CN110283609B

CN110283609B - Pyrolysis-coking combined process and system for preparing coal tar by pyrolyzing pulverized coal

Info

Publication number: CN110283609B
Application number: CN201910418918.0A
Authority: CN
Inventors: 宋佰盈
Original assignee: Individual
Current assignee: Guohua Mingda Energy Technology Co.,Ltd.
Priority date: 2019-05-20
Filing date: 2019-05-20
Publication date: 2021-06-08
Anticipated expiration: 2039-05-20
Also published as: CN110283609A

Abstract

The invention provides a process for preparing coal tar by pyrolyzing pulverized coal, which utilizes a gaseous medium generated by high volatile components of low-rank coal to spontaneously generate a fluidization phenomenon, so that the power consumption of pyrolysis fluidization is effectively reduced, a combined reaction process of fluidized pyrolysis and heavy oil coking is carried out in a reactor, most impurities in the coal tar are solidified in coke and part of light oil products are generated while the heavy oil is coked to generate coke tar, so that the functions of pyrolysis-produced tar and heavy oil coking are combined, the process route is greatly shortened, the product quality is greatly improved, the yield of the coal tar is greatly improved, the dust content in the coal tar is reduced, the subsequent oil products are easier to hydrogenate and upgrade, the added value of the product is greatly improved, and the process is suitable for industrial large-scale production. The product of the invention not only is coal tar produced by common coal pyrolysis, but also comprises coking gasoline, coking diesel oil and coking wax oil, and a large amount of methane and light hydrocarbon products such as C2, C3 and the like are byproducts.

Description

Pyrolysis-coking combined process and system for preparing coal tar by pyrolyzing pulverized coal

Technical Field

The invention belongs to the technical field of coal tar preparation by pulverized coal pyrolysis, relates to a process and a system for preparing coal tar by pulverized coal pyrolysis, and particularly relates to a pyrolysis-coking combined process and a pyrolysis-coking combined system for preparing coal tar by pulverized coal pyrolysis.

Background

With the development of economy, the energy demand in the world is increasing, and the reserves of resources such as petroleum and coal are decreasing and deteriorating. China proves that the coal reserves account for 94% of the total energy, the petroleum accounts for 2.73%, and the natural gas accounts for only 3.05%. In recent years, the dependence of China on foreign oil is continuously improved, the dependence of China on foreign oil in 2018 reaches 69.8%, and the dependence of China on foreign oil in 2019 is expected to reach 71.7%. The basic pattern of energy production and energy consumption mainly based on coal in China is fundamentally determined not to change in a long time. The resources rich in coal and less in oil determine the maintenance of energy safety and national benefits, and the good coal resources are fully utilized, especially the rich-oil coal which occupies half of the reserves.

The low-rank coal in China is mainly distributed in western regions such as Nemeng, Shaanxi, Xinjiang and the like, the western coal resources account for 90.1 percent of the whole country, particularly the coal resources of four provinces of Jinzhong, Shaanxi, Mongolian and Ning in the middle and upstream of the yellow river account for 67 percent of the whole country, and the low-rank coal format oil production is generally between 6 percent and 18 percent and is about 10 percent on average. About 40 hundred million tons of coal are consumed in China every year, wherein about 19 hundred million tons of low-rank coal exist, the total coal consumption amount is 13.3% of coking, 9.2% of coal chemical industry and about 71.8% of direct combustion. The direct combustion part consists of 50.6 percent of coal-fired power generation, 13.8 percent of industrial boiler and 7.4 percent of industrial kiln. Wherein 90% of the low-rank coal is utilized by adopting a direct combustion mode. About 1.9 million tons of coal tar raw materials are burnt, about 4 Daqing oil production quantities are lost, and the waste is serious.

The existing pyrolysis process mainly takes low-rank lump coal as a raw material, and with the development of a fully mechanized mining technology, the proportion of pulverized coal is increased, and the utilization rate of the raw material is low; the oil yield is generally 40-50% of the oil content of the Gejin, and the yield is lower; meanwhile, the device has the advantages of 10 ten thousand tons per year of treatment capacity and small scale; the raw gas has low effective components, high nitrogen content and low heat value; the environmental protection performance and the labor sanitary condition are poor, and the elimination is urgently needed. Therefore, the national energy agency of 2 months in 2017 issues a main task (three) of ' thirteen five ' planning for coal deep processing industry demonstration ', and the content of low-rank coal quality-based utilization is as follows: the research and development of clean and efficient low-rank coal pyrolysis technology overcomes the difficult problems of pulverized coal pyrolysis and gas-liquid-solid separation, develops megaton-level industrial demonstration, and researches new-generation technologies such as fast pyrolysis, catalytic (activation) pyrolysis, pressurized pyrolysis, hydropyrolysis and the like with higher oil product yield. The organic integration of pyrolysis, gasification and combustion is enhanced, the pyrolysis-gasification integrated technology and the pyrolysis-combustion integrated technology are developed, and the joint production demonstration of tar and electric power is developed by matching with a medium-low heat value gas turbine or a coal-fired boiler adapted to reconstruction.

However, various pulverized coal pyrolysis processes developed at present do not solve the problem of separation of coal tar and coke dust well, so that a large amount of produced coal tar is adsorbed in the coke dust, and therefore, the actual coal tar product yield is low, a pipeline is easy to block, the operation period of the device is short, and industrial production is very immature.

Therefore, how to provide a proper pulverized coal pyrolysis process, which solves the problem of separation of coal tar and coke dust, improves the yield of the coal tar, and solves the problems encountered in actual production, has become one of the problems to be solved urgently for a plurality of coal processing enterprises in the industry.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a process and a system for preparing coal tar by pyrolyzing pulverized coal, and in particular, to provide a pyrolysis-coking combined process and a pyrolysis-coking combined system for preparing coal tar by pyrolyzing pulverized coal. According to the pyrolysis-coking combined process provided by the invention, the heavy oil, the powdery low-order oil-rich coal, the oil shale and other raw materials are subjected to fast pyrolysis and heavy oil coking to produce light oil products and chemical raw materials, the yield of the coal tar is improved, the dust content in the coal tar is reduced, the subsequent oil product hydrogenation upgrading and the like are easier, the added value of the product is greatly improved, meanwhile, the process route is greatly shortened, and the process is suitable for industrial mass production.

The invention provides a process for preparing coal tar by pyrolyzing pulverized coal, which comprises the following steps:

1) under the action of fluidizing gas, performing pyrolysis reaction on pulverized coal and hot semicoke to obtain a mixture of oil gas and semicoke;

2) performing pyrolysis coking on the mixture obtained in the step, adding coal tar containing coke dust in the pyrolysis coking process, continuing the pyrolysis coking, and performing gas-solid separation to obtain oil gas containing fine dust;

3) mixing coal tar with the oil gas containing the fine dust obtained in the step, and terminating the coking reaction to obtain uncondensed oil gas;

4) and washing the uncondensed oil gas obtained in the step to obtain gaseous coal tar.

Preferably, the particle size of the pulverized coal is less than or equal to 8 mm;

the temperature of the hot semicoke is 650-1000 ℃;

the mass ratio of the pulverized coal to the hot semicoke is 1: (2-16);

the temperature of the pyrolysis reaction is 480-650 ℃;

the pyrolysis reaction time is 1-5 seconds;

the pressure of the pyrolysis reaction is 10 KPa-3 MPa;

the oil gas comprises high-dust-content gas coal tar;

the fluidizing gas comprises one or more of hydrogen, carbon monoxide, methane, carbon dioxide, nitrogen, hydrogen sulfide, and ammonia.

Preferably, the pyrolytic coking comprises coal pyrolysis, oil shale pyrolysis and oil product coking;

the mode of adding the coal tar containing the coke dust is specifically that the atomized coal tar containing the coke dust is adopted for spraying in the process of pyrolysis and coking;

the adding amount of the coal tar containing the coke dust is less than or equal to 18 percent;

the dust content of the coal tar containing the coke dust is less than or equal to 15 percent;

the time of pyrolysis coking is 1-5 minutes;

the temperature of the pyrolysis coking is 480-650 ℃;

the pressure of the pyrolysis coking is 10 KPa-3 MPa;

the oil gas also comprises one or more of hydrogen, carbon monoxide, methane, carbon dioxide, nitrogen, light hydrocarbon substances, hydrogen sulfide and ammonia.

Preferably, after the oil-containing semi-coke formed in the pyrolysis coking process is fluidized and crushed, the oil-containing semi-coke is combusted in an oxygen-containing atmosphere to obtain hot semi-coke;

the oil content of the oil-containing semi-coke is less than or equal to 1 percent;

the fluidized gas for fluidized crushing comprises hydrogen-containing pyrolysis gas and steam;

the particle size of the fluidized crushing is less than or equal to 8 mm;

the combustion temperature is 650-1000 ℃;

pulverized coal is also added in the combustion process;

fine coke powder is also added in the gas-solid separation process;

the fine coke powder is obtained by separating flue gas formed in the combustion process.

Preferably, the dust-oil ratio in the oil gas containing the fine dust is (0.5-10): 100, respectively;

the temperature for terminating the coking reaction is 380-450 ℃;

the coal tar in the step 3) is medium coal tar obtained in the washing process;

the dust content of the medium coal tar is less than or equal to 0.5 percent;

the mixing in step 3) further comprises steam;

a foam washing step is also included after the step 3);

specifically, the uncondensed oil gas and the coal tar containing the coke dust are in countercurrent contact for foam washing;

the dust-oil ratio of the uncondensed oil gas after foam washing is less than or equal to 0.5 percent;

the washing is specifically to circularly wash the medium coal tar obtained in the washing process;

the dust-oil ratio of the gaseous coal tar is less than or equal to 0.08%.

The invention also provides a system for preparing coal tar by pyrolyzing the pulverized coal, which comprises a riser pyrolysis reactor;

the pyrolysis coking reactor is connected with the outlet of the riser pyrolysis reactor;

a cyclone separator is arranged at the top of the pyrolysis coking reactor;

a cooling scrubber connected to the outlet of the cyclone;

the connecting pipeline of the cyclone separator and the cooling washing tower is connected with the outlet end of a coal tar cooling pipeline;

and the gaseous coal tar storage and recovery system is connected with the gas phase outlet of the cooling washing tower.

Preferably, the riser pyrolysis reactor comprises one or more of a single riser pyrolysis reactor, a dual riser pyrolysis reactor, and a multi-riser pyrolysis reactor;

the system further comprises a pulverized coal feed system and/or a mixer;

the pulverized coal raw material feeding system comprises a raw material processing system, a pulverized coal bin, a feeding tank and a feeder;

and the outlet of the pulverized coal raw material feeding system is connected with the solid raw material inlet of the riser pyrolysis reactor, or is connected with the solid raw material inlet of the riser pyrolysis reactor through a mixer.

