A coking process that provides incomplete oxidation for heating while producing hydrogen-rich reducing gas as a byproduct.

Abstract

This invention relates to a coking process that uses incomplete oxidation for heating while simultaneously producing hydrogen-rich reducing gas as a byproduct. By optimizing the overall coking process and guiding the airflow within the furnace, the raw coal gas undergoes primary and secondary reactions. The primary reaction is an incomplete oxidation reaction where oxygen enters the furnace and comes into contact with the high-temperature coke oven gas, releasing a large amount of heat to heat the carbonization chamber and the first secondary reaction zone. Due to the incomplete oxidation combustion, the unburned methane, H2O, and CO2 from the primary reaction enter the secondary reaction zone. In the secondary reaction zone, the remaining methane reacts with H2O and CO2 to produce CO and H2. This secondary reaction is endothermic, producing hydrogen-rich reducing gas. The beneficial effects of this invention are that it avoids heat loss during the high-temperature raw coal gas treatment process, converts a large amount of raw coal gas into hydrogen and carbon monoxide, greatly improves the resource utilization of raw coal gas, increases its utilization rate, and protects the ecological environment.

Description

Technical Field

[0001] This invention relates to the field of incomplete oxidation coking by-product hydrogen-rich reducing gas technology, and particularly to a coking process that provides heating through incomplete oxidation while simultaneously producing hydrogen-rich reducing gas as a by-product. Background Technology

[0002] Vertical heat recovery coke ovens completely burn the raw coal gas, and the large amount of hot flue gas generated is used for waste heat recovery and power generation. After cooling, the flue gas is purified and discharged into the atmosphere through the chimney. All the hydrogen in the raw coal gas is burned into carbon dioxide and water vapor, which is a huge waste of hydrogen resources and the hydrogen is not fully utilized. At the same time, a large amount of CO2 and other pollutants from the coke oven flue gas are emitted from the chimney, causing damage to the atmospheric environment and affecting the surrounding ecological environment. Summary of the Invention

[0003] To address the technical problems existing in the prior art, this invention provides a coking process that simultaneously generates hydrogen-rich reducing gas as a byproduct through incomplete oxidation heating. By optimizing the overall coking process and guiding the airflow within the furnace, the raw coal gas undergoes an incomplete oxidation reaction, heating the coal in the carbonization chamber while simultaneously being converted into low-carbon, hydrogen-rich reducing gas. This significantly reduces carbon dioxide emissions during the coking process, preventing surrounding pollution. The hydrogen-rich reducing gas, obtained through a secondary reaction, can be directly used as a reducing agent in hydrogen metallurgy in integrated iron and steel enterprises, or used for hydrogen extraction or as syngas in independent coking plants, maximizing the utilization of raw coal gas resources.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A coking process that provides heat through incomplete oxidation while simultaneously producing hydrogen-rich reducing gas as a byproduct includes the following steps:

[0006] 1) The raw coal gas generated during the dry distillation of coal in the coke oven carbonization chamber enters the adjacent primary reaction zone of the carbonization chamber from the top of the partition wall.

[0007] 2) The externally supplied oxygen is preheated by the oxygen preheater and then depressurized. After depressurization, it is mixed with carbon dioxide and water vapor in the pipeline mixer and enters the top of the primary reaction zone through the flow regulating valve and oxygen nozzle. It encounters the raw coal gas escaping from the carbonization chamber in the primary reaction zone and undergoes an incomplete oxidation primary reaction. While the primary reaction releases a large amount of heat, it also heats the coal in the carbonization chamber and the secondary reaction zone through the partition wall.

[0008] 3) After the raw coal gas and oxygen mixture undergoes incomplete oxidation in the primary reaction zone, it enters the secondary reaction zone 1 through the lower channel to carry out the secondary reaction. The methane that is not completely burned after the raw coal gas undergoes incomplete oxidation reacts with H2O and CO2 in the mixture under high temperature to produce a mixed gas containing hydrogen reducing gas. A large amount of heat is absorbed during the secondary reaction.

