CN101798689A - Process and device for preparing nitrogen trifluoride by continuous electrolytic process - Google Patents
Process and device for preparing nitrogen trifluoride by continuous electrolytic process Download PDFInfo
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- CN101798689A CN101798689A CN 201010148219 CN201010148219A CN101798689A CN 101798689 A CN101798689 A CN 101798689A CN 201010148219 CN201010148219 CN 201010148219 CN 201010148219 A CN201010148219 A CN 201010148219A CN 101798689 A CN101798689 A CN 101798689A
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Abstract
The invention discloses process and a device for preparing nitrogen trifluoride by a continuous electrolytic process. The process comprises the following steps: using molten NH3(HF)X or adding a small amount of one or more of NaF, KF, CsF or LiF as an electrolyte system and continuously or discontinuously introducing anhydrous HF and NH3 into the electrolyte system to replenish electrolyte and adjust salt melting ratio of the system; delivering an anode crude product produced by electrolysis in an electrolytic bath (1) into a pyrolyzer (2) and removing unsaturated fluorine-nitrogen compounds such as NxFy and the like; delivering an NF3 crude product which is pyrolyzed into a bath tower (3) and removing a part of acid gases volatilizing from the electrolytic bath such as HF and the like; delivering the water-washed crude product into an alkaline washing tower (4) and further removing the acid gases, a plurality of sub-fluorides and the like; and introducing alkaline-washed gases into a water-ring vacuum pump (5) and connecting the gases in a gas holder (6). The production process is continuous, safe and stable, lowers the production cost of NF3 by collecting the gas at normal temperature and provides beneficial conditions for the purification of gas NF3 for subsequent electronic industry.
Description
Technical field
The present invention relates to nitrogen trifluoride (NF
3) preparation, particularly electrolytic process prepares the nitrogen trifluoride Processes and apparatus.
Background technology
Nitrogen trifluoride (NF
3) main etching and purge gas as unicircuit, liquid-crystal display, solar energy film and panel battery etc. in electronic industry.It also can be used as the fluorine source of high energy chemisty laser gas, the raw material of producing the perfluor ammonium salt, the blanketing gas of bulb, the oxygenant of rocket etc.
Present suitability for industrialized production NF
3Mainly contain two kinds of chemical method and fused salt electrolysis processes.Chemical method is normally used NH
3With F
2Reaction makes NF
3Crude product, refining purification obtains industrial products; Electrolytic process generally is with NH
4F-xHF is electrolyte system electrolytic preparation NF
3Thick gas is further purified and is obtained high purity product.
The major advantage of chemical method is to have avoided hydrogen (H in the production process
2) and the mixing of nitrogen trifluoride and the explosion hazard that causes.But the raw material fluorine gas (F that this method must be used
2) middle tetrafluoro-methane (CF
4) impurity is difficult removes, and easily sneaks into to be difficult in the product separate, and is used to prepare highly purified NF
3Relatively more difficult during gas.In addition, processing unit requires harsh owing to the existence of high density fluorine gas in its process system.
The advantage of electrolytic process is mainly reflected in and is easy to control CF
4Content, but in the electrolysis production process, can produce hydrogen, have to cause and NF
3The danger of gas mixed explosion.Blast not only may damage electrolyzer, and can cause NF
3CF in the gas
4The rising of content brings very big difficulty for follow-up purification.
