogen oxides are reduced, the sulfur dioxide content in the process gas in the reactor is improved, and the desired combustion is achieved without affecting the normal process.

Figure 6 is a flowchart of a reactor combustion control method for a sulfur-containing waste treatment system according to another embodiment of the present invention. In this embodiment, the reactor body further includes a third air supply port provided in the center of the reactor body, and the method includes steps S21 to S24.

Step S21: Detect the amount of oxygen at the positions of the first air supply port group and the second air supply port group.

Step S22: Air enters through the first group of air supply ports, and the amount of oxygen at the position of the first group of air supply ports is controlled to be the first amount of oxygen.

For example, the implementation of steps S21-22 is similar to the implementation of steps S11-12 above and will not be described in detail here.

Step S23: The air enters through the third group of air supply ports, and the amount of oxygen at the position of the third group of air supply ports is controlled to be a third amount of oxygen. The third amount of oxygen may be, for example, 95% of the second amount of oxygen. This also allows the sulfur-containing waste to undergo oxygen-deficient combustion, and reduces the generation of nitrogen oxides during reaction _of nitrogen-containing substances contained therein, such as ( _{NH4 ) 2SO4} and/or _NH4HSO4 .

Step S24: The air enters through the second group of air supply ports, and the amount of oxygen at the position of the second group of air supply ports is controlled to be a second amount of oxygen, which is the theoretical amount of oxygen resulting from normal combustion of sulfur-containing waste, and is greater than the first amount of oxygen and greater than the third amount of oxygen.

For example, similarly, to ensure normal combustion, air is replenished to the second group of air supply ports at the end of the reactor, and the amount of oxygen at the location of the second group of air supply ports is set to a second amount of oxygen, thereby ensuring normal combustion of the sulfur-containing waste.

Note that while the above describes only examples having two air supply port groups and three air supply port groups, the reactor may have more air supply ports, for example, multiple third air supply port groups, and these air supply ports may supply air simultaneously, as long as the amount of oxygen at the terminal air supply port is the theoretical amount of oxygen resulting from normal combustion of the sulfur-containing waste, and the amounts of oxygen at the remaining air supply ports are all less than the theoretical amount of oxygen resulting from normal combustion of the sulfur-containing waste; this will not be described in detail here.

In the above process, the fuel and the sulfur-containing waste to be burned are controlled to undergo at least two combustions, including a first combustion corresponding to the first amount of oxygen and a second combustion corresponding to the second amount of oxygen, ultimately producing a sulfur dioxide-containing gas.

Here, in the first combustion, the oxygen coefficient is X1 and the temperature is 1100-1250°C; in the final combustion, the oxygen coefficient is X3 and the temperature is 1000-1100°C; in any additional combustions present, the oxygen coefficient is X2 and the temperatures are each independently 1100-1200°C; and 0.5≦X1≦0.85, 0.7≦X1+X2≦1, 1≦X1+X2+X3≦1.15. The oxygen coefficients are the ratio of the molar amount of the oxygen-containing combustion supporting gas converted into oxygen to the molar amount of oxygen required for complete combustion of the fuel.

In the present invention, the oxygen coefficient is the ratio of the molar amount of the oxygen-containing combustion supporting gas converted to the oxygen contained in each combustion to the molar amount of oxygen required for complete combustion of the fuel, where the fuel is the initial total fuel, not the surplus fuel from the previous combustion.

According to the present invention, the amount of oxygen-containing combustion supporting gas used is controlled for each combustion, the oxygen coefficient for each combustion is adjusted, and in combination with other process conditions for each combustion, such as temperature, the sulfur-containing waste is combusted sufficiently to obtain a process gas with a high sulfur dioxide content.

Furthermore, particularly in the case of reactant materials containing nitrogen element, the method according to the present invention can significantly reduce the content of nitrogen oxides (NO _x ) in the resulting process gas without the need for additional denitrification treatment, which is environmentally friendly, economical and efficient.

Preferably, in the first combustion, the oxygen coefficient is X1 and the temperature is 1150-1250°C, in the final combustion, the oxygen coefficient is X3 and the temperature is 1050-1100°C, and in the optional excess combustions, the oxygen coefficients are each independently X2 and the temperatures are each independently 1100-1200°C, and 0.7≦X1≦0.85, 0.8≦X1+X2≦1, and 1≦X1+X2+X3≦1.15. Therefore, the inventors of the present invention have found that, particularly when the oxygen coefficient and temperature in the reaction for each combustion are controlled within the above-mentioned preferred ranges, by combining these, the combustion of the sulfur-containing waste can be more complete, the sulfur dioxide content in the resulting sulfur dioxide-containing process gas can be higher, and the _NOx content in the resulting process gas can be lower, especially in the case of reaction materials containing nitrogen element.

According to the present invention, "at least two combustions" may refer to multiple combustions, such as two or more (e.g., three, four, or five). In other words, "optionally present" may refer to the presence or absence of excess combustion.

Preferably, the number of combustions is 2 to 3.

It should be noted that according to the present invention, if there are two combustions, there is only the first combustion and the last combustion, and there is no extra combustion.

According to one preferred specific embodiment of the present invention, the number of combustions is two, and the method comprises:
The method includes a step of sequentially performing a first combustion and a second combustion on a fuel and a sulfur-containing waste to be burned in the presence of an oxygen-containing combustion supporting gas to obtain a sulfur dioxide-containing gas.

Preferably, the conditions for the first combustion include an oxygen coefficient X1 and a temperature of 1150 to 1250°C, and the conditions for the second combustion include an oxygen coefficient X3, a temperature of 1050 to 1100°C, 0.7≦X1≦0.85, and 1≦X1+X3≦1.15.

According to another preferred specific embodiment of the present invention, the number of combustions is three, and the method comprises the steps of:
The method includes a step of sequentially performing a first combustion, a second combustion, and a third combustion on a fuel and a sulfur-containing waste to be burned in the presence of an oxygen-containing combustion supporting gas to obtain a sulfur dioxide-containing gas.

Preferably, the conditions for the first combustion include an oxygen coefficient X1 and a temperature of 1150 to 1250°C, the conditions for the second combustion include an oxygen coefficient X2 and a temperature of 1100 to 1200°C, and the conditions for the third combustion include an oxygen coefficient X3, a temperature of 1050 to 1100°C, and 0.7≦X1≦0.85, 0.8≦X1+X2≦1, and 1≦X1+X2+X3≦1.15.

Preferably, the oxygen-containing combustion supporting gas is at least one selected from air (oxygen content 21 mol%), oxygen-enriched air (oxygen content 21-40 mol%), pure oxygen, and liquid oxygen. The inventors of the present invention have discovered that using oxygen-enriched air with a high oxygen content or pure oxygen as the combustion supporting gas significantly reduces fuel consumption and enables a larger amount of sulfur-containing waste to be processed in a device of the same scale, thereby reducing investment in the device and lowering energy consumption and operating costs.

Preferably, the sulfur-containing waste is at least one selected from waste sulfuric acid, sulfur-containing waste liquid, and sulfur-containing waste gas.

