Coal gasification acid process waste gas blending combustion treatment system

Abstract

The application discloses a coal gasification acid process waste gas blending combustion treatment system, which comprises an acid process waste gas supply system, an acid process waste gas special-purpose porous burner, a steam heat tracing system and a collection control system. The acid process waste gas supply system comprises an acid process waste gas pipeline and an acid process waste gas special-purpose valve group; and the collection control system comprises a pressure transmitter, an acid process waste gas special-purpose leakage detection alarm device, an intelligent control device and a flame detector. The acid process waste gas blending combustion treatment system introduces the acid process waste gas into a four-corner tangential circle pulverized coal boiler for blending combustion disposal, and the flue gas generated after complete combustion of the waste gas enters a boiler flue gas treatment system, so that the flue gas related emission indexes can meet the requirements of the national ultra-low emission standard. The application has the characteristics of energy saving, environmental protection, low investment, low operation cost and no adverse effect on the combustion output of the pulverized coal boiler.

Description

Technical Field

[0001] The present invention relates to a waste gas treatment system, in particular to a system for treating waste gas from a coal gasification acidic process. Background Art

[0002] The coal chemical process generates several flammable, acidic waste gases containing toxic and hazardous components such as hydrogen sulfide, ammonia, benzene, naphthalene, and hydrogen cyanide. Currently, domestic coal chemical companies generally use Claus furnaces for incineration, then direct the treated flue gas into a desulfurization unit for sulfur recovery, ultimately achieving standard emissions. This treatment process has the following disadvantages: 1. Poor combustion stability: The acidic process waste gas has a low calorific value and unstable gas volume, which can lead to ignition difficulties, unstable combustion, and fire failure. 2. The acidic process waste gas has a complex composition, and its toxic, harmful, and corrosive properties have many adverse effects on the operation of the Claus furnace, often failing to meet its design lifespan. 3. Due to the immaturity of sulfur recovery technology, the flue gas composition after the reaction is complex, which can lead to deterioration in the subsequent desulfurization system. This can severely exceed emission standards, especially after the implementation of ultra-low emission treatment systems. Consequently, flaring is often required in violation of environmental regulations. 4. The Claus furnace process system has high investment costs, requires a large number of operators and maintenance personnel, and has high operating costs.

[0003] Due to the above reasons, a safe and effective treatment solution is urgently needed to replace the Claus waste gas treatment process. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a system for the co-combustion treatment of acidic process waste gas from coal gasification. This system introduces acidic process waste gas generated during the coal gasification process into a pulverized coal boiler for co-combustion treatment. The flue gas generated after combustion is then discharged through the boiler flue gas treatment system to meet emission standards. This effectively addresses the treatment challenges of acidic process waste gas generated during the coal gasification process and enables coal chemical plant emissions to meet national environmental standards. Furthermore, the present invention is energy-efficient, environmentally friendly, requires low investment and operating costs, and has no adverse impact on the combustion output of the pulverized coal boiler.

[0005] To achieve the above objectives, the present invention adopts a technical solution: a coal-to-gasification acidic process waste gas co-combustion treatment system comprising an acidic process waste gas supply system 1, a multi-hole burner 2 specifically for acidic process waste gas, a steam tracing system 3, and a collection and control system 4. The acidic process waste gas supply system 1 includes an acidic process waste gas pipeline 1-1 and a valve group 1-2 specifically for acidic process waste gas; the collection and control system 4 includes a pressure transmitter 4-1, a leak detection and alarm device 4-2 specifically for acidic process waste gas, an intelligent control device 4-3, and a flame detector 4-4.

[0006] The aforementioned system for treating acidic process waste gas from coal gasification is characterized by its application to treating acidic process waste gas generated during coal gasification. The resulting acidic process waste gas is combusted in a tangentially heated pulverized coal boiler, where it is co-combusted with pulverized coal. The ratio of acidic process waste gas to pulverized coal is approximately 1:10 (measured in terms of heat input per unit time).

[0007] The aforementioned coal-to-gas sour process waste gas co-combustion treatment system is characterized by: the sour process waste gas supply system 1 includes an sour process waste gas pipeline 1-1 and a dedicated sour process waste gas valve assembly 1-2. The sour process waste gas pipeline 1-1 and the dedicated sour process waste gas valve assembly 1-2 are made of stainless steel. The use of stainless steel pipelines and pipeline components effectively prevents corrosion of the sour process waste gas supply system by the sour process waste gas, ensuring the long-term safe operation of the system.

[0008] The above-mentioned coal-gasification and acidic process waste gas co-combustion treatment system is characterized in that the porous burner 2 dedicated to acidic process waste gas is made of heat-resistant and wear-resistant steel. The porous burner 2 dedicated to acidic process waste gas is connected to the acidic process waste gas supply system 1 and is installed inside the pulverized coal boiler burner. The porous burner 2 dedicated to acidic process waste gas can effectively control the flame diameter of the acidic process waste gas to about 0.5m. The flame length is about 2m. The use of heat-resistant and wear-resistant steel in the porous burner 2 dedicated to acidic process waste gas can enable the burner to operate safely in an environment above 900°C for a long time. The porous burner 2 dedicated to acidic process waste gas is installed in the secondary air burner in the boiler.

