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

Definitions

• the present invention relates to the use of an acrylic acid alkyl ester containing a small proportion of a sulfur-containing compound and a further component for the odorization of fuel gas, a process for the odorization of fuel gas and fuel gas containing this mixture.
• Gas odorization means the addition of odor-intensive substances (odorants) that act as warning or alarm substances to gases that do not have a significant intrinsic odor, ie to gases that are otherwise essentially or completely odorless.
• Natural gas mainly consists of methane (typical methane contents are in the
• the odorant must not only smell unpleasant and unmistakable, but above all must clearly represent a warning smell. Therefore, the smell of the odorized gas must not be familiar to people from everyday life, e.g. from the kitchen and household. In Germany about 90% of the process gas is currently odorized with tetrahydrothiophene (THT) (12 - 25 mg / m 3 ); in addition, odorization with mercaptans is also common.
• THT tetrahydrothiophene
• 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 new networks or line sections are put into operation to quickly reach the minimum odorant concentration or to detect small leaks in the gas installation.
• THT THT alone is ideal for reliable gas odorization.
• the gases odorized in this way burn to a greater extent
• Sulfur oxides are produced as combustion products.
• 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 odor component.
• 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, methyl methacrylate, allyl methacrylate, ethyl propionate, methyl n-butyrate, methyl isobutyrate and prenyl acrylate , and optionally tert-butyl mercaptan, are suitable for the odorization of fuel gases.
• the amount of odorant is 50 ppm by weight (mg / kg gas), preferably greater than or equal to 100 ppm.
• LPG liquefied petroleum gas
• a better odor effect was achieved by adding 2-butyne (50 ppm) to a mixture of methyl acrylate (50 ppm), allyl acrylate (100 ppm) and TBM (5 ppm).
• the best result showed a mixture of 2-butyne (50 ppm), allyl methacrylic lat (20 ppm), methyl acrylate (20 ppm), methyl n-butyrate (20 ppm), methyl isobutyrate (20 ppm), ethyl propionate (20 ppm) and TBM (5 ppm).
• JP-B-51-034841 found "odor threshold values" of various substances, n-valeric acid, n-butyric acid, isobutyraldehyde and various methylamines having low odor "odor threshold values”.
• the optimized mixture comprised 50-90% by weight of ethyl acrylate, 10-50% by weight of n-valeric acid and optionally triethylamine.
• the optimized mixture comprised ethyl acrylate, n-valeric acid and triethylamine, this mixture containing equal parts by weight of n-valeric acid and triethylamine and 30 to 80% by weight of ethyl acrylate.
• a mixture consisting of 60% by weight of ethyl acrylate and 20% by weight of n-valeric acid and triethylamine was added to a gaseous fuel gas at 10 mg / m 3 .
• Odorants for fuel gases consisting of ethyl acrylate (70% by weight) and tert-butyl mercaptan (30% by weight) are known from JP-B 51-021402. This mixture was added to a gaseous fuel gas in an amount of 5 mg / m 3 .
• Odorants for the odorization of heating gases consisting of a) 30-70% by weight of CrC-alkyl mercaptans, b) 10-30% by weight of n-valeraldehyde and / or isovaleralaldehyde, n-butyric acid and / or isobutyric acid and optionally c ) up to 60 wt .-% tetrahydrothiophene are described in DE-A 31 51 215. These odorants were added to heating gas in amounts of 5-40 mg / m 3 .
• LPG was obtained at 40 mg / kg with a mixture of equal parts of 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene or at 50 mg / kg with a mixture of 80% by weight of 5-ethylidene-2 norbornene and 20% by weight of ethyl acrylate.
• DE-A 19837066 solved the problem of sulfur-free gas odorization by means of mixtures comprising at least one C 1 -C 2 -alkyl acrylate and a nitrogen compound with a boiling point in the range from 90 to 210 ° C. and a molecular weight from 80 to 160, mixtures containing at least two various acrylic acid alkyl esters are preferred.
• Alkyl-substituted 1,4-pyrazines are described as particularly suitable nitrogen compounds.
• antioxidants especially phenol derivatives, to stabilize
• Mercaptan-containing or alkyl acrylate-containing gas odorants are suitable, is known from US-A 2,430,050 and DE-A 19837066.
• the present invention relates to the use of a mixture containing
• the invention also relates to a corresponding process for the odorization of fuel gases with a methane content of at least 60% by weight with mixtures to be used according to the invention.
