A rising pipe device and method for removing organic sulfur from coke oven raw gas

Abstract

The present invention discloses a riser device and method for removing organic sulfur from raw coal gas of coke oven, which belongs to the field of coking technology. By arranging a gas premixing section and a hydrodesulfurization section in the riser, turbulence is formed in the premixing chamber through the swirl disturbance of the swirl spray pipe, so that the hydrogen-rich gas and the raw coal gas are fully mixed in the gas premixing section, and then the organic sulfur is hydrogenated to form inorganic sulfur through the hydrogenation reaction catalyst bed arranged in the hydrodesulfurization section, so as to achieve the removal of organic sulfur. The production and investment costs of the device and method are low, and the organic sulfur in the coke oven gas can be removed efficiently and deeply from the source, which greatly reduces the organic sulfur content of the coking benzene product, improves the quality of the benzene product, and reduces the load and difficulty of the subsequent fine desulfurization.

Description

Technical Field

[0001] The invention belongs to the technical field of coking, and in particular relates to a rising pipe device and a method for removing organic sulfur from raw coal gas of a coke oven. Background Art

[0002] With the rapid development of my country's steel industry, high-quality coking coal resources are becoming increasingly scarce. Among coking coal resources, more than 25% of coking coal has a sulfur content of more than 1.5%. The sulfur content of domestic coking coal is lowest in young low-metamorphosis gas coal and 1 / 3 coking coal, while the sulfur content of older gas coal, fat coal and coking coal with higher metamorphism is relatively high. In order to expand coking coal resources and reduce coking costs, more and more coking enterprises have to use coking coal with a higher sulfur content. The consequences are: (1) The sulfur content in coal gas increases, resulting in excessive sulfur content in factory coal gas and coking by-products such as benzene, increasing the load of coal gas desulfurization and environmental protection management, increasing costs, and also affecting the price and sales of benzene products. (2) The sulfur content in coke increases, which reduces the quality of coke and increases ironmaking costs and environmental protection management loads.

[0003] Coke oven gas is a gaseous product produced during the high-temperature carbonization process of coal. It contains sulfides such as H2S, COS, CS2, sulfides, mercaptans and thiophene. Most of the inorganic sulfur and a very small amount of organic sulfur contained in coke oven gas can be removed during the coking wet desulfurization, while most of the organic sulfur can only be removed by the dry fine desulfurization process.

[0004] At present, in the field of new coal chemical industry, the process flow of coke oven gas fine desulfurization is generally: pre-hydrogenation, primary hydrogenation, primary fine desulfurization, secondary hydrogenation, and secondary fine desulfurization. The role of primary and secondary hydrogenation is to hydrogenate organic sulfur such as mercaptans, sulfides, and thiophene in the raw materials under the action of hydrogenation catalysts to generate inorganic sulfide H2S, which is adsorbed and removed in the secondary fine desulfurization device. The current process requires more reaction equipment, a long process, and the amount of equipment and materials takes up a large space. In addition, the current fine desulfurization methods are all after the coal gas purification process. Therefore, the coal gas before the benzene washing tower still contains most of the organic sulfur, which is the fundamental reason for the excessive sulfur content of coking benzene products. Summary of the invention

[0005] Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides a riser device for removing organic sulfur from coke oven raw gas, which can efficiently and deeply remove organic sulfur from coke oven gas from the source, reduce the organic sulfur content of coking benzene products, improve the quality of benzene products, and reduce the load and difficulty of subsequent fine desulfurization.

[0006] Another object of the present invention is to provide a method for removing organic sulfur from coke oven raw gas using the above device.