Chinese patent ZL03122352.4 discloses processing method and the equipment that a kind of electrolytic process prepares gas of nitrogen trifluoride, as shown in Figure 2: the anode electrolysis gas in the electrolyzer enters pressure balancing tank by pipeline, the gas that comes out from pressure balancing tank enters a low pressure jar by variable valve, the gas that comes out from the low pressure jar enters the low pressure cooling tower by pipeline, removes the NH in the anode electrolysis gas
4High boiling point such as F and HF impurity has been removed the NF behind the high-boiling-point impurity through low-temp cooling tower
3Gas enters the very low temperature cold-trap by pipeline and liquefies, collects, and adopts the way that cold-trap is vacuumized to remove wherein lower boiling impurity such as N
2, O
2, the NF of in the very low temperature cold-trap, collect, liquefaction is enough
3Behind the gas, the very low temperature cold-trap is heated up, NF
3The gas distillation is pressed in the crude product gas tank, and the material of anode electrolytic cell is a high-purity nickel.Obviously, very low temperature cold-trap equipment cooling and temperature-rise period hocket in this technology, and during intensification, the gas in the electrolyzer can not enter very low temperature cold-trap equipment, the real serialization that is unrealized of whole flow process; In addition, this production technique relies on the cryotrap liquefied gas to produce pressure reduction system dynamic is provided, because of cryotrap needs to come controlled temperature and liquefaction of gases speed by the control liquid nitrogen flow, compare with the gas at normal temperature collection, integrated artistic continuity of operation and less stable, turndown ratio is less, pressure is wayward, have potential safety hazard, and the liquid nitrogen waste is bigger, causes production cost to increase.
Summary of the invention
The technical problem to be solved in the present invention is to overcome the prior art deficiency, and a kind of technology of preparing nitrogen trifluoride by continuous electrolytic process is provided.This technology is continuous, stable, collects electrolytic NF under normal temperature, condition of normal pressure
3Gas is for follow-up purifying technique creates favorable conditions.
Another technical problem that the present invention will solve provides a kind of equipment of this preparing nitrogen trifluoride by continuous electrolytic process.
Technical scheme of the present invention is: adopt electrolytic process to prepare gas of nitrogen trifluoride, with fused NH
3(HF)
XOr to add among small amount of N aF, KF, CsF or the LiF one or more be electrolyte system, continuously or feed anhydrous HF and NH intermittence
3To replenish electrolytic solution and to regulate its fused salt ratio; The anode crude product that electrolytic tank electrolysis produces enters pyrolyzer, removes N
xF
yEtc. unsaturated fluorine nitrogen compound; Through pyrolytic NF
3Crude product enters water wash column, removes the sour gas such as HF that a part evaporates from electrolyzer; Crude product after the washing enters soda-wash tower, further removes sour gas and some subfluoride etc.; Gas makes collection and confinement of gases in gas holder by water-ring vacuum pump after the alkali cleaning.
For reducing the explosion hazard in the electrolytic process and preventing that the material passing tube line from stopping up, and feeds NH
3Can be with nitrogen with its concentration dilution to 10%～95% (V/V), preferred 30%～90% (V/V).
Electrolytical fused salt is than (M in the electrolyzer
HF/ M
NH3) be generally 1.5～3.0, preferred 2.0～2.6.Electric tank working pressure-0.01～0.01MPa is advisable, and is preferred-0.005～0.005MPa; 90～150 ℃ of electrolysis temperatures, preferred 95～135 ℃.
The working temperature of pyrolyzer is generally 150～350 ℃, preferred 200～300 ℃.The residence time of process gas is general 5～100s, preferred 10～50s.The pyrolyzer material adopts metal or alloy such as carbon steel, copper, nickel, stainless steel, Monel metal; One or more fillers in copper, nickel, the Monel can wherein be loaded by heating of electrically heated cover and accurate controlled temperature in the outside.
General 10～40 ℃ of water wash column working temperature, preferred 15～35 ℃, operating pressure-0.1～0.2MPa, preferred-0.1～0.1MPa, the residence time of crude product gas in water wash column is generally 10～50min, preferred 20～30min.
The aqueous solution of soda-wash solution available bases metal hydroxides, the aqueous solution as NaOH, KOH etc., solution quality concentration is generally 3%～40%, preferred 5%～25%, general 10～40 ℃ of soda-wash tower working temperature, preferred 15～35 ℃, operating pressure is general-0.1～0.2MPa, preferably-and 0.1～0.1MPa, the residence time of crude product gas in soda-wash tower is generally 10～60min, preferred 30～40min.HF content is generally less than 5 * 10 in the crude product gas that soda-wash tower comes out
-6(V/V).
, collect by water-ring vacuum pump by the gas behind the soda-wash tower with gas holder.General 0～the 0.4MPa of gas holder operating pressure, preferred 0.005～0.2MPa.
