EP0204910B1 - Process for the chemical-thermal decomposition of halogenated hydrocarbons - Google Patents
Process for the chemical-thermal decomposition of halogenated hydrocarbons Download PDFInfo
- Publication number
- EP0204910B1 EP0204910B1 EP86104351A EP86104351A EP0204910B1 EP 0204910 B1 EP0204910 B1 EP 0204910B1 EP 86104351 A EP86104351 A EP 86104351A EP 86104351 A EP86104351 A EP 86104351A EP 0204910 B1 EP0204910 B1 EP 0204910B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- silicates
- halogenated hydrocarbons
- calcium
- reaction
- chemical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 150000008282 halocarbons Chemical group 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000005979 thermal decomposition reaction Methods 0.000 title description 10
- 238000006243 chemical reaction Methods 0.000 claims abstract description 29
- 239000007787 solid Substances 0.000 claims abstract description 22
- 239000011575 calcium Substances 0.000 claims abstract description 20
- 235000012241 calcium silicate Nutrition 0.000 claims abstract description 14
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 12
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000000391 magnesium silicate Substances 0.000 claims abstract description 6
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 5
- 239000011261 inert gas Substances 0.000 claims abstract description 5
- 235000012243 magnesium silicates Nutrition 0.000 claims abstract description 5
- 239000007789 gas Substances 0.000 claims description 15
- 150000004760 silicates Chemical class 0.000 claims description 13
- 239000004568 cement Substances 0.000 claims description 10
- 239000004567 concrete Substances 0.000 claims description 7
- 229910052610 inosilicate Inorganic materials 0.000 claims description 2
- 239000004571 lime Substances 0.000 claims description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims 1
- 235000011941 Tilia x europaea Nutrition 0.000 claims 1
- 229910052615 phyllosilicate Inorganic materials 0.000 claims 1
- 229910052645 tectosilicate Inorganic materials 0.000 claims 1
- 150000003071 polychlorinated biphenyls Chemical class 0.000 description 15
- 239000008187 granular material Substances 0.000 description 12
- 239000000126 substance Substances 0.000 description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 8
- -1 Ca 2 Si0 4 Chemical class 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 239000000292 calcium oxide Substances 0.000 description 6
- 235000012255 calcium oxide Nutrition 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000000378 calcium silicate Substances 0.000 description 5
- 229910052918 calcium silicate Inorganic materials 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 4
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 4
- 239000007795 chemical reaction product Substances 0.000 description 4
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 description 4
- 229930195733 hydrocarbon Natural products 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000011398 Portland cement Substances 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 150000004826 dibenzofurans Chemical class 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 150000002367 halogens Chemical group 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000002207 metabolite Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910004706 CaSi2 Inorganic materials 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 239000006004 Quartz sand Substances 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 150000007514 bases Chemical class 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 239000011455 calcium-silicate brick Substances 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000005237 degreasing agent Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- BCAARMUWIRURQS-UHFFFAOYSA-N dicalcium;oxocalcium;silicate Chemical compound [Ca+2].[Ca+2].[Ca]=O.[O-][Si]([O-])([O-])[O-] BCAARMUWIRURQS-UHFFFAOYSA-N 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 150000002240 furans Chemical class 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910000039 hydrogen halide Inorganic materials 0.000 description 1
- 239000012433 hydrogen halide Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 235000019792 magnesium silicate Nutrition 0.000 description 1
- 229910052919 magnesium silicate Inorganic materials 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 238000010327 methods by industry Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000011224 oxide ceramic Substances 0.000 description 1
- 229910052574 oxide ceramic Inorganic materials 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000003380 propellant Substances 0.000 description 1
- 238000011002 quantification Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 235000019976 tricalcium silicate Nutrition 0.000 description 1
- 229910021534 tricalcium silicate Inorganic materials 0.000 description 1
- 238000004056 waste incineration Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000010456 wollastonite Substances 0.000 description 1
- 229910052882 wollastonite Inorganic materials 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D3/00—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
- A62D3/40—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by heating to effect chemical change, e.g. pyrolysis
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D3/00—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
- A62D3/30—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
- A62D3/34—Dehalogenation using reactive chemical agents able to degrade
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
- A62D2101/20—Organic substances
- A62D2101/22—Organic substances containing halogen
-
- 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S588/00—Hazardous or toxic waste destruction or containment
- Y10S588/901—Compositions
Definitions
- the invention relates to a process for the chemical-thermal decomposition of halogenated hydrocarbons in an inert gas atmosphere, in particular of higher halogenated hydrocarbons, by reaction with a stoichiometric amount of alkaline solid substances at elevated temperatures in a reactor.
- halogenated hydrocarbons are very often used in industry and research.
- fluorocarbons serve as propellants and refrigerants and are the starting materials for the production of chemically very resistant plastics.
- Chlorinated hydrocarbons are used in large quantities as degreasing agents in metal processing plants. Further areas of application are chemical cleaning of all kinds.
- the chlorinated hydrocarbons are raw materials for the production of polymers, pesticides and herbicides.
- the polychlorinated hydrocarbons were used as heat transfer oils or hydraulic fluids due to their high chemical and thermal resistance.
- the polychlorinated biphenyls (PCB) are typical representatives of this class of substances.
- DE-OS 30 28 193 describes a process for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances, which are reacted with calcium oxide / calcium hydroxide in a superstoichiometric ratio at temperatures of 300 to 800 ° C. in a reactor.
- So-called island silicates such as Ca 2 Si0 4 , Ca s Si 2 0 7 and Ca 3 Si 3 0 9 , chain silicates such as CaSi0 3 , band silicates such as Ca 3 Si 4 0 11 are preferably used as calcium silicates or magnesium , or network silicates such as CaSi 2 0 5 are used.
- These silicates can be found as naturally occurring minerals such as e.g. B. wollastonite or tobororite used or manufactured synthetically. During production, however, care must be taken to ensure that the melting points of the silicates in question are not reached, in order to avoid that a glass-like solidified product with only a small surface area and porosity is formed.
- magnesium silicates can equally well be used, it being possible for some of the calcium or magnesium in the silicate to be substituted by other metal cations, such as iron.
- synthetic silicates or silicate hydrates of calcium or magnesium can be used, which contain free excess calcium oxide or magnesium oxide.
- the chemical reaction of the halogenated hydrocarbons with silicates is less exothermic than the comparable reaction with calcium oxide, so that a lower temperature increase in the reactor results at comparable metering rates. This can be important for the reactor because of the choice of material.