[0007] Technical solution: A riser device for removing organic sulfur from coke oven raw gas, comprising a base, a gas premixing section, a hydrodesulfurization section and a bridge pipe which are connected in sequence from bottom to top; the gas premixing section comprises a premixing chamber and a rotary spray pipe installed on the outer wall of the premixing chamber, the rotary spray pipe comprises a rotary spray inlet and a gas swirl channel, the rotary spray inlet is spiral, the gas swirl channel extends obliquely downward from the rotary spray inlet, and the lower end of the gas swirl channel is connected to the premixing chamber; the hydrodesulfurization section comprises a hydrodesulfurization chamber and a hydrogenation reaction catalyst bed arranged in the hydrodesulfurization chamber, and a hydrogenation reaction catalyst is arranged in the hydrogenation reaction catalyst bed.

[0008] Specifically, the hydrodesulfurization chamber is further provided with a gas distribution plate, a gas adsorption redistribution bed and a gas filtration bed, and the gas distribution plate, the gas adsorption redistribution bed, the hydrogenation reaction catalyst bed and the gas filtration bed are arranged in sequence from bottom to top.

[0009] The gas adsorption redistribution bed is formed by filling coke particles, and the particle size of the coke particles gradually decreases from bottom to top.

[0010] The hydrogenation reaction catalyst is a Pt-Ni-Mo-Fe-Zn based composite selective catalyst, which greatly improves the conversion rate of organic sulfur in coal gas and makes deep desulfurization of coal gas more feasible.

[0011] The rotary spray pipe also has an axial inlet, which is axially connected to the upper end of the gas cyclone channel, and the rotary spray inlet is wound around the outer periphery of the axial inlet.

[0012] There are two rotary spray pipes, which are respectively arranged on both sides of the premixing chamber and are symmetrical about the symmetry plane. The gas outlet center line of the bridge pipe is located on the symmetry plane of the two rotary spray pipes.

[0013] The projections of the two rotary spray pipes on the horizontal plane are consistent with the angle of the symmetry plane, and are both 60° to 90°.

[0014] The gas premixing section also includes a temperature measuring device and a hydrogen measuring device. The mixing ratio of the hydrogen-rich gas is timely adjusted and optimized through online temperature and hydrogen measurement.

[0015] The bridge pipe is provided with a water seal cover and a gas block. The water seal cover is closed on the top of the bridge pipe, and the gas block is installed inside the bridge pipe. A pressure regulating system is also provided inside the bridge pipe, and the pressure regulating system adjusts the opening of the gas block according to the pressure of the carbonization chamber and the gas flow rate of the rotary spray pipe. During the coking cycle, the pressure regulating system of the single chamber of the carbonization chamber is used to adapt to the pressure change caused by the change of the premixed gas flow rate.

[0016] Corresponding to the above-mentioned riser device, the method for removing organic sulfur from coke oven raw gas described in the present invention adopts the following technical solution: hydrogen-rich gas is introduced into a premixing chamber via a swirl jet, and turbulence is generated in the premixing chamber through the swirl disturbance effect of the swirl jet flow, so that the hydrogen-rich gas and the raw gas are fully mixed to form a mixed gas with a H2 mass percentage of not less than 40%; the mixed gas rises and enters the hydrodesulfurization chamber, undergoes a hydrogenation reaction through a hydrogenation reaction catalyst bed, realizes the hydrogenation conversion of organic sulfur into inorganic sulfur H2S, and completes the removal of organic sulfur.

[0017] Beneficial effect: The riser device and method for removing organic sulfur from coke oven raw gas described in the present invention, by arranging a gas premixing section and a hydrodesulfurization section in the riser, turbulence is formed in the premixing chamber through the swirl disturbance action of the swirl nozzle, so that the hydrogen-rich gas and the raw gas are fully mixed in the gas premixing section, and then the organic sulfur is hydrogenated to form inorganic sulfur through the hydrogenation reaction catalyst bed arranged in the hydrodesulfurization section, thereby realizing the removal of organic sulfur.