Preferably, a plurality of spraying devices are arranged in the pyrolysis coking reactor;

the spraying device is arranged at the dense-phase section and/or the dilute-phase section of the pyrolysis coking reactor;

the spraying device is connected with the bottom of the cooling washing tower;

a fluidized crushing coke quenching section is arranged at the bottom of the pyrolysis coking reactor;

the system also comprises a solid semicoke combustion device and a hot coke storage device connected with the outlet end of the solid semicoke combustion device.

Preferably, the solid semicoke combustion device comprises one or more of a tubular fluidized bed coke burner, a fluidized bed charcoal burner, a fluidized bed gasification furnace and a fluidized bed boiler;

the inlet end of the solid semicoke combustion device is respectively connected with the solid-phase outlet end of the fluidized crushing coke quenching section and the pulverized coal raw material feeding system;

one outlet end of the hot coke storage device is connected with the solid raw material inlet of the riser pyrolysis reactor or is connected with the solid raw material inlet of the riser pyrolysis reactor through a mixer;

the flue gas outlet end at the upper part of the hot coke storage device is connected with a gas-solid separator;

the gas outlet of the gas-solid separator is connected with a flue gas waste heat recovery system;

the solid outlet of the gas-solid separator is communicated with the inlet of the cyclone separator;

the arrangement relationship between the pyrolysis coking reactor and the solid semicoke combustion device and/or the hot coke storage device comprises one or more of high-low parallel arrangement, same-high parallel arrangement and coaxial arrangement.

Preferably, the solid phase outlet end of the fluidized crushing coke quenching section is also connected with a semicoke application storage system;

the other outlet end of the hot coke storage device is connected with the inlet end of the solid semicoke combustion device to form a functional circulation loop;

the inlet end of the coal tar cooling pipeline is connected with the outlet of the quenching oil cooler;

the inlet of the quenching oil cooler is connected with the liquid phase outlet of the lateral line of the cooling washing tower;

the outlet end of a coal tar foam washing pipeline containing coke dust is connected between the outlet end of the coal tar cooling pipeline and the cooling washing tower on a connecting pipeline of the cyclone separator and the cooling washing tower;

and the inlet end of the coal tar foam washing pipeline containing the coke dust is connected with the bottom of the cooling washing tower.

The invention provides a process for preparing coal tar by pyrolyzing pulverized coal, which comprises the following steps of firstly, obtaining a mixture of oil gas and semicoke after the pulverized coal and hot semicoke are subjected to pyrolysis reaction under the action of fluidizing gas; then carrying out pyrolysis coking on the mixture obtained in the step, adding coal tar containing coke dust in the pyrolysis coking process, continuing the pyrolysis coking, and carrying out gas-solid separation to obtain oil gas containing fine dust; mixing the coal tar with the oil gas containing the fine dust obtained in the step, and terminating the coking reaction to obtain uncondensed oil gas; and finally, washing the uncondensed oil gas obtained in the step to obtain the gaseous coal tar. Compared with the prior art, the invention does not well solve the problem of separation of coal tar and coke dust aiming at the existing pulverized coal pyrolysis process, so that the produced coal tar is greatly adsorbed in the coke dust, thereby causing the defects of low yield of coal tar products, easy pipeline blockage in the process, short running period of the device and the like.

The invention integrates the technologies of catalytic cracking, fluid coking and the like in the pyrolysis process, creatively utilizes the gaseous medium generated by high volatile components of low-rank coal to spontaneously generate the fluidization phenomenon, the power consumption of pyrolysis fluidization is effectively reduced, the process for preparing coal tar by pyrolyzing the pulverized coal provided by the invention, the combined reaction process of fluidized pyrolysis and heavy oil coking is carried out in the reactor, when the heavy oil is coked to generate coke and remove coke dust, most of the impurities in the coal tar are solidified in the coke, and part of light oil products are generated, therefore, the functions of tar production by pyrolysis and heavy oil coking are combined into one, the process route is greatly shortened, the product quality is greatly improved, the yield of the coal tar is greatly improved, the dust content in the coal tar is reduced, the subsequent oil product hydrogenation and quality improvement are easier, the added value of the product is greatly improved, and the method is suitable for industrial mass production. The product of the invention not only is coal tar produced by common coal pyrolysis, but also comprises coking gasoline, coking diesel oil and coking wax oil, and simultaneously produces a large amount of methane and light hydrocarbon products such as C2, C3 and the like.

Experimental results show that when typical Shenmu pulverized coal is treated by the process for preparing coal tar by pyrolyzing the pulverized coal, the total yield of the coal tar is 9.72 percent of the mass of raw materials and the dust content in oil is 0.04 percent when the yield of the coal tar is 12 percent by carrying out Gejin analysis on the Shenmu pulverized coal as a raw material. Compared with the slow pyrolysis of lump coal, the oil yield is improved by 140.9 percent, the heat value of pyrolysis gas is improved by 237.9 percent, and the solid content in coal tar is only 8 percent of the basic requirement of the prior art of the lump coal.

Drawings

FIG. 1 is a schematic view of a pyrolysis-coking combined system for preparing coal tar by pyrolyzing pulverized coal according to the present invention.

Detailed Description

For a further understanding of the invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are included merely to further illustrate the features and advantages of the invention and are not intended to limit the invention to the claims.

All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.

All the raw materials of the invention are not particularly limited in purity, and the invention preferably adopts industrial purity or conventional purity required by raw materials of pulverized coal pyrolysis process.

All the raw materials, the marks and the acronyms thereof belong to the conventional marks and acronyms in the field, each mark and acronym is clear and definite in the field of related application, and the raw materials can be purchased from the market or prepared by a conventional method by the technical staff in the field according to the marks, the acronyms and the corresponding application.

All the processes of the invention, the abbreviations thereof belong to the common abbreviations in the art, each abbreviation is clear and definite in the field of its associated use, and the ordinary process steps thereof can be understood by those skilled in the art from the abbreviations.

The invention firstly carries out pyrolysis reaction on pulverized coal and hot semicoke under the action of fluidizing gas to obtain a mixture of oil gas and semicoke.

The definition and specific selection of the fluidizing gas are not particularly limited in principle, and the fluidizing gas can be selected and adjusted by those skilled in the art according to the actual production conditions, raw material conditions and product requirements, so that the coal tar production effect by pyrolysis can be better ensured, the coal tar yield can be improved, and the dust content in the coal tar can be reduced. In the present invention, in particular, a fluidizing gas is added, which has the effect of suspending the solid particles in motion, so that the particles have certain apparent characteristics of a fluid, which is more favorable for the pyrolysis reaction.

The invention has no special limitation on the specific selection and parameters of the pulverized coal in principle, and a person skilled in the art can select and adjust the pulverized coal according to the actual production condition, the raw material condition and the product requirement. The particle size of the pulverized coal is preferably not more than 8mm, more preferably not more than 7mm, more preferably not more than 5mm, more preferably not more than 3mm, specifically 0.01-5 mm, also 0.01-3 mm, or 0.02-1 mm.

The definition and specific selection of the hot semicoke are not particularly limited in principle, and a person skilled in the art can select and adjust the hot semicoke according to actual production conditions, raw material conditions and product requirements, so that the effect of preparing coal tar by pyrolysis is better ensured, the yield of the coal tar is improved, and the dust content in the coal tar is reduced, wherein the temperature of the hot semicoke is preferably 650-1000 ℃, more preferably 700-950 ℃, more preferably 750-900 ℃, and more preferably 800-850 ℃. In the invention, the semicoke is semi-coke, while the hot semicoke not only can be recycled as a recycling reactant, but also has high temperature, and can be used as a heat carrier to enter a system to realize the recycling of heat, and particularly, the fluidized gas is added, so that the solid particles can be suspended in a moving state, and the particles have certain apparent characteristics of fluid and are more favorable for the pyrolysis reaction.

In the invention, the adding amount of the hot semicoke is not particularly limited in principle, and a person skilled in the art can select and adjust the adding amount according to the actual production condition, the raw material condition and the product requirement, so that the invention can better ensure the effect of preparing the coal tar by pyrolysis, improve the yield of the coal tar and reduce the dust content in the coal tar, and the mass ratio of the pulverized coal to the hot semicoke is preferably 1: (2-16), more preferably 1: (4-14), more preferably 1: (6-12), more preferably 1: (8-10).

The invention has no particular limitation on the source of the hot semicoke in principle, and a person skilled in the art can select and adjust the hot semicoke according to the actual production condition, the raw material condition and the product requirement.

The specific conditions of the pyrolysis reaction are not particularly limited in principle, and a person skilled in the art can select and adjust the conditions according to actual production conditions, raw material conditions and product requirements, so that the effect of preparing coal tar by pyrolysis is better ensured, the yield of the coal tar is improved, the dust content in the coal tar is reduced, and the temperature of the pyrolysis reaction is preferably 480-650 ℃, more preferably 510-620 ℃, more preferably 540-590 ℃, and more preferably 550-580 ℃. The time of the pyrolysis reaction is preferably 1 to 5 seconds, more preferably 1.5 to 4.5 seconds, more preferably 2 to 4 seconds, and more preferably 2.5 to 3.5 seconds. The pressure of the pyrolysis reaction is preferably 10KPa to 3MPa, more preferably 50KPa to 0.6MPa, and more preferably 0.1 to 0.3 MPa.

After the pyrolysis reaction, the mixture of oil gas and semicoke is obtained. In the invention, the oil gas contains coal tar with high dust content, namely, the oil gas contains high dust content gas coal tar, and because the pyrolysis process of the pulverized coal is a complex reaction process, the oil gas preferably also contains one or more of hydrogen, carbon monoxide, methane, carbon dioxide, nitrogen, light hydrocarbon substances, hydrogen sulfide and ammonia, and more preferably contains a plurality of hydrogen, carbon monoxide, methane, carbon dioxide, nitrogen, light hydrocarbon substances, hydrogen sulfide and ammonia. The specific dust-to-oil ratio of the high-dust content gaseous coal tar is not particularly limited in the present invention, and can be determined by the conventional dust-to-oil ratio well known to those skilled in the art, and the relevant data are related to the coal quality and the process. In the prior art, the specific dust-oil ratio of the high-dust-content gaseous coal tar is difficult to define, and in the conventional pulverized coal pyrolysis process, the dust-oil ratio of the high-dust-content gaseous coal tar is still as high as 20% -50% after sedimentation and cyclone, so that the dust-oil ratio of the high-dust-content gaseous coal tar is about more than 50%.

And then carrying out pyrolysis coking on the mixture obtained in the step, adding coal tar containing coke dust in the pyrolysis coking process, continuing the pyrolysis coking, and carrying out gas-solid separation to obtain oil gas containing fine dust.

The invention has no particular limitation on the specific definition and conditions of the pyrolytic coking in principle, and a person skilled in the art can select and adjust the specific definition and conditions according to the actual production condition, the raw material condition and the product requirement. The temperature of the pyrolysis coking is preferably 480-650 ℃, more preferably 510-620 ℃, more preferably 540-590 ℃, and more preferably 550-580 ℃. The time of the pyrolysis coking is preferably 1-5 minutes, more preferably 1.5-4.5 minutes, more preferably 2-4 minutes, and more preferably 2.5-3.5 minutes. The pressure of the pyrolysis coking is preferably 10KPa to 3MPa, more preferably 50KPa to 0.6MPa, and more preferably 0.1 to 0.3 MPa.