- halogenated hydrocarbons are reacted with the silicates in the presence of inert gas, preferably under normal pressure.
- silicates in the form of granules or in lumpy form has proven to be very cheap.
- Such granules can be produced by a simple pelletizing process, using commercially available cements or ground cement raw clinker and water as starting materials.
- the use of granules enables the reaction to be carried out in a wide variety of reactors.
- a cartridge can be filled with granules into which the halogenated hydrocarbon is metered in either liquid or gaseous after heating to a reaction temperature of 450-700 ° C.
- the chemical-thermal decomposition then takes place inside the bed, while the halogen-free exhaust gas flows unhindered through the granulate bed and can escape at the other end of the cartridge. After approximately 80-85% utilization of the granulate fill, it can then be renewed or, if the cartridge is designed accordingly, it can be completely replaced.
- cement clinker, sand-lime brick and / or gas concrete is used as the alkaline solid substance.
- a shaft furnace which contains a bed of calcium silicate granulate, which is designed as a moving bed, the halogenated hydrocarbon and the resulting exhaust gas flowing through the bed either in cocurrent or in countercurrent.
- porous calcium silicate in granulated form has proven to be very advantageous.
- Corresponding granules can be produced, for example, by crushing silicate-rich building materials, such as gas concrete blocks or sand-lime blocks. These materials are mechanically and thermally sufficiently stable to serve as a bed in a moving bed reactor and also have a very large surface area. This material can be converted almost stoichiometrically with the halogenated hydrocarbons based on the Ca content.
- the gaseous reaction products formed during the chemical-thermal decomposition of halogenated hydrocarbons with silicates are halogen-free.
- the exhaust gas contains corresponding amounts of hydrogen and methane and possibly other partly saturated partly unsaturated low hydrocarbons, as well as carbon monoxide and carbon dioxide.
- the exhaust gas still has a considerable calorific value and can be used accordingly or simply re-burned to carbon dioxide and water in an afterburning chamber.
- gas concrete which is in granular form with a main grain fraction of about 4 mm, are filled into a reaction tube made of aluminum oxide ceramic.
- the filled reaction tube is closed on both sides and vertically in a tube furnace. Fixed and heated to 700 ° C.
- a total of 70 g of polychlorinated biphenyls (PCB) with an average chlorine content of 60% by weight are then metered into the reaction tube from above via a capillary within 3 hours, and at the same time the reactor is preheated from top to bottom with nitrogen preheated to 650 ° C. at normal pressure flows through.
- the nitrogen volume flow is about 5 to 10 NI per hour. The nitrogen escapes together with the gaseous reaction products at the lower end of the reactor and is passed through a washing section.
- the exothermic reaction of the PCB with Ca silicate leads to a temperature increase in the reaction zone in the upper part of the bed.
- the approximately 820 to 850 ° C. hot reaction zone migrates downward, so that a temperature measurement can be used to determine at what point in time the capacity of the bed is exhausted.
- composition of the gas concrete used as the solid reactant was determined as a mixture of 58% by weight Ca 3 S! 2 0 7 . H 2 0 and 42 wt.% A-quartz determined.
- the chemical analysis of the implementation was based on the residue analysis of the washing solution and the analysis of the solid residue. With a detection limit of 20 p.g PCB in the wash solution, no PCB could be detected, from which a degree of conversion of> 99.99996% is calculated.
- the chemical-thermal decomposition of PCBs does not result in the formation of metabolites, such as chlorinated dibenzodioxins or dibenzofurans. The compounds mentioned could not be detected at a limit of quantification of 10 ng.
- the solid granules were free-flowing even after the reaction and showed no caking.
- the main components were Si02. and CaCl 2 .
- the solid residue also contained calcium silicate and small amounts of elemental carbon.
- the chlorine metered into the reactor in the form of PCB was quantitatively recovered as chloride after the chemical-thermal decomposition of the PCB in the solid residue.
- the exhaust gas was halogen-free and essentially contained CO and H 2 in addition to nitrogen.
- Example 2 Analogous to Example 1, but cement is used instead of gas concrete.
- a porous granulate was produced from the cement powder as follows: 300 g of Portland cement are mixed with 140 g of water. After a curing time of 24 hours, the test specimen is dried at 600 ° C, almost all of the mixing water being expelled from the test specimen. The cement body, broken up into small pieces after drying and cooling, serves as filling material for the reaction tube.
- test result is comparable to the results described in Examples 1 and 2.
- burnt lime 168 g are mixed with 60 g of quartz sand and finely ground. Then the mixture is mixed with water to a dough-like mass and mixed with 0.6 aluminum powder. The mass swells up within a short time. The sample is then heated to 200 ° C. in an autoclave in a steam atmosphere. A solid pore is created Product that is broken into granules with an average grain size of approx. 5 mm in a jaw crusher.
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Fire-Extinguishing Compositions (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Processing Of Solid Wastes (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur chemisch-thermischen Zersetzung von Halogenkohlenwasserstoffen in Inertgasatmosphäre, insbesondere von höher halogenierten Kohlenwasserstoffen, durch Reaktion mit einer überstöchiometrischen Menge alkalischer Festsubstanzen bei höheren Temperaturen in einem Reaktor.The invention relates to a process for the chemical-thermal decomposition of halogenated hydrocarbons in an inert gas atmosphere, in particular of higher halogenated hydrocarbons, by reaction with a stoichiometric amount of alkaline solid substances at elevated temperatures in a reactor.
Höher halogenierte Kohlenwasserstoffe werden in Industrie und Forschung sehr häufig einge- setzt. So dienen Fluorkohlenwasserstoffe als Treibgas und Kältemittel und sind Ausgangsstoffe zur Herstellung von chemisch sehr beständigen Kunststoffen. Chlorkohlenwasserstoffe werden in großen Mengen als Entfettungsmittel in metallverarbeitenden Betrieben eingesetzt. Weitere Anwendungsgebiete sind chemische Reinigungen aller Art. Darüberhinaus sind die Chlorkohlenwasserstoffe Ausgangsstoffe zur Herstellung von Polymeren, Pestiziden und Herbiziden. Insbesondere die polychlorierten Kohlenwasserstoffe wurden aufgrund ihrer hohen chemischen und thermischen Beständigkeit als Wärmeträgeröle oder Hydraulikflüssigkeiten eingesetzt. Die polychlorierten Biphenyle (PCB) sind typische Vertreter dieser Stoff klasse.Highly halogenated hydrocarbons are very often used in industry and research. For example, fluorocarbons serve as propellants and refrigerants and are the starting materials for the production of chemically very resistant plastics. Chlorinated hydrocarbons are used in large quantities as degreasing agents in metal processing plants. Further areas of application are chemical cleaning of all kinds. In addition, the chlorinated hydrocarbons are raw materials for the production of polymers, pesticides and herbicides. In particular, the polychlorinated hydrocarbons were used as heat transfer oils or hydraulic fluids due to their high chemical and thermal resistance. The polychlorinated biphenyls (PCB) are typical representatives of this class of substances.
