A kind of methanol waste gas recovery system
Technical field
The present invention relates to methanol waste gas recovery technology field, relate to a kind of methanol waste gas recovery system, be related specifically to one and " absorb+adsorb " integrated high efficiency methanol gas recovery method and device thereof.
Background technology
When methyl alcohol entrucking is dropped a hint, a large amount of methyl alcohol and air gas mixture can be given off.If this mist is directly discharged in air, not only cause environmental pollution and energy waste, also may bring disaster hidden-trouble, bring hidden danger to people life property safety.After taking methanol waste gas to reclaim, the methyl alcohol of more than 95% is recovered, and greatly reduces methyl alcohol and escapes, and improves the operating environment in entrucking place well, and overcomes the potential safety hazard that methanol emissions brings.And the methyl alcohol after reclaiming can directly flow to user or barrelling, remarkable in economical benefits.
Retrieved domestic and foreign databases according to the technology of the present invention feature, find that the patent that relevant methanol waste gas reclaims is less.Such as, Chinese patent CN200910075020.4 mentions and utilizes absorption process to reclaim methanol waste gas in vitamin C producing process, and absorbent is the mixed thing of water, alcohol compound, and this invention weak point is: the tail gas after the method reclaims is high containing methanol concentration; Chinese patent CN102380288A refer to a kind of oil-gas recovery method and device of absorption-adsorbing integration technology, and this invention weak point is: the oil gas absorbing agent development difficulty used by the method is large, cost is high, is not suitable for methanol waste gas and reclaims.Through retrieval, also do not use " absorbing+absorption " integrated recovery methyl alcohol at present and utilize water to absorb the technology of methanol waste gas as absorbent.
Summary of the invention
The present invention, for solving the problems such as energy resource consumption is large, the rate of recovery is low in methanol waste gas recovery system, develops and a kind ofly collects efficient, the integrated reclaimer absorbing and be adsorbed in one, and proposes and directly utilize water to absorb methanol waste gas.
(1) technical scheme of the present invention is as follows:
Methanol waste gas " absorbs+absorption ", and recovery system comprises: blower fan, absorption tower, frequency conversion explosion proof water pump, adsorption tower A, adsorption tower B, vavuum pump, control system, data acquisition process and the accessory such as gas analysis work station and flowmeter, liquid level gauge, pressure sensor, temperature sensor, valve, spark arrester and pipeline.
The blower fan of recovery system that 1. described methanol waste gas " absorbs+absorption " is frequency conversion explosion proof blower fan, according to admission pressure size, carry out variable frequency adjustment rotation speed of fan by pressure sensor, thus control blower fan absorbing quantity, general setting admission pressure is not less than-500Pa (gauge pressure).
Pipe distributor, groove type distributor or tube and tank type distributor can be arranged in the absorption tower main body of recovery system that 2. described methanol waste gas " absorbs+absorption ", absorption tower main body arranges liquid level gauge, several temperature sensors and pressure sensor along absorption tower short transverse.
Further, described absorption tower height is determined according to treating capacity, is generally 1 ~ 15m, and diameter is 0.5 ~ 2m.
Further, the absorbent in described absorption tower is water.
Further, described coolant-temperature gage < 35 DEG C, flow is 1 ~ 10t/h, and sprinkle density is 0.32 ~ 50.96m
3/ (m
2h).
Further, the liquid level of described liquid level gauge controls the flow of frequency conversion explosion proof water pump, thus it is effectively moderate that guarantee is sprayed.
Further, described absorption equipment absorptivity is 70% ~ 90%.
Adsorption tower A, B main body of recovery system that 3. described methanol waste gas " absorbs+absorption " arranges several temperature sensors and pressure sensor along adsorption tower A, B short transverse.
Further, described adsorption tower A, B are highly 1 ~ 10m, and diameter is 0.5 ~ 2.5m.
Further, described adsorption tower A, B diameter is determined by formula (1), and described adsorption tower A, B height is determined by formula (2):
In formula:
The filling diameter of D---active carbon, m;
Q---the charge flow rate of methyl alcohol-air Mixture, m
3/ s (STP);
The empty tower gas velocity of ν---fixed-bed adsorber, generally gets 0.1 ~ 0.3m/s;
The packed height of H---active carbon, m;
C
in---methanol gas molar fraction in charging, mol/mol;
τ---charcoal absorption time, s;
η---methanol gas (quality) rate of recovery, %;
ρ---active carbon packed density, kg/m
3;
Q---charcoal absorption capacity, g (methanol gas)/g (charcoal).
