CN215712800U

CN215712800U - Device for continuously extracting oil gas from medium and low-rank coal

Info

Publication number: CN215712800U
Application number: CN202121174551.1U
Authority: CN
Inventors: 程相魁
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-02-01
Anticipated expiration: 2031-05-28

Abstract

The utility model belongs to the technical field of coal chemical industry, and particularly relates to a device for continuously extracting oil gas from medium and low-rank coal. The device comprises a storage bin, a sealed coal charging device, a prestoring section, a drying preheating section, a multi-stage gradient temperature-rising pyrolysis section, a coke stewing section, a single-hole combined-path dry quenching section, a coke poking device and a sealed coke discharging machine which are sequentially connected from top to bottom; the multi-stage gradient heating pyrolysis section comprises more than three continuous stages, and each stage is respectively connected with a coal gas outlet; the device also comprises a heating section for indirectly supplying heat to the multi-stage gradient heating pyrolysis section. The device thoroughly solves the problems of polluted gas emission and high noise pollution from the source; the method has the advantages that the precious hydrocarbon compounds in the coal gas are prevented from secondary cracking by segmented pyrolysis and segmented extraction according to different temperatures; the dry quenching recovers about 90 percent of sensible heat of the coke, and reduces about 80 percent of energy consumption compared with the conventional dry quenching process.

Description

Device for continuously extracting oil gas from medium and low-rank coal

Technical Field

The utility model belongs to the technical field of coal chemical industry, and particularly relates to a device for continuously extracting oil gas from medium and low-rank coal.

Background

Generally, volatile matters of low-rank coal (brown coal, long flame coal, non-sticky coal and weakly sticky coal) and medium-rank coal with volatile components of more than 18 percent are mainly volatile mattersIs composed of hydrocarbon substances. In the volatile matter of the medium and low rank coal with the volatile matter of more than 25 percent, the hydrocarbon component generally accounts for more than 75 percent of the weight ratio of the anhydrous base volatile matter. In particular, in low-rank coal having a low degree of coalification, the hydrocarbon component generally accounts for 25% or more of the total mass ratio of the coal. If the hydrocarbon substance is pyrolyzed (i.e. secondary cracking) with approximate initial components under proper process conditions, about 40% of the hydrocarbon substance is C after separation and purification_1～4A gaseous substance mainly containing alkane and olefin, wherein the gaseous substance can be used for extracting clean vehicle fuel LNG (liquid methane) and civil liquefied gas (the main component is liquid propane) with high added value through further cryogenic separation; about 5 percent of liquid light hydrocarbon products; the rest 50% is light tar for preparing high-quality vehicle oil.

However, a great amount of medium/low-rank medium and high-volatile coal rich in high value-added hydrocarbon components is directly combusted to be used for power generation, industrial heating or other civil fuels every year, so that not only is precious resources greatly wasted, but also the environmental protection cost and the production cost are greatly increased.

Secondly, a considerable part of the low-rank coal is used for producing semi coke. However, due to the defects of the process and the device adopted by the enterprises, at least about 70 percent of valuable hydrocarbon compounds in the raw material coal are cracked and destroyed, and the pollution source is increased.

In addition, a small part of the catalyst is used for gas making and the production of methanol, dimethyl ether, synthetic ammonia and the like. However, since such enterprises almost adopt an indirect conversion production process of fully cracking raw material coal and hydrocarbon components therein and then synthesizing the raw material coal and the hydrocarbon components therein, valuable hydrocarbon components are destroyed, investment, energy consumption, pollution links and production cost are high, and living space of the enterprises is greatly limited.

In the conventional coking (high-temperature dry distillation) process, although a small amount of coal chemical products are extracted, the added value of the products is greatly reduced. This is because the main product of the conventional dry distillation process is metallurgical coke, which must be produced at high temperature to produce a product of acceptable qualityThe volatile components of coal are subjected to not only low-temperature primary pyrolysis but also high-temperature secondary pyrolysis, resulting in the cracking of most of the valuable hydrocarbon materials into H₂And free C, which can deteriorate the quality of coal gas and greatly increase the asphaltene in tar.

Compared with the high-temperature dry distillation technology, the adoption of the medium-low temperature segmented pyrolysis technology is more beneficial to improving the light hydrocarbon content of the coal gas, so that precious light hydrocarbon products can be directly extracted and utilized, and the coal gas after oil gas extraction is suitable for being used as synthesis gas, thereby creating conditions for producing alcohol ether fuel or hydrocarbon substances such as synthetic alkane and alkene and the like and improving the utilization value of the coal gas; the yield of tar is improved, the tar components are further improved, and the utilization value of the tar is improved; the method is favorable for recycling light hydrocarbon and phenol, improves the efficiency of converting light hydrocarbon and phenol into high-quality energy, greatly reduces the energy consumption and the product cost in the conversion process, and can greatly improve the added value of products.