[0009] 4) The mixed gas containing hydrogen reducing gas escapes from the top of the first secondary reaction zone and enters the second secondary reaction zone at the top. It passes through the "snake-shaped" gas channel formed by the second secondary reaction zone, which prolongs the secondary reaction time and increases the reduction rate of H2O and CO2. The mixed gas is reduced to hydrogen-rich reducing gas.

[0010] 5) The hydrogen-rich reducing gas that passes through the second zone of the secondary reaction enters the waste heat boiler through a high-temperature pipeline. In the waste heat boiler, it passes through the slag condenser, superheater, saturator and economizer in sequence. A portion of the steam returns to the pipeline mixer to be used to prepare oxygen, and most of the high-temperature and high-pressure superheated steam is recovered and reused.

[0011] 6) After passing through the waste heat boiler, the hydrogen-rich reducing gas is washed and cooled by water. It is then pressurized by a fan and enters the desulfurization and decarbonization purification process. After purification, the hydrogen-rich reducing gas product is obtained. The separated CO2-containing components are returned to the pipeline mixer for oxygen preparation.

[0012] Furthermore, in step 2), the oxygen preheater preheats the oxygen to 160-180°C.

[0013] Furthermore, in step 2), the decompression is to reduce the oxygen pressure to 30-100 kPag.

[0014] Furthermore, in step 3), the secondary reaction zone 1 is carried out at 1100–1400°C.

[0015] Furthermore, in step 4), the secondary reaction zone 2 is carried out at a temperature above 1000°C.

[0016] Furthermore, the waste heat boiler is a vertical boiler, with water temperature above 104℃ and pressure of 10 MPag, producing high-temperature and high-pressure superheated steam at 500-550℃ and 9.81 MPag.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The high-temperature raw coal gas produced by coking directly undergoes an incomplete oxidation reaction with oxygen, avoiding heat loss during the processing of high-temperature raw coal gas. A large amount of raw coal gas is converted into hydrogen and carbon monoxide, greatly improving the resource utilization of raw coal gas and increasing its utilization rate.

[0019] 2. The water vapor and CO2 generated during the production of hydrogen-rich reducing gas are returned to the pipeline mixer to mix with oxygen, reducing the oxygen concentration. This allows for the control of the incomplete oxidation reaction between the raw coal gas and low-concentration oxygen in the primary reaction zone without external intervention, saving on process configuration and economic costs. Water vapor and CO2 are not released externally, thus preventing environmental pollution and protecting the ecological environment.

[0020] 3. Hydrogen-rich reducing gas can be directly used as a reducing agent in the field of hydrogen metallurgy in integrated iron and steel enterprises. In independent coking enterprises, it can be used for hydrogen extraction or as syngas to produce bulk chemical commodities, resulting in significant economic benefits. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a coking process described in this invention, which involves incomplete oxidation for heating while simultaneously producing hydrogen-rich reducing gas as a byproduct.

[0022] Figure 2 This is a top view of the "snake-shaped" airway layout in the second-stage reaction zone provided by the present invention.

