CN102634395A - Process and system for purifying and refining coal-bed gas - Google Patents
Process and system for purifying and refining coal-bed gas Download PDFInfo
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- CN102634395A CN102634395A CN2012101216428A CN201210121642A CN102634395A CN 102634395 A CN102634395 A CN 102634395A CN 2012101216428 A CN2012101216428 A CN 2012101216428A CN 201210121642 A CN201210121642 A CN 201210121642A CN 102634395 A CN102634395 A CN 102634395A
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- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0228—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream
- F25J3/0233—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream separation of CnHm with 1 carbon atom or more
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- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0204—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the feed stream
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- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0228—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream
- F25J3/0257—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream separation of nitrogen
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- F25J2200/00—Processes or apparatus using separation by rectification
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- F25J2200/00—Processes or apparatus using separation by rectification
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- F25J2200/00—Processes or apparatus using separation by rectification
- F25J2200/90—Details relating to column internals, e.g. structured packing, gas or liquid distribution
- F25J2200/94—Details relating to the withdrawal point
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- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
- F25J2205/04—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum in the feed line, i.e. upstream of the fractionation step
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- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
- F25J2205/66—Regenerating the adsorption vessel, e.g. kind of reactivation gas
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- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/40—Air or oxygen enriched air, i.e. generally less than 30mol% of O2
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- F25J2215/00—Processes characterised by the type or other details of the product stream
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- F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
- F25J2230/30—Compression of the feed stream
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- F25J2240/00—Processes or apparatus involving steps for expanding of process streams
- F25J2240/40—Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
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- F25J2270/00—Refrigeration techniques used
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- F25J2270/00—Refrigeration techniques used
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Abstract
The invention relates to a system for purifying and refining coal-bed gas, and the system for purifying and refining the coal-bed gas is used for solving the problems of high cost, high energy consumption and adversity to environmental protection of the existing coal-bed gas purification process. The system comprises a purification system, a pressurization and refrigeration system and a cryogenic distillation system; the purification system comprises a filter, a compressor, a washing tower and an adsorption system which are sequentially connected with one another; the pressurization and refrigeration system comprises a supercharger and a high-pressure heat exchanger; the cryogenic distillation system comprises a separator, a subcooler, a throttle valve and a cryogenic distillation tower; and the adsorption system is sequentially connected with the supercharger, the high-pressure heat exchanger, the separator, the throttle valve and the cryogenic distillation tower. The system for purifying and refining the coal-bed gas has the advantages of simple equipment, simplification of production process, more simplicity and convenience in system control, low cost for equipment investment and operation, short production period and high recovery ratio and purity of produced finished natural gas products, is applicable to coal-bed gases with different methane contents and has broad market application prospect.
Description
Technical field
The present invention relates to a kind of fuel gas field of purification, a kind of specifically coal-seam gas purifying technology and system.
Background technology
Coal-seam gas is commonly called as coal-mine gas, i.e. Sweet natural gas.It is and coal association, symbiotic gas resource, and its staple is a methane, and methane content is generally 15%～70%.Brown coal per ton can generate 38～50 cubic metres of coal-seam gas, and hard coal can generate 346～422 cubic metres of coal-seam gas.By calorific value calculation, the calorific value of methane is 33.5～33.7kJ/Nm
3(8000～9000kcal/Nm
3), more taller than the thermal value of 1 kilogram of standard coal equivalent.
The typical case of coal-seam gas forms as shown in table 1.
The typical case of table 1 coal-seam gas forms
Coal-seam gas not only can be used for fuel used to generate electricity, industrial fuel and resident living fuel, and the back of can also liquefying is as automobile fuel; Also can be widely used in the raw material of Chemicals such as producing synthetic ammonia, formaldehyde, methyl alcohol, as a kind of calorific value high clear energy sources and important industrial chemicals, prospect is very wide.