The key to realizing medium and low temperature pyrolysis is the process and the furnace type. Although a plurality of middle-temperature and low-temperature dry distillation processes and furnace types can play a little role in middle-temperature and low-temperature pyrolysis at present, most of the furnace types adopt an internal heating type process taking air-rich waste gas as a gas source, so that not only the effective components of coal gas are diluted by a large amount of nitrogen, but also more than 70 percent of valuable alkane compounds are seriously damaged! Although most people are accustomed to refer to this type of oven as a retort oven, it is not strictly notional of dry distillation as "heating with air exclusion". The key point is that the furnaces produce the semicoke by taking dry distillation as a main purpose, and the precious hydrocarbon chemical products pyrolyzed are not positioned as a main process target, so that the hydrocarbon compounds cannot be pyrolyzed effectively in an ideal state, and the great damage and waste of high-quality resources are caused.

At present, the industry has realized that the best utilization approach of low-rank coal is to perform medium-low temperature pyrolysis, extract valuable hydrocarbon components in volatile components, generate power by using residual carbon or generate synthesis gas by gasification, and further indirectly convert the synthesis gas or synthesis oil. And a large amount of work is done in the aspect of low-rank coal pyrolysis, but the process and equipment of the method are mainly rotary furnace, moving bed, fluidized bed, entrained flow bed or solid heat carrier pyrolysis technologies, and the method mainly belongs to the dynamic pyrolysis process idea of relative rapid movement of solid powdery materials by integrating the characteristics of the pyrolysis technologies. Therefore, the common problems of the processes are that the yield of oil gas is low, the content of asphaltene in pyrolysis oil is high, tar and system dust are difficult to separate, and the like, so that large-scale industrial application is not available at present. And is generally considered by those skilled in the art to be: the key technology for breaking through pyrolysis is product separation, lightening of pyrolysis oil and scale enlargement.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a device for continuously extracting oil gas from medium and low-rank coal by adopting an indirect heating and sectional pyrolysis mode. The device provided by the utility model heats the material in a relatively static state, adopts multi-stage gradient temperature rise which is easy to control, indirectly heats and pyrolyzes in sections, automatically separates gas and solid states in the process, and overcomes the process defects caused by dynamic gas and powdery solid two-phase flow in a heating system.

Specifically, the utility model provides the following technical scheme:

an indirect heating and sectional pyrolysis device for continuously extracting oil gas from medium/low-rank coal comprises a storage bin, a sealed coal charging device, a prestoring section, a drying and preheating section, a multi-stage gradient heating pyrolysis section, a coke stewing section, a single-hole joint-pass dry quenching section, a coke pushing device and a sealed coke discharging machine which are sequentially connected from top to bottom; the multi-stage gradient heating pyrolysis section comprises more than three continuous stages, and each stage is respectively connected with a coal gas outlet; the device also comprises a heating section for indirectly supplying heat to the multi-stage gradient heating pyrolysis section.

Preferably, the heating section is directly adjacent to the multi-stage gradient heating pyrolysis section, and comprises one heating stage corresponding to each pyrolysis stage.

The bottom of the heating section is provided with an air inlet and a combustible gas inlet which are respectively connected with an air passage and a return gas pipeline; the heating section is also provided with a waste gas outlet which is connected with a waste gas channel positioned below the heating section.

The single-hole linked-process dry quenching section can comprise a connected single-hole linked-process high-temperature dry quenching section and a single-hole linked-process medium-low-temperature dry quenching heat exchanger from top to bottom. The air channel is positioned between the single-hole linked high-temperature dry quenching section and the waste gas channel and is respectively and directly adjacent to the single-hole linked high-temperature dry quenching section and the waste gas channel.

In the device, combustion-supporting air indirectly absorbs the heat of the waste gas on one side and the sensible heat of red hot coke on the other side in an air channel, and enters the bottom of the high-temperature heating section after being preheated to be mixed with coal gas for combustion; the waste gas indirectly transfers part of heat to air and then is discharged out of the furnace; the red hot coke indirectly transfers part of heat to air, and meanwhile, the downward speed of the briquette coke is less than 0.5mm/s, preferably less than 0.3mm/s, so that power and dust cannot be consumed in the heat exchange process. The red hot coke enters a single-hole linked low-temperature dry quenching section after being cooled in the single-hole linked high-temperature dry quenching section, and is cooled to below 120 ℃ under the combined action of indirect cooling of softened cold water in a heat exchanger shell and direct cooling of water vapor generated by a water atomizer.

Preferably, the coke poking device is provided with a cooling medium inlet. The cooling medium entering the cooling medium inlet can be a liquid phase, and the liquid phase is changed into a gas phase by absorbing the sensible heat of the coke, then sequentially passes through a single-hole linked-path dry quenching section, a coke stewing section and a multi-stage gradient heating pyrolysis section and is led out from a gas outlet, so that the coke is cooled and the heat is recovered; the cooling medium entering the cooling medium inlet can also be cold gas such as cold coal gas, and after absorbing the sensible heat of the coke, the cold coal gas passes through a single-hole linked-path dry quenching section, a coke stewing section and a multi-stage gradient temperature-rising pyrolysis section in sequence, and high-temperature coal gas is led out from a coal gas outlet, so that the coke is cooled, and the heat is recovered.

Preferably, a water atomizer can be arranged in the coke poking device. The water vapor generated by the water atomizer after being atomized and absorbing the sensible heat of the coke passes through a single-hole joint-pass dry quenching section, a coke stewing section and a multi-stage gradient heating pyrolysis section in sequence, and the generated water gas is led out from a gas outlet as a product. In the rising process, the water vapor plays a medium role of convection heat transfer of large temperature difference between the central coke and the outer coke, so that the indirect heat exchange with air and the indirect heat exchange with cooling water are faster and more efficient.

