+

WO1996030084A1 - Procede de destruction d'halocarbures - Google Patents

Procede de destruction d'halocarbures Download PDF

Info

Publication number
WO1996030084A1
WO1996030084A1 PCT/GB1996/000684 GB9600684W WO9630084A1 WO 1996030084 A1 WO1996030084 A1 WO 1996030084A1 GB 9600684 W GB9600684 W GB 9600684W WO 9630084 A1 WO9630084 A1 WO 9630084A1
Authority
WO
WIPO (PCT)
Prior art keywords
sodium
halocarbon
reaction
halocarbons
contacting
Prior art date
Application number
PCT/GB1996/000684
Other languages
English (en)
Inventor
Maurice Raymond Hillis
David Alan Gardner
David James Ambrose
Original Assignee
Ea Technology Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ea Technology Limited filed Critical Ea Technology Limited
Priority to AU51513/96A priority Critical patent/AU5151396A/en
Publication of WO1996030084A1 publication Critical patent/WO1996030084A1/fr

Links

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
    • A62D3/30—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
    • A62D3/32—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents by treatment in molten chemical reagent, e.g. salts or metals
    • 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
    • A62D3/36—Detoxification by using acid or alkaline reagents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/68—Halogens or halogen compounds
    • B01D53/70—Organic halogen compounds
    • 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