Original adopt coal-seam gas can not directly use, need fully to remove, and then obtain purified methane product through low temperature separation process to the impurity such as dust, moisture content, carbonic acid gas, hydrogen sulfide and hydrocarbon polymer that wherein contain.
Coal-seam gas purifying technology has multiple at present; A kind of coal gas gasification rectificating method is disclosed like patent CN101922849A; Refrigeration techniques in its liquefaction separation circuit adopts double expansion machine expansion cooling precooling; Provide cold to carry out secondary cooling by the reboiler at the bottom of the rectifying Tata again, have that separation purity is higher, the simple advantage of apparatus structure.There is following shortcoming in this process method:
1) adopt two stages of compression+reboiler refrigeration, its refrigeration is relatively poor, must carry out the secondary cooling; And the secondary cooling receives the external world that the restriction of cold is provided, and seek out high separation purity, and extraneous the need provides enough colds to reboiler; Thereby increased running cost, be unfavorable for saving energy and reduce the cost;
2) still be exhausted from system after the foreign gas cold recovery that rectifying tower is discharged, handling these tail gas not only needs expensive treating plant, also is unfavorable for environment protection.
Summary of the invention
To the objective of the invention is in order solving the problems of the technologies described above, to provide that a kind of technology is simple, good refrigeration effect, energy-saving and cost-reducing, the low coal-seam gas purifying technology of investment running cost.
The present invention also provides the coal-seam gas purifying system that realizes above-mentioned process method.
Technology of the present invention is for comprising the steps:
One, purifying step: coal-seam gas is carried out dustiness≤20mg/Nm that the dedusting washing makes coal-seam gas earlier
3, send into adsorption system then after the supercharging and adsorb, to remove the impurity in the coal-seam gas;
Two, pressurization refrigeration step: will after the further supercharging of the coal-seam gas after the purifying step, send into the high pressure heat exchanger heat exchange and be cooled to-135 ℃ to-155 ℃; Three, low temperature separation process step: the coal-seam gas after the heat exchange is sent into separator; Isolated liquid phase and gas phase get into the rectifying of cryogenic rectification tower after the throttling valve throttling, obtain being discharged by the cryogenic rectification top of tower side line gas phase, the bottom discharge liquefied natural gas of dirty nitrogen, side line discharge after the rectifying.
In the said step 1, earlier coal-seam gas is sent into and filtered gas and remove the macrobead dust that particle diameter is 5～200 μ m, and then get into washing tower and advance to remove fine particle dust in the coal-seam gas, after washing, coal-seam gas dustiness≤20mg/Nm
3
In the said step 2, the medium that in high pressure heat exchanger, carries out heat exchange with said coal-seam gas comprises dirty nitrogen, side line gas phase and refrigeration working medium from the cryogenic rectification tower.
In the said step 2, said cryogenic rectification top of tower is discharged dirty nitrogen and after the high pressure heat exchanger heat exchange, is sent into adsorption system and use nitrogen as adsorption system regeneration.
In the said step 2; After sending into the pressurized end supercharging of booster expansion turbine, gas mixture sends into high pressure heat exchanger and coal-seam gas heat exchange through mixing to form with refrigeration working medium after the high pressure heat exchanger re-heat from the side line gas phase of said cryogenic rectification tower; Send back to then booster expansion turbine the expanding end isentropic expansion, and to the acting of the pressurized end of booster expansion turbine.
In the said step 2, said after isentropic expansion gas mixture again through the high pressure heat exchanger re-heat, and with the pressurized end of sending into booster expansion turbine from the side line gas phase mixed cycle of cryogenic rectification tower.
In the said step 3, the liquid phase that said separator separates goes out gets into the rectifying of cryogenic rectification tower after the throttling valve throttling; Gas phase gets into the rectifying of cryogenic rectification tower again after the throttling valve throttling in supercooler with after the dirty nitrogen heat exchange of discharging from the cryogenic rectification top of tower.