Obwohl von der Möglichkeit der Rezyklierung gebrauchter Halogenkohlenwasserstoffe, soweit dies technisch möglich und wirtschaftlich vertretbar ist, Gebrauch gemacht wird, fallen allein in der Bundesrepublik Deutschland jährlich ca. 30 000 bis 40 000 t Chlorkohlenwasserstoffe mit Chlorgehalten > 20 % an, die entsorgt werden müssen.Although use is made of the possibility of recycling used halogenated hydrocarbons, insofar as this is technically possible and economically justifiable, approx. 30,000 to 40,000 t of chlorinated hydrocarbons with chlorine contents> 20% are generated in the Federal Republic of Germany alone, which have to be disposed of.
Bei diesen sogenannten Sonderabfällen handelt es sich neben Rückständen aus Rezyklierungsanlagen und Produktionsrückständen auch um Stoffe, deren Verwendung aus sicherheits- und umwelttechnischen Gesichtspunkten immer mehr eingeschränkt wird und die letztendlich einer Entsorgung zugeführt werden müssen. Das bekannteste Beispiel hierfür sind die polychlorierten Biphenyle, die in der Vergangenheit hauptsächlich als Trafoöle und als Dielektrika in Kondensatoren eingesetzt wurden. Allein durch Austausch dieser Flüssigkeiten gegen Ersatzstoffe rechnet man in der Bundesrepublik in den nächsten zehn Jahren mit jährlich ca. 6000 t zu entsorgenden polychlorierten Biphenylen.In addition to residues from recycling plants and production residues, these so-called special wastes are also substances whose use is being increasingly restricted from a safety and environmental point of view and which ultimately have to be disposed of. The best known example of this are the polychlorinated biphenyls, which in the past were mainly used as transformer oils and as dielectrics in capacitors. Simply by replacing these liquids with substitutes, the Federal Republic of Germany expects to dispose of around 6000 t of polychlorinated biphenyls annually over the next ten years.
Als Möglichkeit zur Entsorgung von Halogenkohlenwasserstoffen wird derzeit hauptsächlich die Verbrennung auf See angesehen. Internationale Abkommen (Osloer und Londoner Konvention) zielen jedoch darauf hin, die Verbrennung auf See bis Ende dieses Jahrzehnts gänzlich einzuschränken. Als Alternative dazu bleibt dann nur noch die Verbrennung an Land. Die Verbrennung von Halogenkohlenwasserstoffen, insbesondere fluorierten und höher chlorierten, in bestehenden Sonderabfallverbrennungsanlagen ist problematisch. Die wesentlichen Gründe für die Schwierigkeiten sind die Korrosionsgefahr für die Ausmauerung und die Abgasstrecke durch eine höhe Rohgasbeladung an Halogenwasserstoffen (HF und HCI), die Emissionssituation, insbesondere bei Verbrennung von fluorierten Kohlenwasserstoffen, und der hohe Einsatz an Energie.At present, incineration at sea is the main way of disposal of halogenated hydrocarbons. However, international agreements (the Oslo and London Conventions) aim to limit combustion at sea entirely by the end of this decade. The only alternative then is incineration on land. The combustion of halogenated hydrocarbons, especially fluorinated and more chlorinated ones, in existing hazardous waste incineration plants is problematic. The main reasons for the difficulties are the risk of corrosion for the brick lining and the exhaust gas section due to a high raw gas loading of hydrogen halide (HF and HCI), the emission situation, especially when burning fluorinated hydrocarbons, and the high use of energy.
Besonders durch den Umstand, daß bei unzureichenden Verbrennungsbedingungen bei der Chlorkohlenwasserstoff-Verbrennung hochgiftige polychlorierte Dibenzodioxine und Dibenzofurane gebildet werden können, ist diese Entsorgungspraxis zunehmender Kritik ausgesetzt.This disposal practice is subject to increasing criticism, in particular due to the fact that highly toxic polychlorinated dibenzodioxins and dibenzofurans can be formed in the case of insufficient combustion conditions during the chlorinated hydrocarbon combustion.
Ein Verfahren zur Oxidation von halogenierten Kohlenwasserstoffen, insbesondere von PCB, wird in « Destruction technologies for polychlorinated biphenyls, Economic and Technical Review, Report EPS 3-EC-83-1, Februar 1983, Seite 26-29, Ottawa •, abgehandelt.A process for the oxidation of halogenated hydrocarbons, in particular of PCB, is dealt with in “Destruction technologies for polychlorinated biphenyls, Economic and Technical Review, Report EPS 3-EC-83-1, February 1983, pages 26-29, Ottawa •.
Die Verbrennung erfolgt dabei in Drehrohröfen bei der Zementherstellung, d. h. in Anwesenheit von Calciumsilikaten und Aluminaten.The combustion takes place in rotary kilns during cement production, i.e. H. in the presence of calcium silicates and aluminates.
In der DE-OS 30 28 193 ist ein Verfahren zur pyrolytischen Zersetzung von Halogene und/oder Phosphor enthaltenden organischen Substanzen beschrieben, wobei diese mit Calciumoxid/Calciumhydroxid in einem überstöchiometrischen Verhältnis gemischt bei Temperaturen von 300 bis 800° C in einem Reaktor umgesetzt werden.DE-OS 30 28 193 describes a process for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances, which are reacted with calcium oxide / calcium hydroxide in a superstoichiometric ratio at temperatures of 300 to 800 ° C. in a reactor.