[0009] The aforementioned coal-to-gas acidic process waste gas co-combustion treatment system is characterized by a steam heating system 3 installed in close proximity to the acidic process waste gas supply system 1. The steam heating system 3 protects the acidic process waste gas supply system 1, maintaining the acidic process waste gas operating temperature at approximately 50°C. Acidic process waste gas has a complex composition, and at lower temperatures, crystalline flocs may form, which can cause blockage in the acidic process waste gas supply system 1. The steam heating system 3 effectively prevents this phenomenon.

[0010] The aforementioned coal-to-gas acidic process waste gas co-combustion treatment system is characterized by a data acquisition and control system 4 comprising a pressure transmitter 4-1, a dedicated acidic process waste gas leak detection and alarm device 4-2, an intelligent control device 4-3, and a flame detector 4-4. The data acquisition and control system 4 is embedded within the boiler DCS control system. Through a newly created co-combustion operation screen, it automatically controls and regulates each system, while also providing comprehensive and effective safety interlock protection.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] 1. The solution of the present invention is novel, the design is complete and reasonable, the system runs safely and reliably, and it is energy-saving and environmentally friendly.

[0013] 2. This invention directs the acidic process waste gas generated during the coal gasification process into a tangentially pulverized coal boiler for combustion. The acidic process waste gas is then burned along with the pulverized coal in the tangentially pulverized coal boiler. Because the furnace volume, temperature, and residence time of the tangentially pulverized coal boiler are far superior to those of a Claus furnace, this ensures 100% complete treatment of the acidic process waste gas. Furthermore, at a blending ratio of 1:10, the combustion of the acidic process waste gas has minimal impact on overall boiler operation.

[0014] 3. The acidic process waste gas pipeline and dedicated acidic process waste gas valve assembly used in this invention are made of stainless steel. This effectively prevents acidic process waste gas from corroding the acidic process waste gas supply system, ensuring the long-term safe operation of the system.

[0015] 4. The porous burner used in this invention is made of heat-resistant and wear-resistant steel. This allows the burner to operate safely and long-term in environments above 900°C. The porous burner is installed in the secondary air burner of the boiler.

[0016] 5. The present invention can control the temperature of the acidic process waste gas at about 50° C. by providing a steam heating system, thereby solving the blockage problem of the acidic process waste gas supply system.

[0017] 6. The present invention realizes the operation, monitoring and interlocking protection of the system by setting up an acquisition control system, ensuring the safe and stable operation, regulation and safety protection of the entire blending and combustion system.

[0018] 7. Compared with the construction of Claus furnace treatment system, the present invention has lower investment cost, better use effect, simpler system, and requires fewer operation and maintenance personnel, which is more convenient for promotion and use.

[0019] 8. The system and technology of the present invention have been successfully applied to four 480t / h pulverized coal boilers of Zhejiang Energy Xintian Coal Chemical Co., Ltd., with good operation, and won the first prize of Zhejiang Electric Power Science and Technology Progress in 2020.

[0020] In summary, the present invention has novel and reasonable design, high working reliability, long service life, low investment, low operating cost, and is easy to promote and use.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a system schematic diagram of the present invention. DETAILED DESCRIPTION

[0023] The following combination Figure 1 The structural principle and working principle of the present invention are further described in detail.

[0024] A coal-to-gasification system for the co-combustion treatment of acidic process waste gas includes an acidic process waste gas supply system 1, a porous burner 2 specifically for acidic process waste gas, a steam tracing system 3, and a collection and control system 4. The acidic process waste gas supply system 1 includes an acidic process waste gas pipeline 1-1 and a valve group 1-2 specifically for acidic process waste gas; the collection and control system 4 includes a pressure transmitter 4-1, a leak detection and alarm device 4-2 specifically for acidic process waste gas, an intelligent control device 4-3, and a flame detector 4-4.

[0025] In this embodiment, the acidic process waste gas generated during the coal gasification process is directed to a tangentially heated pulverized coal boiler for combustion. The acidic process waste gas is co-combusted with the pulverized coal in the tangentially heated pulverized coal boiler. The ratio of acidic process waste gas to pulverized coal is approximately 1:10 (based on lower heating value). This ensures 100% combustion of the acidic process waste gas.

[0026] In this embodiment, the acidic process waste gas supply system 1 includes an acidic process waste gas pipeline 1-1 and a dedicated acidic process waste gas valve assembly 1-2. Both the acidic process waste gas pipeline 1-1 and the dedicated acidic process waste gas valve assembly 1-2 are made of stainless steel. The use of stainless steel pipelines and pipeline components effectively prevents corrosion of the acidic process waste gas supply system 1 by the acidic process waste gas, ensuring long-term safe operation of the system.