The gas storage that technology of the present invention makes in gas holder, through the conventional purifying process of nitrogen trifluoride, as dewater, steps such as absorption and rectifying further purify, product purity can reach 99.996%, is applied to electronic industry.
Technology of the present invention is that gas is discharged power with the water-ring vacuum pump, and gas is collected in the gas holder under normal pressure, has avoided providing system dynamic with pressure reduction in the background technology, has got rid of the potential safety hazard in producing; Gas holder and water-ring vacuum pump have guaranteed the continuity of producing; The pressure of electrolyzer is stablized control by water-ring pump, reduces because of the unstable possibility that causes that the anode and cathode air chamber is collaborated and exploded of cell pressure control; Before the technology crude product is entering the gas holder storage, remove unstable impurity and sour gas such as most of subfluoride, guaranteed the safety in atmosphere storage district through pyrolyzer, water wash column, soda-wash tower.
This explained hereafter is continuous, equipment is simple to operation, safety and stability, and the normal temperature of gas is collected and reduced NF
3The production cost of gas is follow-up used in electronic industry gas NF
3Purification favourable condition is provided.
Description of drawings
Fig. 1 is a process flow sheet of the present invention.
Fig. 2 is the background technology process flow sheet.
Embodiment
Below with reference to process flow sheet of the present invention, the present invention is described more specifically.The present invention can have a lot of concrete embodiments, is not subjected to the restriction of described embodiment herein.
Electrolyte system adopts NH in the electrolyzer 1
3(HF)
XSystem, the NaF of adding 0.05%wt, the NH of feeding anhydrous HF and nitrogen dilution to 10% (V/V)
3Replenish electrolytic solution and regulate fused salt than (M
HF/ M
NH3) be 2.9.90 ℃ of electrolyzer 1 working temperatures, each components contents is in the anode export crude product:
NH
4F+HF: about 2%, N
2+ O
2+ Ar: about 37%, CF
4: 9 * 10
-6(V/V),
NF
3: about 60%, N
XF
Y: about 0.4%, CO
2: 500 * 10
-6(V/V), N
2O:0.3%
Other: about 0.3%
The anode crude product that electrolysis produces enters pyrolyzer 2 and removes N
2F
2Etc. unsaturated fluorine nitrogen compound.The temperature of pyrolyzer 2 is controlled at 350 ℃, and gas residence time is 10s, and each component concentration of taking a sample in its back is:
NH
4F+HF: about 1.7%, N
2+ O
2+ Ar: about 38%, CF
4: 9 * 10
-6(V/V),
NF
3: about 58%, CO
2: 500 * 10
-6(V/V), N
2O:0.3%
Other: about 2% N
XF
Y: 0.3 * 10
-6(V/V)
Crude product after the pyrolysis is washed and alkali cleaning successively, and water wash column 3 temperature are 25 ℃, pressure 0.1MPa, gas residence time is 10min, and soda-wash tower 4 temperature are 28 ℃, and pressure is 0.1MPa, gas residence time is 60min, and the KOH concentration of lye is 3%, NF in soda-wash tower 4 back detected gas
3Content is 58%, HF content 1 * 10
-6(V/V), CO
2Content 30 * 10
-6(V/V).
Soda-wash tower 4 back gases use gas holder 6 to collect by water-ring vacuum pump 5.Regulate water-ring vacuum pump 5 and make electrolyzer 1 pressure-stabilisation at-0.01～0.01MPa, the pressure-controlling of gas holder 6 is at 0.01～0.2MPa.