Nachteilig bei diesem Verfahren ist es, daß nicht alle Halogenkohlenwasserstoffe problemlos zersetzt werden können. Die notwendigen Temperaturen zur quantitativen Zersetzung der chemisch und thermisch sehr stabilen höher halogenierten Kohlenwasserstoffe, zu denen insbesondere die polychlorierten Biphenyle gezählt werden müssen, liegen über 600° C. Oberhalb dieser Temperatur bilden Mischungen aus CaO und Ca(OH)2 mit den entsprechenden Calciumchloriden Schmelzen. Diese Tatsache bereitet erhebliche Schwierigkeiten, da der notwendige kontinuierliche Feststoffdurchsatz durch den Reaktor dadurch behindert und unter Umständen sogar unmöglich wird. Neben den verfahrenstechnischen Schwierigkeiten führt die Bildung von Schmelzen gleichzeitig zu einer erheblichen Herabsetzung der Zersetzungsrate der halogenierten Kohlenwasserstoffe. Dies ist auf die starke Verringerung der Oberfläche der festen Reaktionspartner zurückzuführen, die bei Gas-Feststoffreaktionen einen wesentlichen Einfluß auf die Reaktion ausüben. Selbst ein starker Überschuß der genannten basischen Verbindungen vermag bei Temperaturen oberhalb 600° C eine Schmelzenbildung mit anschließender Verkrustung in der Abkühlphase nicht zu verhindern.The disadvantage of this process is that not all halogenated hydrocarbons can be easily decomposed. The temperatures required for the quantitative decomposition of the chemically and thermally very stable, more highly halogenated hydrocarbons, to which the polychlorinated biphenyls in particular must be counted, are above 600 ° C. Above this temperature, mixtures of CaO and Ca (OH) 2 form with the corresponding calcium chloride melts . This fact presents considerable difficulties since the necessary continuous throughput of solids through the reactor is thereby hindered and may even become impossible. In addition to the process engineering difficulties, the formation of melts also leads to a considerable reduction in the decomposition rate of the halogenated hydrocarbons. This is due to the large reduction in the surface area of the solid reactants, which have a significant influence on the reaction in gas-solid reactions. Even a strong excess of the basic compounds mentioned cannot prevent melting with subsequent incrustation in the cooling phase at temperatures above 600 ° C.
Es war daher Aufgabe der vorliegenden Erfindung, ein Verfahren zur chemisch-thermischen Zersetzung von Halogenkohlenwasserstoffen in Inertgasatmosphäre, insbesondere von höher halogenierten Kohlenwasserstoffen, durch Reaktion mit einer überstöchiometrischen Menge alkalischer Festsubstanzen bei höheren Temperaturen in einem Reaktor zu entwickeln, bei dem selbst bei Temperaturen über 1 000° C keine Verkrustungen der Restsubstanzen auftreten, das hinsichtlich der Temperaturführung unkritisch ist, hohe Dosierraten an halogenierten Kohlenwasserstoffen zuläßt und ein halogenfreies Abgas liefert.It was therefore an object of the present invention to develop a process for the chemical-thermal decomposition of halogenated hydrocarbons in an inert gas atmosphere, in particular of higher halogenated hydrocarbons, by reaction with a stoichiometric amount of alkaline solid substances at higher temperatures in a reactor in which itself at temperatures above 1,000 ° C there are no incrustations of the residual substances, which is not critical with regard to temperature control, allows high dosing rates of halogenated hydrocarbons and provides a halogen-free exhaust gas.
Diese Aufgabe wurde erfindungsgemäß dadurch gelöst, daß als alkalische Festsubstanzen Calcium- und/oder Magnesiumsilikate eingesetzt werden.This object has been achieved according to the invention in that calcium and / or magnesium silicates are used as alkaline solid substances.
Als Calciumsilikate bzw. Magnesium werden dabei vorzugsweise sog. Insel-Silikate, wie beispielsweise Ca2Si04, CasSi207 und Ca3Si309, Ketten-Silikate wie CaSi03, Bandsilikate wie Ca3Si4011, oder Netzsilikate wie CaSi205 eingesetzt. Diese Silikate können als natürlich vorkommende Mineralien wie z. B. Wollastonit oder Tobemorit verwendet oder synthetisch hergestellt werden. Bei der Herstellung ist aber darauf zu achten, daß die Schmelzpunkte der betreffenden Silikate nicht erreicht werden, um zu vermeiden, daß ein glasartig erstarrtes Produkt mit nur geringer Oberfläche und Porosität entsteht.So-called island silicates such as Ca 2 Si0 4 , Ca s Si 2 0 7 and Ca 3 Si 3 0 9 , chain silicates such as CaSi0 3 , band silicates such as Ca 3 Si 4 0 11 are preferably used as calcium silicates or magnesium , or network silicates such as CaSi 2 0 5 are used. These silicates can be found as naturally occurring minerals such as e.g. B. wollastonite or tobororite used or manufactured synthetically. During production, however, care must be taken to ensure that the melting points of the silicates in question are not reached, in order to avoid that a glass-like solidified product with only a small surface area and porosity is formed.
Es hat sich überraschenderweise gezeigt, daß beispielsweise Calciumsilikate bei Temperaturen von 400 bis 1 000° C mit Halogenkohlenwasserstoffen zu den entsprechenden Calciumhalogeniden und Siliziumdioxid umgesetzt werden, ohne daß es bei diesen Temperaturen zu Verbackungen oder Verkrustungen der Reaktionsprodukte kommt. Wie entsprechende Untersuchungen gezeigt haben, bleibt selbst bei quantitativer Umsetzung des im Silikat enthaltenen Calciums zu Calciumhalogenid das Si02-Skelett erhalten. Gleichzeitig wird gebildetes Calciumhalogenid im Si02-Gerüst fein verteilt, so daß es selbst bei 1 000° C zu keinen Verkrustungen kommt..It has surprisingly been found that, for example, calcium silicates are reacted with halogenated hydrocarbons at temperatures of 400 to 1,000 ° C. to give the corresponding calcium halides and silicon dioxide without caking or encrusting of the reaction products at these temperatures. As studies have shown, the Si02 skeleton is retained even when the calcium contained in the silicate is converted quantitatively to calcium halide. At the same time, calcium halide formed is finely distributed in the Si0 2 framework, so that there are no incrustations even at 1,000 ° C.
