KR100933493B1 - The compositions of sulfur free odorant - Google Patents

Abstract

PURPOSE: A composition for sulfur free odorant is provided to prevent metal corrosion of the odorant with chemical stability, and to produce the composition having small exhaust gas such as sulfurous acid gas etc. CONSTITUTION: A composition for sulfur free odorant includes one or more selected from (C1~C5)alkyl isovalerate in a chemical formula 1, one or more selected from an acrylate-based compound in a chemical formula 2, and one or more selected from a nitrogenous compound in a chemical formula 3. One or more selected form the compound of the chemical formula 2 is used in a weight ratio of 3~7 : 7~3 with one or more selected from the (C1~C5)alkyl isovalerate. One or more selected from the nitrogenous compound is used in the weight ratio of 1 : 0.01 ~ 0.5 with the one or more selected from the (C1~C5)alkyl isovalerate.

Description

Non-sulfur based odorant composition {The Compositions of Sulfur Free Odorant}

The present invention relates to a non-sulfur-based odorant contained in fuel gas such as liquefied petroleum gas, natural gas, city gas or methane gas, propane gas, butane gas, dimethyl ether-liquefied petroleum gas or fuel gas such as hydrogen gas. will be. More specifically, parts based on alkyl isovalate, an ester-based organic compound, alkyl acrylate, and an acrylic organic compound, alkyl pyrazine, which is excellent in chemical stability, hardly corrosive to metals, and contain no sulfur. It relates to a composition of the blowing agent.

Regulations on sulfur in transportation fuels are being strengthened all over the world, and the legal quality of transportation fuels such as domestic gasoline, diesel and liquefied petroleum gas (Liquefied Petroleum Gas, LPG) has been recently strengthened due to the expansion and expansion of eco-friendly fuels and renewable energy. Sulfur content in the baseline also tends to be low sulfur or sulfur free (less than 10 mg / kg).

Fuel gases such as liquefied petroleum gas, city gas, industrial gas, or natural gas have a low odor, so they cannot be detected even if they leak, and there is a risk of causing a fire, explosion, or poisoning. These fuel gases contain odorants to easily detect leaks in the human sense of smell and to prevent accidents.

Currently added odorants are organic sulfur compounds containing sulfur components, which are classified into three groups: mercaptan, cyclic sulfide, and alkyl sulfide. The mercaptans used internationally include ethyl mercaptan, tert-butyl mercaptan, n-propyl mercaptan and sec-butylmercaptan. Cyclosulfides include tetrahydrothiophene and sulfides such as dimethylsulfide and methylethylsulfide. One or two or more of these substances are mixed and added to the fuel gas.

The ultimate purpose of the odorant is to ensure the stability of use and the following conditions should be provided.

First, there should be no harm and no toxicity to the human body.

Second, it must be mixed uniformly with the fuel gas.

Third, the volatility must be high with respect to fuel gas.

Fourth, it should be clearly distinguished from the odor that can be felt in general, and should have a distinctive smell that stinks as a gas smell even if various smells are mixed.

Fifth, olfactory fatigue should be able to recover quickly.

Sixth, the chemical stability should be high and low corrosiveness.

Seventh, after combustion completely, there should be no harmful or odorous substances after combustion.

Eighth, it is insoluble in water and should have low freezing point and boiling point.

Ninth, the permeability to the soil should be good.

Tenth, there should be a detection method other than sensuality.

Eleventh, it must be cheap and easy to supply.

In Korea, the regulations on odorous petroleum are regulated in the "Safety and Business Management Act of Liquefied Petroleum Gas" and "City Gas Business Act" to mix odorants that can be detected in the air with a ratio of 1 to 1000 It is stipulated that there will be regulations and devices for this. Thus, the odorants used in Korea are sulfur-based, ethyl mercaptan, vigilleak 7030 (dimethyl sulfide (70%) and tert-butyl mercaptan (30%)) and CP 630 (methyl ethyl sulfide (5%). , Dimethyl sulfide (3%), tert-butyl acaptan (13%), n-pentane (1%) and n-hexane (76%)) are used. Quality control at mg / kg. It is also used as a mixture of tetrahydrothiophene (70%) and tert-butylmercaptan (30%) in natural gas.

In Japan, on the other hand, when the container is filled with liquefied petroleum gas to the High Pressure Gas Security Act and Article 9 of the liquefied petroleum gas security rule, a substance that can be detected in the state of air in gas in a thousandth of a state is added. It is supposed to be. The odorant used in natural gas is used by adding a mixture of dimethylsulfide and tert-butyl mercaptan.

In Europe, ethyl mercaptan (70%), which is slightly different from one country to another but is currently inexpensive and functional, is used, and tetrahydrothiophene and ethyl mercaptan are used. The mixture of) is used.

