Staged gasification device and staged gasification method

Abstract

The present invention provides a staged gasification device and method. The staged gasification device includes: a primary gasification unit (1); a separation device (2) disposed downstream of the primary gasification unit (1) and communicating with the primary gasification unit (1); a secondary gasification unit (3) disposed downstream of the separation device (2) and communicating with the separation device (2), wherein the secondary gasification unit (3) includes a secondary gasification furnace chamber (33); a raw gas inlet, a hot semi-coke inlet, a second gasifying agent inlet, a final gas outlet, and a bottom slag outlet are provided on the secondary gasification furnace chamber (33); a burner (31) is located on the side wall of the secondary gasification furnace (33), and the position of the burner 31 is higher than the position of the final gas outlet; and an annular air box (32) is disposed between the raw gas outlet and the raw gas inlet of the separation device (2) for distributing the raw gas (E).

Description

[0001] This application is a divisional application. The application number of the parent case is: 202010868257.4, the application date is: August 26, 2020, and the title is: Hierarchical gasification device and hierarchical gasification method. Technical Field

[0002] The present invention relates to the technical field of fuel gasification, and specifically, to a hierarchical gasification device and a hierarchical gasification method. Background Art

[0003] Coal gasification technology is an important part of clean coal technology and one of the main ways to efficiently and cleanly utilize coal, and has become the core technology of many modern energy and chemical systems. Fluidized bed gasification can achieve good backmixing and contact between the gasifying agent and the fuel, and can use wide-screen crushed coal particles as fuel, with strong coal type adaptability; however, fluidized bed gasification is restricted by the conditions of the particles being in a fluidized state and generally can only operate below 1000°C, with a relatively low gasification reaction rate, resulting in a relatively low carbon conversion rate. Entrained flow coal gasification process has high reaction temperature, high gasification intensity, large production capacity, and high carbon conversion rate, and is the main development direction of current coal gasification technology, but there are problems such as small particle size of the pulverized coal entering the furnace, high preparation cost, and large restrictions on coal types. In order to solve the deficiencies of the above gasification processes, a hierarchical gasification process is proposed: the hierarchical gasification process combines the advantages of different reactors and gasification processes to achieve hierarchical control of the coal gasification reaction process, reduce the fuel preparation cost, increase the average reaction temperature of the system, and achieve efficient gasification.

[0004] In the actual application process of the existing hierarchical gasification technology, the following limitations exist:

[0005] (1) When operating under the conditions of a temperature lower than 950°C and a low oxygen-to-coal ratio, the gas generated in the primary gasification unit contains tar. If it directly enters the downstream, it will affect the operating stability of the downstream equipment and cause environmental pollution; in addition, the fly ash carried in the gas generated in the primary gasification unit directly leaves the system, and the fly ash has a high carbon content, which affects the overall carbon conversion rate of the system.

[0006] (2) The gas generated in the primary gasification unit enters the secondary gasification unit together with the carried fly ash and undergoes a gasification reaction with the gasifying agent introduced into the gasification furnace. If the reaction temperature in the gasification furnace is not sufficient to instantly complete the reduction reaction of the carbon with CO2 and water vapor, the gasifying agent is more likely to undergo an oxidation reaction with the combustible gases (CH4, CO, H2, etc.) in the reducing flue gas, which will reduce the gasification indexes such as the overall carbon conversion rate, cold gas efficiency, and effective gas yield of the system. Summary of the Invention

[0007] The purpose of the present invention is to at least partially overcome the defects of the prior art and provide a new hierarchical gasification device and a hierarchical gasification method.

[0008] It is still an object of the present invention to provide a staged gasification device and a staged gasification method to improve the carbon conversion rate.

[0009] It is still an object of the present invention to provide a staged gasification device and a staged gasification method which can improve the operating stability of the system.

[0010] It is still an object of the present invention to provide a staged gasification device and a staged gasification method which can improve the gasification performance of the system.

[0011] To achieve the above object or one of the objects, the technical solution of the present invention is as follows:

[0012] A staged gasification device, the staged gasification device comprising:

[0013] A primary gasification unit;

[0014] A separation device, the separation device being arranged downstream of the primary gasification unit and communicating with the primary gasification unit; and

[0015] A secondary gasification unit, the secondary gasification unit being arranged downstream of the separation device and communicating with the separation device,

[0016] wherein the separation device is configured to at least partially achieve gas-solid separation of the products of the primary gasification unit to form raw gas and hot semicoke, and

[0017] wherein the secondary gasification unit includes a separated raw gas inlet and a hot semicoke inlet.

[0018] According to a preferred embodiment of the present invention, in the flow direction of the main gas flow of the secondary gasification unit, the hot semicoke inlet is arranged upstream of the raw gas inlet.

[0019] According to a preferred embodiment of the present invention, the primary gasification unit includes a fuel inlet, a first gasifying agent inlet and a gas-solid mixture outlet;

[0020] The separation device includes a material inlet, a raw gas outlet and a hot semicoke outlet;

[0021] The secondary gasification unit includes a secondary gasification furnace chamber, and the secondary gasification furnace chamber is provided with the raw gas inlet, the hot semicoke inlet, a second gasifying agent inlet, a final gas outlet and a bottom slag outlet,

[0022] wherein the gas-solid mixture outlet of the primary gasification unit is communicated with the material inlet of the separation device, the raw gas outlet of the separation device is communicated with the raw gas inlet of the secondary gasification unit, and the hot semicoke outlet of the separation device is communicated with the hot semicoke inlet of the secondary gasification unit.

[0023] According to a preferred embodiment of the present invention, the hot semi-coke inlet of the secondary gasification unit is located at the top of the secondary gasification unit, the second gasifying agent inlet of the secondary gasification unit is located at the top of the secondary gasification unit, and the raw gas inlet of the secondary gasification unit is located on the side wall of the secondary gasification unit.

[0024] According to a preferred embodiment of the present invention, the distance between the position of the raw gas inlet and the top of the secondary gasification unit is 1 / 3 - 1 / 4 of the total height of the secondary gasification unit, and the position of the raw gas inlet is higher than the position of the final gas outlet of the secondary gasification unit.

[0025] According to a preferred embodiment of the present invention, the central axis of the raw gas inlet forms an angle less than 90 degrees with the side wall of the secondary gasification unit.

[0026] According to a preferred embodiment of the present invention, the separation device is a downward exhaust type cyclone separation device.

[0027] According to a preferred embodiment of the present invention, the number of the raw gas inlets is multiple, and the intersection point of the extension lines of the central axes of the multiple raw gas inlets is not lower than the position of the final gas outlet.

[0028] According to a preferred embodiment of the present invention, the secondary gasification furnace chamber includes two cylindrical sections with unequal diameters. The diameter of the upper cylindrical section is smaller than that of the lower cylindrical section. The hot semi-coke inlet and the second gasifying agent inlet are arranged at the top of the upper cylindrical section, and the raw gas inlet is arranged on the lower cylindrical section.

[0029] According to a preferred embodiment of the present invention, the staged gasification device further includes an annular air box, which is arranged between the raw gas outlet of the separation device and the raw gas inlet of the secondary gasification unit for distributing the raw gas.

[0030] According to a preferred embodiment of the present invention, the annular air box is arranged above the lower cylindrical section, and the raw gas inlet is arranged at the top of the lower cylindrical section, so that the raw gas distributed by the annular air box enters the secondary gasification furnace chamber from the top of the lower cylindrical section.

[0031] According to a preferred embodiment of the present invention, the staged gasification device further includes a burner, which is arranged at the top of the secondary gasification furnace chamber.

[0032] According to a preferred embodiment of the present invention, the burner is arranged at the top of the upper cylindrical section, and the raw gas inlet is arranged at the top of the lower cylindrical section.

[0033] According to a preferred embodiment of the present invention, the angle between the central axis of the raw gas inlet and the top wall of the secondary gasification furnace chamber satisfies: 90° ≤ α ≤ 135°.

[0034] According to a preferred embodiment of the present invention, the annular air box is arranged on the outer periphery of the lower cylindrical section, and the raw gas inlet is arranged on the side wall of the lower cylindrical section, so that the raw gas after being distributed by the annular air box enters the secondary gasification furnace chamber from the side wall of the lower cylindrical section.

[0035] According to a preferred embodiment of the present invention, the included angle between the central axis of the raw gas inlet and the side wall of the secondary gasification furnace chamber satisfies: 0° < δ ≤ 90°.

[0036] According to a preferred embodiment of the present invention, the annular air box includes an annular gap, and the raw gas after being distributed by the annular air box vertically enters the secondary gasification furnace chamber along the annular gap.

[0037] According to a preferred embodiment of the present invention, the secondary gasification furnace chamber includes a partition board, and the partition board divides the secondary gasification furnace chamber into a central area and a heat insulation area surrounding the central area.

[0038] According to a preferred embodiment of the present invention, the raw gas introduced into the secondary gasification furnace chamber through the raw gas inlet enters the heat insulation area, and the second gasification agent introduced into the secondary gasification furnace chamber through the second gasification agent inlet and the hot semi-coke introduced into the secondary gasification furnace chamber through the hot semi-coke inlet enter the central area.

[0039] According to a preferred embodiment of the present invention, the separation device is a horizontal separation device.

[0040] According to a preferred embodiment of the present invention, the staged gasification device further includes a burner, the burner is located on the side wall of the secondary gasification furnace chamber, and the position of the burner is higher than the position of the end gas outlet.

[0041] According to a preferred embodiment of the present invention, the number of the burners is multiple, and the multiple burners are circumferentially and evenly arranged.

[0042] According to a preferred embodiment of the present invention, the raw gas inlet of the secondary gasification unit is located at the top of the secondary gasification unit, the hot semi-coke inlet of the secondary gasification unit is located on the side wall of the secondary gasification unit, and the second gasification agent inlet of the secondary gasification unit is located on the side wall of the secondary gasification unit.

[0043] According to another aspect of the present invention, there is provided a staged gasification method, which uses the staged gasification device as described in any one of the foregoing embodiments, and the staged gasification method includes:

[0044] a) Introducing a fuel and a first gasification agent into a primary gasification unit to carry out a gasification reaction to generate a gas-solid mixture;

[0045] b) The gas-solid mixture passes through a separation device to at least partially achieve gas-solid separation to form raw gas and hot semi-coke; and

[0046] c) Feed the raw gas and the hot semicoke into the secondary gasification unit through the mutually separated raw gas inlet and hot semicoke inlet respectively, and react with the second gasifying agent fed into the secondary gasification unit to generate the final gas and bottom slag.

[0047] According to a preferred embodiment of the present invention, the second gasifying agent fed into the secondary gasification unit first reacts with the hot semicoke, and the generated product then reacts with the raw gas.

[0048] According to a preferred embodiment of the present invention, in step c), feed the hot semicoke into the secondary gasification unit through the hot semicoke inlet provided at the top of the secondary gasification unit, feed the second gasifying agent into the secondary gasification unit through the second gasifying agent inlet provided at the top of the secondary gasification unit, and feed the raw gas into the secondary gasification unit through the raw gas inlet provided on the side wall of the secondary gasification unit.

[0049] According to a preferred embodiment of the present invention, the jet direction of the gasifying agent at the second gasifying agent inlet fed into the secondary gasification unit forms an angle less than 90 degrees with the side wall of the secondary gasification unit.

[0050] According to a preferred embodiment of the present invention, the mass of the solid carried in the hot semicoke is 70%-95% of the mass of the solid in the gas-solid mixture.

[0051] According to a preferred embodiment of the present invention, the mass of the gas contained in the hot semicoke is less than 20% of the mass of the gas in the gas-solid mixture.

[0052] According to a preferred embodiment of the present invention, in step c), the reaction temperature range between the hot semicoke and the second gasifying agent is t2 - 100°C < T1 < t2 + 500°C, where T1 is the reaction temperature and t2 is the fuel ash softening temperature.

[0053] According to a preferred embodiment of the present invention, the temperature range of the final gas is T2 < t2, where T2 is the temperature range of the final gas and t2 is the fuel ash softening temperature.

[0054] According to a preferred embodiment of the present invention, the first gasifying agent is air or oxygen or a mixture of air, oxygen and steam, or a mixture of two of them.

[0055] According to a preferred embodiment of the present invention, the second gasifying agent is air or oxygen or a mixture of air, oxygen and steam, or a mixture of two of them.

[0056] According to the staged gasification device and the staged gasification method of the present invention, the products generated by the first-stage gasification unit reaction can be separated into raw gas and hot semi-coke, which are respectively introduced into different positions of the second-stage gasification unit, so that the unreacted carbon generated by the first-stage gasification unit is concentrated to react with the second gasifying agent, promoting the conversion of carbon while reducing the reaction between the second gasifying agent and the raw gas, and solving the problem of low gasification performance indicators in the prior art. The hot semi-coke contains a certain amount of gaseous substances, and a certain gas content rate in the hot semi-coke helps the transportation of the hot semi-coke and the rapid formation of a high-temperature zone, and the gas volume ratio is less than 20%, so as to reduce the consumption of the effective gases (such as CH4, CO, H2, etc.) already generated in the first-stage gasification unit, thereby improving the gasification performance of the system. The second gasifying agent first reacts with the hot semi-coke, and the generated product then reacts with the raw gas, which can effectively utilize the gasification sensible heat of the reaction between the hot semi-coke and the gasifying agent, promote the conversion of the carbon in the semi-coke carried in the raw gas and the cracking of tar, improve the gasification performance, reduce the tar in the final gas, and at the same time reduce the temperature of the final gas through the raw gas, reduce the temperature of the second-stage gasification furnace wall surface, thereby reducing the system complexity and cost and improving the system operation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of the staged gasification device according to Embodiment 1 of the present invention;

[0058] Figure 2 Schematic diagram of the staged gasification device according to Embodiment 2 of the present invention;

[0059] Figure 3 For Figure 2 Top view of the annular air box in

[0060] Figure 4 Schematic diagram of the staged gasification device according to Embodiment 3 of the present invention;

[0061] Figure 5 Schematic diagram of the staged gasification device according to Embodiment 4 of the present invention;

[0062] Figure 6 For Figure 5 Top view of the annular air box in

[0063] Figure 7 Schematic diagram of the staged gasification device according to Embodiment 5 of the present invention; and

[0064] Figure 8 Schematic diagram of the staged gasification device according to Embodiment 6 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0065] Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings, where like or similar reference numerals denote like or similar elements. Additionally, in the following detailed description, for the purpose of explanation, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of this disclosure. However, it is obvious that one or more embodiments can be implemented without these specific details. In other instances, well-known structures and devices are illustrated in a schematic manner to simplify the drawings.

[0066] Based on the prior art, the inventors found that in the staged gasification method, after the products generated by the primary gasification unit are separated to form a first gas stream and a second gas stream, and then the first gas stream and the second gas stream are respectively fed into the secondary gasification unit for staged reaction, it is beneficial to improve the gasification efficiency. However, if the semi-coke content ratio of the first gas stream to the second gas stream is too small and a large amount of fly ash exists in the second gas stream, it cannot react with the gasifying agent, which will directly affect the gasification performance of the system, especially when the secondary gasification unit operates under the condition of solid slag discharge.

[0067] Before the products generated by the primary gasification unit enter the secondary gasification unit, the gas-solid separation efficiency is low, resulting in a large amount of fly ash existing in the second gas stream, which cannot react with the gasifying agent or pass through the high-temperature reaction zone, directly affecting the gasification performance of the system. Especially when the secondary gasification unit operates under the condition of solid slag discharge, the impact is significant. In order to fully convert the carbon in the semi-coke generated by the primary gasification unit, it is often necessary to create a high-temperature environment in the secondary gasification unit, which will greatly increase the cost of the equipment and the complexity of the subsequent system.

[0068] Therefore, the present invention provides a new staged gasification device and a staged gasification method.

[0069] According to the general concept of the present invention, a staged gasification device is provided. The staged gasification device includes: a primary gasification unit; a separation device disposed downstream of the primary gasification unit and communicating with the primary gasification unit; and a secondary gasification unit disposed downstream of the separation device and communicating with the separation device. Wherein, the separation device is configured to at least partially achieve gas-solid separation of the products of the primary gasification unit to form raw gas and hot semi-coke, and wherein the secondary gasification unit includes a raw gas inlet and a hot semi-coke inlet that are separated from each other.

[0070] Embodiment 1

[0071] Figure 1 It is a schematic diagram of the staged gasification device according to Embodiment 1 of the present invention, as Figure 1As shown in the figure, the staged gasification device includes: a primary gasification unit 1; a separation device 2 disposed downstream of the primary gasification unit 1 and communicating with the primary gasification unit 1; and a secondary gasification unit 3 disposed downstream of the separation device 2 and communicating with the separation device 2. Wherein, the separation device 2 is configured to at least partially achieve gas-solid separation of the products of the primary gasification unit 1 to form raw gas E and hot semi-coke D, and wherein the secondary gasification unit 3 includes a raw gas inlet and a hot semi-coke inlet that are separated from each other.

[0072] The primary gasification unit 1 includes a fuel inlet, a first gasifying agent inlet, and a gas-solid mixture outlet; the separation device 2 includes a material inlet, a raw gas outlet, and a hot semi-coke outlet; the secondary gasification unit 3 includes a secondary gasification furnace chamber 33, on which the raw gas inlet, the hot semi-coke inlet, a second gasifying agent inlet, a final gas outlet, and a bottom slag outlet are provided. Wherein, the gas-solid mixture outlet of the primary gasification unit 1 is communicated with the material inlet of the separation device 2, the raw gas outlet of the separation device 2 is communicated with the raw gas inlet of the secondary gasification unit 3, and the hot semi-coke outlet of the separation device 2 is communicated with the hot semi-coke inlet of the secondary gasification unit 3. The primary gasification unit 1, the separation device 2, and the secondary gasification unit 3 are interconnected. The separation device 2 is an efficient separation device, and the separation efficiency of the gas-solid mixture C generated by the primary gasification unit 1 is greater than 70%, and the solid material outlet contains a certain amount of gas, and the mass of the gas is less than 20% of the mass of the gas in the gas-solid mixture C.

[0073] Advantageously, in Figure 1 In the embodiment of, in the flow direction of the gasifying agent in the secondary gasification unit 3, the hot semi-coke inlet is provided upstream of the raw gas inlet. Specifically, the hot semi-coke inlet of the secondary gasification unit 3 is located at the top of the secondary gasification unit 3, the second gasifying agent inlet of the secondary gasification unit 3 is located at the top of the secondary gasification unit 3, and the raw gas inlet of the secondary gasification unit 3 is located on the side wall of the secondary gasification unit 3.

[0074] According to this embodiment, the staged gasification method includes: a) introducing a fuel B (taking coal as an example) and a first gasifying agent A into the primary gasification unit 1 to carry out a gasification reaction to generate a gas-solid mixture C; b) the gas-solid mixture C passes through the separation device 2 to at least partially achieve gas-solid separation to form raw gas E and hot semi-coke D; and c) respectively introducing the raw gas E and the hot semi-coke D into the secondary gasification unit 3 through the separated raw gas inlet and hot semi-coke inlet to react with the second gasifying agent F introduced into the secondary gasification unit 2 to generate a final gas G and a bottom slag H.

[0075] Advantageously, the second gasifying agent F introduced into the secondary gasification unit 2 first reacts with the hot semicoke D, and the resulting product then reacts with the raw gas E to form the final gas G and the bottom slag H, which leave the secondary gasification unit 3. Specifically, in step c), the hot semicoke D is introduced into the secondary gasification unit 3 through the hot semicoke inlet provided at the top of the secondary gasification unit 3, the second gasifying agent F is introduced into the secondary gasification unit 3 through the second gasifying agent inlet provided at the top of the secondary gasification unit 3, and the raw gas E is introduced into the secondary gasification unit 3 through the raw gas inlet provided on the side wall of the secondary gasification unit 3.

[0076] In a preferred embodiment, the jet direction of the second gasifying agent inlet of the second gasifying agent F introduced into the secondary gasification unit 3 forms an angle β less than 90 degrees with the side wall of the secondary gasification unit 3.

[0077] According to a preferred embodiment of the present invention, the solid mass carried in the hot semicoke D is 70%-95% of the solid mass in the gas-solid mixture C, so that the unreacted carbon carried by the gas-solid mixture C generated by the primary gasification unit 1 is concentrated to react with the second gasifying agent F, promoting the conversion of carbon.

[0078] According to a preferred embodiment of the present invention, the gas mass contained in the hot semicoke D is less than 20% of the gas mass in the gas-solid mixture C. On the one hand, the hot semicoke D contains gas, which helps the transportation of the hot semicoke and enables a rapid reaction with the second gasifying agent F (the combustible gas contained in this gas can rapidly undergo a combustion reaction with the gasifying agent), forming a high-temperature zone; on the other hand, the gas volume ratio is less than 20%, so as to reduce the proportion of the oxidation reaction between the second gasifying agent F and the combustible gases (such as CH4, CO, H2, etc.) in the gas-solid mixture C, and increase the reaction proportion of the second gasifying agent F with carbon, thereby improving the gasification performance of the system.

[0079] In step c), the reaction temperature range between the hot semicoke D and the second gasifying agent F is t2 - 100°C < T1 < t2 + 500°C, where T1 is the reaction temperature and t2 is the fuel ash softening temperature, and the high-temperature reaction promotes the conversion of carbon in the hot semicoke D.

[0080] The temperature range of the final gas G is T2 < t2, where T2 is the temperature range of the final gas G and t2 is the fuel ash softening temperature. The reaction product of the second gasifying agent F and the hot semicoke D has a high temperature, while the raw gas E has a relatively low temperature. After the two are mixed, heat exchange occurs, as well as endothermic reactions such as C + CO2 → CO, C + H2O → CO + H2, methane decomposition, and tar cracking. While further strengthening carbon conversion and reducing the tar content in the final gas, the temperature T2 of the final gas G at the outlet of the secondary gasification unit 3 is reduced, realizing solid slag discharge and reducing the system complexity and cost.

[0081] According to a preferred embodiment of the present invention, the first gasifier A is air or oxygen or a mixture of air, oxygen and steam, or a mixture of two of them; and / or, the second gasifier F is air or oxygen or a mixture of air, oxygen and steam, or a mixture of two of them.

[0082] In the first embodiment, the distance between the position of the raw gas inlet and the top of the secondary gasification unit 3 is 1 / 3 - 1 / 4 of the total height of the secondary gasification unit 3, and the position of the raw gas inlet is higher than the position of the final gas outlet of the secondary gasification unit 3.

[0083] Furthermore, the central axis of the raw gas inlet can form an angle less than 90 degrees with the side wall of the secondary gasification unit 3. According to a preferred embodiment of the present invention, the separation device 2 is a downward exhaust cyclone separation device, which can effectively reduce the overall height of the system and the construction cost while ensuring the separation efficiency.

[0084] According to a preferred embodiment of the present invention, the number of the raw gas inlets is multiple, and the intersection point of the extension lines of the central axes of the multiple raw gas inlets is not lower than the position of the final gas outlet.

[0085] As Figure 1 shown, the secondary gasification furnace 33 includes two cylindrical sections with unequal diameters. The diameter d1 of the upper cylindrical section is smaller than the diameter d2 of the lower cylindrical section. The hot semi-coke inlet and the second gasifier inlet are arranged at the top of the upper cylindrical section, and the raw gas inlet is arranged on the lower cylindrical section. In this way, on the one hand, the sectional heat load of the reaction zone between the hot semi-coke and the gasifier can be increased, which is beneficial to the formation of the high-temperature zone. On the other hand, the gas flow velocity at the lower part of the furnace is reduced, the residence time of the solid semi-coke brought into the furnace by the raw gas is prolonged, and the gasification reaction is strengthened.

[0086] Embodiment Two

[0087] Figure 2 is a schematic diagram of the staged gasification device according to Embodiment Two of the present invention; Figure 3 is Figure 2 a top view of the annular air box in Figure 2-3 As shown, the staged gasification device further includes an annular air box 32, which is arranged between the raw gas outlet of the separation device 2 and the raw gas inlet of the secondary gasification unit 3 for distributing the raw gas. Specifically, the annular air box 32 is arranged above the lower cylindrical section, and the raw gas inlet is arranged at the top of the lower cylindrical section, so that the raw gas E distributed by the annular air box 32 enters the secondary gasification furnace 33 from the top of the lower cylindrical section.

[0088] Another difference between the second embodiment and the first embodiment is that: the staged gasification device further includes a burner 31, and the burner 31 is arranged at the top of the secondary gasification furnace chamber 33. The burner 31 is arranged at the top of the upper cylindrical section, and the raw gas inlet is arranged at the top of the lower cylindrical section.

[0089] The annular air box 32 is used to redistribute the raw gas E from the separation device 2, and the raw gas E enters the secondary gasification furnace chamber 33 in multiple paths and approaches the wall surface of the secondary gasification furnace chamber 33. Through uniform distribution, the relatively low-temperature raw gas E surrounds the outside of the high-temperature zone formed by the reaction of the second gasifying agent F and the hot semi-coke D, reducing the heat radiation of the high-temperature zone to the furnace wall surface, lowering the furnace wall surface temperature, thereby protecting the furnace wall surface and reducing the furnace construction cost. Among them, the burner 31 is located at the top of the furnace of the upper cylindrical section (with a diameter of d1) of the secondary gasification furnace chamber 33, and the raw gas inlet is located at the top of the furnace of the upper cylindrical section (with a diameter of d2) of the secondary gasification furnace chamber 33, and the position of the raw gas inlet is upstream of the final gas outlet.

[0090] The raw gas E first enters the annular air box 32, and then forms the raw gas E after being redistributed by the annular air box. The raw gas E enters the secondary gasification furnace chamber 33 in multiple paths, so that the relatively low-temperature raw gas E surrounds the outside of the high-temperature zone formed by the reaction of the second gasifying agent F and the hot semi-coke D, reducing the heat radiation of the high-temperature zone to the furnace wall surface, lowering the furnace wall surface temperature, thereby protecting the furnace wall surface and reducing the furnace construction cost. The raw gas E formed after being redistributed by the annular air box 32 enters the secondary gasification furnace chamber 33 from the top of the furnace with a diameter of d2, so that the position where the raw gas E enters the furnace chamber 33 is lower than the position where the second gasifying agent F and the hot semi-coke D enter the furnace chamber 33, avoiding premature contact and oxidation reaction between the combustible gas in the raw gas E and the second gasifying agent F.

[0091] As a further preferred solution, the included angle between the central axis of the raw gas inlet and the top wall of the secondary gasification furnace chamber 33 satisfies: 90° ≤ d ≤ 135°.

[0092] Embodiment Three

[0093] Figure 4 It is a schematic diagram of the staged gasification device according to the third embodiment of the present invention. As Figure 4 shown, the annular air box 32 is arranged on the outer periphery of the lower cylindrical section, and the raw gas inlet is arranged on the side wall of the lower cylindrical section, so that the raw gas E after being distributed by the annular air box 32 enters the secondary gasification furnace chamber 33 from the side wall of the lower cylindrical section. Preferably, the included angle between the central axis of the raw gas inlet and the side wall of the secondary gasification furnace chamber 33 satisfies: 0° < δ ≤ 90°.

[0094] The difference between the third embodiment and the second embodiment is that the raw gas E formed after being redistributed by the annular air box 32 enters the secondary gasification furnace chamber 33 from the furnace chamber side wall with a diameter of d2, thereby expanding the high-temperature reaction zone between the hot semi-coke D and the second gasifying agent F and enabling the hot semi-coke to fully react. Among them, the intersection point of the extension lines of the central axes of multiple raw gas inlets is not lower than the position of the final gas outlet.

[0095] Embodiment Four

[0096] Figure 5 It is a schematic diagram of the staged gasification device according to Embodiment Four of the present invention; Figure 6 It is Figure 5 the top view of the annular air box in Figure 5-6 As shown, the annular air box 32 includes an annular slit, and the raw gas E distributed by the annular air box 32 vertically enters the secondary gasification furnace chamber 33 along the annular slit.

[0097] The difference between the fourth embodiment and the second embodiment is that the raw gas outlet of the annular air box 32 is of an annular slit structure, and the raw gas formed after distribution vertically enters the secondary gasification furnace chamber 33 evenly along the annular slit, playing a better role in protecting the furnace wall surface.

[0098] Embodiment Five

[0099] Figure 7 It is a schematic diagram of the staged gasification device according to Embodiment Five of the present invention, as Figure 7 shown. The secondary gasification furnace chamber 33 includes a partition plate 34, and the partition plate 34 divides the secondary gasification furnace chamber 33 into a central area and a heat insulation area surrounding the central area. The raw gas E introduced into the secondary gasification furnace chamber 33 through the raw gas inlet enters the heat insulation area, and the second gasifying agent F introduced into the secondary gasification furnace chamber 33 through the second gasifying agent inlet and the hot semi-coke D introduced into the secondary gasification furnace chamber 33 through the hot semi-coke inlet enter the central area.

[0100] The difference between the fifth embodiment and the first embodiment is that in the secondary gasification furnace chamber 33, an independent heat insulation area and a central area are separated by an annular partition plate 34. The heat insulation area is located near the wall surface of the secondary gasification furnace chamber 33 and is arranged around the central area. The raw gas E enters the heat insulation area, and the second gasifying agent F and the hot semi-coke D enter the central area to react. There can be heat conduction between the two areas but no mass transfer, so as to protect the wall surface of the secondary gasification furnace chamber 33 by the raw gas E while the second gasifying agent F does not react with the combustible gas in the raw gas E. The products generated by the reaction in the central area and the raw gas E converge in the lower space of the secondary gasification furnace chamber 33.

[0101] Embodiment Six

[0102] Figure 8 It is a schematic diagram of the staged gasification device according to Embodiment Six of the present invention, as Figure 8As shown in the figure, the staged gasification device includes a burner 31, which is located on the side wall of the secondary gasification furnace chamber 33, and the position of the burner 31 is higher than that of the final coal gas outlet; the number of the burners 31 is multiple, and the multiple burners 31 are circumferentially arranged evenly; the raw coal gas inlet of the secondary gasification unit 3 is located at the top of the secondary gasification unit 3, the hot semi-coke inlet of the secondary gasification unit 3 is located on the side wall of the secondary gasification unit 3, and the second gasifying agent inlet of the secondary gasification unit 3 is located on the side wall of the secondary gasification unit 3; the separation device 2 is a horizontal separation device.

[0103] The difference between Example 6 and Example 2 lies in that: the separation device 2 is a horizontal separation device, which further reduces the overall height of the system; the burner 31 is located on the side wall of the secondary gasification furnace chamber 33, and its position is higher than that of the final coal gas G outlet; the number of burners 31 is 2 - 20, and they are circumferentially arranged evenly; in this way, the raw coal gas E enters the furnace chamber along the axial direction from the top of the secondary gasification furnace chamber 33, and the raw coal gas E directly passes through the high-temperature zone formed by the reaction of the hot semi-coke D and the second gasifying agent F, which can promote the reaction of the carbon carried therein to the greatest extent and promote the cracking of the tar carried therein.

[0104] According to the staged gasification device and the staged gasification method of the present invention, the products generated by the primary gasification unit reaction can be separated into raw coal gas and hot semi-coke, which are respectively introduced into different positions of the secondary gasification unit, so that the unreacted carbon generated by the primary gasification unit is concentrated to react with the second gasifying agent, promoting the conversion of carbon, and at the same time avoiding the problems of unstable operation of the existing technology equipment and low gasification performance indicators. There are certain gaseous substances in the hot semi-coke, and a certain gas content rate in the hot semi-coke helps the transportation of the hot semi-coke and the rapid formation of a high-temperature zone, and the gas volume ratio is less than 20%, so as to reduce the consumption of the generated effective gases (such as CH4, CO, H2, etc.), thereby improving the gasification performance of the system. While effectively utilizing the gasification sensible heat of the reaction between the hot semi-coke and the gasifying agent to improve the gasification performance and reduce the tar in the final coal gas, the temperature of the final coal gas is reduced by the raw coal gas, and the temperature of the secondary gasification furnace chamber wall is reduced, thereby reducing the system complexity and cost and improving the system operation stability.

[0105] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that these embodiments can be changed without departing from the principle and spirit of the present invention. The scope of application of the present invention is defined by the appended claims and their equivalents.

[0106] List of reference numerals:

[0107] 1 Primary gasification unit

[0108] 2 Separation device

[0109] 3 Secondary gasification unit

[0110] 31 Burner

[0111] 32 Annular air box

[0112] 33 Secondary gasification furnace chamber

[0113] 34 Baffle plate

[0114] A Primary gasifying agent

[0115] B Fuel

[0116] C Gas-solid mixture

[0117] D Hot semi-coke

[0118] E Raw gas

[0119] F Secondary gasifying agent

[0120] G Final gas

[0121] H Bottom slag.

Claims

1. A staged gasification device, characterized in that, The staged gasification device includes: A primary gasification unit (1); A separation device (2), which is arranged downstream of the primary gasification unit (1) and is in communication with the primary gasification unit (1). Wherein, the separation device (2) is configured to at least partially achieve gas-solid separation of the products of the primary gasification unit (1) to form raw gas (E) and hot semi-coke (D); A secondary gasification unit (3), which is arranged downstream of the separation device (2) and is in communication with the separation device (2). Wherein, the secondary gasification unit (3) includes a secondary gasification furnace chamber (33); The secondary gasification furnace chamber (33) is provided with a raw gas inlet, a hot semi-coke inlet, a second gasifying agent inlet, and a final gas outlet. Wherein, the raw gas inlet is located at the top of the secondary gasification furnace chamber (33), the hot semi-coke inlet is located on the side wall of the secondary gasification furnace chamber (33), and the second gasifying agent inlet is located on the side wall of the secondary gasification furnace chamber (33); A burner (31), which is located on the side wall of the secondary gasification furnace chamber (33), and the position of the burner (31) is higher than the position of the final gas outlet; and An annular air box (32), which is arranged between the raw gas outlet of the separation device (2) and the raw gas inlet, and is used for distributing the raw gas (E). The raw gas (E) enters the furnace chamber along the axial direction from the top of the secondary gasification furnace chamber (33) and directly passes through the high-temperature zone formed by the reaction of the hot semi-coke (D) and the second gasifying agent (F); Wherein, the separation device (2) includes a horizontal separation device.

2. The staged gasification device according to claim 1, characterized in that: The primary gasification unit (1) includes a fuel inlet, a first gasifying agent inlet, and a gas-solid mixture outlet; The separation device (2) includes a material inlet, a raw gas outlet, and a hot semi-coke outlet; Wherein, the gas-solid mixture outlet is in communication with the material inlet, the raw gas outlet is in communication with the raw gas inlet, and the hot semi-coke outlet is in communication with the hot semi-coke inlet; The secondary gasification furnace chamber (33) is further provided with a bottom slag outlet.

3. The staged gasification device according to claim 1, characterized in that: The number of the burners (31) includes a plurality, and the plurality of burners (31) are circumferentially and evenly arranged.

4. A staged gasification method, using the staged gasification device according to any one of claims 1 - 3, characterized in that, The staged gasification method includes: a) Introducing fuel (B) and a first gasifying agent (A) into the primary gasification unit (1) to carry out a gasification reaction to generate a gas-solid mixture (C); b) The gas-solid mixture (C) passes through the separation device (2) to at least partially achieve gas-solid separation to form raw gas (E) and hot semi-coke (D); and c) Respectively introducing the raw gas (E) and the hot semi-coke (D) into the secondary gasification furnace chamber (33) through the mutually separated raw gas inlet and hot semi-coke inlet, and reacting with the second gasifying agent (F) introduced into the secondary gasification furnace chamber (33) to generate final gas (G) and bottom slag (H); Wherein, the raw gas (E) enters the furnace chamber along the axial direction from the top of the secondary gasification furnace chamber (33) and directly passes through the high-temperature zone formed by the hot semi-coke (D) and the second gasifying agent (F).

5. The staged gasification method according to claim 4, characterized in that: The mass of the solids carried in the hot semi-coke (D) is 70% - 95% of the mass of the solids in the gas-solid mixture (C).

6. The staged gasification method according to claim 4, characterized in that: The mass of the gas contained in the hot semi-coke (D) is less than 20% of the mass of the gas in the gas-solid mixture (C).

7. The staged gasification method according to claim 4, characterized in that: In step c), the reaction temperature range between the hot semi-coke (D) and the second gasifying agent (F) is t2 - 100°C < T1 < t2 + 500°C, where T1 is the reaction temperature and t2 is the fuel ash softening temperature.

8. The staged gasification method according to claim 4, characterized in that: The temperature range of the final coal gas (G) is T2 < t2, where T2 is the temperature range of the final coal gas (G) and t2 is the fuel ash softening temperature.

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