The present invention does not particularly limit the origin or type of the sulfur-containing waste. The sulfur-containing waste liquid may be, for example, liquid sulfur, sulfur-containing waste liquid containing ammonium sulfate, sulfur-containing waste liquid containing ammonium bisulfate, sulfur-containing waste liquid containing iron sulfate, sulfur-containing waste liquid containing methyl sulfate, or sulfur-containing waste liquid containing gypsum. The sulfur-containing waste gas may be, for example, hydrogen sulfide, sulfur dioxide, or other waste gas containing sulfur components. Preferably, the mass concentration of sulfuric acid in the waste sulfuric acid is 50 to 99%. Preferably, the water content of the sulfur-containing waste is less than 15 wt%.

According to one preferred specific embodiment of the present invention, the reactor assembly further includes a liquid spray gun 116 configured to sufficiently atomize the sulfur-containing waste (e.g., sulfur-containing waste liquid). The sulfur-containing waste is atomized by high-pressure atomizing air in the liquid spray gun and then sprayed into the furnace, where it is combusted together with the oxygen-containing combustion supporting gas and the fuel, thereby more fully combusting the sulfur-containing waste and improving the sulfur dioxide content in the process gas. Preferably, the pressure of the liquid spray gun is 0.4 to 0.8 MPa, more preferably 0.5 to 0.7 MPa.

According to one preferred specific embodiment of the present invention, the sulfur-containing waste contains sulfur-containing solid waste (e.g., sulfur-containing mineral sand), and the method of the present invention includes the steps of: performing one combustion of the sulfur-containing solid waste (combustion conditions: temperature 800-1050°C) to obtain sulfur dioxide-containing gas II; performing at least two combustions of the sulfur-containing waste liquid and/or sulfur-containing waste gas to obtain sulfur dioxide-containing gas I; and combining the sulfur dioxide-containing gas II and the sulfur dioxide-containing gas I to obtain the sulfur dioxide-containing gas of the present invention.

According to the present invention, the fuel is capable of burning a combustible material with a high calorific value in the presence of an oxygen-containing combustion supporting gas to provide heat for the combustion of the sulfur-containing waste. Preferably, the calorific value of the fuel is 500 kcal/ ^Nm3 or more, for example, the calorific value of natural gas is 9700 kcal/ ^Nm3 .

Preferably, the fuel is at least one selected from natural gas, sulfur, liquefied hydrocarbons, hydrogen sulfide acid gas, and heavy oil organics.

Preferably, the liquefied hydrocarbon is at least one selected from liquefied ethylene, liquefied ethane, liquefied propylene, liquefied propane, liquefied butene, and liquefied butane.

Preferably, the heavy oil organic matter is at least one selected from gasoline, kerosene, and diesel.

According to the present invention, the amount of fuel used may be rationally selected and adjusted depending on the amount of sulfur-containing waste used.

It should be noted that, according to the present invention, the sulfur-containing waste and the fuel may be the same substance (e.g., hydrogen sulfide). As will be understood by those skilled in the art, if the sulfur-containing waste is hydrogen sulfide acid gas, the hydrogen sulfide acid gas itself can function as fuel, and there is no need to provide any additional fuel. This is also within the scope of the present invention, and those skilled in the art should not understand this as a limitation of the invention.

Preferably, according to the method for burning sulfur-containing waste of the present invention, the sulfur dioxide-containing gas obtained has a sulfur dioxide content of 3 to 12 mol%, a _NOx content of 100 mg/ ^m3 or less, and an oxygen content of 0.5 to 5 mol%.

In the present invention, by controlling the reaction conditions for each combustion, particularly the temperature and oxygen coefficient, the first combustion reaction of the fuel and the sulfur-containing waste to be burned is carried out under high temperature and oxygen-deficient conditions, so that the sulfur-containing waste burns to produce sulfur dioxide, and the nitrogen-containing material produces nitrogen gas under oxygen-deficient conditions. Subsequent combustions are carried out under low temperature and oxygen-rich conditions, ensuring sufficient combustion of the fuel and sulfur-containing waste, and the nitrogen gas produced by the previous combustion is too cold to further react to produce nitrogen oxides. Therefore, by combining multiple combustion reactions, a process gas with a high sulfur dioxide content and a low _NOx content is obtained, and the resulting sulfur dioxide-containing gas does not contain any combustible components.

According to the present invention, preferably, at least one of the oxygen-containing combustion supporting gas, the fuel, and the sulfur-containing waste contains a nitrogen element. The sulfur-containing waste is, for example, a nitrogen-sulfur-containing substance such as ammonium bisulfate or ammonium sulfate, the fuel is, for example, a combustible material containing nitrogen gas, and the oxygen-containing combustion supporting gas is, for example, air.

According to one preferred specific embodiment of the present invention, the method of the present invention further comprises the steps of first removing water from the sulfur-containing waste and then combusting the waste with fuel at least twice in the presence of an oxygen-containing combustion supporting gas to obtain a sulfur dioxide-containing gas.

In the present invention, there are no particular limitations on the specific procedures for the water removal treatment, as long as at least a portion of the water in the sulfur-containing waste is removed, and this can be done, for example, by evaporation and concentration.

In the method according to the present invention, the combustion conditions of the sulfur-containing waste are particularly controlled and multiple combustion reactions are coordinated to more thoroughly combust the sulfur-containing waste, resulting in a process gas with a high sulfur dioxide content, and the resulting sulfur dioxide-containing gas does not contain any combustible components.

In particular, in the case of nitrogen-containing reaction materials, the method of the present invention allows for more complete combustion of the sulfur-containing waste, particularly by controlling the conditions for each combustion, resulting in a process gas with a high sulfur dioxide content and a low _NOx content, and the nitrogen element in the nitrogen-containing reaction material is emitted in the form of nitrogen gas in addition to a very small amount _of NOx. By using the method of the present invention, the content of nitrogen oxides ( _NOx ) in the resulting process gas can be significantly reduced without the need for additional denitrification treatment.

Based on the above, the present invention also provides:
(1) burning sulfur-containing waste to obtain a sulfur dioxide-containing gas;
(2) oxidizing the sulfur dioxide-containing gas to obtain a sulfur trioxide-containing gas;
and (3) absorbing the sulfur trioxide-containing gas to obtain sulfuric acid.

The present invention will be explained in detail below using examples.

Unless otherwise noted, all materials used in the following examples are commercially available.

Unless otherwise specified, all of the following examples are performed using the reactor assembly described above. Two sets of combustion supporting gas inlets are distributed along the axial direction of the reactor (in the axial direction of the reactor, the straight cylindrical stage of the furnace has an axial length of L and an aspect ratio of 4 to 10 (e.g., an aspect ratio of 5), and two combustion supporting gas inlets are provided at a position 0.25 L away from the fuel inlet side of the furnace and a position 0.5 L away from the gas outlet side of the furnace). In order to provide the oxygen-containing combustion supporting gas required for each combustion, the oxygen-containing combustion supporting gas inlets are configured to be able to supply oxygen-containing combustion supporting gas that flows tangentially to the inner wall of the furnace.

Example 1A
The specific compositions of the fuel and sulfur-containing waste from the chemical fiber industry used in this example are shown in Table 1, and the oxygen-containing combustion supporting gas is air with an oxygen content of 21 mol %.

