Method for preserving carbonyl-free ethanol solutions and use thereof

Abstract

The application discloses a kind of preservation methods and application of carbonyl-free ethanol solution, it is related to petroleum chemical product analysis determination technical field.The application comprises adding reducing agent to carbonyl-free ethanol and filling reducing gas, and is stored at 10-35 DEG C.Through adding reducing agent to carbonyl-free ethanol, and filling reducing gas to ensure the purity of carbonyl-free ethanol, so that carbonyl-free ethanol can also be stably stored under normal temperature condition, prolongs the preservation period and use period of carbonyl-free ethanol, long-term keeps solution low test baseline, ensures that carbonyl-free ethanol solution has preferable detection precision, greatly shortens detection period.Simultaneously, the method is simple in operation, and the preservation condition is convenient, and the preservation cost is low, is conducive to long-term storage of carbonyl-free ethanol solution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of petroleum and chemical product analysis and determination, in particular to a preservation method of a non-carbonyl ethanol solution and application thereof. BACKGROUND

[0002] With the rapid development of chemical industry, the output of Fischer-Tropsch synthetic oil is rapidly increasing. It is of great significance to accurately and rapidly determine the content of carbonyl compounds in Fischer-Tropsch distillate oil. At present, non-carbonyl ethanol is mainly used as a control to detect the content of carbonyl compounds in Fischer-Tropsch distillate oil. However, with the increase of storage time, the test baseline of non-carbonyl ethanol is constantly rising, thereby leading to the reduction of analysis sensitivity and accuracy. At present, the storage standard of GB / T601-2016 used for the storage of standard titration solution of chemical reagent only stipulates the storage standards of iodine standard titration solution, sodium nitrite standard titration solution, perchloric acid standard titration solution, potassium hydroxide-ethanol standard titration solution and ferric ammonium sulfate standard titration solution, and does not give the preservation method of non-carbonyl ethanol.

[0003] In the prior art, in order to obtain better detection sensitivity, non-carbonyl ethanol often needs to be prepared and used immediately, which seriously affects the detection efficiency. Therefore, how to effectively preserve non-carbonyl ethanol solution is a problem to be solved in the field.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide a preservation method of non-carbonyl ethanol solution and application of the preservation method of non-carbonyl ethanol solution in the field of petroleum and chemical product analysis and determination.

[0006] The present application is realized in the following manner:

[0007] In a first aspect, the present application provides a preservation method of non-carbonyl ethanol solution, which comprises adding a reducing agent to non-carbonyl ethanol and filling a reducing gas, and storing at 10-35℃.

[0008] In an optional embodiment, the reducing agent comprises any one of hexene, pyridine and hexyne.

[0009] In an optional embodiment, the volume of hexene is 1-10% of the volume of non-carbonyl ethanol, preferably 4-10%, and more preferably 8-10%.

[0010] In an optional embodiment, the volume of pyridine is 1-20% of the volume of non-carbonyl ethanol, preferably 5-8%.

[0011] In an optional embodiment, the reducing gas comprises any one of hydrogen, carbon monoxide, methane and sulfur monoxide.

[0012] In an optional embodiment, the amount of the reducing gas added is 1-10 min, preferably 1-5 min, and more preferably 3-5 min.

[0013] In an optional embodiment, the storage time is 6-12 months.

[0014] In an optional embodiment, the method for preparing the non-carbonyl ethanol comprises adding 2,4-dinitrophenylhydrazine and concentrated hydrochloric acid to the non-aldehyde ethanol, and heating to reflux.

[0015] In an optional embodiment, 0.8-1.2 g of 2,4-dinitrophenylhydrazine and 1-2 ml of concentrated hydrochloric acid are added to every 180-220 ml of non-aldehyde ethanol.

[0016] Preferably, the heating to reflux time is 1-3 h, and the heating to reflux temperature is 80-90℃.

[0017] In a second aspect, the present application provides a use of the storage method of the non-carbonyl ethanol solution according to any one of the preceding embodiments in the field of analysis and determination of petrochemical products.

