A device, method and system for improving tail gas quality during activated coke preparation

Abstract

The present invention discloses a device, method and system for improving the quality of tail gas during the preparation of activated coke. The device includes a steam generator, a first CO2 absorption section, a reforming section, a heat exchanger, and a second CO2 absorption section. The first tail gas inlet of the first CO2 absorption section is communicated with the outlet of the first heat release side of the steam generator; the first steam inlet of the reforming section is communicated with the outlet of the first heat absorption side of the steam generator, and the second tail gas inlet of the reforming section is communicated with the first tail gas outlet of the first CO2 absorption section; the second heat release side inlet of the heat exchanger is communicated with the second tail gas outlet of the reforming section, and the second heat absorption side outlet of the heat exchanger is communicated with the first heat absorption side inlet of the steam generator; the third tail gas inlet of the second CO2 absorption section is communicated with the outlet of the second heat release side of the heat exchanger. The device of the present invention can improve the pyrolysis gas conversion rate and reforming efficiency, greatly increase the H2 content, reduce the CO2 output, improve the quality of pyrolysis gas, reduce the tar output, and promote carbon emission reduction.

Description

Technical Field

[0001] The present invention relates to the field of activated coke preparation, and in particular to a device, method and system for improving the quality of tail gas in the process of activated coke preparation. Background Art

[0002] The one-step coke oven is divided into a carbonization section and an activation section, which successively carry out carbonization and activation of the raw materials. The carbonization is carried out under air-tight conditions, and the volatiles in the raw materials are analyzed out by heating and converted into carbonized materials. Water vapor is introduced into the carbonized material in the activation furnace as an activation medium, and an activation reaction occurs with the carbonized material to generate activated carbon or activated coke. Therefore, the reaction of the raw material in the carbonization section is a pyrolysis reaction, which is manifested as the continuous loss of solids and the generation of a large amount of gas and tar. The tar exists in the form of gas at high temperature. The temperature required in the activation section is higher than that in the carbonization section, so as to achieve the reaction conditions between fixed carbon and water vapor. Therefore, the activation section involves not only the water vapor gasification reaction of the carbonized material, but also the further precipitation of volatiles inside the carbonized material. The reaction at this stage is characterized by the use of H 2 , CO and CO 2 The main components of the gas phase products in the activation stage and carbonization stage are H 2 ,CO,CO 2 , CH 4 , H 2 O and tar and other macromolecular substances.

[0003] In order to improve the quality of pyrolysis tail gas, high-temperature catalytic reforming in the reforming furnace is generally used to promote the secondary cracking of macromolecules and increase H 2 concentration, reducing CO 2 The current reforming process generally uses natural minerals such as dolomite and olivine as catalyst bed materials for the reforming furnace. Among them, calcined dolomite with calcium oxide and magnesium oxide as the main components is mainly used as a catalyst for CO 2 Absorbent, reducing CO in the reforming process 2 concentration, thus affecting the reaction balance; catalysts such as olivine with iron oxide as the main active ingredient rely on the catalytic cracking of iron oxide and the catalytic effect on the water gas reaction to promote the improvement of pyrolysis gas components. 2 The required temperature of the absorbent is much lower than that of gas reforming, and it is difficult to further affect the conversion rate of other components in the pyrolysis gas. During the reforming process, as the water gas reaction and reforming reaction proceed, CO 2The continuous increase in concentration is not only not conducive to the reaction process, but also increases the carbon emissions of the system. Reforming furnaces generally use external heating, which leads to high surface temperature of the catalyst bed in the furnace, low internal temperature, uneven temperature distribution, and low catalytic efficiency. Therefore, it is of great significance to improve the reforming furnace of pyrolysis gas and improve the quality of pyrolysis gas. Summary of the invention

[0004] The present invention is based on the inventor's discovery and understanding of the following facts and problems: In the current pyrolysis gas reforming process, CO 2 The temperature range required by the absorbent is inconsistent with the temperature range required for pyrolysis gas reforming. The single catalyst used is difficult to balance the improvement of pyrolysis gas conversion rate and the promotion of carbon emission reduction. The heating method of the external heating reformer makes the catalyst bed material temperature uneven and the catalytic efficiency low. Therefore, selecting appropriate bed materials for the tail gas upgrading device and rationally planning the regional temperature of the tail gas upgrading device and the distribution of catalysts and absorbents have an important impact on improving the quality of pyrolysis gas, promoting carbon emission reduction, and improving the pyrolysis gas conversion rate.

[0005] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiment of the present invention provides a device, method and system for upgrading the tail gas in the process of preparing activated coke, the device for upgrading the tail gas comprises a steam generator, a first CO 2 Absorption section, reforming section, heat exchanger and second CO 2 The absorption section can improve the conversion rate and reforming efficiency of pyrolysis tail gas, and greatly increase the H 2 content, reducing CO 2 output, improve the quality of pyrolysis gas, reduce tar output and promote carbon emission reduction.

