CN116440890B - Preparation method of high-activity renewable active carbon for phosgene synthesis and online regeneration process thereof - Google Patents
Preparation method of high-activity renewable active carbon for phosgene synthesis and online regeneration process thereof Download PDFInfo
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- CN116440890B CN116440890B CN202210020265.2A CN202210020265A CN116440890B CN 116440890 B CN116440890 B CN 116440890B CN 202210020265 A CN202210020265 A CN 202210020265A CN 116440890 B CN116440890 B CN 116440890B
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 468
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 title claims abstract description 194
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 120
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 110
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 70
- 230000000694 effects Effects 0.000 title claims abstract description 31
- 230000008569 process Effects 0.000 title claims abstract description 31
- 230000008929 regeneration Effects 0.000 title claims abstract description 30
- 238000011069 regeneration method Methods 0.000 title claims abstract description 30
- 238000002360 preparation method Methods 0.000 title abstract description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 100
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 48
- 239000002994 raw material Substances 0.000 claims abstract description 18
- 230000002194 synthesizing effect Effects 0.000 claims abstract description 14
- -1 nitrogenous aromatic ring compound Chemical class 0.000 claims abstract description 12
- 238000005406 washing Methods 0.000 claims abstract description 11
- 239000002253 acid Substances 0.000 claims abstract description 10
- 238000002156 mixing Methods 0.000 claims abstract description 9
- 238000004140 cleaning Methods 0.000 claims abstract description 8
- 229910021645 metal ion Inorganic materials 0.000 claims abstract description 8
- 238000012544 monitoring process Methods 0.000 claims abstract description 4
- 230000001172 regenerating effect Effects 0.000 claims abstract description 3
- 239000000460 chlorine Substances 0.000 claims description 103
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 101
- 229910052801 chlorine Inorganic materials 0.000 claims description 96
- 239000003054 catalyst Substances 0.000 claims description 60
- 239000000843 powder Substances 0.000 claims description 44
- 239000007789 gas Substances 0.000 claims description 35
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 34
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 34
- 238000006243 chemical reaction Methods 0.000 claims description 26
- 238000003795 desorption Methods 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 16
- 238000001035 drying Methods 0.000 claims description 13
- 238000001179 sorption measurement Methods 0.000 claims description 13
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims description 12
- 230000009471 action Effects 0.000 claims description 10
- 239000008367 deionised water Substances 0.000 claims description 10
- 229910021641 deionized water Inorganic materials 0.000 claims description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 9
- 238000011156 evaluation Methods 0.000 claims description 9
- 239000012535 impurity Substances 0.000 claims description 8
- 238000001723 curing Methods 0.000 claims description 7
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 7
- 238000003860 storage Methods 0.000 claims description 7
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 5
- BHXFKXOIODIUJO-UHFFFAOYSA-N benzene-1,4-dicarbonitrile Chemical compound N#CC1=CC=C(C#N)C=C1 BHXFKXOIODIUJO-UHFFFAOYSA-N 0.000 claims description 5
- NHYCGSASNAIGLD-UHFFFAOYSA-N chlorine monoxide Inorganic materials Cl[O] NHYCGSASNAIGLD-UHFFFAOYSA-N 0.000 claims description 5
- 229910052740 iodine Inorganic materials 0.000 claims description 5
- 239000011630 iodine Substances 0.000 claims description 5
- 229910017604 nitric acid Inorganic materials 0.000 claims description 5
- 239000011230 binding agent Substances 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 4
- HCVANKFEUQUUGJ-UHFFFAOYSA-N C(=O)(Cl)Cl.[C] Chemical compound C(=O)(Cl)Cl.[C] HCVANKFEUQUUGJ-UHFFFAOYSA-N 0.000 claims description 2
- 235000013162 Cocos nucifera Nutrition 0.000 claims description 2
- 244000060011 Cocos nucifera Species 0.000 claims description 2
- 239000003245 coal Substances 0.000 claims description 2
- 230000017525 heat dissipation Effects 0.000 claims description 2
- 238000004898 kneading Methods 0.000 claims description 2
- AZKDTTQQTKDXLH-UHFFFAOYSA-N naphthalene-2-carbonitrile Chemical compound C1=CC=CC2=CC(C#N)=CC=C21 AZKDTTQQTKDXLH-UHFFFAOYSA-N 0.000 claims description 2
- 230000035484 reaction time Effects 0.000 claims description 2
- 238000004064 recycling Methods 0.000 claims description 2
- 229910001873 dinitrogen Inorganic materials 0.000 claims 4
- 150000001804 chlorine Chemical class 0.000 claims 2
- 229920006395 saturated elastomer Polymers 0.000 claims 1
- 238000007036 catalytic synthesis reaction Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 21
- 239000004372 Polyvinyl alcohol Substances 0.000 description 13
- 229920002451 polyvinyl alcohol Polymers 0.000 description 13
- 230000003197 catalytic effect Effects 0.000 description 11
- 238000002371 ultraviolet--visible spectrum Methods 0.000 description 8
- 238000007664 blowing Methods 0.000 description 7
- 239000012948 isocyanate Substances 0.000 description 7
- 150000002513 isocyanates Chemical class 0.000 description 7
- 239000011812 mixed powder Substances 0.000 description 7
- ZRGWPBMLHDBMNH-UHFFFAOYSA-N pentanedial;hydrochloride Chemical compound Cl.O=CCCCC=O ZRGWPBMLHDBMNH-UHFFFAOYSA-N 0.000 description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 description 6
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 6
- 238000005485 electric heating Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000012546 transfer Methods 0.000 description 6
- 239000000853 adhesive Substances 0.000 description 5
- 230000001070 adhesive effect Effects 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 229920002545 silicone oil Polymers 0.000 description 5
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 4
- 239000012300 argon atmosphere Substances 0.000 description 4
- 239000012267 brine Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 239000002826 coolant Substances 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 238000010926 purge Methods 0.000 description 4
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical group O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000012459 cleaning agent Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010924 continuous production Methods 0.000 description 3
- 238000011049 filling Methods 0.000 description 3
- 239000002480 mineral oil Substances 0.000 description 3
- 235000010446 mineral oil Nutrition 0.000 description 3
- 238000005554 pickling Methods 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 238000010992 reflux Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 239000012086 standard solution Substances 0.000 description 3
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 239000012295 chemical reaction liquid Substances 0.000 description 2
- MVPPADPHJFYWMZ-IDEBNGHGSA-N chlorobenzene Chemical group Cl[13C]1=[13CH][13CH]=[13CH][13CH]=[13CH]1 MVPPADPHJFYWMZ-IDEBNGHGSA-N 0.000 description 2
- 230000009849 deactivation Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000006552 photochemical reaction Methods 0.000 description 2
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000007873 sieving Methods 0.000 description 2
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 2
- UPMLOUAZCHDJJD-UHFFFAOYSA-N 4,4'-Diphenylmethane Diisocyanate Chemical compound C1=CC(N=C=O)=CC=C1CC1=CC=C(N=C=O)C=C1 UPMLOUAZCHDJJD-UHFFFAOYSA-N 0.000 description 1
- 101001018064 Homo sapiens Lysosomal-trafficking regulator Proteins 0.000 description 1
- 102100033472 Lysosomal-trafficking regulator Human genes 0.000 description 1
- 235000010703 Modiola caroliniana Nutrition 0.000 description 1
- 244000038561 Modiola caroliniana Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- VEFXTGTZJOWDOF-UHFFFAOYSA-N benzene;hydrate Chemical compound O.C1=CC=CC=C1 VEFXTGTZJOWDOF-UHFFFAOYSA-N 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- ZZTCPWRAHWXWCH-UHFFFAOYSA-N diphenylmethanediamine Chemical compound C=1C=CC=CC=1C(N)(N)C1=CC=CC=C1 ZZTCPWRAHWXWCH-UHFFFAOYSA-N 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 239000012442 inert solvent Substances 0.000 description 1
- 239000000543 intermediate Substances 0.000 description 1
- NIMLQBUJDJZYEJ-UHFFFAOYSA-N isophorone diisocyanate Chemical compound CC1(C)CC(N=C=O)CC(C)(CN=C=O)C1 NIMLQBUJDJZYEJ-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 229920000768 polyamine Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920006389 polyphenyl polymer Polymers 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/18—Carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/20—Regeneration or reactivation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/02—Heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J38/00—Regeneration or reactivation of catalysts, in general
- B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/80—Phosgene
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Inorganic Chemistry (AREA)
- Catalysts (AREA)
Abstract
The invention relates to a preparation method of high-activity renewable active carbon suitable for phosgene synthesis and an online regeneration process thereof, which comprises the following steps: 1. taking a nitrogenous aromatic ring compound as a raw material, carrying out catalytic synthesis reaction at high temperature, and cleaning to obtain carbon powder, mixing the carbon powder with common activated carbon powder to obtain a raw material, and carrying out acid washing to remove metal ions to prepare the high-activity activated carbon suitable for phosgene synthesis; 2. the active carbon regenerating process includes electric heater, temperature monitoring inside the synthesizing tower, heat transferring system design, and on-line regeneration of active carbon with high temperature CO and high temperature nitrogen.