Coal-seam gas purifying of the present invention system comprises purification system, pressurization refrigeration system and cryogenic rectification system, and said purification system comprises strainer, compressor, washing tower and the adsorption system that connects successively; Said pressurization refrigeration system comprises supercharger and high pressure heat exchanger; Said cryogenic rectification system comprises separator, supercooler, throttling valve and cryogenic rectification tower; Said adsorption system connects supercharger, high pressure heat exchanger, separator and throttling valve and cryogenic rectification tower successively.
Said cryogenic rectification system also includes supercooler; Said throttling valve comprises the first throttle valve and second throttling valve; The top gaseous phase outlet of said separator is connected with the cryogenic rectification tower through supercooler, first throttle valve, and the bottom liquid phases outlet is connected with the cryogenic rectification tower through second throttling valve.
The top exit of said cryogenic rectification tower is connected with the regeneration adsorption system through supercooler, high pressure heat exchanger.
Said pressurization refrigeration system also comprises booster expansion turbine; The side line outlet of said cryogenic rectification tower is connected with the pressurized end inlet of booster expansion turbine through high pressure heat exchanger; The pressurized end outlet of said booster expansion turbine is connected with the expanding end inlet of booster expansion turbine through high pressure heat exchanger again, and the expanding end outlet of said booster expansion turbine is connected with the pressurized end inlet of booster expansion turbine through high pressure heat exchanger.
The contriver furthers investigate coal-seam gas, has made following innovation:
In the purifying step, water cut is low in the coal-seam gas, can directly carry out the dry method ash disposal; Utilize strainer to remove the macrobead dust earlier; Remove the fine dust in the thick coal-seam gas through washing tower again, good dedusting effect, efficient are high, have improved the quality of coal-seam gas; The dry method ash disposal not only reduces the waste of water resources, and the macrobead dry coal ash that obtains also has better economic and is worth; Adopt adsorption system can effectively remove the impurity such as moisture, carbonic acid gas, hydrogen sulfide and hydrocarbon polymer in the coal-seam gas; Guarantee the decontamination effect improving of coal-seam gas; And; Regeneration in the adsorption system also can be used dirty nitrogen after the re-heat that the cryogenic rectification top of tower in the subsequent step discharges with nitrogen, has further saved investment, has reduced the discharging of tail gas.Said sorbent material can use the sorbent material of renewable recycles such as molecular sieve or silica gel.
In the pressurization refrigeration step; Having abandoned the relatively poor traditional isenthalpic throttling of refrigeration expands; Adopt isentropic expansion-compression cycle work done principle; Use booster expansion turbine, utilize circulation and next gas mixture (comprising refrigeration working medium and side line gas phase) isentropic expansion in the expanding end of booster expansion turbine, and the booster expansion turbine pressurized end is done work; Pass through the high pressure heat exchanger re-heat then; Gas phase mixed cycle to the booster expansion turbine pressurized end that comes out with cryogenic rectification tower 12 side lines again, dirty nitrogen in the top that the cryogenic rectification tower comes out and side line gas phase all reclaim cold in high pressure heat exchanger, and the gas mixture after booster expansion turbine pressurization refrigeration also repeatedly reclaims cold in high pressure heat exchanger in working cycle simultaneously; Make coal-seam gas in high pressure heat exchanger, cool off rapidly, reach the purpose of the minimal loss of refrigerating maximum efficiency and cold.Said refrigeration working medium only adds when going into operation and gets final product; After treating normal operation; Also be blended into circulation jointly in the refrigeration working medium after the side line gas phase re-heat that cryogenic rectification tower side line is discharged, the inevitable internal circulating load loss to exist in the replenishment cycles process guarantees booster expansion turbine compression refrigeration efficient; Make cold offer coal-seam gas to greatest extent; Make the coal gas layer after going out high pressure heat exchanger, just can reach-135 ℃ to-155 ℃,, thereby be implemented in preliminary gas phase and the liquid phase separation in the separator near the dew-point temperature of methane.Further, send into high pressure heat exchanger again after preferred coal-seam gas is pressurized to 1.5MPag～3.5MPag, pressure can make the dew-point temperature of methane raise down, more is prone to make the coal-seam gas after cooling in subsequent step three, gas-liquid separation to take place.
