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CN-116059931-B - Raw gas heat recovery and coal tar pretreatment device and application

CN116059931BCN 116059931 BCN116059931 BCN 116059931BCN-116059931-B

Abstract

The invention discloses a raw gas heat recovery and coal tar pretreatment device which comprises a fluidized bed hydrogenation reactor and an inner component, wherein the inner component comprises a heat exchanger arranged in the middle part and a gas-liquid-solid three-phase separator arranged in the upper part, a microspherical catalyst or microspherical inert filler is filled in the position of the heat exchanger in the fluidized bed hydrogenation reactor, and the microspherical catalyst or the microspherical inert filler is in a boiling state and washes the outer surface of a tube bundle of the heat exchanger in a use state. The device can effectively pretreat the coal tar while recovering the heat of the high-temperature raw gas, thereby laying a foundation for subsequent processing.

Inventors

  • HU SHAOJIAN
  • ZHANG ZHONGQING
  • YAO CHUNLEI
  • QUAN HUI
  • ZHAO WEI

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司大连石油化工研究院

Dates

Publication Date
20260505
Application Date
20211030

Claims (20)

  1. 1. The utility model provides a raw coke oven gas heat recovery, coal tar pretreatment method, wherein, raw coke oven gas heat recovery, coal tar pretreatment device includes: (1) The boiling bed hydrogenation reactor comprises a vertical cylinder and an internal component; (2) The internal components of the fluidized bed hydrogenation reactor comprise a heat exchanger arranged in the middle part and a gas-liquid-solid three-phase separator arranged in the upper part; (3) The bottom of the fluidized bed hydrogenation reactor is provided with a feed inlet, the top of the fluidized bed hydrogenation reactor is provided with a gas phase material discharge outlet, and the side wall of the gas-liquid-solid three-phase separator is provided with a liquid phase discharge outlet; (4) The position of a heat exchanger in the ebullated bed hydrogenation reactor is filled with a microsphere catalyst or a microsphere inert filler; (5) In the gas-liquid-solid three-phase separator area, the separated gas phase is discharged from the top of the reactor, the liquid phase is discharged from the liquid phase discharge port, and the microspherical catalyst or microspherical inert filler is circulated back to the middle part and the lower part of the reactor; the heat exchanger is a tube type heat exchanger, and the gaps among the tubes are more than 3 times of the diameter of the microsphere type catalyst or the microsphere type inert filler; The diameter of the microspherical catalyst or the microspherical inert filler is 0.2-1.2 mm, and the filling amount of the microspherical catalyst or the microspherical inert filler is 5-60% of the volume of the reactor in a static state; raw gas with the temperature of 450-850 ℃ led out by a coking device or a coal carbonization device directly enters a fluidized bed hydrogenation reactor, and coal tar pretreatment is carried out while heat recovery is carried out; The method comprises the steps of carrying out a fluidized bed hydrogenation reaction, wherein the average reaction temperature in the fluidized bed hydrogenation reaction is 180-420 ℃, controlling the reaction temperature in a heat exchange mode and recovering the heat of raw coke oven gas, and recovering light coal tar and coal gas after the gas phase discharged from the top of the fluidized bed hydrogenation reaction is subjected to heat exchange and/or ammonia water spray cooling; The reaction pressure of the ebullated bed hydrogenation reactor is normal pressure or is operated under the pressure of not higher than 6 MPa gauge by a pressurizing mode; And filling at least half of the volume of heavy oil before the boiling bed hydrogenation reactor is introduced into the raw gas, and simultaneously adding a microspherical catalyst or microspherical inert filler, wherein the heavy oil is kept in a liquid phase state under the reaction condition, and the heavy oil is from heavy coal tar or other heavy hydrocarbons of the device.
  2. 2. The method according to claim 1, wherein the average reaction temperature in the ebullated-bed hydrogenation reactor is 220-380 ℃.
  3. 3. The method according to claim 1, wherein the average reaction temperature in the ebullated-bed hydrogenation reactor is 260 to 350 ℃.
  4. 4. The method of claim 1, wherein the coking unit or the coal carbonization unit is a unit for producing coke, semicoke, byproduct coal tar and coal gas by heat treatment using coal as raw material.
  5. 5. The method of claim 1, wherein the raw gas temperature is 600-800 ℃.
  6. 6. The process of claim 1 wherein the heavy oil suspension bed hydrogenation catalyst is added to the ebullated bed hydrogenation reactor, comprising a water soluble suspension bed hydrogenation catalyst or an oil soluble suspension bed hydrogenation catalyst, the suspension bed hydrogenation catalyst comprising a material of at least one element from group VIB and group VIII of the periodic Table of elements.
  7. 7. The method of claim 6, wherein the heavy oil suspension bed hydrogenation catalyst is added to the ebullated bed hydrogenation reactor as a powdered suspension bed hydrogenation catalyst.
  8. 8. The method of claim 6, wherein the suspension bed hydrogenation catalyst is a material comprising at least one element selected from the group consisting of cobalt, molybdenum, nickel, tungsten, and iron.
  9. 9. The method of claim 6, wherein the addition amount of the suspended bed hydrogenation catalyst additive is 50-50000 mug/g based on the weight of elements.
  10. 10. The method of claim 9, wherein the addition amount of the suspended bed hydrogenation catalyst additive is 100-10000 mug/g based on the weight of elements.
  11. 11. The method of claim 9, wherein the addition amount of the suspended bed hydrogenation catalyst additive is 500-5000 mug/g based on the weight of elements.
  12. 12. The method of claim 7, wherein the powdered suspended bed hydrogenation catalyst is a 50 mesh pass through.
  13. 13. The method of claim 12, wherein the powdered suspended bed hydrogenation catalyst is a 100 mesh pass through.
  14. 14. The method of claim 12, wherein the powdered suspended bed hydrogenation catalyst is a 200 mesh pass through.
  15. 15. The method of claim 7, wherein the suspension bed hydrogenation catalyst comprises one or more of oxides, sulfides, sulfates, and organic compounds of cobalt, molybdenum, nickel, tungsten, and iron.
  16. 16. The method of claim 7, wherein the powdered suspended bed hydrogenation catalyst is spent hydrogenation catalyst powder.
  17. 17. The method of claim 16, wherein the waste hydrogenation catalyst is wet crushed under the protection of heavy oil and then added.
  18. 18. The method of claim 1, wherein the ebullated bed hydrogenation reactor is operated in a partial recycle mode of the discharged heavy coal tar to maintain the ebullated state of the microspherical catalyst or microspherical inert packing.
  19. 19. The method according to claim 18, wherein the ebullated bed hydrogenation reactor has a liquid hourly space velocity of 0.1 to 10 h -1 based on the liquid phase excluding the recycled amount of the discharged heavy coal tar.
  20. 20. The method according to claim 19, wherein the ebullated bed hydrogenation reactor has a liquid hourly space velocity of 0.4 to 3 h -1 based on the liquid phase excluding the recycled amount of the discharged heavy coal tar.