Description
Technical Field
The invention relates to a preparation method of high-activity renewable active carbon suitable for phosgene synthesis and an online regeneration process thereof.
Background
Phosgene is mainly applied to the fields of organic synthesis, pesticides, medicines, dyes, intermediates of other chemical products and the like. Continuous production of phosgene by carbon monoxide and chlorine catalyzed synthesis in a shell-and-tube reactor using activated carbon as a catalyst is well known in the art.
CN1765740a discloses a phosgene production method and apparatus in which chlorine and carbon monoxide are reacted in the presence of an activated carbon catalyst in a shell-and-tube reactor comprising a plurality of reaction tubes and a coolant space surrounding the reaction tubes, wherein a) the reaction tubes are cooled from the outside by the coolant space cooled by water evaporation, b) the pressure of the reaction tubes is greater than the pressure in the coolant space when operated.
CN102092713a discloses a process for producing phosgene from chlorine and carbon monoxide by reacting them in the presence of an activated carbon catalyst, in particular to a process for producing phosgene by exothermic reaction of chlorine and carbon monoxide in a shell-and-tube reactor. Wherein, chlorine and excessive carbon monoxide are mixed in a mixer M1 and then enter a tubular reactor to react under the action of an active carbon catalyst to generate phosgene, and the phosgene is protected by a reactor to ensure that the chlorine is completely reacted; the heat generated by the reaction is led out by a cooling water system with the temperature of 60 ℃ in a closed cycle, the generated gaseous phosgene is condensed and cooled in two stages and then enters a phosgene gas-liquid separation tank, the uncondensed gas enters a tail gas absorption tower, and the toluene with the temperature of minus 5 ℃ is used for absorbing the phosgene contained in the tail gas and recycling the phosgene.
Along with the continuous extension of the service time of the active carbon of the phosgene synthesis catalyst, the capability of the active carbon for catalyzing the phosgene synthesis slowly decreases, so that the content of free chlorine in the synthesized phosgene at the outlet is continuously increased.
The reaction of phosgene and an amine may be carried out to synthesize isocyanates such as Toluene Diisocyanate (TDI), 4' -diphenylmethane diisocyanate (MDI), hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), and the like. At present, isocyanate is mainly prepared by adopting a phosgene method, corresponding amines such as diphenyl methane diamine and polymethylene polyphenyl polyamine are mixed with inert solvents and then fully mixed with phosgene for phosgenation reaction, so as to obtain photochemical reaction liquid, and the photochemical reaction liquid is subjected to phosgene removal and solvent removal to obtain an isocyanate crude product. Chlorine in phosgene can lead to reaction to produce a large amount of chlorinated byproducts and acids, so that the crude isocyanate product contains a large amount of acid components and hydrolyzes chlorine, and the appearance color of the crude isocyanate product is influenced. It is therefore necessary to ensure a low free chlorine content in the raw phosgene for isocyanate production.
In the common isocyanate manufacturing technology, when the catalytic activity of the catalyst active carbon in the phosgene synthesis tower is obviously reduced, the catalyst active carbon in the phosgene synthesis tower needs to be replaced by stopping to ensure that free chlorine contained in phosgene has adverse effect on products. Because of the dangerous materials such as residual phosgene, chlorine and the like in the activated carbon, the toxic and harmful dangerous materials are required to be removed, and the operation such as equipment opening, catalyst replacement and the like can be performed on the synthesis tower.
CN105817183a discloses a method for quickly removing phosgene in a catalyst when the catalyst of a phosgene synthesis tower is replaced. The method comprises the steps of blowing out the phosgene which is adsorbed in the active carbon of the catalyst of the phosgene synthesis tower and is easy to desorb by blowing out nitrogen, and then blowing out ammonia, wherein the ammonia reacts with the phosgene which is difficult to desorb in the catalyst of the phosgene synthesis tower to remove. The content of phosgene at the outlet of the phosgene synthesis tower after purging is lower than 0.5ppm, so that the time for purging the phosgene of the phosgene synthesis tower can be obviously reduced, the nitrogen consumption is greatly reduced, and the safety of process operation is improved.
In the above documents and other prior arts, it is described that the removal treatment of residual phosgene in the catalyst of the phosgene synthesis tower is performed by using purge gas such as hot nitrogen, ammonia, etc., so that the time for purging phosgene in the phosgene synthesis tower is significantly reduced, but since the activated carbon has a certain adsorption capacity, part of phosgene and chlorine can be adsorbed, and a certain risk still exists in the process of disassembling the activated carbon. Meanwhile, the synthetic tower is purged, the activated carbon is disassembled, the activated carbon filling still needs about 15-30 days, the operation time is long, the continuous production of phosgene is influenced, and the production operation load of a downstream phosgene using device of an industrial chain is further influenced.
Therefore, a more convenient and safer technical scheme is needed to reduce the influence on the continuous synthesis production of the light gas caused by the reduction of the catalytic activity of the activated carbon.