Further, in the low temperature separation process step, isolating gas phase and liquid phase were utilized throttling valve two-step throttle swell refrigeration before getting into the cryogenic rectification tower, and further giving provides cold, guarantees to obtain the high-recovery and the high cleanliness of liquefied natural gas.And gas phase reaches the purpose of abundant recovery cold also through the dirty nitrogen heat exchange of supercooler and the discharge of cryogenic rectification top of tower.
Among the present invention, dirty nitrogen is meant that nitrogen content surpasses the gas of percent by volume 75%; The separation method of two strands of materials of side line gas phase of dirty nitrogen of said cryogenic rectification top of tower and side line for a person skilled in the art, can be bled through the column plate of the different numbers of plies in the cryogenic rectification tower or height on the technology and realize.
Taken all factors into consideration the maximization of energy recovery and utilization in the technology of the present invention, adopted the principle of " one-level isentropic expansion refrigeration cooperates the throttling expansion refrigeration " on the technology, refrigerating efficiency is high and realize self-circulation fully; Need not to replenish new cold and refrigeration working medium; Be truly energy-saving and cost-reducing, and make full use of the tail gas of discharge, make it rationally to be back to use in the system; Thereby reach whole process tail gas near zero release, environment amenable purpose.The present invention has simplified that production technique, system's system control are more easy, facility investment and running cost are low, with short production cycle; The finished product gas product recovery and the high purity produced; Be applicable to the coal-seam gas of different methane contents, have wide market application prospect.With certain project is example, 100,000 Nm
3The coal-seam gas treatment capacity of/d; The about 43.81vol% of methane content; Adopt system of the present invention to compare than prior art; Facility investment can reduce by 4,000,000 yuan, and running cost can descend about 1,600,000 yuan/year (being mainly the energy-saving and cost-reducing cost that brings descends), can produce 0.891 ten thousand ton high-quality gas product (CH every year
4＞95vol%).
Description of drawings
Figure 1 is a system diagram snuff process of the invention process.
Wherein: 1-strainer, 2-compressor, 3-washing tower, 4-adsorption system, 5-supercharger, 6-booster expansion turbine, 6.1-booster expansion turbine pressurized end, 6.2-booster expansion turbine expanding end, 7-high pressure heat exchanger, 8-separator, 9-supercooler, 10,11-throttling valve, 12-cryogenic rectification tower, 13-Sweet natural gas basin.
Embodiment
Below in conjunction with accompanying drawing system of the present invention is further explained: comprise purification system, pressurization refrigeration system and cryogenic rectification system, said purification system comprises strainer 1, compressor 2, washing tower 3 and adsorption system 4; Said pressurization refrigeration system comprises supercharger 5, high pressure heat exchanger 7 and booster expansion turbine 6; Said cryogenic rectification system comprises separator 8, supercooler 9, first throttle valve 10, second throttling valve 11 and cryogenic rectification tower 12.Concrete annexation is: connect compressor 2, washing tower 3, adsorption system 4, increase machine 5, high pressure heat exchanger 7 and separator 8 successively by strainer 1, the top exit of said separator 8 gets into the epimere opening for feed of cryogenic rectification tower 12 through supercooler 9, first throttle valve 10; The outlet at bottom of said separator 8 gets into the epimere opening for feed of cryogenic rectification tower 12 through second throttling valve 11; The outlet at bottom of said rectifying tower 12 connects Sweet natural gas basin 13, and top exit is connected with regeneration adsorption system 4 through supercooler 9, high pressure heat exchanger 7, uses nitrogen to regenerate as adsorption system 4 behind the dirty nitrogen recycling cold that will discharge.Said cryogenic rectification tower 12 side lines outlet is connected through the inlet of high pressure heat exchanger 7 with booster expansion turbine pressurized end 6.1; The outlet of booster expansion turbine pressurized end 6.1 is connected with booster expansion turbine expanding end 6.2 inlets through high pressure heat exchanger 7, and 6.2 outlets of booster expansion turbine expanding end are connected through the inlet of high pressure heat exchanger 7 with booster expansion turbine pressurized end 6.1.