The reactor was heated to 1200°C, and room temperature air was pressurized with an air blower and heated to 630°C in an electric heating furnace and introduced into the reactor through the combustion support gas inlet. The sulfur-containing waste was sprayed into the reactor furnace through the sulfur-containing waste inlet with high-pressure atomized air at 0.6 MPa using a liquid spray gun. Fuel was introduced into the reactor furnace through the fuel inlet.

The specific process is as follows:

38.11 t of sulfur-containing waste (68.22 wt% waste sulfuric acid + 31.78 wt% sulfur-containing waste liquid) and 3,990 kg of fuel were introduced into the reactor through the sulfur-containing waste inlet and fuel inlet, respectively. In the axial direction of the furnace, a first combustion was carried out with oxygen-containing combustion supporting gas introduced through the first oxygen-containing combustion supporting gas inlet, and a second combustion was carried out with oxygen-containing combustion supporting gas introduced through the second oxygen-containing combustion supporting gas inlet. The conditions for the first combustion included an oxygen coefficient X1 of 0.7 and a temperature of 1,200°C. The conditions for the second combustion included an oxygen coefficient X3 (X1 + X3 = 1.05) and a temperature of 1,100°C. A sulfur dioxide-containing gas was obtained.

In the sulfur dioxide-containing gas from the furnace, the sulfur dioxide content was 3.8 mol%, the oxygen content was 2 mol%, the _NOx content was 100 mg/Nm3 or ^less , and the sulfur dioxide conversion rate was 99 mol%.

Example 1B
The procedure was similar to that of Example 1A, except that the oxygen-containing combustion supporting gas used was oxygen-enriched air with an oxygen content of 40 mol %.

In the sulfur dioxide-containing gas from the furnace, the oxygen content was 2 mol%, the sulfur dioxide content was 6 mol%, the _NOx content was 80 mg/Nm3 or ^less , and the sulfur dioxide conversion rate was 99 mol%.

Example 2
The specific compositions of the chlorine-containing waste sulfuric acid, hydrogen sulfide acid gas and fuel used in this example are shown in Table 2, and the oxygen-containing combustion supporting gas was air with an oxygen content of 21 mol %.

The reactor was heated to 1100°C, and room temperature air was introduced into the reactor through the combustion support gas inlet using an air blower. The sulfur-containing waste was sprayed into the reactor furnace through the sulfur-containing waste inlet using high-pressure atomized air at 0.7 MPa using a liquid spray gun, and fuel was introduced into the reactor furnace through the fuel inlet.

In this example, the sulfur-containing waste was 7 tons (71.43 wt% chlorine-containing waste sulfuric acid + 28.57 wt% hydrogen sulfide acid gas). Here, the chlorine-containing waste sulfuric acid from the polytetrahydrofuran production plant had a moisture content of 48 wt% and a low impurity content, and was evaporated and concentrated to 85 wt% before entering reactor 9. The hydrogen sulfide acid gas was a sulfur-containing waste gas, but it only supplied 70 mol% of the heat for the reactor system, with the remaining 30 mol% being supplemented by natural gas as an auxiliary fuel.

The specific reaction process is as follows:

Waste sulfuric acid was introduced into the reactor furnace through the sulfur-containing waste inlet, and hydrogen sulfide acid gas and natural gas were introduced into the reactor furnace through the fuel inlet. In the axial direction of the furnace, a first combustion was carried out with an oxygen-containing combustion supporting gas introduced through the first oxygen-containing combustion supporting gas inlet, and then a second combustion was carried out with an oxygen-containing combustion supporting gas introduced through the second oxygen-containing combustion supporting gas inlet. The conditions for the first combustion included an oxygen coefficient X1 of 0.75 and a temperature of 1150°C, and the conditions for the second combustion included an oxygen coefficient X3 (X1 + X3 = 1.05) and a temperature of 1050°C. A sulfur dioxide-containing gas was obtained.

In the sulfur dioxide-containing gas from the furnace, the oxygen content was 3 mol%, the sulfur dioxide content was 8.5 mol%, the _NOx content was 100 mg/Nm3 or ^less , and the sulfur dioxide conversion rate was 99 mol%.

Example 3
The specific compositions of the sulfur-containing waste and fuel used in this example are shown in Table 3, and the oxygen-containing combustion supporting gas is air with an oxygen content of 21 mol %.

The reactor was heated to 1250°C, and room temperature air was pressurized with an air blower and heated to 450°C in an electric heating furnace before being introduced into the reactor. The sulfur-containing waste was sprayed into the reactor furnace from the sulfur-containing waste inlet using a liquid spray gun with high-pressure atomized air at 0.5 MPa. Fuel was introduced into the reactor furnace from the fuel inlet.

The specific reaction process is as follows:

7.5 t of sulfur-containing waste (80 wt% waste sulfuric acid + 20 wt% sulfur-containing mineral sand) and 120 kg of fuel were introduced into the reactor through the sulfur-containing waste inlet and fuel inlet, respectively. A first combustion was performed in the axial direction of the furnace with oxygen-containing combustion supporting gas introduced through the first oxygen-containing combustion supporting gas inlet, followed by a second combustion with oxygen-containing combustion supporting gas introduced through the second oxygen-containing combustion supporting gas inlet. The first combustion conditions included an oxygen coefficient X1 of 0.85 and a temperature of 1200°C. The second combustion conditions included an oxygen coefficient X3 (X1 + X3 = 1.05) and a temperature of 1050°C. Sulfur dioxide-containing gas I was obtained. Sulfur-containing mineral sand was combusted in a separate reactor (temperature 800°C) to produce sulfur dioxide-containing process gas II.

In the sulfur dioxide-containing mixed gas from the two reactors, the oxygen content was 5 mol%, the sulfur dioxide content was 6 mol%, the _NOx content was 100 mg/Nm3 or less, and the sulfur dioxide conversion rate was ⁹⁹ mol%.

Comparative Example 1
A method similar to that of Example 1 was employed, except that the number of combustions was one.

Specifically, 38.11 t of sulfur-containing waste (68.22 wt% waste sulfuric acid + 31.78 wt% sulfur-containing waste liquid) and 4,588 kg of fuel were introduced into the reactor furnace through the material inlet and combusted in the axial direction of the furnace with oxygen-containing combustion supporting gas introduced through the first oxygen-containing combustion supporting gas inlet. Combustion conditions included an oxygen coefficient of 1.04 and a temperature of 1,150°C. A sulfur dioxide-containing gas was obtained.

The sulfur dioxide-containing gas temperature from the furnace was 950-1000°C, the oxygen content was 1.8 mol%, the sulfur dioxide content was 3.2 mol%, the _NOx content was about 500 mg/ ^Nm3 , and the sulfur dioxide conversion rate was 98.8 mol%. In the comparative example, 15 wt% more fuel was consumed than in Example 1.