[0023] In the diagram: 1-Oxygen 2-Oxygen preheater 3-Pressure reducing valve 4-Flow regulating valve 5-Oxygen nozzle 6-Primary reaction zone 7-Secondary reaction zone 1 8-Secondary reaction zone 2 9-High temperature pipeline 10-Waste heat boiler 11-Slag condensation pipe 12-Superheater 13-Saturator 14-Economic gas 15-Water washing cooling 16-Fan 17-Desulfurization and decarbonization 18-Sulfur-containing composition 19-CO2-containing composition 20-Hydrogen-rich reducing gas product 21-Pipeline mixer 22-Carbon dioxide and water vapor 23-Carbonation chamber 24-Raw coal gas 25-Mixed gas 26-Hydrogen-containing reducing gas 27-"Serpentine" gas duct 28-Hydrogen-rich reducing gas 29-Water vapor 30-High temperature and high pressure superheated steam 31-Boiler water supply Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0025] like Figures 1-2As shown, the working principle of a coking process that uses incomplete oxidation for heating while simultaneously producing hydrogen-rich reducing gas as a byproduct is as follows: The incomplete oxidation reaction of raw coking coal gas is an extremely complex reaction system in which series and parallel reactions coexist. According to the chemical reaction characteristics, it can be simply divided into first-order and second-order reactions. The first-order reaction is the incomplete oxidation reaction in which oxygen enters the furnace and comes into contact with the high-temperature coking coal gas, heating the carbonization chamber and the first zone of the second-order reaction. The combustible components in this zone are rapidly and completely burned under high temperature and high oxygen concentration, releasing a large amount of heat. This process is extremely fast. Because it is incomplete oxidation combustion, there are unburned combustible components after the first-order reaction. These combustible components, along with H2O and CO2, enter the second-order reaction zone. In the second-order reaction zone, the methane in the remaining combustible components undergoes a second-order reaction with H2O and CO2 to produce CO and H2. This second-order reaction is an endothermic reaction, and the main product is hydrogen-rich reducing gas.

[0026] like Figures 1-2 As shown, a coking process that provides heat through incomplete oxidation while simultaneously producing hydrogen-rich reducing gas as a byproduct includes the following steps:

[0027] 1) The raw coal gas 24 generated during the dry distillation of coal in the coke oven carbonization chamber 23 enters the primary reaction zone 6 adjacent to the carbonization chamber 23 from the top of the partition wall;

[0028] 2) The externally supplied oxygen 1 is preheated by the oxygen preheater 2 and then depressurized by the pressure reducing valve 3. After depressurization, it is mixed with carbon dioxide and water vapor 22 in the pipeline mixer 21 and enters the top of the primary reaction zone 6 through the flow regulating valve 4 and the oxygen nozzle 5. It meets the raw coal gas 24 escaping from the carbonization chamber 23 in the primary reaction zone 6 and undergoes an incomplete oxidation primary reaction. While the primary reaction releases a large amount of heat, it heats the coal in the carbonization chamber 23 and the secondary reaction zone 7 through the partition wall.

[0029] 3) After the incomplete oxidation reaction of the raw coal gas 24 and oxygen 1 mixture 25 in the primary reaction zone 6, it enters the secondary reaction zone 7 through the lower channel to carry out the secondary reaction. The methane that is not completely burned after the incomplete oxidation of the raw coal gas undergoes a secondary reaction with H2O and CO2 in the mixture under high temperature, producing a mixed gas containing hydrogen reducing gas 26. A large amount of heat is absorbed during the secondary reaction.

[0030] 4) The mixed gas containing hydrogen reducing gas 26 escapes from the top of the first secondary reaction zone 7 and enters the second secondary reaction zone 8 at the top. It passes through the "snake-shaped" gas channel 27 formed by the second secondary reaction zone 8, which prolongs the secondary reaction time, increases the reduction rate of H2O and CO2, and generates hydrogen-rich reducing gas 28.

[0031] 5) The hydrogen-rich reducing gas 28, after passing through the secondary reaction zone 2, enters the waste heat boiler 10 through the high-temperature pipeline 9. In the waste heat boiler 10, it passes through the slag condenser 11, superheater 12, saturator 13, and economizer 14 in sequence. A portion of the steam 29 returns to the pipeline mixer 21 for oxygen preparation, and most of the high-temperature and high-pressure superheated steam 30 is recovered and reused.

[0032] 6) The hydrogen-rich reducing gas 28 is washed and cooled by water after passing through the waste heat boiler 10. It is then pressurized by the fan 16 and enters the desulfurization and decarbonization 17 for purification. After purification, the hydrogen-rich reducing gas product 20 is obtained. The CO2-containing component 19 after separation is returned to the pipeline mixer for oxygen preparation.

[0033] Furthermore, in step 2), the oxygen preheater 2 preheats the oxygen 1 to 160-180°C.