[0018] The present application has the following beneficial effects:

[0019] The present application provides a storage method and use of a non-carbonyl ethanol solution. By adding a reducing agent to the non-carbonyl ethanol and filling reducing gas to ensure the purity of the non-carbonyl ethanol, the non-carbonyl ethanol can be stably stored at room temperature, the storage and use periods of the non-carbonyl ethanol are extended, the solution maintains a low test baseline for a long time, the non-carbonyl ethanol solution has good detection accuracy, and the detection period is greatly shortened. At the same time, the method is simple to operate, the storage conditions are convenient, and the storage cost is low, which is conducive to long-term storage of the non-carbonyl ethanol solution. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0021] In a first aspect, the present application provides a storage method of a non-carbonyl ethanol solution, which comprises adding a reducing agent to the non-carbonyl ethanol and filling reducing gas, and storing at 10-35℃.

[0022] The carbonyl-free ethanol solution is an important reference for determining the content of carbonyl compounds in the Fischer-Tropsch distillate. The carbonyl content in the Fischer-Tropsch distillate needs to be determined based on the test baseline of the carbonyl-free ethanol, however, the test baseline of the carbonyl-free ethanol will increase with the increase of the storage time, thereby leading to the decrease of the analysis sensitivity and accuracy. At present, there is no relevant storage standard for the carbonyl-free ethanol. Therefore, in order to obtain better detection sensitivity, it is often necessary to prepare and use it immediately, which seriously affects the detection efficiency and the refining cost of the carbonyl-free ethanol. Therefore, the inventors propose to add a reducing agent to the carbonyl-free ethanol and fill the reducing gas to ensure the purity of the carbonyl-free ethanol, so that the carbonyl-free ethanol can be stably stored at room temperature, thereby prolonging the storage period and use period of the carbonyl-free ethanol, keeping the solution low test baseline for a long time, ensuring that the carbonyl-free ethanol solution has better detection accuracy, and greatly shortening the detection period. At the same time, the method is simple to operate, the storage condition is convenient, and the storage cost is low, which is beneficial to the long-term storage of the carbonyl-free ethanol solution.

[0023] In an optional embodiment, the storage temperature of the carbonyl-free ethanol solution is 15-25℃.

[0024] In an optional embodiment, the reducing agent includes but is not limited to any one of hexene, pyridine, and hexyne, as long as the reducing property is stronger than that of the carbonyl-free ethanol and does not affect the use of the carbonyl-free ethanol.

[0025] In an optional embodiment, the volume of the hexene is 1-10% of the volume of the carbonyl-free ethanol, preferably 4-10%, and more preferably 8-10%.

[0026] In an optional embodiment, the volume of the pyridine is 1-20% of the volume of the carbonyl-free ethanol, preferably 5-8%.

[0027] In an optional embodiment, the reducing gas includes any one of hydrogen, carbon monoxide, methane, and sulfur monoxide.

[0028] In an optional embodiment, the reducing gas is added for 1-10 min, preferably 1-5 min, and more preferably 3-5 min under normal pressure.

[0029] In an optional embodiment, the storage time is 6-12 months.

[0030] In an optional embodiment, the preparation method of the carbonyl-free ethanol includes adding 2,4-dinitrophenylhydrazine and concentrated hydrochloric acid to the non-formaldehyde ethanol, and heating and refluxing.

[0031] In an optional embodiment, 0.8-1.2 g of 2,4-dinitrophenylhydrazine and 1-2 ml of concentrated hydrochloric acid are added to every 180-220 ml of non-formaldehyde ethanol.

[0032] Preferably, the heating reflux time is 1-3 hours, and the heating reflux temperature is 80-90℃.

[0033] Preferably, the low-temperature cooling circulation pump is opened during the heating reflux, and the nitrogen gas is set to be ≤1.5 MPa.

[0034] Preferably, a thorn-shaped reflux device is selected during the heating reflux.

[0035] Preferably, after the heating reflux is completed, the solution is allowed to stand for 30 minutes, the heating reflux is continued, the low-temperature cooling circulation pump is opened, the thorn-shaped reflux device is replaced by a ball-shaped reflux device, the nitrogen gas pressure is adjusted to be ≥3 MPa, the first and last portions of the solution are discarded, and only the middle portion of the solution is reserved, which is the carbonyl-free ethanol solution.

[0036] In a second aspect, the present application provides an application of a preservation method of the carbonyl-free ethanol solution according to any one of the preceding embodiments in the field of analysis and determination of petrochemical products.