The number of stages of the multi-stage gradient heating pyrolysis section can be adjusted according to actual needs, for example, the multi-stage gradient heating pyrolysis section can be composed of three stages, namely a low-temperature pyrolysis section, a medium-temperature pyrolysis section and a high-temperature pyrolysis section in sequence. In this case, the device comprises a storage bin, a sealed coal charging device, a pre-storage section, a drying preheating section, a low-temperature pyrolysis section, a medium-temperature pyrolysis section, a high-temperature pyrolysis section, a coke stewing section, a single-hole joint-process high-temperature dry quenching section, a single-hole joint-process medium-low-temperature dry quenching heat exchanger, a coke poking device and a sealed coke discharger which are sequentially connected from top to bottom; each pyrolysis section is respectively connected with a coal gas outlet.

In order to optimize the effect, the device is preferably fully sealed, and the downward speed of the material is controlled by a coke poking device.

The device provided by the utility model not only can realize cold-state coal charging and cold-state coke discharging so as to prevent a large amount of dust generated by hot buoyancy, but also adopts the sealed coal charging device and the sealed coke discharging device to strictly control unorganized discharge, really realizes efficient fully-closed production in the whole process, controls pollution of pollutants to the atmosphere from the source and reduces the environmental protection cost. The pyrolysis section consists of pyrolysis temperature sections with gradient temperature rise from top to bottom, meanwhile, different stages of the heating section from bottom to top respectively supply heat for the pyrolysis chamber, and raw gas with different components thermally decomposed in different temperature sections is led out from corresponding gas leading-out ports respectively, so that high-quality oil and gas components thermally decomposed in relatively low temperature areas are prevented from being secondarily cracked at high temperature or secondary high temperature.

In the device, after coal gas generated in pyrolysis zones with different temperatures is led out from a plurality of coal gas leading-out holes, low-temperature hydrocarbon-rich coal gas mainly containing hydrocarbon compounds is mixed with medium-temperature medium hydrocarbon coal gas, and then the mixture is purified and separated to extract C with high added value₁～₄The gas obtained after extracting the chemical products directly converted from the gaseous alkane, the light hydrocarbon oil, the light tar and a small amount of medium/heavy tar can be used for extracting hydrogen or CO and H thereof according to the needs₂Indirectly converted into hydrocarbon products or alcohol ether products, and the restThe steam can be produced by heating in a furnace, and the like.

The solid substance with carbon as main component after pyrolysis can be used for producing synthesis gas CO and H by adopting corresponding process after pyrolysis according to requirements₂Further indirectly converting into chemical products required by the market; or the material can be used for manufacturing blast furnace injection material, smokeless fuel or gasified coke, and can also be used for producing casting formed coke or metallurgical formed coke so as to improve the resource utilization rate.

The utility model also provides a process for continuously extracting oil gas from medium/low-rank coal by adopting an indirect heating and staged pyrolysis mode, which comprises the following steps:

(1) pressing and molding the medium/low-rank coal to obtain medium/low-rank molded coal, and inputting the medium/low-rank molded coal into a drying and preheating section for preheating treatment;

(2) inputting the medium/low-rank briquette subjected to preheating treatment into a pyrolysis section, performing gradient temperature rise pyrolysis for more than three stages in an indirect heating mode, and continuously collecting hydrocarbon gas generated in each stage;

(3) feeding the solid product obtained after pyrolysis into a coke sealing section for carrying out coke stewing treatment;

(4) inputting coke obtained by braising into a coke quenching section for coke quenching treatment, inputting into a coke removing section for coke removing treatment, and discharging the obtained low-temperature coke through a sealed coke removing section;

wherein, the transportation of the medium/low-rank briquette in the whole process is realized by descending at a speed of less than 0.5mm/s by gravity in a sealed state.

The medium/low rank coals according to the present invention are conventional medium rank coals and low rank coals known in the art, and the present invention is not particularly limited to the parameters thereof. The medium/low-rank coal can be cold powdery coal, and molded coal can be obtained after pressing and can be used for treatment in subsequent steps.

The indirect heating of the utility model specifically means: the medium/low-rank briquette carries out heat exchange and temperature rise through the heat transferred by the partition wall under the condition of not directly contacting with a heat source.

In the coke removing step, water vapor can be introduced, and the water vapor is sequentially subjected to direct heat exchange with the coke in the coke removing, single-hole combined-path dry quenching, coke stewing and pyrolysis steps in the rising process to assist in efficient coke quenching and generate water gas; and leading out the water gas.

The coke quenching section comprises a high-temperature dry quenching section and a medium-low temperature dry quenching section; in the high-temperature dry quenching stage, the high-temperature coke and low-temperature air perform indirect heat exchange, and simultaneously perform direct heat exchange with water vapor, so that the waste heat recovery of the high-temperature coke is realized; in the medium and low temperature dry quenching stage, the medium and low temperature coke and cooling water are subjected to indirect heat exchange, and simultaneously the medium and low temperature coke and water vapor are subjected to direct heat exchange, so that the waste heat recovery of the medium and low temperature coke is realized.