Process method is:
Embodiment 1:
Coal-seam gas (the coal-seam gas composition is seen table 1) is through the macrobead dust of coal-seam gas strainer 1 elimination 5～200 μ m;, coal-seam gas compressor 2 gets into washing tower 3 after being forced into 0.5MPag～3.0MPag; Coal-seam gas is removed thin dirt with circulation cleaning water counter current contact in washing tower 3; After washing, coal-seam gas dustiness≤20mg/Nm
3, get into adsorption system 4 then, impurity such as the moisture in the adsorption removal coal-seam gas, carbonic acid gas, hydrogen sulfide and hydrocarbon polymer, the regeneration in the adsorption system is used the next dirty nitrogen by 12 circulations of cryogenic rectification tower with nitrogen; Said sorbent material uses the sorbent material that can use renewable recycles such as molecular sieve or silica gel.
The coal-seam gas that has purified imports coal-seam gas supercharger 5 and is pressurized to 1.5MPag～3.5MPag; Get into high pressure heat exchanger 7 then; In high pressure heat exchanger 7 simultaneously and round-robin refrigeration working medium, returning polluted nitrogen gas and side line gas phase discharging heat exchange, be cooled to-135 ℃ to-155 ℃ after entering separator 8.The gas-liquid separation in separator 8 of cooled coal-seam gas; (pressure is reduced to the epimere opening for feed that 0.05MPag～0.5MPag) removes cryogenic rectification tower 12 to liquid phase through second throttling valve 11 throttlings; Gas phase reclaims the part cold (heat exchange) of dirty nitrogen earlier through supercooler 9; (pressure is reduced to 0.05MPag～0.5MPag) and is got into cryogenic rectification tower 12 epimere opening for feeds through 10 throttlings of first throttle valve again; Gas phase and the liquid phase of coal-seam gas after separating after the rectifying, obtains natural gas liquids, dirty nitrogen and side line gas phase in cryogenic rectification tower 12.
The natural gas liquids that comes out in cryogenic rectification tower 12 bottoms removes natural gas liquids basin 13.
(dirty nitrogen is by extracting out in first block of column plate in the present embodiment, and the major ingredient percent by volume is N for the dirty nitrogen that comes out in cryogenic rectification tower 12 tops
2Account for 85.8%mol, O
2Account for 8.4%mol, CH
4Account for 5.8%mol), behind the gas phase heat exchange recovery part cold through supercooler 9 and the cold rectifying tower 12 of depth, go high pressure heat exchanger 7 re-heats (with the coal-seam gas heat exchange) back loopback adsorption system 4 again, use nitrogen as adsorption system 4 regeneration.
(the side line gas phase is by extracting out in the tenth block of column plate in the present embodiment, and the major ingredient percent by volume is N for the side line gas phase that cryogenic rectification tower 12 side lines come out
2Account for 39.2%mol, O
2Account for 45%mol, CH
4Account for 15.8%mol) after high pressure heat exchanger 7 re-heats (with the coal-seam gas heat exchange), mix with refrigeration working medium gas.