Although sulfur-based odorants are added to fuel gas and are widely used, sulfur, which is absolutely derived from odorants, which are sulfur compounds, is discharged into sulfur dioxide as sulfur dioxide, causing air pollution. In particular, domestic liquefied petroleum gas is sulfur-free or low-sulfur, but the sulfur content is managed high due to the influence of sulfur-based odorant injected for the purpose of use stability. The high sulfur content of liquefied petroleum gas is known as one of the main causes of metal corrosion of fuel system. In addition, new devices using liquefied petroleum gas, such as fuel cells, have been developed. However, when using a sulfur-containing odorant, there is a problem that the odorant must be removed. In accordance with the regulations on emission gas (sulphite gas) in transportation fuels, which are strengthened around the world, and the spread of eco-friendly fuels, there is a need for desulfurization of odorants artificially introduced into liquefied petroleum gas.

As a non-sulfur odorant for fuel gas, U.S. Patent No. 7,108,803 discloses a mixture of acrylic acid and a nitrogen compound, but there is a problem in residualness when used as a fuel gas for transportation. Aldehydes, ketones, etc. have a problem of chemical instability during long-term storage.

In order to solve the problems of the prior art, the present invention has excellent chemical stability as a non-sulfur based odorant, has almost no metal corrosiveness, and does not contain sulfur, so that the exhaust gas such as sulfurous acid gas when burned as a fuel gas is used. It is an object to provide a composition of less clean non-sulfur based odorants.

The present invention provides a non-sulfur-based moiety comprising at least one compound selected from alkyl isovalate, which is an ester organic compound, and alkyl acrylate or alkyl pyrazine, which is an acrylic organic compound, in order to achieve the above technical problem. It provides a blowing composition. The non-sulfur based odorant composition according to the present invention uses a mixture of at least one compound selected from alkyl acrylate or alkyl pyrazine with alkyl isovalate, which significantly improves odor strength and odor than when used alone. Fatigue recovers quickly. In addition, the non-sulfur based odorant composition according to the present invention has a much superior effect in terms of odor strength and odor in comparison with the non-sulfur based odorant which is conventionally composed of two compounds of alkyl acrylate and alkyl pyrazine.

Hereinafter, the present invention will be described in more detail.

The non-sulfur based odorant composition according to the present invention is specifically at least one (A) selected from isobalate-based compounds of formula (1) and at least one (B) selected from acrylate-based compounds of formula (2) or At least one selected from the nitrogen-containing compound represented by the following formula (C) or a mixture thereof, and may further contain an antioxidant.

[Formula 1]

[Formula 2]

[Formula 3]

In Formula 1 to Formula 2, R ¹ and R ² are independently selected from linear or branched (C ₁ -C ₅ ) alkyl, more preferably R ¹ and R ² are independently selected from methyl, ethyl or propyl. Is selected.

In addition, in Formula 3, R ³ to R ⁶ are independently hydrogen, or selected from linear or branched (C ₁ ~ C ₄ ) alkyl.

Examples of the compound of Formula 1 include methyl isovalate, ethyl isovalate, and propyl isovalate. Examples of the compound of Formula 2 include methyl acrylate, ethyl acrylate, and propyl acrylate. .

One or more (B) selected from the compound of Formula 2 is used in the range of weight ratio (A: B) 3-7: 7-3 with respect to one or more (A) selected from the compound of Formula 1. This is preferable because, when mixed in the above range, the odor strength and the odor as the odorant is higher than in the case out of the above range, and the olfactory fatigue is quickly recovered.

At least one (C) selected from the nitrogen-containing compound of Formula 3 is preferably 1: 0.01 to 0.5 in weight ratio (A: C) with respect to at least one (A) selected from the compound of Formula 1, This is mixed in the weight ratio for the chemical stability and odor strength and odor of the formula (2), when mixed in a weight ratio (A: C) 1: 0.5 or more may increase the residual fuel gas may cause problems in the fuel system is not preferred not.

At least one selected from the nitrogen-containing compound of Formula 3 (C) is 2-ethyl-3-methyl pyrazine, 2,6-dimethyl pyrazine, 2-methyl pyrazine, 2-ethyl pyrazine, 2,3-dimethyl pyrazine, 2,3-diethyl pyrazine, 2,6-diethyl pyrazine, tetramethyl pyrazine or mixtures thereof.

Examples of the non-sulfur based odorant composition according to the present invention are as follows.