The stage of the gradient temperature-rising pyrolysis can be determined according to the actual production requirement. Taking three stages of gradient temperature rise pyrolysis as an example, the three stages are sequentially: carrying out low-temperature pyrolysis at 380-450 ℃, then carrying out medium-temperature pyrolysis at 500-600 ℃, and then carrying out high-temperature pyrolysis at 850 ℃.

As a preferred scheme, the process comprises the following steps:

(1) pressing cold powdery medium/low-rank coal into formed coal, and inputting the formed coal into a drying and preheating section for preheating treatment;

(2) inputting the medium/low-order molded coal subjected to preheating treatment into a pyrolysis section, performing low-temperature pyrolysis at 380-450 ℃ by adopting an indirect heating mode, performing medium-temperature pyrolysis at 500-600 ℃, performing high-temperature pyrolysis at more than 850 ℃, and continuously collecting gases containing different hydrocarbon components generated in each stage respectively;

(4) inputting coke obtained by braising into a coke quenching section, carrying out indirect heat exchange on high-temperature coke and air in a high-temperature dry coke quenching section, simultaneously carrying out direct heat exchange with water vapor, quenching the coke to 350-450 ℃, then entering a medium-low temperature dry coke quenching section, carrying out indirect heat exchange with cooling water, simultaneously carrying out direct heat exchange with the water vapor, reducing the temperature of the coke to below 120 ℃, inputting the coke into a coke removing section for coke removing treatment, and discharging the obtained low-temperature coke through a sealed coke removing section;

meanwhile, collecting the water gas generated by the reaction of the water vapor and the high-temperature coke as a product;

The key technology of the process provided by the utility model is that the step temperature heating of the coal as fired is realized, three or more temperature sections are correspondingly arranged according to different requirements on the components of the coal gas to lead out the raw coke oven gas containing different hydrocarbon components, and the fully-closed continuous production process of cold-state charging and cold-state discharging is realized, so that the yield of high-quality light tar is improved in the pyrolysis process of the coal material, the proportion of alkane in the raw coke oven gas is greatly improved, and the multi-component coal gas capable of preparing high-quality oil and gas is produced according to the requirements; simultaneously, the method can produce blast furnace injection materials, smokeless fuels or gasification coke and can also produce casting formed coke or metallurgical formed coke, thereby improving the resource utilization rate; in order to realize high efficiency of heat energy utilization, the sensible heat of the clean solid semi-coke and the raw coke gas can be recycled.

The utility model has the following beneficial effects:

(1) the design of the conventional horizontal chamber type intermittent production dry distillation coking device is original, mainly aims at producing metallurgical coke or foundry coke, and the recovery of coal gas and chemical products is a derivative process, so qualified coke can be produced only by uniformly heating and dry distilling under the high temperature condition, and the heating temperature of a coking chamber is required to be consistent; the conventional dry distillation device cannot be provided with a coal gas outlet in a stepped temperature subsection manner, and only can perform dry distillation under a single temperature condition, so that most of high-quality hydrocarbon compounds in coal gas are cracked secondarily at high temperature or secondary high temperature, and the content of precious high-quality hydrocarbon compounds in raw coal gas is greatly reduced; if medium and low temperature dry distillation is adopted, the volatile components in the coal material can not be fully released, so that the quality of the coke can not meet the requirements of qualified metallurgical coke and casting coke, and the process limits the high-efficiency recovery of chemical products;

compared with the prior art, the process and the device for continuously extracting the oil gas by indirectly heating and sectionally pyrolyzing the low-rank coal, which are developed by the utility model, have the greatest production purpose of extracting the hydrocarbon compounds and have the subordinate purpose of producing the semicoke or the metallurgical coke; the device can be provided with two, three or more coal gas outlet ports with different temperature sections according to the requirements of users on products and different pyrolysis temperature areas; generally, three gas outlet ports of low temperature, medium temperature and high temperature are arranged to obtain gas with different components generated under different temperature conditions, namely, the pyrolysis chamber adopts different temperature sectional heating and sectional outlet, hydrocarbon compounds with low pyrolysis temperature in coal volatile are led out while being distilled out in the low temperature pyrolysis section, and hydrocarbon compounds with higher pyrolysis temperature are led out while being distilled out in the medium temperature pyrolysis section, and so on; the hydrocarbon compounds contained in the raw gas are effectively controlled not to be subjected to secondary cracking in a higher primary temperature area through segmented derivation, so that precious high-quality hydrocarbon compounds are not damaged; after the coal material enters the high-temperature pyrolysis section, continuously and fully distilling off the residual volatile components and leading out the residual volatile components from a high-temperature coal gas outlet to produce the lean hydrocarbon hydrogen-rich coal gas and the high-temperature coke or the coke meeting other requirements. Therefore, alkane components are not damaged to the maximum extent, and coal gas in different temperature sections can be combined or respectively purified and separated according to downstream product requirements, so that the energy consumption and the processing cost of the product can be reduced by about 50 percent compared with the indirect conversion process, and chemical products with higher quality than the indirect conversion can be recovered.