Da bei der Reaktion der Halogenkohlenwasserstoffe mit Calciumsilikat das Calcium aus dem Kristallgefüge herausgelöst wird, kommt es mit fortschreitender Reaktion, d. h. zunehmender Ausnutzung des festen Reaktionsproduktes, zu einem lockeren Gefüge, was gleichzeitig das Eindiffundieren der Halogenkohlenwasserstoffe in den Feststoff begünstigt. Dadurch reicht für die quantitative Umsetzung von Halogenkohlenwasserstoff mit Calciumsilikaten ein geringerer stöchiometrischer Überschuß an festem Reaktionspartner aus als bei Verwendung von Calciumoxid oder Calciumhydroxid.Since the reaction of the halogenated hydrocarbons with calcium silicate removes the calcium from the crystal structure, there is an ongoing reaction, i. H. increasing use of the solid reaction product to a loose structure, which at the same time favors the diffusion of the halogenated hydrocarbons into the solid. As a result, a smaller stoichiometric excess of solid reactant is sufficient for the quantitative reaction of halogenated hydrocarbon with calcium silicates than when using calcium oxide or calcium hydroxide.
Für die quantitative Umsetzung eines Halogenkohlenwasserstoffs genügt es, wenn das Calcium- bzw. Magnesiumsilikat, bezogen auf das abzubindende Halogen und unter Zugrundlegung der Bildung von Calciumhalogeniden, in einem 1,2- fachen stöchiometrischen Überschuß vorliegt. Vorzugsweise verwendet man einen ca. 1,5-fachen Überschuß.For the quantitative conversion of a halogenated hydrocarbon it is sufficient if the calcium or magnesium silicate is present in a 1.2-fold stoichiometric excess, based on the halogen to be set and on the basis of the formation of calcium halides. An approximately 1.5-fold excess is preferably used.
Anstatt Calciumsilikate können ebensogut Magnesiumsilikate eingesetzt werden, wobei ein Teil des Calciums oder Magnesiums im Silikat durch andere Metallkationen, wie beispielsweise Eisen, substituiert sein können.Instead of calcium silicates, magnesium silicates can equally well be used, it being possible for some of the calcium or magnesium in the silicate to be substituted by other metal cations, such as iron.
Darüber hinaus können auch synthetische Silikate oder Silikathydrate des Calciums oder Magnesiums eingesetzt werden, die freies überschüssiges Calciumoxid oder Magnesiumoxid enthalten.In addition, synthetic silicates or silicate hydrates of calcium or magnesium can be used, which contain free excess calcium oxide or magnesium oxide.
Die chemische Reaktion der Halogenkohlenwasserstoffe mit Silikaten ist weniger stark exotherm als die vergleichbare Reaktion mit Calciumoxid, so daß bei vergleichbaren Dosierraten eine geringere Temperaturerhöhung im Reaktor resultiert. Dies kann aus Gründen der Werkstoffwahl für den Reaktor von Bedeutung sein.The chemical reaction of the halogenated hydrocarbons with silicates is less exothermic than the comparable reaction with calcium oxide, so that a lower temperature increase in the reactor results at comparable metering rates. This can be important for the reactor because of the choice of material.
Die Umsetzung der Halogenkohlenwasserstoffe mit den Silikaten erfolgt in Anwesenheit von Inertgas vorzugsweise unter Normaldruck.The halogenated hydrocarbons are reacted with the silicates in the presence of inert gas, preferably under normal pressure.
Als sehr günstig hat sich die Verwendung von Silikaten in Form von Granulat bzw. in stückiger Form erwiesen. Die Herstellung solcher Granulate kann durch einen einfachen Pelletierprozeß erfolgen, wobei als Ausgangsstoffe handelsübliche Zemente oder auch gemahlene Zementrohklinker und Wasser eingesetzt werden können. Durch den Einsatz von Granulat läßt sich die Umsetzung in den unterschiedlichsten Reaktoren durchführen. So kann im einfachsten Fall eine Kartusche mit Granulat gefüllt werden, in die nach dem Aufheizen auf eine Reaktionstemperatur von 450-700° C der Halogenkohlenwasserstoff entweder flüssig oder gasförmig eindosiert wird. Die chemisch-thermische Zersetzung findet dann innerhalb der Schüttung statt, während das halogenfreie Abgas ungehindert durch das Granulatbett strömt und am anderen Ende der Kartusche austreten kann. Nach einer ca. 80-85 %-igen Ausnutzung der Granulatschüttung kann diese dann erneuert werden oder bei entsprechend preisgünstiger Gestaltung der Kartusche diese komplett ersetzt werden.The use of silicates in the form of granules or in lumpy form has proven to be very cheap. Such granules can be produced by a simple pelletizing process, using commercially available cements or ground cement raw clinker and water as starting materials. The use of granules enables the reaction to be carried out in a wide variety of reactors. In the simplest case, a cartridge can be filled with granules into which the halogenated hydrocarbon is metered in either liquid or gaseous after heating to a reaction temperature of 450-700 ° C. The chemical-thermal decomposition then takes place inside the bed, while the halogen-free exhaust gas flows unhindered through the granulate bed and can escape at the other end of the cartridge. After approximately 80-85% utilization of the granulate fill, it can then be renewed or, if the cartridge is designed accordingly, it can be completely replaced.
Vorzugsweise verwendet man als alkalische Festsubstanzen Zementklinker, Kalksandstein und/oder Gasbeton.Preferably, cement clinker, sand-lime brick and / or gas concrete is used as the alkaline solid substance.
Für eine kontinuierliche chemisch-thermische Zersetzung eines Halogenkohlenwasserstoffs mit Calciumsilikaten bietet sich ein Schachtofen an, der eine Schüttung an Calciumsilikat-Granulat enthält, die als Wanderbett ausgeführt ist, wobei der Halogenkohlenwasserstoff und entstehendes Abgas entweder im Gleichstrom oder im Gegenstrom durch die Schüttung strömt.For a continuous chemical-thermal decomposition of a halogenated hydrocarbon with calcium silicates, a shaft furnace is suitable, which contains a bed of calcium silicate granulate, which is designed as a moving bed, the halogenated hydrocarbon and the resulting exhaust gas flowing through the bed either in cocurrent or in countercurrent.
Als sehr vorteilhaft hat sich die Verwendung von künstlich hergestellten porösem Calciumsilikat in granulierter Form herausgestellt. Entsprechendes Granulat läßt sich beispielsweise durch Zerkleinern silikatreicher Baustoffe, wie Gasbetonsteinen oder Kalksandsteinen, herstellen. Diese Materialien sind mechanisch und thermisch ausreichend stabil, um als Schüttung in einem Wanderbettreaktor zu dienen und besitzt darüber hinaus eine sehr große Oberfläche. Dieses Material läßt sich bezogen auf den Ca-Gehalt nahezu stöchiometrisch mit den Halogenkohlenwasserstoffen umsetzen.The use of artificially produced porous calcium silicate in granulated form has proven to be very advantageous. Corresponding granules can be produced, for example, by crushing silicate-rich building materials, such as gas concrete blocks or sand-lime blocks. These materials are mechanically and thermally sufficiently stable to serve as a bed in a moving bed reactor and also have a very large surface area. This material can be converted almost stoichiometrically with the halogenated hydrocarbons based on the Ca content.