[0006] A device for improving the quality of tail gas in an activated coke preparation process according to an embodiment of the present invention comprises:

[0007] A steam generator, wherein the steam generator has a first heat release channel and a first heat absorption channel, wherein the first heat release channel is provided with a first heat release side inlet and a first heat release side outlet, wherein the first heat release side inlet is used to communicate with an exhaust gas outlet of a coke oven, and the first heat absorption channel is provided with a first heat absorption side inlet and a first heat absorption side outlet, wherein the first heat absorption side outlet is used to communicate with a high-temperature steam inlet of the coke oven;

[0008] First CO 2 The absorption stage, the first CO 2 The absorption section is provided with a first tail gas inlet and a first tail gas outlet, and the first tail gas inlet is connected to the first heat release side outlet;

[0009] A reforming section, wherein the reforming section is provided with a first steam inlet, a second tail gas inlet, and a second tail gas outlet, wherein the first steam inlet is communicated with the first heat absorption side outlet, and the second tail gas inlet is communicated with the first tail gas outlet;

[0010] A heat exchanger, wherein the heat exchanger has a second heat release channel and a second heat absorption channel, the second heat release channel is provided with a second heat release side inlet and a second heat release side outlet, the second heat release side inlet is communicated with the second tail gas outlet, the second heat absorption channel is provided with a second heat absorption side inlet and a second heat absorption side outlet, the second heat absorption side inlet is used to communicate with the low-temperature water vapor outlet of the coke oven, and the second heat absorption side outlet is communicated with the first heat absorption side inlet;

[0011] Second CO 2 Absorption stage, the second CO 2 The absorption section is provided with a third tail gas inlet and a third tail gas outlet, and the third tail gas inlet is communicated with the second heat release side outlet.

[0012] Advantages and technical effects of the device for upgrading tail gas in the process of preparing activated coke according to the embodiment of the present invention: the tail gas upgrading device is provided with a first CO 2 Absorption section, reforming section and second CO 2 Absorption stage. First CO 2 The absorption section absorbs CO in the tail gas before the reforming section 2 , reduce the CO in the tail gas entering the reforming section 2 content, thereby affecting the gas phase reaction balance in the tail gas reforming section, improving the CO conversion rate and H 2 The reforming stage adopts steam catalytic reforming process to reduce tar content and increase H 2 Output, improve the quality of pyrolysis gas; the tail gas after reforming is cooled and enters the second CO 2 CO is absorbed again in the absorption section 2 , which can convert the CO produced by the reforming reaction 2 Absorption, reducing CO in tail gas after reforming 2 concentration, improve the quality of gas products. 2 In the absorption section, after reforming, a large amount of CO will still be produced 2 , affecting the quality of pyrolysis gas; if only the second CO 2 In the absorption section, a large amount of CO in the tail gas produced by the coke oven 2 It will hinder the water gasification reaction and water vapor gasification reaction in the reforming section, affecting the quality of the reformed gas. 2 The absorption section can effectively reduce CO 2 concentration, avoid CO 2The concentration continues to increase with the progress of water-gas reaction, reforming reaction, etc., which is not conducive to the progress of the reaction. 2 The setting of the absorption section is beneficial to improving the catalytic efficiency, the pyrolysis gas conversion rate, the reforming efficiency, and greatly increasing the H 2 content, reducing CO 2 output, improve the quality of pyrolysis gas, reduce tar output and promote carbon emission reduction.

[0013] The exhaust gas produced by the coke oven during the coking process is of high temperature, and the first CO 2 The absorption section absorbs CO 2 The required temperature is relatively low, so the tail gas needs to be passed into the steam generator to cool down to the first CO 2 The temperature required for the absorption section, at the same time, in the steam generator, the tail gas releases heat, heating the water vapor flowing out of the heat exchanger to obtain high-temperature water vapor, which can supply the required water vapor to the activation section and reforming section of the coke oven, which is beneficial to the utilization of the waste heat of the tail gas and improves the energy utilization efficiency.

[0014] The heat exchanger cools down the reformed tail gas, which is beneficial to improve the first CO 2 CO in the absorption section 2 Absorbent for CO 2 absorption efficiency; at the same time, the heat exchanger heats the low-temperature water vapor flowing out of the coke oven, which is conducive to fully recovering and utilizing the waste heat of the tail gas and improving the energy utilization efficiency of the process.

[0015] In some embodiments, the reforming section is provided with a microwave heating device for performing microwave heating on the reforming section.

[0016] In some embodiments, the first CO 2 The absorption section is provided with carbide slag;

[0017] And / or, the reforming section is provided with red mud;

[0018] and / or, the second CO 2 The absorption section is provided with carbide slag.

[0019] The embodiment of the present invention provides a method for improving the quality of tail gas in the process of preparing activated coke. The device for improving the quality of tail gas in the process of preparing activated coke implemented by the present invention comprises the following steps:

[0020] (1) The coke oven generates tail gas during the process of preparing activated coke, and the tail gas enters the steam generator for cooling;

[0021] (2) The exhaust gas after cooling by the steam generator enters the first CO 2 Absorption section, absorbs CO in tail gas 2 ;

[0022] (3) Absorption of CO 2 The tail gas after the reaction enters the reforming section, mixes with the steam introduced into the reforming section, and undergoes steam catalytic reforming;

[0023] (4) the tail gas after reforming in the reforming section enters the heat exchanger for cooling;

[0024] (5) The cooled exhaust gas enters the second CO 2 Absorption section, absorbs CO in tail gas 2 , and obtain hydrogen-rich combustible gas.

[0025] In the embodiment of the present invention, the tail gas generated by the coke oven during the coking process has a high temperature and needs to be first introduced into the steam generator for cooling. The cooled tail gas is then introduced into the first CO 2 Absorption of CO in the absorption section 2 The reforming section adopts a steam catalytic reforming process. The reformed tail gas enters the heat exchanger for cooling and then enters the second CO 2 Absorption section, absorbs CO in tail gas again 2 , CO is set before and after the reforming stage 2 The absorption section can effectively reduce CO 2 concentration, to avoid the occurrence of water gas reaction, reforming reaction, etc., CO 2 The concentration continues to increase, which is not conducive to the reaction. It improves the catalytic efficiency, the pyrolysis gas conversion rate, the reforming efficiency, and greatly increases the H 2 content, reducing CO 2 output, improve the quality of pyrolysis gas, reduce tar output and promote carbon emission reduction.

[0026] In some embodiments, the first CO 2 The absorption section uses carbide slag as CO 2 Absorbent;

[0027] And / or, the reforming furnace uses red mud as a catalyst and / or a microwave absorber;

[0028] and / or, the second CO 2 The absorption section uses carbide slag as CO 2 Absorbent.

[0029] In some embodiments, in step (1), the temperature of the tail gas generated by the coke oven is 550°C to 950°C.

[0030] In some embodiments, in step (2), the first CO 2 The temperature of the absorption section is 200℃~500℃.

[0031] In some embodiments, in step (3), the reforming section is assisted by microwave heating;

[0032] and / or, the reforming section is heated by an external heat source;

[0033] and / or, the temperature of the reforming section is 700° C. to 900° C.;

[0034] And / or, the temperature of the water vapor introduced into the reforming section is 450°C to 600°C.

[0035] In some embodiments, in step (5), the second CO 2 The temperature of the absorption section is 100℃~300℃.

[0036] An embodiment of the present invention provides an activated coke preparation system, including a device for upgrading the quality of exhaust gas in the activated coke preparation process of the embodiment of the present invention, and also including a coke oven and a feeding device, the coke oven is provided with a feed port and a high-temperature water vapor inlet, the high-temperature water vapor inlet is connected to the first heat absorption side outlet, the feed port of the coke oven is connected to the feed pipe of the feeding device, the coke oven is also provided with a cooling water coil, the cooling water coil is provided with a cooling water inlet and a low-temperature water vapor outlet, the low-temperature water vapor outlet is connected to the second heat absorption side inlet.

[0037] In an embodiment of the present invention, an activated coke preparation system is also provided. The activated coke preparation system includes a coke oven and a feeding device, which are used to prepare activated coke. The exhaust gas generated by the coke oven enters the exhaust gas upgrading device for upgrading. The activated coke preparation system has all the advantages of the exhaust gas upgrading device in the activated coke preparation process, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of a method for improving the quality of tail gas during the preparation of activated coke in an embodiment of the present invention.

[0039] Reference numerals: silo 1; coke oven 2; cooling water coil 3; discharge pipe 4; conveying device 5; steam generator 6; first CO 2 Absorption section 7; reforming section 8; heat exchanger 9; second CO 2 Absorption section 10. DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0041] An apparatus for improving the quality of tail gas in the process of preparing activated coke according to an embodiment of the present invention comprises: a steam generator 6, a first CO 2Absorption section 7, reforming section 8, heat exchanger 9 and second CO 2 Absorption section 10,

[0042] The steam generator 6 has a first heat release channel and a first heat absorption channel, the first heat release channel is provided with a first heat release side inlet and a first heat release side outlet, the first heat release side inlet is used to connect to the tail gas outlet of the coke oven 2, the first heat absorption channel is provided with a first heat absorption side inlet and a first heat absorption side outlet, the first heat absorption side outlet is used to connect to the high-temperature steam inlet of the coke oven 2;

[0043] The first CO 2 The absorption section 7 is provided with a first tail gas inlet and a first tail gas outlet, and the first tail gas inlet is connected to the first heat release side outlet;

[0044] The reforming section 8 is provided with a first steam inlet, a second tail gas inlet and a second tail gas outlet, the first steam inlet is connected to the first heat absorption side outlet, and the second tail gas inlet is connected to the first tail gas outlet;

[0045] The heat exchanger 9 has a second heat release channel and a second heat absorption channel, the second heat release channel is provided with a second heat release side inlet and a second heat release side outlet, the second heat release side inlet is connected to the second tail gas outlet, the second heat absorption channel is provided with a second heat absorption side inlet and a second heat absorption side outlet, the second heat absorption side inlet is used to connect to the low-temperature water vapor outlet of the coke oven 2, and the second heat absorption side outlet is connected to the first heat absorption side inlet;

[0046] The second CO 2 The absorption section 10 is provided with a third tail gas inlet and a third tail gas outlet, and the third tail gas inlet is communicated with the second heat release side outlet.

[0047] The device for improving the quality of tail gas in the process of preparing activated coke according to the embodiment of the present invention is provided with a first CO 2 Absorption section, reforming section and second CO 2 Absorption stage. First CO 2 The absorption section absorbs CO in the tail gas before the reforming section 2 , reduce the CO in the tail gas entering the reforming section 2 content, thereby affecting the gas phase reaction balance in the tail gas reforming section, increasing the CO conversion rate and H 2 The reforming stage adopts steam catalytic reforming process to reduce tar content and increase H 2 Output, improve the quality of pyrolysis gas; the tail gas after reforming is cooled and enters the second CO 2 CO is absorbed again in the absorption section 2 , which can convert the CO produced by the reforming reaction 2 Absorption, reducing CO in tail gas after reforming2 concentration, improve the quality of gas products. 2 In the absorption section, after reforming, a large amount of CO will still be produced 2 , affecting the quality of pyrolysis gas; if only the second CO 2 In the absorption section, a large amount of CO in the tail gas produced by the coke oven 2 It will hinder the water gasification reaction and water vapor gasification reaction in the reforming section, affecting the quality of the reformed gas. 2 The absorption section can effectively reduce CO 2 concentration, avoid CO 2 The concentration continues to increase with the progress of water-gas reaction, reforming reaction, etc., which is not conducive to the progress of the reaction. 2 The setting of the absorption section is beneficial to improving the catalytic efficiency, the pyrolysis gas conversion rate, the reforming efficiency, and greatly increasing the H 2 content, reducing CO 2 output, improve the quality of pyrolysis gas, reduce tar output and promote carbon emission reduction.

[0048] The exhaust gas produced by the coke oven during the coking process is of high temperature, and the first CO 2 The absorption section absorbs CO 2 The required temperature is relatively low, so the tail gas needs to be passed into the steam generator to cool down to the first CO 2 The temperature required for the absorption section, at the same time, in the steam generator, the tail gas releases heat, heating the water vapor flowing out of the heat exchanger to obtain high-temperature water vapor, which can supply the required water vapor to the activation section and reforming section of the coke oven, which is beneficial to the utilization of the waste heat of the tail gas and improves the energy utilization efficiency.

[0049] The heat exchanger cools down the reformed tail gas, which is beneficial to improve the first CO 2 CO in the absorption section 2 Absorbent for CO 2 absorption efficiency; at the same time, the heat exchanger heats the low-temperature water vapor flowing out of the coke oven, which is conducive to fully recovering and utilizing the waste heat of the tail gas and improving the energy utilization efficiency of the process.

[0050] In some embodiments, the invention further comprises a reforming furnace, wherein the reforming furnace is divided into an upper section and a lower section, the upper section and the lower section are connected, and the upper section is the first CO 2 The absorption section 7 is the lower section of the reforming section 8. In the embodiment of the present invention, the first CO 2 The absorption section and the reforming section are designed as an integrated unit and are both arranged in the reforming furnace. The cooled tail gas is introduced into the first CO 2 The absorption section absorbs CO 2 After that, it directly enters the reforming section for reforming.

[0051] In some embodiments, the first CO 2 The absorption section 7 and the reforming section 8 may also be of split design.

[0052] In some embodiments, the reforming section 8 is provided with a microwave heating device for performing microwave heating on the reforming section 8. In the embodiments of the present invention, microwave-assisted heating belongs to an internal heating method, which has the characteristics of high heating rate and fast temperature rise. The material layer of the reforming section is heated by microwaves, and the microwave absorber is heated from the inside after absorbing the microwaves, and the temperature field distribution is high inside and low outside; the material layer of the reforming section is heated by an external heat source, and the temperature field distribution of the material layer is high outside and low inside. The synergistic heating of the external heat source and microwaves makes the temperature field of the material layer uniform, ensures the reforming reaction efficiency, and improves the quality of the pyrolysis gas. In addition, under microwave-assisted catalytic reforming, the catalytic ability of the iron oxide in the red mud catalyst is enhanced, which improves the reaction activity of the tail gas on the catalyst surface. The reforming section uses the synergistic effect of external heat and microwave heating to provide heat for the reforming section. The external heat heats from the outside to the inside and the microwave heats from the inside to the outside. The synergistic effect of the two makes the temperature of the reforming section uniform, quickly increases the temperature of the reforming section, maintains the temperature uniformity, improves the catalytic reforming efficiency, improves the pyrolysis gas conversion rate, and reduces CO 2 Output and promote carbon emission reduction.

[0053] In some embodiments, the first CO 2 The absorption section 7 is provided with carbide slag, which serves as a CO 2 Absorbent;

[0054] And / or, the reforming section 8 is provided with red mud, and the red mud serves as a catalyst and / or a microwave absorber;

[0055] and / or, the second CO 2 The absorption section 10 is provided with carbide slag, which serves as a CO 2 Absorbent.

[0056] In the embodiment of the present invention, CO 2 The absorption section uses carbide slag as CO 2 Absorbent, carbide slag with Ca(OH) 2 As the main component, it can effectively reduce the CO in the pyrolysis tail gas 2 The concentration is conducive to the reforming reaction. The reforming stage uses red mud as a catalyst. 2 O 3 and Al 2 O 3 As the main component, it can effectively promote the steam gasification reaction as a catalyst, thereby reducing the tar content in the tail gas and increasing H 2 content, effectively promoting the water gasification reaction and methane reforming reaction, greatly increasing the H2 content; red mud can also be used as a microwave absorber for internal heating. At the same time, under microwave-assisted catalysis, the catalytic ability of iron oxides is enhanced, which increases the reaction activity of tail gas on the catalyst surface and greatly improves the microwave-assisted catalytic effect. 2 O 3 with Fe 2 O 3 Combined with the Al in red mud 2 O 3 Substances such as Fe 2 O 3 The catalytic activity of Fe 2 O 3 The catalytic capacity and circulation characteristics of red mud are: red mud has the ability to catalyze tar cracking, promote steam gasification reaction, water-gas reaction, etc., which can significantly reduce the tar content in tail gas and greatly increase H 2 content, thereby improving the quality of combustible gas. 2 Absorbents and reforming catalysts can improve reforming efficiency and promote carbon emission reduction. Using carbide slag and red mud as bed materials for upgrading equipment is conducive to the resource utilization of industrial solid waste and reduces the overall cost of the process.

[0057] In some embodiments, a cooler is also included, the cooler having a third heat release channel and a third heat absorption channel, the third heat release channel is provided with a third heat release side inlet and a third heat release side outlet, and the third heat release side inlet of the cooler is connected to the third exhaust gas outlet.

[0058] The embodiment of the present invention provides a method for improving the quality of tail gas in the process of preparing activated coke. The device for improving the quality of tail gas in the process of preparing activated coke implemented by the present invention comprises the following steps:

[0059] (1) The coke oven 2 generates tail gas during the process of preparing activated coke, and the tail gas enters the steam generator 6 for cooling;

[0060] (2) The exhaust gas after cooling by the steam generator 6 enters the first CO 2 Absorption section 7, absorbs CO in tail gas 2 ;

[0061] (3) Absorption of CO 2 The tail gas after the reaction enters the reforming section 8, mixes with the steam introduced into the reforming section 8, and undergoes steam catalytic reforming;

[0062] (4) The tail gas reformed by the reforming section 8 enters the heat exchanger 9 for cooling;

[0063] (5) The cooled exhaust gas enters the second CO 2Absorption section 10, absorbs CO in tail gas 2 , and obtain hydrogen-rich combustible gas.

[0064] In the embodiment of the present invention, the tail gas generated by the coke oven during the coking process has a high temperature and needs to be first introduced into the steam generator for cooling. The cooled tail gas is then introduced into the first CO 2 Absorption of CO in the absorption section 2 The reforming section adopts a steam catalytic reforming process. The reformed tail gas enters the heat exchanger for cooling and then enters the second CO 2 Absorption section, absorbs CO in tail gas again 2 , CO is set before and after the reforming stage 2 The absorption section can effectively reduce CO 2 concentration, to avoid the occurrence of water gas reaction, reforming reaction, etc., CO 2 The concentration continues to increase, which is not conducive to the reaction. It improves the catalytic efficiency, the pyrolysis gas conversion rate, the reforming efficiency, and greatly increases the H 2 content, reducing CO 2 output, improve the quality of pyrolysis gas, reduce tar output and promote carbon emission reduction.

[0065] In some embodiments, the first CO 2 Absorption stage 7 uses carbide slag as CO 2 Absorbent;

[0066] And / or, the reforming section 8 uses red mud as a catalyst and / or a microwave absorber;

[0067] and / or, the second CO 2 The absorption section 10 uses carbide slag as CO 2 Absorbent.

[0068] In some embodiments, in step (1), the tail gas generated by the coke oven 2 includes CO, CO 2 , CH 4 , H 2 and tar; the temperature of the tail gas generated by the coke oven 2 is 550°C to 950°C, specifically, for example, 550°C, 650°C, 750°C, 850°C, 950°C. In the embodiment of the present invention, the tail gas temperature generated by the coke oven is high, and the CO 2 The required temperature is relatively low, so the high-temperature tail gas cannot be directly introduced into the first CO 2 Absorption section.

[0069] In some embodiments, in step (2), the first CO 2The temperature of the absorption section 7 is 200°C to 500°C, specifically, for example, 200°C, 300°C, 400°C, 450°C, 500°C.

[0070] In the embodiment of the present invention, it is further preferred that the first CO 2 The temperature of the absorption section is conducive to increasing the reaction rate while ensuring the feasibility of the reaction. 2 When the temperature of the absorption section is too high, CO 2 The reactions involved in absorption are difficult to achieve; when the temperature is too low, CO 2 The absorption reaction rate is low.

[0071] In some embodiments, in step (3), the reforming section 8 is assisted by microwave heating;

[0072] And / or, the reforming section 8 is heated by an external heat source; optionally, the external heat source includes at least one of a combustion chamber of tail gas, natural gas or coal;

[0073] and / or, the temperature of the reforming section 8 is 700° C. to 900° C., specifically, for example, 700° C., 800° C., 900° C.;

[0074] And / or, the temperature of the water vapor introduced into the reforming section 8 is 450°C to 600°C, specifically, for example, 450°C, 500°C, 550°C, 600°C.

[0075] In the embodiment of the present invention, the water vapor gasification reaction in the reformer: the water vapor reacts with the tar in the tail gas to promote the gasification of the carbon element in the tar to generate CO, CO 2 and H 2 , thereby reducing the tar content in the exhaust gas and increasing H 2 Output; and water gasification reaction: CO is generated by the reaction of water vapor and CO 2 and H 2 , promoting the conversion of CO to H 2 , effectively improve the H 2 content and improve the quality of pyrolysis gas.

[0076] In the embodiment of the present invention, the external heat source and microwave synergistic heating make the temperature field of the material layer uniform, ensure the reforming reaction efficiency, and improve the quality of the pyrolysis gas. In addition, under microwave-assisted catalytic reforming, the catalytic ability of the iron oxide in the catalyst is enhanced, which improves the reaction activity of the tail gas on the catalyst surface. The reforming section adopts the synergistic effect of external heat and microwave heating to provide heat for the reforming section. The external heat heats from the outside to the inside and the microwave heats from the inside to the outside. The synergistic effect of the two makes the temperature of the reforming section uniform, quickly increases the temperature of the reforming section, maintains temperature uniformity, improves the catalytic reforming efficiency, improves the pyrolysis gas conversion rate, and reduces CO2 Output and promote carbon emission reduction.

[0077] In some embodiments, in step (3), the water vapor introduced into the reforming section 8 is mixed with the absorbed CO 2 The exhaust gas H 2 The O / C ratio is 3 to 10:1, specifically, for example, 3:1, 5:1, 7:1, 9:1, 10:1. In the embodiment of the present invention, by optimizing the ratio of tail gas to water vapor in the reforming stage, it is beneficial to promote the shift of reaction equilibrium, increase the reaction rate, and reduce the time required for the reaction. When the tail gas ratio is too high, the reaction rate is slow and the CO conversion rate is low; when the tail gas ratio is too low, the energy consumption required for heating is too high.

[0078] In some embodiments, in step (5), the second CO 2 The temperature of the absorption section 10 is 100°C to 300°C, specifically, for example, 100°C, 150°C, 200°C, 300°C. In the embodiment of the present invention, it is further preferred that the second CO 2 The temperature of the absorption section is conducive to further reducing CO 2 The tail gas from the reforming section is cooled to ensure that the gas temperature is reduced to CO 2 The reaction temperature required for absorption. 2 When the temperature of the absorption section is too high, the subsequent heat exchange intensity required to reduce the temperature of the gas product is higher, and CO 2 The reactions involved in absorption are difficult to achieve; when the temperature is too low, CO 2 The absorption efficiency is low.

[0079] In some embodiments, the second CO 2 The tail gas flowing out of the absorption section 10 is subjected to a cooling treatment, and optionally, a cooler is used for the cooling treatment.

[0080] An embodiment of the present invention provides an activated coke preparation system, including a device for upgrading the quality of exhaust gas in the activated coke preparation process of the embodiment of the present invention, and also including a coke oven 2 and a feeding device, the coke oven 2 is provided with a feed port and a high-temperature water vapor inlet, the high-temperature water vapor inlet is connected to the first heat absorption side outlet, the feed port of the coke oven 2 is connected to the feed pipe of the feeding device, the coke oven 2 is also provided with a cooling water coil 3, the cooling water coil 3 is provided with a cooling water inlet and a low-temperature water vapor outlet, the low-temperature water vapor outlet is connected to the second heat absorption side inlet.

[0081] In an embodiment of the present invention, an activated coke preparation system is also provided. The activated coke preparation system includes a coke oven and a feeding device, which are used to prepare activated coke. The exhaust gas generated by the coke oven enters the exhaust gas upgrading device for upgrading. The activated coke preparation system has all the advantages of the exhaust gas upgrading device in the activated coke preparation process, which will not be repeated here.

[0082] In some embodiments, a discharge device is also included, and a discharge pipe of the discharge device is connected to the discharge port of the coke oven 2.

[0083] In some embodiments, the coke making oven 2 includes two parts, a carbonization part and an activation part. An integrated carbonization and activation furnace or a split design may be adopted; if a split design is adopted, the carbonization furnace may adopt a vertical furnace or a rotary furnace structure, and the activation furnace may adopt a slep furnace, a rake furnace, a vertical furnace or a rotary furnace structure.

[0084] In some embodiments, the lower part of the coke oven 2 is a cooling section for cooling the active coke. A material discharge channel and an air channel are provided in the cooling section. The air channel is arranged around the material discharge channel. The cooling water coil 3 is arranged in the air channel. The cooling water inlet at one end of the cooling water coil 3 is filled with cooling water. The other end of the cooling water coil 3 is a low-temperature steam outlet.

[0085] In some embodiments, the feeding device is a silo 1, a feed pipe is connected between the silo 1 and the coke oven 2, and a feed valve is provided on the feed pipe.

[0086] In some embodiments, the unloading device includes a conveying device 5 and an active coke storage bin. The lower end of the coke making oven 2 is connected with a discharge pipe 4, and a discharge valve is provided on the discharge pipe 4. The discharge port of the discharge pipe 4 is located above the starting end of the conveying device 5, and the active coke storage bin is located below the tail end of the conveying device 5.

[0087] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0088] Example 1

[0089] A method for improving the quality of tail gas in the process of preparing activated coke,

[0090] The device for improving the quality of tail gas in the process of preparing activated coke includes:

[0091] Steam generator 6, first CO 2 Absorption section 7, reforming section 8, heat exchanger 9 and second CO 2 Absorption section 10,

[0092] The steam generator 6 has a first heat release channel and a first heat absorption channel, the first heat release channel is provided with a first heat release side inlet and a first heat release side outlet, the first heat release side inlet is used to connect to the tail gas outlet of the coke oven 2, the first heat absorption channel is provided with a first heat absorption side inlet and a first heat absorption side outlet, the first heat absorption side outlet is used to connect to the high-temperature steam inlet of the coke oven 2;

[0093] The first CO 2 The absorption section 7 is provided with a first tail gas inlet and a first tail gas outlet, wherein the first tail gas inlet is connected to the first heat release side outlet; 2 The absorption section 7 is provided with carbide slag;

[0094] The reforming section 8 is provided with a first steam inlet, a second tail gas inlet and a second tail gas outlet, the first steam inlet is communicated with the first heat absorption side outlet, and the second tail gas inlet is communicated with the first tail gas outlet; the reforming section 8 is provided with red mud; the reforming section 8 is provided with a microwave heating device for performing microwave heating on the reforming section 8;

[0095] The heat exchanger 9 has a second heat release channel and a second heat absorption channel, the second heat release channel is provided with a second heat release side inlet and a second heat release side outlet, the second heat release side inlet is connected to the second tail gas outlet, the second heat absorption channel is provided with a second heat absorption side inlet and a second heat absorption side outlet, the second heat absorption side inlet is used to connect to the low-temperature water vapor outlet of the coke oven 2, and the second heat absorption side outlet is connected to the first heat absorption side inlet;

[0096] The second CO 2 The absorption section 10 is provided with a third tail gas inlet and a third tail gas outlet, wherein the third tail gas inlet is connected to the second heat release side outlet; 2 The absorption section 10 is provided with carbide slag.

[0097] The quality improvement method includes the following steps:

[0098] (1) Coke oven 2 generates tail gas during the coking process. The tail gas temperature is 750°C. In terms of volume fraction, the tail gas includes 30% H 2 , 12% CO 2 , 20% CO, 22% CH 4 and 10% tar.

[0099] (2) The tail gas is introduced into the steam generator 6 for cooling.

[0100] (3) The tail gas cooled by the steam generator 6 is introduced into the first CO 2 Absorption stage 7, absorption of CO 2 , the first CO 2 The temperature in absorption section 7 was 450°C.

[0101] (4) Then absorb CO 2 The tail gas after the steam is fed into the reforming section 8 for steam catalytic reforming. The steam generated by the steam generator 6 is introduced into the reforming section 8 and mixed with the tail gas. In the mixed gas, the H 2The O / C ratio is 3:1; the reforming section 8 is heated by microwaves and natural gas, the temperature of the reforming section 8 is 800°C, and the temperature of the introduced water vapor is 450°C.

[0102] (5) After being reformed in the reforming section 8, the tail gas enters the heat exchanger 9 for cooling.

[0103] (6) After lowering the temperature, enter the second CO 2 Absorption section 10 absorbs CO 2 , the second CO 2 The temperature of the absorption section 10 is 200°C, and hydrogen-rich combustible gas is obtained. The tar removal rate is 98%, the hydrogen content increases by 35%, and the CO 2 The content is 0.3%.

[0104] Example 2

[0105] A method for improving the quality of tail gas in the process of preparing activated coke,

[0106] The device used for upgrading the tail gas during the preparation of activated coke is exactly the same as that in Example 1.

[0107] The quality improvement method includes the following steps:

[0108] (1) Coke oven 2 generates tail gas during the coking process. The tail gas temperature is 700°C. In terms of volume fraction, the tail gas includes 25% H 2 , 13% CO 2 , 25% CO, 20% CH 4 and 13% tar.

[0109] (2) The tail gas is introduced into the steam generator 6 for cooling.

[0110] (3) The tail gas cooled by the steam generator 6 is introduced into the first CO 2 Absorption stage 7, absorption of CO 2 , the first CO 2 The temperature in absorption section 7 was 350°C.

[0111] (4) Then absorb CO 2 The tail gas after the steam is fed into the reforming section 8 for steam catalytic reforming. The steam generated by the steam generator 6 is introduced into the reforming section 8 and mixed with the tail gas. In the mixed gas, the H 2 The O / C ratio is 5:1; the reforming section 8 is heated by microwaves and natural gas, the temperature of the reforming section 8 is 850°C, and the temperature of the introduced water vapor is 400°C.

[0112] (5) After being reformed in the reforming section 8, the tail gas enters the heat exchanger 9 for cooling.

[0113] (6) After lowering the temperature, enter the second CO 2 Absorption section 10 absorbs CO 2 , the second CO 2 The temperature of the absorption section 10 is 230°C, and hydrogen-rich combustible gas is obtained. The tar removal rate is 99%, the hydrogen content increases by 43%, and the CO 2 The content is 0.7%.

[0114] Example 3

[0115] A method for improving the quality of tail gas in the process of preparing activated coke,

[0116] The device used for upgrading the tail gas during the preparation of activated coke is exactly the same as that in Example 1.

[0117] The quality improvement method includes the following steps:

[0118] (1) Coke oven 2 generates tail gas during the coking process. The tail gas temperature is 800°C. In terms of volume fraction, the tail gas includes 45% H 2 , 8% CO 2 , 15% CO, 22% CH 4 and 6% tar.

[0119] (2) The tail gas is introduced into the steam generator 6 for cooling.

[0120] (3) The tail gas cooled by the steam generator 6 is introduced into the first CO 2 Absorption stage 7, absorption of CO 2 , the first CO 2 The temperature in absorption section 7 was 450°C.

[0121] (4) Then absorb CO 2 The tail gas after the steam is fed into the reforming section 8 for steam catalytic reforming. The steam generated by the steam generator 6 is introduced into the reforming section 8 and mixed with the tail gas. In the mixed gas, the H 2 The O / C ratio is 3:1; the reforming section 8 is heated by microwaves and coal powder, the temperature of the reforming section 8 is 800°C, and the temperature of the introduced water vapor is 500°C.

[0122] (5) After being reformed in the reforming section 8, the tail gas enters the heat exchanger 9 for cooling.

[0123] (6) After lowering the temperature, enter the second CO 2 Absorption section 10 absorbs CO 2 , the second CO 2 The temperature of the absorption section 10 is 280°C, and hydrogen-rich combustible gas is obtained. The tar removal rate is 99%, the hydrogen content increases by 30%, and the CO2 The content is 1.2%.

[0124] Comparative Example 1

[0125] The method for upgrading the tail gas during the preparation of activated coke and the device and method for upgrading the tail gas during the preparation of activated coke are exactly the same as those in Example 1, except that the catalyst in the reforming furnace 8 is olivine.

[0126] The tar removal rate of the obtained hydrogen-rich combustible gas was 85%, the hydrogen content increased by 25%, and the CO 2 The content is 0.6%.

[0127] Comparative Example 2

[0128] The method for upgrading the tail gas during the preparation of activated coke and the device and method for upgrading the tail gas during the preparation of activated coke are exactly the same as those in Example 1, except that the catalyst in the reforming furnace 8 is calcined dolomite.

[0129] The tar removal rate of the hydrogen-rich combustible gas was 55%, the hydrogen content increased by 5%, and the CO 2 The content is 1.0%.

[0130] Comparative Example 3

[0131] The method for upgrading the tail gas during the preparation of activated coke and the device and method for upgrading the tail gas during the preparation of activated coke are exactly the same as those in Example 1, except that the tail gas of the coke oven 2 is directly introduced into the first CO 2 In the absorption section 7, the temperature is not reduced by the steam generator 6, and the steam generator 6 is heated by the natural gas boiler to generate high-temperature water vapor.

[0132] The tar removal rate of the obtained hydrogen-rich combustible gas was 92%, the hydrogen content increased by 18%, and the CO 2 The content is 1.8%.