[0018] The device uses hydrogen-rich gas produced by coking as a hydrogen source. According to the change of hydrogen content in the raw gas of the coke oven over time, the injection amount of hydrogen-rich gas is adjusted to meet the hydrogenation needs of the raw gas during the coking cycle. The upper and lower limits of the mixing ratio are controlled by online temperature and hydrogen measurement, which can not only ensure the hydrogen concentration, but also avoid mixing too much hydrogen-rich gas, which will cause the temperature of the mixed raw gas to be lower than 500°C, thereby causing tar condensation. In addition, by mixing low-temperature hydrogen-rich gas, the raw gas can also be cooled. On the one hand, the injection amount of subsequent circulating ammonia water is reduced, and on the other hand, the temperature can be appropriately lowered to ensure that the catalyst has better reaction conditions.

[0019] The hydrogen-rich gas is injected using a rotary spray structure, which effectively ensures that the hydrogen-rich gas and the raw coal gas are fully and evenly mixed. The rotary spray structure also enhances the gas turbulence in the premixing chamber, which is beneficial to the diffusion of hydrogen and organic sulfur and the subsequent hydrogenation reaction.

[0020] After premixing, the raw coal gas mixture passes through the gas distribution plate, gas adsorption redistribution bed, hydrogenation reaction catalyst bed, and gas filtration bed in sequence. The gas adsorption redistribution bed not only achieves uniform gas distribution, but also effectively filters the coal powder and possible small amount of tar entrained in the coal gas. The gas filtration bed can effectively filter the entrained catalyst. The use of this process ensures the effect of the catalyst and extends the service life of the catalyst.

[0021] The equipment and method have low production and investment costs, can efficiently and deeply remove organic sulfur from coke oven gas from the source, greatly reduce the organic sulfur content of coking benzene products, improve the quality of benzene products, and reduce the load and difficulty of subsequent fine desulfurization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a schematic diagram of the overall structure of the riser device of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the base and gas premixing section of the riser device of the present invention;

[0024] Figure 3 Schematic diagram of the structure of the hydrodesulfurization section of the riser device of the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the rising tube device of the present invention from a top view. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] For the JN60-6 type 6m top-loading coke oven, a set of riser devices for removing organic sulfur from the coke oven raw gas is arranged on the machine side of the furnace top corresponding to each carbonization chamber. The 650-850℃ raw gas produced in the carbonization chamber is collected into the gas collecting pipe 5 through the riser device.

[0028] like Figure 1 As shown, the riser device for removing organic sulfur from raw coke oven gas comprises a base 1, a gas premixing section 2, a hydrodesulfurization section 3 and a bridge pipe 4 which are sequentially connected from bottom to top. The base 1 is installed on the furnace top surface of the carbonization chamber, and the gas premixing section 2 is installed on the upper part of the base 1.

[0029] Combination Figure 2 and Figure 4 As shown, the gas premixing section 2 includes a premixing chamber 21 and two rotary spray pipes 22 ( Figure 1 ), temperature measuring and hydrogen measuring devices 24. The rotary spray tube 22 has a rotary spray inlet 23, an axial inlet 25 and a gas swirl channel. The rotary spray inlet 23 extends downward in a spiral and is wrapped around the outer periphery of the axial inlet 25. The gas swirl channel extends obliquely downward from the tail ends of the rotary spray inlet 23 and the axial inlet 25, and the upper end of the gas swirl channel is connected to the rotary spray inlet 23 and the axial inlet 25, and the lower end is connected to the premixing chamber 21. The premixing chamber 21 is cylindrical, and the two rotary spray tubes 22 are respectively arranged on both sides of the premixing chamber 21, and are symmetrical about the symmetry plane, which is also the symmetry plane of the premixing chamber 21. The gas outlet centerline of the bridge pipe 4 is located on the symmetry plane of the two rotary spray tubes 22. The projections of the two rotary spray tubes 22 on the horizontal plane are consistent with the angle of the symmetry plane, and are both 60° to 90°. In this embodiment, the angle is 80°, and the two rotary spray tubes 22 are both arranged on the other side of the gas outlet of the premixing chamber 21 away from the bridge pipe 4.