Die bei der chemisch-thermischen Zersetzung von Halogenkohlenwasserstoffen mit Silikaten entstehenden gasförmigen Reaktionsprodukte sind halogenfrei. Im Falle von nicht perhalogenierten Kohlenwasserstoffen enthält das Abgas entsprechende Mengen an Wasserstoff, Methan und eventuell andere teils gesättigte teils ungesättigte niedrige Kohlenwasserstoffe, sowie Kohlenmonoxid und Kohlendioxid. Das Abgas besitzt in diesem Fall noch einen erheblichen Heizwert und kann entsprechend genutzt werden oder auch einfach in einer Nachbrennkammer zu Kohlendioxid und Wasser nachverbrannt werden.The gaseous reaction products formed during the chemical-thermal decomposition of halogenated hydrocarbons with silicates are halogen-free. In the case of non-perhalogenated hydrocarbons, the exhaust gas contains corresponding amounts of hydrogen and methane and possibly other partly saturated partly unsaturated low hydrocarbons, as well as carbon monoxide and carbon dioxide. In this case, the exhaust gas still has a considerable calorific value and can be used accordingly or simply re-burned to carbon dioxide and water in an afterburning chamber.
Das erfindungsgemäße Verfahren zur chemisch-thermischen Zersetzung von höher halogenierten Kohlenwasserstoffen durch Reaktion mit Calcium- bzw. Magnesiumsilikaten ist ein umweltverträgliches und kostengünstiges Verfahren zur Entsorgung dieser Substanzen. Eine Bildung von Metaboliten, wie polychlorierten Dibenzodioxinen oder Furanen, wurde in keinem Fall beobachtet.The process according to the invention for the chemical-thermal decomposition of higher halogenated hydrocarbons by reaction with calcium or magnesium silicates is an environmentally friendly and inexpensive process for the disposal of these substances. No formation of metabolites such as polychlorinated dibenzodioxins or furans was observed.
Anhand der nachfolgenden Beispiele soll das erfindungsgemäße Verfahren zur chemisch-thermischen Zersetzung von Halogenkohlenwasserstoffen näher erläutert werden.The process according to the invention for the chemical-thermal decomposition of halogenated hydrocarbons is to be explained in more detail with reference to the examples below.
In ein Reaktionsrohr aus Aluminiumoxidkeramik werden ca. 250 g Gasbeton, der in granulierter Form mit einer Hauptkornfraktion von ca. 4 mm vorliegt, eingefüllt.About 250 g of gas concrete, which is in granular form with a main grain fraction of about 4 mm, are filled into a reaction tube made of aluminum oxide ceramic.
Das gefüllte Reaktionsrohr wird beidseitig verschlossen und senkrecht in einem Röhrenofen . fixiert und auf 700° C aufgeheizt. Über eine Kapillare werden anschließend innerhalb von 3 Stunden insgesamt 70 g polychlorierte Biphenyle (PCB) mit einem mittleren Chlorgehalt von 60 Gew. % von oben in das Reaktionsrohr eindosiert und gleichzeitig wird der Reaktor von oben nach unten mit auf 650° C vorgeheiztem Stickstoff bei Normaldruck durchströmt. Der Stickstoffvolumenstrom beträgt dabei ca. 5 bis 10 NI pro Stunde. Der Stickstoff tritt zusammen mit den gasförmigen Reaktionsprodukten am unteren Ende des Reaktors aus und wird durch eine Waschstrecke geleitet.The filled reaction tube is closed on both sides and vertically in a tube furnace. fixed and heated to 700 ° C. A total of 70 g of polychlorinated biphenyls (PCB) with an average chlorine content of 60% by weight are then metered into the reaction tube from above via a capillary within 3 hours, and at the same time the reactor is preheated from top to bottom with nitrogen preheated to 650 ° C. at normal pressure flows through. The nitrogen volume flow is about 5 to 10 NI per hour. The nitrogen escapes together with the gaseous reaction products at the lower end of the reactor and is passed through a washing section.
Zu Beginn der Umsetzung kommt es durch die exotherme Reaktion der PCB mit Ca-Silikat zu einem Temperaturanstieg in der Reaktionszone im oberen Teil der Schüttung. Im Laufe der Umsetzung wandert die ca. 820 bis 850° C heiße Reaktionszone nach unten, so daß anhand einer Temperaturmessung festgestellt werden kann, zu welchem Zeitpunkt die Kapazität der Schüttung erschöpft ist.At the beginning of the reaction, the exothermic reaction of the PCB with Ca silicate leads to a temperature increase in the reaction zone in the upper part of the bed. In the course of the reaction, the approximately 820 to 850 ° C. hot reaction zone migrates downward, so that a temperature measurement can be used to determine at what point in time the capacity of the bed is exhausted.
Die Zusammensetzung des als festen Reaktionspartner verwendeten Gasbetons wurde als Gemisch aus 58 Gew. % Ca3S!207. H20 und 42 Gew. % a-Quarz ermittelt.The composition of the gas concrete used as the solid reactant was determined as a mixture of 58% by weight Ca 3 S! 2 0 7 . H 2 0 and 42 wt.% A-quartz determined.
Die chemisch analytische Auswertung der Umsetzung erfolgte anhand der Rückstandsanalyse der Waschlösung und der Analyse des Feststoffrückstands. Bei einer Nachweisgrenze von 20 p.g PCB in der Waschlösung konnte kein PCB nachgewiesen werden, woraus sich ein Umsetzungsgrad von > 99,99996 % errechnet. Eine Bildung von Metaboliten, wie chlorierten Dibenzodioxinen oder Dibenzofuranen, findet bei der beschriebenen chemisch-thermischen Zersetzung von PCB nicht statt. Die genannten Verbindungen konnten bei einer Bestimmungsgrenze von 10 ng nicht nachgewiesen werden.The chemical analysis of the implementation was based on the residue analysis of the washing solution and the analysis of the solid residue. With a detection limit of 20 p.g PCB in the wash solution, no PCB could be detected, from which a degree of conversion of> 99.99996% is calculated. The chemical-thermal decomposition of PCBs does not result in the formation of metabolites, such as chlorinated dibenzodioxins or dibenzofurans. The compounds mentioned could not be detected at a limit of quantification of 10 ng.