[0034] Furthermore, in step 2), the decompression is performed by reducing the oxygen 1 to 30-100 kPag.

[0035] Furthermore, in step 3), the secondary reaction zone 7 is carried out at 1100–1400°C.

[0036] Furthermore, in step 4), the secondary reaction zone 8 is carried out at a temperature above 1000°C.

[0037] Furthermore, the waste heat boiler 10 is a vertical boiler, with the water temperature 31 above 104℃ and the pressure 10 MPag, producing high-temperature and high-pressure superheated steam 30 at 500-550℃ and 9.81 MPag.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and concept of the present invention, should be covered within the scope of protection of the present invention.

[0039] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0040]

Example 1

[0041] like Figures 1-2As shown, oxygen 1 is mixed with carbon dioxide and water vapor 22 in pipeline mixer 21 via oxygen preheater 2 and pressure reducing valve 3, and then generates hydrogen-rich reducing gas 28 via flow regulating valve 4, oxygen nozzle 5, carbonization chamber 23, primary reaction zone 6, secondary reaction zone 1 7 and secondary reaction zone 2 8. Primary reaction zone 6 and secondary reaction zone 1 7 are set on both sides of carbonization chamber 23. Primary reaction zone 6 is connected to the top of carbonization chamber 23, secondary reaction zone 1 7 is not connected to carbonization chamber 23, and primary reaction zone 6 and secondary reaction zone 1 7 are connected at the bottom.

[0042] Oxygen 1 is preheated to 160°C by oxygen preheater 2 and reduced to 30 kPag by pressure reducing valve 3. It is then mixed with carbon dioxide and water vapor 22. The mixed gas with reduced oxygen concentration passes through flow regulating valve 4 and is then vertically sprayed downward from the top of primary reaction zone 6 by oxygen nozzle 5. The mixed gas of oxygen 1, carbon dioxide and water vapor 22 undergoes an incomplete oxidation reaction with the raw coal gas escaping from carbonization chamber 23. The heat released by the incomplete oxidation reaction heats carbonization chamber 23 and secondary reaction zone 7.

[0043] The mixed gas after the incomplete oxidation reaction enters the secondary reaction zone 7 through the lower hole of the bottom partition wall of the primary reaction zone 6. The temperature of the secondary reaction zone 7 is 1100℃. At high temperature, the mixed gas undergoes a secondary reaction with the incompletely oxidized and unburned methane, H2O and CO2 to produce a mixed gas containing hydrogen reducing gas 26. The reduction rate of H2O and CO2 is greater than 46%.

[0044] The hydrogen-containing reducing gas 26 escapes from the top of the first secondary reaction zone 7 into the second secondary reaction zone 8. The temperature of the second secondary reaction zone 8 is 1050℃. The hydrogen-containing reducing gas 26 flows in the "serpentine" gas channel 27 in the second secondary reaction zone 8, bypassing the oxygen nozzle 5 at the top of the first primary reaction zone 6. The "serpentine" gas channel 27 lengthens the flow path of the hydrogen-containing reducing gas 26, prolonging the time for methane to carry out the second secondary reaction with H2O and CO2 at high temperature. The hydrogen-containing reducing gas 26 passing through the second secondary reaction zone 8 is generated into hydrogen-rich reducing gas 28, and the reducing gas content in the hydrogen-rich reducing gas 28 is greater than 59% (dry basis).

[0045] Hydrogen-rich reducing gas 28 enters the vertical waste heat boiler 10 through the high-temperature pipeline 9. In the vertical waste heat boiler 10, it passes through the slag condenser 11, superheater 12, saturator 13, and economizer 14 in sequence. The temperature of the hydrogen-rich reducing gas 28 is reduced to 140℃, the water temperature is 104℃, and the water pressure is 10 MPag. High-temperature and high-pressure superheated steam 30 with a temperature of 550℃ and a pressure of 9.81 MPag is produced. A portion of the high-temperature and high-pressure superheated steam 30 is returned to the pipeline mixer 21 to be mixed with oxygen in a proportionate ratio, and a portion is used for waste heat power generation or direct hydrogen production.