• a mixture to be used according to the invention is added to the fuel gas.
• Another object of the present invention are fuel gases with a methane content of at least 60% by weight containing the mixtures to be used according to the invention.
• the fuel gas to be odorized has a methane content of at least 60% by weight, preferably at least 70% by weight and particularly preferably at least 75% by weight.
• the acrylic acid CrC 6 alkyl esters are advantageously selected from the group comprising acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid n-propyl ester, acrylic acid isopropyl ester, acrylic acid n-butyl ester, acrylic acid isobutyl ester, acrylic acid tert-butyl ester, acrylic acid n-pentyl ester, acrylic acid iso-pentyl ester and acrylic acid n-hexyl ester.
• CrC 4 -alkyl acrylates in particular methyl acrylates, ethyl acrylates, n-propyl acrylates, isopropyl acrylates, n-butyl acrylates and isobutyl acrylate are preferred.
• Very particularly preferred acrylic acid CrC 4 alkyl esters are acrylic acid methyl ester, acrylic acid ethyl ester and acrylic acid n-butyl ester.
• the preferred weight ratio of low molecular weight acrylic acid alkyl ester to higher molecular weight acrylic acid alkyl ester is in the range 9: 1 - 1: 9, preferably in the range 7 : 3 - 3: 7, in particular in the range 3: 1 - 1: 4.
• the weight ratio of low molecular weight acrylic acid alkyl ester to higher molecular weight acrylic acid alkyl ester is very particularly preferably in the range 1: 1 - 1: 3.
• the compounds from group A) are advantageously contained in the mixtures to be used according to the invention to 60-97% by weight, preferably to 70-95% by weight and particularly preferably to 80-95% by weight.
• the mercaptans can be, for example, ethyl mercaptan, n-
• the thiophenes are advantageously thiophenes which are substituted by 1 to 4, preferably by one or two, dC 4 alkyl and / or alkoxy groups.
• the thiophenes can also be hydrogenated thiophenes, with tetrahydrothiophene being preferred.
• the sulfides can be, for example, dimethyl sulfide, diethyl sulfide, di-n-propyl sulfide, diisopropyl sulfide, di-n-butyl sulfide, diisobutyl sulfide, ethyl methyl sulfide, methyl n-propyl sulfide, methyl isopropyl sulfide, methyl isobutyl sulfide, ethyl isopropyl sulfide, or ethyl isopropyl sulfide.
• Dimethyl sulfide, diethyl sulfide, di-n-propyl sulfide, diisopropyl sulfide, di-n-butyl sulfide and diisobutyl sulfide are preferred.
• the disulphides can be, for example, dimethyl disulphide, diethyl disulphide, di-n-propyl disulphide, diisopropyl disulphide, di-n-butyl disulphide, diisobutyl disulphide, ethyl methyl disulphide, methyl n-propyl disulphide, methyl isopropyl disulphide, methyl disulphyl disulphyl disulphyl disulphide or disulfide act.
• Dimethyl disulfide, diethyl disulfide, di-n-propyl disulfide, diisopropyl disulfide, di-n-butyl disulfide and diisobutyl disulfide are preferred.
• the compounds from group B) in the mixtures to be used according to the invention are typically 1-30% by weight, advantageously 2-25% by weight, preferably 3-15% by weight, and particularly preferably 5-10
• the norbornenes are advantageously those with a molecular weight of less than or equal to 130, preference is given to norbornene, 2,5-norbornadiene, 5-ethylidene-2-norbornene and 5-vinylI-2-norbornene.
• the carboxylic acids are advantageously acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, n-caproic acid, isocaproic acid or 2-methylvaleric acid.
• the aldehydes are advantageously acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, n-capronaldehyde, isocapronaldehyde or 2-methylvaleraldehyde.
• the phenols are advantageously substituted phenols with a total of one or two dC 4 alkyl and / or CC 4 alkoxy groups.
• Preferred phenols are 3-methylphenol, 2-ethylphenol, 4-ethylphenol, 2-isopropylphenol, 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2- Methoxyphenol, 2-methoxy-4-methylphenol and 2-methyl-5-isopropylphenol.
• C 1 -C 4 -monoalkylated phenols are particularly preferred.
• anisoles are anisole, 2-methylanisole, 4-allylanisole or 4-methylanisole.
• the pyrazines are advantageously alkylated and / or acylated pyrazines.