(2) The conventional external heating vertical retort mostly adopts an up-down alternate (reversing) heating mode, so the temperature of the combustion chamber is basically consistent, the temperature of the upper part of the wall of the carbonization chamber is overhigh, and the oil and gas which are pyrolyzed by primary heat are cracked again by high temperature for the second time in the rising process, so most of valuable hydrocarbon compounds are damaged;

compared with the prior art, the utility model has the key that the step temperature heating of the coal as fired is realized, the oil and the gas which are pyrolyzed in the low-temperature section and the middle-temperature section are respectively and directly led out from the low-temperature coal gas outlet and the middle-temperature coal gas outlet by adopting the sectional indirect heating, so that the oil and the gas are not influenced by the secondary pyrolysis in a higher-level temperature area, the problem that the oil and the gas are subjected to the secondary pyrolysis is well solved, and the precious high-quality hydrocarbon compounds are not damaged.

(3) At present, the so-called vertical medium-low temperature dry distillation devices popular in China mostly adopt an internal heating mode that oxygen-containing waste gas is used as a gas source; when the process uses oxygen-containing waste gas as a gas source to heat the gas in a carbonization chamber, not only at least more than 70 percent of hydrocarbon substances in the gas are damaged, but also a large amount of nitrogen brought into the air dilutes the concentration of effective components, so that hydrocarbon compounds in the gas cannot be extracted in positive benefit (extraction must be negative benefit when the hydrocarbon content is particularly low), but also the heat value of the gas is greatly reduced;

compared with the prior art, the developed sectional indirect heating method adopts an external heating mode of completely isolating the combustion chamber from the pyrolysis chamber, ensures that precious hydrocarbon compounds are not damaged by oxygen in the air and are not diluted by nitrogen, improves the recovery rate of quality products and the resource utilization rate, and ensures that the calorific value of coal gas is at least three times of that of an air source internal heating type gas retort.

(4) At present, a great deal of work is done in the aspect of low-rank coal pyrolysis in many countries, and most of the countries carry out pilot scale test or industrial demonstration, but the processes and equipment of the low-rank coal pyrolysis technology are mainly rotary furnaces, moving beds, fluidized beds, entrained flow beds or powdery solid heat carriers, the characteristics of the pyrolysis technologies are integrated, the low-rank coal pyrolysis technology belongs to the dynamic pyrolysis technology thought of relative rapid movement of solid powdery materials, and the high-rank coal pyrolysis technology has no large-scale industrial application so far; the common problems are that the yield of oil gas is low, the content of asphaltene in pyrolysis oil is high, tar is difficult to separate from system dust, and the like;

compared with the prior art, the utility model develops the step heating temperature area which is easy to control, so that the low-rank coal is subjected to subsection indirect heating pyrolysis and the raw coke oven gas is led out in a subsection way, thereby controlling the low separation temperature compound to be free from sub-high temperature cracking; the block material is relatively statically heated at a descending speed of less than 0.5mm per second, so that the gas-solid two states are automatically separated in the process, and the common defect of the relative dynamic pyrolysis process is well overcome.

(5) In the prior art, the running or running vertical middle-low temperature gas retort takes low-strength low-rank lump coal as a raw material, and because the lump coal rate in the low-rank raw coal is generally only about 30 percent, about 70 percent of slack coal rich in hydrocarbon compounds can only be directly combusted for power generation and the like, precious resources are greatly wasted, and pollution is increased; if the slack coal is directly used for pyrolysis, the defects of difficult separation of tar and system dust and the like still exist; some people put the slack coal into the furnace instead of lump coal, but because the processing technology has defects and 6-13% of volatile matters still remain in the semicoke of the technology, the strength is greatly reduced, the briquette is mostly returned to a crushed powder, the coke discharging link is deteriorated, and the product market value is greatly reduced;

compared with the prior art, the utility model adds the high-temperature pyrolysis section and the braising section in the pyrolysis process on the basis of improving the defects of the conventional process, so that the volatile component of the coke can be reduced to below 1.5 percent, the briquette of the coke is not damaged, the briquetting rate reaches above 95 percent, the application of the coke is widened, and the benefit of an enterprise can be greatly improved.

(6) In the general pyrolysis process, the sensible heat of the red-hot semicoke of the clean solid is not recovered; the method is characterized in that the intensity of the semicoke after pyrolysis is very low, a large amount of scrap powder is generated, if a conventional dry quenching process using inert gas as a heat carrier is adopted, firstly, the semicoke is discharged in a hot state, transported in the hot state and loaded into a dry quenching furnace in the hot state, and the three links are large in the discharge of unorganized pollutants caused by thermal buoyancy, and a large amount of inert gas is required to directly exchange heat with red hot coke, so that the resistance of system medium gas is large, the gas-solid separation is difficult, the abrasion of a boiler pipe and a fan is serious, the energy consumption is high, the product burning loss rate is high, a certain amount of air is continuously sent to combust due to the separation of coal gas in the dry quenching process, the circulating medium gas is continuously increased, and the medium gas containing a certain amount of harmful substances is inevitably discharged into the atmosphere to pollute the environment. The blower of thousands of kilowatts not only has high energy consumption, but also causes the disadvantages of high noise pollution and the like;