[0046] After passing through the waste heat boiler 10, the hydrogen-rich reducing gas 28 is washed and cooled by water to a temperature of 20°C. Then, it undergoes desulfurization and decarbonization 17 to obtain hydrogen-rich reducing gas (syngas) product 20, CO2-containing component 19, and sulfur-containing component 18. The separated CO2-containing component 19 is partially returned to the pipeline mixer 21 for the preparation of oxygen.

[0047]

Example 2

[0048] like Figures 1-2 As shown, oxygen 1 is mixed with carbon dioxide and water vapor 22 in pipeline mixer 21 via oxygen preheater 2 and pressure reducing valve 3, and then generates hydrogen-rich reducing gas 28 via flow regulating valve 4, oxygen nozzle 5, carbonization chamber 23, primary reaction zone 6, secondary reaction zone 1 7 and secondary reaction zone 2 8. Primary reaction zone 6 and secondary reaction zone 1 7 are set on both sides of carbonization chamber 23. Primary reaction zone 6 is connected to the top of carbonization chamber 23, secondary reaction zone 1 7 is not connected to carbonization chamber 23, and primary reaction zone 6 and secondary reaction zone 1 7 are connected at the bottom.

[0049] Oxygen 1 is preheated to 160°C by oxygen preheater 2 and reduced to 30 kPag by pressure reducing valve 3. It is then mixed with carbon dioxide and water vapor 22. The mixed gas with reduced oxygen concentration passes through flow regulating valve 4 and is then vertically sprayed downward from the top of primary reaction zone 6 by oxygen nozzle 5. The mixed gas of oxygen 1, carbon dioxide and water vapor 22 undergoes an incomplete oxidation reaction with the raw coal gas escaping from carbonization chamber 23. The heat released by the incomplete oxidation reaction heats carbonization chamber 23 and secondary reaction zone 7.

[0050] The mixed gas after the incomplete oxidation reaction enters the secondary reaction zone 7 through the lower hole of the bottom partition wall of the primary reaction zone 6. The temperature of the secondary reaction zone 7 is 1400℃. At high temperature, the mixed gas undergoes a secondary reaction with the incompletely oxidized and unburned methane, H2O and CO2 to produce a mixed gas containing hydrogen reducing gas 26. The reduction rate of H2O and CO2 is greater than 61%.

[0051] The mixed gas containing hydrogen reducing gas 26 escapes from the top of the first secondary reaction zone 7 into the second secondary reaction zone 8. The temperature of the second secondary reaction zone 8 is 1290℃. The hydrogen reducing gas 26 flows in the "serpentine" gas channel 27 in the second secondary reaction zone 8, bypassing the oxygen nozzle 5 at the top of the first primary reaction zone 6. The "serpentine" gas channel 27 lengthens the flow path of the hydrogen reducing gas 26, prolonging the time for methane to carry out the second secondary reaction with H2O and CO2 at high temperature. The hydrogen reducing gas 26 passing through the second secondary reaction zone 8 is generated into hydrogen-rich reducing gas 28, and the reducing gas content in the hydrogen-rich reducing gas 28 is greater than 74% (dry basis).

[0052] Hydrogen-rich reducing gas 28 enters the vertical waste heat boiler 10 through the high-temperature pipeline 9. In the vertical waste heat boiler 10, it passes through the slag condenser 11, superheater 12, saturator 13, and economizer 14 in sequence. The temperature of the hydrogen-rich reducing gas 28 is reduced to 140℃, the water temperature is 104℃, and the water pressure is 10 MPag. High-temperature and high-pressure superheated steam 30 with a temperature of 550℃ and a pressure of 9.81 MPag is produced. A portion of the high-temperature and high-pressure superheated steam 30 is returned to the pipeline mixer 21 to be mixed with oxygen in a proportionate ratio, and a portion is used for waste heat power generation or direct hydrogen production.

