The high pure nitrogen body is widely used in the production process of petrochemical complex, chemical industry, electronic industry, metallurgical industry and building materials industry as the shielding gas in producing.The preparation of high purity nitrogen in the past adopts the empty method of dividing of deep cooling to produce usually, but huge for the investment of deep cooling air separation plant, and the energy consumption height only is suitable for the production (>10000M of large-scale high purity nitrogen
3/ hr), the purity nitrogen production of centering, hour scale is non-remunerative economically.
The carbonaceous molecular sieve making nitrogen by pressure swing adsorption is the seventies new developing technology, compares with molten cold nitrogen production by air separation method, and this technology is simple with its equipment, less investment, simple to operate, low power consumption and other advantages, the nitrogen production of centering, hour scale is more reasonable economically, is popular in users.Unique shortcoming of making nitrogen by pressure swing adsorption is that nitrogen gas purity is not too high, generally at 99.5% (0.5%O
2), in most cases, need further to purify, can be used for production process.At present, thick nitrogen deoxidation is mainly catforming, promptly adds excessive 0.2~5.0% hydrogen in smart nitrogen, under the effect of catalyzer such as palladium/aluminum oxide, residual oxygen in the nitrogen is removed.With the purifying method of above-mentioned catalyst removal oxygen, the oxygen level of its finished product gas is 0.2~10ppm, and the hydrogen residual volume surpasses 0.2% in the nitrogen, is high purity nitrogen so be far from being, and can only be used for the industry that thermal treatment etc. needs hydrogen.
Thick nitrogen purifies the general oxide compound absorption process of appraising at the current rate that adopts of the another kind of method that removes oxygen, and carbon burning consumes method.Absorption process reductor commonly used has manganese oxide (MnOx), silver suboxide (Ag
2O), cupric oxide (CuOx) (referring to Wu Yanmin " purification for gas " 23,1983, National Defense Industry Press).5~15 milliliters of the former general every gram reductor deoxidations, because thick nitrogen oxygen level height, so need a large amount of reductors, treating plant is huge, and is more uneconomical economically.Though latter's deoxidation is great, belongs to expendable, and 320~900 ℃ of uses, and produce new impurity CO and CO
2Up to now, the purification that contains the thick nitrogen of hyperoxia amount is the difficult problem in the gas sweetening, and Shang Weiyou rational technology is economically solved.
The purpose of this invention is to provide a kind of economy, be suitable for extensive use, is method for gas purification and the technical process that unstripped gas is produced high purity nitrogen with thick nitrogen.
Adopt in the present invention the applicant's early development contain precious metals pd and/or Pt dehydrogenation catalyst (number of patent application 96115578.7) but and not only can inhale hydrogen but also oxygen uptake contain precious metals pd/manganese oxide regulating catalyst and technical process (seeing accompanying drawing 1), dividing two sections is high purity nitrogen with thick nitrogen deep purifying.In first section cleaner, the thick excessive hydrogenation of nitrogen, under the effect that contains precious metals pd and/or Pt dehydrogenation catalyst, the hydrogen-oxygen catalyzed reaction generates water and removes deoxidation.Remaining hydrogen in the nitrogen after first section purification by second section cleaner adsorbing and removing that contains Pd/ manganese oxide regulating catalyst, obtains H
2, O
2The high pure nitrogen of<1ppm.Second section cleaner contains precious metals pd/manganese oxide purification reactor by two and forms, switch to use, i.e. and reactor hydrogen in inhaling hydrogen purification nitrogen, another reactor is then logical to contain the thick nitrogen oxidation regeneration of oxygen, hockets operate continuously.If high purity nitrogen requires the control moisture content, then need add conventional 5A molecular sieve purification process in the technical process and be dewatered.The condition of its scavenging process is: first section cleaner temperature of reaction is normal temperature~200 ℃, air speed 4000~8000hr
-1, oxygen level 0.05~3.0% in the nitrogen, and than excessive 200~500ppm, method of hydrotreating adopts pure hydrogen source or ammonia cracking hydrogen source to the hydrogenation amount by the metering of oxygen level in the thick nitrogen in the thick nitrogen.The dehydrogenation working temperature of second section cleaner is 100~150 ℃, contains the regeneration of precious metals pd/manganese oxide regulating catalyst and carries out 100~250 ℃ of regeneration temperatures containing under the oxygen-nitrogen atmosphere.Purge gas pressure is 0.1~3MPa.
Below by embodiment invention is described further:
Example 1: the preparation (0.25%Pt+0.25%Pd/TiO that contains precious metals pd and/or Pt dehydrogenation catalyst
2+ Al
2O
3)
Get 100 milliliters of (0.025 gram Pd/ milliliter) aqueous solution+(the 0.025 gram Pt/ milliliter) aqueous solution 100 milliliters+60 ml waters and mix, again with 1000 gram column (TiO
2+ Al
2O
3) carrier pours in the above-mentioned solution, floods 4 hours, 80~120 ℃ of oven dry were got 100 milliliters of reduction of hydrazine hydrate of 50% 12 hours, and deionized water wash is to there not being Cl
-, pH=7 places 80~120 ℃ of baking ovens dry, places in the tube furnace under 500~750 ℃ of nitrogen atmosphere thermal treatment again 1~4 hour, is cooled to the logical nitrogen row hydrogen taking-up of chamber, chamber naturally.