compared with the prior art, the unique process for the single-hole combined process dry quenching completely controls the occurrence of various defects of the conventional dry quenching from the source. The novel process technology is that a part of sensible heat of red hot coke is indirectly transferred to cooling water and combustion air before the red hot coke is discharged from a furnace, and the other part of sensible heat is directly transferred to water vapor participating in water gas reaction, so that the temperature of the coke is reduced to about 100 ℃ and the coke is discharged through a sealed coke discharging device, and the coke is operated in a fully-closed and non-leakage manner under a near-static condition with the running speed of less than 0.5mm/s in the whole process; the proposal provided by the utility model completely cancels the intermediate links of thermal state coke discharging, coke transporting, coke loading and the like which inevitably generate unorganized discharge, not only completely eradicates the unorganized discharge and the harmful gas discharge generated by the thermal buoyancy, and the harmful gas is recycled efficiently, the circulation of large-flow medium gas is not needed, the gas circulation is saved, the huge power of a dust removal device is greatly reduced, the environment is not polluted by the emission of redundant harmful gas, the problem of the combustion loss of coke of about 1.5 percent of the conventional dry quenching coke is completely controlled from the source, a high-temperature circulating fan with thousands of kilowatts of large power is cancelled, the high-power consumption of coke discharging, coke loading, coke lifting and conveying devices and the circulating fan is saved, the process energy consumption is reduced by about 80 percent, and the problems of the emission of the conventional dry quenching coke polluted gas and high noise pollution are thoroughly solved from the source.

(7) The synthesis gas produced by the conventional water gas producer takes water vapor as a gas source. The water vapor device has high investment, low heat exchange efficiency, high energy consumption and poor gas quality because the water vapor device needs to intermittently feed air for heating and consumes a large amount of fuel, and has potential safety hazard.

Compared with the prior art, the water atomizer is arranged in the coke poking device at the lower part of the single-hole joint low-temperature dry quenching heat exchanger, and a proper amount of water is atomized by the atomizer and then directly exchanges heat with coke at about 100 ℃ and above to generate water vapor with high efficiency, so that a water vapor generating device with a complex structure, low heat exchange efficiency and high investment is omitted; the water vapor rises along the coke path due to the thermal buoyancy, and continuously and efficiently exchanges heat with the coke with gradually increased temperature to raise the temperature in the rising process, so that the water vapor and the red hot coke continuously descending at 950 ℃ or above are subjected to water gas reaction to produce high-quality synthesis gas after the temperature of the water vapor reaches about 950 ℃; its process investment is very low, heat efficiency is very high, it has no need of feeding air to heat, and can completely save high fuel consumption of conventional water gas producer, so that its energy consumption is low, and the gas contains N₂Low quality, no potential safety hazard, and is suitable for all kinds of peopleThe single-hole linked-process dry quenching device plays a role in strengthening and cooling the coke, so that the coke is cooled to about 100 ℃, and about 90% of sensible heat of the coke is recycled.

Drawings

FIG. 1 is a schematic view of the apparatus according to the present invention; wherein: 1. a storage bin, 2, a sealed coal charging device, 3, a prestoring section, 4, a drying preheating section, 5, a low-temperature pyrolysis section, 6, a low-temperature heating section, 7, a medium-temperature pyrolysis section, 8, a medium-temperature heating section, 9, a high-temperature pyrolysis section, 10, a high-temperature heating section, 11, a brick gas channel, 12, a coke stewing section, 13, a waste gas channel, 14, an air channel, 15, a single-hole combined process high-temperature dry quenching section, 16, an air inlet, 17, a single-hole combined process low-temperature dry quenching heat exchanger, 18, a water atomizer, 19, a coke poking device, 20, a sealed coke exhauster, 21, a low-temperature gas guide outlet, 22, a medium-temperature gas guide outlet, 23, a high-temperature gas guide outlet, 24, a gas branch pipe, 25, a return furnace gas pipeline, 26, a waste gas guide outlet, 27 and a waste gas main pipe.

Detailed Description

The following examples are intended to illustrate the utility model but are not intended to limit the scope of the utility model. The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications.

In the description of the present invention, unless otherwise specified, the terms "upper", "lower", and the like indicate orientations or state relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the following examples, the equipment and the like used are not shown to manufacturers, and are all conventional products available from regular vendors. The process is conventional unless otherwise specified, and the starting materials are commercially available from the open literature.

Example 1

A device for continuously extracting oil gas from medium/low-rank coal by adopting an indirect heating and sectional pyrolysis mode (partially referring to figure 1); the device comprises a storage bin 1, a sealed coal charging device 2, a pre-storage section 3, a drying preheating section 4, a low-temperature pyrolysis section 5, a medium-temperature pyrolysis section 7, a high-temperature pyrolysis section 9, a coke stewing section 12, a single-hole linked-process high-temperature dry quenching section 15, a single-hole linked-process medium-low-temperature dry quenching heat exchanger 17, a coke poking device 19 and a sealed coke exhauster 20 which are sequentially connected from top to bottom;

the low-temperature pyrolysis section 5 is also connected with a low-temperature coal gas outlet 21;

the medium-temperature pyrolysis section 7 is also connected with a medium-temperature coal gas outlet 22;

the high-temperature pyrolysis section 9 is also connected with a high-temperature coal gas outlet 23;

the device is a fully-closed device; the downward speed of the solid material is controlled by a coke-stripping device 19.