Definitions

  • This invention relates to a process for the destruction of halocarbons.
  • halocarbons halogenated hydrocarbons
  • bromo-trifluoro methane which is commonly known as Halon 1301
  • Halon 1301 is used as a fire extinguisher agent.
  • it has a very high ozone depletion potential and is a powerful greenhouse gas.
  • Halon 1301 can be reacted with molten sodium to convert it into carbon, sodium fluoride and sodium bromide by the following reaction:-
  • reaction with molten sodium is very exothermic and complex in that the gaseous halocarbon reacts with the liquid sodium to produce solids.
  • the exothermic nature of the reaction means that unless the mixture is kept well stirred, hot spots with sparking and glowing can develop. Furthermore, the reaction mixture becomes sticky and very viscous as more and more solid products build up and the mixture tends to bind into a solid mass.
  • the reaction is much more controllable. Hot spots, sparking and glowing do not develop and the temperature in the reactor can easily be controlled by limiting the flow of halocarbon gas entering the reactor.
  • the reactor can be jacketed and a cooling medium circulated through the jacket to control the reaction temperature.
  • reaction mixture remains free flowing and easily stirrable throughout the reaction.
  • low-power motors can be used or a fluidised bed system can be employed.
  • very high utilisations of sodium can be achieved particularly, as the Applicants have discovered, if the process is carried out under pressure. As the reaction is mass transfer limited, the increased pressure generates greater driving force and therefore maintains a high overall reaction rate.
  • the supported sodium is in thin layers and therefore there is no opportunity for thick product layers to form that could inhibit the reaction.
  • a process for the destruction of halocarbons which process comprises supporting metallic sodium at a temperature above its melting point on a solid, preferably non-porous, particulate carrier material and contacting the halocarbon or halocarbons in a gaseous state with the supported sodium to react the halocarbon or halocarbons with the sodium to form elemental carbon and sodium halide or halides.
  • the process of the present invention can be applied to any halocarbon which exists in, or can be brought into, the vapour state for contact with the supported sodium in accordance with the method of this invention.
  • the invention has particular applicability to halons, CFCs (chlorofluorocarbons) , HCFCs (hydrochlorofluoro- carbons) , HFCs (hydrofluorocarbons) and halogenated solvents.
  • halocarbons are those which have given particular concern from an environmental point of view.
  • the sodium metal used in the method of the invention is at a temperature above its melting point. It is preferred that the sodium is held at a temperature in the range from 98°C to 500°C, and more preferably at a temperature in the range of 98°C to 300°C, and preferably above 200°C.
  • the solid particulate carrier material is preferably non-porous and may, for example, be silica, alumina, sand, glass beads, carbon, salts or any other similar solid materials in a finely divided form.
  • the particle size is below 500 ⁇ m .
  • Sand has been found to be a particularly useful carrier material being relatively inexpensive and freely available.
  • other support materials may have particular usefulness for certain applications, for example carbon, this of course being one of the products of the chemical reaction which forms the basis of the process.
  • the halocarbon will usually be passed in gaseous form into a reactor vessel containing the supported molten sodium. If the halocarbon is in liquid form it will be vaporised before being passed into the reactor vessel .
  • the molten sodium may be dispersed on a heated solid support material in a preparation vessel preferably under a blanket of inert gas such as nitrogen, the supported molten sodium being then passed into the main reactor vessel where it is contacted with the gaseous halocarbon.
  • the sodium may be dispersed on the heated solid particulate support material under a blanket of inert gas in the same reactor as that in which the halocarbon destruction is subsequently to be carried out.
  • the halocarbon in gaseous or vaporised form may be admitted to a reactor which is filled with inert gas and which contains the supported molten sodium.
  • the reactor may have a fixed bed of supported sodium it is usually preferred that the particulate support material with sodium supported thereon is kept in motion, e.g. by stirring or by use of a fluidised bed technique, this having the advantage that reaction products are not permitted to combine into a continuous phase and therefore cause the bed to solidify.
  • the amount of sodium dispersed on the particulate support material prior to the halocarbon destruction reaction is from 1 to 50 weight percent, and more preferably from 5 to 15 weight percent.
  • the temperature of the supported sodium may be controlled by controlling the rate at which halocarbon is admitted to the reaction chamber and/or by use of a cooling jacket placed around the reactor. It is necessary, from time to time, to remove the solid products of the reaction, namely carbon and sodium halides, from the reactor. This can be done in a semi-batch mode by removing a proportion of the solid material at the end of a halocarbon reaction phase and quenching it in water or alcohol to remove any residual sodium. The sodium halides can be dissolved away and the carbon removed. The particulate base support material can then be removed, dried and then re-used. An equivalent amount of support material may be added each time solid product and support material is removed from the reactor. The products can then be worked up for value.
  • bromine can be recovered from aqueous sodium bromide by passing in chlorine gas.
  • An operation in semi-batch manner can also involve dispersing further sodium on the support material in the reactor vessel when the majority of the sodium has been consumed in a first batch.
  • further supported sodium can be added from a sodium preparation vessel to the reactor vessel and the halocarbon destruction reaction repeated.
  • some of the solid material i.e. particulate support material and products
