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
• • 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

• the present invention relates to a method for the destruction of halogen-containing, environmental harmful substances such as a halogen- carbon substance or dhlorenated organic substances, by converting said substances to substances that are not considered to be environmentally harmful.
• the Swedish Patent Specification Nos. 7706876-5, 8103201-3, 8301159-3 and 8503571-5 teach processes for converting carbon to carbon gas, converting iron ore to crude iron or combinations thereof, these processes being characterized by introducing appropriate reactants into a bath of molten iron and causing the reactants to react at a temperature of 1400-1500°C, at which the reaction rate is high and conversion takes place quickly and with a high degree of conversion.
• the present invention is based on the understanding of the reaction conditions which exist, for instance, in the process described in Swedish Patent Specification No. 8301159-3, i.e. the reaction between organic material, such as coal (carbon), peat, etc.
• the iron bath is used to transfer heat, to dissolve a given part of the material introduced thereto, and to form salts, wherein a primary object of the invention is to destruct organic, environmentally harmful substances which are introduced into the iron bath to this end.
• the inventive method enables environmentally harmful material to be destructed highly effectively and at relatively low costs, the resultant end products being unharmful to the environment and capable of being handled in a conventional manner.
• the invention thus relates to a method for the destruction of a halogen-containing substance, such as a halocarbon substance or a chlorenated organic substance, by converting the substance to an environmentally harmless state.
• the method is particularly characterized by causing the halogen- containing substance to react with molten iron and to form an iron salt or iron salts, by introducing said substance into the bath together with oxygen gas and/or an oxygen-containing material, and by causing the iron salt/salts to leave the bath in the form of a dust and gas flow.
• the system of apparatus illustrated in the drawing includes a reactor vessel 1, an iron bath 2, an outlet aperture 3, and injection nozzles 4.
• the nozzles 4 are mounted in the bottom of the reactor vessel 1 and function to inject oxygen gas 5 or the like, additional fuel 6, such as coal 6, and a halogen-containing substance or substances 7 into the molten bath.
• the reference numeral 8 identifies reaction zones which extend up through the bath, while the reference numeral 9 identifies liquid slag on the surface of the bath.
• the oxygen gas 5 forms an oxidant for oxidizing of the carbon contained in the substance or substances to be destroyed.
• the oxidant may consist of same other oxygen- containing material, such as iron ore, or combinations of oxygen gas and some other oxygen-containing material. It is often preferred to introduce oxygen gas and/or oxygen-containing material into the bath in substantially stoichicroetric quantities in relation to the total amount of carbon introduced to the bath, this carbon being in the form of the carbon contained by the substance or substances delivered to the bath.
• Supplementary fuel 6 is supplied when there is a need for additional energy.
• the fuel 6 may consist of for instance coal in powder form and/or hydrocarbons, such as propane.
• halogens in the halogen-containing substance react with iron in the iron bath to form iron halides, which can be dumped or converted to acids with, for instance, water in a later process stage and the acids handled in a conventional manner. Halogens in this state are no longer considered to be harmful to the environment.
• Halocarbons often include chlorine (Cl), fluorine (F) or bromine (Br) in addition to carbon (C).
• Cl chlorine
• F fluorine
• Br bromine
• Iron salts and gas are formed when the halocarbons come into contact with an iron bath which is heated to a temperature of 1500°C.
• the salts farmed are primarily FeCl 2 , FeBr 2 and FeF 3 .
• the iron salts leave the iron bath 2 in a flow 10 of dust and gas.
• the reaction products leave the iron bath and are cooled and separated, the products transform from a condensed state to a solid, particulate state.
• Table 2 The state of the compounds at different temperature are set forth in Table 2 below.
• oxygen gas and/or an oxygen-containing material is delivered to the dust and gas flow 10.