Example 2

Compared with the embodiment 1, the device for continuously extracting oil gas from medium/low-rank coal by adopting an indirect heating and sectional pyrolysis mode (partially refer to fig. 1) further comprises a high-temperature heating section 10, a medium-temperature heating section 8 and a low-temperature heating section 6 which are sequentially connected in sequence; the high-temperature heating section 10 is directly adjacent to the high-temperature pyrolysis section 9; the medium-temperature heating section 8 is directly adjacent to the medium-temperature pyrolysis section 7; the low-temperature heating section 6 is directly adjacent to the low-temperature pyrolysis section 5;

the low-temperature heating section 6 is provided with a waste gas outlet which is communicated with a waste gas channel 13 positioned below the high-temperature heating section 10; the exhaust gas duct 13 is connected to an exhaust gas outlet 26 and an exhaust gas manifold 27 in sequence;

the device further comprises an air channel 14; one end of the air channel 14 is an air inlet 16, and the other end is connected with an air inlet at the bottom of the high-temperature heating section 10; the air channel 14 is positioned between the waste gas channel 13 and the single-hole linked high-temperature dry quenching section 15 and is respectively and directly adjacent to the waste gas channel 13 and the single-hole linked high-temperature dry quenching section;

the device also comprises a return gas pipeline 25, a gas branch pipe 24 and a brick gas pipeline 11 which are sequentially connected, wherein the outlet of the brick gas pipeline 11 is connected with the combustible gas inlet at the bottom of the high-temperature heating section 10.

Example 3

Compared with the embodiment 2, the device for continuously extracting oil gas from medium/low-rank coal by adopting an indirect heating and staged pyrolysis mode (as shown in fig. 1) is characterized in that a cooling medium inlet is further arranged in the coke pushing device 19, the cooling medium entering the cooling medium inlet is cold coal gas, and the cold coal gas sequentially passes through the single-hole linked medium-low temperature dry quenching heat exchanger 17, the single-hole linked high-temperature dry quenching section 15, the smoldering coke section 12 and the high-temperature pyrolysis section 9, and is guided out from the coal gas guide outlet 23 after being heated.

Example 4

The method for continuously extracting oil gas by indirectly heating and sectionally pyrolyzing low-rank coal by adopting the device in the embodiment 3 specifically comprises the following steps:

the top of the pyrolysis device is provided with a bin 1 and a sealed coal charging device 2; starting the sealed coal charging device 2 during coal charging, feeding the pressed molded coal in the bin 1 into the prestoring section 3 through the sealed coal charging device 2, and sealing and isolating the airflow of the bin 1 and the prestoring section 3 by the sealed coal charging device 2 all the time in the running or stopping process; the molded coal falls into a drying and preheating section 4 from a prestoring section under the action of gravity; the dried and preheated molded coal flows downwards to enter a low-temperature pyrolysis section 5 by virtue of gravity; the molded coal releases low-temperature raw gas containing a large amount of hydrocarbon compounds in the low-temperature pyrolysis section 5 and is led out through a low-temperature gas outlet 21 so as to ensure that the gas separated from the low-temperature distillation is not subjected to secondary cracking at high temperature and secondary high temperature, and the molded coal subjected to low-temperature pyrolysis continuously flows downwards to enter the medium-temperature pyrolysis section 7; the molded coal releases medium-temperature raw gas with medium hydrocarbon compound content in the medium-temperature pyrolysis section 7 and is led out through the medium-temperature gas outlet 22, so that the gas separated from the medium-temperature fraction is prevented from being cracked at a high temperature for the second time, the molded coal gradually forms semicoke after being pyrolyzed at the medium temperature, and the molded coal continuously goes downwards to the high-temperature pyrolysis section 9; the high-temperature low-hydrocarbon raw gas mainly comprising hydrogen gas thermally decomposed in the high-temperature pyrolysis section 9 is led out through a high-temperature gas outlet 23, and the molded coal is carbonized into coke after releasing volatile matters in the high-temperature pyrolysis section and then flows downwards into the smoldering section 12; the coke is fully carbonized after further fully releasing volatile matters in the coke stewing section 12, the heat release process is carried out after the coke is fully carbonized, the coke is heated again by the released heat, and the coke continuously descends into the single-hole linked-process high-temperature dry quenching section 15; 30% sensible heat of the coke is transferred to combustion-supporting air of the air channel 14 through indirect heat exchange in a single-hole combined-process high-temperature dry quenching section, and the coke loses a part of heat and is cooled to about 400 ℃, and then the coke downwards enters a single-hole combined-process low-temperature dry quenching heat exchanger 17 through gravity; part of the sensible heat of the coke in the single-hole joint low-temperature dry quenching heat exchanger 17 is indirectly cooled by soft water (the soft water before entering a boiler) in the shell of the heat exchanger 17 and then continuously enters a coke poking device 19 in a downward way; the coke is slowly and orderly discharged by the coke poking device and falls into the sealed coke discharging machine 20, and the sealed coke discharging machine discharges the coke and falls into the conveyor to be conveyed out under the condition of effectively isolating external air and internal coke process gas;