Further, general adsorption tower height diameter ratio H/D=2 ~ 4, if H/D exceedes should suitably adjust H, D value.
Further, the adsorbent loaded in described adsorption tower A, B is active carbon, silica gel, dewatering silica gel, resin, zeolite, AdsFOV-II, Composite Adsorbent Absorbing agent.
The vavuum pump of recovery system that 4. described methanol waste gas " absorbs+absorption " is dry vacuum pump.
Further, described dry vacuum pump vacuum is at more than 85kPa.
The control system of recovery system that 5. described methanol waste gas " absorbs+absorption " automatically controls the power-equipment of whole recovery system, to carry out gas collection, absorption and sorption and desorption operations in good time.
The data acquisition process of recovery system that 6. described methanol waste gas " absorbs+absorption " and gas analysis work station be by on-line monitoring air hatch, absorption tower, in adsorption tower, the data such as the exhaust gas concentration of exhaust outlet determine absorption and sorption, desorption operations.
Methanol waste gas " absorbs+adsorbs " recovery system by above-mentioned methanol waste gas, can realize methanol waste gas qualified discharge (as " petro chemical industry pollutant emission standard " GB31571-2015 requires tail gas methanol concentration < 50mg/m
3).
(2) recovery method of methanol waste gas " absorption+absorption " recovery system is:
1. scene is carried out gas (from the methanol-air gaseous mixture that the process such as groove tank car or tank wagon entrucking emptying produces, gas flow is 100 ~ 1500Nm
3/ h, gas temperature is normal temperature (environment temperature), and mist methanol concentration is 0.05 ~ 500g/m
3) utilize blower fan to guide to collecting pipe, through spark arrester, pressure sensor, temperature sensor, control valve, flowmeter, enter absorption tower from the combi inlet port the main body of absorption tower.This mist flows from bottom to top in absorption tower.Meanwhile, pure water by control valve, flowmeter to top, structured packing absorption tower, the methanol vapor of most of (70% ~ 90%) absorb by water.
2. from top, absorption tower out (be generally less than 70g/m containing a small amount of methanol vapor
3) and a small amount of steam (be generally less than 50g/m
3) tail gas through pressure sensor, temperature sensor, self-priming concentration air hatch, control valve, then the combi inlet port passed under adsorption tower A (or B) main body and by adsorption tower A (or B) absorption recycling.From adsorption tower A (or B) top gaseous mixture out through temperature sensor, pressure sensor, self-priming concentration air hatch, control valve, spark arrester, enter that tail gas blow-down pipe is up to standard enters air.
3. when from adsorption tower A (or B) top out the methanol concentration that gathers at self-priming concentration air hatch of tail gas (as tail gas concentration > 50mg/m
3) when not meeting the demands, the control valve connected adsorption tower A (or B) main body top and the bottom by automatic control system is closed, and opens the control valve that adsorption tower B (or A) main body top and the bottom connect.
4. the water after absorbing methanol waste gas in absorption tower is delivered to owner by frequency conversion explosion proof water pump and is carried out water treatment.
5. when adsorption tower A (or B) stops absorption work, open control valve that adsorption tower A (or B) is connected with vavuum pump by automatic control system, start vavuum pump, the adsorbent solution after absorption methyl alcohol is made to be drawn onto setting-up time (20 ~ 60min, concrete desorption time adjusts according to during debugging again, determines), when vavuum pump runs last 5 ~ 10min, open the control valve that adsorption tower A (or B) is connected with nitrogen pipeline and automatically pass into nitrogen, promote desorb.After vavuum pump quits work, close the control valve that adsorption tower A (or B) is connected with vavuum pump, continue to pass into nitrogen until adsorption tower A (or B) interior pressure is normal pressure, close the control valve that adsorption tower A (or B) is connected with nitrogen pipeline.
Technique effect of the present invention is:
(1) the present invention's high efficiency methanol gas recovery method of adopting " absorb+absorption " integrated, while utilizing two kinds of method advantages, effectively overcomes adsorbent heat, and extend adsorbent service life, security is good.Solve the key issue that exhaust emissions concentration is not up to standard.
