CA3199289A1

CA3199289A1 - Reactor assembly, sulfur-containing waste treatment system, method for burning sulfur-containing waste, and method for making sulfuric acid by regenerating sulfur-containing waste

Info

Publication number: CA3199289A1
Application number: CA3199289A
Authority: CA
Inventors: Xiaoyan Xu; Lan Wei; Yingbin CHEN; Xuewen Wang; Biqing JIANG
Original assignee: China Petroleum and Chemical Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Current assignee: China Petroleum and Chemical Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Priority date: 2020-10-23
Filing date: 2021-10-22
Publication date: 2022-04-28
Also published as: WO2022083737A1; JP2023547861A

Abstract

Disclosed in the present invention are a reactor assembly and a sulfur-containing waste treatment system. The reactor assembly comprises a hearth for performing a combustion reaction on a sulfur-containing waste mixed liquor, the hearth is of a cylindrical structure, the reactor assembly is provided with a fuel gas inlet and a process gas outlet in communication with the hearth, the fuel gas inlet and the process gas outlet are arranged at the two ends of the hearth at intervals along the axial direction of the hearth, the fuel gas inlet is configured to be able to provide the hearth with a fuel gas flowing along the axial direction of the hearth, the reactor assembly comprises a combustion air supply mechanism, and the combustion air supply mechanism is configured to be able to provide the hearth with combustion air flowing along the circumferential direction of the inner wall of the hearth.

Description

Reactor Assembly, Sulfur-Containing Waste Treatment System, Method for Burning Sulfur-Containing Waste, and Method for Making Sulfuric Acid by Regenerating Sulfur-Containing Waste CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefits of the Chinese Patent Application Nos.
202011148953.4 and 202011150297.1 filed on Oct. 23, 2020 and the Chinese Patent Application Nos. 202110739636.8, 202110736744.X, 202110736751.X, 202110736752.4, 202121481507.5 and 202110736743.5 filed on Jun. 30, 2021, all of which are incorporated herein by reference.
FIELD
The present disclosure relates to sulfur-containing waste treatment, in particular to a reactor assembly, a sulfur-containing waste treatment system, a method for burning sulfur-containing waste and a method for making sulfuric acid by regenerating sulfur-containing waste.
BACKGROUND
Concentrated sulfuric acid is widely used as a catalyst in the processes in the petrochemical and organic synthesis industries, in which a large amount of waste sulfuric acid is produced. In some organic synthesis processes, such as methyl methacrylate (MMA) synthesis process and acrylonitrile (AN) synthesis process, about 30 wt% - 45 wt% waste ammonium sulfate is produced, in addition to waste sulfuric acid. These sulfur-containing wastes may cause serious environmental pollution. Therefore, it is necessary to purify industrial waste acids and sulfur-containing waste liquors and recycle them as much as possible.
Existing sulfur-containing waste treatment methods mainly include high-temperature concentration, solvent extraction, alkali neutralization, chemical oxidation, and high-temperature combustion cracking, etc. At present, although the high-temperature combustion method is thorough and clean, it has some drawbacks, such as low combustion efficiency, high operating cost and complicated operation.

Date recue/Date received 2023-04-20 SUMMARY
To overcome the drawbacks in the prior art, the present disclosure provides a reactor assembly and a sulfur-containing waste treatment system. The reactor assembly can burn and treat sulfur-containing waste and inhibit the generation of nitrogen oxides.
To attain the above object, the present disclosure provides a reactor assembly, which comprises a reactor body having a hearth for performing a combustion reaction of sulfur-containing waste and a fuel gas inlet and a process gas outlet that are in communication with the hearth, wherein the hearth is of a cylindrical structure, the fuel gas inlet and the process gas outlet are arranged spaced apart from each other at two ends of the hearth in an axial direction of the hearth, and .. the fuel gas inlet is configured to be able to supply the hearth with fuel flowing in the axial direction of the hearth; the reactor assembly comprises a combustion air supply mechanism, which is configured to be able to supply the hearth with combustion air flowing in the circumferential direction of the inner wall of the hearth.
Optionally, the combustion air supply mechanism comprises a plurality of groups of combustion air inlets that are arranged at intervals in the axial direction of the hearth.
Optionally, the plurality of groups of combustion air inlets comprise a first group of combustion air inlets and a second group of combustion air inlets, wherein the first group of combustion air inlets are arranged near the fuel gas inlet, and the second group of combustion air inlets are arranged near the process gas outlet; the reactor assembly comprises a control device for controlling the combustion air supply mechanism, and the control device is configured to:
control the air to enter via the first group of combustion air inlets, so that the oxygen content at the first group of combustion air inlets is a first oxygen content; and control the air to enter via the second group of combustion air inlets, so that the oxygen content at the second group of combustion air inlets is a second oxygen content, wherein the second oxygen content is equal to a theoretical oxygen demand of a normal combustion process of the sulfur-containing waste, the first oxygen content is smaller than the second oxygen content, and the first oxygen content and the second oxygen content are controlled so that the fuel and the sulfur-containing waste to be burned have combustion for at least two times, including a first combustion corresponding to the first oxygen content and a second combustion corresponding to the second oxygen

2 Date recue/Date received 2023-04-20 content, thereby a gas containing sulfur dioxide is obtained finally.
Optionally, the first combustion has an oxygen coefficient X1 and a temperature of 1,100-1,250 C; the last combustion has an oxygen coefficient X3 and a temperature of 1,000-1,100 C;
the optional remaining combustions have an oxygen coefficient X2 and a temperature of .. 1,100-1,200 C respectively and independently, and 0.5<X1<0.85, 0.7<X1+X2<1, and l<X1+X2+X3<1.15; the oxygen coefficient refers to a ratio of the molar volume of the oxygen-containing combustion gas measured in the molar content of oxygen to the molar content of oxygen required for complete combustion of the fuel.
According to the above technical scheme, the fuel gas can enter the hearth through the fuel gas .. inlet and flow in the axial direction of the hearth; at the same time, the combustion air supplied by the combustion air supply mechanism to the hearth flows in the circumferential direction of the inner wall of the hearth; thus, the mixture of fuel gas and combustion air flows in a spiral form toward the process gas outlet. Therefore, in the spiral flow process, the residence time of the gas mixture in the hearth is longer, and the gas mixture has a combustion reaction with the mixed liquor of sulfur-containing waste extensively, thereby the combustion efficiency of the reactor assembly is improved. Moreover, since the detention time of the gas mixture in the hearth is longer, the distance between the fuel gas inlet and the process gas outlet can be shortened relatively, so that the reactor assembly in the present disclosure can be miniaturized.
The present disclosure further provides a sulfur-containing waste treatment system, which comprises:
the reactor assembly described above, which is configured to enable the sulfur-containing waste to perform a combustion reaction, so as to obtain a first gas containing sulfur dioxide; a heat recovery unit configured to recover heat from the first gas to obtain a second gas; a purifying and cooling unit configured to purify and cool down the second gas to obtain a third gas; and a drying unit configured to dry the third gas to obtain a fourth gas; an oxidation and absorption unit configured to oxidize and absorb the fourth gas to obtain sulfuric acid and exhaust gas.
According to the above technical scheme, with the sulfur-containing waste treatment system and the reactor assembly provided by the present disclosure, combustion in a lean-oxygen

3 Date recue/Date received 2023-04-20 environment is carried out first in the reactor to inhibit the generation of nitrogen oxides; then combustion in a rich-oxygen environment is carried out at the terminal to complete the expected combustion process; however, since the temperature at the terminal is relatively low, the generation of nitrogen oxides is also inhibited. Since nitrogen oxides are reduced, the content of sulfur dioxide in the process gas can be increased; in addition, since the expected combustion process is completed, there is no adverse effect on the normal process.
The present disclosure further provides a method based on the above reactor assembly for burning sulfur-containing waste and a method based on the above sulfur-containing waste treatment system for making sulfuric acid by regenerating sulfur-containing waste.
The present disclosure attains the following beneficial effects: the present disclosure provides optimized and improved process and device for mixed treatment of waste sulfuric acid, sulfur-containing solid waste, sulfur-containing liquid waste and sulfur-containing gas waste, with which the process flow is shortened as far as possible, less equipment is required, the operation is simpler, and the utilization ratio of heat energy is higher. The sulfur element in the raw material is regenerated into 93%-100% sulfuric acid and fuming sulfuric acid.
BRIEF DESCRITION OF THE DRAWINGS
Fig. 1 is a schematic diagram of the reactor assembly in an embodiment of the present disclosure;
Fig. 2 is a side view of the hearth of the reactor assembly in the present disclosure;
Fig. 3 is a front view of the hearth of the reactor assembly in the present disclosure;
Fig. 4 is a schematic diagram of the heating device of the reactor assembly in the present disclosure;
Fig. 5 is a flow chart of the reactor combustion control method of the sulfur-containing waste treatment system provided in an embodiment of the present disclosure;
Fig. 6 is a flow chart of the reactor combustion control method of the sulfur-containing waste treatment system provided in an embodiment of the present disclosure;
Fig. 7 is a process flow diagram of the sulfur-containing waste treatment system in an embodiment of the present disclosure;

