Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
  • C10L3/003—Additives for gaseous fuels
  • C10L3/006—Additives for gaseous fuels detectable by the senses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/10—Mixing gases with gases
  • B01F23/12—Mixing gases with gases with vaporisation of a liquid

Definitions

• the present invention relates to a method of adding a malodorant to a consumer gas which is distributed to a consumer station, so that persons present in the surroundings of the distribution system will be warned that the surroun ⁇ ding atmosphere contains more than the lowest permitted concentration of gas, therewith constituting the risk of explosion, suffocation, toxicity or some other risk.
• gases which can be odorized in this way is oxygen, which can cause extremely comprehensive fire and explosion damage if it leaks into the surroundings ambient of the distribution system and/or the consumer station and therewith enriches the ambient air or atmosphere.
• Another example includes combustible gases, such as natural gas, propane gas, town gas, etc., which when admixed with atmospheric oxygen can give rise to fires and explosions.
• Another example includes odorless, toxic gases or more or less inert gases. If these latter gases escape into the ambient surrounds, they are able to displace the oxygen in the air, thereby creating suffocation conditions.
• the Finnish Patent Application No. 870146 describes an improved method of adding a malodorant to oxygen gas so that if the air becomes enriched with oxygen, individuals in the near vicinity are warned that there is an imminent risk of explosion.
• This improved method eliminates the need of han ⁇ dling toxic malodorants by the consumer, thereby avoiding the risk of explosion created by the addition of such malodor ⁇ ants.
• a gaseous mixture of malodorant and a carrier gas in this case oxygen, a so-called master gas, by adding to the oxygen gas a malodorant in a concentration of 1,000- 10,000 ppm.
• the master gas is admixed with oxygen gas distributed to the consumer in an amount such that the malodorant has a concentration of 5-50 ppm in the consumer gas.
• the master gas contains solely oxygen and malodorant, for example dimethyl sulphide, DMS
• DMS dimethyl sulphide
• this application teaches a method of producing a master gas consisting of 0 oxygen and a malodorant, in this case dimethyl sulphide.
• the master gas container is first filled with a mixture of dimethyl sulphide and nitrogen or helium gas.
• the dimethyl sulphide is present in a concentration of 0.5-2.5 mole per cent.
• Oxygen gas is then 5 introduced until a desired working pressure, e.g. 200 bars, is obtained in the container.
• the object of the present invention is to provide a 0 method for producing master gas for admixture with a consumer gas, preferably natural gas and other combustible gases, such as town gas and propane gas, and oxygen, and which avoids the aforesaid drawbacks.
• a consumer gas preferably natural gas and other combustible gases, such as town gas and propane gas, and oxygen
• the method is characterized by dissolving a malodorant 5 in the form of an organic sulphur compound or a mixture of two or more organic sulphur compounds, said compounds comprising tetrahydrothiophene, methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, dimethyl sulphide, diethyl sulphide and methylethyl sulphide, in condensed carbon dioxide, sulphur hexafluoride or dinitrogen oxide in a pressure vessel, thereby obtaining in the pressure vessel a liquid phase, consisting of a solution of the malodorant in the condensed gas, and a gas phase; and by removing the liquid phase from the vessel, vaporizing said liquid phase and adding the vapor phase to the consumer gas distributed to the consumer.
• a malodorant 5 in the form of an organic sulphur compound or a mixture of two or more organic sulphur compounds, said
• the malodorant has a concentration of 0.5-10 mole per cent in the master gas. It is also preferred to add the master gas to the consumer gas in a quantity such that the malodorant concentration in said consumer gas is 1-20 ppm.
• the invention also relates to a gaseous mixture con ⁇ sisting of liquid carbon dioxide, sulphur hexafluoride or dinitrogen oxide containing a dissolved malodorant of the aforesaid kind.
• the malodorant which is an ill-smelling organic com- pound or a mixture of two or more such compounds, is intro ⁇ pokerd into the carrier gas, i.e. the condensed gas, as nitrous gas (laughing gas) , sulphur hexafluoride or prefera ⁇ bly carbon dioxide, in an amount of 0.5-10 mole per cent, calculated on the total quantity of gas.
• the carrier gas i.e. the condensed gas, as nitrous gas (laughing gas) , sulphur hexafluoride or prefera ⁇ bly carbon dioxide
• the aforesaid ill- smelling substances are soluble in the condensed gases in quantities suf ⁇ ficient to enable the method to be applied in practice.
• the pressure in the resultant gas phase will vary when the gas mixture is stored at differing temperatures.
• the malodorant content of the condensed gas is only affected to a negligible extent at temperatures within the range of -40°C to +50°C.
• Admixture of the master gas i.e.
• the carrier gas diluted with the malodorant, with the consumer gas is effected by first removing the liquid mixture of carrier gas and malodorant from the pressure vessel in which the mixture is stored, and vaporizing the liquid phase and then introduc- ing the gaseous mixture into the consumer gas in quantities such that the concentration of malodorant in the consumer gas will lie within the range of 1-50 ppm (1.0001-0.0050 mole per cent) , preferably within the range of 1-20 ppm.
• the master gas i.e.
• the gas mixture consisting of malodorant and carrier gas is to be admixed with a consumer gas which is distributed to various consumer stations through a pipe network or a through a central gas system, a gas mixer of more or less conventional kind is connected to the system upstream of the inlet to the pipe network.
• the consumer gas and the master gas are mixed in desired proportions in this mixer.
• the gas mixer includes a control system by means of which the ratio between the flow of master gas and the flow of consumer gas can be constantly maintained at a constant level. For example, if the master gas contains 2 mole per -cent malodorant and the consumer gas shall contain 4 ppm malodorant, the aforesaid ratio shall be 1:5000.
• the vaporized mixture When the consumer gas is distributed to the consumer in a high pressure container, the vaporized mixture, the master gas, is first introduced into the container in a quantity such that the desired proportion of malodorant is obtained when subsequently introducing the consumer gas into the container to the desired container pressure.
• the consumer gas containing the malodorant added thereto in accordance with the invention will therefore contain a given amount of carrier gas in addition to the malodorant.
• the carrier-gas content of the master gas is, for instance, 95 mole per cent, i.e. the master gas contains 5 mole per cent malodorant, an admixture has been effected with one part of master gas to 5000 parts of consumer gas, the malodorant content will be 10 ppm and the carrier gas content, e.g. carbon dioxide, will be 0.02 mole per cent.
• This proportion of non-combustible carrier gas is insig ⁇ nificant with regard to combustible gases.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Treating Waste Gases (AREA)
• Disinfection, Sterilisation Or Deodorisation Of Air (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Detergent Compositions (AREA)
• Gas Separation By Absorption (AREA)

