JPS6280556A - Quantitative and qualitative determination of alcohol in fuel mixed with alcohol - Google Patents

Abstract

PURPOSE:To make easy quantitative determination of alcohol by mixing a drawn sample with an acidic aq. soln. then measuring the decrease of the volume of the separated water layer or the volume of the org. layer and determining the concn. of the alcohol in fuel from the ratio between the volume of the increased or decreased component and the volume of the drawn sample. CONSTITUTION:The quantitative determination of the alcohol in the fuel mixed with alcohol is executed by drawing, for example, 20ml fuel into a separating funnel with 150ml scale, adding 80ml aq. strong acidic soln. (concd. hydrochloric acid:water=1:10) as an extraction liquid thereto and vigorously shaking the mixture for about 5sec. After the separating funnel is rested still, the liquid volume of the water layer is read. The read value is inserted into the equation alcohol concn.% = (volume of the water layer ml-80ml)/20mlX100%, by which the alcohol concn. can be calculated. The precise measurement is made possible by transferring the water layer into a scaled bottle if the alcohol concn. is <=5%.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for quantitatively and qualitatively determining alcohol in an alcohol mixed fuel, particularly in an alcohol/gasoline mixed fuel.

(Prior Art) In recent years, the use of gasoline mixed with alcohol has been put into practical use as an alternative fuel for automobiles. The use of alcohol-containing fuel can cause corrosion in the fuel flow path and deterioration of rubber materials if the military is not made for alcohol fuel, and even if the engine is designed for alcohol fuel, it can cause corrosion depending on the mixing ratio. Therefore, the mixing ratio is an important issue.

In addition, combustion conditions change depending on the alcohol content, causing problems such as not being able to operate under optimal conditions, and fuel absorbing water and causing phase separation.

Therefore, the mixing ratio of alcohol is an important issue when using gasoline mixed with alcohol as a substitute fuel for gasoline. For this reason, each country has set a regulation value for the mixing ratio, but since the mixing of alcohol into gasoline is done independently at filling stations etc., it is not thoroughly enforced, and fuel containing alcohol that far exceeds the regulation value is It may also be sold. Furthermore, since methanol and ethanol have significantly different properties, such as the mixing ratio that causes corrosion, the distinction between them is also an important issue. Therefore, a method of detecting alcohol concentration and distinguishing between methanol and ethanol using a portable device is desired. Currently considered methods for measuring alcohol concentration include infrared absorption spectroscopy, chromatography, and methods by measuring physical parameters such as dielectric constant and capacitance.

(Problems to be Solved by the Invention) However, although the above-mentioned infrared absorption spectroscopy and chromatography are capable of accurate concentration measurement, the devices are large and expensive, making them unsuitable for portability. etc. cannot be used. Furthermore, since the measurement of physical parameters is influenced by external factors such as temperature, it is not easy to obtain accurate measured values. Therefore, it is an object of the present invention to provide a method for quantitatively and qualitatively determining alcohol, which is not influenced by external factors such as temperature, and which uses a small and lightweight instrument so that it can be measured at a gas station or the like.

(Means for Solving the Problems) In order to achieve the above object, the method for quantifying alcohol of the present invention includes mixing a collected sample with an acidic aqueous solution, and then
Measure the increase in the volume of the separated water layer or the decrease in the volume of the aqueous layer, and calculate the alcohol concentration in the fuel from the ratio of the volume of the obtained increase or decrease to the volume of the sample taken. Consisting of In addition, in the qualitative method, after mixing the collected sample with an acidic aqueous solution, the amount of separated water layer (
A portion of both is separated, treated with hydrogen chloride in the presence of ZnCI□, and the presence or absence of methanol is determined based on its reactivity.

Lower alcohols such as methanol and ethanol, which are used in combination with fuels such as gasoline, are highly polar because the hydroxyl group, which is a polar group, occupies a large specific gravity in the molecule (the dipole moment of methanol is 1.70; Ethanol (169) is easily compatible with polar solvents. In contrast, fuels such as gasoline, which are hydrocarbon compounds, are nonpolar (
Since the dipole moment is O), it is insoluble in polar solvents. Thus, methanol or ethanol can be extracted from a methanol- or ethanol-containing fuel with a polar solvent, such as water. On the other hand, alcohol reacts with hydrogen halide to produce alkyl halide and water, but the reactivity of this reaction varies depending on the type of alcohol.
The order of decreasing order is benzyl alcohol, allyl alcohol, tertiary alcohol, secondary alcohol, and primary alcohol. Therefore, for example, t-butyl alcohol reacts with hydrogen halide under relatively mild conditions, but primary alcohols such as methanol and ethanol do not react unless the reaction is accelerated, such as by heating in the presence of a catalyst. For,
Tert-butyl alcohol is reacted with hydrogen halide under conditions such that only tert-butyl alcohol reacts.
The presence of butyl alcohol can be confirmed. Therefore, in the present invention, tert-butyl alcohol is detected by reaction with hydrogen chloride in the presence of ZnCl2 as a catalyst. ZnCl□ is a good Lewis acid and acts as a catalyst in the reaction between alcohol and hydrogen halide as shown in the following formula.