4 Date recue/Date received 2023-04-20 Fig. 8 is a flow chart of the method for making sulfuric acid by regenerating sulfur-containing waste in the present disclosure;
Fig. 9 is a schematic diagram of the dust removal unit and the heat recovery unit;
Fig. 10 is a schematic diagram of the quenching and humidifying column;
Fig. 11 is a schematic diagram of the cooling and absorption column;
Fig. 12 is a schematic diagram of the oxidation and absorption unit; and Fig. 13 is a schematic diagram of a converter.
Reference Numbers 100 - reactor assembly; 110 - reactor body; 111 - hearth; 112 - fuel gas inlet; 113 - process gas outlet; 114 - first combustion air inlet; 115 - second combustion air inlet;
116 - fluid sprayer 120 - heating device; 121 - heating shell; 122 - electric heating mechanism;
123 - heating chamber; 124 - heating gas inlet; 125 - heating gas outlet; 130 - blower fan;
200 - dust removal unit; 210 - cyclone dust collector; 220 - ceramic membrane filter;
300 - heat recovery unit; 310 - waste heat boiler; 320 - steam superheater;
400 - quenching and humidifying column; 410 - first column body; 411 - cooling chamber; 412 - chamber inlet; 413 - chamber outlet; 420 - spraying assembly; 421 - first spraying port; 422 -second spraying port; 430 - unidirectional spray head;
500 - cooling and absorption column; 510 - second column body; 511 - gas inlet; 512 - gas outlet; 513 - partition; 520 - first spraying mechanism; 530 - second spraying mechanism; 540 .. - first filler; 550 - second filler; 560 - water pump; 570 - cooler;
600 - electrostatic mist precipitator;
700 - drying unit;
800 - oxidation and absorption unit; 810 - blower fan; 820 - heating furnace;
830 - first external heat exchanger; 840 - converter; 841 - converter shell; 842a - first conversion gas inlet; 842b -second conversion gas inlet; 843a - first conversion gas outlet; 843b - second conversion gas

5 Date recue/Date received 2023-04-20 outlet; 844a - first catalyst layer; 844b - second catalyst layer; 844c -third catalyst layer; 844d - fourth catalyst layer; 845a - first heat exchange pipeline; 845b - second heat exchange pipeline;
846 - grating; 847 - heat-resistant ceramic ball; 850 - first heat exchanger;
860 - second heat exchanger; 870 - second external heat exchanger; 880 - multi-stage absorption column; 890 -sulfuric acid cooler.
DETAILED DESCRIPTION
Hereunder some embodiments of the present disclosure will be detailed with reference to the accompanying drawings. It should be understood that the embodiments described herein are only provided to describe and explain the present disclosure, but are not intended to constitute any limitation to the present disclosure.
As shown in Figs. 1-3, the reactor assembly in the present disclosure comprises a reactor body 100, which has a hearth 111 for the sulfur-containing waste to perform a combustion reaction, and the hearth 111 is of a cylindrical structure. The reactor body 100 is further provided with a fuel gas inlet 112 and a process gas outlet 113 that are in communication with the hearth 111.
The fuel gas inlet 112 and the process gas outlet 113 are arranged space apart from each other at the two ends of the hearth 111 in the axial direction of the hearth 111, and the fuel gas inlet 112 is configured to supply the hearth 111 with a fuel gas flowing in the axial direction of the hearth 111. The reactor assembly 100 further comprises a combustion air supply mechanism, which is configured to be able to supply the hearth 111 with combustion air flowing in the circumferential direction of the inner wall of the hearth 111.
In the present disclosure, the fuel gas can enter the hearth 111 through the fuel gas inlet 112 and flow in the axial direction of the hearth 111; at the same time, the combustion air supplied by the combustion air supply mechanism to the hearth 111 flows in the circumferential direction of the inner wall of the hearth 111; thus, the mixture of fuel gas and combustion air flows in a spiral form (as shown in Fig. 2) toward the process gas outlet 113. Therefore, in the spiral flow process, the residence time of the gas mixture in the hearth 111 is longer, and the gas mixture has a combustion reaction with the mixed liquor of sulfur-containing waste extensively, thereby the combustion efficiency of the reactor assembly is improved. Moreover, since the detention time of the gas mixture in the hearth 111 is longer, the distance between the fuel gas inlet 112

6 Date recue/Date received 2023-04-20 and the process gas outlet 113 can be shortened relatively, so that the reactor assembly in the present disclosure can be miniaturized.
It should be understood that the combustion air supply mechanism can be designed in a variety of forms to drive the combustion air to flow in the circumferential direction of the inner wall of the hearth 111. For example, the combustion air supply mechanism may comprise a combustion air nozzle for supplying combustion air into the hearth 111, and a draft fan arranged in the hearth 111 to change the flow direction of the combustion air, so that the combustion air can flow in the circumferential direction of the inner wall of the hearth 111 under a drafting effect of the draft fan after it flows out of the combustion air nozzle. In order to further reduce the cost and simplify the structure of the reactor assembly, in an embodiment of the present disclosure, the combustion air supply mechanism comprises a group of combustion air inlets, including a first combustion air inlet 114 and a second combustion air inlet 115 in communication with the hearth 111 respectively. The first combustion air inlet 114 and the second combustion air inlet 115 are configured to supply the hearth 111 with combustion air flowing in a tangential direction of the hearth 111 respectively, and the flow direction of the combustion air supplied via the first combustion air inlet 114 is the same as the flow direction of the combustion air supplied via the second combustion air inlet 115. Since both the first combustion air inlet 114 and the second combustion air inlet 115 are arranged in a tangential direction of the inner wall of the hearth 111, both the combustion air jetted from the first combustion air inlet 114 and the combustion air jetted from the second combustion air inlet 115 can flow in the circumferential direction of the inner wall of the hearth 111, thereby other parts can be omitted, and the structure is simplified and can be serviced more conveniently.
Of course, in addition to the first combustion air inlet 114 and the second combustion air inlet 115, the group of combustion air inlets may further include a third combustion air inlet, and a fourth combustion air inlet, etc. All these combustion air inlets are positioned in the same radial plane of the hearth 111 and arranged in the same orientation (i.e., clockwise or counterclockwise), so as to ensure that the gas mixture flows in a spiral form in the hearth 111.
It should be noted that in an embodiment of the present disclosure, as shown in Figs. 2 and 3, both the opening direction of the first combustion air inlet 114 and the opening direction of the

7 Date recue/Date received 2023-04-20 second combustion air inlet 115 are perpendicular to the axial direction of the hearth 111, which is to way, the flow direction of the fuel gas is perpendicular to a plane formed by the flow direction of the combustion air. In another embodiment of the present disclosure, both the opening direction of the first combustion air inlet 114 and the opening direction of the second combustion air inlet 115 are inclined toward the fuel gas inlet 112. An advantage of such an arrangement is that the flow direction of the combustion air into the hearth 111 is opposite to the flow direction of the fuel gas, thereby the combustion air and the fuel gas can be mixed more extensively, and the flow speed of the gas mixture is decreased, thus the duration of flow of the gas mixture in the hearth 111 is further increased, thereby the reactor assembly can be further miniaturized. Of course, the opening direction of the first combustion air inlet 114 and the opening direction of the second combustion air inlet 115 only has to be slightly inclined toward the fuel gas inlet 112; for example, they can be inclined by 20-40 degrees toward the fuel gas inlet 112.
In order to supply the combustion air more plentifully, in an embodiment of the present disclosure, as shown in Fig. 2, the combustion air supply mechanism includes a plurality of groups of combustion air inlets, which are arranged at intervals in the axial direction of the hearth 111. In the illustrated preferred embodiment, the reactor body 100 is provided with two above-mentioned first combustion air inlets 114 and two above-mentioned second combustion air inlets 115 respectively, wherein the combustion air inlets 114a and 115a near the fuel gas inlet 112 constitute a first group of combustion air inlets, and combustion air inlets 114b and 115b near the process gas outlet 113 constitute a second group of combustion air inlets. Thus, the combustion of the sulfur-containing waste can be controlled by controlling the amount of combustion air introduced into the hearth 111 via the first group of combustion air inlets and the second group of combustion air inlets.
Specifically, as illustrated in the flow chart of the method for reactor combustion control of the sulfur-containing waste treatment system shown in Fig. 5, the method comprises:
Step Sll: detecting the oxygen content at the first group of combustion air inlets and the second group of combustion air inlets;
For example, oxygen sensors may be provided at the first group of combustion air inlets and

8 Date recue/Date received 2023-04-20 the second group of combustion air inlets to detect the oxygen content.
Step S12: controlling the air to enter into the first group of combustion air inlets, so that the oxygen content at the first group of combustion air inlets is a first oxygen content;
For example, air can be supplemented/reduced at the first group of combustion air inlets with reference to the oxygen content at the first group of combustion air inlets, so that the oxygen content at the first group of combustion air inlets reaches a first oxygen content, which is, for example, 60% of the theoretical oxygen demand in the normal combustion process of the sulfur-containing waste, thereby the sulfur-containing waste is burned in an lean-oxygen environment, so that the generation of nitrogen oxides from the substances containing nitrogen element in the sulfur-containing waste, such as (N114)2504 and/or N114}1SO4, is inhibited during the reaction.
Step S13: controlling the air to enter into the second group of combustion air inlets, so that the oxygen content at the second group of combustion air inlets is a second oxygen content, which is the theoretical oxygen demand in the normal combustion process of the sulfur-containing waste, wherein the first oxygen content is smaller than the second oxygen content.
For example, in order to complete the normal combustion process, air is supplemented at the second group of combustion air inlets at the terminal of the reactor, so that the oxygen content at the second group of combustion air inlets reaches a second oxygen content, which, for example, is the theoretical oxygen demand in the normal combustion process of the sulfur-containing waste; thus, the normal combustion process of the sulfur-containing waste can be completed. Owing to the fact that the amount of generated nitrogen oxides is related with the temperature, i.e., increases as the temperature rises, the amount of nitrogen oxides generated at the terminal of the reactor away from the flame cone will also be reduced even though the oxygen content is adequate if the temperature is relatively low there.
With the method described above, since nitrogen oxides are reduced, the content of sulfur dioxide in the process gas in the reactor can be increased; in addition, since the expected combustion process is completed, there is no adverse effect on the normal process.
Fig. 6 is a flow chart of the method for reactor combustion control of the sulfur-containing waste treatment system in another embodiment of the present disclosure. In this embodiment,