purified coal gas sent from the return coal gas pipeline 25 is sent to the brick coal gas pipeline 11 at the bottom of the combustion chamber through the coal gas branch pipe 24, and then is distributed to enter the bottom of the high-temperature heating section 10 through the brick coal gas pipeline 11; after entering from the air inlet 16, the air is distributed to the air passages 14 which are arranged up and down at two sides, the combustion-supporting air in the air passages 14 indirectly absorbs the heat of red hot coke in the single-hole linked high-temperature dry quenching section and the heat of waste gas in the waste gas passages and is indirectly preheated to about 450 ℃, and then enters the bottom of the high-temperature heating section 10 to be mixed with coal gas from the brick gas passage 11 for combustion; the high-temperature waste gas after burning indirectly transfers partial heat to the material coke in the carbonization stage of the high-temperature pyrolysis section in the high-temperature heating section 10, and the high-temperature waste gas loses partial heat and is cooled and then enters the medium-temperature heating section 8; the waste gas indirectly transfers a part of heat to the materials in the medium-temperature pyrolysis section in the medium-temperature heating section 8, and the waste gas loses a part of heat again and enters the low-temperature heating section 6 after being cooled; the waste gas is indirectly absorbed by the materials in the low-temperature pyrolysis section in the low-temperature heating section 6, and the waste gas loses part of heat again, is cooled and enters the waste gas channel 13 through a waste gas channel in the partition wall; the waste gas indirectly transfers a part of heat to the air in the air channels 14 at the two sides in the waste gas channel 13, the waste gas is cooled again and enters the waste gas outlet 26, and then the waste gas is sent to the waste heat boiler through the waste gas main pipe 27 to recover the waste heat again;

a cooling medium inlet is arranged in the coke poking device 19, and cold coal gas entering the cooling medium inlet absorbs sensible heat of coke above 100 ℃ to efficiently cool the coke, and rises to enter the single-hole joint-pass medium-low temperature dry quenching heat exchanger 17 to fully exchange heat with hot coke in a coke pass; after absorbing the heat of the coke in the middle and low temperature section, continuously rising to enter a single-hole joint high-temperature dry quenching section 15, and exchanging heat with the high-temperature red hot coke and continuously raising the temperature; when reaching the top of the single-hole coupled high-temperature dry quenching section 15 and the braising section 12, the coke is subjected to heat exchange with red hot coke which continuously descends continuously at a temperature of more than 950 ℃, and the single-hole coupled dry quenching devices 17 and 15 play a role in strengthening and cooling the coke; and finally, the gas rises to enter the high-temperature pyrolysis section 9 to be mixed with the hydrogen-rich gas pyrolyzed in the high-temperature pyrolysis section, the mixed hydrogen-rich gas is led out through the high-temperature gas outlet 23, and then the gas enters the working procedures of gas purification, synthesis, separation and the like.

Although the utility model has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the utility model. Accordingly, such modifications and improvements are intended to be within the scope of the utility model as claimed.

Claims

1. A device for continuously extracting oil gas from medium and low-rank coal is characterized by comprising a storage bin, a sealed coal charging device, a prestoring section, a drying preheating section, a multi-stage gradient heating pyrolysis section, a coke stewing section, a single-hole linked-path dry quenching section, a coke pushing device and a sealed coke discharging machine which are sequentially connected from top to bottom;

the multi-stage gradient heating pyrolysis section comprises more than three continuous stages, and each stage is respectively connected with a coal gas outlet;

the device also comprises a heating section for indirectly supplying heat to the multi-stage gradient heating pyrolysis section.

2. The apparatus of claim 1, wherein the heating section is directly adjacent to the multi-stage gradient-ramp pyrolysis section, including a one-to-one heating stage for each pyrolysis stage;

an air inlet and a combustible gas inlet are formed in the bottom of the heating section; the air inlet is connected with the air channel, and the combustible gas inlet is connected with the return gas pipeline;

the heating section is also provided with a waste gas outlet which is connected with a waste gas channel positioned below the heating section.

3. The apparatus of claim 2, wherein the single-hole coupled pass dry quenching section comprises, from top to bottom, a connected single-hole coupled pass high temperature dry quenching section and a single-hole coupled pass medium and low temperature dry quenching heat exchanger;

the air channel is positioned between the single-hole linked high-temperature dry quenching section and the waste gas channel and is respectively and directly adjacent to the single-hole linked high-temperature dry quenching section and the waste gas channel.

4. The apparatus according to any one of claims 1 to 3, wherein the decoking apparatus is provided with a cooling medium inlet.

5. The apparatus of claim 4, wherein the cooling medium entering the cooling medium inlet is cold gas.

6. The device according to any one of claims 1 to 3, wherein a water atomizer is arranged in the coke poking device; the water vapor which is atomized by the water atomizer and directly exchanges heat with the coke passes through a single-hole joint pass dry quenching section, a coke stewing section and a multi-stage gradient temperature rise pyrolysis section in sequence, and the generated water gas is taken as a product and is led out from a gas outlet.

7. The apparatus according to any one of claims 1 to 3, wherein the multi-stage gradient-temperature-rise pyrolysis section consists of three stages, namely a low-temperature pyrolysis section, a medium-temperature pyrolysis section and a high-temperature pyrolysis section.

8. The device according to any one of claims 1 to 3, wherein the device for continuously extracting oil gas from the medium and low-rank coals is fully sealed; wherein, the coke poking device controls the descending speed of the material.