The specific parameters of the coal tar containing the coke dust are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production situation, the raw material situation and the product requirement, in order to better ensure the effect of preparing the coal tar by pyrolysis, improve the yield of the coal tar and reduce the dust content in the coal tar, the adding amount of the coal tar containing the coke dust is preferably less than or equal to 18%, more preferably less than or equal to 15%, more preferably less than or equal to 13%, more preferably less than or equal to 11%, and particularly can be 1% -10%. The dust content of the tar containing the tar is preferably 15% or less, more preferably 13% or less, more preferably 11% or less, and specifically may be 1% to 10%.

The specific mode for adding the coal tar containing the coke dust is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the raw material condition and the product requirement. And in the process of pyrolysis and coking, atomized coal tar containing coke dust is adopted for spraying. The atomization according to the invention is preferably carried out by means of steam atomization.

The specific source of the coal tar containing the coke dust is not particularly limited in principle, and a person skilled in the art can select and adjust the source according to the actual production condition, the raw material condition and the product requirement.

The specific conditions for continuously carrying out the pyrolysis coking are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the raw material condition and the product requirement.

The invention has no special limitation on the concrete mode and conditions of the gas-solid separation in principle, and a person skilled in the art can select and adjust the gas-solid separation according to the actual production condition, the raw material condition and the product requirement.

The invention is a complete and refined flow process, improves the yield of coal tar, reduces the dust content in the coal tar, improves the utilization rate of raw materials, and preferably adds fine coke powder in the gas-solid separation process. The fine coke powder is preferably obtained by separating flue gas formed in the combustion process.

In the invention, the fine coke powder returning function is used for heating and circulating combustion of the heat carrier during driving; when the pyrolysis and pyrolysis coking circulation of the device is interrupted, the normal operation and supply of a heat carrier are kept for a short time, and a safe buffer period is provided for the recovery of the operation; meanwhile, the fine coke dust is bulk particles with certain hardness, which is beneficial to the blockage prevention and the removal of viscous oil and coke of the gas-solid separation device, and further ensures the long-term stable operation of the process.

In the invention, the gas after flue gas separation enters a subsequent flue gas waste heat recovery process, and the gas after flue gas separation can be used as waste heat steam, a raw material drying heat source and the like through the flue gas waste heat recovery process; then the waste gas is discharged into the atmosphere after dust removal, desulfurization and the like reach the national emission standard.

In order to better ensure the effect of preparing the coal tar by pyrolysis, improve the yield of the coal tar, reduce the dust content in the coal tar and improve the integrity and the cyclic utilization rate of the whole process, the oil-containing semicoke formed in the pyrolysis and coking process is subjected to fluidization and crushing and then is combusted in an oxygen-containing atmosphere to obtain hot semicoke, namely fluidized back-mixed hot semicoke. The hot semicoke formed in the steps can be used as fluidized back-mixed hot semicoke, can be directly put into a warehouse for application, and can be used as a semi-coke finished product after the system generates excessive semicoke and hot semicoke (heat carrier) and is cooled; the system can also directly supply the hot semicoke to the fluidized gasification furnace as gasification raw material.

The invention is not particularly limited to the specific parameters and conditions of the hot semicoke forming process in principle, and those skilled in the art can select and adjust the parameters according to the actual production conditions, raw material conditions and product requirements, and in order to better ensure the effect of preparing coal tar by pyrolysis, improve the yield of the coal tar and reduce the dust content in the coal tar, the oil content of the oil-containing semicoke is preferably less than or equal to 1%, more preferably less than or equal to 0.8%, more preferably less than or equal to 0.5%, more preferably less than or equal to 0.3%, and particularly may be 0.01% -0.10%. The fluidizing gas for fluidized breaking according to the present invention preferably comprises a hydrogenous pyrolysis gas, which is preferably generated by a pyrolysis reaction, and steam. The particle size of the fluidized crushing is preferably not more than 8mm, more preferably not more than 7mm, more preferably not more than 5mm, more preferably not more than 3mm, specifically 0.01-5 mm, also 0.01-3 mm, or 0.02-1 mm. The combustion temperature of the invention is preferably consistent with the self temperature of the hot semicoke, and is preferably 650-1000 ℃, more preferably 700-950 ℃, more preferably 750-900 ℃, and more preferably 800-850 ℃.

In the invention, the temperature range of the pyrolysis-coking reactor is preferably between 480 and 650 ℃, and pyrolysis and coking reactions can be simultaneously carried out in the temperature range, so that the aim of producing more light oil products is fulfilled; the temperature of the riser fast pyrolysis reactor, the tubular coke burner and the hot coke storage bin is adapted to the temperature of the pyrolysis coking reactor, wherein the temperature of the riser fast pyrolysis reactor is preferably 20-100 ℃ higher than that of the pyrolysis coking reactor; the temperature of the tubular coke burner and the hot coke storage bin is required to meet the requirement of pyrolysis heat supply, and the temperature range is 650-1000 ℃.

The invention is a complete and refined flow process, improves the yield of coal tar, reduces the dust content in the coal tar, improves the utilization rate of raw materials, and adds pulverized coal in the combustion process. In the invention, the pulverized coal is required to be added when the system is started, is used for the heating of the system and the establishment function of the fluidized heat carrier, and can not be added during normal production.

After the pyrolysis coking and the gas-solid separation, the oil gas containing the dust is obtained in the gas phase, and the coke blocks on the solid phase are continuously circulated in the pyrolysis coking process.

The specific parameters of the oil gas containing the micro dust are not particularly limited in principle, and the production process can be selected and adjusted according to the actual production condition, the raw material condition and the product requirement by a person skilled in the art, so that the effect of preparing the coal tar by pyrolysis is better ensured, the yield of the coal tar is improved, and the dust content in the coal tar is reduced, wherein the dust-oil ratio (namely the dust content) in the oil gas containing the micro dust is preferably (0.5-10): 100, more preferably (2.5 to 8): 100, more preferably (4.5-6): 100. in the present invention, the dust-oil ratio or dust content in the oil gas preferably refers to the mass ratio of the coke dust solid phase and the liquid oil phase after the oil gas is condensed at normal temperature and the solid-liquid phase is separated, which is also referred to as the ratio of the mass of the coke dust solid phase to the mass of the pyrolysis oil.

The invention mixes the coal tar with the oil gas containing the dust obtained in the above step, and then terminates the coking reaction to obtain the uncondensed oil gas.

The specific source of the coal tar is not particularly limited in principle, and a person skilled in the art can select and adjust the source according to the actual production condition, the raw material condition and the product requirement.

The specific parameters of the definition of the medium coal tar are not particularly limited, and a person skilled in the art can select and adjust the parameters according to the actual production condition, the raw material condition and the product requirement.

The specific parameters of the dust content of the medium coal tar are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual production condition, the raw material condition and the product requirement.

The invention has no particular limitation on the specific process and conditions of the mixing in principle, and a person skilled in the art can select and adjust the mixing process according to the actual production situation, the raw material situation and the product requirement.

The specific parameters and conditions of the termination coking reaction are not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual production conditions, raw material conditions and product requirements.

The invention is a complete and refined flow process, better ensures the effect of preparing coal tar by pyrolysis, improves the yield of the coal tar, reduces the dust content in the coal tar, and preferably further comprises a foam washing step after the step 3), namely, the uncondensed oil gas obtained in the step 3) is subjected to foam washing and then enters the step 4).

The specific process and conditions of the foam washing are not particularly limited in principle, and a person skilled in the art can select and adjust the foam washing according to the actual production condition, the raw material condition and the product requirement. The foam wash of the present invention has preferably dynamic wave foam wash.

The coal tar containing the coke dust according to the invention is preferably the coal tar containing the coke dust obtained after the washing process in step 4) has ended. The dust content of the foam scrubbing liquid (coal tar containing coke dust) of the present invention is preferably 18% or less, more preferably 15% or less, more preferably 13% or less, more preferably 11% or less, and specifically may be 1% to 10%. The temperature of the foam washing liquid (coal tar containing coke dust) is preferably 380-450 ℃, more preferably 390-440 ℃, more preferably 400-430 ℃ and more preferably 410-420 ℃. The gas-liquid ratio of the foam washing is preferably 30-180, more preferably 50-160, more preferably 70-140, and more preferably 90-120. The foam washing of the invention greatly improves the washing effect, and the washing efficiency reaches 95-99%.

The invention has no particular limitation on the dust content of the uncondensed oil gas after the foam washing in principle, and the uncondensed oil gas is prepared by referring to the process of the invention by the technical personnel in the field, and the technical personnel in the field can select and adjust the process according to the actual production condition, the raw material condition and the product requirement, so that the invention better ensures the effect of preparing coal tar by pyrolysis, improves the yield of the coal tar and reduces the dust content in the coal tar, and the dust content of the uncondensed oil gas after the foam washing, namely the dust-oil ratio, is preferably less than or equal to 0.5 percent, more preferably less than or equal to 0.3 percent and more preferably less than or equal to 0.1 percent.

Finally, washing the uncondensed oil gas obtained in the step to obtain the gaseous coal tar.

The specific process and conditions of the washing are not particularly limited in principle, and a person skilled in the art can select and adjust the washing according to the actual production situation, the raw material situation and the product requirement.

In the washing process, the medium coal tar can be obtained near the middle part of the washing tower and is used for circularly washing the washing liquid in the washing tower, and simultaneously, the coal tar containing the coke dust obtained at the bottom of the tower can also be used for spraying in the foam washing and pyrolysis coking processes in the process flow after the washing process is finished.

The invention finally sends the washed uncondensed oil gas, namely gaseous coal tar, pyrolysis gas and the like, into a subsequent recovery and separation process system.

The dust content of the gaseous coal tar is not particularly limited in principle, and the gaseous coal tar can be prepared by a person skilled in the art according to the process disclosed by the invention, and the person skilled in the art can select and adjust the gas coal tar according to the actual production condition, the raw material condition and the product requirement.

More particularly preferably, in the invention, the washing liquid phase after being washed by the quenching foam, namely the tower bottom dust-containing tar (tar containing the dust), is generally controlled to have the dust content of less than 10 percent, short time can be more than 10 percent, and the maximum is not more than 20 percent; the medium oil is extracted from the tower plate in the middle of the washing tower, the dust content in the medium coal tar is generally below 0.5 percent, the dust content is the tiny dust in the oil gas gradually washed from the top of the washing tower, and the dust content of the gas coal tar at the outlet of the washing tower is not more than 0.08 percent at most.