9 Date recue/Date received 2023-04-20 the reactor body further comprises a third combustion air inlet arranged in the middle of the reactor body, and the method comprises:
Step S21: detecting the oxygen content at the first group of combustion air inlets and the second group of combustion air inlets;
Step S22: controlling the air to enter into the first group of combustion air inlets, so that the oxygen content at the first group of combustion air inlets is a first oxygen content;
For example, the embodiment of steps S21-22 is similar to the above embodiment of steps Sll-12, and will not be described further here.
Step S23: controlling the air to enter into the third group of combustion air inlets, so that the oxygen content at the third group of combustion air inlets is a third oxygen content. The third oxygen content may be, for example, 95% of the second oxygen content. The sulfur-containing waste is still burned in a lean-oxygen environment, so that the generation of nitrogen oxides from the substances containing nitrogen element in the sulfur-containing waste, such as (N114)2504 and/or N}14}1SO4, is inhibited.
Step S24: controlling the air to enter into the second group of combustion air inlets, so that the oxygen content at the second group of combustion air inlets is a second oxygen content, which is the theoretical oxygen demand in the normal combustion process of the sulfur-containing waste, wherein the first oxygen content is smaller than the second oxygen content, and the third oxygen content is smaller than the second oxygen content.
For example, similarly, in order to complete the normal combustion process, air is supplemented at the second group of combustion air inlets at the terminal of the reactor, so that the oxygen content at the second group of combustion air inlets reaches a second oxygen content, thereby the normal combustion process of the sulfur-containing waste can be completed.
It can be understood that although an embodiment having two group of combustion air inlets and an embodiment having three group of combustion air inlets are described above, it is also possible that the reactor have more air inlets; for example, the reactor may have a plurality of third groups of combustion air inlets, and these air inlets are used to supply air at the same time, as long as the oxygen content at the air inlets at the terminal of the reactor meets the theoretical Date recue/Date received 2023-04-20 oxygen demand in the normal combustion process of the sulfur-containing waste, while the oxygen contents at the other air inlets are lower than the theoretical oxygen demand in the normal combustion process of the sulfur-containing waste. The specific arrangement of the air inlets will not be further detailed here.
In the above process, the fuel and the sulfur-containing waste to be burned are controlled to have combustion for two times, including a first combustion corresponding to the first oxygen content and a second combustion corresponding to the second oxygen content, and finally a gas containing sulfur dioxide is obtained.
The first combustion has an oxygen coefficient X1 and a temperature of 1,100-1,250 C; the last combustion has an oxygen coefficient X3 and a temperature of 1,000-1,100 C;
the optional remaining combustions has an oxygen coefficient X2 and a temperature of 1,100-1,200 C
respectively and independently, and 0.5<X1<0.85, 0.7<X1+X2<1, 1<X1+X2+X3<1.15.
The oxygen coefficient refers to a ratio of the molar volume of the oxygen-containing combustion gas measured in the oxygen contained in the oxygen-containing combustion gas to the molar volume of oxygen required for complete combustion of the fuel.
In the present disclosure, the oxygen coefficient refers to a ratio of the molar volume of the oxygen-containing combustion gas measured in the oxygen contained in the oxygen-containing combustion gas to the molar volume of oxygen required for complete combustion of the fuel in each combustion process. Here, the fuel refers to the initial total fuel rather than the remaining fuel after the previous combustion.
According to the present disclosure, by controlling the volume of the oxygen-containing combustion gas used in each combustion process, the oxygen coefficient in each combustion process can be adjusted. By controlling the oxygen coefficient in combination with other process conditions, e.g., temperature, in each combustion process, normal combustion of the sulfur-containing waste can be realized, and a process gas with high sulfur dioxide content can be obtained.
In addition, especially for reaction materials containing nitrogen element, with the method provided by the present disclosure, the content of nitrogen oxides (NO) in the process gas can Date recue/Date received 2023-04-20 be decreased significantly, without additional denitration treatment.
Therefore, the method is environment-friendly and cost-efficient.
Preferably, in the first combustion, the oxygen coefficient is Xl, and the temperature is 1,150-1,250 C; in the last combustion, the oxygen coefficient is X3, and the temperature is 1,050-1,100 C; in the optional remaining combustions, the oxygen coefficient is X2 respectively and independently, the temperature is 1,100-1,200 C respectively and independently, and 0.7<X1<0.85, 0.8<X1+X2<1, and 1<X1+X2+X3<1.15. Thus, the inventor of the present disclosure has found: by particularly controlling the oxygen coefficient and the temperature in each combustion reaction process to be within the above-mentioned ranges in combination, the sulfur-containing waste will be burned more fully, the content of sulfur dioxide in the resulting process gas containing sulfur dioxide will be higher; especially, for reaction materials containing nitrogen element, the content of NO in the resulting process gas will be lower.
According to the present disclosure, the at least two times of combustion means that the combustion can be carried out for more than two times (e.g., three times, four times, or five times, etc.). That is to say, the optional existence means that the remaining combustion processes may exist or don't exist.
Preferably, the combustion is carried out for 2-3 times.
According to the present disclosure, it should be noted: when there are two times of combustion, only the first combustion and the last combustion exist, without any remaining combustion process.
According to a preferred embodiment of the present disclosure, the combustion is carried out for two times, and the method comprises:
In the present of the oxygen-containing combustion gas, controlling the fuel and the sulfur-containing waste to be burned to have a first combustion and a second combustion, to obtain a gas containing sulfur dioxide.
Preferably, the conditions of the first combustion include: the oxygen coefficient is X1 , and the temperature is 1,150-1,250 C; the conditions of the second combustion include:
the oxygen coefficient is X3, and the temperature is 1,050-1,100 C; and 0.7<X1<0.85, and l<X1+X3<1.15.

Date recue/Date received 2023-04-20 According to another preferred embodiment of the present disclosure, the combustion is carried out for three times, and the method comprises:
In the present of the oxygen-containing combustion gas, controlling the fuel and the sulfur-containing waste to be burned to have a first combustion, a second combustion, and a third combustion, to obtain a gas containing sulfur dioxide.
Preferably, the conditions of the first combustion include: the oxygen coefficient is X1 , and the temperature is 1,150-1,250 C; the conditions of the second combustion include:
the oxygen coefficient is X2, and the temperature is 1,100-1,200 C; the conditions of the third combustion include: the oxygen coefficient is X3, and the temperature is 1,050-1,100 C;
and 0.7<X1<0.85, 0 .8<X1+X2<1, and 1<X1+X2+X3<1.15.
Preferably, the oxygen-containing combustion gas is selected from at least one of air (containing 21 mol% oxygen), oxygen-enriched air (containing 21-40 mol% oxygen), pure oxygen and liquid oxygen. The inventor of the present disclosure has found: by using oxygen-enriched air or pure oxygen gas as the combustion gas, the fuel consumption can be reduced greatly, and more sulfur-containing waste can be treated in a device at an equivalent scale, thus the equipment investment can be reduced, and the energy consumption and the operating cost can be reduced.
Preferably, the sulfur-containing waste is selected from at least one of waste sulfuric acid, sulfur-containing waste liquor, and sulfur-containing waste gas.
There is no particular restriction on the source and kind of the sulfur-containing waste in the present disclosure. For example, the sulfur-containing waste liquor may be liquid sulfur, sulfur-containing waste liquor containing ammonium sulfate, sulfur-containing waste liquor containing ammonium hydrogen sulfate, sulfur-containing waste liquor containing ferric sulfate, sulfur-containing waste liquor containing methyl sulfate, or sulfur-containing waste liquor containing gypsum, etc.; the sulfur-containing waste gas may be hydrogen sulfide, sulfur dioxide, or other sulfur-containing waste gas, etc., for example; preferably, the mass concentration of sulfuric acid in the waste sulfuric acid is 50-99%.
Preferably, the water content of the sulfur-containing waste is less than 15 wt%.

Date recue/Date received 2023-04-20 According to a preferred embodiment of the present disclosure, the reactor assembly further comprises a fluid sprayer 116, which is configured to fully atomize the sulfur-containing waste (e.g., sulfur-containing waste liquor). Thus, the sulfur-containing waste is atomized under the high-pressure atomizing air flow from the fluid sprayer and then sprayed into the hearth for combustion with the oxygen-containing combustion gas and the fuel, thereby the combustion of the sulfur-containing waste is more intensive and the content of sulfur dioxide in the process gas is improved. Preferably, the pressure of the fluid sprayer is 0.4-0.8 MPa, more preferably is 0.5-0.7 MPa.
According to a preferred embodiment of the present disclosure, the sulfur-containing waste contains sulfur-containing solid waste (e.g., sulfur-containing ore), and the method in the present disclosure comprises: controlling the sulfur-containing solid waste to have combustion (the combustion conditions include: 800-1,050 C temperature) for one time, to obtain a gas containing sulfur dioxide II; controlling the sulfur-containing waste liquor and/or the sulfur-containing waste gas to have combustion for at least two times, to obtain a gas containing sulfur dioxide I; and merging the gas containing sulfur dioxide II with the gas containing sulfur dioxide Ito obtain the gas containing sulfur dioxide in the present disclosure.
According to the present disclosure, the fuel is a high-heat combustible material that can combust to provide heat for the combustion of the sulfur-containing waste.
Preferably, the heat value of the fuel is higher than or equal to 500 kcal/Nm3; for example, the heat value of natural gas is 9,700 kcal/Nm3.
Preferably, the fuel is selected from at least one of natural gas, sulfur, liquefied hydrocarbons, hydrogen sulfide sour gas, and heavy oil organic substances.
Preferably, the liquefied hydrocarbons are selected from at least one of liquefied ethylene, liquefied ethane, liquefied propylene, liquefied propane, liquefied butene and liquefied butane.
Preferably, the heavy oil organic substances are selected from at least one of gasoline, kerosene and diesel oil.
According to the present disclosure, the consumption of the fuel may be selected and adjusted according to the amount of the sulfur-containing waste.