  • the process can be operated in a continuous manner in which supported sodium is continuously fed from a sodium preparation vessel into the main reactor vessel at such a rate that the sodium is largely consumed by the time the solid materials (i.e. the particulate support material together with solid products) flow out of the reactor vessel.
  • solid materials may be withdrawn from the reactor and thereafter quenched in water or an alcohol to remove any residual sodium and to dissolve sodium halides, the particulate support material being then treated as desired and returned for re-use in the process.
  • a factor which has been found to be important in the operation of the method of the present invention has been the pressure at which the process is performed. Bearing in mind that the reaction between molten sodium and gaseous halocarbons tends to be very vigorous and exothermic it is perhaps surprising that any suggestion should be made that the reaction be carried out at a pressure greater than atmospheric pressure.
  • the Applicants have found that by carrying out the method of the invention above atmospheric pressure, or by causing or allowing the pressure to increase above atmospheric pressure as the reaction proceeds, has an effect that the reaction proceeds more completely and that little or no sodium remains in the solid mixture after reaction which has to be disposed of as described above by reaction with water or alcohol.
  • the increase in pressure should have this desirable effect but, as mentioned hereinbefore, it is conjectured as the reaction is mass transfer limited, the increased pressure generates greater driving force and therefore maintains a high overall reaction rate.
  • the increase in pressure over atmospheric pressure is at least Bar absolute.
  • the reactor as shown diagrammatically in Figure 1 consists of a 500 ml reaction flask complete with flange head with several inlets into the reactor.
  • One inlet is for the stirrer, another inlet is a combined thermocouple and gas delivery point for the direct introduction of nitrogen and halon into the support.
  • Another inlet is used for charging sand and sodium to the reactor, and one is used for the gas exit stream from the reactor to the wash bottle.
  • the agitation was set and maintained at 125 rpm through the course of the experiment. At 60 sees, into the reaction an exotherm had been observed and the support temperature had risen from 203°C to 214°C. This exotherm continued and the support temperature rose steadily until it peaked after 14 mins. at a temperature of 287°C. The temperature of the support then fell steadily. After 30 mins. and at a temperature of 224°C the halon flow to the bed was stopped. The reaction was deemed complete and the vessel was allowed to cool to room temperature under nitrogen.
  • the sample contained 0.54 g of unreacted sodium. Therefore the total unreacted sodium remaining on the support was 2.19 g.
  • the sodium added at the start of reaction was 10.45 g. Therefore 8.26 g of sodium reacted with 13.53 g of halon 1301.
  • the reactor consists of a 500 ml reaction flask complete with flange head with several inlets into the reactor.
  • One inlet is for the stirrer, another inlet is a combined thermocouple and gas delivery point for the direct introduction of nitrogen and halon into the support.
  • Another inlet is used for charging sand and sodium to the reactor, and one is used for the gas exit stream from the reactor to the recirculating pump, which recirculates the gas to the gas inlet port.
  • the particulate support for this experiment consisted of 170.6 g from the support used in Example 1, which remained after the 55.98 g sample was removed for analysis. In addition 57.45 g of fresh pre-dried sand was added, giving a total support weight of 228.05 g. There was 1.65 g of unreacted sodium remaining on the support from the 170.6 g portion used from Example 1.
  • This support of 228.05 g was added to the vessel and heated under a nitrogen purge and gentle agitation to 200°C. When the support had attained this temperature, a charge of 11.99 g of sodium was added to the support through the inlet. The support was maintained at 200°C while the sodium charge was allowed to disperse evenly over the support, at 100 rpm. After 10 mins. when an even dispersion had been achieved the nitrogen flow and heating mantle were shut off in preparation for the halon introduction. The pressure in the reactor at this stage is 1 atm. (absolute) of nitrogen and any pressures referred to hereinafter are gauge pressures. The regulator on the halon 1301 cylinder was set at 0.5 Bar and the recirculating pump connected to seal the reactor system.
  • the stirrer was set at 100 rpm and the halon flowrate set at approx. 250 cc/min.
  • a drop in temperature reading was observed. This was due to the pressure created from the pump displacing the support from around the thermocouple. Therefore it was a few minutes before equilibrium was established and the temperature rise due to the exotherm truly recorded.
  • the temperature of the support was 190°C and the pressure in the reactor had risen to 0.2 Bar.
  • the temperature of the support was 197°C and the pressure in the reactor had risen to 0.3 Bar. The support continued to rise steadily in temperature and pressure until at 27 mins.
  • a 58.24 g sample was taken for analysis.
  • the sample contained 0.23 g of unreacted sodium.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Business, Economics & Management (AREA)
  • Toxicology (AREA)
  • General Health & Medical Sciences (AREA)
  • Emergency Management (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Ce procédé de destruction d'halocarbures consiste à placer du sodium métallique, à une température supérieure au point de fusion de celui-ci, sur un matériau-support à base de matières particulaires solides et à mettre en contact l'halocarbure ou les halocarbures à l'état gazeux avec le sodium sur support afin de le (les) faire réagir avec celui-ci en vue d'obtenir du carbone élémentaire et un ou des halogénures de sodium.
PCT/GB1996/000684 1995-03-24 1996-03-22 Procede de destruction d'halocarbures WO1996030084A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU51513/96A AU5151396A (en) 1995-03-24 1996-03-22 Process for the destruction of halocarbons