Disclosure of Invention
The inventor carries out analysis and research on fresh active carbon and active carbon synthesized by phosgene for 1-2 years, and discovers that the iodine adsorption value of the active carbon with reduced activity or inactive activity is obviously reduced from 800-1200mg/g to 500-700mg/g; the total carbon content of the activated carbon is obviously reduced from 85-95% to 40-60%, and correspondingly, the volatile content of the activated carbon is increased from 0-5% to 15-45%. It is presumed that in the phosgene synthesis process, chlorine element forms a strong bonding state with activated carbon, occupies part of the catalytic active sites, and causes a decrease in the catalytic activity of the activated carbon. Therefore, the preparation method of the high-activity active carbon can be developed to improve the phosgene synthesis reaction activity of the active carbon and prolong the service life of the active carbon, and meanwhile, a technology is developed to monitor the activity of the active carbon in the phosgene synthesis process on line and remove chlorine-containing impurities in the deactivated active carbon on line, recover the phosgene catalytic activity of the active carbon and reduce the influence of the deactivation of the active carbon on the continuous production of phosgene.
The inventor also found that after the conventional commercial activated carbon is industrially used for 1-2 years in the catalytic phosgene synthesis reaction, the total volume of the activated carbon is lost by about 40% -60%, so that the activated carbon is inevitably required to be supplemented by opening equipment, thereby bringing the risks of safety and yield loss. Therefore, the loss of the activated carbon in the using process is reduced, so that more than 85% of the volume of the activated carbon after the use is the precondition for the regeneration of the activated carbon.
The invention aims at providing a preparation method of high-activity active carbon suitable for phosgene synthesis, which takes a nitrogenous aromatic ring compound as a raw material, and the method comprises the steps of polymerization reaction, acid washing, extrusion molding, curing, drying and roasting to obtain the high-activity renewable active carbon, wherein the service life of the active carbon can be prolonged by more than 50%, and the loss of the active carbon after 1-2 years of use is less than 15% (volume ratio).
The nitrogen-containing aromatic ring compound can form a reticular polymer with stable structure under the action of a catalyst, and the nitrogen-doped activated carbon powder can be obtained after high-temperature treatment. When the nitrogen in the raw material is of a pyridine type, the pyridine type nitrogen can be introduced into the activated carbon, and the nitrogen has very strong electron withdrawing property, so that the positive charge density on adjacent carbon atoms is remarkably improved, cl 2 adsorbed on the surface of the activated carbon in the phosgene synthesis reaction is more easily activated to form Cl free radicals, the phosgene synthesis reaction rate is further accelerated, and the reactivity of the activated carbon is improved.
Through analysis and comparison of metal content in different activated carbon and service life of the activated carbon, the active carbon has remarkable effect of catalyzing chlorine and carbon to react to generate micromolecular chlorinated alkane, so that the skeleton structure of the activated carbon is damaged, further carbon loss is caused, and remarkable volume loss of the activated carbon is caused. Therefore, the acid washing process is one of the important means for prolonging the service life of the active carbon and reducing the loss of the active carbon in the phosgene synthesis process.
The invention also provides an online regeneration process of the phosgene synthesis active carbon, which adopts high-temperature carbon monoxide and high-temperature nitrogen to carry out heat treatment on the deactivated active carbon, can remove more than 80% of chlorine-containing impurities in the deactivated active carbon, recover the iodine adsorption value and the total carbon content of the active carbon to the level of 80-90% of fresh active carbon, recover the activity of the active carbon catalytic phosgene synthesis, effectively reduce the time of stopping a phosgene production device caused by the reduction of the activity of the active carbon, prolong the period of stable operation of the device and avoid the safety risk caused by the disassembly of the active carbon containing phosgene.
In order to achieve the above purpose, the invention adopts the following technical scheme:
The invention provides a preparation method of high-activity renewable active carbon suitable for phosgene synthesis, which comprises the following steps:
1) Under the protection of inert gas, the nitrogen-containing aromatic ring compound reacts for a certain time at a high temperature by taking anhydrous ZnCl 2 as a catalyst to obtain black powder. Washing the powder to remove unreacted raw materials, mixing the powder with ordinary carbon powder according to a certain proportion, further removing metal ions by acid washing at a certain temperature, washing the powder, and drying to obtain raw material carbon powder;
2) The carbon powder and the binder are uniformly mixed and kneaded into a plastic blank, extruded to form strips, cured, dried and roasted to obtain the active carbon suitable for phosgene synthesis.
In the preparation method, in the step 1), the adopted nitrogen-containing aromatic ring compound is one or more of 1, 4-dicyanobenzene, 2, 6-naphthalonitrile and 1,3, 5-3-cyanobenzene, the molar ratio of the nitrogen-containing aromatic ring compound to anhydrous ZnCl 2 serving as a catalyst is selected from 3:1-7:1, the inert gas is nitrogen, the reaction temperature is selected from 300-500 ℃, and the reaction time is selected from 20-60h.
In the preparation method, in the step 1), the method for cleaning the unreacted raw materials in the powder is to clean the raw materials for 1 to 3 times by adopting 2 percent diluted hydrochloric acid with the mass of 10 to 30 times of the powder and then clean the raw materials for 1 to 3 times by adopting deionized water with the mass of 25 to 75 times of the powder.
In the preparation method, in the step 1), the carbon powder used for blending is commercially available coconut shell activated carbon or coal-based activated carbon powder, and the blending proportion is the carbon powder prepared from the nitrogenous aromatic ring compound in the step 1): the commercial active carbon powder is 1:1-1:4.
In the preparation method, in the step 1), the method for removing metal ions in the powder by acid washing is that the powder is heated and refluxed in 10% nitric acid solution at 90-100 ℃ for 1-4h, deionized water with the mass 25-75 times of that of the powder is adopted for 1-3 times, and then the powder is dried to constant weight in nitrogen atmosphere at 100-150 ℃.
The preparation method, step 2) can refer to the preparation method of the activated carbon provided in patent CN110449147 claims 8 and 9. The adhesive is hydrochloric acid solution of polyvinyl alcohol and glutaraldehyde, and the mass ratio of the polyvinyl alcohol to the glutaraldehyde is 10-50: 1, preferably 15 to 40:1, a step of; and/or the molecular weight of the polyvinyl alcohol is 20000 to 150000, more preferably 50000 to 120000; and/or the mass concentration of the glutaraldehyde hydrochloric acid solution is 0.5-20%, preferably 1-5%. Sequentially adding hydrochloric acid solutions of polyvinyl alcohol and glutaraldehyde into the mixed powder, wherein the mass ratio of the adhesive solution to the carbon powder is 5:1-15:1; kneading and extruding to form strips of 1-5 mm diameter and 1-10 mm length. The curing is carried out at room temperature, preferably 20-30 ℃; curing time is 1-5 h, preferably 2-4 h; and/or, the drying is carried out at a drying temperature of 80-150 ℃, preferably 100-130 ℃; drying time is 1-24 h, preferably 2-18 h; and/or the roasting is carried out in an argon atmosphere, wherein the roasting temperature is 700-1000 ℃, preferably 750-900 ℃; the calcination time is 1 to 5 hours, preferably 2 to 5 hours.
The invention also provides a method for synthesizing phosgene and regenerating an active carbon catalyst on line, which comprises the following steps:
1) Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tube type fixed bed reactor, a catalyst is filled in a tube, a multipoint thermometer is arranged in a part of the tube, and a high-temperature resistant heat conducting medium is adopted outside the tube for absorbing reaction heat generated by synthesizing phosgene; the catalyst is the high-activity active carbon;
2) When the highest temperature point in the active carbon bed layer in the phosgene synthesis tower moves to a certain position, the active carbon phosgene synthesis activity is reduced, the content of residual chlorine in synthesized phosgene is increased, and the active carbon in the phosgene synthesis tower is converted into deactivated active carbon; at the moment, the active carbon is regenerated on line, the light gas synthesizing tower system is pretreated, and then the deactivated active carbon is regenerated on line by adopting high-temperature carbon monoxide and high-temperature nitrogen.