Comparative Example 2
A method similar to that of Example 1 was employed, but the oxygen coefficients in the two combustion decompositions were different from those in Example 1. The oxygen coefficient X1 in the first combustion was 0.9, and the oxygen coefficient X3 in the second combustion was X3, so that X1 + X3 = 1.05. The remaining procedures were the same as in Example 1, and a sulfur dioxide-containing gas was obtained. The oxygen content of the sulfur dioxide-containing gas from the furnace was 2 mol%, and the _NOx content was approximately 200 mg/ ^Nm3 .

1 and 4, the auxiliary combustion air supply mechanism may further include a heating device 120 and a blower 130. The heating device has a heating housing 121 that includes a heating chamber 123 and an electric heating mechanism 122 provided within the heating chamber 123. The heating housing 121 is provided with a heating gas inlet 124 and a heating gas outlet 125 that are each connected to the heating chamber 123, the heating gas inlet 124 being connected to the blower 130, and the heating gas outlet 125 being connected to the furnace 111 of the reactor assembly. The electric heating mechanism 122 is configured to be able to increase the temperature to which the interior of the chamber 123 is heated. Because the heating gas inlet 124 is connected to the blower 130 and the heating gas outlet 125 is connected to the furnace 111 of the reactor assembly, the electric heating mechanism 122 can increase the internal temperature of the heating chamber 123. As a result, the temperature of the supporting air from the blower 130 increases as it passes through the heating device 120, and the temperature of the supporting air entering the furnace 111 reaches 600-650°C, improving the combustion efficiency of the mixed gas in the reactor assembly.

As shown in FIGS. 7 and 8, the present invention also provides:
the reactor assembly 100 for burning and reacting sulfur-containing waste to obtain a first gas containing sulfur dioxide;
a thermal energy recovery unit (300) for recovering thermal energy from the first gas to obtain a second gas;
a purification and cooling unit that purifies and cools the second gas to obtain a third gas;
a drying unit 700 for drying the third gas to obtain a fourth gas;
an oxidation-absorption unit (800) for oxidizing and absorbing the fourth gas to obtain sulfuric acid and an exhaust gas.

The specific operating process of the processing system will be described below using examples.

The water content of the sulfur-containing waste, including waste sulfuric acid and sulfur waste liquid (68.22 wt% waste sulfuric acid + 31.78 wt% sulfur-containing waste liquid), is 36 wt%. However, since the waste sulfuric acid and sulfur-containing waste liquid from the chemical fiber industry contain large amounts of particles and impurities, concentrating and dehydrating them is difficult. Therefore, they were placed in the reactor body 110 without dehydrating them.

(1) Sulfur-containing waste was atomized with a liquid spray gun using high-pressure atomizing air at 0.6 MPa and sprayed into the reactor body 110. The reaction temperature inside the furnace was set to 1,200°C, and heat was supplied using fuel (natural gas). Support combustion was performed using air with an oxygen content of 21 mol%. The room-temperature support air was pressurized with a blower 130 and then heated to 630°C with a heating device 120. The high-temperature support air was introduced into the furnace through separate support gas inlets 114 and 115. First, the sulfur-containing waste was combusted a first time with support gas introduced through the first air supply port group 114a and 115a, and then a second time with support gas introduced through the second air supply port group 114b and 115b. Here, the conditions for the first combustion include an oxygen coefficient X1 of 0.7 and a temperature of 1200°C, and the conditions for the second combustion include an oxygen coefficient X3, X1 + X3 = 1.05, a temperature of 1100°C, the content of oxygen remaining in the first gas from the furnace being 2 mol%, and the residence time of the process gas in the furnace being 5 seconds or longer.

(2) Metal dust was removed from the high-temperature process gas from the furnace using the dust collection unit 200 to obtain a dust-collected high-temperature process gas. (The operating conditions of the cyclone dust collector 210 included a feed inlet temperature of 1100°C, a feed inlet pressure of -1 kPa, and an air intake velocity at the cyclone dust collector's feed inlet of 30 m/s. The dust collection operating conditions of the ceramic membrane filter 220 included a feed inlet temperature of 1050°C, a feed inlet pressure of -1 kPa, and an air intake velocity at the ceramic membrane filter's feed inlet of 15 m/s.) The dust-collected high-temperature process gas then entered the waste heat boiler 310 to recover heat. (This was the first heat exchange, and the conditions for the first heat exchange included a tube-side flue gas pressure of -1.5 kPa, a boiler flue gas inlet temperature of 1000°C, a boiler flue gas outlet temperature of 380°C, and a shell-side steam pressure of 3.8 MPa and a temperature of 249°C.) 31 tons of 3.8 MPa saturated steam was generated per hour. The saturated steam exchanges heat with a small amount of solid-free high-temperature process gas in the steam superheater 320 (second heat exchange, conditions for which include flue gas side pressure of -1.5 kPa, heater flue gas inlet temperature of 1000°C, heater flue gas outlet temperature of 450°C, steam side pressure of 3.8 MPa, and temperature of 350°C), producing hot steam 16. The superheated steam enters the steam turbine, reducing the electrical energy of the system.

(3) The process gas after thermal energy utilization enters the rapid cooling and humidification tower 400, where it is rapidly cooled by adiabatic humidification, and the gas temperature is rapidly cooled from 400°C to 77°C. It then enters the cooling and absorption tower 500 equipped with multi-stage packing, then enters the first absorption chamber where it is washed with a circulating water cooler and cooled to 35°C, then enters the second absorption chamber where it is washed, washed with a refrigerated water cooler and cooled to 29°C. After being cooled twice, the process gas enters the electric demister 600, where sulfur trioxide acid mist is removed.

(4) The process gas from which the sulfur trioxide acid mist had been removed entered the drying unit 700 and dried with 93 wt% concentrated sulfuric acid.

(5) The dried process gas, whose sulfur dioxide content was 5 mol%, was pressurized to 20 kPa by the main blower 810 and then entered the first external heat exchanger 830 and the second heat exchange line 845b (see Figure 13) in sequence for heat exchange. After that, it entered the first conversion chamber. When the temperature of the reaction process gas 37 in the first catalyst layer 844a in the converter 840 reached 415±5°C, an oxidation reaction was initiated. When the temperature of the reaction-completed process gas reached 555±5°C, it underwent heat exchange with the gas on the tube side of the first heat exchange line 845a in the converter 840. When the temperature of the process gas in the second catalyst layer 844b reached 455±5°C, an oxidation reaction was initiated. Thus, the first oxidation reaction was initiated in the first conversion chamber, with a conversion rate of 96 mol%. The first oxidation reaction process gas 38 undergoes heat exchange through the tube side of the first external heat exchanger 830, after which its temperature is controlled to 150°C or higher. It then enters the first absorption layer of the multi-stage absorption tower 880, where it undergoes first absorption with 100 wt% sulfuric acid, with an absorption rate of 99.99 wt%.

After the first absorption, the process gas entered the second external heat exchanger 870 and the first heat exchange line 845a for heat exchange before entering the second conversion chamber. When the temperature of the reacted process gas in the third catalyst layer 844c reached 415±5°C, the oxidation reaction began. The sulfur trioxide-containing process gas, which had completed the reaction, passed through the second heat exchange line 845b for heat exchange. When the temperature of the reacted process gas in the fourth catalyst layer 844d reached 415±5°C, the oxidation reaction began. The second oxidation reaction was completed in the second conversion chamber. The total conversion rate of the four catalyst layers after the reaction was 99.92 mol%. The gas temperature of the second oxidation reaction process from the second conversion gas outlet of the converter 840 was then controlled to above 130°C and entered the second absorption layer of the multi-stage absorption tower 880 for second absorption with 98 wt% sulfuric acid, with an absorption rate of 99.99 wt%.