The invention provides a pyrolysis-coking combined process for preparing coal tar by pyrolyzing pulverized coal, which is characterized in that powdery low-order raw materials rich in oil coal, oil shale and heavy oil are subjected to combined reaction of fluidized pyrolysis and fluidized coking, so that the problem of oil and coke dust separation which cannot be realized by pyrolysis in the prior art is solved, the yield of oil products is increased, and a processing method for extracting substances such as light oil products, synthesis gas and semicoke from the powdery coal and the oil shale is realized.

a cyclone separator is arranged at the top of the pyrolysis coking reactor;

a cooling scrubber connected to the outlet of the cyclone;

The connection means in the present invention is not particularly limited in principle, and may be any conventional connection means known to those skilled in the art, and may be selected and adjusted by those skilled in the art according to actual production conditions, raw material conditions and product requirements, and the connection means in the present invention is preferably a connection means through a pipe or a connection means through a pipe and a pump. The invention is not particularly limited to the relevant control and monitoring equipment on the pipeline, and those skilled in the art can select and adjust the equipment according to the actual production conditions, raw material conditions and product requirements.

The present invention is in principle not particularly limited as to the choice of the riser pyrolysis reactor and its specific structure, the invention is a complete and refined process device system, better ensures the long-term stable operation of the system, improves the yield of the coal tar, reduces the dust content in the coal tar, improves the cyclic utilization rate of the system, the riser pyrolysis reactor preferably comprises one or more of a single-riser pyrolysis reactor, a dual-riser pyrolysis reactor, and a multi-riser pyrolysis reactor, more preferably a single-riser pyrolysis reactor, a dual-riser pyrolysis reactor, or a multi-riser pyrolysis reactor, and more preferably a single-riser pyrolysis reactor. In the present invention, the riser (fast) pyrolysis reactor is preferably a transfer pipe and a pyrolysis reaction zone which are formed by lining a metal pipe with a refractory lining in specific structures.

In the invention, the riser of the riser reactor can enter the reactor from the bottom center of the pyrolysis coking reactor, and also can enter from the side surface of the bottom of the pyrolysis coking reactor, so that a spouted bed is formed in the center of the reactor.

The invention relates to a complete and refined process device system, which better ensures the long-term stable operation of the system, improves the yield of coal tar, reduces the dust content in the coal tar and improves the recycling utilization rate of the system.

The pulverized coal raw material feeding system preferably comprises a raw material processing system, a pulverized coal bin, a feeding tank and a feeding machine, and more preferably comprises the raw material processing system, the pulverized coal bin, the feeding tank and the feeding machine which are sequentially connected. The feeder is used as an outlet of a pulverized coal raw material feeding system.

In the present invention, the outlet of the pulverized coal raw material feeding system is connected to the solid raw material inlet of the riser pyrolysis reactor, or is connected to the solid raw material inlet of the riser pyrolysis reactor through a mixer, and more preferably is connected to the solid raw material inlet of the riser pyrolysis reactor through a mixer, so as to provide a more suitable pulverized coal raw material and a more stable feeding system. In other technical schemes, the connection mode can be other modes, and a more suitable pulverized coal raw material and a more stable feeding system are provided as an optimization scheme.

In the invention, the system for preparing coal tar by pyrolyzing pulverized coal comprises a pyrolysis coking reactor connected with the outlet of the riser pyrolysis reactor. The invention is a complete and refined process device system, which better ensures the long-term stable operation of the system, improves the yield of coal tar, reduces the dust content in the coal tar, and improves the cyclic utilization rate of the system. Preferably, the spraying device is connected with the bottom of the cooling washing tower, is used as a source of liquid phase for spraying, and is also connected with a steam source to provide atomized steam for spraying. Furthermore, the bottom of the pyrolysis coking reactor is preferably provided with a fluidized crushing coke quenching section.

In the present invention, the pyrolysis coking reactor is preferably divided into three zones along the height from bottom to top in the specific structure according to the difference of the function and the flow state: a crushing coke quenching zone (fluidized crushing coke quenching section), a pyrolysis-coking reaction zone (dense phase section) and a dilute phase separation zone (dilute phase section). The crushing and coke quenching area is positioned at the bottommost end of the reactor, and has the functions of gaseous fluidization, steam stripping and coke quenching, and decomposition and crushing of large coke blocks formed by coking. From the lower part of the outlet of the central spray pipe to the bottommost part, the gas is in a bubbling bed state. The pyrolysis-coking reaction zone is divided into a central spraying zone and a peripheral annular back mixing zone from the outlet of the central spraying pipe to the top end of the sprayed material and the top end of the dense-phase zone, and the central gas velocity of the zone is high and the particle concentration is low; the gas velocity of the annular back mixing zone is low, and the particle concentration is high. The top is a dilute phase separation zone which is in a fully mixed state.

In the invention, a cyclone separator is arranged at the top of the pyrolysis coking reactor. The invention is in principle not particularly restricted to the choice of the cyclone and its specific construction, as is customary in the art and known to the person skilled in the art, and can be selected and adapted by the person skilled in the art according to the actual production conditions, the raw material conditions and the product requirements. In the invention, an inlet of the cyclone separator is preferably arranged at the top of the pyrolysis coking reactor, and oil gas generated by pyrolysis coking enters the cyclone separator for gas-solid separation.

More preferably, an oil-gas cyclone separator is arranged in a dilute phase separation zone at the upper part of the pyrolysis coking reactor, the oil-gas-dust mixed material from the pyrolysis-coking zone is subjected to gas-solid separation, the separated solid returns to the reaction zone, the oil gas is rapidly cooled from a rotational separation outlet and then sent to a washing tower, a small amount of semi-coke particles mainly within the range of 30-200 mu m from a fine powder collecting tank of a hot coke storage bin are sprayed from a primary cyclone inlet by taking steam as a medium, and cokes in the rotary drum are cleaned.

In the invention, the fluidized crushing coke quenching section is used as an important component of the pyrolysis coking reactor, namely a stripping coke quenching area at the lower part of the pyrolysis coking reactor, two fluidized media are provided, one is gas containing hydrogen, the other is vapor, a gas introducing point is arranged above a vapor introducing point, the two media play a role of fluidization, the semicoke at the part contains a trace amount of heavy coal tar, the steam stripping has small effect on the coal tar, therefore, the steam mainly plays a coke quenching role here, and the excessive coke is quenched, cooled and discharged out of the system at the part. The coke quenching device has the function of extracting inflammable gas in the semicoke, so that the semicoke finished product semi-coke discharged from the lower part after being cooled does not contain toxic and harmful substances to pollute the environment; the crushing function is to crush the large coke blocks generated by adhesion during the coking reaction in a fluidized boiling state by collision, so that large coke blocks which are easy to block and are not beneficial to fluidization are not generated.

In the invention, in the pyrolysis-coking reactor, the material is sprayed from the outlet of the riser and forms a spouted bed with the material fluidized at the bottom, and slightly large particles which are not completely pyrolyzed in the spouted bed are continuously pyrolyzed; an annular upper portion surrounded by a plurality of layers of nozzles arranged around the reactor; one or more layers of nozzles arranged around the reactor are arranged at the upper part of the central injection zone; the nozzle takes steam as an atomizing medium, the oil slurry containing the coke dust is sprayed into a reaction bed layer, atomized oil drops containing the coke dust are combined with a heat carrier, an oil film is formed on the surface of particles to carry out coking reaction, fine coke dust particles are gradually coked and enlarged by coking, and the purpose of separation is finally realized.

The system is a complete and refined process device system, better ensures the long-term stable operation of the system, improves the yield of the coal tar, reduces the dust content in the coal tar, and improves the recycling utilization rate of the system.

The present invention is not particularly limited in principle to the choice of the solid semicoke burning apparatus and its specific structure, the invention is a complete and refined process device system, better ensures the long-term stable operation of the system, improves the yield of the coal tar, reduces the dust content in the coal tar, improves the cyclic utilization rate of the system, the solid semicoke combustion apparatus preferably includes one or more of a tubular fluidized bed char burner, a fluidized bed gasification furnace, and a fluidized bed boiler, more preferably a tubular fluidized bed char burner, a fluidized bed gasification furnace, or a fluidized bed boiler, and more preferably a tubular fluidized bed char burner (tubular char burner).

In the invention, the tubular coke burner is preferably composed of a bottom fuel mixing section and a coke burning pipe in the specific structure, wherein the fuel mixing section is provided with a semicoke inlet and a fuel gas and air inlet, the coke burning pipe is a conveying pipeline type oxidation burner formed by a metal pipe lining refractory lining, and an outlet is arranged in a hot coke storage device (a hot coke storage bin).

In the invention, the inlet end of the solid semicoke combustion device is preferably respectively connected with the solid-phase outlet end of the fluidized crushing coke quenching section and the pulverized coal raw material feeding system, the aim is to recycle hot semicoke returned by pyrolysis coking as a heat carrier, and the pulverized coal connecting system can provide operation guarantee for the system during starting, short-term stopping or system instability, thereby guaranteeing the long-term stable operation of the whole process system. In other technical schemes, the connection mode can be other modes, and a more suitable powdered coal raw material, hot semicoke, smooth start and stop and a more stable process system are provided as an optimization scheme.

The selection and the specific structure of the hot coke storage device are not particularly limited in principle, and the structure of a conventional pyrolysis coking reactor in the process known by the technical personnel in the field can be used, and the technical personnel in the field can select and adjust according to the actual production condition, the raw material condition and the product requirement.

In the invention, the hot coke storage bin is preferably limited by the bin wall in terms of specific structure, the high-temperature materials from the lining heat-insulating container and the tubular coke burner are subjected to gas-solid settlement separation in the hot coke storage bin, and the solids are stored in the storage bin and used as a heat source for the pyrolysis-coking reaction. More preferably, the hot coke storage bin is a moving bed, the upper wall of the hot coke storage bin is provided with a fine powder collecting tank, and particles separated by a gas-solid separator (coarse cyclone) are collected to be used for cyclone separation of coke cleaning materials of a coking reactor; the lower part is provided with a safe start device which consists of a material return pipe and a slide valve and directly returns the high-temperature semicoke in the hot coke storage bin to the tubular coke burner, so that gas (or liquid) fuel can be saved during start, and the start cost is reduced; when the conditions such as interruption occur in the returned materials, the secondary combustion caused by overhigh oxygen content in the flue gas can be prevented, and the safe operation of the device is influenced.

In the present invention, an outlet end of the hot coke storage device is preferably connected to the solid raw material inlet of the riser pyrolysis reactor, or connected to the solid raw material inlet of the riser pyrolysis reactor through a mixer, and more preferably connected to the solid raw material inlet of the riser pyrolysis reactor through a mixer. The device aims to provide a powerful buffering and guaranteeing device in the process of recycling hot semicoke returned by pyrolysis coking as a heat carrier, can provide operation guarantee for system start-up, short-term shutdown or system instability, and guarantees the long-term stable operation of the whole process system. In other technical schemes, the connection mode can be other modes, so that a more suitable hot semicoke, smooth start and stop and a more stable process system are provided as an optimization scheme.