(2) the present invention utilizes water to absorb methanol waste gas, and energy consumption is lower.
(3) adsorption tower of the present invention is set to two, can carry out automatic switchover absorption, ensure the continuity reclaimed.
(4) in removal process, concentration, temperature, flow and pressure all carry out online acquisition, line analysis is stood in by data acquisition process and gas analytical work, instruct and when carry out gas collection, absorption and sorption and desorption operations, and utilize automatic controlling system gas collection, absorption and sorption and desorption operations.
Accompanying drawing explanation
Accompanying drawing 1 methanol waste gas " absorbs+adsorbs " recovery process flow chart
Reference numeral lists as follows:
1,38-spark arrester, 2,8,12,19,21,31-pressure sensor, 3,9,17,22,32-temperature sensor, 4,5,11,13,15,23,24,25,27,28,34,35,36-control valve, 41,43-ball valve, 6-blower fan, 7-frequency conversion explosion proof water pump, 20-vavuum pump, 10,16-flowmeter, 42-liquid level gauge, 18,29,30,37-self-priming concentration air hatch, 14-absorption tower, 26,33-adsorption tower, 39-control system, 40-data acquisition process gas analysis work station.
Detailed description of the invention
Be described further below in conjunction with accompanying drawing 1 pair of embodiments of the invention, but the present invention is not by the restriction of embodiment:
Gas is carried out at scene, and (from the methanol-air gaseous mixture that the processes such as groove tank car or tank wagon entrucking emptying produce, gas flow is 900Nm
3/ h, gas temperature is normal temperature (environment temperature), and mist methanol concentration is 100g/m
3) be recovered after, require tail gas concentration < 50mg/m
3, utilize technical solution of the present invention to reclaim it, utilize accompanying drawing 1 to be described.
(1) methanol waste gas " absorption+absorption " recovery system comprises: blower fan 6, absorption tower 14, frequency conversion explosion proof water pump 7, adsorption tower A26, B33, vavuum pump 20, control system 39, data acquisition process and gas analysis work station 40, flowmeter 10,16, liquid level gauge 42, temperature sensor 3,9,17,22,32, control valve 4,5,11,13,15,23,24,25,27,28,34,35,36, spark arrester 1,38, ball valve 41,43, the accessories such as pressure sensor 2,8,12,19,21,31 and pipeline.
The blower fan 6 of recovery system that 1. described methanol waste gas " absorbs+absorption " is frequency conversion explosion proof blower fan, blower fan 6 is according to admission pressure size, carry out variable frequency adjustment rotation speed of fan by pressure sensor, thus control blower fan absorbing quantity, setting admission pressure is not less than-500Pa (gauge pressure).
Further, described blower fan 6 flow is: 1500Nm
3/ h.
Deployment tube groove type distributor in absorption tower 14 main body of recovery system that 2. described methanol waste gas " absorbs+absorption ", absorption tower 14 main body arranges liquid level gauge 42, temperature sensor 17 and pressure sensor 12 along absorption tower short transverse.
Further, described absorption tower height is 7m, and diameter is 0.8m.
Further, described absorption tower 14 inner absorbent is water.
Further, described coolant-temperature gage is 30 DEG C, and flow is 5t/h, and sprinkle density is 9.95m
3/ (m
2h).
Further, the liquid level of described liquid level gauge 42 controls the flow of frequency conversion explosion proof water pump, thus it is effectively moderate that guarantee is sprayed.
Further, described absorption equipment adsorption rate is 80%.
Adsorption tower A26, B33 main body of recovery system that 3. described methanol waste gas " absorbs+absorption " arranges temperature sensor 22,32 and pressure sensor 21,31 along adsorption tower A26, B33 short transverse.
Further, described adsorption tower A26, B33 are highly 5m, and diameter is 1.5m.
Further, the adsorbent loaded in described adsorption tower A26, B33 is AdsFOV-II.
The vavuum pump 20 of recovery system that 4. described methanol waste gas " absorbs+absorption " is frequency conversion explosion proof screw vacuum unit.
Further, described frequency conversion explosion proof screw vacuum unit vacuum is more than 95kPa.