[0030] Combination Figure 3As shown, the hydrodesulfurization section 3 includes a hydrodesulfurization chamber 31 and a gas distribution plate 33, a gas adsorption redistribution bed 34, a hydrogenation reaction catalyst bed 32 and the gas filter bed 35 which are arranged in the hydrodesulfurization chamber 31 and arranged in sequence from bottom to top.

[0031] Among them, the gas distribution plate 33 is a porous plate structure, which is densely covered with through holes. The gas adsorption redistribution bed 34 is formed by filling coke particles, and the particle size of the coke particles gradually decreases from bottom to top. The hydrogenation reaction catalyst bed 32 is provided with a hydrogenation reaction catalyst, and specifically, the hydrogenation reaction catalyst is a Pt-Ni-Mo-Fe-Zn-based composite selective catalyst. The gas filtration bed 35 is formed by filling ceramic balls.

[0032] See again Figure 1 The bridge pipe 4 is provided with a water seal cover 41 and a gas knob 42. The water seal cover 41 covers the top of the bridge pipe 4, and the gas knob 42 is installed inside the bridge pipe 4. A pressure regulating system is also provided inside the bridge pipe 4. The pressure regulating system adjusts the opening of the gas knob 42 according to the carbonization chamber pressure and the gas flow of the rotary spray pipe 22. On the one hand, it is used to realize the opening and closing of the bridge pipe 4, and on the other hand, it can realize online single-chamber pressure regulation to meet the carbonization chamber pressure, riser pressure control and smokeless coal loading. The gas outlet of the bridge pipe 4 is connected to the gas collecting pipe 5.

[0033] This embodiment also discloses a method for removing organic sulfur from raw coke gas by using the riser device. Specifically, the recycled coal gas and H2 are introduced into the premixing chamber 21 through two inlets of the rotary spray pipe 22, respectively, wherein the recycled coal gas is introduced through the rotary spray inlet 23, and H2 is introduced through the axial inlet, and the gases are preliminarily mixed through the gas cyclone channel and enter the premixing chamber 21 at a high speed. Through the rotary spray disturbance of the airflow, turbulence and a better flow field distribution are generated in the premixing chamber 21, so that the hydrogen-rich gas and the raw coal gas are fully mixed to form a mixed gas with a mass percentage of H2 of not less than 40%. Specifically, the mixing amount of the hydrogen-rich gas can be controlled by using a mathematical model of the coal gas generation amount, so that the hydrogen content in the mixed gas is not less than 40%, and the mixing ratio is timely adjusted and optimized through the online temperature measurement and hydrogen measurement device 24, so that the temperature of the mixed gas is not less than 500°C. The mixed gas rises and enters the hydrodesulfurization chamber 31, and then passes through the gas distribution plate 33 for uniform gas distribution, the gas adsorption redistribution bed 34 for primary filtration, the hydrogenation catalyst bed 32 for hydrogenation reaction, and the gas filtration bed 35 for re-filtration, so as to realize the hydrogenation conversion of organic sulfur into inorganic sulfur H2S and complete the removal of organic sulfur. The mixed raw gas after hydrogenation is also sprayed with circulating ammonia water to cool its temperature to about 80°C, and then enters the gas collecting pipe.

[0034] After the riser device of the present invention is used in this embodiment, more than 90% of the organic sulfur in the raw gas can be removed, and the sulfur content in the coking benzene product can be controlled below 500 mg / kg. The quality of the coking benzene product is improved to a higher level, and the economic benefits are correspondingly improved. In addition, the raw gas can be initially cooled, which brings additional efficiency to the subsequent cooling and treatment of the raw gas. It also reduces the load and difficulty of the subsequent fine desulfurization, shortens the fine desulfurization process, and reduces the production and investment costs.