In the invention, the flue gas outlet end at the upper part of the hot coke storage device is connected with a gas-solid separator or is provided with the gas-solid separator. Further, the gas outlet of the gas-solid separator is preferably connected with a flue gas waste heat recovery system. The gas-solid separator can be a cyclone separator. The device aims to separate the flue gas generated in the semicoke combustion and thermal coke storage processes, and respectively recycle the focusing dust and the heat, so that the overall long-term stable operation of a process system is guaranteed. In other technical schemes, the connection mode and the device can be in other modes, and a more suitable circulating system and a more stable process system are provided as an optimization scheme.

In the present invention, the solid outlet of the gas-solid separator is preferably communicated with the inlet of the cyclone separator, that is, the inlet of the cyclone separator provided at the top of the pyrolysis coking reactor. The cyclone separator is used for a cyclone separator at the top of a pyrolysis coking reactor, can effectively help the cyclone separator to remove internal viscous tar and coke, prevents air channel blockage, reduces the number of times of parking cleaning, can not reduce the temperature of a system, saves heating energy consumption, realizes simultaneous cyclic utilization of focusing dust and heat, provides powerful guarantee, and ensures the integral long-term stable operation of a process system. In other technical schemes, the connection mode and the device can be in other modes, so that a more suitable functional material, smooth start and stop and a more stable process system are provided as an optimization scheme.

In the invention, the excessive hot semicoke can be discharged from the bottom of the pyrolysis coking reactor and the hot coke storage bin, and the temperature of the semicoke in the reactor is lower than that in the hot coke storage bin, so that the semicoke is directly combusted and utilized as a solid fuel, and the discharge from the coke storage bin is preferred; and (3) if the semicoke needs to be cooled, preferably selecting a reactor coke discharging scheme, and reserving a hot coke storage bin coke discharging device for emergency use.

In the invention, the solid phase outlet end of the fluidized crushing coke quenching section is also connected with a semicoke application storage system. The method aims to solve the problems that hot semicoke obtained by a pyrolysis coking reactor can be used as fluidized back-mixed hot semicoke and can also be directly put into a warehouse for application, and meanwhile, when the system generates excessive semicoke and hot semicoke (heat carrier), the hot semicoke can also be used as a semi-coke finished product after being cooled; the system can also directly supply hot semicoke to the fluidized gasification furnace to be used as a gasification raw material, realizes the simultaneous cyclic utilization of blue coke and heat, provides powerful guarantee for the system, can provide operation guarantee for the system during starting, short-term shutdown or instability of the system, and guarantees the long-term stable operation of the whole process system. In other technical schemes, the connection mode and the device can be in other modes, and a more proper thermal semicoke and a more stable process system are provided as an optimized scheme.

In the present invention, the other outlet end of the hot coke storage device is connected with the inlet end of the solid semicoke combustion device. The method aims to form a functional circulation loop by using hot semicoke obtained by a pyrolysis coking reactor as fluidized back-mixed hot semicoke, realize simultaneous cyclic utilization of blue coke and heat, provide powerful guarantee for a system, provide operation guarantee for system start-up, short-term shutdown or system instability and guarantee long-term stable operation of the whole process system. In other technical schemes, the connection mode and the device can be in other modes, and a more proper thermal semicoke and a more stable process system are provided as an optimized scheme.

The present invention is not particularly limited in the arrangement relationship of the pyrolysis coking reactor and the solid semicoke combustion device and/or the hot coke storage device, and the arrangement relationship is not limited in any way, and may be in a conventional arrangement manner on the equipment arrangement known to those skilled in the art, and those skilled in the art can select and adjust the arrangement relationship according to the actual production situation, the raw material situation and the product requirement.

In the invention, the system for preparing coal tar by pyrolyzing pulverized coal comprises a cooling washing tower connected with the outlet of the cyclone separator. The selection and specific structure of the cooling washing tower are not particularly limited in the present invention, and the structure of the cooling washing tower with multiple stages of trays is conventional in the art and is well known to those skilled in the art, and can be selected and adjusted according to actual production conditions, raw material conditions and product requirements.

In the invention, the connecting pipeline of the cyclone separator and the cooling washing tower is connected with the outlet end of a coal tar cooling pipeline, and further, the inlet end of the coal tar cooling pipeline is connected with the outlet of the quenching oil cooler. The purpose is that the oil gas obtained from the gas phase outlet of the cyclone separator can adopt coal tar with lower temperature to stop coking reaction in time. In other technical schemes, the connection mode and the device can be other modes, and a more suitable coal tar raw material for cooling and a more stable process system are provided as an optimization scheme.

In the invention, the inlet of the quenching oil cooler is preferably connected with the liquid phase outlet of the cooling washing tower side line and/or connected with the oil phase outlet at the bottom of the fractionating tower in the subsequent liquid coal tar storage and recovery system, and more preferably connected with the liquid phase outlet of the cooling washing tower side line. The method aims to extract the fraction (medium coal tar) from the middle part of the washing tower which is basically free of dust during washing of the cooling washing tower, the fraction can be used as the circularly cooled coal tar, the impurity interference of foreign phases can be reduced, the advantages of the rest heat temperature can be utilized, the moderate temperature can be obtained, and the medium coal tar and the heat can be simultaneously recycled. In other technical schemes, the connection mode and the device can be other modes, and a more suitable coal tar raw material for cooling and a more stable process system are provided as an optimization scheme.

The invention relates to a complete and refined process device system, which better ensures the long-term stable operation of the system, improves the yield of coal tar, reduces the dust content in the coal tar and improves the recycling utilization rate of the system. The purpose is that the oil gas obtained from the gas phase outlet of the cyclone separator is further washed by foam after the coking reaction is stopped. In other technical schemes, the connection mode and the device can be other modes, and a more suitable coal tar raw material for cooling and a more stable process system are provided as an optimization scheme.

In the invention, the inlet end of the coal tar foam washing pipeline containing the coke dust is preferably connected with the bottom of the cooling washing tower, and is more preferably connected with the bottom of the cooling washing tower through a dynamic wave washing pump, namely the washing of the uncondensed oil gas by the bottom oil of the washing tower is realized by adopting the dynamic wave washing pump. The method aims to wash the foam of the coal tar (heavy) containing the coke dust at the bottom of the washing tower before washing and after stopping coking reaction by using the cooling washing tower, so that the uncondensed oil gas is washed for multiple times in multiple modes, and the coal tar with different dust-containing grades in the system is comprehensively utilized in a gradient manner. The external force coal tar can be saved, the impurity interference of foreign matters can be reduced, the coke dust contained in the coal tar can be further processed and promoted, the coal tar can be used for spraying in the pyrolysis coking process, the maximum application of coke is ensured, the coal tar containing the coke dust and the coke dust can be simultaneously recycled, the system is effectively guaranteed, the operation guarantee can be provided for the system during starting, short-term stopping or instability of the system, and the whole long-term stable operation of the process system is guaranteed. In other technical schemes, the connection mode and the device can be other modes, and a more suitable coal tar raw material for washing and a more stable process system are provided as an optimization scheme.

The invention is a complete and refined process device system, better ensures the long-term stable operation of the system, improves the yield of coal tar, reduces the dust content in the coal tar, and improves the recycling utilization rate of the system, and the washing system can be preferably as follows:

oil gas at a cyclone outlet at the top of the pyrolysis coking reactor is quenched with steam by cooling oil, preferably medium coal tar, to stop coking reaction, and is sent to a washing tower through a large oil-gas pipeline, the large oil-gas pipeline is a metal pipe coated with heat insulation, a large oil-gas pipe vertical pipe is preferably provided with a dynamic wave washing section, washing oil, preferably coal tar containing coke dust, collides with the oil gas in a countercurrent manner to form a foam area for washing the coke dust in the oil gas, and the washed oil gas and the washed oil dust enter the washing tower. Oil slurry (coal tar containing coke dust) consisting of heavy coal tar and washed coke dust is gathered at the bottom of the tower and circularly washed by a washing circulating pump and a foam washing section; the washing tower is internally provided with a spray washing tower plate and a plurality of layers of washing tower plates, and after washing by the washing tower, the dust content in oil gas at the outlet of the washing tower is controlled to be less than one thousandth. The medium coal tar with extremely low coke dust content can be extracted from the multi-layer washing tower plates to be used as the cooling oil. In the present invention, dynamic wave washing is preferably employed to efficiently wash particles of 5 μm or less, and the dynamic wave washing can tolerate a relatively high (20%) solids content without clogging.

In the invention, the system for preparing coal tar by pyrolyzing pulverized coal comprises a gaseous coal tar storage and recovery system connected with a gas phase outlet of the cooling washing tower. The specific composition of the gaseous coal tar storage and recovery system and the connection relationship of the process system are not particularly limited in principle, and the specific composition of the conventional gaseous coal tar storage and recovery system and the connection relationship of the process system on the process known to the technical personnel in the field can be used, and the technical personnel in the field can select and adjust the system according to the actual production condition, the raw material condition and the product requirement. In other technical schemes, the connection mode and the device can be other modes, so that the long-term stable operation of the system is better ensured, the yield of the coal tar is improved, the dust content in the coal tar is reduced, and the circulation utilization rate of the system is improved to be an optimization scheme.

Referring to fig. 1, fig. 1 is a schematic view of a process flow system of a pyrolysis-coking combined system for preparing coal tar by pyrolyzing pulverized coal provided by the invention. Wherein, the coal powder bin (1), the feeding tank (2), the feeding machines (3A/3B) can be substantially the same feeding machine, a burner (4), a tubular coke burning device (5), a hot coke storage bin (6), a flue gas coarse cyclone separator (7), a heat carrier adjusting slide valve (8), a safe start temperature adjusting slide valve (9), a hot coke bin discharging slide valve (10), a mixer (11), a riser fast pyrolysis reactor (12), a pyrolysis coking reactor (13), a fluidization crushing coke quenching section (14), an atomizing nozzle (15), an oil gas cyclone separator (16), a large oil gas pipe (17), a washing tower (18), a reactor discharging slide valve (19), a fine powder collecting tank (20), a coking pump (21), a dynamic wave washing pump (22), a quenching oil pump (23), a main device (24) taking related connecting pipelines of the quenching oil cooler as main parts, a raw material processing system (30), The system comprises an oil gas recovery system (40), a semicoke application and storage system (50) and a flue gas waste heat recovery system (60).