Composition 1, methyl isovalate: methyl acrylate;

Composition 2, methyl isovalate: ethyl acrylate;

Composition 3, ethyl isovalate: methyl acrylate;

Composition 4, ethyl isovalate: ethyl acrylate;

Composition 5, methyl isovalate: methyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 6, methyl isovalate: ethyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 7, ethyl isovalate: methyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 8, ethyl isovalate: ethyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 9, methyl isovalate: methyl acrylate: 2,6-dimethyl pyrazine;

Composition 10, methyl isovalate: ethyl acrylate: 2,6-dimethyl pyrazine;

Composition 11, ethyl isovalate: methyl acrylate: 2,6-dimethyl pyrazine;

Composition 12, ethyl isovalate: ethyl acrylate: 2,6-dimethyl pyrazine;

Composition 13, methyl isovalate: methyl acrylate: 2,3-dimethyl pyrazine;

Composition 14, methyl isovalate: ethyl acrylate: 2,3-dimethyl pyrazine;

Composition 15, ethyl isovalate: methyl acrylate: 2,3-dimethyl pyrazine;

Composition 16, ethyl isovalate: ethyl acrylate: 2,3-dimethyl pyrazine;

Composition 17, methyl isovalate: methyl acrylate: 2-methyl pyrazine;

Composition 18, methyl isovalate: ethyl acrylate: 2-methyl pyrazine;

Composition 19, ethyl isovalate: methyl acrylate: 2-methyl pyrazine;

Composition 20, ethyl isovalate: ethyl acrylate: 2-methyl pyrazine;

Composition 21, methyl isovalate: methyl acrylate: 2-ethyl pyrazine;

Composition 22, methyl isovalate: ethyl acrylate: 2-ethyl pyrazine;

Composition 23, ethyl isovalate: methyl acrylate: 2-ethyl pyrazine;

Composition 24, ethyl isovalate: ethyl acrylate: 2-ethyl pyrazine;

Composition 25, methyl isovalate: propyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 26, ethyl isovalate: propyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 27, propyl isovalate: methyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 28, propyl isovalate: ethyl acrylate: 2-ethyl-3-methyl pyrazine;

Composition 29, methyl isovalate: 2-methyl pyrazine;

Composition 30, ethyl isovalate: 2-ethyl pyrazine.

The non-sulfur based odorant composition according to the present invention has excellent odor performance and odor, such as odor performance and a rapid recovery from olfactory fatigue, exhibits an excellent effect as an odorant even when a small amount is used, and has excellent chemical stability and almost no metal corrosion. Since it does not contain sulfur, when it is contained in the fuel gas, there is an advantage that the exhaust gas such as sulfurous acid gas during combustion is less.

In addition, when used as an odorant for fuel cells, there is no need to remove the sulfur component because it does not contain a sulfur component can solve the existing problems can be useful in fuel cell technology.

The present invention will be described in more detail with reference to the following Examples. However, the following examples are merely examples of the present invention, and the claims of the present invention are not limited thereto.

EXAMPLE

Non-sulfur based odorant according to the present invention was prepared by mixing each odorant in a certain mass ratio as shown in Table 1 below.

In the present invention, the non-sulfur based odorants are firstly selected in the 9-stage odor evaluation method and the 6-stage odor strength method, which are direct functional methods using the human smell, and then, the chemical stability evaluation of the odorants for each metal, the metal corrosion evaluation, and Exhaust gas experiments of sulfur dioxide were conducted and the results are shown in Tables 1 to 3.

Evaluation of quality and odor strength

As shown in Table 1, mixed non-sulfur based odorants were made into various compositions to evaluate the odor and odor intensity by the panel of 13 people. It was evaluated by the 9-stage quality evaluation method and the 6-stage odor intensity method, which are direct sensory methods using the human sense of smell as follows.

The 9-step quality assessment method is evaluated according to the quality of the mixed odorant as follows.

In addition, the six-stage odor strength evaluation method is evaluated according to the odor strength of the mixed odorant as follows.

After injecting about 50% nitrogen gas into 3 L of gas bag in the hood, 3 μL of non-sulfur based odorants as shown in the following Table 1, which are shown in the respective composition, are put in a micro syringe, and the nitrogen gas is added to the gas bag by about 80%. The odorant was completely saturated in the gas bag and stabilized by stabilizing at 25 ° C. for 24 hours, and then, 13 panels were simultaneously subjected to the 9 step quality evaluation method and the 6 step odor intensity method, which are direct functional methods using the human smell. The measured value was used as the average value of three times.

Evaluation of stability according to chemical reactivity

The stability evaluation according to the chemical reactivity for the non-sulfur based odorant is composed of the respective compositions shown in Table 1 below, containing 10 g of the mixed odorant composition in a brown sample container, sealed and left at 25 ° C. for 60 days, and then gas. Measured using chromatography. After 60 days, the stability according to the chemical reactivity can be judged by the number of peaks of the chromatogram of the mixed odorant before standing. The number of peaks of the chromatogram was unchanged because each odorant was chemically stable.