Date recue/Date received 2023-04-20 According to the present disclosure, it should be noted specially that the sulfur-containing waste and the fuel may be the same substance (e.g., both of them may be hydrogen sulfide). Those skilled in the art should appreciate: in the case that the sulfur-containing waste is hydrogen sulfide sour gas, the hydrogen sulfide sour gas itself may be used as the fuel, without the need for any other additional fuel. Such a case still belongs to the inventive concept of the present disclosure and should not be understood by those skilled in the art as constituting any limitation to the present disclosure.
Preferably, with the method for burning sulfur-containing waste in the present disclosure, in the resulting gas containing sulfur dioxide, the content of sulfur dioxide is 3-12 mol%; the content of NO is lower than or equal to 100 mg/m3, and the content of oxygen is 0.5-5 mol%.
In the present disclosure, by controlling the conditions of each combustion reaction process, especially by controlling the temperature and the oxygen coefficient, the first combustion reaction process of the fuel and the sulfur-containing waste to be burned is carried out under the conditions of high temperature and lean oxygen, thereby the sulfur-containing waste can be burned to generate sulfur dioxide, while the nitrogen-containing material generates nitrogen under the lean oxygen condition; the subsequent combustion is carried out under the conditions of lower temperature and rich oxygen, thereby the normal combustion of the fuel and the sulfur-containing waste is ensured, while the nitrogen generated in the previous combustion can't react further to generate nitrogen oxides. Thus, through coordinated combustion reaction processes, a process gas with higher sulfur dioxide content and lower NO content is obtained, and the obtained gas containing sulfur dioxide doesn't contain any combustible component.
According to the present disclosure, preferably, at least one of the oxygen-containing combustion gas, the fuel and the sulfur-containing waste contains nitrogen element; wherein, the sulfur-containing waste is a nitrogen-containing and sulfur-containing substance, such as ammonium hydrogen sulfate and ammonium sulfate, etc., for example; the fuel is a combustible material containing nitrogen, for example; the oxygen-containing combustion gas is air, for example.
According to a preferred embodiment of the present disclosure, the method in the present disclosure further comprises: treating the sulfur-containing waste by water removal first, and Date recue/Date received 2023-04-20 then controlling the sulfur-containing waste and the fuel to have combustion for at least two times in the presence of the oxygen-containing combustion gas to obtain a gas containing sulfur dioxide.
There is no particular restriction on the specific operation of the water removal treatment, as long as the water in the sulfur-containing waste is removed at least partially in the water removal treatment. For example, the water removal treatment may be carried out by evaporation and concentration.
In the method provided by the present disclosure, the combustion conditions of the sulfur-containing waste are controlled especially, and the combustion reaction processes are coordinated, thereby the combustion of the sulfur-containing waste is more complete, a process gas with higher sulfur dioxide content is obtained, and the obtained gas containing sulfur dioxide doesn't contain any combustible component.
Particularly, for nitrogen-containing reaction materials, by particularly controlling the conditions of each combustion process with the method provided by the present disclosure, a process gas with higher sulfur dioxide content and lower NO content is obtained, and almost all nitrogen content in the nitrogen-containing reaction materials is emitted in the form of nitrogen gas, except for trace NOR. With the method provided by the present disclosure, the content of nitrogen oxides (NOR) in the resulting process gas can be reduced significantly, without any additional denitration treatment.
On that basis, the present disclosure further provides a method for making sulfuric acid from sulfur-containing waste, which comprises the following steps:
(1) burning the sulfur-containing waste to obtain a gas containing sulfur dioxide;
(2) oxidizing the gas containing sulfur dioxide to obtain a gas containing sulfur trioxide;
(3) absorbing the gas containing sulfur trioxide to obtain sulfuric acid.
Hereunder the present disclosure will be detailed in examples.
Unless otherwise specified, all the raw materials used in the following examples are commercially available.

Date recue/Date received 2023-04-20 Unless otherwise specified, the following examples were carried out in the aforementioned reactor assembly. In the reactor assembly, two groups of combustion gas inlets are distributed in the axial direction of the reactor (in the axial direction of the reactor, the axial length of a straight cylindrical section of the hearth is L, and the length-diameter ratio is 4-10 (e.g., the length-diameter ratio is 5), and two combustion gas inlets are arranged at 0.25L from the fuel inlet end of the hearth and 0.5L from the gas outlet end of the hearth respectively), so as to supply oxygen-containing combustion gas required for the combustion process, and the oxygen-containing combustion gas inlets are configured to supply oxygen-containing combustion gas flowing in the tangential direction of the inner wall of the hearth into the hearth.
Example lA
The specific compositions of the fuel used in this example and the sulfur-containing waste from the chemical fiber industry are shown in table 1, and the oxygen-containing combustion gas is air with 21 mol% oxygen content.
Table 1 Component Waste sulfuric acid Sulfur-containing Natural gas /wt%
/wt% waste liquor /wt%
H2SO4 16.8 H20 30.2 48.4 (NH4) 2SO4 39.5 N11411SO4 52.2 Polymer (organic 10.2 substance) Acrylic acid 1.9 Others (methanol, 0.8 MMA) CH4 96.3 C2H6 2.58 Cl-05 0.72 N2 0.4 The reactor was heated up to 1,200 C, the natural air is pressurized by an air blower then heated up to 630 C in an electric heating furnace, and entered the reactor through the combustion gas inlets; the sulfur-containing waste was sprayed into the hearth of the reactor from the sulfur-containing waste inlet by a fluid sprayer in 0.6 MPa high-pressure atomizing air; and the fuel Date recue/Date received 2023-04-20 was introduced into the hearth from the fuel inlet.
The process was as follows:
38.11t sulfur-containing waste (68.22 wt% waste sulfuric acid + 31.78 wt%
sulfur-containing waste liquor) and 3990 kg fuel were introduced into the reactor through the sulfur-containing waste inlet and the fuel inlet respectively, and were moved in the axial direction of the hearth to have a first combustion with the oxygen-containing combustion gas introduced from the first oxygen-containing combustion gas inlet, and then have a second combustion with the oxygen-containing combustion gas introduced from the second oxygen-containing combustion gas inlet;
wherein the conditions of the first combustion included: the oxygen coefficient was X1=0.7, and the temperature was 1,200 C; the conditions of the second combustion included: the oxygen coefficient was X3, X1+X3=1.05, and the temperature was 1,100 C; thus a gas containing sulfur dioxide was obtained;
In the gas containing sulfur dioxide discharged from the reactor, the content of sulfur dioxide was 3.8 mol%, the content of oxygen was 2 mol%, the content of NO was lower than or equal to 100 mg/Nm3, and the conversion ratio of sulfur dioxide was 99 mol%.
Example 1B
The method was essentially the same as that in the Example 1A, except that the oxygen-containing combustion gas was oxygen-enriched air with 40 mol% oxygen content, and other methods were the same as in Example 1.
In the gas containing sulfur dioxide discharged from the reactor, the content of oxygen was 2 mol%, the content of sulfur dioxide was 6 mol%, the content of NO was lower than or equal to 80 mg/Nm3, and the conversion ratio of sulfur dioxide was 99 mol%.
Example 2 The specific compositions of the chlorine-containing waste sulfuric acid, hydrogen sulfide sour gas and fuel used in this example are shown in table 2, and the oxygen-containing combustion Date recue/Date received 2023-04-20 gas is air with 21 mol% oxygen content.
Table 2 Chlorine-Waste gas containing Mass fraction containing waste Natural gas /wt%
hydrogen sulfide /wt%
sulfuric acid /wt%

Polymer (organic substance) H2S 94.98 H20 4.45 CO2 0.47 0.3 Cl-C3 0.1 3 CH4 93.5 N2 3.2 The reactor was heated up to 1,100 C, and natural air was blasted by an air blaster into the reactor through the combustion gas inlet. The sulfur-containing waste was sprayed into the hearth of the reactor from the sulfur-containing waste inlet by a fluid sprayer in 0.7 MPa high-pressure atomizing air; and the fuel was introduced into the hearth from the fuel inlet.
In this example, 7t sulfur-containing waste (71.43 wt% chlorine-containing waste sulfuric acid + 28.57 wt% hydrogen sulfide sour gas) was treated, wherein the chlorine-containing waste sulfuric acid produced by a polytetrahydrofuran production unit had 48 wt%
water content and less impurities, and was concentrated to 85 wt% by evaporation before it was introduced into the reactor 9; although the hydrogen sulfide sour gas was sulfur-containing waste gas, it only provided 70 mol% heat for the reactor system, while the lacking 30 mol% heat is replenished by natural gas auxiliary fuel.
The specific reaction process was as follows:
The waste sulfuric acid was introduced into the hearth of the reactor through the sulfur-containing waste inlet, the hydrogen sulfide sour gas and natural gas were introduced into the hearth of the reactor through the fuel inlet; the mixture was moved in the axial direction of the hearth to have a first combustion with the oxygen-containing combustion gas introduced through the first oxygen-containing combustion gas inlet, and then have a second combustion Date recue/Date received 2023-04-20 with the oxygen-containing combustion gas introduced through the second oxygen-containing combustion gas inlet; wherein the conditions of the first combustion included:
the oxygen coefficient was X1=0.75, and the temperature was 1,150 C; the conditions of the second combustion included: the oxygen coefficient was X3, Xl+X3=1.05, and the temperature was 1,050 C; thus a gas containing sulfur dioxide was obtained;
In the gas containing sulfur dioxide discharged from the reactor, the content of oxygen was 3 mol%, the content of sulfur dioxide was 8.5 mol%, the content of NO was lower than or equal to 100 mg/Nm3, and the conversion ratio of sulfur dioxide 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 gas is air with 21 mol%
oxygen content.
Table 3 Sulfur-containing ore Waste sulfuric acid Mass fraction /wt% Liquefied gas /wt%
/wt%