The invention relates to a pyrolysis-coking combined process and a pyrolysis-coking combined system for preparing coal tar by pyrolyzing and refining pulverized coal, which further improve the yield of the coal tar, reduce the dust content in the coal tar, better ensure the long-term stable operation of the system and improve the cyclic utilization rate of the system, wherein the combined process and the system preferably comprise the following steps:

the system provided by the invention specifically comprises a main device mainly comprising a pulverized coal bin (1), a feeding tank (2), a feeding machine (3A/3B) which can be substantially the same feeding machine, a burner (4), a tubular coke burner (5), a hot coke storage bin (6), a flue gas coarse cyclone (7), a heat carrier adjusting slide valve (8), a safe start temperature adjusting slide valve (9), a hot coke bin discharge slide valve (10), a mixer (11), a riser fast pyrolysis reactor (12), a pyrolysis coking reactor (13), a fluidized crushing coke quenching section (14), an atomizing nozzle (15), an oil gas cyclone (16), a large oil gas pipe (17), a washing tower (18), a reactor discharge slide valve (19), a collecting tank fine powder (20), a coking pump (21), a dynamic wave washing pump (22), a quenching oil pump (23) and a quenching oil cooler (24), and related connecting pipelines, A material handling system (30) including screening, drying, storage, etc.; the oil gas recovery system (40) comprises a fractionating tower, a heat exchanger, an air cooler, a compressor and the like; the semi-coke application storage system (50) can be divided into three application methods of semi-coke cooling storage, semi-coke direct combustion heat production and semi-coke direct gasification according to the subsequent use of the semi-coke; the flue gas waste heat recovery system (60) comprises four auxiliary parts, namely a waste heat boiler, an air preheater, a dust remover, a carbon monoxide furnace, a desulphurization device and the like.

Qualified pulverized coal raw materials are processed by a raw material processing system (30), raw materials with the particle size of 0-8 mm (preferably 0-3 mm) are sent into a pulverized coal bin (1) and then are cached in a feeding tank (2), the raw materials are sent to a tubular coke burner (5) by a feeding machine (3A) during starting, the raw materials are sent to a mixer (11) by a feeding machine (3B) or 3A during normal operation, the raw materials controlled by the feeding machine (3B) or 3A) and a heat carrier from a hot coke storage bin (6) controlled by a heat carrier regulating valve (8) enter and are mixed at the upper part of the mixer (11), and the raw materials and the heat carrier enter a riser pyrolysis reactor (12) for pyrolysis under the action of fluidized gas to generate a large amount of oil gas, wherein the oil gas is gas composed of substances such as gaseous tar, carbon monoxide, hydrogen, methane, carbon dioxide, hydrogen sulfide, ammonia and the like. Gas, heat carrier, semicoke and the like are sprayed from the outlet of a lifting pipe (12) and enter a pyrolysis coking reactor (13), the bottom of the reactor (13) takes hydrogen-containing gas as fluidizing gas, steam is the fluidizing gas and stripping steam to ensure that semicoke particles settled by reaction are in a fluidized state, the outer walls of a dense phase section and a dilute phase section of the reactor (13) are provided with a plurality of layers, each layer is uniformly distributed with a plurality of atomizing nozzles (15) around the outer wall, bottom oil containing coke dust from the bottom of a washing tower (18) is sprayed into the reactor (13) by taking the steam as an atomizing medium, oil drops containing the coke dust are atomized and combined with high-temperature fluidized semicoke to form an oil film on the surface of the high-temperature semicoke, wherein, in the process of generating a viscous layer-coke by condensing and coking heavy components such as polycyclic aromatic hydrocarbon, colloid, asphaltene and the like at 480-650 ℃ under a certain pressure, the diameter of fine coke dust particles is increased, and the coking and polymerization of multiple particles are increased; the pyrolysis reaction is continued in the riser (12) without completing the pyrolysis of the slightly larger particles. The fine part of the coke particles washed by the atomized oil and subjected to coking reaction enters an oil-gas cyclone separator (16) at the upper part of the reactor (13) along with pyrolysis oil gas for gas-solid separation, the oil gas containing 0.5-10% of coke dust enters a large oil-gas pipe (17) from the top of the reactor (13), spraying quenching tar and steam from a quenching oil pump (23) through a quenching oil cooler (24) into an inlet of a large oil gas pipe (17), reducing the temperature of the oil gas to 380-450 ℃, stopping coking reaction, pressurizing and spraying tower bottom oil from the bottom of a washing tower (18) into the large oil gas pipe (17) from a vertical pipe part of the large oil gas pipe (17) through a dynamic wave washing pump (22), the oil gas is in countercurrent contact with the oil gas to form foam washing, fine dust in the oil gas is washed, the oil dust and condensed liquid oil enter the bottom of the washing tower (18), the uncondensed oil gas is continuously washed upwards in the washing tower (18), and finally, all the coke dust in the oil gas is washed. The oil gas is discharged from the top of the washing tower (18) to an oil gas recovery system (40) to produce products such as coking wax oil, coking diesel oil, coking gasoline, dry gas and the like.

Under the action of the outlet of the riser (12) and the fluidized gas (containing hydrogen gas and steam) at the bottom of the reactor (13), the coke particles are in a fluidized back-mixing state, and the function realizes the crushing of large blocks of cokes and prevents the blockage of a conveying pipe. After the oil-containing semi-coke passes through the fluidized crushing coke quenching section (14), the semi-coke passes through a semi-coke circulating pipe and is controlled to enter an inlet at the lower part of the tubular coke burner (5) by a semi-coke control slide valve to be in contact with air entering from the bottom for burning, the burning temperature is controlled to be 650-1000 ℃, and the temperature can be adjusted according to the process requirement. The heated hot coke enters a hot coke storage bin (6) from an outlet at the upper part of a tubular coke burner (5), the hot coke is descended to the storage bin (6) under the action of gravity, the flue gas enters a flue gas coarse cyclone (7) from the upper part of the storage bin, the flue gas after being separated from the dust through the flue gas coarse cyclone (7) is sent to a flue gas waste heat recovery system (60), the flue gas at low temperature is used as a heat source for drying raw materials after recovering waste heat and preheating air, and the flue gas is finally treated to reach the emission standard and then is discharged to the atmosphere.

The fine coke powder from the dipleg of the smoke rough cyclone (7) returns to the hot coke storage bin (6), and part of the fine coke powder is stored in a fine powder collecting tank (20) and is sent to the inlet of an oil gas cyclone (16) in the pyrolysis coking reactor (13) through steam (or nitrogen, carbon dioxide and the like) to prevent the oil gas cyclone (16) from coking.

When the material level of the hot coke storage bin (6) is high, controlling coke discharging by using a hot coke bin discharging slide valve (10) or a reactor discharging slide valve (19), and discharging the surplus semicoke to a semicoke cooling storage system (50); the hot coke conveying adopts the low-temperature flue gas after dust removal as conveying gas, and the flue gas after temperature rise is conveyed to raw materials to be dried to be used as a drying heat source.

The safe start temperature-adjusting slide valve (9) is used for raising the temperature of the system by taking fuel gas (or fuel oil) as fuel in the start combustor (4) when the system is started for the first time in a cold state, the feed machine (3A) supplies raw coal to the tubular coke burner (5) step by step after the temperature is raised, the burning raw coal enters the hot coke storage bin (6) and returns to the tubular coke burner (5) through the safe start temperature-adjusting slide valve (9) for circulating combustion, the fuel gas (or fuel oil) is saved, and the start cost is reduced.

When the safe start temperature-adjusting slide valve (9) is operated, the short-time circulating semicoke interruption occurs and the temperature of the hot coke storage bin (6) needs to be raised, the semicoke circulating amount in the tubular coke burner (5) is adjusted, the situation that the oxygen content in the flue gas is too high, the tail part of the flue gas is burnt, the temperature rises, the equipment is burnt out, and the accident is caused to play a safety role is avoided.

The steps of the invention provide a pyrolysis-coking combined process and a pyrolysis-coking combined system for preparing coal tar by pyrolyzing pulverized coal. The invention relates to a device system for converting a pyrolysis-coking combined reaction into a liquid product in a system consisting of a riser fast pyrolysis reactor, a pyrolysis coking reactor, a tubular coke burner, a hot coke storage bin and the like and a connecting pipeline, wherein low-rank pulverized coal and oil shale powder within the range of 0.02-8 mm are used as main raw materials, part of heavy oil is not (or can be) blended, and the raw materials are converted into the liquid product through the pyrolysis-coking combined reaction.

The process and the system for preparing the coal tar by pyrolyzing the pulverized coal preferably utilize a combined fluidized bed and a moving bed (or two fluidized beds) and a combined pyrolysis and coking process device, wherein the combined pyrolysis-coking process device comprises a riser pyrolysis reactor, a preferred spouted fluidized bed (or a common fluidized bed), a tubular coke burner, a preferred moving bed coke storage bin and the like, and raw materials such as heavy oil, powdery low-order oil-rich coal, oil shale and the like are subjected to fast pyrolysis and heavy oil coking to produce light oil products and chemical raw materials. The method is particularly and obviously different from the traditional fluidized coking in the whole flow, the traditional fluidized coking adopts two fluidized beds, and the method mainly comprises a pyrolysis coking reactor (spouted fluidized bed), a riser pyrolysis reactor, a solid semicoke combustion device (tubular coke burner) and a hot coke storage device; the raw materials mainly adopted by the invention are powdery raw materials, namely solid low-rank coal and oil shale, but not liquid raw materials of fluid coking; the traditional fluid coking is coking reaction, but the invention is pyrolysis and coking combined reaction, the riser is pyrolysis reaction, and the reactor is pyrolysis and coking combined reaction; in the specific details, as the traditional fluid coking is that the fluid coking scrubber is arranged at the top of the reactor, while the invention is that the scrubber is preferably introduced below, the cyclone outlet uses rapid cooling to stop the coking reaction, and then the coking reaction is sent to the scrubber after being washed by dynamic wave foam.

The invention integrates the technologies of catalytic cracking, fluid coking and the like in the pyrolysis process, utilizes the gaseous medium generated by high volatile components of low-rank coal to spontaneously generate fluidization, the power consumption of pyrolysis fluidization is effectively reduced, the process for preparing coal tar by pyrolyzing the pulverized coal provided by the invention, the combined reaction process of fluidized pyrolysis and heavy oil coking is carried out in the reactor, when the heavy oil is coked to generate coke and remove coke dust, most of the impurities in the coal tar are solidified in the coke, and part of light oil products are generated, therefore, the functions of tar production by pyrolysis and heavy oil coking are combined into one, the process route is greatly shortened, the product quality is greatly improved, the yield of the coal tar is greatly improved, the dust content in the coal tar is reduced, the subsequent oil product hydrogenation and quality improvement are easier, the added value of the product is greatly improved, and the method is suitable for industrial mass production. The product of the invention not only is coal tar produced by common coal pyrolysis, but also comprises coking gasoline, coking diesel oil and coking wax oil, and simultaneously produces a large amount of methane and light hydrocarbon products such as C2, C3 and the like.

For further illustration of the present invention, the process and system for preparing coal tar by pyrolyzing pulverized coal provided by the present invention will be described in detail with reference to the following examples, but it should be understood that these examples are carried out on the premise of the technical solution of the present invention, and the detailed embodiments and specific procedures are given only for further illustration of the features and advantages of the present invention, and not for limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the following examples.

Example 1

Referring to fig. 1, fig. 1 is a schematic view of a process flow system of a pyrolysis-coking combined system for preparing coal tar by pyrolyzing pulverized coal provided by the invention.