In the process of phosgene synthesis and on-line regeneration of the active carbon catalyst, in the step 1), an electric heater is arranged at the inlet of a phosgene synthesis tower, and carbon monoxide or nitrogen can be heated to 300-600 ℃; the phosgene synthesis tower is two stages, the first stage is a tubular fixed bed reactor, the tubular length is selected from 2-6m, and the second stage is a bulk fixed bed reactor; the heat conducting medium outside the shell side of the first-stage phosgene synthesis tower is from a closed circulation system, a medium cooler is arranged in the system for phosgene synthesis working conditions, a heat conducting medium storage tank is arranged for storing the heat conducting medium under active carbon regeneration working conditions, and a vacuumizing system is arranged for vacuumizing the gas in the shell side space to form a negative pressure or vacuum environment; a multipoint thermometer is arranged in the first-stage phosgene synthesis tower and is used for monitoring the temperature of an activated carbon bed layer in the tube array.
In the process of phosgene synthesis and on-line regeneration of the active carbon catalyst, in the step 1), the heat conducting medium is selected from high-temperature resistant silicone oil, high-temperature resistant mineral oil or molten salt; the heat conducting medium performs closed circulation in the system, and a cooler is arranged on the circulation pipeline; the cooling medium of the cooler is selected from brine, water and chlorobenzene, preferably brine and chlorobenzene; the heat-conducting medium storage tank is arranged in the system, and all heat-conducting medium in the system can be recovered and stored.
In the process of phosgene synthesis and active carbon catalyst online regeneration, in the step 1), multipoint thermometers are arranged in the inner part of the synthesis tower, the number of the multipoint thermometers is 1 multipoint thermometer/200 pipes to 1 multipoint thermometer/100 pipes, and the multipoint thermometers are uniformly distributed and used for monitoring the radial hot spot temperature condition of the synthesis tower; the number of temperature measuring points on the multipoint thermometer is selected from 4/m to 10/m, and the temperature measuring points are uniformly distributed.
The catalyst adopted in the step 1) is high-activity renewable active carbon, and the phosgene synthesis activity evaluation method of the active carbon is used for evaluation, and the specific method is as follows: sieving the powder and the crushed particles of the activated carbon, and dehydrating for 2 hours at 110 ℃ in a nitrogen atmosphere to obtain the activated carbon with the water content lower than 0.5%; filling the activated carbon into a tube array, heating the activated carbon in the tube array by adopting an electric heating furnace, and maintaining the temperature of the activated carbon in the tube array to be constant at 50 ℃; introducing a chlorine/nitrogen mixed gas at the inlet of the tube array, wherein the volume ratio of the chlorine in the mixed gas is 10%, the residence time of the mixed gas in the activated carbon bed layer is 60s, so that the activated carbon fully adsorbs the chlorine, the concentration of the chlorine in the mixed gas at the outlet is detected by adopting an ultraviolet-visible spectrum, when the concentration of the chlorine in the mixed gas is the same as that in the inlet gas, the introduction of the chlorine is stopped, and the chlorine adsorption quantity is calculated according to a concentration change curve measured by the ultraviolet-visible spectrum and is recorded as m1; and blowing out the chlorine in the tube array by adopting a small amount of nitrogen, and discharging the activated carbon. Heating the activated carbon which is adsorbed with chlorine to saturation to 325-375 ℃ by adopting an electric heating furnace, and introducing nitrogen at a certain speed at the inlet of a tube array, wherein the flow rate of the nitrogen is 10m/s, so that the chlorine adsorbed by the activated carbon is removed; loading the activated carbon after the chlorine is desorbed into a tube array, heating the activated carbon in the tube array by adopting an electric heating furnace, and maintaining the temperature of the activated carbon in the tube array to be constant at 50 ℃; introducing a chlorine/nitrogen mixed gas at the inlet of the tube array, wherein the volume ratio of the chlorine in the mixed gas is 10%, the residence time of the mixed gas in the activated carbon bed layer is 60s, so that the activated carbon fully adsorbs the chlorine, the concentration of the chlorine in the mixed gas at the outlet is detected by adopting an ultraviolet-visible spectrum, when the concentration of the chlorine in the mixed gas is the same as that in the inlet gas, the introduction of the chlorine is stopped, and the chlorine adsorption quantity is calculated according to a concentration change curve measured by the ultraviolet-visible spectrum and is recorded as m2; and blowing out the chlorine in the tube array by adopting a small amount of nitrogen, and discharging the activated carbon. The high activity renewable active carbon has m2/m1 value of 0.7-1, preferably 0.8-1.
The inventor finds that the temperature of temperature measuring points with different heights in the phosgene synthesis tower is gradually increased firstly under the normal condition by measuring the temperature in the phosgene synthesis tower, and then the temperature is rapidly increased after exceeding a certain temperature, and slowly decreased after being increased to the highest temperature point; the position of the highest temperature point is slowly moved away from the outlet as the operating time of the phosgene synthesis tower is prolonged. It is known that the phosgene synthesis reaction is exothermic, and that part of the heat, if not removed in time, is accumulated in the gas and activated carbon, and as the temperature increases, the rate of the phosgene synthesis reaction further increases, so that the phosgene synthesis reaction can be regarded as a self-accelerating reaction with a lower adiabatic or heat removal rate. The inventor considers that the active carbon from the inlet to the point of the sharp temperature rise belongs to the active carbon with lower catalytic activity, and the reaction progress of phosgene synthesis in the part of active carbon is lower, so the temperature rise is very slow; as the operating time of the phosgene synthesis tower is prolonged, the amount of the active carbon with lower catalytic activity of the part is continuously increased, so that the highest temperature point is continuously moved backwards. Thus, the proper point in time for the activated carbon regeneration process to be performed can be indicated by establishing a relationship between the distance from the inlet to the point of rapid temperature rise and the free chlorine content in the synthesized phosgene at the outlet of the phosgene synthesis tower.
In the process of phosgene synthesis and on-line regeneration of the active carbon catalyst, in the step 2), the position of the highest temperature point in the active carbon bed in the phosgene synthesis tower is moved to a certain position, and is obtained by measuring the content of free chlorine in the outlet phosgene, and the specific guidance is that when the content of the free chlorine in the outlet synthesized phosgene is higher than a certain value, the active carbon in the phosgene synthesis tower is converted into inactive active carbon, the distance between the highest temperature point in the bed and the inlet of a column tube of the phosgene synthesis tower is 1.5-3.2m, and the content of the chlorine in the phosgene at the outlet of the corresponding reactor is 300-1500ppm.
In the process of phosgene synthesis and on-line regeneration of the activated carbon catalyst, before the deactivated activated carbon is regenerated on line by adopting high-temperature carbon monoxide and high-temperature nitrogen in the step 2), a shell side heat conducting medium of a phosgene synthesis tower needs to be recovered into a heat conducting medium storage tank, and the shell side is in a low-pressure or vacuum state through a vacuumizing system, so that heat dissipation of the shell side is avoided. The shell side pressure is selected from 20 to 80kpa (A), preferably 40 to 60kpa.
