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 OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • 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

Definitions

• the present invention relates to the use of mixtures containing alkyl acrylates and / or alkyl methacrylates and acyclic or cyclic ketones for the odorization of natural gas, a process for the odorization of natural gas and natural gas containing these mixtures.
• Gas odorization is the addition of odor-intensive substances (odorants) that act as warning or alarm substances to otherwise odorless gases.
• Natural gas mainly consists of methane (typical methane contents are in the range of 50 to 99% by weight, mostly in the range of 60 to 90% by weight) and, depending on its origin, can also contain different proportions of ethane, propane and higher molecular weight hydrocarbons.
• DNGW German Gas and Water Association
• shock odorization up to three times the amount of odorant is added to the gas compared to conventional odorization. Shock odorization is used, for example, when commissioning new networks or line sections to quickly reach the minimum odorant concentration or to detect small leaks in the gas installation.
• THT and mercaptans are ideal for reliable gas odorization.
• the combustion of gases odorized in this way produces sulfur oxides as combustion products - several hundred tons per year nationwide.
• JP-B-51-007481 mentions that acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate and butyl acrylate are known to have weak odorization properties for fuel gases and are of practically no significance in this regard.
• the document describes and claims allyl acrylate as an effective odorant.
• JP-A-55-104393 describes that odorant containing an alkyne and at least 2 compounds selected from a group consisting of methyl acrylate, ethyl acrylate, methymethacrylate, allyl methacrylate, ethyl propionate, methyl n-butyrate, Methyl iso-butyrate and prenyl acrylate, and optionally tert-butyl mercaptan, are suitable for the odorization of fuel gases.
• DE-A 19837066 addresses the problem of sulfur-free gas odorization using mixtures comprising at least one and a nitrogen compound having a boiling point in the range of 90 to 210 ° C and one
• the present invention relates to the use of mixtures comprising at least one acrylic acid CrC ⁇ alkyl ester or at least one methacrylic acid C 1 -C 6 alkyl ester, at least one compound of the formula (I)
• X is an alkyl group having 1 to 3 carbon atoms or an alkenyl group
• Y is hydrogen, an alkyl group having 1 to 5 carbon atoms or one
• A represents hydrogen, methyl, ethyl, methoxy, acetoxy
• Z is hydrogen, an alkyl group having 1 to 5 carbon atoms or one
• X and Z together form a 5- to 8-membered carbon ring which optionally has a further double bond and / or at most another 2 substituents from the group methoxy, methyl or ethyl,
• Methane content of at least 60% by weight.
• Another object of the present invention is a process for the odorization of fuel gases with a methane content of at least 60% by weight with the mixtures according to the invention.
• Another object of the present invention are fuel gases with a
• Methane content of at least 60% by weight containing the mixtures according to the invention Methane content of at least 60% by weight containing the mixtures according to the invention.
• the mixtures (odorants) according to the invention are excellent alternatives to known sulfur-free odorants.
• alkyl or alkenyl groups mentioned can be methyl, ethyl,
• the compounds of the formula (I) contain double bonds, they can be in the respective (E) or (Z) form or as a mixture of the double bond isomers.
• X represents methyl or ethyl
• Y is hydrogen, an alkyl group having 1 to 3 carbon atoms or one
• A represents hydrogen, methyl, methoxy, acetoxy;
• Z represents hydrogen, an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms;
• X and Z together form a total of 5 to 6-membered carbon ring which optionally has a further double bond and / or at most one further substituent from the group methoxy, methyl or ethyl.
• the compounds of formula (I) preferred according to the invention are liquid at 25 ° C. and 1013 mbar. These liquids can also be highly viscous or oily.
• Particularly advantageous compounds of the formula (I) are cycloalkenones and correspond to the formula (Ia):
• m 0 or 1.
• Particularly advantageous compounds are also acyclic ketones and correspond to the formula (Ib):
• X represents methyl or ethyl
• Y represents hydrogen, an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 or 3 carbon atoms;
• Z represents hydrogen, an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms;
• the acrylic acid-CrC 6 -alkyl esters are advantageously selected from the group consisting of acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid n-propyl ester,
• C 1 -C 4 acrylic acid esters in particular methyl acrylate
• Very particularly preferred acrylic acid C] -C 4 -alkyl esters are acrylic acid methyl ester, acrylic acid ethyl ester and acrylic acid n-butyl ester.
• the methacrylic acid alkyl ester-dC ö advantageously be chosen from the group comprising methyl methacrylate, ethyl methacrylate, methacrylic acid-n-propyl ester, methacrylic acid iso-propyl ester, methacrylic acid n-butyl ester, methacrylic acid isobutyl ester, methacrylic acid tert-butyl ester, methacrylic acid n-pentyl ester, methacrylic acid isopentyl ester and methacrylic acid n-hexyl ester.