TABLE 1

Metal Corrosion Rating

Metal corrosion evaluation using non-sulfur based odorants was evaluated by using a well polished copper plate, iron plate, nickel plate and aluminum plate, and the non-sulfur odorant composed of the composition shown in Table 2 was added to the odorless additive-free liquefied petroleum gas. Samples were prepared by addition of ppm by weight. After putting the metal in the metal corrosion container, 100 mL of liquefied petroleum gas containing non-sulfur odorant was immersed for 30 days at a temperature of 40 ° C, and the weight of each metal was measured up to 0.0001 g. The weight is compared and the results are shown in Table 2 below. Referring to the results of Table 2 below, all the evaluated metals did not show corrosiveness.

TABLE 2

Emission Reduction Characteristics for Sulfur Dioxide

In order to evaluate the exhaust gas reduction characteristics for sulfurous acid gas, which is the greatest effect of the non-sulfur based odorant of the present invention, the odorant, which is a base sample, is added to the liquefied petroleum gas for summer and the liquefied petroleum gas for winter. A sample prepared by adding 40 ppm by weight of the configured non-sulfur based odorant was used.

The composition of the summer liquefied petroleum gas without the odorant is 1.3 mol% propane, 49.5 mol% iso-butane, 49.2 mol% normal-butane and 5 ppm by weight of sulfur, and the winter liquefied petroleum gas 0.42 mol% ethane, Propane 23.17 mol%, isobutane 27.14 mol%, normal-butane 48.44 mol%, iso-butene 0.26 mol%, iso-pentane 0.57 mol% and sulfur content 5 ppm by weight.

In addition, a comparative sample was prepared by adding 40 ppm by weight of sulfur-based odorant ethyl mercaptan currently in circulation to the liquefied petroleum gas for summer and winter.

The liquefied petroleum gas was measured using a liquefied petroleum gas engine to measure the exhaust gas concentration of sulfur dioxide and compared with the liquefied petroleum gas containing ethyl mercaptan (EM), which is a current sulfur-based odorant. The experimental engine had a displacement of 1,998 cc, a four-stroke four-cylinder DOHC engine, and the fuel injection method was LPI (LPi) LP injection. The concentration of sulfur dioxide gas was analyzed by FT-IR under full load conditions from 1000 rpm to 6000 rpm, and the results are shown in Table 3 below. Referring to the results in Table 3, the liquefied petroleum gas fuel for summer and winter with the addition of the non-sulfur odorant showed an excellent effect by reducing the exhaust gas concentration of sulfur dioxide compared to the liquefied petroleum gas fuel with the sulfur odorant. gave. In addition, sulfur dioxide emissions by load for liquefied petroleum gas for summer and winter with non-sulfur odorant at 2000 rpm were actually reduced compared to sulfur odor, respectively. In the summer liquefied petroleum gas fuel, which is mainly composed of butane, compared to petroleum gas fuel, sulfur dioxide emission reduction effect was greater.

TABLE 3

Claims (5)

At least one selected from (C ₁ to C ₅ ) alkyl isovalate of formula (A); At least one selected from an acrylate compound of Formula 2 (B); And Containing at least one (C) selected from nitrogen-containing compounds of Formula 3; At least one (B) selected from the compound of Formula 2 is a weight ratio (A: B) 3 to 7 with respect to at least one (A) selected from (C ₁ to C ₅ ) alkyl isovalate of Formula 1 : It is used in the range of 7-3 At least one (C) selected from the nitrogen-containing compound of Formula 3 is weight ratio (A: C) 1 with respect to at least one (A) selected from (C ₁ -C ₅ ) alkyl isovalate of Formula 1 : Non-sulfur based odorant composition used in the range of 0.01 to 0.5. [Formula 1]

[Formula 2]

[Formula 3]

[In Formula 1 to Formula 2, R ¹ and R ² are independently selected from linear or branched (C ₁ -C ₅ ) alkyl, and in Formula 3, R ³ to R ⁶ are independently hydrogen, straight chain or Branched (C ₁ -C ₃ ) alkyl.] delete The method of claim 1, Formula 1 to R ¹ and R ² are independently methyl, non-sulfur-component part chwije composition is selected from ethyl or propyl in the formula (2). delete The method of claim 1, At least one selected from the nitrogen-containing compound of formula 3 (C) is 2-ethyl-3-methyl pyrazine, 2,6-dimethyl pyrazine, 2-methyl pyrazine, 2-ethyl pyrazine, 2,3-dimethyl pyrazine, Non-sulfur based odorant composition selected from 2,3-diethyl pyrazine, 2,6-diethyl pyrazine, tetramethyl pyrazine, or mixtures thereof.