CZn (Old C12) - 10H Ma:==Z n C12+
H,? By the way, methanol is more likely to undergo phase separation due to water absorption than ethanol, and when immersed in fuel, tert-butyl alcohol is usually added as a compatibilizer. Therefore, the presence or absence of methanol can be detected by detecting terL-butyl alcohol.

The method of the present invention is based on the above principle. In the alcohol determination described above, alcohol extraction is preferably carried out by placing the carefully weighed sample and extract into a graduated separatory funnel and shaking. Water is used as the extractant, but other liquids that are easily soluble in alcohols and insoluble in hydrocarbons can also be used. If water is used as it is, it tends to stick to the walls of the extraction vessel, and the boundaries between the aqueous and organic layers are not clear, making it impossible to increase the extraction rate. When used as an acid with sulfuric acid, etc.,
An extraction rate of 100% can be obtained. It is preferable that the amount of the extract is sufficiently large relative to the sample. The alcohol content in the sample can be determined by reading the scale of a graduated separatory funnel as the increase in water stone or decrease in the volume of the organic layer, and if the alcohol concentration is 5%
In the following cases, the aqueous or tastant layer can be transferred to a graduated bottle to obtain accurate readings. The alcohol concentration (%) can be determined by dividing the alcohol content thus determined by the initial volume of the sample.

In the detection of methanol shown above, extraction of alcohol is preferably performed by vigorously stirring the sample and the extract in a separating funnel, but it is not necessary to extract all the alcohol in the sample at this time. Furthermore, since it is necessary to obtain the extract at a high concentration in order to react with hydrogen chloride, it is preferable to use a sufficiently small amount of the extract. The same extract and separating funnel used for concentration measurement can be used. For the reaction with hydrogen chloride, a part of the aqueous layer from which alcohol has been extracted is taken into a reaction tube, and Z n C1 as a catalyst is added.
This is preferably carried out by adding concentrated hydrochloric acid saturated with 2 at room temperature. Further, in the quantitative and qualitative tests described above, some of the instruments and reagents can be used in common, and therefore they can be carried out as a series of methods at a gas station or the like.

(Function) With the above configuration, when measuring the alcohol concentration, the alcohol in the sample is extracted into the aqueous layer with an extraction rate of almost 100%. It can be measured as a decrease, and precise measurement is also possible by using a graduated bottle. When detecting methanol, when the alcohol in the sample is extracted at a high concentration and concentrated hydrochloric acid and ZnC1z are added to this, if tert-butyl alcohol is present in the sample, alkyl halides are generated and the sample becomes cloudy. The presence of tert-butyl alcohol is confirmed, and therefore the presence of methanol can be confirmed f1.

(Examples) Hereinafter, the present invention will be described in further detail based on Examples.

Example 1: Quantitative determination of alcohol 20 ml of fuel is collected into a 150 ml graduated separatory funnel. Strongly acidic aqueous solution (concentrated hydrochloric acid: water = 1:
10) Add 80ml and shake vigorously for 5 seconds. After leaving the separating funnel still, read the liquid volume of the aqueous layer and insert this value into the formula below to calculate the alcohol concentration (%).

Amount of water layer (m 1 ) -80 ml Alcohol concentration % = X
1000ml If the alcohol concentration is less than 5%, transfer the aqueous layer to a graduated bottle and measure accurately.

Example 2: Alcohol Qualitative Test Approximately 100 ml of fuel is collected into a 150 ml graduated separatory funnel. If the alcohol concentration measured above is 4% or more, add 2 ml of Reagent 1 (concentrated hydrochloric acid: water = 1:1), and if it is less than 4%, add 2 ml of Reagent 2 (concentrated hydrochloric acid) and stir vigorously for 5 seconds. Thereafter, the separatory funnel was left still, 1 ml of water was put into the reaction tube, 2 ml of reagent 3 (a solution of Z n C11 saturated in 100 cC of concentrated hydrochloric acid) was added, and the mixture was stirred gently. If the reaction solution becomes cloudy, the presence of methanol is confirmed.