The process gas that has completed the second absorption is discharged to the outside, and in the discharged gas, the _SO2 concentration is 50 mg/Nm3 or ^less , the _NOx concentration is 50 mg/Nm3 ^or less, the acid mist concentration is 5 mg/Nm3 or ^less , and the particle concentration is 30 mg/Nm3 or ^less .

Figure 9 shows the connection structure between the dust collection unit 200 and the thermal energy recovery unit 300 of the sulfur-containing waste treatment system, where the thermal energy recovery unit 300 is connected downstream of the dust collection unit 200. The dust collection unit 200 includes at least two filter groups arranged in parallel, each filter group including two filters, the two filters being a cyclone dust collector 210 and a ceramic membrane filter 220, respectively, and the ceramic membrane filter 220 being connected in series downstream of the cyclone dust collector 210. The shell of the cyclone dust collector 210 is made of high-alloy steel. An insulating layer and a refractory layer are sequentially formed on the inner wall of the cyclone dust collector 210, and the insulating layer is made of lightweight castable and/or lightweight refractory brick. The refractory layer is made of at least one material selected from corundum bricks, corundum-mullite bricks, chrome-corundum bricks, and silicon carbide. The cyclone dust collector's air inlet has a spiral surface air inlet structure. The cyclone dust collector's ash outlet adopts a star-shaped ash valve structure or an overflow spiral structure. The thermal energy recovery unit 300 includes a waste heat boiler 310 and a steam superheater 320. The waste heat boiler 310 and the steam superheater 320 are both connected to the dust collection unit 200. The waste heat boiler 310 and the steam superheater 320 are also connected to each other, allowing saturated steam obtained in the waste heat boiler 310 to enter the steam superheater 320.

By combining a specific dust collection unit with a thermal energy recovery unit, sequentially installing specific heat insulating and fireproof layers on the inner wall of the cyclone dust collector, and adopting a specific device structure and combination form, the requirements for equipment handling high-temperature dust-containing flue gas (for example, sulfur dioxide-containing flue gas with a temperature of 900-1200°C discharged from a high-temperature decomposition furnace in the high-temperature combustion decomposition process of sulfur-containing waste) are met, dust collection efficiency is high, and heat loss in the dust collection device for high-temperature dust-containing flue gas is significantly reduced.

The purification and cooling unit of the sulfur-containing waste treatment system includes a quenching and humidifying tower 400, a multi-stage cooling and absorption tower 500, and an electric demister 600, which are connected in series, and the quenching and humidifying tower 400 is connected to the thermal energy recovery unit 300.

Figure 10 shows a schematic diagram of a quenching and humidifying tower 400. The quenching and humidifying tower 400 includes a first tower body 410 and a spray assembly 420. The first tower body 410 includes a cooling chamber 411, a chamber inlet 412, and a chamber outlet 413. The chamber inlet 412 and chamber outlet 413 are respectively provided on the outer wall of the first tower body 410 and communicate with the cooling chamber 411. The chamber inlet 412 is located at the bottom of the tower body 410, and the chamber outlet 413 is located at the top of the tower body 410. The spray assembly 420 is provided within the cooling chamber 411 and includes a first spray port 421 and a second spray port 422. The first spray port 421 is configured to spray cooling liquid downward, and the second spray port 422 is configured to spray cooling liquid upward, with the first spray port 421 and the second spray port 422 being opposite each other.

The first spray nozzle 421 of the spray assembly 420 is configured to spray cooling liquid downward, and the second spray nozzle 422 is configured to spray cooling liquid upward. The first spray nozzle 421 and the second spray nozzle 422 are positioned opposite each other. Therefore, when the high-temperature process gas enters the cooling chamber 411 from the chamber inlet 412 and flows to the chamber outlet 130, the cooling liquid sprayed by the first spray nozzle 421 and the second spray nozzle 422 can completely cool and reduce the temperature of the high-temperature process gas in both upward and downward directions, respectively. This also improves the humidity of the high-temperature process gas and allows it to be rapidly cooled from a high temperature of 320-350°C to 75-80°C, thereby achieving efficient and effective cooling of the process gas. The resistance generated by the system is small, typically 1 kPa, thereby shortening the treatment cycle for sulfur-containing waste.

Furthermore, the quenching and humidifying tower 400 may further include a unidirectional spray 430, which is disposed between the spray assembly 420 and the chamber outlet 413 and is configured to spray cooling liquid downward, thereby enhancing the cooling effect.

Figure 11 shows a schematic diagram of a cooling absorption tower 500. The cooling absorption tower includes a second tower body 510, a first absorption layer, and a second absorption layer. The second tower body 510 is arranged vertically and has a cooling absorption chamber extending vertically. The second tower body 510 includes a gas supply port and a gas discharge port, each of which communicates with the cooling absorption chamber. The gas supply port is located at the bottom of the second tower body 510, and the gas discharge port is located at the top of the second tower body 510. The first absorption layer and the second absorption layer are arranged vertically with a space between them within the cooling absorption chamber. The first absorption layer includes a first spray mechanism 520 capable of spraying absorption liquid into the cooling absorption chamber, and the second absorption layer includes a second spray mechanism 530 capable of spraying absorption liquid into the cooling absorption chamber.

The second tower body 510 is installed vertically and has a cooling absorption chamber extending vertically, thereby reducing the footprint of the cooling absorption tower and lowering operating costs. Furthermore, the first and second absorption layers are installed vertically spaced apart within the cooling absorption chamber. The first absorption layer includes a first spray mechanism 520 capable of spraying absorbing liquid into the cooling absorption chamber, and the second absorption layer includes a second spray mechanism 530 capable of spraying absorbing liquid into the cooling absorption chamber. Therefore, after the process gas enters the cooling absorption chamber from the gas supply port, it undergoes an absorption reaction with the absorbing liquid sprayed by the first spray mechanism 520 and the second spray mechanism 530, respectively. The absorbing liquid sufficiently absorbs the sulfur trioxide in the process gas, thereby achieving the effect of purifying the process gas.

A separator 513 may be provided in the cooling absorption chamber of the second tower body 510, dividing the cooling absorption chamber into a first chamber and a second chamber from bottom to top by the separator 513, with the first absorption layer provided in the first chamber and the second absorption layer provided in the second chamber. The second tower body 510 is provided with an intake port 511, an exhaust port 512, and a vent connecting the first and second chambers. The intake port 511 is connected to the first chamber, located at the bottom of the first chamber, and is used to receive external process gas. The exhaust port 512 is connected to the second chamber, located at the top of the second chamber, and is used to discharge the process gas to a downstream process. The first spray mechanism 520 and the second spray mechanism 530 are configured to spray absorption liquid and refrigerating liquid into the first and second chambers, respectively, with the temperature of the refrigerating liquid being lower than that of the cooling liquid. This configuration has the advantage that the refrigerating liquid can further lower the temperature of the process gas. For example, if the temperature of the cooling liquid is 28-32°C, the process gas is washed through the first absorption layer and cooled to approximately 35°C, and then further cooled with refrigerating liquid at a temperature of 7-10°C, before being washed through the second absorption layer and cooled to approximately 15°C, significantly increasing the cooling effect.