Das Feststoffgranulat war auch nach der Reaktion rieselfähig und zeigte keinerlei Verbackungen. Die Hauptbestandteile waren Si02. und CaCl2. Daneben enthielt der feste Rückstand noch Reste von Calciumsilikat sowie geringe Mengen an elementarem Kohlenstoff. Das in Form von PCB in den Reaktor eindosierte Chlor wurde nach der chemisch-thermischen Zersetzung der PCB im Feststoffrückstand quantitativ als Chlorid wiedergefunden. Das Abgas war halogenfrei und enthielt neben Stickstoff im wesentlichen noch CO und H2.The solid granules were free-flowing even after the reaction and showed no caking. The main components were Si02. and CaCl 2 . In addition, the solid residue also contained calcium silicate and small amounts of elemental carbon. The chlorine metered into the reactor in the form of PCB was quantitatively recovered as chloride after the chemical-thermal decomposition of the PCB in the solid residue. The exhaust gas was halogen-free and essentially contained CO and H 2 in addition to nitrogen.
Analog Beispiel 1, wobei anstatt Gasbeton Zement verwendet wird. Um die Reaktion in einem Reaktionsrohr, wie in Beispiel 1 beschrieben, durchführen zu können, wurde aus dem Zementpulver ein poriges Granulat wie folgt hergestellt : 300 g Portlandzement werden mit 140 g Wasser angerührt. Nach einer Aushärtezeit von 24 h wird der Probekörper bei 600° C getrocknet, wobei nahezu das gesamte Anmachwasser aus dem Probekörper ausgetrieben wird. Der nach dem Trocknen und Abkühlen in kleine Stücke zerschlagene Zementkörper dient als Füllgut für das Reaktionsrohr.Analogous to Example 1, but cement is used instead of gas concrete. In order to be able to carry out the reaction in a reaction tube as described in Example 1, a porous granulate was produced from the cement powder as follows: 300 g of Portland cement are mixed with 140 g of water. After a curing time of 24 hours, the test specimen is dried at 600 ° C, almost all of the mixing water being expelled from the test specimen. The cement body, broken up into small pieces after drying and cooling, serves as filling material for the reaction tube.
Es wurden gleich gute Umsetzungsraten wie in Beispiel 1 erzielt. Der Feststoffrückstand zeigt keine Anbackungen und ist rieselfähig.The conversion rates were the same as in Example 1. The solid residue shows no caking and is free-flowing.
Analog Beispiel 2, wobei anstatt Portlandzement Zementrohklinker verwendet wird, ein Ausgangsprodukt der Zementherstellung.Analogous to Example 2, using cement raw clinker instead of Portland cement, a starting product of cement production.
Das Versuchsergebnis ist vergleichbar mit den in Beispiel 1 und 2 beschriebenen Ergebnissen.The test result is comparable to the results described in Examples 1 and 2.
Analog Beispiel 1, wobei anstatt Gasbeton ein synthetisch hergestelltes poriges Tricalciumsilikat in Granulatform eingesetzt wird. Die Herstellung des Produkts erfolgt wie nachfolgend beschrieben :Analogous to Example 1, but instead of gas concrete a synthetically produced porous tricalcium silicate in granulate form is used. The product is manufactured as described below:
168 g gebrannter Kalk werden mit 60 g Quarzsand gemischt und fein gemahlen. Anschließend wird die Mischung mit Wasser zu einer teigartigen Masse angerührt und mit 0,6 Aluminiumpulver vermischt. Innerhalb kurzer Zeit bläht sich die Masse auf. Die Probe wird dann in einem Autoklaven in Wasserdampfatmosphäre auf 200° C aufgeheizt. Es entsteht ein festes poriges Produkt, das in einem Backenbrecher zu einem Granulat mit einer mittleren Korngröße von ca. 5 mm gebrochen wird.168 g of burnt lime are mixed with 60 g of quartz sand and finely ground. Then the mixture is mixed with water to a dough-like mass and mixed with 0.6 aluminum powder. The mass swells up within a short time. The sample is then heated to 200 ° C. in an autoclave in a steam atmosphere. A solid pore is created Product that is broken into granules with an average grain size of approx. 5 mm in a jaw crusher.
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DE3940903A1 (en) * | 1989-12-11 | 1991-06-20 | Dinda Kickdown Gmbh | Toxic waste esp. halogenated organic and heavy metal disposal - by fixing with synthetic calcium hydro-silicate and opt. calcium aluminosilicate |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5276250A (en) * | 1986-07-11 | 1994-01-04 | Hagenmaier Hans Paul | Process for decomposing polyhalogenated compounds |
DE3623492A1 (en) * | 1986-07-11 | 1988-01-21 | Hagenmaier Hans Paul | METHOD FOR DEGRADING HALOGENATED AROMATES |
DE3632366C2 (en) * | 1986-09-24 | 1997-12-18 | Boelsing Friedrich | Process for the removal of halogenated hydrocarbons from the gas phase |
JPH066177B2 (en) * | 1987-01-13 | 1994-01-26 | 大豊産業株式会社 | Immobilization treatment agent for liquid organic halides using industrial waste, immobilization treatment method and combustion treatment method |
DE3918716C1 (en) * | 1989-06-08 | 1990-06-28 | Nukem Gmbh, 6450 Hanau, De | |
ATE104932T1 (en) * | 1990-08-31 | 1994-05-15 | Rheinische Kalksteinwerke | PROCESS FOR THE PRODUCTION OF CHLOROSILICATES. |
JPH0787867B2 (en) * | 1991-01-18 | 1995-09-27 | 日本碍子株式会社 | Organic chloride decomposition method |
US5776420A (en) * | 1991-07-29 | 1998-07-07 | Molten Metal Technology, Inc. | Apparatus for treating a gas formed from a waste in a molten metal bath |
US5191154A (en) * | 1991-07-29 | 1993-03-02 | Molten Metal Technology, Inc. | Method and system for controlling chemical reaction in a molten bath |