• C 1 -C 4 alkyl methacrylic acid in particular methyl methacrylic acid, ethyl methacrylic acid, n-propyl methacrylic acid, isopropyl methacrylic acid, n-butyl methacrylic acid and isobutyl methacrylic acid.
• Very particularly preferred methacrylic acid-CrC-alkyl esters are methyl methacrylate and methyl methacrylate.
• Preferred odorants contain at least 2 or at least 3 acrylic acid alkyl esters, at least 2 or at least 3 methacrylic acid alkyl esters or at least one acrylic acid alkyl ester and at least one methacrylic acid alkyl ester.
• Particularly preferred odorants contain at least 2 or at least 3 acrylic acid alkyl esters.
• the acrylic mixtures contain the low molecular weight
• Acrylic acid alkyl ester and the higher molecular weight acrylic acid alkyl ester preferably in a weight ratio of 9: 1 to 1: 9, preferably from 7: 3 to 3: 7.
• the odorant contains at least two acrylic-C 1 -C 4 -alkyl esters next to one another, very preferably methyl acrylate and
• the compounds of the formula (I) can be used in the mixtures according to the invention in amounts of 1 to 100, preferably 10 to 100, in particular 20 to 50 parts by weight per 1000 parts by weight of C 1 -C 6 -alkyl and / or methacrylic acid.
• antioxidants can be added, for example, to the stability of the odorant according to the invention.
• examples include vitamin C and derivatives (eg ascorbyl palmitate, ascorbyl acetate), tocopherpole and derivatives (eg vitamin E, vitamin E acetate), vitamin A and derivatives (Vitamin A - palmitate) phenolic benzylamines, formic acid, acetic acid, benzoic acid, sorbic acid, hexamethylenetetramine, tert.-butylhydroxytoluene, tert.-butylhydroxyanisole, c-hydroxy acids (e.g. citric acid, lactic acid, malic acid), hydroquinone monomethyl ether.
• Preferred antioxidants are tert-butylhydroxytoluene (BHT, Jonol), tert-butylhydroxyanisole, hydroquinone monomethyl ether and ⁇ -tocopherol.
• the odorants advantageously contain one, two or three antioxidants, preferably one or two antioxidants.
• the antioxidants are preferably used in amounts of 0.01 to 5, in particular 0.05 to 2, especially 0.1 to 1 part by weight per 1000 parts by weight of acrylic acid alkyl ester and / or methacrylic acid ester.
• the total amount of antioxidants in the odorant is usually in the range 0.001-1% by weight, preferably in the range 0.01-0.5% by weight, particularly preferably in the range 0.05-0.25% by weight.
• the amount of odorant based on the gas to be odorized is typically in the range 5-100 mg / m 3 , preferably 5-50 mg / m 3 , particularly preferably 10-40 mg / m 3 and very particularly preferably 12-30 mg / m 3rd
• Me-Ac methyl acrylate; Et-Ac: ethyl acrylate; Bu-Ac: n-butyl acrylate; Me-Me: methyl methacrylate; Et-Me: ethyl methacrylate; Bu-Me: n-butyl methacrylate; BHT: tert-butylated hydroxytoluene; BHA: tert-butylated hydroxyanisole; Hydr: hydroquinone monomethyl ether
• the odorants according to the invention were evaluated in terms of their odor and their warning intensity against unodorized natural gas (blank value) in concentrations of 10, 25 and 50 mg / m 3 natural gas (methane content: 85% by weight).
• Odorized natural gas which contained the same concentrations of THT or a mixture according to JP-B-51-034841 (60% by weight of ethyl acrylate, 20% by weight of n-valeric acid and 20% by weight of triethylamine) was used as a reference. ,
• the experiment was carried out at room temperature (about 20 ° C.) in such a way that the odorant was metered into a gas stream in a tube. At the end of this 2 m long tube (homogenization takes place inside the tube), the exiting odorized gas is assessed by a group of trained examiners (8 to 12 people). The evaluation was carried out on a scale from 1 (very weak / very little warning) to 10 (very strong / very warning), the values given are mean values. The industrial standard THT was given the value 10.
• Table 1 shows references and mixtures according to the invention in comparison.
• Table 2 shows the evaluations for cyclic ketones of the formula (Ia), which were carried out as described in Example 1.
• Table 3 shows the evaluations for acyclic ketones of the formula (Ib), which were carried out as described in Example 1. ,
• Table 4 shows odorants according to the invention with acrylates containing antioxidants.
• Table 5 shows odorants according to the invention with methacrylates containing antioxidants. Table 5:
• Table 6 shows odorants according to the invention containing mixtures of compounds of the formula (I) according to the invention and antioxidants. 16 -
• Table 7 shows odorants according to the invention with acrylates and methacrylates containing 0.1 parts by weight of antioxidants (BHT or BHA).

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Liquid Carbonaceous Fuels (AREA)

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• 2002
  • 2002-08-05 DE DE10235750A patent/DE10235750A1/de not_active Withdrawn
• 2003
  • 2003-08-02 EP EP03784160A patent/EP1529092B1/fr not_active Expired - Lifetime
  • 2003-08-02 AU AU2003255361A patent/AU2003255361A1/en not_active Abandoned
  • 2003-08-02 AT AT03784160T patent/ATE366297T1/de not_active IP Right Cessation
  • 2003-08-02 DE DE50307624T patent/DE50307624D1/de not_active Expired - Lifetime
  • 2003-08-02 WO PCT/EP2003/008594 patent/WO2004015037A1/fr not_active Ceased

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