To increase the efficiency of cooling liquid utilization, save energy, and reduce production costs, the cooling absorption tower 500 includes a water pump 560 and a cooler 570, which cool the absorption liquid and refrigeration liquid before recirculating them into the cooling chamber.

To ensure more thorough contact between the absorbing liquid and the process gas, the first absorption layer may include a first packing 540, a first spray mechanism 520 configured to spray the absorbing liquid downward, and the first packing 540 located below the first spray mechanism 520. The second absorption layer may include a second packing 550, a second spray mechanism 530 configured to spray the absorbing liquid downward, and the second packing 550 located below the second spray mechanism 530. It should be understood that the packings can be made of various materials as long as they ensure more thorough contact between the absorbing liquid and the process gas. In one embodiment, the first packing 540 and the second packing 550 are polypropylene helix rings.

After undergoing drying treatment in the purification, cooling, and drying unit 700, the process gas is introduced into the oxidation and absorption unit 800, where the sulfur dioxide contained therein is converted to sulfur trioxide, which is then absorbed to form sulfuric acid. Figure 12 shows a schematic diagram of the oxidation and absorption unit 800, and Figure 13 is a structural schematic diagram of the converter 840 of the oxidation and absorption unit 800.

The oxidation-absorption unit 800 includes a converter and an absorber. The converter is connected to the drying unit 700 and is used to oxidize sulfur dioxide in the fourth gas obtained in the drying unit 700 to obtain a sulfur trioxide-containing gas. The absorber is connected to the converter and is used to absorb the sulfur trioxide-containing gas to obtain sulfuric acid and exhaust gas. Specifically, in the illustrated preferred embodiment, the oxidation-absorption unit 800 includes a first external heat exchanger 830, a second external heat exchanger 870, a multi-stage absorption tower 880, a first heat exchanger 850, a second heat exchanger 860, a sulfuric acid cooler 890, an absorption circulation pump, and a converter 840 provided with first heat exchange pipes 845a and second heat exchange pipes 845b. Dotted lines represent heating pipes, solid lines represent process pipes, and arrows represent the flow direction of the medium during heating. Specifically, the medium flows as follows: The process gas is sent to the temperature-raising furnace 820 by the blower 810, then enters the first external heat exchanger 830, then the converter 840, then the second external heat exchanger 870, and finally returns to the blower 810 via the second heat exchanger 860, thus completing the circulation. During this temperature-raising process, the medium circulates through the blower 810, the temperature-raising furnace 820, and the converter 840, but does not enter the multi-stage absorption tower 880. Although the temperature-raising pipeline and the process pipeline partially overlap, this does not affect the normal flow of the process.

The converter 840 shown in Figure 13 includes a converter housing 841, a catalyst layer assembly, and heat exchange lines 845a and 845b, and has a conversion chamber inside the converter housing 841. The converter housing 841 has converted gas inlets 842a and 842b and converted gas outlets 843a and 843b, which respectively communicate with the conversion chamber. The catalyst layer assembly includes at least two catalyst layers 844a, 844b, 844c, and 844d. The multiple catalyst layers are provided in the conversion chamber and spaced apart in the flow direction of the process gas. The number of heat exchange lines 845a and 845b matches the number of catalyst layers 844a, 844b, 844c, and 844d. The heat exchange lines are at least partially located in the conversion chamber and are provided between two adjacent catalyst layers. The heat exchange line is configured to be located in the conversion chamber and is provided between two adjacent catalyst layers, significantly reducing the space occupied and effectively lowering usage costs.

Specifically, the converter 840 includes a first conversion chamber and a second conversion chamber formed within a converter housing 841, a first catalyst layer 844a, a second catalyst layer 844b, a third catalyst layer 844c, a fourth catalyst layer 844d, a first converted gas inlet 842a, a second converted gas inlet 842b, a first converted gas outlet 843a, and a second converted gas outlet 843b. The first converted gas inlet 842a and the first converted gas outlet 843a are all connected to the first conversion chamber, whereby the process gas flows from the first converted gas inlet 842a to the first converted gas outlet 843a. The second converted gas inlet 842b and the second converted gas outlet 843b are all connected to the second conversion chamber, allowing the process gas to flow from the second converted gas inlet 842b to the second converted gas outlet 843b. The first catalyst layer 844a and the second catalyst layer 844b are all located within the first conversion chamber and are spaced apart in the flow direction of the process gas. The third catalyst layer 844c and the fourth catalyst layer 844d are all located within the second conversion chamber and are spaced apart in the flow direction of the process gas.

In the present invention, the process gas enters the first conversion chamber through the first conversion gas inlet 842a, reacts first with the first catalyst layer 844a, then with the second catalyst layer 844b, and after the reaction is complete, directly enters the external heat exchanger through the first conversion gas outlet 843a. The sulfur trioxide-containing process gas that has completed the reaction is heat exchanged in the external heat exchanger to control its temperature to 150°C or higher, and then enters the first stage of the multi-stage absorption tower. The conversion rate of the first conversion is 95-96%, and when absorbed with 100 wt% sulfuric acid, the absorption rate is 99.99%. The absorbed process gas then passes through an external heat exchanger for heat exchange. The heat-exchanged process gas reaches a temperature of 415-420°C and enters the second conversion chamber through the second conversion gas inlet 842b. The sulfur trioxide-containing process gas then undergoes heat exchange in the second heat exchange line 845b and reacts with the fourth catalyst layer 844d. The temperature of the reacted process gas is controlled to 130°C or higher and enters the second stage of the multi-stage absorption tower through the second conversion gas outlet 843b. The absorption rate is 99.99%, and the absorbed process gas is discharged to the outside. The _SO2 concentration is 50 mg/ ^m3 or less, the _NOx concentration is 100 mg/m3 or ^less , the acid mist is 5 mg/m3 ^or less, and the particulate concentration is 30 mg/m3 or ^less . Therefore, the converter of the present invention has the advantage of high conversion efficiency.

To stably position each catalyst layer within the conversion chamber, in one embodiment of the present invention, the converter 840 includes multiple support assemblies corresponding to the first, second, third, and fourth catalyst layers 844a, 844b, 844c, and 844d, respectively. The support assemblies include a grid plate 846, the edges of which are connected to the inner wall of the converter housing 841 to support the catalyst layers. The support assemblies also include heat-resistant ceramic balls 847 located on the side of the catalyst layer away from the grid plate 846. In this embodiment, the primary function of the heat-resistant ceramic balls 847 is to press down on the catalyst layer, ensuring a flat coating on the grid plate 846 and preventing the catalyst layer from being blown away by airflow. The heat-resistant ceramic balls 847 also exchange heat with the process gas passing through them, lowering the temperature of the process gas to a temperature suitable for reaction with the catalyst layers, while also absorbing impurity particles in the process gas, thereby purifying the process gas.