Electrolyte system adopts NH in the electrolyzer 1
3(HF)
XSystem, the CsF of adding 0.05%wt, the NH of feeding anhydrous HF and nitrogen dilution to 90% (V/V)
3Replenish electrolytic solution and regulate fused salt than (M
HF/ M
NH3) be 1.5.150 ℃ of electrolytical electrolysis temperatures, each components contents is in the anode export crude product:
NH
4F+HF: about 4%, N
2+ O
2+ Ar: about 34%, CF
4: 9 * 10
-6(V/V),
NF
3: about 60%, N
XF
Y: about 0.4%, CO
2: 500 * 10
-6(V/V), N
2O:0.8%
Other: about 0.8%
The anode crude product that electrolysis produces enters pyrolyzer 2 and removes N
2F
2Etc. unsaturated fluorine nitrogen compound.The temperature of pyrolyzer 2 is controlled at 150 ℃, gas residence time 100s, and each component concentration of taking a sample in its back is:
NH
4F+HF: about 3.5%, N
2+ O
2+ Ar: about 35%, CF
4: 9 * 10
-6(V/V),
NF
3: about 58%, CO
2: 500 * 10
-6(V/V), N
2O:0.8%
Other: about 2.7% N
XF
Y: 3 * 10
-6(V/V)
Crude product after the pyrolysis is washed and alkali cleaning successively, 25 ℃ of water wash column 3 temperature, pressure 0.1MPa, gas residence time 50min, 28 ℃ of soda-wash tower 4 temperature, pressure 0.1MPa, gas residence time 10min, KOH concentration of lye 40%, NF in soda-wash tower 4 back detected gas
3Content is 58%, HF content 3 * 10
-6(V/V), CO
2Content 20 * 10
-6(V/V).
Soda-wash tower 4 back gases use gas holder 6 to collect by water-ring vacuum pump 5.Regulate water-ring vacuum pump 5 and make electrolyzer 1 pressure-stabilisation at-0.01～0.01MPa, the pressure-controlling of gas holder 6 is at 0.01～0.2MPa.
Claims (5)
1. preparing nitrogen trifluoride by continuous electrolytic process technology is with fused NH
3(HF)
xOr to add among small amount of N aF, KF, CsF or the LiF one or more be electrolyte system, continuously or feed anhydrous HF and NH intermittence
3To replenish electrolytic solution and to regulate its fused salt ratio; The anode crude product that electrolytic tank electrolysis produces enters pyrolyzer, removes N
xF
yEtc. unsaturated fluorine nitrogen compound; Through pyrolytic NF
3Crude product enters water wash column, removes the sour gas such as HF that a part evaporates from electrolyzer; Thick product gas after the washing enters soda-wash tower, further removes sour gas and some subfluoride etc.; Gas makes collection and confinement of gases in gas holder by water-ring vacuum pump after the alkali cleaning.
2. preparation technology according to claim 1, its feature be in the electrolyzer electrolytical fused salt than (M
HF/ M
NH3) be 1.5～3.0; Electric tank working pressure-0.01～0.01MPa, 90～150 ℃ of electrolysis temperatures; The working temperature of pyrolyzer is 150～350 ℃, and the residence time of process gas is 5～100s; 10～40 ℃ of water wash column working temperatures, operating pressure-0.1～0.2MPa, the residence time of gas in water wash column is 10～50min; Soda-wash solution is the aqueous solution of alkali metal hydroxide, and strength of solution is 3%～40%, 10～40 ℃ of soda-wash tower working temperatures, operating pressure-0.1～0.2MPa; The residence time of crude product gas in soda-wash tower is 10～60min; Gas holder operating pressure 0～0.4MPa.
3. preparation technology according to claim 2, its feature be in the electrolyzer electrolytical fused salt than (M
HF/ M
NH3) be 2.0～2.6; Electric tank working pressure-0.005～0.005MPa; 95～135 ℃ of electrolysis temperatures; 200～300 ℃ of the working temperatures of pyrolyzer, the residence time of process gas is 10～50s; The pyrolyzer material adopts carbon steel, copper, nickel, stainless steel or Monel metal, and is outside by heating of electrically heated cover and controlled temperature, wherein loads one or more fillers in copper, nickel, the Monel; 15～35 ℃ of water wash column working temperatures, operating pressure-0.1～0.1MPa, the residence time of gas in water wash column is 20～30min; Soda-wash solution is the aqueous solution of NaOH or KOH, and strength of solution is 5%～25%, 15～35 ℃ of soda-wash tower working temperatures, operating pressure-0.1～0.1MPa; The residence time of crude product gas in soda-wash tower is 30～40min; The gas holder operating pressure is 0.005～0.2MPa.
4. according to the described preparation technology of one of claim 1～3, it is characterized in that the NH that feeds
3With nitrogen with its concentration dilution to 10%～95% (V/V).