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9506067A GB2299080A (en) 1995-03-24 1995-03-24 Process for the destruction of halocarbons
GB9506067.9 1995-03-24

Publications (1)

Publication Number Publication Date
WO1996030084A1 true WO1996030084A1 (fr) 1996-10-03

Family

ID=10771848

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1996/000684 WO1996030084A1 (fr) 1995-03-24 1996-03-22 Procede de destruction d'halocarbures

Country Status (3)

Country Link
AU (1) AU5151396A (fr)
GB (1) GB2299080A (fr)
WO (1) WO1996030084A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9525894D0 (en) * 1995-12-19 1996-02-21 Univ Manchester Destruction of halocarbons
US11512013B2 (en) * 2019-09-18 2022-11-29 Ralph Birchard Lloyd System and method of reducing oxidants in a chemical stream

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4639309A (en) * 1985-09-18 1987-01-27 Hydro-Quebec Process for the dehalogenation of polyhalogenated hydrocarbon containing fluids
EP0467053A1 (fr) * 1990-07-16 1992-01-22 Degussa Aktiengesellschaft Procédé de déshalogénation de composés organiques par des métaux alcalins sur des supports solides
WO1994003237A1 (fr) * 1992-08-06 1994-02-17 Ea Technology Limited Procede de destruction d'halocarbones
EP0595079A1 (fr) * 1992-10-28 1994-05-04 Degussa Aktiengesellschaft Procédé de réaction des CFC's avec les dispersions de métaux alcalins

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4639309A (en) * 1985-09-18 1987-01-27 Hydro-Quebec Process for the dehalogenation of polyhalogenated hydrocarbon containing fluids
EP0467053A1 (fr) * 1990-07-16 1992-01-22 Degussa Aktiengesellschaft Procédé de déshalogénation de composés organiques par des métaux alcalins sur des supports solides
WO1994003237A1 (fr) * 1992-08-06 1994-02-17 Ea Technology Limited Procede de destruction d'halocarbones
EP0595079A1 (fr) * 1992-10-28 1994-05-04 Degussa Aktiengesellschaft Procédé de réaction des CFC's avec les dispersions de métaux alcalins

Also Published As

Publication number Publication date
AU5151396A (en) 1996-10-16
GB9506067D0 (en) 1995-05-10
GB2299080A (en) 1996-09-25

Similar Documents

Publication Publication Date Title
US5198122A (en) Method of detoxification of substances by utilization of ultrasonic energy
JP5562638B2 (ja) 高圧触媒活性化法及びそれにより製造された触媒
US5416247A (en) Chemical disposal of halocarbons
US5108647A (en) Method of dehalogenating halogenated hydrocarbons
JP3553934B2 (ja) 失活触媒を再生するための改良法
KR100384274B1 (ko) 불소 화합물 분해용 반응제, 분해방법 그의 용도
Nagasaki et al. Study on a novel catalytic reaction and its mechanism for CF3I synthesis
WO1996030084A1 (fr) Procede de destruction d'halocarbures
JP2000159505A (ja) フッ素化ハロゲン化合物の製造方法
WO1995018652A1 (fr) Procede de production de dispersions de sodium et de mise en reaction d'organohalogenures
US5318228A (en) Sodium dispersion and organohalide reaction processes
JP4785532B2 (ja) ハイドロフルオロカーボンの製造方法、その製品およびその用途
JP2918542B1 (ja) 有機ハロゲン化合物の処理方法
EP1373173B1 (fr) Purification d'halocarbones satures
CN117101689A (zh) 用于六氟丙烷制备的催化剂、六氟丙烷及其制备方法
CA2201164C (fr) Regeneration des catalyseurs de fluoration en phase gazeuse
JP3976332B1 (ja) 高濃度有機塩素化合物の分解方法
CN1285583C (zh) 六氟环氧丙烷的制备方法
JP2681034B2 (ja) フロンの無害化方法
RU2170701C2 (ru) Способ получения фторированного углерода
JPH09122442A (ja) ハロゲン化物ガスの分解方法
JPH06205853A (ja) フッ素及び塩素を含有する炭化水素とアルカリ金属との反応方法
JP4938931B2 (ja) 難分解性ハロゲン化合物の分解処理方法
JPH05239107A (ja) ゴム材料を低分子量の有機成分に崩壊する方法
JP2533596B2 (ja) 過酸化水素の製造法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU FI JP NO NZ US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载