Based on the above-mentioned reactor assembly and sulfur-containing waste treatment system, the present invention also provides a method for burning sulfur-containing waste and a method for producing sulfuric acid by regenerating sulfur-containing waste. The sulfur-containing waste to be burned may be waste sulfuric acid, sulfur-containing waste liquid, sulfur-containing waste gas, etc., and the fuel may be at least one selected from natural gas, sulfur, liquefied hydrocarbons, hydrogen sulfide, and heavy oil organic matter. The process gas from the combustion has a sulfur dioxide content of 3 to 12 mol%, a _NOx content of 100 mg/ ^m3 or less, and an oxygen content of 0.5 to 5 mol%.

The above describes in detail preferred embodiments of the present invention with reference to the drawings, but the present invention is not limited thereto. Various simple modifications of the technical solutions of the present invention may be made within the scope of the technical concept of the present invention, and to avoid unnecessary duplication, the present invention does not separately describe various possible combinations. However, these simple modifications and combinations should also be considered as part of the disclosure of the present invention, and all fall within the patentable scope of the present invention.

[Explanation of symbols]
100 Reactor assembly 110 Reactor body 111 Furnace 112 Fuel gas inlet 113 Process gas outlet 114 First auxiliary combustion air inlet 115 Second auxiliary combustion air inlet 116 Liquid spray gun 120 Heating device 121 Heating housing 122 Electric heating mechanism 123 Heating chamber 124 Heating gas inlet 125 Heating gas outlet 130 Blower 200 Dust collection unit 210 Cyclone dust collector 220 Ceramic membrane filter 300 Thermal energy recovery unit 310 Waste heat boiler 320 Steam superheater 400 Quench and humidification tower 410 First tower body 411 Cooling chamber 412 Chamber inlet 413 Chamber outlet 420 Spray assembly 421 First spray nozzle 422 Second spray nozzle 430 Unidirectional spray 500 Cooling absorption tower 510 Second tower body 511 Air inlet 512 Air outlet 513 Separator 520 First spray mechanism 530 Second spray mechanism 540 First packing 550 Second packing 560 Water pump 570 Cooler 600 Electric demister 700 Drying unit 800 Oxidation absorption unit 810 Blower 820 Heating furnace 830 First external heat exchanger 840 Converter 841 Converter housing 842a First converted gas inlet 842b Second converted gas inlet 843a First converted gas outlet 843b Second converted gas outlet 844a First catalyst layer 844b Second catalyst layer 844c Third catalyst layer 844d Fourth catalyst layer 845a First heat exchange line 845b Second heat exchange pipe 846: lattice plate 847: heat-resistant ceramic balls 850: first heat exchanger 860: second heat exchanger 870: second external heat exchanger 880: multi-stage absorption tower 890: sulfuric acid cooler

FIG. 1 is a schematic diagram of a reactor assembly in one embodiment of the present invention. FIG. 2 is a side view of the furnace of the reactor assembly of the present invention. FIG. 2 is a front view of the furnace of the reactor assembly of the present invention. 1 is a schematic diagram of a heating device for a reactor assembly of the present invention; 2 is a flowchart of a reactor combustion control method for a sulfur-containing waste treatment system according to an embodiment of the present invention. 2 is a flowchart of a reactor combustion control method for a sulfur-containing waste treatment system according to an embodiment of the present invention. 1 is a process flow diagram of a sulfur-containing waste treatment system according to an embodiment of the present invention. 1 is a flowchart of a method for producing sulfuric acid by regenerating sulfur-containing waste according to the present invention. FIG. 2 is a schematic diagram of a dust collection unit and a thermal energy recovery unit. FIG. 1 is a schematic diagram of a quenching and humidifying tower. FIG. 1 is a schematic diagram of a cooling absorption tower. FIG. 1 is a schematic diagram of an oxidation absorption unit. FIG. 1 is a schematic diagram of a converter.

Claims (16)