Refrigeration cycle process among the present invention is: when going into operation; Refrigeration working medium is through the compression of booster expansion turbine pressurized end 6.1; Get into high pressure heat exchanger 7 and carry out heat exchange, remove booster expansion turbine expanding end 6.2 after the cooling, refrigeration working medium isentropic expansion in booster expansion turbine expanding end 6.2 with coal-seam gas; And to 6.1 actings of booster expansion turbine pressurized end; Continue and the coal-seam gas heat exchange, and the same formation gas mixture that high pressure heat exchanger 7 in, mixes that comes out with cryogenic rectification tower 12 side lines loopback high pressure heat exchangers 7 after gas mixture is recycled to booster expansion turbine pressurized end 6.1 and compresses then with the side line gas phase of coal gas layer heat exchange through high pressure heat exchanger 7.This working cycle continues to carry out, and provides enough colds to make the coal-seam gas through high pressure heat exchanger 7 be cooled to-135 ℃ to-155 ℃.In this technology; Disposable importing internal circulating load got final product when refrigeration working medium only need go into operation; Loss amount during operation can be replenished by the side line gas phase; Said refrigeration working medium can adopt existing refrigeration working mediums commonly used such as nitrogen or mix refrigerant such as nitrogen+methane, nitrogen+ethane, nitrogen+propane, is not particularly limited here.
The recovery that finally obtains liquefied natural gas product is 93.2%, and purity is 95.7%mol.
Embodiment 2
Coal-seam gas is formed as shown in table 2.
Table 2 coal-seam gas is formed
Process method is with embodiment 1, and the recovery that finally obtains liquefied natural gas product is 91.8%, and purity is 96.9%mol.
Embodiment 3
Coal-seam gas is formed as shown in table 2.
Table 3 coal-seam gas is formed
Process method is with embodiment 1, and the recovery that finally obtains liquefied natural gas product is 97.5%, and purity is 99.5%mol.
Claims (11)
1. a coal-seam gas purifying technology is characterized in that, comprises the steps:
One, purifying step: coal-seam gas is carried out dustiness≤20mg/Nm that the dedusting washing makes coal-seam gas earlier
3, send into adsorption system then after the supercharging and adsorb, to remove the impurity in the coal-seam gas;
Two, pressurization refrigeration step: will after the further supercharging of the coal-seam gas after the purifying step, send into the high pressure heat exchanger heat exchange and cool to-135 ℃ to-155 ℃; Three, low temperature separation process step: the coal-seam gas after the heat exchange is sent into separator; Isolated liquid phase and gas phase get into the rectifying of cryogenic rectification tower after the throttling valve throttling, obtain being discharged by the cryogenic rectification top of tower side line gas phase, the bottom discharge liquefied natural gas of dirty nitrogen, side line discharge after the rectifying.
2. coal-seam gas purifying LNG technology as claimed in claim 1; It is characterized in that; In the said step 1, earlier coal-seam gas is sent into filtration gas and remove the macrobead dust that particle diameter is 5～200 μ m, and then the entering washing tower advances to remove fine particle dust in the coal-seam gas; After washing, coal-seam gas dustiness≤20mg/Nm
3
3. coal-seam gas purifying technology as claimed in claim 1 is characterized in that, in the said step 2, the medium that in high pressure heat exchanger, carries out heat exchange with said coal-seam gas comprises dirty nitrogen, side line gas phase and refrigeration working medium from the cryogenic rectification tower.
4. coal-seam gas purifying technology as claimed in claim 3 is characterized in that, in the said step 2, said cryogenic rectification top of tower is discharged dirty nitrogen and after the high pressure heat exchanger heat exchange, sent into adsorption system and use nitrogen as adsorption system regeneration.
5. like each described coal-seam gas purifying technology of claim 1-4; It is characterized in that; In the said step 2; Send into high pressure heat exchanger and coal-seam gas heat exchange through mixing to form with refrigeration working medium after the high pressure heat exchanger re-heat after gas mixture is sent into the pressurized end supercharging of booster expansion turbine from the side line gas phase of said cryogenic rectification tower, send the expanding end isentropic expansion of booster expansion turbine then back to, and the pressurized end of booster expansion turbine is done work.
6. coal-seam gas purifying technology as claimed in claim 5; It is characterized in that; In the said step 2, said gas mixture after isentropic expansion again through the high pressure heat exchanger re-heat and with the pressurized end of sending into booster expansion turbine from the side line gas phase mixed cycle of cryogenic rectification tower.