[0053] After passing through the waste heat boiler 10, the hydrogen-rich reducing gas 28 is washed and cooled by water to a temperature of 20°C. Then, it undergoes desulfurization and decarbonization 17 to obtain hydrogen-rich reducing gas (syngas) product 20, CO2-containing component 19, and sulfur-containing component 18. The separated CO2-containing component 19 is partially returned to the pipeline mixer 21 for the preparation of oxygen.

Claims

1. A coking process which produces heat from incomplete oxidation while simultaneously producing a hydrogen-rich reducing gas as a by-product, characterized in that, Includes the following steps: 1) The raw coal gas generated during the dry distillation of coal in the coke oven carbonization chamber enters the adjacent primary reaction zone of the carbonization chamber from the top of the partition wall. 2) The externally supplied oxygen is preheated by the oxygen preheater and then depressurized. After depressurization, it is mixed with carbon dioxide and water vapor in the pipeline mixer and enters the primary reaction zone through the flow regulating valve and oxygen nozzle. It encounters the raw coal gas escaping from the carbonization chamber in the primary reaction zone and undergoes an incomplete oxidation primary reaction. While the primary reaction releases a large amount of heat, it also heats the coal in the carbonization chamber and the secondary reaction zone through the partition wall. 3) After the raw coal gas and oxygen mixture undergoes incomplete oxidation in the primary reaction zone, it enters the secondary reaction zone 1 through the lower channel to carry out the secondary reaction. The methane that is not completely burned after the raw coal gas undergoes incomplete oxidation reacts with H2O and CO2 in the mixture under high temperature to produce a mixed gas containing hydrogen reducing gas. A large amount of heat is absorbed during the secondary reaction. 4) The mixed gas containing hydrogen reducing gas escapes from the top of the first secondary reaction zone and enters the second secondary reaction zone at the top. It passes through the "snake-shaped" gas channel formed in the second secondary reaction zone, which prolongs the secondary reaction time, increases the reduction rate of H2O and CO2, and generates hydrogen-rich reducing gas. 5) The hydrogen-rich reducing gas from the second reaction zone enters the waste heat boiler through a high-temperature pipeline. In the waste heat boiler, it passes through the slag condenser, superheater, saturator, and economizer in sequence. A portion of the steam returns to the pipeline mixer to be used to prepare oxygen, while most of the high-temperature and high-pressure superheated steam is recovered and reused. 6) After passing through the waste heat boiler, the hydrogen-rich reducing gas is washed and cooled by water. It is then pressurized by a fan and enters the desulfurization and decarbonization purification process. After purification, the hydrogen-rich reducing gas product is obtained. The separated CO2-containing components are returned to the pipeline mixer for oxygen preparation.

2. The coking process according to claim 1, which provides incomplete oxidation heating while simultaneously producing hydrogen-rich reducing gas as a byproduct, is characterized in that... In step 2), the oxygen preheater preheats the oxygen to 160-180°C.

3. The coking process according to claim 1, which provides incomplete oxidation heating while simultaneously producing hydrogen-rich reducing gas as a byproduct, is characterized in that... In step 2), the decompression is to reduce the oxygen pressure to 30-100 kPag.

4. The coking process according to claim 1, which involves incomplete oxidation for heating while simultaneously producing hydrogen-rich reducing gas as a byproduct, is characterized in that... In step 3), the secondary reaction zone 1 is carried out at 1100–1400 °C.

5. The coking process according to claim 1, which provides incomplete oxidation heating while simultaneously producing hydrogen-rich reducing gas as a byproduct, is characterized in that... In step 4), the secondary reaction zone 2 is carried out at a temperature above 1000°C.

6. The coking process according to claim 1, which provides incomplete oxidation heating while simultaneously producing hydrogen-rich reducing gas as a byproduct, is characterized in that... The waste heat boiler is a vertical boiler with water temperature above 104℃ and pressure of 10 MPag, producing high-temperature and high-pressure superheated steam at 500-550℃ and 9.81 MPag.

Images