[0037] The features and performances of the present application are further described in detail below in combination with embodiments.

[0038] Embodiment 1

[0039] The present embodiment provides a preservation method of a carbonyl-free ethanol solution, which comprises the following steps:

[0040] S01, preparation of a carbonyl-free ethanol solution

[0041] In a three-mouth flask, 2000 mL of formaldehyde-free ethanol, 10.0 g of 2,4-dinitrophenylhydrazine, and 20-25 drops of concentrated hydrochloric acid (about 15 mL) are added. A temperature control 518P digital temperature controller is opened, and the reaction temperature is controlled at 86℃. Then, the three-mouth flask is placed in a heating pot to start heating. A low-temperature cooling circulation pump is opened, and the nitrogen gas is set to be ≤1.5 MPa. A thorn-shaped reflux device is installed on the three-mouth flask for refluxing for 2 hours. After the reaction is completed, the solution is allowed to stand for 30 minutes. The temperature control 518P digital temperature controller and the low-temperature cooling circulation pump are opened. The thorn-shaped reflux device is replaced by a ball-shaped reflux device. The nitrogen gas pressure is adjusted to be ≥3 MPa. The first 30 mL and the bottom 50 mL of the solution are discarded. The middle portion of the solution is collected to obtain a clear and transparent colorless liquid. The absorbance of the liquid is detected to be 0.008, and the carbonyl value is 0. This is the carbonyl-free ethanol solution.

[0042] S02, preservation of the carbonyl-free ethanol solution

[0043] The carbonyl-free ethanol solution prepared in the step S01 is placed in a stainless steel cylinder. A reducing agent is added. A reducing gas is filled at normal pressure. Then, the solution is sealed and preserved at room temperature.

[0044] Test Example 1

[0045] The carbonyl-free ethanol solution in S01 of Example 1 was used as a reference solution to compare the quality of the carbonyl-free ethanol solution stored under different conditions.

[0046] 1. The reducing agent in S02 was hexene and the reducing gas was hydrogen. The solution was stored at room temperature, about 25°C, for 6 months. The effects of the hexene content and the hydrogen charging time on the quality of the carbonyl-free ethanol solution are shown in Table 1.

[0047] Table 1 Quality changes of the carbonyl-free ethanol solution stored at room temperature with hexene-hydrogen

[0048] No. Hexene content (% v / v) Hydrogen charging time (min) Absorbance 1-1 1 1 0.065 1-2 1 3 0.056 1-3 1 5 0.045 1-4 4 1 0.034 1-5 4 3 0.022 1-6 4 5 0.018 1-7 8 1 0.013 1-8 8 3 0.008 1-9 8 5 0.009 1-10 10 1 0.012 1-11 10 3 0.008 1-12 10 5 0.009 Detection reference liquid - - 0.008

[0049] As shown in Table 1, both the low hexene content and the short hydrogen charging time can affect the quality of the carbonyl-free ethanol solution.

[0050] 2. The reducing agent in S02 was pyridine and the reducing gas was hydrogen. The solution was stored at room temperature, about 25°C, for 6 months. The effects of the pyridine content and the hydrogen charging time on the quality of the carbonyl-free ethanol solution are shown in Table 2.

[0051] Table 2 Quality changes of the carbonyl-free ethanol solution stored at room temperature with pyridine-hydrogen

[0052] No. Pyridine content (% v / v) Hydrogen charging time (min) Absorbance 2-1 1 1 0.044 2-2 1 3 0.037 2-3 1 5 0.025 2-4 5 1 0.012 2-5 5 3 0.007 2-6 5 5 0.009 2-7 8 1 0.011 2-8 8 3 0.008 2-9 8 5 0.010 Detection reference liquid - - 0.008

[0053] As shown in Table 2, both the low pyridine content and the short hydrogen charging time can affect the quality of the carbonyl-free ethanol solution.

[0054] 3. The reducing agent in S02 was 8% (v / v) hexene and 5% (v / v) pyridine, respectively. The solution was stored at room temperature, about 25°C, for 6 months. The effects of the hydrogen charging on the quality of the carbonyl-free ethanol solution are shown in Table 3.