US5585532A (en) * | 1991-07-29 | 1996-12-17 | Molten Metal Technology, Inc. | Method for treating a gas formed from a waste in a molten metal bath |
US5260036A (en) * | 1992-02-27 | 1993-11-09 | Process Technologies, Inc. | Method and apparatus for use in photochemically oxidizing gaseous halogenated organic compounds |
US5397552A (en) * | 1992-02-27 | 1995-03-14 | Process Technologies, Inc. | Method and apparatus for use in photochemically oxidizing gaseous organic compounds |
AT402506B (en) * | 1993-01-26 | 1997-06-25 | Holderbank Financ Glarus | METHOD FOR THE PRODUCTION OF RAW IRON AND CEMENT CLINKER |
US5374337A (en) * | 1993-08-20 | 1994-12-20 | Technichem Engineering, Ltd. | Halohydrocarbon recovery process |
AU5575194A (en) * | 1993-11-29 | 1995-06-13 | Eimatsu Kanzaki | Detoxifying method for polychlorobiphenyl |
US5468459A (en) * | 1995-02-28 | 1995-11-21 | The Boc Group, Inc. | Gas stream treatment method for removing per-fluorocarbons |
US5705140A (en) * | 1995-07-18 | 1998-01-06 | Transformation Technologies, Ltd. | Process for the transformation of halogenated refrigerant gases |
US5601184A (en) * | 1995-09-29 | 1997-02-11 | Process Technologies, Inc. | Method and apparatus for use in photochemically oxidizing gaseous volatile or semi-volatile organic compounds |
US6888040B1 (en) * | 1996-06-28 | 2005-05-03 | Lam Research Corporation | Method and apparatus for abatement of reaction products from a vacuum processing chamber |
US6018091A (en) * | 1998-06-08 | 2000-01-25 | Quantum Marketing Corporation | Methods for thermally degrading unwanted substances using particular metal compositions |
USH2198H1 (en) | 2002-07-30 | 2007-08-07 | Ch2M Hill Inc. | Multi-stage pyrolysis systems for treating chlorine contaminated wastes |
EP1714690A4 (en) * | 2004-01-29 | 2009-08-05 | Taiyo Nippon Sanso Corp | Exhaust gas treating agent, method for treating exhaust gas and apparatus for treating exhaust gas |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3845191A (en) * | 1972-06-02 | 1974-10-29 | Du Pont | Method of removing halocarbons from gases |
US4022630A (en) * | 1972-07-27 | 1977-05-10 | The Associated Portland Cement Manufacturers Limited | Portland cement-making and municipal refuse conversion |
JPS4994578A (en) * | 1973-01-16 | 1974-09-07 | ||
US3864458A (en) * | 1973-06-11 | 1975-02-04 | Dorr Oliver Inc | Fluid bed incineration of chloride-containing waste streams |
US4001031A (en) * | 1973-11-16 | 1977-01-04 | Chem-Trol Pollution Services, Inc. | Process for making low alkali cement clinker |
GB1510392A (en) * | 1976-01-19 | 1978-05-10 | Ass Portland Cement | Portland cement manufacture and utilisation of waste matter |
US4301137A (en) * | 1977-12-21 | 1981-11-17 | Occidental Research Corporation | Removal of chlorine from pyrolysis vapors |
SE420646B (en) * | 1979-01-08 | 1981-10-19 | Cementa Ab | WAY TO DESTROY HEALTH AND ENVIRONMENTALLY WASTE AND YOUNG SYSTEM FOR IMPLEMENTATION OF THE KIT |
US4352332A (en) * | 1979-06-25 | 1982-10-05 | Energy Incorporated | Fluidized bed incineration of waste |
DE3004968A1 (en) * | 1980-02-11 | 1981-08-20 | Sante M Cundari | Fuel compsn. contg. iron oxide - in form of by=product waste obtd. in steel prodn. and a metallic reducer |
FR2480269A1 (en) * | 1980-04-09 | 1981-10-16 | Pichat Philippe | PROCESS FOR TREATING LIQUID WASTE OF HIGH ACIDITY |
DE3028193C2 (en) * | 1980-07-25 | 1984-11-22 | Nukem Gmbh, 6450 Hanau | Method and device for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances |
JPS5925335A (en) * | 1982-07-30 | 1984-02-09 | Kitamura Gokin Seisakusho:Kk | Method and apparatus for making pcb harmless |
DE3447337C2 (en) * | 1984-12-24 | 1986-11-06 | Nukem Gmbh, 6450 Hanau | Process for the chemical-thermal decomposition of higher halogenated hydrocarbons |
-
1985
- 1985-05-11 DE DE3517019A patent/DE3517019C2/en not_active Expired
-
1986
- 1986-03-29 EP EP86104351A patent/EP0204910B1/en not_active Expired
- 1986-03-29 AT AT86104351T patent/ATE35910T1/en not_active IP Right Cessation
- 1986-03-29 DE DE8686104351T patent/DE3660412D1/en not_active Expired
- 1986-05-09 ES ES554801A patent/ES8802119A1/en not_active Expired
- 1986-05-09 CA CA000508823A patent/CA1288441C/en not_active Expired - Fee Related
- 1986-05-12 JP JP61106893A patent/JPS61259683A/en active Granted
-
1988
- 1988-12-06 US US07/281,934 patent/US4937065A/en not_active Expired - Fee Related
Non-Patent Citations (2)
Title |
---|
Chem.-Ing.Tech. 56 (1984) Nr. 11, Seiten 819-829 * |
Müllverbrennung und Rauchgasreinigung. Aggregate und Systeme, Rückstände, Verfahrensbeurteilung, Schadstoffmessungen, K.J. Thomé-Kozmiensky, Berlin, E. Freitag, Verlag für Umwelttechnik, (1983), Seiten 1081-1087 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3940903A1 (en) * | 1989-12-11 | 1991-06-20 | Dinda Kickdown Gmbh | Toxic waste esp. halogenated organic and heavy metal disposal - by fixing with synthetic calcium hydro-silicate and opt. calcium aluminosilicate |
Also Published As
Publication number | Publication date |
---|---|
ES554801A0 (en) | 1988-04-01 |
DE3517019A1 (en) | 1986-11-13 |
US4937065A (en) | 1990-06-26 |
EP0204910A1 (en) | 1986-12-17 |
JPH0576313B2 (en) | 1993-10-22 |
DE3517019C2 (en) | 1987-03-26 |
ATE35910T1 (en) | 1988-08-15 |
JPS61259683A (en) | 1986-11-17 |
ES8802119A1 (en) | 1988-04-01 |
CA1288441C (en) | 1991-09-03 |
DE3660412D1 (en) | 1988-09-01 |
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