• advantageous pyrazines are 2-methylpyrazine, 2-ethylpyrazine, 2,3-dimethylpyrazine, 2,3-diethylpyrazine, 2,6-dimethylpyrazine, 2,3-methylethylpyrazine, 5,2-methylethylpyrazine, 2,3,5-trimethylpyrazine, 3,5,2-dimethylethylpyrazine, 3,6,2-dimethylethylpyrazine, 5,2,3-methyldiethylpyrazine, tetramethylpyrazine, 2,3-methylacetylpyrazine or 2-acetylpyrazine.
• Preferred are pyrazines with a total of one to three, particularly preferably with a total of one or two, dC 4 alkyl and / or C 1 -C 8 acyl groups.
• the acylated pyrazines are preferably monoacylated and particularly preferably have an acetyl or propionyl group, preference being given to monoacetylated pyrazines, in particular 2-acetylpyrazine.
• the compounds from group C) are typically contained in the mixtures to be used according to the invention to 0.5-20% by weight, advantageously to 1-10% by weight, preferably to 1-5% by weight.
• the odorant to be used according to the invention can, for example, have antioxidants used as component D) to increase stability.
• antioxidants used as component D) to increase stability.
• examples include vitamin C and derivatives (e.g. ascorbyl palmitate, ascorbyl acetate), tocopherols and derivatives (e.g. vitamin E, vitamin E acetate), vitamin A and derivatives (vitamin A palmitate) phenolic benzylamines, formic acid, acetic acid, benzoic acid, sorbic acid, Hexamethylenetetramine, tert-butylated hydroxytoluene, tert.-butylated hydroxyanisole, ⁇ -hydroxy acids (eg citric acid, lactic acid, malic acid), hydroquinone monomethyl ether.
• Preferred antioxidants are tert-butyl hy- droxytoluene (BHT, Jonol), tert-butylated hydroxyanisole and hydroquinone mono
• antioxidants in particular ensures a high storage stability of the mixtures to be used according to the invention, as well as of the odorized ones
• the odorants advantageously contain one, two or three antioxidants, and one or two antioxidants are preferred.
• the total amount of antioxidants (component D) in the odorant is usually in the range 0.01-2% by weight, preferably in the range 0.02-1% by weight, particularly preferably in the range 0.03-0.6% by weight. -%.
• the amount of odorant based on the fuel 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
• the warning smell of a natural gas odorized according to the invention was from a
• mixtures comprising is preferred according to the invention A) at least two different acrylic acid CrC ⁇ alkyl esters;
• R 1 is hydrogen, methyl or ethyl, preferably methyl
• R 2 represents an alkyl group with 1 to 4 carbon atoms, preferably methyl, ethyl, iso-propyl, iso-butyl or tert-butyl;
• Preferred components B) are the mercaptans of the formula (I).
• the most preferred group C) compound is isovaleric acid
• the most preferred group D) antioxidants are hydroquinone monomethyl ether and tert-butylated hydroxytoluene.
• MeAc methyl acrylate
• EtAc ethyl acrylate
• TBM tert-butyl mercaptan
• IVS isovaleric acid
• BHT tert-butylated hydroxytoluene.
• Components A), B) and C) odorants to be used according to the invention became odorless as individual substances in concentrations of 10, 25 and 50 mg / m 3 natural gas (natural gas L; methane content: approx. 85% by volume) with regard to their warning - Odor and their warning intensity against unodorized natural gas (blank value). These concentrations correspond to the typical concentrations of odorant in natural gas under normal conditions or with shock odorization. Odorized natural gas containing the same concentrations of THT 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.
• the escaping 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 THT and components A), B) or C) to be used according to the invention as individual substances (ie not in the form of the mixture to be used according to the invention) in comparison.
• Table 4 shows that the use of mixtures of components A), B) and C) brings about excellent odorization performance.
• the amount of odorant added to the natural gas was 20 mg / m 3 .
• the odorant consisted of 60% EtAc minus y% antioxidant, 31% MeAc, 7% TBM, 2% IVS and y% antioxidant. Table 5 shows the results in comparison.

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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)
• Disinfection, Sterilisation Or Deodorisation Of Air (AREA)
• Treating Waste Gases (AREA)
• Industrial Gases (AREA)
• Liquid Carbonaceous Fuels (AREA)

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• 2003
  • 2003-12-19 DE DE10359743A patent/DE10359743A1/de not_active Withdrawn
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  • 2004-12-01 WO PCT/EP2004/053202 patent/WO2005061680A1/fr active Application Filing
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