Example 2: the performance of dehydrogenation catalyst
Because oxygen level is widely different in the various thick nitrogen, on φ 25mm continuous flow reaction unit, restrains and contain precious metals pd and/or the Pt dehydrogenation catalyst carries out the quantitative hydrogenation deoxidation evaluation of various oxygen concns with 80.Be equipped with metering in the nitrogen than electrolysis hydrogen, oxygen, air speed 5000br
-1, temperature of reaction is a normal temperature, follows the tracks of with the Nanjing GH-3 of analytical instrument factory type oxygen analyzer and detects, the results are shown in Table 1 for it.
Table 1 contains precious metals pd and/or the quantitative hydrogenation deoxidation performance of the smart nitrogen of Pt dehydrogenation catalyst
| Oxygen level (ppm) | Hydrogenation amount (ppm) | Use temperature (℃) | Residual hydrogen amount (ppm) |
| 2000 | 4000 | 25 | <0.3 |
| 5000 | 10000 | 25 | <0.3 |
| 30000 | 60000 | 25 | <0.3 |
As can be seen from Table 1, during different oxygen, hydrogen, oxygen level are for measuring than under the condition, and this catalyzer also has the very high effect that removes oxygen.
Example 3: nitrogen advanced purification process method
Accompanying drawing 1 is the process flow sheet that thick nitrogen is produced high purity nitrogen, with the refining plant of this process design is that the first section cleaner that contains 18 kilograms of precious metals pd and/or Pt dehydrogenation catalysts is housed, with the second section cleaner that contains 37.5 kilograms of precious metals pd/manganese oxide regulating catalysts (Dalian Inst of Chemicophysics, Chinese Academy of Sciences produces 506HO type commercial catalyst), thick nitrogen (making nitrogen by pressure swing adsorption) flow is 60M
3/ hr.Carry out the commerical test of smart nitrogen hydrogenation deoxidation with this device, the results are shown in Table 2 for it.The working temperature of first section cleaner is a normal temperature, and pressure 0.5MPa uses air speed 4000hr
-1, detecting instrument is the Nanjing DH-3 of an analytical instrument factory type oxygen analyzer.
Table 2 contains precious metals pd and/or Pt dehydrogenation catalyst industry use properties
| Nitrogen source | Oxygen level (ppm) | Hydrogenation amount (ppm) | Residual hydrogen amount (ppm) |
| Making nitrogen by pressure swing adsorption | 0.5 | 10.2~1.05 | <1 |
As can be seen from Table 2, contain precious metals pd and/or Pt dehydrogenation catalyst under the big air speed working conditions of industry, effect is still fine.
On said apparatus, nitrogen after the deoxidation carries out hydrogen with the 506HO regulating catalyst and absorbs, the working temperature of second section cleaner is 100~150 ℃, pressure 0.6MPa, hydrogen before and after absorbing is followed the tracks of detection with the OHW-01 type and the CD-HY type hydrogen detector of Dalian Inst of Chemicophysics, Chinese Academy of Sciences's system, and the results are shown in Table 3 for it.
Table 3 506HO regulating catalyst dehydrogenation
| Hydrogen richness (ppm) | Use temperature (℃) | Applying pressure (MPa) | Residual hydrogen amount (ppm) |
| 200~500 | 100~150 | 0.6 | <1 |
As can be seen from Table 3, after the 506HO regulating catalyst was inhaled hydrogen, hydrogen was residual heavy less than 1ppm, and transformation is adsorbed thick nitrogen after above second cleaner purifies, and hydrogen, oxygen all become high purity nitrogen less than 1ppm.
The continuous flow reaction unit is adopted in above-mentioned technical process, catalyzer successive reaction and regeneration, its process stream trend is: the transformation adsorption of nitrogen through valve, under meter to mixing tank; Hydrogen or ammonia cracking hydrogen mix with nitrogen to mixing tank through valve, under meter, and mixed gas enters first section cleaner 17, under the effect that contains precious metals pd and/or Pt dehydrogenation catalyst, and the normal temperature deoxidation.Nitrogen after the deoxidation enters second section cleaner, one of them 506HO reactor 18, and under the effect of 506HO regulating catalyst, the absorbing and removing excessive hydrogen.Nitrogen after the dehydrogenation enters next stage and carries out conventional 5A molecular sieve dehydration, thereby obtains high purity nitrogen.In one second section reactor 18 dehydrogenations, to another second section 506HO reactor 19,, after having regenerated, replace with high purity nitrogen with the oxygenous oxidation regeneration that carries out of transformation absorption, use in order to switching.
It is 60M that the thick nitrogen of above-mentioned reaction unit carries out tolerance
3/ hr
-1, pressure 0.6MPa, first section cleaner working temperature is normal temperature~200 ℃, the 506HO regulating catalyst inhales hydrogen and regeneration temperature is 100~250 ℃, O in the high purity nitrogen
2, H
2<1ppm.