[0027] In this embodiment, the porous burner 2 dedicated to acidic process waste gas is made of heat-resistant and wear-resistant steel. The porous burner 2 dedicated to acidic process waste gas is connected to the acidic process waste gas supply system 1 and is installed inside the pulverized coal boiler burner. The porous burner 2 dedicated to acidic process waste gas can effectively control the flame diameter of the acidic process waste gas to about 0.5m. The flame length is about 2m. The use of heat-resistant and wear-resistant steel in the porous burner 2 dedicated to acidic process waste gas can enable the burner to operate safely in an environment above 900°C for a long time. The porous burner 2 dedicated to acidic process waste gas is installed in the secondary air burner in the boiler.

[0028] In this embodiment, the steam tracing system 3 provides air supply protection for the gas supply system. It is installed in close proximity to the acidic process waste gas supply system 1. This system provides protection for the acidic process waste gas supply, maintaining the operating temperature of the acidic process waste gas at approximately 50°C. Acidic process waste gas has a complex composition, and at lower temperatures, crystalline flocs can form, potentially causing blockage in the acidic process waste gas supply system. The steam tracing system 3 effectively prevents this phenomenon.

[0029] In this embodiment, the data collection and control system 4 monitors and protects the safe operation of the entire system. It includes a pressure transmitter 4-1, a dedicated leak detection and alarm device for acidic process waste gas 4-2, an intelligent control device 4-3, and a flame detector 4-4. Embedded within the boiler's DCS control system, the data collection and control system 4 automatically controls and regulates each system through a newly created co-combustion operation screen. This data collection and control system 4 provides comprehensive and effective safety interlock protection for the entire coal-to-gas acidic process waste gas co-combustion treatment system. For example: when the pressure transmitter 4-1 detects that the pressure of the acidic process waste gas in the acidic process waste gas supply system 1 is greater than (or less than) the set protection value, the interlocking intelligent control device 4-3 quickly closes the acidic process waste gas dedicated valve group 1-2 to cut off the gas supply; when the flame detector 4-4 cannot detect a flame within 3 seconds after the gas supply system 1 starts supplying gas, the interlocking intelligent control device 4-3 controls the acidic process waste gas dedicated valve group 1-2 to quickly close and cut off the gas supply; when the acidic process waste gas dedicated leakage detection and alarm device 4-2 detects a leak in the acidic process waste gas supply system 1, the interlocking intelligent control device 4-3 controls the acidic process waste gas dedicated valve group 1-2 to quickly close and cut off the gas supply.

[0030] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A coal gasification acidic process waste gas co-combustion treatment device, characterized in that: The device is composed of an acidic process waste gas supply system (1), a multi-hole burner (2) dedicated for acidic process waste gas, a steam tracing system (3), and a collection and control system (4). The acidic process waste gas supply system (1) includes an acidic process waste gas pipeline (1-1) and a valve group (1-2) dedicated for acidic process waste gas. The acidic process waste gas pipeline (1-1) is connected to the valve group (1-2) dedicated for acidic process waste gas. The multi-hole burner (2) dedicated for acidic process waste gas is connected to the acidic process waste gas supply system (1) and is installed inside a pulverized coal boiler burner. The steam tracing system (3) is installed around the acidic process waste gas supply system (1). The collection and control system (4) includes a pressure transmitter (4-1), a leakage detection and alarm device (4-2) dedicated for acidic process waste gas, an intelligent control device (4-3), and a flame detector (4-4). The acidic process waste gas generated in the coal gasification process is introduced into a tangential pulverized coal boiler and burned together with the pulverized coal for treatment, and the flue gas generated after the waste gas is burned is discharged in compliance with the emission standards through the boiler flue gas treatment system; the heat entering the furnace per unit time is measured, and the mixing ratio of the acidic process waste gas and the pulverized coal is 1:10; the porous burner (2) dedicated to the acidic process waste gas is installed in the secondary air burner of the boiler, and its performance needs to ensure that the acidic process waste gas can be ignited in time and burned stably, can effectively control the flame diameter to be 0.5m and the flame length to be 2m, and minimize the impact on the performance of the original pulverized coal burner.

2. The device according to claim 1, characterized in that The acidic process waste gas pipeline (1-1) and the acidic process waste gas dedicated valve group (1-2) are both made of stainless steel. The use of stainless steel pipelines and valve groups can effectively prevent the acidic process waste gas from corroding the acidic process waste gas supply system (1), thereby ensuring the long-term safe operation of the system.

3. The device according to claim 1, characterized in that The multi-hole burner (2) specially designed for acidic process waste gas is made of heat-resistant and wear-resistant steel, which enables the burner to operate safely in an environment above 900° C. for a long time.

4. The device according to claim 1, characterized in that The steam heating system (3) is an acidic process waste gas supply and protection system, which can control the temperature of the acidic process waste gas in the pipeline to 50°C.

5. The device according to claim 1, characterized in that The acquisition and control system (4) is embedded in the boiler DCS control system, and completes the automatic control and operation adjustment of each system through the newly created co-combustion operation screen. The acquisition and control system (4) provides comprehensive and effective safety interlock protection for the entire coal-to-gas acidic process waste gas co-combustion treatment system.

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