• Another method is to gasify an appropriate fuel in the process, for instance powdered carbon, such as to supply energy. Same types of coal powder will, at the same time, release hydrogen gas which reacts with the halogens to form HBr, HCl and HF. More generally, the hydroge halides can be farmed by introducing hydrogen gas and/or hydrogen- containing material to the iron bath and/or to said dust and gas flow.
• the illustrated system of apparatus includes a first gas conduit 11 through which the flew of dust and gas passes from the reactor 1 to a first wet so called scrubber 12, in which the gas/dust suspension is cooled and the dust extracted, and a second gas conduit 13 through which the dust and gas flow passes from the first scrubber 12 to a second wet scrubber 14, in which the suspension is cooled and dust extracted therefrom.
• Liquid, primarily water, draining from the first scrubber 12 is collected in a separator 15, such as a lamellar separator 15, where particles are extracted from the liquid, and a settling device 16, such as a settling tank positioned downstream of the separator.
• Liquid which drains from the second scrubber 14 is conducted to a cor ⁇ ditioning apparatus 17 which includes a tank in which the pH of the liquid is adjusted, in the illustrated case with sodium hydroxide, NaOH, before passing the liquid to the settling tank 16, to which calcium hydroxide Ca(OH) 2 may also be supplied.
• a cor ⁇ ditioning apparatus 17 which includes a tank in which the pH of the liquid is adjusted, in the illustrated case with sodium hydroxide, NaOH, before passing the liquid to the settling tank 16, to which calcium hydroxide Ca(OH) 2 may also be supplied.
• Clean gas is removed from the second wet scrubber 14 and, in accordance with the illustrated example, passes to a droplet separator 18 and a measuring station 19.
• halogen-contaiiiing material halon 1301
• a 10-tonne iron bath contained in a reactor vessel, together with 75 m 3 n oxygen.
• oxygen gas was introduced in stoichiometric quantities through nozzles mounted in the reactor wall. Gasification of the carbon in the iron bath takes place through partial combustion of the carbon added, therewith forming carbon monoxide.
• the material introduced had a short residence time in the bath ( ⁇ 1s), but was efffectively degraded due to the extremely good heat transfer achieved and due to the high average bath temperature, 1500°C (local temperature 2000-2300°C).
• This process thus provides very good conditions for degrading or breaking-down organic material effectively and homogenously.
• the inventive method will be understood essentially from the aforegoing.
• the halogen-containing, environmentally harmful material concerned is converted to iron salt or iron salts in a high-temperatur iron bath having good heat transfer properties, whereafter the iron salt or salts leaving the bath are treated conventionally and released to atmosphere, recovered or dumped, said salt or salts being harmless to the environment.
• halogen-containing, environmentally harmful waste can be handled very effectively and relatively simply by means of the inventive method.
• the flow of dust and gas can be subsequently treated in a manner different to that illustrated in Figure 1.
• the halogen-containing substance can be introduced into the iron bath by injecting the substance beneath the surface of the bath and/or by injecting the substance from above down onto the bath surface.
• environmentally harmful substances present in the gas and dust flow are oxidized by delivering oxygen gas and/or oxygen-containing material to said flow.
• the dust and gas flew is heated in an afterburner zone so as to ensure that no environmentally harmful substances remain after destruction.
• the dust and gas flow is preferably heated by means of an oxygen-gas/gasol, plasma or the like.
• Destruction can take place at atmospheric pressure or at a pressure above atmospheric.
• the dust and gas flew is passed through a dry or a wet/dry gas cleaning process, where calcium compounds are used to absorb hydrogen halides.
• a dry or a wet/dry gas cleaning process where calcium compounds are used to absorb hydrogen halides.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=20377588

Family Applications (1)

Country Status (3)

Cited By (17)

Citations (3)

• 1989
  • 1989-11-24 SE SE8903972A patent/SE467483B/sv not_active IP Right Cessation
• 1990
  • 1990-11-21 EP EP19900917609 patent/EP0502063A1/en not_active Withdrawn
  • 1990-11-21 WO PCT/SE1990/000754 patent/WO1991008023A1/en not_active Application Discontinuation

Patent Citations (3)

Also Published As

Similar Documents

Legal Events