In the process of phosgene synthesis and on-line regeneration of the activated carbon catalyst, in the step 2), high-temperature carbon monoxide is adopted to carry out desorption treatment on weakly adsorbed chlorine in the activated carbon bed, and the heating temperature of the high-temperature carbon monoxide is selected from 200-400 ℃, preferably 250-350 ℃, more preferably 275-325 ℃; the axial flow rate of the carbon monoxide in the activated carbon bed layer is 10-20m/s, preferably 12-18m/s; the carbon monoxide desorption treatment time is selected from 2-12 hours, preferably 4-10 hours;
In the process of phosgene synthesis and on-line regeneration of the activated carbon catalyst, in the step 2), high-temperature nitrogen is adopted to carry out desorption treatment on the chlorine gas which is strongly adsorbed in the activated carbon bed layer and to carry out removal treatment on chlorine-containing impurities which are strongly combined with the activated carbon, and the heating temperature of the high-temperature nitrogen is selected from 400-600 ℃, preferably 450-550 ℃, more preferably 475-525 ℃; the axial flow rate of nitrogen in the activated carbon bed layer is 5-15m/s, preferably 8-12m/s; the nitrogen desorption treatment time is selected from 24-48 hours, preferably 32-40 hours.
In the process of phosgene synthesis and on-line regeneration of the activated carbon catalyst, in the step 2), the iodine adsorption value of the activated carbon after on-line regeneration is increased to 70-90% of that of fresh activated carbon, and the total carbon content is 85-95%.
In the process of phosgene synthesis and on-line regeneration of the activated carbon catalyst, in the step 2), after fresh chlorine and carbon monoxide are added again to carry out phosgene synthesis reaction through the activated carbon after on-line regeneration, the ratio of the distance between the hot spot temperature position in the activated carbon bed layer and the inlet of the tubulation to the total length of the tubulation is between 0.1 and 0.4, and the content of free chlorine in the synthesized phosgene at the outlet is lower than 500ppm.
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
The chlorine content in phosgene was determined using the following method:
(1) Detection principle:
Cl2+2KI→2KCl+I2
I2+2Na2S2O3→2NaI+Na2S4O6
(2) The detection process comprises the following steps:
Preparing enough KI solution, freezing a phosgene sampling bottle, connecting the phosgene sampling bottle with a glass funnel, adding the KI solution into the glass funnel, opening a connecting valve in the middle to enable the KI solution to fully absorb chlorine in phosgene, and titrating with a prepared Na 2S2O3 standard solution until the KI solution is changed from mauve to colorless.
(3) Method for calculating chlorine in phosgene
Wherein Cl is the content of chlorine in phosgene, mg/L;
v 1 is the volume of Na 2S2O3 standard solution consumed by titration, ml;
V 2 is the volume of the gas sampling bottle, L;
C is the actual concentration of Na 2S2O3 standard solution and mol/L.
The iodine adsorption value in the activated carbon is measured by referring to national standard GB/T12496.8-1999;
the total carbon content of the activated carbon is measured by a solid TOC analyzer;
The phosgene synthesis activity index m2/m1 of the activated carbon is measured by the following method:
Sieving the powder and the crushed particles of the activated carbon, and dehydrating for 2 hours at 110 ℃ in a nitrogen atmosphere to obtain the activated carbon with the water content lower than 0.5%; filling the activated carbon into a tube array, heating the activated carbon in the tube array by adopting an electric heating furnace, and maintaining the temperature of the activated carbon in the tube array to be constant at 50 ℃; introducing a chlorine/nitrogen mixed gas at the inlet of the tube array, wherein the volume ratio of the chlorine in the mixed gas is 10%, the residence time of the mixed gas in the activated carbon bed layer is 60s, so that the activated carbon fully adsorbs the chlorine, the concentration of the chlorine in the mixed gas at the outlet is detected by adopting an ultraviolet-visible spectrum, when the concentration of the chlorine in the mixed gas is the same as that in the inlet gas, the introduction of the chlorine is stopped, and the chlorine adsorption quantity is calculated according to a concentration change curve measured by the ultraviolet-visible spectrum and is recorded as m1; and blowing out the chlorine in the tube array by adopting a small amount of nitrogen, and discharging the activated carbon.
Heating the activated carbon which is adsorbed with chlorine to saturation to 350 ℃ by adopting an electric heating furnace, and introducing nitrogen at a certain speed at the inlet of the tube array, wherein the flow rate of the nitrogen is 10m/s, so that the chlorine adsorbed by the activated carbon is removed;
Loading the activated carbon after the chlorine is desorbed into a tube array, heating the activated carbon in the tube array by adopting an electric heating furnace, and maintaining the temperature of the activated carbon in the tube array to be constant at 50 ℃; introducing a chlorine/nitrogen mixed gas at the inlet of the tube array, wherein the volume ratio of the chlorine in the mixed gas is 10%, the residence time of the mixed gas in the activated carbon bed layer is 60s, so that the activated carbon fully adsorbs the chlorine, the concentration of the chlorine in the mixed gas at the outlet is detected by adopting an ultraviolet-visible spectrum, when the concentration of the chlorine in the mixed gas is the same as that in the inlet gas, the introduction of the chlorine is stopped, and the chlorine adsorption quantity is calculated according to a concentration change curve measured by the ultraviolet-visible spectrum and is recorded as m2; and blowing out the chlorine in the tube array by adopting a small amount of nitrogen, and discharging the activated carbon.
The activated carbon powders used for blending in examples 1,2 and 3 below were prepared by pulverizing activated carbon commercially available from NORIT under the trademark RB 4C.
Example 1
Under the protection of nitrogen, adding anhydrous ZnCl 2 with the molar ratio of 5:1 as a catalyst into the 1, 4-dicyanobenzene to react for 40 hours at 500 ℃ to obtain black powder. The powder is washed 3 times by adopting 2% dilute hydrochloric acid with the mass ratio of 1:20 (powder: cleaning agent), and is washed 2 times by adopting deionized water with the mass ratio of 1:75, and unreacted raw materials are removed. The obtained carbon powder and the commercial activated carbon powder are mixed according to the mass ratio of 1:1. And (3) heating and refluxing the powder in a 10% nitric acid solution at 100 ℃ for 3 hours for pickling, removing metal ions in the activated carbon, cleaning the pickled powder for 3 times by adopting deionized water with the mass ratio of 1:50, and then drying the powder to constant weight in a nitrogen atmosphere at 140 ℃. Sequentially adding polyvinyl alcohol and glutaraldehyde hydrochloric acid solution into the mixed powder, wherein the mass ratio of the polyvinyl alcohol to the glutaraldehyde is 30:1, the molecular weight of the polyvinyl alcohol is 150000, the mass concentration of the glutaraldehyde hydrochloric acid solution is 0.5%, and the mass ratio of the adhesive solution to the carbon powder is 10:1; the mixed powder was kneaded and extruded into a bar having a diameter of 4mm and a length of 7 mm. Curing for 5h at 25 ℃, drying for 24h at 80 ℃ and then roasting in argon atmosphere, wherein the roasting temperature is 1000 ℃ and the roasting time is 1h.