1. A reactor assembly comprising:
a reactor body (110) including a cylindrical furnace (111) for receiving sulfur-containing waste and carrying out a combustion reaction therein, and a fuel gas inlet (112) and a process gas outlet (113) respectively communicating with the furnace (111), the fuel gas inlet (112) and the process gas outlet (113) being provided at both ends of the furnace (111) along the axial direction of the furnace (111) with a space therebetween, and the fuel gas inlet (112) being configured so that fuel flowing along the axial direction of the furnace (111) can be supplied to the furnace (111);
a combustion supporting air supply mechanism configured to supply the combustion supporting air flowing along the circumferential direction of the inner wall of the furnace (111) to the furnace (111);
The combustion supporting air supply mechanism includes a plurality of combustion supporting air supply ports spaced apart along the axial direction of the furnace (111),
the plurality of auxiliary combustion air supply port groups include a first air supply port group (114a, 115a) and a second air supply port group (114b, 115b), the first air supply port group (114a, 115a) being provided close to the fuel gas inlet (112), and the second air supply port group (114b, 115b) being provided close to the process gas outlet (113);
The reactor assembly includes a control device for controlling the auxiliary combustion air supply mechanism, configured to control air to enter through the first air supply port group (114a, 115a) and to control the amount of oxygen at the position of the first air supply port group (114a, 115a) to be a first oxygen amount, and to control the air to enter through the second air supply port group (114b, 115b) and to control the amount of oxygen at the position of the second air supply port group (114b, 115b) to be a second oxygen amount that is a theoretical oxygen amount for normal combustion of sulfur-containing waste and is greater than the first oxygen amount, and further to control the fuel and the sulfur-containing waste to be combusted to perform at least two combustions, including a first combustion corresponding to the first oxygen amount and a second combustion corresponding to the second oxygen amount,
The plurality of air supply port groups include at least one third air supply port group provided between the first air supply port group (114a, 115a) and the second air supply port group (114b, 115b),
the control device is further configured to control the air to enter through the third group of air supply ports so that the amount of oxygen at the third group of air supply ports is less than the second amount of oxygen;
in the first combustion, the oxygen coefficient is X1 and the temperature is 1100-1250°C; in the final combustion, the oxygen coefficient is X3 and the temperature is 1000-1100°C; in the subsequent combustions, the oxygen coefficients are each independently X2 and the temperatures are each independently 1100-1200°C; and 0.5≦X1≦0.85, 0.7≦X1+X2≦1, 1≦X1+X2+X3≦1.15;
10. A reactor assembly according to claim 9, wherein the oxygen coefficient is the ratio of the oxygen-containing combustion support gas converted to the oxygen molar content to the oxygen molar content required for complete combustion of the fuel. The reactor assembly of claim 1, characterized in that the supporting air supply mechanism includes a first supporting air inlet (114) and a second supporting air inlet (115) opened in the reactor body (110) and each communicating with the furnace (111), the first supporting air inlet (114) and the second supporting air inlet (115) being configured to supply supporting air to the furnace (111) along a tangential direction of the furnace (111) at various positions in the circumferential direction of the furnace (111), and the flow direction of the supporting air supplied by the first supporting air inlet (114) and the flow direction of the supporting air supplied by the second supporting air inlet (115) being the same. The reactor assembly of claim 1, wherein the first amount of oxygen is 60% of the second amount of oxygen. The auxiliary combustion air supply mechanism includes a heating device (120) including a heating housing (121) and an electric heating mechanism (122);
The heating housing (121) has a heating chamber (123) therein, and the heating housing (121) has a heating gas inlet (124) and a heating gas outlet (125) which are connected to the heating chamber (123), respectively, the heating gas inlet (124) is connected to an external gas source, and the heating gas outlet (125) is connected to the furnace (111) to supply the auxiliary combustion air to the furnace (111);
The reactor assembly of claim 1, wherein the electric heating mechanism (122) is configured to increase the temperature inside the heating chamber (123). 1. A sulfur-containing waste treatment system, comprising:
A reactor assembly (100) according to any one of claims 1 to 4, which is adapted to combust and react sulfur-containing waste to obtain a first gas comprising sulfur dioxide;
a thermal energy recovery unit (300) for recovering thermal energy from the first gas to obtain a second gas;
a purification and cooling unit that purifies and cools the second gas to obtain a third gas;
a drying unit (700) for drying the third gas to obtain a fourth gas;
an oxidation-absorption unit (800) that oxidizes and absorbs the fourth gas to obtain sulfuric acid and an exhaust gas. The sulfur-containing waste treatment system of claim 5, further comprising a dust collection unit (200) disposed between the reactor assembly (100) and the thermal energy recovery unit (300), wherein the first gas obtained by the reactor assembly (100) first enters the dust collection unit (200) for dust collection, and then enters the thermal energy recovery unit (300) to recover the thermal energy and obtain the second gas. The sulfur-containing waste treatment system of claim 6, characterized in that the dust collection unit (200) includes at least two filter groups arranged in parallel, and each filter group includes at least one filter. The sulfur-containing waste treatment system of claim 6, characterized in that the thermal energy recovery unit (300) includes a waste heat boiler (310) and a steam superheater (320), both of which are connected to the dust collection unit (200) so that the process gas obtained by the dust collection unit (200) enters the waste heat boiler (310) and the steam superheater (320), respectively, and the waste heat boiler (310) and the steam superheater (320) are connected to each other so that saturated steam obtained by the waste heat boiler (310) enters the steam superheater (320). The sulfur-containing waste treatment system described in claim 5, characterized in that the purification and cooling unit includes a quenching and humidifying tower (400), a multi-stage cooling and absorption tower (500), and an electric demister (600) that are connected in series, and the quenching and humidifying tower (400) and the thermal energy recovery unit (300) are connected in series. The quench and humidification tower (400) includes a first tower body (410) and a spray assembly (420);
The first column body (410) includes a cooling chamber (411), a chamber inlet (412), and a chamber outlet (413), the chamber inlet (412) and the chamber outlet (413) are respectively opened in the outer wall of the first column body (410) and communicate with the cooling chamber (411), the chamber inlet (412) is located at the bottom of the first column body (410) and receives process gas from the process gas outlet (113) of the reactor assembly (100), and the chamber outlet (413) is located at the top of the first column body (410);
10. The sulfur-containing waste treatment system of claim 9, wherein the spray assembly (420) is provided within the cooling chamber (411), the spray assembly (420) includes a first spray port (421) and a second spray port (422), the first spray port (421) is configured to spray cooling liquid downward, and the second spray port (422) is configured to spray cooling liquid upward, and the first spray port (421) and the second spray port (422) are provided opposite each other. The cooling absorption tower (500) includes a second tower body (510), a first absorption layer, and a second absorption layer,
the second column body (510) is arranged vertically and has a cooling absorption chamber extending vertically, the second column body (510) includes a gas inlet and a gas outlet each communicating with the cooling absorption chamber, the gas inlet being arranged at a lower part of the second column body and receiving process gas from a process gas outlet (113) of the reactor assembly (100), and the gas outlet being arranged at an upper part of the second column body (510);
10. The sulfur-containing waste treatment system of claim 9, wherein the first absorption layer and the second absorption layer are spaced apart along a vertical direction within the cooling absorption chamber, the first absorption layer including a first spray mechanism (520) capable of spraying absorption liquid into the cooling absorption chamber, and the second absorption layer including a second spray mechanism (530) capable of spraying absorption liquid into the cooling absorption chamber. The oxidation absorption unit (800) includes a converter and an absorber;
the conversion device is in communication with the drying unit (700) and is used to oxidize the fourth gas obtained by the drying unit (700) to obtain a sulfur trioxide-containing gas;
6. The sulfur-containing waste treatment system according to claim 5, wherein the absorption device is connected to the conversion device and is used to absorb and treat the sulfur trioxide-containing gas to obtain the sulfuric acid and the exhaust gas. The conversion device includes a converter (840), the converter including a converter housing (841), a catalyst bed assembly, and heat exchange lines (845a, 845b);
The converter housing (841) has a conversion chamber therein, and the converter housing (841) has conversion gas inlets (842a, 842b) and conversion gas outlets (843a, 843b) respectively communicating with the conversion chamber, and the conversion gas inlets (842a, 842b) are used to receive process gas from the process gas outlet (113) of the reactor assembly (100);
The catalyst layer assembly includes at least two catalyst layers (844a, 844b, 844c, 844d), and the plurality of catalyst layers (844a, 844b, 844c, 844d) are provided in the conversion chamber and spaced apart along the flow direction of the process gas;
13. The sulfur-containing waste treatment system according to claim 12, wherein the number of the heat exchange lines (845a, 845b) is adapted to the number of the catalyst layers (844a, 844b, 844c, 844d), and the heat exchange lines (845a, 845b) are at least partially located within the conversion chamber and are provided between two adjacent catalyst layers (844a, 844b, 844c, 844d). A method for burning sulfur-containing waste using the reactor assembly described in any one of claims 1 to 4. A method for producing sulfuric acid by regenerating sulfur-containing waste, comprising:
15. The method of claim 14, comprising the steps of: (1) introducing fuel and the sulfur-containing waste into the reactor assembly in the presence of an oxygen-containing combustion supporting gas to perform at least two combustions to obtain a first gas containing sulfur dioxide;
(2) introducing the first gas into a thermal energy recovery unit to recover thermal energy and obtain superheated steam and a second gas;
(3) introducing the second gas into a purification and cooling unit for purification and cooling to obtain a third gas;
(4) introducing the third gas into a drying unit to dry it and obtain a fourth gas;
and (5) introducing the fourth gas into an oxidation absorption unit for oxidation absorption to obtain sulfuric acid and exhaust gas. The sulfur-containing waste is at least one selected from waste sulfuric acid, sulfur-containing waste liquid, and sulfur-containing waste gas;
The fuel is at least one selected from natural gas, sulfur, liquid hydrocarbons, hydrogen sulfide, and heavy oil organics;
16. The method according to claim 15, wherein the first gas has a sulfur dioxide content of 3 to 12 mol ^% , a _NOx content of 100 mg/Nm3 or less, and an oxygen content of 0.5 to 5 mol%.