Qualified pulverized coal raw materials are processed by a raw material processing system (30), the raw materials with the particle size preferably ranging from 0 mm to 3mm are sent to a pulverized coal bin (1), cached in a feeding tank (2), sent to a mixer (11) by a feeding machine (3B), and subjected to pyrolysis with a heat carrier at the temperature of 700 +/-20 ℃ from a hot coke storage bin (6) controlled by a heat carrier regulating valve (8), and enter and mix at the upper part of the mixer (11) according to the ratio of the raw materials to the hot coke of 1 (3.5-4.5), the mixing temperature is about 550 +/-10 ℃, the mixture enters a riser pyrolysis reactor (12) for pyrolysis to generate a large amount of pyrolysis oil gas, the oil gas is gas consisting of gaseous tar, carbon monoxide, hydrogen, methane, carbon dioxide, hydrogen sulfide, ammonia and the like, and the residence time of the riser is about 3-5 seconds. Gas, a heat carrier, semicoke and the like are sprayed from an outlet of a lifting pipe (12) and enter a pyrolysis coking reactor (13), the temperature of the reactor (13) is 530 +/-10 ℃, the outer walls of a dense-phase section and a dilute-phase section of the reactor (13) are provided with three layers, 6 atomizing nozzles (15) are uniformly distributed on each layer around the outer wall, tower bottom oil containing coke dust from the bottom of a washing tower (18) is sprayed into the reactor (13) by using steam as an atomizing medium, atomized oil drops containing the coke dust are combined with high-temperature fluidized semicoke to form an oil film on the surface of the high-temperature semicoke, condensation and coking are carried out under the temperature condition of 530 +/-10 ℃ and the pressure of 0.05MPa, and the diameter of fine coke dust particles is increased; an oil gas cyclone separator (16) at the upper part is used for carrying out gas-solid separation, oil gas containing 4.8 percent of coke dust enters a large oil gas pipe (17) from the top of a reactor (13), quenching oil is sprayed into the inlet of the large oil gas pipe (17), the temperature of the oil gas is reduced to 390 +/-5 ℃, the coking reaction is stopped, a vertical pipe of the large oil gas pipe is sprayed into tower bottom oil containing 3 percent of coke dust in a washing tower through a dynamic wave washing pump (22) to form foam washing by countercurrent contact with the oil gas, fine coke dust in the oil gas is washed off, the oil dust and condensed liquid oil enter the bottom of the washing tower (18), uncondensed oil gas continues to be washed upwards in the washing tower (18), and finally the coke dust in the oil gas is completely washed off. The oil gas is discharged from the top of the washing tower (18) to an oil gas recovery system (40) to produce products such as coking wax oil, coking diesel oil, coking gasoline, dry gas and the like.

After the semicoke at 530 +/-10 ℃ passes through a fluidized crushing and coke quenching section (14), the semicoke passes through a semicoke circulating pipe and is controlled to contact and combust with room-temperature air entering from the bottom of an inlet at the lower part of the tubular coke burner (5) by a semicoke control slide valve, and the combustion temperature is controlled to be 700 +/-20 ℃. 700 ℃ hot coke enters a hot coke storage bin (6) from an outlet at the upper part of a tubular coke burner (5), the hot coke is descended to the storage bin (6) under the action of gravity, 700 ℃ flue gas enters a flue gas coarse cyclone (7) from the upper part of the storage bin, the flue gas after being separated from dust through the flue gas coarse cyclone (7) is sent to a flue gas waste heat recovery system (60), the flue gas and preheated air are recovered, the low-temperature flue gas is used as a heat source for drying raw materials, and finally the flue gas is treated to reach the emission standard and then is discharged.

The flue gas coarse cyclone separation (7) is performed with the dipleg of 700 ℃, fine coke powder with the particle size of 30-100 mu m returns to the hot coke storage bin (6), the fine coke powder is partially stored in a fine powder collecting tank (20), the fine coke powder is blown to the inlet of an oil gas cyclone separator (16) in a pyrolysis coking reactor (13) through saturated steam with the pressure of 1.0MPa, fine powder particles are separated through the oil gas cyclone separator (16) and return to the reactor, and coked substances on the inner wall of the cyclone separator are cleaned.

And controlling coke discharging by using a hot coke bin discharging slide valve (10) or a reactor discharging slide valve (19), discharging the surplus semicoke to a semicoke cooler (50), and collecting the cooled semicoke as upgraded fuel coal for sale or other purposes.

The Goldwood coal feedstock used in example 1 of the present invention was subjected to a Gegen pyrolysis analysis. Referring to table 1, table 1 is griffith pyrolysis analysis data for the shenmuke coal feedstock used in example 1 of the present invention.

TABLE 1

The product obtained by the coal tar preparation process by pulverized coal pyrolysis provided by the embodiment 1 of the invention is analyzed and detected. Referring to tables 2 and 3, tables 2 and 3 show the product yield and data analysis obtained in example 1 of the present invention. Wherein, table 2 is a gas quality comparison table, and table 3 is an oil yield and yield comparison table of ton coal.

TABLE 2

TABLE 3 comparison table of products

According to the comparative analysis, when the typical Shenmu powdered coal is processed by the method, and the yield of the tar is 12% in the Shenmu raw material Gejin analysis, the total yield of the coal tar is obtained by the methodThe yield (coking gasoline and coking diesel oil) is 9.72 percent of the mass of the raw material, the dust content in the oil product is 0.04 percent, and the heat value of the pyrolysis gas is 3992KCal/Nm³. Compared with the prior art of slow pyrolysis of lump coal,

referring to the technical requirements of coal tar of the industrial standard YB/T5075-2010, the toluene insoluble substance of the No. 1 product in the table 1 is 3.5-7%, namely, the toluene insoluble substance is a mechanical impurity in the coal tar, and the main component is coke dust.

The detection is according to national standard GB/T2292-2018 determination of toluene insoluble content of coking products

Detection is according to national standard GB/T511-2010 'determination method of mechanical impurities of petroleum and petroleum products and additives'

The oil yield of the technology/the existing lump coal technology is 9.72/6.9-1.409;

the oil yield was 140.9% of the oil yield of slow pyrolysis of lump coal.

The heat value of the pyrolysis gas/the prior lump coal technology is 3992/1678-2.379;

the calorific value of the pyrolysis gas is 237.9 percent of that of the pyrolysis gas generated by slow pyrolysis of the lump coal.

The solid content of the technology/the solid content of the prior lump coal technology is 0.04/0.5-0.08;

the solid content in the coal tar is 8 percent of the basic requirement of the lump coal in the prior art.

The solid content/industry standard requirement of the technology is 0.04/3.5-7 which is 1.14-0.57%;

the technical index obviously exceeds the existing industrial standard and actual index, and has obvious advantages.

Example 2

Qualified powdered coal raw materials are processed through a raw material processing system (30), the raw materials with the particle size within the range of 0-5 mm are preferably selected, the raw materials are sent into a powdered coal bin (1), are sent into a mixer (11) through a feeding tank cache (2) and a feeder (3B), and are mixed with a hot coke storage bin (6) controlled by a heat carrier regulating valve (8) to obtain a heat carrier with the temperature of 750 +/-20 ℃, and the ratio of the raw materials to the hot coke is 1 on the upper part of the mixer (11): (3-4.2) entering and mixing, wherein the mixing temperature is about 550 +/-10 ℃, the mixture enters a riser pyrolysis reactor (12) for pyrolysis, a large amount of pyrolysis oil gas is generated, the oil gas is gas composed of gaseous tar, carbon monoxide, hydrogen, methane, carbon dioxide, hydrogen sulfide, ammonia and the like, and the riser residence time is about 3-5 seconds. Gas, a heat carrier, semicoke and the like are sprayed from an outlet of a lifting pipe (12) and enter a pyrolysis coking reactor (13), the temperature of the reactor (13) is 530 +/-10 ℃, the outer walls of a dense-phase section and a dilute-phase section of the reactor (13) are provided with three layers, 8 atomizing nozzles (15) are uniformly distributed on each layer around the outer wall, tower bottom oil containing coke dust from the bottom of a washing tower (18) is sprayed into the reactor (13) by using steam as an atomizing medium, atomized oil drops containing the coke dust are combined with high-temperature fluidized semicoke to form an oil film on the surface of the high-temperature semicoke, condensation and coking are carried out under the temperature condition of 530 +/-10 ℃ and the pressure of 0.12MPa, and the diameter of fine coke dust particles is increased; and an oil gas cyclone separator (16) at the upper part is used for carrying out gas-solid separation, oil gas containing 5.2% of coke dust enters a large oil gas pipe (17) from the top of the reactor (13), quenching oil is sprayed into the inlet of the large oil gas pipe (17), the temperature of the oil gas is reduced to 390 +/-5 ℃, the coking reaction is stopped, a vertical pipe of the large oil gas pipe is sprayed into tower bottom oil containing 3.4% of coke dust in a washing tower through a dynamic wave washing pump (22) and is in countercurrent contact with the oil gas to form foam washing, fine coke dust in the oil gas is washed off, the oil dust and condensed liquid oil enter the bottom of the washing tower (18), uncondensed oil gas continues to be washed upwards in the washing tower (18), and finally the coke dust in the oil gas is completely washed off. The oil gas is discharged from the top of the washing tower (18) to an oil gas recovery system (40) to produce products such as coking wax oil, coking diesel oil, coking gasoline, dry gas and the like.

After the semicoke at 530 +/-10 ℃ passes through a fluidized crushing and coke quenching section (14), the semicoke passes through a semicoke circulating pipe and is controlled to contact and combust with room-temperature air entering from the bottom of an inlet at the lower part of the tubular coke burner (5) by a semicoke control slide valve, and the combustion temperature is controlled to be 750 +/-20 ℃. 750 ℃ hot coke enters a hot coke storage bin (6) from an outlet at the upper part of a tubular coke burner (5), the hot coke is settled down to the storage bin (6) under the action of gravity, 750 ℃ flue gas enters a flue gas coarse cyclone (7) from the upper part of the storage bin, the flue gas after the flue gas coarse cyclone (7) is separated from dust is sent to a flue gas waste heat recovery system (60), the waste heat is recovered, after air is preheated, low-temperature flue gas is used as a heat source for drying raw materials, and finally, the atmosphere is discharged after the final treatment reaches the emission standard.

The flue gas coarse cyclone separation (7) is performed with the dipleg of 750 ℃, fine coke powder with the particle size of 30-100 mu m returns to the hot coke storage bin (6), the fine coke powder is partially stored in a fine powder collecting tank (20), the fine coke powder is blown to the inlet of an oil gas cyclone separator (16) in a pyrolysis coking reactor (13) through saturated steam with the pressure of 1.0MPa, fine powder particles are separated through the oil gas cyclone separator (16) and return to the reactor, and coked substances on the inner wall of the cyclone separator are cleaned.

The god coal feedstock used in example 2 of the present invention was subjected to griffith pyrolysis analysis. Referring to table 4, table 4 is griffith pyrolysis analysis data for the shenmuke coal feedstock used in example 2 of the present invention.