Example 2
Under the protection of nitrogen, adding anhydrous ZnCl 2 with the molar ratio of 3:1 as a catalyst into the 1, 4-dicyanobenzene to react for 55 hours at 400 ℃ to obtain black powder. The powder is washed 1 time by adopting 2% dilute hydrochloric acid with the mass ratio of 1:20 (powder: cleaning agent), and is washed 1 time by adopting deionized water with the mass ratio of 1:50, and unreacted raw materials are removed. The obtained carbon powder and the commercial activated carbon powder are mixed according to the mass ratio of 1:4. And (3) heating and refluxing the powder in a 10% nitric acid solution at 100 ℃ for 4 hours for pickling, removing metal ions in the activated carbon, cleaning the pickled powder for 2 times by adopting deionized water with the mass ratio of 1:25, and then drying the powder to constant weight in a nitrogen atmosphere at 100 ℃. The carbon powder and the binder are uniformly mixed and kneaded into a plastic blank, extruded to form strips, cured, dried and roasted to obtain the active carbon suitable for phosgene synthesis. Sequentially adding polyvinyl alcohol and glutaraldehyde hydrochloric acid solution into the mixed powder, wherein the mass ratio of the polyvinyl alcohol to the glutaraldehyde is 10:1, the molecular weight of the polyvinyl alcohol is 20000, the mass concentration of the glutaraldehyde hydrochloric acid solution is 5%, and the mass ratio of the adhesive solution to the carbon powder is 15:1; the mixed powder was kneaded and extruded into a bar having a diameter of 1mm and a length of 10 mm. Curing at 20 ℃ for 1h, drying at 150 ℃ for 1h, and then roasting in an argon atmosphere at 850 ℃ for 3h.
Example 3
Under the protection of nitrogen, 1, 4-dicyanobenzene is added with anhydrous ZnCl 2 with the molar ratio of 7:1 as a catalyst, and the mixture is reacted for 30 hours at 300 ℃ to obtain black powder. The powder is washed for 2 times by adopting 2% dilute hydrochloric acid with the mass ratio of 1:20 (powder: cleaning agent), and is washed for 3 times by adopting deionized water with the mass ratio of 1:25, and unreacted raw materials are removed. The obtained carbon powder and the commercial activated carbon powder are mixed according to the mass ratio of 1:2.5. And (3) heating and refluxing the powder in a 10% nitric acid solution at 100 ℃ for 2 hours for pickling, removing metal ions in the activated carbon, cleaning the pickled powder for 1 time by adopting deionized water with the mass ratio of 1:75, and then drying the powder to constant weight in a nitrogen atmosphere at 120 ℃. The carbon powder and the binder are uniformly mixed and kneaded into a plastic blank, extruded to form strips, cured, dried and roasted to obtain the active carbon suitable for phosgene synthesis. Sequentially adding polyvinyl alcohol and glutaraldehyde hydrochloric acid solution into the mixed powder, wherein the mass ratio of the polyvinyl alcohol to the glutaraldehyde is 50:1, the molecular weight of the polyvinyl alcohol is 80000, the mass concentration of the glutaraldehyde hydrochloric acid solution is 20%, and the mass ratio of the adhesive solution to the carbon powder is 5:1; the mixed powder was kneaded and extruded into a bar having a diameter of 5mm and a length of 1 mm. Curing at 30 deg.c for 3 hr, drying at 120 deg.c for 12 hr, and roasting in argon atmosphere at 700 deg.c for 5 hr.
The highly active activated carbon prepared in examples 1,2,3 was applied to industrial use, and the method of use and regeneration process thereof are described in examples 4,5, 6.
Example 4
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tube type fixed bed reactor, the length of a tube is 3m, an activated carbon catalyst is filled in the tube, the catalyst prepared in the embodiment 1 is prepared by adopting the activated carbon evaluation method, the m2/m1 value is 0.86, a plurality of temperature meters are arranged in part of the tube, the number of the installed temperature meters is 1/100 tube, the density of temperature measuring points on the temperature meters is 6/m, and high-temperature-resistant mineral oil is adopted outside the tube for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium which is cooled by a cooler and absorbs the reaction heat, and the heat conducting medium is brine.
When the temperature position of a hot spot in an active carbon bed layer in the phosgene synthesis tower is more than 2m away from the inlet of the tube array, the content of residual chlorine gas in synthesized phosgene is higher than 300ppm, which indicates that the active carbon in the phosgene synthesis tower is converted into inactive active carbon; the run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured. At this time, it is necessary to recover the shell-side heat transfer medium of the phosgene synthesis tower into the heat transfer medium storage tank and to set the shell-side pressure to 50kpaA by the vacuum system. Desorbing weakly adsorbed chlorine in the activated carbon bed by using carbon monoxide at 350 ℃; the axial flow velocity of carbon monoxide in the activated carbon bed layer is 15m/s; the desorption treatment time of carbon monoxide is 2 hours; next, desorbing the chlorine gas strongly adsorbed in the activated carbon bed layer by adopting nitrogen at 500 ℃ and removing chlorine-containing impurities strongly combined with the activated carbon; the axial flow velocity of nitrogen in the activated carbon bed layer is 10m/s; the nitrogen desorption treatment time is 36h;
And after the activated carbon is regenerated, referring to the operation process parameters before regeneration, measuring the hot spot temperature position of the activated carbon bed layer in the tubulation and the content of free chlorine in the outlet phosgene.
Example 5
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tube type fixed bed reactor, the length of the tube is 5m, an activated carbon catalyst is filled in the tube, the catalyst prepared in the embodiment 2 adopts the activated carbon evaluation method m2/m1 value of 0.77, a plurality of temperature meters are arranged in part of the tube, the number of the temperature meters is 1/150 tube, the density of temperature measuring points on the temperature meters is 4/m, and high-temperature resistant silicone oil is adopted outside the tube for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium which is cooled by a cooler and absorbs the reaction heat, and the heat conducting medium is water.
When the temperature position of a hot spot in the active carbon bed layer in the phosgene synthesis tower is more than 3.2m away from the inlet of the row pipe, the content of residual chlorine gas in the phosgene is higher than 1500ppm, which indicates that the active carbon in the phosgene synthesis tower is converted into inactive active carbon; the run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured. At this time, it is necessary to recover the shell-side heat transfer medium of the phosgene synthesis tower into the heat transfer medium storage tank and to set the shell-side pressure to 80kpaA by the vacuum system. Carrying out desorption treatment on weakly adsorbed chlorine in the activated carbon bed by adopting carbon monoxide at 300 ℃; the axial flow velocity of carbon monoxide in the activated carbon bed layer is 10m/s; the desorption treatment time of carbon monoxide is 8 hours; next, desorbing the chlorine gas strongly adsorbed in the activated carbon bed layer by adopting nitrogen at 400 ℃ and removing chlorine-containing impurities strongly combined with the activated carbon; the axial flow velocity of nitrogen in the activated carbon bed layer is 8m/s; the nitrogen desorption treatment time is 44h;
And after the activated carbon is regenerated, referring to the operation process parameters before regeneration, measuring the hot spot temperature position of the activated carbon bed layer in the tubulation and the content of free chlorine in the outlet phosgene.