Claims

1. A rising pipe device for removing organic sulfur from coke oven raw gas, characterized in that: The invention comprises a base (1), a gas premixing section (2), a hydrodesulfurization section (3) and a bridge pipe (4) which are sequentially connected and arranged from bottom to top; the gas premixing section (2) comprises a premixing chamber (21) and a rotary spray pipe (22) installed on the outer wall of the premixing chamber (21); the rotary spray pipe (22) comprises a rotary spray inlet (23) and a gas cyclone channel; the rotary spray inlet (23) is spiral-shaped; the gas cyclone channel extends obliquely downward from the rotary spray inlet (23); and the lower end of the gas cyclone channel is connected to the premixing chamber (21); the hydrodesulfurization section (3) comprises a hydrodesulfurization chamber (31) and a hydrogenation reaction catalyst bed (32) arranged in the hydrodesulfurization chamber (31); a hydrogenation reaction catalyst is arranged in the hydrogenation reaction catalyst bed (32); the hydrodesulfurization chamber (31) is also provided with a gas distribution plate (33), a gas absorption plate (33), and a gas absorption plate (34). A redistribution bed (34) and a gas filtration bed (35) are attached, the gas distribution plate (33), the gas adsorption redistribution bed (34), the hydrogenation reaction catalyst bed (32) and the gas filtration bed (35) are arranged in sequence from bottom to top; the gas adsorption redistribution bed (34) is formed by filling with coke particles, and the particle size of the coke particles gradually decreases from bottom to top; the hydrogenation reaction catalyst is a Pt-Ni-Mo-Fe-Zn-based composite selective catalyst; the bridge pipe (4) is provided with a water seal cover (41) and a gas ball (42), the water seal cover (41) is covered on the top of the bridge pipe (4), and the gas ball (42) is installed inside the bridge pipe (4); a pressure regulating system is also provided inside the bridge pipe (4), and the pressure regulating system adjusts the opening of the gas ball (42) according to the pressure of the carbonization chamber and the gas flow rate of the rotary spray pipe (22).

2. The rising pipe device for removing organic sulfur from coke oven raw gas according to claim 1 is characterized in that: The rotary spray pipe (22) further comprises an axial inlet (25), wherein the axial inlet (25) is axially connected to the upper end of the gas cyclone channel, and the rotary spray inlet (23) is wound around the outer periphery of the axial inlet (25).

3. The rising pipe device for removing organic sulfur from coke oven raw gas according to claim 2 is characterized in that: There are two rotary spray pipes (22), which are respectively arranged on both sides of the premixing chamber (21) and are symmetrical about the symmetry plane, and the gas outlet center line of the bridge pipe (4) is located on the symmetry plane of the two rotary spray pipes (22).

4. The rising pipe device for removing organic sulfur from coke oven raw gas according to claim 3 is characterized in that: The projections of the two rotary spray pipes (22) on the horizontal plane are consistent with the angles of the symmetry plane, and are both 60° to 90°.

5. The rising pipe device for removing organic sulfur from coke oven raw gas according to claim 1, characterized in that: The gas premixing section (2) also includes a temperature measuring device and a hydrogen measuring device (24).

6. A method for removing organic sulfur from coke oven raw gas using the riser device according to any one of claims 1 to 5, characterized in that: The hydrogen-rich gas is introduced into the premixing chamber (21) through the swirl jet (22), and turbulence is generated in the premixing chamber (21) through the swirl disturbance effect of the swirl jet flow, so that the hydrogen-rich gas and the raw coal gas are fully mixed to form a mixed gas with a H2 mass percentage of not less than 40%; the mixed gas rises and enters the hydrodesulfurization chamber (31), and undergoes a hydrogenation reaction through a hydrogenation reaction catalyst bed (32), thereby realizing the hydrogenation conversion of organic sulfur into inorganic sulfur H2S, thereby completing the removal of organic sulfur.

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