[0133] Comparative Example 4

[0134] The method for upgrading the tail gas during the preparation of activated coke and the device and method for upgrading the tail gas during the preparation of activated coke are exactly the same as those in Example 1, except that step (3) is omitted, that is, the tail gas after cooling by the steam generator 6 is directly introduced into the reforming section 8.

[0135] The tar removal rate of the obtained hydrogen-rich combustible gas was 90%, the hydrogen content increased by 13%, and the CO 2 The content is 1.8%.

[0136] Comparative Example 5

[0137] The method for upgrading the tail gas during the preparation of activated coke and the device and method for upgrading the tail gas during the preparation of activated coke are exactly the same as those in Example 1, except that step (6) is omitted, that is, the tail gas does not enter the second CO after being cooled by the heat exchanger 9. 2 The absorption section 10 directly obtains the final hydrogen-rich combustible gas.

[0138] The tar removal rate of the obtained hydrogen-rich combustible gas was 98%, the hydrogen content increased by 28%, and the CO 2 The content is 10%.

[0139] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0140] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0141] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0142] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A device for improving the quality of tail gas in the process of preparing activated coke, characterized in that: include: A steam generator, wherein the steam generator has a first heat release channel and a first heat absorption channel, wherein the first heat release channel is provided with a first heat release side inlet and a first heat release side outlet, wherein the first heat release side inlet is used to communicate with an exhaust gas outlet of a coke oven, and the first heat absorption channel is provided with a first heat absorption side inlet and a first heat absorption side outlet, wherein the first heat absorption side outlet is used to communicate with a high-temperature steam inlet of the coke oven; A first CO2 absorption section, wherein the first CO2 absorption section is provided with a first tail gas inlet and a first tail gas outlet, and the first tail gas inlet is connected to the first heat release side outlet; A reforming section, wherein the reforming section is provided with a first steam inlet, a second tail gas inlet, and a second tail gas outlet, wherein the first steam inlet is communicated with the first heat absorption side outlet, and the second tail gas inlet is communicated with the first tail gas outlet; A heat exchanger, wherein the heat exchanger has a second heat release channel and a second heat absorption channel, the second heat release channel is provided with a second heat release side inlet and a second heat release side outlet, the second heat release side inlet is communicated with the second tail gas outlet, the second heat absorption channel is provided with a second heat absorption side inlet and a second heat absorption side outlet, the second heat absorption side inlet is used to communicate with the low-temperature water vapor outlet of the coke oven, and the second heat absorption side outlet is communicated with the first heat absorption side inlet; The second CO2 absorption section is provided with a third tail gas inlet and a third tail gas outlet, and the third tail gas inlet is communicated with the second heat release side outlet.

2. The device for improving the quality of tail gas in the process of preparing activated coke according to claim 1, characterized in that: The reforming section is provided with a microwave heating device for performing microwave heating on the reforming section.

3. The device for improving the quality of tail gas in the process of preparing activated coke according to claim 1, characterized in that: The first CO2 absorption section is provided with carbide slag; And / or, the reforming section is provided with red mud; And / or, the second CO2 absorption section is provided with carbide slag.

4. A method for improving the quality of tail gas in the process of preparing activated coke, characterized in that: The device for improving the quality of tail gas in the activated coke preparation process according to any one of claims 1 to 3 comprises the following steps: (1) The coke oven generates tail gas during the process of preparing activated coke, and the tail gas enters the steam generator for cooling; (2) The tail gas after being cooled by the steam generator enters the first CO2 absorption section to absorb CO2 in the tail gas; (3) The tail gas after absorbing CO2 enters the reforming section, mixes with the water vapor introduced into the reforming section, and undergoes steam catalytic reforming; (4) The tail gas after reforming in the reforming section enters the heat exchanger for cooling; (5) The cooled tail gas enters the second CO2 absorption section to absorb CO2 in the tail gas to obtain hydrogen-rich combustible gas.

5. The method for improving the quality of tail gas in the process of preparing activated coke according to claim 4, characterized in that: The first CO2 absorption stage uses carbide slag as CO2 absorbent; And / or, the reforming stage uses red mud as a catalyst and / or a microwave absorber; And / or, the second CO2 absorption stage uses carbide slag as the CO2 absorbent.

6. The method for improving the quality of tail gas in the process of preparing activated coke according to claim 4, characterized in that: In the step (1), the temperature of the tail gas generated by the coke oven is 550°C to 950°C.

7. The method for improving the quality of tail gas in the process of preparing activated coke according to claim 4, characterized in that: In the step (2), the temperature of the first CO2 absorption section is 200°C to 500°C.

8. The method for improving the quality of tail gas in the process of preparing activated coke according to claim 4, characterized in that: In the step (3), the reforming section is assisted by microwave heating; and / or, the reforming section is heated by an external heat source; and / or, the temperature of the reforming section is 700° C. to 900° C.; And / or, the temperature of the water vapor introduced into the reforming section is 450°C to 600°C.

9. The method for improving the quality of tail gas in the process of preparing activated coke according to claim 4, characterized in that: In the step (5), the temperature of the second CO2 absorption section is 100°C to 300°C.

10. An activated coke preparation system, characterized in that: The device for upgrading the exhaust gas during the preparation of activated coke comprises the device described in any one of claims 1 to 3, and also comprises a coke oven and a feeding device, wherein the coke oven is provided with a feeding port and a high-temperature water vapor inlet, the high-temperature water vapor inlet is communicated with the first heat absorption side outlet, the feeding port of the coke oven is connected to the feeding pipe of the feeding device, the coke oven is also provided with a cooling water coil, the cooling water coil is provided with a cooling water inlet and a low-temperature water vapor outlet, the low-temperature water vapor outlet is communicated with the second heat absorption side inlet.

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