The control system 39 of recovery system that 5. described methanol waste gas " absorbs+absorption " automatically controls the power-equipment of whole recovery system, to carry out gas collection, absorption and sorption and desorption operations in good time.
The data acquisition process of recovery system that 6. described methanol waste gas " absorbs+absorption " and gas analysis work station 40 be by on-line monitoring air hatch, absorption tower, in adsorption tower, the data such as the exhaust gas concentration of exhaust outlet determine absorption and sorption, desorption operations.
(2) in methanol waste gas " absorption+absorption " recovery system, each equipment connection is described below:
1. the collecting pipe that gas (the methanol-air gaseous mixture from the process such as groove tank car or tank wagon entrucking emptying produces) is carried out at scene is connected with the combi inlet port of absorption tower 14 lower body part.
2. the combi inlet port of exhaust outlet and the tail gas blow-down pipe of absorption tower 14 top cover and adsorption tower A26, adsorption tower B33 lower body part is connected.
3. the exhaust outlet of adsorption tower A26, adsorption tower B33 top cover is connected with tail gas blow-down pipe, nitrogen inlet.
4. the combi inlet port of adsorption tower A26, adsorption tower B33 lower body part is connected with vavuum pump 20 import.
5. vavuum pump 20 outlet is connected with absorption tower 14.
6. water is connected with frequency conversion explosion proof water pump 16 import, and frequency conversion explosion proof water pump 16 outlet is connected with absorption tower 14.
(3) recovery method of methanol waste gas " absorption+absorption " recovery system is:
1. scene is carried out gas (from the methanol-air gaseous mixture that the process such as groove tank car or tank wagon entrucking emptying produces, gas flow is 900Nm
3/ h, gas temperature is 35 DEG C, and mist methanol concentration is 100g/m
3mixture pressure 200kPa) utilize blower fan 6 to guide to collecting pipe, through spark arrester 1, pressure sensor 2, temperature sensor 3, control valve 5, pressure sensor 8, temperature sensor 9, flowmeter 10, enter absorption tower 14 from the combi inlet port the main body of absorption tower 14.This mist flows from bottom to top in absorption tower 14.Meanwhile, pure water by control valve 15, flowmeter 16 to top, structured packing absorption tower 14, the methanol vapor of 80% absorb by water.
2. from top, absorption tower 14 out (be generally less than 70g/m containing a small amount of methanol vapor
3) and a small amount of steam (be generally less than 51g/m
3) tail gas through pressure sensor 12, temperature sensor 17, self-priming concentration air hatch 18, control valve 27 (or 34), then the combi inlet port passed under adsorption tower A26 (or B33) main body and by adsorption tower A26 (or B33) absorption recycling.From adsorption tower A26 (or B33) top gaseous mixture out through temperature sensor 22 (or 32), pressure sensor 21 (or 31), self-priming concentration air hatch 29 (or 30), control valve 25 (or 36), spark arrester 38, enter tail gas blow-down pipe and enter air.
3. when from adsorption tower A26 (or B33) top out tail gas not meet the demands (concentration < 50mg/m at the methanol concentration that self-priming concentration air hatch 29 (or 30) gathers
3) time, the control valve 27,25 (or 34,36) connected adsorption tower A26 (or B33) main body top and the bottom by automatic control system 39 is closed, and opens the control valve 34,36 (or 27,25) that adsorption tower B33 (or A26) main body top and the bottom connect.
4. the water after absorbing methanol waste gas in absorption tower 14 is delivered to owner by frequency conversion explosion proof water pump 7 and is carried out water treatment.
5. when adsorption tower A26 (or B33) stops absorption work, open control valve 28 (or 35) that adsorption tower A26 (or B33) is connected with vavuum pump 20 by automatic control system 39, start vavuum pump 20, make the adsorbent desorb 10min after absorption methyl alcohol, when vavuum pump 20 runs last 5min, open the control valve 23 (or 24) that adsorption tower A26 (or B33) is connected with nitrogen pipeline and automatically pass into nitrogen, promote desorb.After vavuum pump 20 quits work, close the control valve 28 (or 35) that adsorption tower A26 (or B33) is connected with vavuum pump 20, continue to pass into nitrogen until adsorption tower A26 (or B33) interior pressure is normal pressure, close the control valve 23 (or 24) that adsorption tower A26 (or B33) is connected with nitrogen pipeline.