Priority Applications (12)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20378412

Family Applications (1)

Country Status (12)

Cited By (5)

Families Citing this family (1)

Citations (4)

Family Cites Families (4)

• 1990
  • 1990-05-22 DE DE69019378T patent/DE69019378T2/de not_active Expired - Fee Related
  • 1990-05-22 BR BR909008026A patent/BR9008026A/pt not_active IP Right Cessation
  • 1990-05-22 DK DK90910956.3T patent/DK0533670T3/da active
  • 1990-05-22 JP JP90510062A patent/JPH05507022A/ja active Pending
  • 1990-05-22 WO PCT/SE1990/000340 patent/WO1991017817A1/en active IP Right Grant
  • 1990-05-22 AU AU60305/90A patent/AU650849B2/en not_active Ceased
  • 1990-05-22 ES ES90910956T patent/ES2072441T3/es not_active Expired - Lifetime
  • 1990-05-22 EP EP90910956A patent/EP0533670B1/de not_active Expired - Lifetime
• 1992
  • 1992-11-19 NO NO924460A patent/NO177456C/no unknown
  • 1992-11-20 LT LTIP183A patent/LT3095B/lt not_active IP Right Cessation
  • 1992-11-20 RU RU9292016382A patent/RU2041920C1/ru active
  • 1992-12-01 LV LVP-92-242A patent/LV10212B/en unknown

Patent Citations (4)

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