Example 6
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tubular fixed bed reactor, the length of a tubular is 2m, an activated carbon catalyst is filled in the tubular, the catalyst prepared in the embodiment 3 adopts the activated carbon evaluation method m2/m1 value of 0.81, a plurality of temperature meters are arranged in part of the tubular, the number of the installed temperature meters is 1/200 tubular, the density of temperature measuring points on the temperature meters is 8/m, and high-temperature resistant silicone oil is adopted outside the tubular for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium cooled by a cooler and absorbing reaction heat, and the heat conducting medium is chlorobenzene.
When the temperature position of a hot spot in an active carbon bed layer in the phosgene synthesis tower is more than 1.5m away from the inlet of the row pipe, and the content of residual chlorine gas in the phosgene is higher than 750ppm, the active carbon in the phosgene synthesis tower is converted into inactive active carbon; the run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured. At this time, it is necessary to recover the shell-side heat transfer medium of the phosgene synthesis tower into the heat transfer medium storage tank and to set the shell-side pressure to 20kpaA by the vacuum system. Carbon monoxide at 200 ℃ is adopted to carry out desorption treatment on the weakly adsorbed chlorine in the activated carbon bed layer; the axial flow velocity of carbon monoxide in the activated carbon bed layer is 20m/s; the desorption treatment time of carbon monoxide is 12 hours; next, desorbing the chlorine gas strongly adsorbed in the activated carbon bed layer by adopting nitrogen at 600 ℃ and removing chlorine-containing impurities strongly combined with the activated carbon; the axial flow velocity of nitrogen in the activated carbon bed layer is 15m/s; the nitrogen desorption treatment time is 28h;
And after the activated carbon is regenerated, referring to the operation process parameters before regeneration, measuring the hot spot temperature position of the activated carbon bed layer in the tubulation and the content of free chlorine in the outlet phosgene.
Comparative example 1
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tubular fixed bed reactor, the length of a tubular is 3m, an activated carbon catalyst is filled in the tubular, the catalyst is a commercially available activated carbon catalyst with the trade mark of NORIT RB C, the catalyst adopts the activated carbon evaluation method m2/m1 value of 0.65, a plurality of temperature meters are arranged in part of the tubular, the number of the temperature meters is 1/100 tubular, the density of temperature measuring points on the temperature meters is 6/m, and high-temperature-resistant mineral oil is adopted outside the tubular for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium which is cooled by a cooler and absorbs the reaction heat, and the heat conducting medium is brine.
When the temperature position of a hot spot in the active carbon bed layer in the phosgene synthesis tower is more than 2m away from the inlet of the tube array, the content of residual chlorine gas in synthesized phosgene is higher than 300ppm, which indicates that the active carbon in the phosgene synthesis tower is converted into inactive active carbon. The run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured.
Comparative example 2
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tubular fixed bed reactor, the length of a tubular is 5m, an activated carbon catalyst is filled in the tubular, the catalyst is a commercially available activated carbon catalyst with the trade mark of NORIT RB C, the catalyst adopts the activated carbon evaluation method m2/m1 value of 0.65, a plurality of temperature gauges are arranged in part of the tubular, the number of the installed temperature gauges is 1/150 tubular, the density of temperature measuring points on the temperature gauges is 4/m, and high-temperature resistant silicone oil is adopted outside the tubular for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium which is cooled by a cooler and absorbs the reaction heat, and the heat conducting medium is water.
When the temperature position of a hot spot in the active carbon bed layer in the phosgene synthesis tower is more than 3.2m away from the inlet of the row pipe, the content of residual chlorine gas in the phosgene is higher than 1500ppm, which indicates that the active carbon in the phosgene synthesis tower is converted into inactive active carbon. The run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured.
Comparative example 3
Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine under the action of a catalyst to synthesize phosgene; the phosgene synthesis tower is a tubular fixed bed reactor, the length of a tubular is 2m, an activated carbon catalyst is filled in the tubular, the activated carbon catalyst is a commercially available activated carbon catalyst with the trade mark of NORIT RB C, the m2/m1 value of the activated carbon evaluation method is 0.65, a plurality of temperature-measuring meters are arranged in part of the tubular, the number of the temperature-measuring meters is 1/200 tubular, the density of temperature-measuring points on the temperature-measuring meters is 8/m, and high-temperature-resistant silicone oil is adopted outside the tubular for absorbing reaction heat generated by synthesizing phosgene; the phosgene synthesis system is internally provided with a heat conducting medium cooled by a cooler and absorbing reaction heat, and the heat conducting medium is chlorobenzene.
When the temperature position of a hot spot in the active carbon bed layer in the phosgene synthesis tower is more than 1.5m away from the inlet of the row pipe, the content of residual chlorine gas in the phosgene is higher than 750ppm, which indicates that the active carbon in the phosgene synthesis tower is converted into inactive active carbon. The run time from the time of the activated carbon administration to the time of reaching the deactivated state was calculated, and the volume loss amount of the activated carbon in the column tube was measured.
TABLE 1 industrialized application Effect of synthetic activated carbon
As can be seen from the table, the prepared high-activity activated carbon has longer service life, and compared with the commercial phosgene synthetic activated carbon, the operation period is improved by more than 50%, and the high-activity activated carbon has good significance for prolonging the operation period of a phosgene synthetic tower and avoiding frequent shutdown and overhaul.
TABLE 2 analysis index before and after regeneration of activated carbon
TABLE 3 phosgene Synthesis operating parameters before and after activated carbon regeneration
From the above table, it can be seen that the activated carbon regeneration process has a good effect on removing chlorine-containing impurities from the activated carbon, and the catalytic activity of the activated carbon is recovered. The regenerated active carbon is used for producing phosgene, the temperature of a hot spot in an active carbon bed layer is obviously advanced, the catalytic activity of the active carbon is recovered, and the content of free chlorine in a phosgene product is greatly reduced. The on-line regeneration process of the activated carbon can reduce the shutdown maintenance time of the phosgene synthesis tower from 15-30 days to 2-3 days due to the deactivation of the activated carbon, and the safety risk of the untreated complete phosgene leakage caused by the opening of the phosgene synthesis tower is avoided, so that the method has good implementation effect and significance.
Claims (24)
1. A method for preparing high-activity renewable active carbon for phosgene synthesis, which is characterized by comprising the following steps:
1) Under the protection of inert gas, reacting a nitrogenous aromatic ring compound at a high temperature for a certain time by taking anhydrous ZnCl 2 as a catalyst to obtain black powder; washing the powder to remove unreacted raw materials, mixing the powder with ordinary carbon powder according to a certain proportion, further removing metal ions by acid washing at a certain temperature, washing the powder, and drying to obtain raw material carbon powder;
2) And uniformly mixing raw material carbon powder and a binder, kneading, extruding to form strips, curing, drying and roasting to obtain the active carbon suitable for phosgene synthesis.
2. The method according to claim 1, characterized in that: in the step 1), the nitrogen-containing aromatic ring compound is one or more of 1, 4-dicyanobenzene, 2, 6-naphthalonitrile and 1,3, 5-3-cyanobenzene, the molar ratio of the nitrogen-containing aromatic ring compound to anhydrous ZnCl 2 serving as a catalyst is selected from 3:1-7:1, the inert gas is nitrogen, and/or the reaction temperature is 300-500 ℃ and the reaction time is 20-60h.