5. the equipment of the described preparing nitrogen trifluoride by continuous electrolytic process technology of claim 1 comprises electrolyzer, pyrolyzer, water wash column, and soda-wash tower, water-ring vacuum pump, gas holder connect successively by pipeline between each equipment; The pyrolyzer material adopts carbon steel, copper, nickel, stainless steel or Monel metal, wherein loads one or more fillers in copper, nickel, the Monel.
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|---|---|---|---|
| CN 201010148219 CN101798689A (en) | 2010-03-18 | 2010-03-18 | Process and device for preparing nitrogen trifluoride by continuous electrolytic process |
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|---|---|---|---|
| CN 201010148219 CN101798689A (en) | 2010-03-18 | 2010-03-18 | Process and device for preparing nitrogen trifluoride by continuous electrolytic process |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101913578A (en) * | 2010-08-30 | 2010-12-15 | 天津市泰源工业气体有限公司 | Technology for preparing high-purity nitrogen trifluoride by removing impurities from nitrogen trifluoride by adsorptive method |
| CN102605384A (en) * | 2011-01-18 | 2012-07-25 | 气体产品与化学公司 | Electrolytic apparatus, system and method for the safe production of nitrogen trifluoride |
| CN104947135A (en) * | 2015-06-09 | 2015-09-30 | 中国船舶重工集团公司第七一八研究所 | Device for preparing nitrogen trifluoride and application |
| CN110234992A (en) * | 2017-07-31 | 2019-09-13 | 株式会社Lg化学 | Device for the oxygen generated in quantitative analysis battery material |
| CN112742158A (en) * | 2020-12-30 | 2021-05-04 | 中船重工（邯郸）派瑞特种气体有限公司 | Hydrogen fluoride waste gas treatment system and method in nitrogen trifluoride electrolysis preparation process |
| CN113247870A (en) * | 2021-04-03 | 2021-08-13 | 中船重工（邯郸）派瑞特种气体有限公司 | Method and device for preparing high-purity nitrogen trifluoride gas |
| CN115490215A (en) * | 2022-09-20 | 2022-12-20 | 洛阳森蓝化工材料科技有限公司 | Device and method for preparing nitrogen trifluoride |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101913578A (en) * | 2010-08-30 | 2010-12-15 | 天津市泰源工业气体有限公司 | Technology for preparing high-purity nitrogen trifluoride by removing impurities from nitrogen trifluoride by adsorptive method |
| CN102605384A (en) * | 2011-01-18 | 2012-07-25 | 气体产品与化学公司 | Electrolytic apparatus, system and method for the safe production of nitrogen trifluoride |
| US8945367B2 (en) | 2011-01-18 | 2015-02-03 | Air Products And Chemicals, Inc. | Electrolytic apparatus, system and method for the safe production of nitrogen trifluoride |
| CN102605384B (en) * | 2011-01-18 | 2016-05-11 | 气体产品与化学公司 | For electrolysis installation, the system and method for the Nitrogen trifluoride of keeping the safety in production |
| CN104947135A (en) * | 2015-06-09 | 2015-09-30 | 中国船舶重工集团公司第七一八研究所 | Device for preparing nitrogen trifluoride and application |
| CN110234992A (en) * | 2017-07-31 | 2019-09-13 | 株式会社Lg化学 | Device for the oxygen generated in quantitative analysis battery material |
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| CN112742158A (en) * | 2020-12-30 | 2021-05-04 | 中船重工（邯郸）派瑞特种气体有限公司 | Hydrogen fluoride waste gas treatment system and method in nitrogen trifluoride electrolysis preparation process |
| CN113247870A (en) * | 2021-04-03 | 2021-08-13 | 中船重工（邯郸）派瑞特种气体有限公司 | Method and device for preparing high-purity nitrogen trifluoride gas |
| CN115490215A (en) * | 2022-09-20 | 2022-12-20 | 洛阳森蓝化工材料科技有限公司 | Device and method for preparing nitrogen trifluoride |
| CN115490215B (en) * | 2022-09-20 | 2024-01-30 | 洛阳森蓝化工材料科技有限公司 | Device and method for preparing nitrogen trifluoride |
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Open date: 20100811 |