The methods of Examples 1 and 2 above can be carried out with the following equipment and reagents: 150 ml separatory funnel, 5 Q m 1 and 20 ml O pipets, three 2 ml pipets, reaction tubes. 5 bottles, graduated bottles, 2 waste layers, 2 funnel stands, extraction aqueous solution, reagents 1, 2 and 3° These instruments and reagents are 35 x 50 x 20 cm in height x width x depth.
It can be stored in a box that is m.

Example 3: Gasoline containing methanol at concentrations of 2%, 10% and 50% and tert-butyl alcohol as an additive was used as a known sample, and the volume ratio of hydrochloric acid to water (HC1/ H2O”) is 115.1
A quantitative test was conducted according to the method of Example 1 using four types of aqueous hydrochloric acid solutions of /10.1150 and 1/100. The extraction rate was determined from the resulting value and the actual content. The results are shown in the graph of FIG. As is clear from the graph, an extraction rate of approximately 100% was obtained with an extract having a ratio of HC1/H2O of 1/10 or more. Ethanol has an extraction rate of almost 100% at pH 2 or below, and methanol has a
An aqueous hydrochloric acid solution with a Cl/H2O ratio of 1/10 or more yields an extraction rate of almost 100% at each concentration, so HC
It is clear that both methanol and ethanol are extracted with an extraction rate of approximately 100% by an aqueous hydrochloric acid solution with a ratio of 1/10 l/HzO.

Example 4: Containing methanol as a known sample at concentrations of 5%, 4%, 3%, 2% and 1% and te as an additive.
Using gasoline containing rt-butyl alcohol,
H2O/HCI as extract liquid 0/1.1/1.2/1
The qualitative test of Example 2 was conducted using a 3/1 hydrochloric acid aqueous solution. The results are shown in the table below.

In the table, the ○ mark indicates that cloudiness can be easily confirmed, and the Δ mark indicates that it is cloudy! The mark "X" indicates that it is difficult to confirm the white turbidity. For each methanol concentration, an aqueous hydrochloric acid solution with a concentration indicated by ○ or Δ can be used, but for methanol concentrations of 4% or less, concentrated hydrochloric acid is used, and for methanol concentrations of less than 4%, HO/HCI is 1/1.
can be detected reliably by using an aqueous solution of hydrochloric acid.

(Effects of the Invention) The method for quantitatively determining and qualitatively determining alcohol in alcohol mixed fuel according to the present invention is applicable to methanol, ethanol, and t
It was created by utilizing the physical and chemical properties of ert-butyl alcohol, and it is quantitatively determined by extracting methanol or ethanol mixed in gasoline with an acidic aqueous solution, and qualitatively by reacting it with hydrogen halide. do. Therefore, measurements can be made using small, lightweight, and inexpensive instruments and reagents such as a separating funnel, reaction tube, etc., and these instruments can be stored in a portable box.

Furthermore, the operation is simple, and since it is not affected by external factors such as temperature and humidity, skilled techniques are not required to obtain accurate measurement values. Therefore, by the method of the present invention, quantitative and qualitative determination of alcohol can be easily carried out at a gas station or the like.

[Brief explanation of drawings]

FIG. 1 is a graph showing the extraction rate of methanol in the quantitative test of Example 3. Patent applicant Suzuki Motor Co., Ltd. Agent (
Patent Attorney) Yumi Yu 1 drawing HHCVH20 (V/y) MeOH: Methanol TBA: tert-) °Chill alcohol procedural amendment November 8, 1985 Commissioner of the Patent Office Ribe 1. Display of 19 items Showa 1960 Patent Application No. 220840 2, Name of the invention, Method for quantifying and qualitatively determining alcohol in alcohol mixed fuel 3, Relationship with the amended person's case Name of patent applicant (208) Suzuki Motor Co., Ltd. 4, Agent
Address: 1-6 Kanda Surugadai, Chiyoda-ku, Tokyo (and 1 other person) 5. Date of amendment order “Voluntary” 6. Subject of amendment 7. Lines 4 to 2 from the bottom of page 13 of the statement of contents of the amendment: “Methanol concentration··
・IO/1 (CI
/ Correct with HCI J. that's all

Claims (2)

[Claims] (1) After mixing the collected sample with an acidic aqueous solution, measure the increase in the volume of the separated aqueous layer or the decrease in the volume of the organic layer, and measure the volume of the obtained increase or decrease and the volume of the sample collected. A method for quantifying alcohol in alcohol-mixed fuel, which consists of determining the concentration of alcohol in the fuel from the ratio of (2) After mixing the collected sample with an acidic aqueous solution, at least a portion of the separated aqueous layer is fractionated, and hydrogen chloride is applied in the presence of ZnCl_2 to identify the presence or absence of methanol based on its reactivity. A method for qualitatively determining alcohol in alcohol-mixed fuel, characterized by: