Coal pyrolysis method and device for realizing in-situ tar ring addition modification

Abstract

The application discloses a coal pyrolysis method and device for realizing in-situ ring-enriching modification of tar, and the method is as follows: block coal is pyrolyzed to obtain coal tar, semi-coke and pyrolysis gas; the coal tar and a ring-enriching modifier are subjected to in-situ ring-enriching modification reaction in a coal pyrolysis device under hydrogen to obtain coal tar; the in-situ ring-enriching modification reaction temperature is 200-250 DEG C, and the reaction pressure is 101-120 KPa.The coal tar obtained by the method is rich in polycyclic aromatic hydrocarbons and is suitable for being used as a processing raw material of high-density fuel.The device introduces the ring-enriching modification reaction on the basis of the coal pyrolysis, so that the coal tar is subjected to in-situ ring-enriching modification in the pyrolysis, and the obtained coal tar is more suitable for being used as the processing raw material of the high-density fuel.The pyrolysis device has the characteristics of low cost and low heat loss.

Description

A method and apparatus for in-situ cyclopyrolysis of coal to achieve tar cyclic modification Technical Field

[0001] This invention belongs to the field of coal pyrolysis technology and relates to a method and apparatus for realizing in-situ cyclization modification of coal tar. Background Technology

[0002] Coal tar is a liquid product obtained from the dry distillation and gasification of coal. Based on the pyrolysis temperature, coal tar can be classified into low-temperature coal tar (dry distillation temperature 450–650℃), medium-low-temperature coal tar (partially low-temperature or medium-temperature producer coal tar, dry distillation temperature 600–800℃), medium-temperature coal tar (dry distillation temperature 700–900℃), and high-temperature coal tar (dry distillation temperature around 1000℃). In the coal pyrolysis reaction, its yield can reach 20%–40%. Medium-low-temperature pyrolysis coal tar contains compounds with a relatively high mass fraction of naphthalene and onion, which are polycyclic aromatic hydrocarbons (PAHs) and have limited applications in other fields. Both medium-low-temperature and high-temperature coal tar contain PAHs, which are very suitable as raw materials for producing high-density fuels. However, because the number of rings and other properties of PAHs in coal tar differs from other production raw materials, coal tar obtained from pyrolysis reactions in most technologies requires further processing to improve the properties of the resulting high-density fuels.

[0003] In coal pyrolysis, the composition and quality of coal tar and semi-coke are difficult to control due to variations in pyrolysis temperature and coal feedstock composition. Therefore, many pyrolysis processes have emerged to improve coal tar quality. Currently, pyrolysis technologies mainly focus on moving bed, rotary kiln, fluidized bed, and entrained flow processes. Moving bed pyrolysis technology offers relatively stable material movement and volatile matter release within the furnace; rotary kiln pyrolysis technology allows for mixing of raw coal and some pyrolytic semi-coke within the furnace, resulting in rapid heat transfer and high energy utilization; fluidized bed and entrained flow pyrolysis processes feature smaller particle sizes, high heat transfer efficiency, and rapid heating. These are undoubtedly excellent coal pyrolysis technologies, but none of them are ideal for producing coal tar suitable for processing into high-density fuels.

[0004] Since coal tar only requires ring-enhancing modification to be more suitable for producing high-density fuels, achieving ring-enhancing modification in pyrolysis is significant, but current pyrolysis technologies have not yet realized this. High-energy-density fuels contain more energy per unit volume or weight. They typically have higher calorific values ​​and higher energy release rates, thus storing more energy in a relatively small space. The importance of high-energy-density fuels lies in their ability to provide more energy to meet the energy demands of modern society. These fuels can play a crucial role in space exploration, military applications, and civilian transportation. Currently, the polycyclic aromatic hydrocarbon components in coal tar produced by pyrolysis technology are generally cracked into more readily usable chemical feedstocks such as benzene, rather than used to produce high-density fuels, representing a significant technological gap. my country currently lacks dedicated reactors for producing high-density fuels from coal; spherical particle bed reactors or spray drying technologies are generally used, which are only suitable for processing petroleum feedstocks, failing to fully realize the value of coal and its byproducts. Summary of the Invention

[0005] To overcome the problem that existing technologies cannot produce high-density fuels, the present invention proposes a coal pyrolysis method and apparatus for in-situ ring-enhancing modification of coal tar. By performing in-situ ring-enhancing modification on nascent coal tar during pyrolysis, a novel pyrolysis process is formed that can produce coal tar rich in polycyclic aromatic hydrocarbons, laying the foundation for the subsequent processing of coal tar into high-density fuels.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A coal pyrolysis device for in-situ ring-enhancing modification of tar includes a cylinder, a lump coal inlet at the top of the cylinder, a crude product outlet at the upper part of the cylinder sidewall, a number of preheating receiving towers inside the cylinder, and a pyrolysis gas inlet and a ring-enhancing modifier inlet at the bottom of the cylinder sidewall; a number of gas distributors are provided on the preheating receiving towers.

[0008] Furthermore, from top to bottom, the distance between adjacent preheating trays gradually increases, and the increase is 20-40 mm; the gas distributor is a baffle.

[0009] Furthermore, the interior of the cylinder is divided into three parts from top to bottom. The topmost part is the first preheating tray, and the first part is the preheating space between the first preheating tray and the lump coal inlet. The height of the preheating space is 1000-2000 mm. The second part is the ring-enhancing and modification reaction space between the first preheating tray and the penultimate preheating tray. The height of the preheating space is 100-600 mm. The third part is the bottom semi-coke cooling space, which is equipped with a heat exchanger.

[0010] Furthermore, the temperature of the preheating space is 500℃~600℃, and a heat exchanger is installed above the first preheating tray.

[0011] Furthermore, the spacing between adjacent preheating trays in the reaction space gradually increases from top to bottom, with the increasing distance being 20–40 mm.

[0012] Furthermore, the angle between the gas distributor and the preheating tray is 60° to 80°; each preheating tray is provided with several sieve holes, the opening rate of each preheating tray is 30% to 40%, and the diameter of the sieve holes is 10 to 20 mm.

[0013] Furthermore, a coke quenching pool is provided below the cylinder, and a coke quenching pool outlet is provided on the side wall of the coke quenching pool; the bottom preheating receiving tower plate serves as a semi-coke cooling tower plate.

[0014] Furthermore, a preheating heat exchanger is installed on the preheating receiving tower plate.

[0015] A method for in-situ cyclopyrolysis of coal based on the aforementioned device to achieve tar ring-modification includes the following steps:

[0016] Pyrolysis of lump coal yields coal tar, semi-coke, and pyrolysis gas.

[0017] Coal tar is subjected to an in-situ ring-promoting reaction with a ring-promoting modifier in a coal pyrolysis unit under hydrogen atmosphere to obtain coal tar; the in-situ ring-promoting reaction temperature is 200-250℃ and the reaction pressure is 101-120 kPa.

[0018] Furthermore, the ring-enhancing modifier is a gaseous mixture of 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene in a molar ratio of 2 to 4:1.

[0019] Furthermore, the solid flow rate of the lump coal is 100–120 g / s, and the flow rate of the ring-enhancing modifier is 1–2 m / s.

[0020] Furthermore, the particle size of the lump coal is 5-10 mm, and the surface of the lump coal is sprayed with a 5% ferric chloride solution, with the mass ratio of the ferric chloride solution to the lump coal being 1:100-120.

[0021] Ferric chloride and cyclopentadiene are added to the gaseous product of the in-situ cyclization modification reaction to form a gaseous mixture, which is then passed into a pyrolysis apparatus.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention achieves in-situ ring-enhancing during coal pyrolysis by setting up a lump coal inlet, a pyrolysis gas inlet, and a ring-enhancing agent inlet. This device introduces a ring-enhancing modification reaction based on coal pyrolysis, enabling in-situ ring-enhancing modification of coal tar during pyrolysis, making the resulting coal tar more suitable as a processing feedstock for high-density fuels. This pyrolysis device features low cost and low heat loss.

[0024] Furthermore, this device uses a large number of baffles as gas distributors. Using this device in a gas-solid reactor can make the reactants come into more complete contact, allowing them to reach the required reaction time, and the overall airflow distribution is more uniform, resulting in higher raw material utilization.

[0025] Furthermore, the pyrolysis unit is equipped with a longer reaction section, which allows the raw material lump coal to be fully pyrolyzed. The pyrolyzed coal tar is blown upward by the rising ring-enhancing modifier airflow at the bottom as it falls. Moreover, it passes through the preheating receiving tower plate with large sieve holes and many openings and the airflow distributor on the preheating receiving tower plate, which increases the residence time and makes the reaction more thorough, thus forming a better ring-enhancing modification effect.

[0026] In this invention, coal tar is obtained by pyrolysis of lump coal. The coal tar is then subjected to an in-situ ring-enlarging modification reaction with a ring-enlarging modifier in a coal pyrolysis device under hydrogen atmosphere to obtain coal tar rich in polycyclic aromatic hydrocarbons, which is suitable as a processing feedstock for high-density fuels.

[0027] Furthermore, this invention uses common lump coal as raw material, and the raw material does not need to be crushed and flotated, and can be reacted directly in the reactor. The ring-enlarging modifiers selected are 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene, which have high reactivity. Under higher temperature and in a weakly acidic environment provided by phenolic substances contained in coal tar components, the fused ring substances in coal tar and the ring-enlarging modifier can better carry out the ring-enlarging modification reaction. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the pyrolysis apparatus of the present invention.

[0029] Figure 2 is a cross-sectional view along A-A' in Figure 1;

[0030] Explanation of reference numerals in the attached figures:

[0031] 110. Raw material inlet; 120. Crude product outlet; 130. Pyrolysis gas inlet; 140. Ring-enhancing modifier inlet; 150. Semi-coke outlet; 160. Coke burner outlet; 210. Preheating tray; 220. Sieve; 310. Gas distributor. Detailed Implementation

[0032] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0033] The present invention provides a coal pyrolysis method for achieving in-situ pyrolysis modification of tar, comprising the following steps:

[0034] First, combustible gas is burned to provide heat to the heat exchanger. Using lump coal as the main raw material, coal tar, semi-coke and pyrolysis gas are obtained through pyrolysis reaction.

[0035] Secondly, the coal tar generated from the pyrolysis reaction undergoes in-situ ring-enlarging modification in a coal pyrolysis unit under a hydrogen atmosphere (hydrogen generated from the pyrolysis reaction and supplemented hydrogen) and with the combined action of a ring-enlarging modifier. The reaction temperature is 200–250℃ and the reaction pressure is 101–120 kPa. The ring-enlarging modifier reacts with the coal tar from bottom to top to obtain coal tar, while simultaneously increasing the content of polycyclic aromatic hydrocarbon components. The gaseous product after the reaction is sent out through the product outlet. After separation, the coal gas containing unreacted ring-enlarging modifier is recycled. Part of the heat of the semi-coke is recovered between the last tray and the semi-coke outlet, and then enters the coke resting tank as the semi-coke product.

[0036] The ring-enhancing modifier is a gaseous mixture of 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene after pretreatment (i.e., heating to a gaseous state).

[0037] The solid flow rate of the raw material lump coal is 100-120 g / s, the molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene in the ring-enhancing modifier is 2-4:1, and the gas flow rate is 1-2 m / s.

[0038] Finally, after the modified coal tar is separated from the gaseous products obtained from the reaction, the coal gas containing the unreacted modifier is recycled to the gaseous feed inlet of the pyrolysis unit to participate in the reaction again.

[0039] The reaction of coal tar with a ring-promoting modifier under hydrogen atmosphere is as follows:

[0040]

[0041]

[0042] Where R is a methyl, carboxyl, or hydroxyl group.

[0043] Referring to Figure 1, a coal pyrolysis device for in-situ ring-enhancing modification of tar includes a cylinder. A lump coal inlet 110 is located at the top of the cylinder, and a crude product outlet 120 is located on the upper part of the cylinder side wall. Several preheating trays 210 are arranged inside the cylinder. Preferably, the crude product outlet 120 is located between the first and second preheating trays (counting from top to bottom), and between the second-to-last and third preheating trays. A pyrolysis gas inlet 130 and a ring-enhancing agent inlet 140 are located on the side wall between these two trays. A semi-coke outlet 150 is located at the bottom of the cylinder, and a quenching tank is located below the cylinder. A quenching tank outlet 160 is located on the side wall of the quenching tank. The last preheating tray serves as a semi-coke cooling tray.

[0044] Referring to Figures 1 and 2, no gas distributor is installed on the preheating tray between the lump coal inlet 110 and the coarse product outlet 120, or on the penultimate preheating tray. Several preheating heat exchangers 310 are installed on the upper and lower surfaces of the other preheating trays 210. After passing through each preheating tray 310 and the gas distributor 310, the lump coal is discharged from the semi-coke outlet 150. There are more than 6 preheating trays 310, and the distance between adjacent preheating trays 310 gradually increases from top to bottom, with the increase ranging from 20 to 40 mm.

[0045] The semi-coke obtained from pyrolysis leaves the pyrolysis unit through the bottom preheating tray and enters the coke drying tank to obtain the semi-coke product.

[0046] The pyrolysis unit is divided into three parts from top to bottom. The first preheating tray is the one closest to the lump coal inlet 110. The first part is the preheating space between the first preheating tray and the lump coal inlet 110. The height of the preheating space is 1000-2000 mm, and the temperature is 500℃-600℃. A heat exchanger is installed above the first preheating tray after preheating. The second part is the main reaction space for ring-enhancing modification between the first preheating tray and the penultimate tray. In the second part, the ring-enhancing modifier is fully mixed with the tar from the pyrolysis of raw lump coal to carry out the ring-enhancing modification reaction. The distance between each tray in the main reaction space increases from top to bottom by 20-40 mm. The distance between each tray between the first preheating tray and the second to last tray is 100-600 mm. The third part is the bottom semi-coke cooling space, which is equipped with a heat exchanger to recover some of the heat from the semi-coke. After the heat exchange, the temperature of the semi-coke is 100-150℃.

[0047] Preferably, each tray between the two gas inlets and outlets is provided with at least four inclined gas distributors, and the angle of each gas distributor (the angle between it and the tray) is 60° to 80°; each preheating tray of the device is provided with a number of sieve holes 220, the opening ratio of each preheating tray is preferably 30% to 40%, and the diameter of the sieve holes 220 is preferably 10 to 20 mm; no gas-solid separator is provided on the first and last preheating trays of the device, and the distance from the last tray to the bottom surface of the shell is 200 to 400 mm.

[0048] Before entering the first stage, the lump coal should undergo a certain crushing process, with a particle size of 5-10 mm, to maintain a reaction time of 2-3 hours. The crushed lump coal is then sprayed with a 5% ferric chloride solution, with a mass ratio of ferric chloride solution to lump coal of 1:100-120. Ferric chloride serves as a catalyst for the in-situ ring-enhancing modification reaction.

[0049] During the separation of the gaseous products generated from the pyrolysis reaction, ferric chloride and cyclopentadiene are added as separation media, along with a certain amount of hydrogen. The mass ratio of ferric chloride solution to cyclopentadiene is 1:10–20. The separated gas-liquid mixture is first subjected to heat exchange to become a gaseous mixture before being recycled back into the reaction apparatus. Ferric chloride serves as a catalyst supplement, and cyclopentadiene is another ring-enlarging modifier added. After preliminary separation of the gaseous products, the resulting gas containing unreacted ring-enlarging modifier is heated to 250–300°C via a heat exchanger before entering the pyrolysis unit through a circulation pipeline.

[0050] After preheating and heat exchange, the temperature of lump coal is 240-250℃; the temperature of semi-coke in the coke resting tank is 40-60℃, and the semi-coke is output as a product after cooling.

[0051] In this invention, the gas distributor is a baffle plate.

[0052] Examples 1-11 illustrate this by varying the flow rate of the ring-increasing modifier.

[0053] Example 1

[0054] The apparatus of this embodiment employs a preheating section with a length of 2000 mm, a gas distributor with an angle of 60° to the tray, a spacing of 400 mm between the first and penultimate preheating trays, a tray opening ratio of 35%, a sieve aperture diameter of 20 mm, a preheating section heat exchange temperature of 600 °C, a tray spacing of 40 mm, a solid flow rate of 100 g / s for the raw material lump coal with a particle size of 10 mm, a molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene in the raw material of 3:1, the use of 95% cyclopentadiene and 5% ferric chloride solution as the separation raw material, and a gas flow rate of 1 m / s for the ring-enhancing modifier.

[0055] The coal tar type obtained from the pyrolysis of lump coal selected in this embodiment is D307, and the composition (wt%) of this coal tar is shown in Table 1-1:

[0056] Table 1-1 Composition of Coal Tar

[0057]

[0058] The composition (V%) of the pyrolysis gas from the raw material lump coal in this embodiment is shown in Table 1-2:

[0059] Table 1-2 Components of Pyrolysis Gas

[0060] Project D3O7H25.40CO7.10CO217.77CH44.12N257.97O20.088C2 and C2+1.12H2S0.062H2O6.32SO30.05 surface

[0061] During operation, 1000 kg of lump coal is fed into the unit through the inlet, while ring modifiers and raw materials are fed in simultaneously. The rapid pyrolysis section needs to be preheated for a period of time beforehand.

[0062] Example 2

[0063] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.1 m / s.

[0064] Example 3

[0065] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.2 m / s.

[0066] Example 4

[0067] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.3 m / s.

[0068] Example 5

[0069] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.4 m / s.

[0070] Example 6

[0071] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.5 m / s.

[0072] Example 7

[0073] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.6 m / s.

[0074] Example 8

[0075] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.7 m / s.

[0076] Example 9

[0077] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.8 m / s.

[0078] Example 10

[0079] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 1.9 m / s.

[0080] Example 11

[0081] The difference from Example 1 is that the gas flow rate of the ring-enhancing modifier is 2.0 m / s. The test results of the coal tar ring-enhancing modification are shown in Tables 1-3:

[0082] Table 1-3 Test results of ring-addition modification of coal tar

[0083]

[0084]

[0085] As can be seen from Table 1-3, the content of polycyclic aromatic hydrocarbons (bicyclic and tricyclic) in coal tar is low, and the content increases with the increase of the ring-enhancing modifier and the gas flow rate.

[0086] Examples 12-22 illustrate this by varying the flow rate of the ring-increasing modifier.

[0087] Example 12

[0088] The apparatus of this embodiment employs a preheating section with a length of 2000 mm, a gas distributor with an angle of 60° to the tray, a spacing of 400 mm between the first and penultimate preheating trays, a tray opening ratio of 35%, a sieve aperture diameter of 20 mm, a preheating section heat exchange temperature of 600°C, a 40 mm increase in the spacing between each tray, a solid flow rate of 100 g / s for the raw material lump coal with a particle size of 10 mm, a molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene of 3:1 in the raw material, and uses 95% cyclopentadiene and 5% ferric chloride solution as the separation raw material by mass percentage; the gas flow rate of the ring-enhancing modifier is 1 m / s.

[0089] The coal tar obtained from the pyrolysis of lump coal selected in this embodiment is of type C-301. The composition (wt%) of this coal tar is shown in Table 2-1:

[0090] Table 2-1 Composition of Coal Tar

[0091]

[0092]

[0093] The composition (V%) of the pyrolysis gas from the raw material lump coal in this embodiment is shown in Table 2-2:

[0094] Table 2-2 Components of Pyrolysis Gas

[0095] The project consists of C-301H2 6.83%, CO 6.45%, CO2 14.85%, CH4 5.17%, N2 57.828%, O2 0.075%, C2 and C2+ 2.21%, H2S 0.087%, H2O 5.89%, SO3 0.07%. surface

[0096] During operation, 1000 kg of lump coal is fed into the unit through the inlet, while ring modifiers and raw materials are fed in simultaneously. The rapid pyrolysis section needs to be preheated for a period of time beforehand.

[0097] Example 13

[0098] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.1 m / s.

[0099] Example 14

[0100] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.2 m / s.

[0101] Example 15

[0102] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.3 m / s.

[0103] Example 16

[0104] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.4 m / s.

[0105] Example 17

[0106] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.5 m / s.

[0107] Example 18

[0108] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.6 m / s.

[0109] Example 19

[0110] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.7 m / s.

[0111] Example 10

[0112] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.8 m / s.

[0113] Example 21

[0114] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 1.9 m / s.

[0115] Example 22

[0116] The difference from Example 12 is that the gas flow rate of the ring-enhancing modifier is 2.0 m / s.

[0117] The test results of cyclization modification of coal tar are shown in Table 2-3:

[0118] Table 2-3 Test results of ring-modification of coal tar

[0119]

[0120] As can be seen from Table 2-3, the content of polycyclic aromatic hydrocarbons (bicyclic and tricyclic) in coal tar is low, and increases with the increase of the gas flow rate of the ring-enhancing modifier.

[0121] Examples 23-33 illustrate this by varying the flow rate of the ring-increasing modifier.

[0122] Example 23

[0123] The apparatus of this embodiment employs a preheating section with a length of 2000 mm, a gas distributor with an angle of 60° to the tray, a spacing of 400 mm between the first and penultimate preheating trays, a tray opening ratio of 35%, a sieve aperture diameter of 20 mm, a preheating section heat exchange temperature of 600°C, a 40 mm increase in the spacing between each tray, a solid flow rate of 100 g / s for the raw material lump coal with a particle size of 10 mm, a molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene in the raw material of 3:1, and the use of a 95% cyclopentadiene and 5% ferric chloride solution as the separation raw material; and a gas flow rate of 1 m / s for the ring-enhancing modifier.

[0124] The coal tar obtained from the pyrolysis of lump coal selected in this embodiment is of type P-301. The composition (wt%) of this coal tar is shown in Table 3-1:

[0125] Table 3-1 Composition of Coal Tar

[0126]

[0127] The composition (V%) of the pyrolysis gas from the raw material lump coal in this embodiment is shown in Table 3-2:

[0128] Table 3-2 Composition of pyrolysis gas

[0129] Project P-301H28.60CO6.54CO219.20CH46.28N249.775O20.01C2 and C2+1.54H2S0.085H2O7.67SO30.08 surface

[0130] During operation, 1000 kg of lump coal is fed into the unit through the inlet, while ring modifiers and raw materials are fed in simultaneously. The rapid pyrolysis section needs to be preheated for a period of time beforehand.

[0131] Example 24

[0132] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.1 m / s.

[0133] Example 25

[0134] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.2 m / s.

[0135] Example 26

[0136] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.3 m / s.

[0137] Example 27

[0138] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.4 m / s.

[0139] Example 28

[0140] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.5 m / s.

[0141] Example 29

[0142] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.6 m / s.

[0143] Example 30

[0144] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.7 m / s.

[0145] Example 31

[0146] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.8 m / s.

[0147] Example 32

[0148] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier is 1.9 m / s.

[0149] Example 33

[0150] The difference from Example 23 is that the gas flow rate of the ring-enhancing modifier was 2.0 m / s. The test results for the ring-enhancing modification of coal tar are shown in Table 3-3:

[0151] Table 3-3 Test Results of Coal Tar Ring-Enhancing Modification

[0152]

[0153]

[0154] As can be seen from Table 3-3, the content of polycyclic aromatic hydrocarbons (bicyclic and tricyclic) in coal tar is low, and increases with the increase of the gas flow rate of the ring-enhancing modifier.

[0155] Example 34

[0156] The apparatus of this embodiment employs a preheating section with a length of 1000 mm, an angle of 80° between the gas distributor and the tray, a spacing of 100 mm between the first and penultimate preheating trays, a tray opening ratio of 40%, a sieve aperture diameter of 10 mm, a preheating section heat exchange temperature of 550°C, a 40 mm increase in the spacing between each tray, a solid flow rate of 110 g / s for the raw material lump coal with a particle size of 20 mm, a molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene in the raw material of 4:1, a mass ratio of ferric chloride solution to cyclopentadiene of 1:10, and a gas flow rate of 1 m / s for the ring-enhancing modifier.

[0157] Example 35

[0158] The apparatus of this embodiment employs a preheating section with a length of 1500 mm, a gas distributor with an angle of 70° to the tray, a spacing of 600 mm between the first and penultimate preheating trays, a tray opening ratio of 30%, a sieve aperture diameter of 15 mm, a preheating section heat exchange temperature of 500°C, a tray spacing of 40 mm, a solid flow rate of 120 g / s for the raw material lump coal with a particle size of 15 mm, a molar ratio of 2,3-dimethyl-1,3-butadiene to 1,3-cyclohexadiene in the raw material of 2:1, a mass ratio of ferric chloride solution to cyclopentadiene of 1:20, and a gas flow rate of 1 m / s for the ring-enhancing modifier.

[0159] As can be seen from the above examples, the content of polycyclic aromatic hydrocarbons (bicyclic and tricyclic) in coal tar generally increases with the increase of the gas flow rate of the ring-enhancing modifier. However, considering the economic cost of increasing the gas flow rate, a gas flow rate of 1.5 m / s for the ring-enhancing modifier is recommended here.

[0160] The above description is only of the preferred embodiment of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All variations made within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0161] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A coal pyrolysis device for achieving in-situ cyclohexane modification of tar, characterized in that, The system includes a cylinder body, with a lump coal inlet (110) at the top and a coarse product outlet (120) on the upper part of the cylinder side wall. Several preheating trays (210) are installed inside the cylinder body, and a pyrolysis gas inlet (130) and a ring-enhancing modifier inlet (140) are installed at the bottom of the cylinder side wall. Several gas distributors (310) are installed on the preheating trays (210). The angle between the gas distributors (310) and the preheating trays (210) is 60°–80°. Each preheating tray (210) has several sieve holes (220), and the opening rate of each preheating tray (210) is 30%–40%. The interior of the cylinder body... The tower is divided into three parts from top to bottom. The topmost preheating tray is the first preheating tray. The first part is the preheating space between the first preheating tray and the lump coal inlet (110). The height of the preheating space is 1000-2000 mm. The second part is the ring-enhancing and modification reaction space between the first preheating tray and the second-to-last preheating tray. The height of the ring-enhancing and modification reaction space is 100-600 mm. The third part is the bottom semi-coke cooling space, which is equipped with a heat exchanger. The distance between two adjacent preheating trays in the ring-enhancing and modification reaction space gradually increases from top to bottom, with the increasing distance being 20-40 mm.

2. The coal pyrolysis apparatus for achieving in-situ tar ring-enhancing modification according to claim 1, characterized in that, From top to bottom, the distance between adjacent preheating trays (210) gradually increases, and the increase is 20-40 mm; the gas distributor (310) is a baffle.

3. The coal pyrolysis apparatus for achieving in-situ pyrolysis modification of tar according to claim 1, characterized in that, The temperature of the preheating space is 500℃~600℃, and a heat exchanger is installed above the first preheating tray.

4. The coal pyrolysis apparatus for achieving in-situ pyrolysis modification of tar according to claim 1, characterized in that, The diameter of the sieve aperture (220) is 10-20 mm.

5. A method for in-situ cyclohexane modification of coal tar based on the apparatus described in any one of claims 1-4, characterized in that, Includes the following steps: Coal tar, semi-coke, and pyrolysis gas are obtained by pyrolysis of lump coal. Coal tar and a ring-enlarging modifier are then subjected to an in-situ ring-enlarging modification reaction in a coal pyrolysis unit under hydrogen atmosphere to obtain coal tar. The in-situ ring-enlarging modification reaction temperature is 200–250℃, and the reaction pressure is 101–120 kPa. The ring-enlarging modifier is a gaseous mixture of 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene in a molar ratio of 2–4:

1.

6. The coal pyrolysis method for achieving in-situ pyrolysis modification of tar according to claim 5, characterized in that, The solid flow rate of lump coal is 100-120 g / s, and the flow rate of the ring modifier is 1-2 m / s.

7. The coal pyrolysis method for achieving in-situ cyclohexane modification of tar according to claim 5, characterized in that, The lump coal has a particle size of 5-10 mm, and the surface of the lump coal is sprayed with a 5% ferric chloride solution. The mass ratio of ferric chloride solution to lump coal is 1:100-120. Ferric chloride and cyclopentadiene are added to the gaseous product of the in-situ cyclization modification reaction to form a gaseous mixture, which is then passed into the pyrolysis device.

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