3. The method according to claim 1 or 2, characterized in that: in the step 1), the method for cleaning the unreacted raw materials in the powder comprises the steps of cleaning the raw materials by using 2% dilute hydrochloric acid with the mass of 10-30 times of that of the powder, and cleaning the raw materials by using deionized water with the mass of 25-75 times of that of the powder.
4. The method according to claim 1 or 2, characterized in that: in the step 1), the carbon powder used for blending is commercially available coconut shell activated carbon or coal-based activated carbon powder, and the blending proportion is the carbon powder prepared from the nitrogenous aromatic ring compound in the step 1): the mass ratio of the commercial active carbon powder is 1:1-1:4.
5. The method according to claim 1 or 2, characterized in that: in the step 1), the method for removing metal ions in the powder by acid washing is that the powder is heated and refluxed in 10% nitric acid solution at 90-100 ℃ for 1-4h, the acid washed powder is washed by deionized water with the mass of 25-75 times of that of the powder, and then the powder is dried to constant weight in nitrogen atmosphere at 100-150 ℃.
6. The method according to claim 1 or 2, characterized in that: the activity of the activated carbon is characterized by m2/m1, and the value of m2/m1 is 0.7-1; the evaluation method comprises the following steps: and (3) measuring the saturated chlorine adsorption value of the activated carbon to be m1, desorbing the activated carbon saturated by chlorine adsorption at 325-375 ℃ by adopting nitrogen, repeatedly measuring the saturated chlorine adsorption value of the activated carbon to be m2, and calculating the m2/m1 value.
7. The method according to claim 6, wherein: the m2/m1 value is 0.8-1.
8. A method for synthesizing phosgene and regenerating an active carbon catalyst on line, which comprises the following steps:
1) Introducing the pre-mixed CO and chlorine into a phosgene synthesis tower, and reacting the CO and the chlorine to synthesize phosgene under the action of the catalyst prepared by the method of any one of claims 1-5;
2) When the highest temperature point in the active carbon bed layer in the phosgene synthesis tower moves to a certain position, the activity of synthesizing active carbon phosgene is reduced, the content of residual chlorine in synthesized phosgene is increased, and the active carbon in the phosgene synthesis tower is converted into inactive active carbon; at the moment, the active carbon is regenerated on line, the light gas synthesizing tower system is pretreated, and then the deactivated active carbon is regenerated on line by adopting high-temperature carbon monoxide and high-temperature nitrogen.
9. The method according to claim 8, wherein in step 1), an electric heater is provided at an inlet of the phosgene synthesis tower to heat carbon monoxide or nitrogen to 300-600 ℃; and/or the phosgene synthesis tower is in two stages, the first stage is a tubular fixed bed reactor, and the second stage is a bulk fixed bed reactor; and/or, the shell side of the first-stage phosgene synthesis tower is provided with a vacuumizing system for vacuumizing the space at the shell side to form a negative pressure or vacuum environment; and/or a multipoint thermometer is arranged in the first-stage phosgene synthesis tower and used for monitoring the temperature of the activated carbon bed layer in the tube array.
10. The method according to claim 8 or 9, wherein in step 2), when the activated carbon in the phosgene synthesis tower is converted into deactivated activated carbon, the position of the highest temperature point in the activated carbon bed in the phosgene synthesis tower is moved back to a distance of 1.5-3.2m from the inlet of the tubular reactor filled with activated carbon, and the content of chlorine contained in phosgene at the outlet of the corresponding reactor is 300-1500ppm.
11. The method according to claim 8, wherein in step 2), the operation of pretreating the light gas synthesizing column system is: and recycling the shell-side heat conducting medium of the phosgene synthesis tower into a heat conducting medium storage tank, and enabling the shell side to be in a low-pressure or vacuum state through a vacuumizing system so as to avoid heat dissipation of the shell side, wherein the shell side pressure is selected from 20-80kpa (A).
12. The method of claim 11, wherein the shell side pressure in step 2) is selected from the group consisting of 40-60kpa (a).
13. The method according to claim 8, wherein in step 2), weakly adsorbed chlorine gas in the activated carbon bed is desorbed with high temperature carbon monoxide, the carbon monoxide being heated at a temperature selected from the range of 200 to 400 ℃; the axial flow velocity of carbon monoxide in the activated carbon bed layer is 10-20m/s; the desorption treatment time of the carbon monoxide is 2-12h.
14. The method according to claim 13, wherein in step 2) the heating temperature of the carbon monoxide is selected from 250-350 ℃.
15. The method according to claim 13, wherein in step 2) the heating temperature of the carbon monoxide is selected from 275-325 ℃.
16. The process according to claim 13, wherein in step 2) the carbon monoxide has a flow rate in the active carbon bed of from 12 to 18m/s.
17. The method according to claim 13, wherein in step 2), the carbon monoxide desorption treatment time is 4 to 10 hours.
18. The method according to claim 8, wherein in step 2), chlorine-containing impurities strongly bonded to the activated carbon in the activated carbon bed are removed by high-temperature nitrogen gas, and the heating temperature of the nitrogen gas is selected from 400-600 ℃; the axial flow velocity of nitrogen in the activated carbon bed layer is 5-15m/s; the nitrogen desorption treatment time is 24-48h.
19. The method according to claim 18, wherein in step 2) the heating temperature of the nitrogen gas is selected from 450-550 ℃.
20. The method of claim 18, wherein in step 2) the nitrogen is heated at a temperature selected from 475-525 ℃.
21. The method according to claim 18, wherein in step 2) the nitrogen gas has a axial flow rate in the activated carbon bed of 8-12m/s.
22. The method of claim 18, wherein in step 2), the nitrogen desorption treatment time is 32 to 40 hours.
23. The method according to claim 8, wherein in step 2), the activated carbon after on-line regeneration has an iodine adsorption value raised to a level of 70-90% of fresh activated carbon and a total carbon content of 85-95%.
24. The method according to claim 8, wherein in step 2), after the online regeneration of the activated carbon, fresh chlorine and carbon monoxide are added again to perform phosgene synthesis reaction, the ratio of the distance from the hot spot temperature position in the activated carbon bed layer to the inlet of the column tube to the total length of the column tube is between 0.1 and 0.4, and the content of free chlorine in the synthesized phosgene at the outlet is lower than 500ppm.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103127823A (en) * | 2013-02-22 | 2013-06-05 | 邹炎 | Modular flue gas cleaning device with in-situ regeneration function, and regeneration method |
| CN104415770A (en) * | 2013-08-26 | 2015-03-18 | 万华化学集团股份有限公司 | Catalyst for preparing phosgene and method for preparing phosgene |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106040210B (en) * | 2016-06-30 | 2019-04-12 | 华中科技大学 | A kind of demercuration method and device activated online based on active carbon |
| CN111760581B (en) * | 2019-08-30 | 2021-07-23 | 万华化学（宁波）有限公司 | Catalyst for preparing phosgene, preparation method thereof and method for preparing phosgene and comprehensively utilizing energy |
| EP4115975A4 (en) * | 2020-03-03 | 2024-05-15 | Takasago International Corporation | Catalyst containing activated carbon on which ruthenium complex is adsorbed, and method for producing reduction product using same |
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| CN104415770A (en) * | 2013-08-26 | 2015-03-18 | 万华化学集团股份有限公司 | Catalyst for preparing phosgene and method for preparing phosgene |
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