H20 22.723 10 Polymer (organic substance) S 29.5 Fe 47.75 As 0.002 F 0.025 C4Hio 50 The reactor was heated up to 1,250 C, the natural air is pressurized by an air blower then heated up to 450 C in an electric heating furnace, and entered the reactor; the sulfur-containing waste was sprayed into the hearth of the reactor from the sulfur-containing waste inlet by a fluid Date recue/Date received 2023-04-20 sprayer in 0.5 MPa high-pressure atomizing air; and the fuel was introduced into the hearth from the fuel inlet.
The specific reaction process was as follows:
The waste sulfuric acid in 7.5t sulfur-containing waste (80 wt% waste sulfuric acid + 20 wt%
.. sulfur-containing ore) and 120 kg fuel were introduced into the hearth of the reactor through the sulfur-containing waste inlet and the fuel inlet respectively, and were moved in the axial direction of the hearth to have a first combustion with the oxygen-containing combustion gas introduced from the first oxygen-containing combustion gas inlet, and then have a second combustion with the oxygen-containing combustion gas introduced from the second oxygen-containing combustion gas inlet; wherein the conditions of the first combustion included: the oxygen coefficient was X1=0.85, and the temperature was 1,200 C; the conditions of the second combustion included: the oxygen coefficient was X3, Xl+X3=1.05, and the temperature was 1,050 C; thus a gas containing sulfur dioxide I was obtained; the sulfur-containing ore was burned in another reactor (at 800 C temperature) to generate a process gas containing sulfur dioxide II;
In the sulfur dioxide gas mixture discharged from the two reactors, the content of oxygen was 5 mol%, the content of sulfur dioxide was 6 mol%, the content of NO was lower than or equal to 100 mg/Nm3, and the conversion ratio of sulfur dioxide was 99 mol%.
Comparative Example 1 The method was similar to that in the Example 1, except that the combustion was carried out only for one time.
The specific process was as follows: 38.11t sulfur-containing waste (68.22 wt%
waste sulfuric acid + 31.78 wt% sulfur-containing waste liquor) and 4,588 kg fuel were introduced into the hearth of the reactor through the material inlet, and were moved in the axial direction of the hearth to have combustion with the oxygen-containing combustion gas introduced through the first oxygen-containing combustion gas inlet, wherein the conditions of the combustion included: the oxygen coefficient was 1.04, the temperature was 1,150 C; thus, a gas containing Date recue/Date received 2023-04-20 sulfur dioxide was obtained;
The temperature of the gas containing sulfur dioxide discharged from the reactor was 950-1,000 C, the content of oxygen in the gas containing sulfur dioxide was 1.8 mol%, the content of sulfur dioxide was 3.2 mol%, the content of NO was about 500 mg/Nm3, and the conversion ratio of sulfur dioxide was 98.8 mol%. The fuel consumption in the comparative example was higher than that in the Example 1 by 15 wt%.
Comparative Example 2 The method was similar to that in the Example 1, except that the oxygen coefficients in the two combustion cracking processes were different from the oxygen coefficient in the Example 1.
Specifically, the oxygen coefficient X1 in the first combustion process was 0.9, and the oxygen coefficient in the second combustion process was X3, and X1+X3=1.05;
All other conditions were the same as those in the Example 1. In that way, a gas containing sulfur dioxide was obtained; in the gas containing sulfur dioxide discharged from the reactor, .. the content of oxygen was 2 mol%, and the content of NO was about 200 mg/Nm3.
Furthermore, as shown in Figs. 1 and 4, the combustion air supply mechanism may further comprise a heating device 120 and a blower fan 130. The heating device has a heating shell 121, which has a heating chamber 123 therein and an electric heating mechanism 122 arranged in the heating chamber 123. The heating shell 121 is provided with a heating gas inlet 124 and a heating gas outlet 125 that are in communication with the heating chamber 123 respectively, the heating gas inlet 124 is in communication with the blower fan 130, and the heating gas outlet 125 is in communication with the hearth 111 of the reactor assembly;
the electric heating mechanism 122 is configured to be able to raise the temperature inside the heating chamber 123.
Since the heating gas inlet 124 is in communication with the blower fan 130 and the heating gas outlet 125 is in communication with the hearth 111 of the reactor assembly, the electric heating mechanism 122 can raise the temperature inside the heating chamber 123. Therefore, the temperature of the combustion air blasted by the blower fan 130 can be raised when the Date recue/Date received 2023-04-20 combustion air passes through the heating device 120, thus the temperature of the combustion air entering the hearth 111 can be as high as 600-650 C, thereby the combustion efficiency of the gas mixture in the reactor assembly is improved.
As shown in Figs. 7 and 8, the present disclosure further provides a sulfur-containing waste treatment system, which comprises:
the aforesaid reactor assembly 100, which is configured to enable the sulfur-containing waste to perform a combustion reaction to obtain a first gas containing sulfur dioxide;
a heat recovery unit 300 configured to recover heat from the first gas to obtain a second gas;
a purifying and cooling unit configured to purify and cool down the second gas to obtain a third gas;
a drying unit 700 configured to dry the third gas to obtain a fourth gas; and an oxidation and absorption unit 800 configured to oxidize and absorb the fourth gas to obtain sulfuric acid and exhaust gas.
The specific operating process of the treatment system will be described in the following examples:
Although the water content of the sulfur-containing waste is 36 wt% in waste sulfuric acid and sulfur-containing waste liquor (68.22 wt% waste sulfuric acid + 31.78 wt%
sulfur-containing waste liquor), it is difficult to thicken the waste sulfuric acid and the sulfur-containing waste liquor in the chemical fiber industry by dehydration owing to the fact that the waste sulfuric acid and the sulfur-containing waste liquor contain a lot of particles and impurities. Therefore, the waste sulfuric acid and the sulfur-containing waste liquor are directly fed into the reactor body 110 without dehydration.
(1) the sulfur-containing waste is atomized and sprayed into the reactor body 110 by a fluid sprayer under 0.6 MPa high pressure, the reaction temperature in the hearth is 1,200 C, and the fuel (natural gas) provides heat; air within 21 mol% oxygen content is used for supporting combustion, combustion air at normal temperature is pressurized by a blower fan 130 and then heated up to 630 C in a heating device 120, and the high-temperature Date recue/Date received 2023-04-20 combustion air is introduced into the hearth through different combustion gas inlets 114 and 115. The sulfur-containing waste has a first combustion with the combustion gas introduced through the first group of combustion air inlets 114a and 115a, then has a second combustion with the combustion gas introduced through the second group of combustion air inlets 114b and 115b; wherein the conditions of the first combustion include: the oxygen coefficient is X1=0.7, and the temperature is 1,200 C; the conditions of the second combustion include: the oxygen coefficient is X3, Xl+X3=1.05, and the temperature is 1,100 C, the remaining oxygen content in the first gas discharged from the hearth is 2 mol%, and the residence time of the process gas in the hearth is greater than or equal to 5 seconds;
(2) The metal dust in the high-temperature process gas discharged from the hearth is removed in the dust removal unit 200 to obtain dedusted high-temperature process gas (the operating conditions of the cyclone dust collector 210 include: the inlet temperature is 1,100 C, the inlet pressure is -1 kPa, and the air speed at the inlet of the cyclone dust collector is 30 m/s; the conditions of the dust removal operation of the ceramic membrane filter 220 include: the inlet temperature is 1,050 C, the inlet pressure is -1 kPa, and the air speed at the inlet of the ceramic membrane filter is 15m/s); then the hot process gas enters the waste heat boiler 310 for heat recovery (the first heat exchange, the conditions include:
the pressure at the tube flue gas side is -1.5 kPa, the temperature at the flue gas inlet of the boiler is 1,000 C, and the temperature at the flue gas outlet of the boiler is 380 C; the pressure at the shell steam side is 3.8 MPa, and the temperature is 249 C), 3 it saturated steam at 3.8 MPa is produced per hour. The saturated steam exchanges heat with a small fraction of the solid-free hot process gas in the steam superheater 320 (the second heat exchange, the conditions include: the pressure at the flue gas side is -1.5 kPa, the temperature at the flue gas inlet of the superheater is 1,000 C, and the temperature at the flue gas outlet of the superheater is 450 C; the pressure at the steam side is 3.8 MPa, and the temperature is 350 C), hot steam 16 is obtained, and the super-heated steam enters the steam turbine to reduce the power consumption of the device;
(3) After the heat recovery, the process gas enters the quenching and humidifying column 400 for quenching by adiabatic humidification, and the gas temperature drops steeply from Date recue/Date received 2023-04-20 400 C to 77 C. Then the process gas enters the multi-stage filled cooling and absorption column 500; first, the process gas enters the first absorption layer and washed and cooled by a circulating water cooler to 35 C, then the process gas enters a second absorption layer and washed and cooled by a chilled water cooler to 29 C; after the twice cooling, the process gas enters the electrostatic mist precipitator 600 to remove the acid mist of sulfur trioxide;
(4) After the acid mist of sulfur trioxide is removed, the process gas enters the drying unit 700 and dried by 93 wt% concentrated sulfuric acid;
(5) The sulfur dioxide content in the dried process gas is 5 mol%, the process gas is boosted to 20 kPa by a main blower 810 and then enters a first external heat exchanger 830 and a second heat exchange pipeline 845b (see Fig. 13) for heat exchange, then the process gas 37 has an oxidation reaction in the first catalyst layer 844a in a converter 840 at 415 5 C
temperature. After the reaction, the process gas reaches 555 5 C temperature, then exchanges heat with the tube side gas in the first heat exchange pipeline 845a of the converter 840, thereby the process gas in the second catalyst layer 844b reaches 455 5 C
temperature and has an oxidation reaction; the first oxidation reaction is completed in the first conversion chamber, and the conversion ratio of the first oxidation reaction is 96 mol%; after the first oxidation reaction, the process gas 38 exchanges heat with the tube side gas in the first external heat exchanger 830 and the temperature of the process gas is controlled to be higher than or equal to 150 C; then the process gas enters the first absorption layer of the multi-stage absorption column 880 for first absorption with 100 wt%
sulfuric acid, and the absorption ratio is 99.99 wt%;
After the first absorption, the process gas enters the second external heat exchanger 870 and the first heat exchange pipeline 845a sequentially for heat exchange, and then enters the second conversion chamber. The process gas in the third catalyst layer 844c reaches temperature and starts an oxidation reaction; after the oxidation reaction, the process gas containing sulfur trioxide exchanges heat in the second heat exchange pipeline 845b, then has an oxidation reaction in the fourth catalyst layer 844d at 415 5 C
temperature, the second oxidation reaction is completed in the second conversion chamber, the total conversion ratio of Date recue/Date received 2023-04-20 the process gas in the four catalyst layers after the reaction is 99.92 mol%;
then the temperature of the process gas exiting the second conversion gas outlet after the second oxidation reaction is controlled to be higher than or equal to 130 C, and the process gas enters the second absorption layer of the multi-stage absorption column 880 for second absorption with 98 wt%
sulfuric acid, and the absorption ratio is 99.99 wt%.
After the second absorption, the process gas is exhausted. In the exhaust gas, the SO2 concentration is lower than or equal to 50 mg/Nm3, the NO concentration is lower than or equal to 50 mg/Nm3, the acid mist concentration is lower than or equal to 5 mg/Nm3, and the particle concentration is lower than or equal to 30 mg/Nm3.
Fig. 9 shows the connection structure of the dust removal unit 200 and the heat recovery unit 300 in the above sulfur-containing waste treatment system, wherein the heat recovery unit 300 is connected downstream of the dust removal unit 200. The dust removal unit 200 includes at least two filter groups arranged in parallel, and each filter group includes two filters, namely a cyclone dust collector 210 and a ceramic membrane filter 220, and the ceramic membrane filter 220 is connected in series downstream of the cyclone dust collector 210; the shell of the cyclone dust collector 210 is made of high-alloy steel; the inner wall of the cyclone dust collector 210 is provided with a heat insulation layer and a fire resistance layer sequentially, and the heat insulation layer is made of a light-weight cast material and/or light-weight refractory bricks;
the fire resistance layer is made of at least one of corundum bricks, corundum mullite bricks, chrome corundum bricks and silicon carbide; the air inlet of the cyclone dust collector has a spiral surface structure; the ash outlet of the cyclone dust collector employs a star-shaped ash valve structure or overflow spiral structure. The heat recovery unit 300 includes a waste heat boiler 310 and a steam superheater 320, both of which are in communication with the dust removal unit 200, and the waste heat boiler 310 and the steam superheater 320 are in communication with each other, so that the saturated steam obtained from the waste heat boiler 310 can enter the steam superheater 320.
By using a combination of specific dust removal unit and heat recovery unit and arranging specific heat insulation layer and fire resistance layer on the inner wall of the cyclone dust collector, in conjunction with specific device structure and combination, the requirement of the Date recue/Date received 2023-04-20 high-temperature ash-laden flue gas (e.g., the flue gas containing sulfur dioxide at 900-1,200 C
temperature from the high-temperature cracking furnace in the high-temperature combustion cracking process of the sulfur-containing waste) for the equipment is met, high dust removal efficiency is achieved, and the heat loss of the ash-laden high-temperature flue gas in the dust removing device can be reduced significantly.
The purifying and cooling unit in the above sulfur-containing waste treatment system may comprise a quenching and humidifying column 400, a multi-stage cooling and absorption column 500 and an electrostatic mist precipitator 600 that are in communication with each other sequentially, and the quenching and humidifying column 400 is in communication with the heat recovery unit 300.
Fig. 10 is a schematic diagram of a quenching and humidifying column 400. The quenching and humidifying column 400 comprises a first column body 410 and a spraying assembly 420;
the first column body 410 comprises a cooling chamber 411, and a chamber inlet 412 and a chamber outlet 413 that are in communication with the outer wall of the first column body 410 and the cooling chamber 411, wherein the chamber inlet 412 is positioned in the lower part of the column body 410, and the chamber outlet 413 is positioned in the upper part of the column body 410; the spraying assembly 420 is arranged inside the cooling chamber 411 and comprises a first spraying port 420 and a second spraying port 421, wherein the first spraying port 422 is configured to be able to spray a cooling fluid downward, the second spraying port 421 is configured to be able to spray the cooling fluid upward, and the first spraying port 422 and the second spraying port 421 are arranged opposite to each other.
Since the first spraying port 421 of the spraying assembly 420 is configured to spray the cooling fluid downward and the second spraying port 422 is configured to spray the cooling fluid upward, and the first spraying port 421 and the second spraying port 422 are arranged opposite to each other, the cooling fluid sprayed from the first spraying port 421 and the second spraying port 422 can respectively cool the high-temperature process gas from above and below as the high-temperature process gas enters the cooling chamber 411 from the chamber inlet 412 and flows toward the chamber outlet 130, and the humidity of the high-temperature process gas is increased at the same time, so that the temperature of the high-temperature process gas can drop Date recue/Date received 2023-04-20 sharply from 320 C-350 C to 75 C-80 C, thereby the process gas is cooled rapidly and effectively, and the system resistance is lower, usually at 1 Kpa, thus the treatment period of the sulfur-containing wastes is shortened.
Furthermore, the quenching and humidifying column 400 may further comprise a unidirectional .. spray head 430, which is arranged between the spraying mechanism 420 and the chamber outlet 413 and configured to spray the cooling fluid downward, thereby the cooling effect is improved.
Fig. 11 is a schematic diagram of a cooling and absorption column 500. The cooling and absorption column comprises a second column body 510, a first absorption layer, and a second absorption layer; the second column body 510 is arranged in the vertical direction and has a cooling and absorption chamber extending in the vertical direction; the second column body 510 comprises a gas inlet and a gas outlet that are in communication with the cooling and absorption chamber respectively, wherein the gas inlet is arranged in the lower part of the second column body 510 and the gas outlet is arranged in the upper part of the second column body 510; the first absorption layer and the second absorption layer are arranged spaced apart .. from each other in the cooling and absorption chamber in the vertical direction, wherein the first absorption layer comprises a first spraying mechanism 520 capable of spraying an absorption fluid into the cooling and absorption chamber, and the second absorption layer comprises a second spraying mechanism 530 capable of spraying an absorption fluid into the cooling and absorption chamber.
.. Since the second column body 510 is arranged in the vertical direction and has a cooling and absorption chamber extending in the vertical direction, the footprint of the cooling and absorption column can be reduced, thereby the operation cost can be reduced.
In addition, since a first absorption layer and a second absorption layer are arranged spaced apart from each other in the vertical direction in the cooling and absorption chamber, the first absorption layer includes a first spraying mechanism 520 capable of spraying an absorption fluid into the cooling and absorption chamber, and the second absorption layer includes a second spraying mechanism 530 capable of spraying the absorption fluid into the cooling and absorption chamber, the process gas entering the cooling and absorption chamber from the gas inlet can have an absorption reaction with the absorption fluid sprayed by the first spraying mechanism 520 and Date recue/Date received 2023-04-20 the absorption fluid sprayed by the second spraying mechanism 530 respectively, and the absorption fluid can fully absorb the sulfur trioxide in the process gas, thus an effect of washing the process gas is attained.
Furthermore, the cooling and absorption chamber of the second column body 510 may be provided with a partition 513, which divides the cooling and absorption chamber into a first chamber and a second chamber from bottom to top, with the first absorption layer arranged in the first chamber and the second absorption layer arranged in the second chamber; the second column body 510 is provided with a gas inlet 511, a gas outlet 512, and an air vent in communication with the first chamber and the second chamber, wherein the gas inlet 511 is in communication with the first chamber and is positioned in the lower part of the first chamber for receiving external process gas; the gas outlet 512 is in communication with the second chamber and is positioned in the upper part of the second chamber for discharging the process gas to the downstream process. The first spraying mechanism 520 and the second spraying mechanism 530 are configured to be able to spray a refrigerating fluid that is at a temperature lower than the temperature of the cooling fluid while they spray the absorption fluid in the first chamber and the second chamber. An advantage of such an arrangement is that the temperature of the process gas can be further decreased by the refrigerating fluid; for example, the temperature of the cooling fluid is 28-32 C, the process gas is washed and cooled to about 35 C
after passing through the first absorption layer, and then the process gas can be washed and cooled to 15 C by the refrigerating fluid at 7-10 C temperature after passing through the second absorption layer, thus the cooling effect is greatly improved.
In order to improve the utilization efficiency of the cooling fluid, save energy and reduce the production cost, the cooling and absorption column 500 includes a water pump 560 and a cooler 570, thereby the absorption fluid and the refrigerating fluid are cooled and then circulated back .. to the cooling chamber.
To make the absorption fluid contact with the process gas more extensively, the first absorption layer may include a first filler 540, and the first spraying mechanism 520 is configured to spray the absorption fluid downward, and the first filler 540 is disposed below the first spraying mechanism 520; the second absorption layer may include a second filler 550, and the second Date recue/Date received 2023-04-20 spraying mechanism 530 is configured to spray the absorption fluid downward, and the second filler 550 is disposed below the second spraying mechanism 530. It should be understood that the fillers may be made of a variety of materials, as long as they can make the absorption fluid contact with the process gas more extensively. In an embodiment, the first filler 540 and the second filler 550 are polypropylene Heilex rings.
The process gas is purified, cooled, and dried by the drying unit 700, and then introduced into the oxidation and absorption unit 800 to convert the sulfur dioxide in the process gas into sulfur trioxide, which is absorbed to produce sulfuric acid. Fig. 12 is a schematic diagram of an oxidation and absorption unit 800, and Fig. 13 is a schematic structural diagram of a converter 840 in the oxidation and absorption unit 800.
The oxidation and absorption unit 800 comprises a conversion device and an absorption device, wherein the conversion device is kept in communication with the drying unit 700, and is configured to oxidize the sulfur dioxide in the fourth gas obtained in the drying unit 700 to obtain a gas containing sulfur trioxide; the absorption device is in communication with the conversion device and configured to carry out absorption treatment on the gas containing sulfur trioxide to obtain sulfuric acid and exhaust gas. Specifically, in the illustrated preferred embodiment, the oxidation and absorption unit 800 includes a first external heat exchanger 830, a second external heat exchanger 870, a multi-stage absorption column 880, a first heat exchanger 850, a second heat exchanger 860, a sulfuric acid cooler 890, an absorption circulating pump, and a converter 840 provided with a first heat exchange pipeline 845a and a second heat exchange pipeline 845b. The dotted line represents the heating pipeline, while the solid line represents the process pipeline, and the arrow indicates the flow direction of the medium during heating. The specific flow process is as follows: the process gas is blasted into a heating furnace 820 by the blower fan 810, then enters the first external heat exchanger 830, enters the converter 840, and then enters the second external heat exchanger 870, and finally returns to the blower fan 810 through the second heat exchanger 860, thus a cycle is completed.
In the heating process, the medium is circulated in the blower fan 810, the heating furnace 820 and the converter 840 and doesn't enter the multi-stage absorption column 880;
although the heating pipeline is overlapped with the process pipeline partially, it doesn't affect the normal process flow.
Date recue/Date received 2023-04-20 The converter 840 shown in Fig. 13 comprises a converter shell 841, a catalyst bed assembly and heat exchange pipelines 845a and 845b; the converter shell 841 has an conversion chamber therein, and is provided with conversion gas inlets 842a and 842b and conversion gas outlets 843a and 843b that are in communication with the conversion chamber; the catalyst bed assembly comprises at least two catalyst layers 844a, 844b, 844c, and 844d, which are arranged in the conversion chamber at an interval in the flow direction of the process gas; the heat exchange pipelines 845a and 845b match the catalyst layers 844a, 844b, 844c and 844d in quantity, and are arranged in the conversion chamber at least partially and disposed between adjacent catalyst layers. By arranging the heat exchange pipelines in the conversion chamber and between two adjacent catalyst layers, the occupied space can be greatly reduced and the operation cost can be effectively reduced.
Specifically, the converter 840 includes a first conversion chamber and a second conversion chamber, a first catalyst layer 844a, a second catalyst layer 844b, a third catalyst layer 844c, a fourth catalyst layer 844d, a first conversion gas inlet 842a, a second conversion gas inlet 842b, a first conversion gas outlet 843a and a second conversion gas outlet 843b formed in the converter shell 841; both the first conversion gas inlet 842a and the first conversion gas outlet 843a are in communication with the first conversion chamber so that the process gas can flow from the first conversion gas inlet 842a to the first conversion gas outlet 843a; both the second conversion gas inlet 842b and the second conversion gas outlet 843b are in communication with the second conversion chamber so that the process gas can flow from the second conversion gas inlet 842b to the second conversion gas outlet 843b; both the first catalyst layer 844a and the second catalyst layer 844b are arranged in the first conversion chamber and arranged at an interval in the flow direction of the process gas; both the third catalyst layer 844c and the fourth catalyst layer 844d are arranged in the second conversion chamber and arranged at an interval in the flow direction of the process gas.
In the present disclosure, the process gas enters the first conversion chamber through the first conversion gas inlet 842a, and the process gas reacts with the first catalyst layer 844a first, and then reacts with the second catalyst layer 844b. After the reaction, the process gas enters the external heat exchanger directly through the first conversion gas outlet 843a;
after the heat exchange in the external heat exchanger, the process gas containing sulfur trioxide reaches Date recue/Date received 2023-04-20 150 C or a higher temperature, and then the process gas enters the first stage of the multi-stage absorption column. The conversion ratio of the first conversion is 95%-96%, the absorption is carried out with 100 wt% sulfuric acid, and the absorption ratio is 99.99%.
After the absorption, the process gas enters the external heat exchanger for heat exchange; after the heat exchange, .. the process gas reaches 415 C-420 C temperature, and enters the second conversion chamber through the second conversion gas inlet 842b, the process gas may react with the third catalyst layer 844c first, and the process gas containing sulfur trioxide after the reaction exchanges heat in the second heat exchange pipeline 845b and then reacts with the fourth catalyst layer 844d;
after the reaction, temperature of the process gas is controlled at 130 C or a higher temperature, and the process gas enters the second stage of the multi-stage absorption column through the second conversion gas outlet 843b. The absorption ratio is 99.99%, and the process gas is exhausted after the absorption. In the exhaust gas, the concentration of SO2 is lower than or equal to 50mg/m3, the concentration of NO is lower than or equal to 100mg/m3, the concentration of acid mist is lower than or equal to 5mg/m3, and the concentration of particle substances is lower than or equal to 30mg/m3. Therefore, the converter in the present disclosure has the advantage of high conversion efficiency.
In order to arrange each catalyst layer more stably in the conversion chamber, in an embodiment of the present disclosure, the converter 840 includes a plurality of supporting assemblies corresponding to the first catalyst layer 844a, the second catalyst layer 844b, the third catalyst layer 844c and the fourth catalyst layer 844d in one-to-one correspondence.
Each supporting assembly includes a grating 846, and the edges of the grating 846 are connected to the inner wall of the converter shell 841 to provide support for the corresponding catalyst layer.
Furthermore, the supporting assembly includes a heat-resistant ceramic balls 847 arranged on the side of the catalyst layer opposite to the grating 846. In the present disclosure, the main function of the heat-resistant ceramic balls 847 is to press the catalyst layer to keep the catalyst layer lying on the grating 846, so as to prevent the catalyst layer from being blown away by the air flow. Besides, on one hand, the heat-resistant ceramic balls 847 can exchange heat with the passing process gas, so that the temperature of the process gas can drop to a temperature suitable for reacting with the catalyst layer; and on the other hand, the heat-resistant ceramic balls 847 can absorb foreign particles in the process gas and play a purifying role.

Date recue/Date received 2023-04-20 Based on the above-mentioned reactor assembly and sulfur-containing waste treatment system, the present disclosure further provides a method for burning sulfur-containing waste and a method for making sulfuric acid by regenerating sulfur-containing waste. The burned sulfur-containing waste may be waste sulfuric acid, sulfur-containing waste liquid and sulfur-containing waste gas, etc., and the fuel may be selected from at least one of natural gas, sulfur, liquefied hydrocarbons, hydrogen sulfides and heavy oil organic substances. In the process gas generated from combustion, the content of sulfur dioxide is 3-12 mol%, the content of NO is lower than or equal to 100 mg/m3, and the content of oxygen is 0.5-5 mol%.
While the present disclosure is described above in detail in some preferred embodiments with reference to the accompanying drawings, the present disclosure is not limited to those embodiments. Various simple variations may be made to the technical scheme of the present disclosure within the technical concept of the present disclosure. To avoid unnecessary repetition, various possible combinations are not described specifically in the present disclosure.
However, such simple variations and combinations shall also be deemed as having been disclosed and falling in the scope of protection of the present disclosure.

Date recue/Date received 2023-04-20

Claims

1. A reactor assembly, comprising a reactor body (110) having a hearth (111) for performing a combustion reaction of sulfur-containing waste and a fuel gas inlet (112) and a process gas outlet (113) that are in communication with the hearth (111), wherein the hearth (111) is of a cylindrical structure, the fuel gas inlet (112) and the process gas outlet (113) are arranged spaced apart from each other at two ends of the hearth (111) in an axial direction of the hearth (111), and the fuel gas inlet (112) is configured to be able to supply the hearth (111) with fuel flowing in the axial direction of the hearth (111);
the reactor assembly comprises a combustion air supply mechanism, which is configured to be able to supply the hearth (111) with combustion air flowing in a circumferential direction of an inner wall of the hearth (111).

2. The reactor assembly of claim 1, wherein the combustion air supply mechanism comprises a first combustion air inlet (141) and a second combustion air inlet (142) that are arranged on the reactor body (110) and in communication with the hearth (111) respectively, wherein the first combustion air inlet (114) and the second combustion air inlet (115) are configured to be able to supply combustion air to the hearth (111) in a tangent direction of the hearth (111) at different circumferential positions of the hearth (111), and the combustion air supplied via the first combustion air inlet (114) flows in the same direction as the combustion air supplied via the second combustion air inlet (115).

3. The reactor assembly of claim 1, wherein the combustion air supply mechanism comprises a plurality of groups of combustion air inlets that are arranged at intervals in the axial direction of the hearth (111).

4. The reactor assembly of claim 3, wherein the plurality of groups of combustion air inlets comprise a first group of combustion air inlets (114a, 115a) and a second group of combustion air inlets (114b, 115b), wherein the first group of combustion air inlets (114a, 115a) are arranged near the fuel gas inlet (112), and the second group of combustion air inlets (114b, 115b) are arranged near the process gas outlet (113);

Date recue/Date received 2023-04-20 the reactor assembly comprises a control device for controlling the combustion air supply mechanism, and the control device is configured to: control the air to enter via the first group of combustion air inlets (114a, 115a), so that the oxygen content at the first group of combustion air inlets (114a, 115a) is a first oxygen content; and control the air to enter via the second group of combustion air inlets (114b, 115b), so that the oxygen content at the second group of combustion air inlets (114b, 115b) is a second oxygen content, wherein the second oxygen content is equal to a theoretical oxygen demand of a nomial combustion process of the sulfur-containing waste, the first oxygen content is smaller than the second oxygen content, and the first oxygen content and the second oxygen content are controlled so that the fuel and the sulfur-containing waste to be burned have combustion for at least two times, including a first combustion corresponding to the first oxygen content and a second combustion corresponding to the second oxygen content.

5. The reactor assembly of claim 4, wherein the plurality of groups of combustion air inlets further comprise at least one third group of combustion air inlets arranged between the first group of combustion air inlets (114a, 115a) and the second group of combustion air inlets (114b, 115b); and the control device is further configured to: control the air to enter via the third group of combustion air inlets so that the oxygen content at the third group of combustion air inlets is smaller than the second oxygen content.

6. The reactor assembly of claim 4, wherein the first combustion has an oxygen coefficient X1 and a temperature of 1,100-1,250 C; the last combustion has an oxygen coefficient X3 and a temperature of 1,000-1,100 C; the optional remaining combustions have an oxygen coefficient X2 and a temperature of 1,100-1,200 C respectively and independently, and 0.5<X1<0.85, 0.7<X1+X2<1, and 1<X1+X2+X3<1.15;
the oxygen coefficient refers to a ratio of the volume of the oxygen-containing combustion gas measured in the molar content of oxygen to the molar content of oxygen required for complete combustion of the fuel.

7. The reactor assembly of claim 4, wherein the first oxygen content is 60% of the second Date recue/Date received 2023-04-20 oxygen content.

8. The reactor assembly of claim 1, wherein the combustion air supply mechanism comprises a heating device (120), which comprises a heating shell (121) and an electric heating mechanism (122);
the heating shell (121) is provided with a heating chamber (123) therein and a heating gas inlet (124) and a heating gas outlet (125) that are in communication with the heating chamber (123) respectively, wherein the heating gas inlet (124) is configured to be in communication with an external gas source, and the heating gas outlet (125) is in communication with the hearth (111) so as to be able to supply the combustion air to the hearth (111);
the electric heating mechanism (122) is configured to be able to raise the temperature inside the heating chamber (123).

9. A sulfur-containing waste treatment system, comprising:
the reactor assembly (100) of any of claims 1-8, which is configured to enable the sulfur-containing waste to perform a combustion reaction to obtain a first gas containing sulfur dioxide;
a heat recovery unit (300) configured to recover heat from the first gas to obtain a second gas;
a purifying and cooling unit configured to purify and cool down the second gas to obtain a third gas;
a drying unit (700) configured to dry the third gas to obtain a fourth gas;
and an oxidation and absorption unit (800) configured to oxidize and absorb the fourth gas to obtain sulfuric acid and exhaust gas.

10. The sulfur-containing waste treatment system of claim 9, comprising a dust removal unit (200) connected between the reactor assembly (100) and the heat recovery unit (300), wherein the first gas obtained in the reactor assembly (100) enters the dust removal unit (200) first for dust removal, and then enters the heat recovery unit (300) for heat recovery, Date recue/Date received 2023-04-20 so as to obtain the second gas.

11. The sulfur-containing waste treatment system of claim 10, wherein the dust removal unit (200) comprises at least two filter groups arranged in parallel connection, and each filter group includes at least one filter.

12. The sulfur-containing waste treatment system of claim 10, wherein the heat recovery unit (300) comprise a waste heat boiler (310) and a steam superheater (320), both of which are in communication with the dust removal unit (200), so that the process gas obtained in the dust removal unit (200) can enter the waste heat boiler (310) and the steam superheater (320) respectively; the waste heat boiler (310) and the steam superheater (320) are in communication with each other, so that saturated steam obtained in the waste heat boiler (310) can enter the steam superheater (320).

13. The sulfur-containing waste treatment system of claim 9, wherein the purifying and cooling unit comprises a quenching and humidifying column (400), a multi-stage cooling and absorption column (500), and an electrostatic mist precipitator (600) that are in communication with one after another, wherein the quenching and humidifying column (400) is in communication with the heat recovery unit (300).

14. The sulfur-containing waste treatment system of claim 13, wherein the quenching and humidifying column (400) comprises a first column body (410) and a spraying assembly (420);
the first column body (410) comprises a cooling chamber (411), and a chamber inlet (412) and a chamber outlet (413) that are arranged in an outer wall of the first column body (410) and in communication with the cooling chamber (411) respectively, wherein the chamber inlet (412) is disposed in a lower part of the first column body (410) and configured to receive the process gas from the process gas outlet (113) of the reactor assembly (100), and the chamber outlet (413) is disposed in an upper part of the first column body (410);
the spraying assembly (420) is arranged inside the cooling chamber (411) and comprises a first spraying port (421) and a second spraying port (422), wherein the first spraying port (421) is configured to be able to spray a cooling fluid downward, the second spraying port Date recue/Date received 2023-04-20 (422) is configured to be able to spray the cooling fluid upward, and the first spraying port (421) and the second spraying port (422) are arranged opposite to each other.

15. The sulfur-containing waste treatment system according to claim 13, wherein the cooling and absorption column (500) comprises a second column body (510), a first absorption layer, and a second absorption layer;
the second column body (510) is arranged in a vertical direction and comprises a cooling and absorption chamber extending in the vertical direction, and a gas inlet and a gas outlet that are in communication with the cooling and absorption chamber respectively, wherein the gas inlet is disposed in a lower part of the second column body to receive the process gas from the process gas outlet (113) of the reactor assembly (100), and the gas outlet is disposed in an upper part of the second column body (510);
the first absorption layer and the second absorption layer are arranged spaced apart from each other in the cooling and absorption chamber in the vertical direction, wherein the first absorption layer comprises a first spraying mechanism (520) capable of spraying an absorption fluid into the cooling and absorption chamber, and the second absorption layer comprises a second spraying mechanism (530) capable of spraying an absorption fluid into the cooling and absorption chamber.

16. The sulfur-containing waste treatment system of claim 9, wherein the oxidation and absorption unit (800) comprises a conversion device and an absorption device;
the conversion device is in communication with the drying unit (700) and configured to oxidize the fourth gas obtained in the drying unit (700) to obtain a gas containing sulfur trioxide;
the absorption device is in communication with the conversion device and configured to carry out absorption treatment on the gas containing sulfur trioxide to obtain the sulfuric acid and the exhaust gas.

17. The sulfur-containing waste treatment system of claim 16, wherein the conversion device comprises a converter (840), which comprises a converter shell (841), a catalyst bed assembly, and heat exchange pipelines (845a, 845b);

Date recue/Date received 2023-04-20 the converter shell (841) has a conversion chamber therein, and is provided with a conversion gas inlet (842a, 842b) and a conversion gas outlet (843a, 843b) that are in communication with the conversion chamber respectively, wherein the conversion gas inlet (842a, 842b) is configured to receive the process gas from the process gas outlet (113) of the reactor assembly (100);
the catalyst bed assembly comprises at least two catalyst layers (844a, 844b, 844c, 844d), which are arranged in the conversion chamber at an interval in the flow direction of the process gas;
the heat exchange pipelines (845a, 845b) match the catalyst layers (844a, 844b, 844c, 844d) in quantity, and arranged at least partially inside the conversion chamber and positioned between adjacent catalyst layers (844a, 844b, 844c, 844d).

18. A method for burning sulfur-containing waste with the reactor assembly of any of claims 1-8.

19. A method for making sulfuric acid by regenerating sulfur-containing waste, comprising:
(1) using the method of claim 18, introducing fuel and the sulfur-containing waste into the reactor assembly for combustion for at least two times in the presence of oxygen-containing combustion gas, to obtain a first gas containing sulfur dioxide;
(2) introducing the first gas into the heat recovery unit for heat recovery, to obtain a super-heated steam and a second gas;
(3) introducing the second gas into the purifying and cooling unit for purification and cooling, to obtain a third gas;
(4) introducing the third gas into the drying unit for drying, to obtain a fourth gas;
(5) introducing the fourth gas into the oxidation and absorption unit for oxidation and absorption, to obtain sulfuric acid and exhaust gas.

20. The method of claim 19, wherein the sulfur-containing waste is selected from at least one of waste sulfuric acid, sulfur-Date recue/Date received 2023-04-20 containing waste liquor, and sulfur-containing waste gas;
the fuel is selected from at least one of natural gas, sulfur, liquefied hydrocarbons, hydrogen sulfide, and heavy oil organic substances;
In the first gas, the content of sulfur dioxide is 3-12 mol%, the content of NOx is lower than or equal to 100 mg/Nm3, and the content of oxygen is 0.5-5 mol%
Date recue/Date received 2023-04-20