Description

Raw gas heat recovery and coal tar pretreatment device and application Technical Field The invention belongs to the technical field of preparing liquid hydrocarbon mixtures and coal gas from coal, and relates to a raw gas heat recovery and coal tar pretreatment device and application. Background The energy resource types of China are unevenly distributed, and the method is characterized by being rich in coal, oil-deficient and gas-deficient, namely, the coal resources are rich, account for 94.3% of the fossil energy exploration reserves, and the total consumption of the primary energy reaches about 70%. Among the abundant coal resources, the low-rank coal reserves are the largest and account for 55% of the established reserves. In the utilization of low rank coal, it is difficult to directly use as fuel, but it is a good quality feedstock for the production of liquid hydrocarbons from coal. The preparation of liquid hydrocarbon from low-rank coal has two main routes, namely a direct coal liquefaction technology, and the cost is high. The other is a coal carbonization/coking technology, the basic principle is the pyrolysis reaction of low-rank coal, and the technology is simple and mature, the obtained coke or semicoke is a high-quality fuel and raw materials such as reducing agents required by the metallurgical industry, and meanwhile, liquid hydrocarbon (namely coal tar) is obtained, and the further processing can be used for producing liquid fuel and various chemical raw materials. In the carbonization/coking process of coal, the discharged raw gas has higher temperature, which can reach more than 600 ℃ generally and accounts for about 37 percent of the heat of a coke oven, and the raw gas has complex composition and contains solid coke powder, mixed hydrocarbon with complex composition, gas phase, water with complex composition and the like. Although the gas has abundant heat, the heat is difficult to recycle, and the main problems are blockage, coking, corrosion and the like of heat exchange equipment. In the traditional technology, ammonia water is adopted for spraying and cooling, heat in the ammonia water is totally lost, and the energy consumption of the device is large. Therefore, how to effectively recover heat in raw gas, especially how to solve the problems of equipment blockage, coking and the like when recovering heat, is a major concern in the field. CN 201310391012.7 discloses a coke oven raw gas waste heat recycling system, which comprises a heat exchange medium circulation system and a water supplementing system, wherein the heat exchange medium circulation system comprises a heat exchanger group, a steam drum and a forced circulation pump, a water inlet of the heat exchanger group is connected with a water outlet of the steam drum through the forced circulation pump, a water outlet of the heat exchanger group is connected with a water inlet of the steam drum, a steam outlet on the steam drum is connected with an external steam pipe network, the water supplementing system comprises a buffer water tank, a water supplementing pump, a water feeding pump and a desalting and deoxidizing water tank, the water feeding pump is arranged between the buffer water tank and the desalting and deoxidizing water tank, and the buffer water tank is connected with the steam drum through the water supplementing pump. According to the scheme, the plurality of heat exchanger groups connected in parallel are arranged, the control system is additionally arranged, the quantity of the heat exchanger groups in time is detected when a certain heat exchanger group fails, the safety and the reliability of the heat exchange system are improved, the safety and the normal operation of the system are improved, and the accident rate is reduced. However, in view of the characteristics of raw gas, coking and scaling of the heat exchanger groups must occur rapidly, and even if a parallel connection mode is adopted, larger fluctuation and operation difficulty are brought to normal operation when one group is maintained. CN201410692354.7 discloses a system and method for pyrolysis raw gas dust removal and oil cooling tar recovery, comprising a particle dust remover, an electric dust removing device, a tar refining tower, a gas cooling tower and an electric tar precipitator which are connected in sequence. The invention provides a novel heat recovery process and method for pyrolysis raw gas cooling and tar recovery refining systems, which is characterized in that a tar refining tower is arranged between a particle bed dust remover and a gas cooling tower, the self heat of the gas is fully utilized, the collected tar is further dehydrated and refined through a rectification principle, the process flow is short, the moisture content of the obtained tar is low, and the quality is good. However, in the scheme, the modes of a particle dust remover, an electric dust removing device and the like are adopted, so that the raw gas which is