7. coal-seam gas purifying technology as claimed in claim 1 is characterized in that, in the said step 3, the liquid phase that said separator separates goes out gets into the rectifying of cryogenic rectification tower after the throttling valve throttling; Gas phase gets into the rectifying of cryogenic rectification tower again after the throttling valve throttling in supercooler with after the dirty nitrogen heat exchange of discharging from the cryogenic rectification top of tower.
8. a coal-seam gas purifying system is characterized in that, comprises purification system, pressurization refrigeration system and cryogenic rectification system, and said purification system comprises strainer, compressor, washing tower and the adsorption system that connects successively; Said pressurization refrigeration system comprises supercharger and high pressure heat exchanger; Said cryogenic rectification system comprises separator, supercooler, throttling valve and cryogenic rectification tower; Said adsorption system connects supercharger, high pressure heat exchanger, separator and throttling valve and cryogenic rectification tower successively.
9. coal-seam gas purifying as claimed in claim 8 system; It is characterized in that; Said cryogenic rectification system also includes supercooler; Said throttling valve comprises the first throttle valve and second throttling valve, and the top gaseous phase outlet of said separator is connected with the cryogenic rectification tower through supercooler, first throttle valve, and the bottom liquid phases outlet is connected with the cryogenic rectification tower through second throttling valve.
10. coal-seam gas purifying as claimed in claim 9 system is characterized in that the top exit of said cryogenic rectification tower is connected with the regeneration adsorption system through supercooler, high pressure heat exchanger.
11. like each described coal-seam gas purifying system of claim 8-10; It is characterized in that; Said pressurization refrigeration system also comprises booster expansion turbine; The side line outlet of said cryogenic rectification tower is connected with the pressurized end inlet of booster expansion turbine through high pressure heat exchanger; The pressurized end outlet of said booster expansion turbine is connected with the expanding end inlet of booster expansion turbine through high pressure heat exchanger again, and the expanding end outlet of said booster expansion turbine is connected with the pressurized end inlet of booster expansion turbine through high pressure heat exchanger.
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| CN103146449A (en) * | 2013-02-25 | 2013-06-12 | 中煤科工集团重庆研究院 | Technology for making LNG (Liquefied Natural Gas) from low-concentration coal bed gas through pressure swing adsorption and cryogenic liquefaction |
| CN103361138A (en) * | 2013-07-24 | 2013-10-23 | 开封黄河空分集团有限公司 | Method for preparing liquefied natural gas and synthesis ammonia raw material gases by use of hydrogen extraction desorption gas |
| CN104194853A (en) * | 2014-07-04 | 2014-12-10 | 韩俊义 | Device and process for preparing LNG by purifying oxygen-containing coal bed gas with methane content of 15-40% |
| CN109294647A (en) * | 2018-09-17 | 2019-02-01 | 广州智光节能有限公司 | The purification system of natural gas |
| CN114749004A (en) * | 2022-04-29 | 2022-07-15 | 中联煤层气国家工程研究中心有限责任公司 | High-efficiency coal bed gas liquefaction system and method |
| RU2808604C1 (en) * | 2023-06-16 | 2023-11-30 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Кубанский государственный технологический университет" (ФГБОУ ВО "КубГТУ") | Gas adsorption unit |
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| CN103146449A (en) * | 2013-02-25 | 2013-06-12 | 中煤科工集团重庆研究院 | Technology for making LNG (Liquefied Natural Gas) from low-concentration coal bed gas through pressure swing adsorption and cryogenic liquefaction |
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| CN114749004A (en) * | 2022-04-29 | 2022-07-15 | 中联煤层气国家工程研究中心有限责任公司 | High-efficiency coal bed gas liquefaction system and method |
| CN114749004B (en) * | 2022-04-29 | 2023-01-31 | 中联煤层气国家工程研究中心有限责任公司 | Coal bed gas efficient liquefaction system and method |
| RU2808604C1 (en) * | 2023-06-16 | 2023-11-30 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Кубанский государственный технологический университет" (ФГБОУ ВО "КубГТУ") | Gas adsorption unit |
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