TABLE 4

And analyzing and detecting the product obtained by the coal tar preparation process by pulverized coal pyrolysis provided by the embodiment 2 of the invention. Referring to tables 5 and 6, tables 5 and 6 show the product yield and data analysis obtained in example 2 of the present invention. Wherein, table 5 is a gas quality comparison table, and table 6 is an oil yield and yield comparison table for each ton of coal.

TABLE 5

TABLE 6 comparison of products

The comparative analysis shows that when the method treats typical Shenmu powdered coal and the Shenmu coal raw material Gejin analysis shows that the yield of tar is 11.6%, the total yield of the coal tar (coking gasoline and coking diesel oil) is the quality of the raw material9.395%, the dust content in oil is 0.054%, and the heat value of pyrolysis gas is 3337KCal/Nm³. Compared with the prior art of slow pyrolysis of lump coal.

Referring to the technical requirements of coal tar of the industrial standard YB/T5075-2010, the toluene insoluble substance of the No. 1 product in the table 4 is 3.5-7%, the toluene insoluble substance is the mechanical impurity in the coal tar, and the main component is the coke dust.

The oil yield of the technology/the existing lump coal technology is 9.395/6.3-1.491;

the oil yield was 149.1% of the oil yield of slow pyrolysis of lump coal.

The heat value of the pyrolysis gas/the prior lump coal technology is 3337/1748-1.909;

the calorific value of the pyrolysis gas is 190.9% of the calorific value of the pyrolysis gas generated by slow pyrolysis of the lump coal.

The solid content of the technology/the solid content of the prior lump coal technology is 0.054/0.5-0.108;

the solid content in the coal tar is 10.8 percent of the basic requirement of the lump coal in the prior art.

The solid content/industry standard requirement of the technology is 0.054/3.5-7 which is 1.54% -0.771%;

Example 3

Qualified powdered coal raw materials are processed through a raw material processing system (30), the raw materials with the particle size within the range of 0-8 mm are preferably selected, the raw materials are sent into a powdered coal bin (1), are sent to a mixer (11) through a feeding tank cache (2) and a feeder (3B), and are mixed with a hot coke storage bin (6) controlled by a heat carrier regulating valve (8) to obtain a heat carrier with the temperature of 800 +/-20 ℃, and the raw materials and the hot coke are mixed into a mixture in a ratio of 1: (1.8-3.5) and mixing, wherein the mixing temperature is about 550 +/-10 ℃, the mixture enters a riser pyrolysis reactor (12) for pyrolysis, a large amount of pyrolysis oil gas is generated, the oil gas is gas composed of gaseous tar, carbon monoxide, hydrogen, methane, carbon dioxide, hydrogen sulfide, ammonia and the like, and the residence time of the riser is about 3-5 seconds. Gas, a heat carrier, semicoke and the like are sprayed from an outlet of a lifting pipe (12) and enter a pyrolysis coking reactor (13), the temperature of the reactor (13) is 530 +/-10 ℃, the outer walls of a dense-phase section and a dilute-phase section of the reactor (13) are provided with three layers, 5 atomizing nozzles (15) are uniformly distributed on each layer around the outer wall, tower bottom oil containing coke dust from the bottom of a washing tower (18) is sprayed into the reactor (13) by using steam as an atomizing medium, atomized oil drops containing the coke dust are combined with high-temperature fluidized semicoke to form an oil film on the surface of the high-temperature semicoke, condensation and coking are carried out under the temperature condition of 530 +/-10 ℃ and the pressure of 0.1MPa, and the diameter of fine coke dust particles is increased; and an oil gas cyclone separator (16) at the upper part is used for carrying out gas-solid separation, oil gas containing 3.9% of coke dust enters a large oil gas pipe (17) from the top of the reactor (13), quenching oil is sprayed into the inlet of the large oil gas pipe (17), the temperature of the oil gas is reduced to 390 +/-5 ℃, the coking reaction is stopped, a vertical pipe of the large oil gas pipe is sprayed into tower bottom oil containing 3% of coke dust in a washing tower through a dynamic wave washing pump (22), the tower bottom oil is in countercurrent contact with the oil gas to form foam washing, fine coke dust in the oil gas is washed off, the oil dust and condensed liquid oil enter the bottom of the washing tower (18), uncondensed oil gas is continuously washed upwards in the washing tower (18), and finally the coke dust in the oil gas is completely washed off. The oil gas is discharged from the top of the washing tower (18) to an oil gas recovery system (40) to produce products such as coking wax oil, coking diesel oil, coking gasoline, dry gas and the like.

After the semicoke at 530 +/-10 ℃ passes through a fluidized crushing and coke quenching section (14), the semicoke passes through a semicoke circulating pipe and is controlled to contact and combust with room-temperature air entering from the bottom of an inlet at the lower part of the tubular coke burner (5) by a semicoke control slide valve, and the combustion temperature is controlled to be 800 +/-20 ℃. The hot coke with the temperature of 800 ℃ enters a hot coke storage bin (6) from an outlet at the upper part of a tubular coke burner (5), the hot coke is descended to the storage bin (6) under the action of gravity, the flue gas with the temperature of 800 ℃ enters a flue gas coarse cyclone (7) from the upper part of the storage bin, the flue gas after being separated from dust through the flue gas coarse cyclone (7) is sent to a flue gas waste heat recovery system (60), the flue gas with the temperature of low temperature is used as a heat source for drying raw materials after recovering waste heat and preheating air, and finally the flue gas is treated to reach the emission standard and then is.

The flue gas coarse cyclone separation (7) is performed with the dipleg of 800 ℃, fine coke powder with the particle size of 30-100 mu m returns to the hot coke storage bin (6), the fine coke powder is partially stored in a fine powder collecting tank (20), the fine coke powder is blown to the inlet of an oil gas cyclone separator (16) in a pyrolysis coking reactor (13) through saturated steam with the pressure of 1.0MPa, fine powder particles are separated through the oil gas cyclone separator (16) and return to the reactor, and coked substances on the inner wall of the cyclone separator are cleaned.

The Goldwood coal feedstock used in example 3 of the present invention was subjected to a Gegen pyrolysis analysis. Referring to table 7, table 7 is griffith pyrolysis analysis data for the shenmuke coal feedstock used in example 3 of the present invention.

TABLE 7

And analyzing and detecting the product obtained by the coal tar preparation process by pulverized coal pyrolysis provided by the embodiment 3 of the invention. See tables 8 and 9, tables 8 and 9 for product yields and data analysis obtained in example 3 of the present invention. Wherein, table 8 is a gas quality comparison table, and table 9 is an oil yield and yield comparison table for each ton of coal.

TABLE 8

TABLE 9 comparison table of products

The comparative analysis shows that when the method is used for treating typical Shenmu powdered coal and the yield of the tar is 12.5 percent in the Shenmu raw material Gejin analysis, the total yield (coking gasoline and coking diesel oil) of the coal tar is 10.236 percent of the raw material by mass and the dust content in the oil product is 0.03 percentThe calorific value of the pyrolysis gas is 3264KCal/Nm³. Compared with the prior art of slow pyrolysis of lump coal.

Referring to the technical requirements of coal tar of the industrial standard YB/T5075-2010, the toluene insoluble substance of the No. 1 product in the table 7 is 3.5-7%, namely the toluene insoluble substance is a mechanical impurity in the coal tar, and the main component is coke dust.

The oil yield of the technology/the existing lump coal technology is 10.236/6.96 is 1.47;

the oil yield is 147% of the oil yield of slow pyrolysis of lump coal.

The heat value of the pyrolysis gas/the prior lump coal technology is 3264/1743-1.873;

the calorific value of the pyrolysis gas is 187.3% of the calorific value of the pyrolysis gas generated by slow pyrolysis of the lump coal.

The solid content of the technology/the solid content of the prior lump coal technology is 0.03/0.5-0.06;

the solid content in the coal tar is 6 percent of the basic requirement of the prior art of lump coal.

The solid content/industry standard requirement of the technology is 0.03/3.5-7, namely 0.857% -0.428%;

The above detailed description of the integrated pyrolysis-coking process and system for preparing coal tar by pyrolyzing pulverized coal according to the present invention has been provided, and the principles and embodiments of the present invention are described herein using specific examples, which are provided only to help understand the method of the present invention and its core ideas, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any device or system, and implementing any method in combination. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A process for preparing coal tar by pyrolyzing pulverized coal is characterized by comprising the following steps:

2. The process according to claim 1, wherein the pulverized coal has a particle size of 8mm or less;

the temperature of the hot semicoke is 650-1000 ℃;

the mass ratio of the pulverized coal to the hot semicoke is 1: (2-16);

the temperature of the pyrolysis reaction is 480-650 ℃;

the pyrolysis reaction time is 1-5 seconds;

the pressure of the pyrolysis reaction is 10 KPa-3 MPa;

the oil gas comprises high-dust-content gas coal tar;

3. The process of claim 1, wherein the pyrolytic coking comprises pyrolysis of coal, pyrolysis of oil shale, and coking of oil products;

the time of pyrolysis coking is 1-5 minutes;

the temperature of the pyrolysis coking is 480-650 ℃;

the pressure of the pyrolysis coking is 10 KPa-3 MPa;

4. The process of claim 1, wherein the oil-containing semicoke formed in the pyrolytic coking process is fluidized and crushed and then combusted in an oxygen-containing atmosphere to obtain hot semicoke;

the particle size of the fluidized crushing is less than or equal to 8 mm;

the combustion temperature is 650-1000 ℃;

pulverized coal is also added in the combustion process;

fine coke powder is also added in the gas-solid separation process;

5. The process according to claim 1, wherein the dust-oil ratio in the oil gas containing the micro dust is (0.5-10): 100, respectively;

the temperature for terminating the coking reaction is 380-450 ℃;

the coal tar in the step 3) is medium coal tar obtained in the washing process;

the dust content of the medium coal tar is less than or equal to 0.5 percent;

the mixing in step 3) further comprises steam;

a foam washing step is also included after the step 3);

the dust-oil ratio of the gaseous coal tar is less than or equal to 0.08%.

6. A system for preparing coal tar by pyrolyzing pulverized coal is characterized by comprising a riser pyrolysis reactor;

a cyclone separator is arranged at the top of the pyrolysis coking reactor;

a cooling scrubber connected to the outlet of the cyclone;

7. The system of claim 6, wherein the riser pyrolysis reactor comprises one or more of a single-riser pyrolysis reactor, a dual-riser pyrolysis reactor, and a multi-riser pyrolysis reactor;

the system further comprises a pulverized coal feed system and/or a mixer;

8. The system of claim 6, wherein a plurality of spray devices are disposed within the pyrolytic coking reactor;

the spraying device is connected with the bottom of the cooling washing tower;

9. The system of claim 8, wherein the solid char combustion device comprises one or more of a tubular fluidized bed char burner, a fluidized bed gasifier, and a fluidized bed boiler;

10. The system of claim 8, wherein the solid phase outlet end of the fluidized crushed coke quenching section is further connected to a char application storage system;