[0055] Table 3 Effects of hydrogen charging on the quality of the carbonyl-free ethanol solution

[0056]

[0057]

[0058] As shown in Table 3, without hydrogen charging, the quality of the carbonyl-free ethanol solution can be significantly reduced under the same storage conditions. Therefore, the use of the reducing gas can prolong the storage time of the carbonyl-free ethanol solution.

[0059] 4. The reducing gas in S02 was hydrogen and the hydrogen charging time was 3 min. The solution was stored at room temperature, about 25°C, for 6 months. The effects of the reducing agent on the quality of the carbonyl-free ethanol solution are shown in Table 4.

[0060] Table 4 Effect of addition of reducing agent on quality of carbonyl-free ethanol solution

[0061]

[0062] As shown in Table 4, without adding reducing agent, the quality of the carbonyl-free ethanol solution is significantly reduced under the same other storage conditions. Therefore, the use of reducing agent can prolong the storage time of the carbonyl-free ethanol solution.

[0063] 5, The carbonyl-free ethanol solution prepared in S01 step of Example 1 was stored by different storage methods, and the storage conditions and storage results are shown in Table 5.

[0064] Table 5 Effect of different storage methods on quality of carbonyl-free ethanol solution

[0065]

[0066]

[0067] As shown in Table 5, the absorbance of the carbonyl-free ethanol solution after adding reducing agent and reducing gas in the present application under normal temperature conditions has almost no change compared with the detection reference liquid, while the absorbance of the solution after directly storing the carbonyl-free ethanol solution prepared in S01 step of Example 1 under low temperature (0℃) and ultra-low temperature (-15℃) conditions is significantly increased, which indicates that the storage method of the carbonyl-free ethanol solution provided by the present application not only has simple storage conditions, but also can better maintain the quality of the carbonyl-free ethanol solution.

[0068] 6, The carbonyl-free ethanol solution prepared in S01 step of Example 1 was stored by different storage methods at room temperature, about 25℃, for 6 months, and the storage conditions and storage results are shown in Table 6.

[0069] Table 6 Effect of different storage methods on quality of carbonyl-free ethanol solution

[0070] No. Storage method Vacuum or not Absorbance 6-1 Hexene 8% (v / v), hydrogen charging 3 min No 0.008 6-2 Pyridine 5% (v / v), hydrogen charging 3 min No 0.007 6-3 Direct storage Yes 0.066 Detection reference liquid - - 0.008

[0071] As shown in Table 6, the absorbance of the carbonyl-free ethanol solution after adding reducing agent and reducing gas in the present application under normal temperature conditions has almost no change compared with the detection reference liquid, while the absorbance of the solution after directly storing the carbonyl-free ethanol solution prepared in S01 step of Example 1 under low temperature (0℃) and ultra-low temperature (-15℃) conditions is significantly increased, which indicates that the storage method of the carbonyl-free ethanol solution provided by the present application not only has simple storage conditions, but also can better maintain the quality of the carbonyl-free ethanol solution.

[0072] 7, The carbonyl-free ethanol solution prepared in S01 step of Example 1 was stored by different storage methods, and the storage conditions and storage results are shown in Table 7.

[0073] Table 7 Effects of different preservation methods on the quality of the non-ketonic ethanol solution As shown in Table 7, the absorbance of the non-ketonic ethanol solution prepared by adding the reducing agent and the reducing gas to the non-ketonic ethanol solution and then stored at room temperature has almost no change compared with the detection reference liquid, while the absorbance of the non-ketonic ethanol solution prepared by directly vacuumizing the non-ketonic ethanol solution prepared in step S01 of Example 1 and then storing at ultra-low temperature (-15℃) is still significantly increased, which indicates that the preservation method of the non-ketonic ethanol solution provided by the present application not only has simple storage conditions, but also can preferably maintain the quality of the non-ketonic ethanol solution.

[0074] 8. The absorbance of the non-ketonic ethanol solution prepared by using the preservation method of Example 1 to seal and store the non-ketonic ethanol solution at room temperature (about 25℃) for different storage time is shown in Table 8.

[0075] Table 8 Effects of different preservation methods on the quality of the non-ketonic ethanol solution

[0076] No. Storage method Storage time (month) Absorbance 8-1 Hexene 8% (v / v), hydrogen charging 3 min 6 0.008 8-2 Hexene 8% (v / v), hydrogen charging 3 min 12 0.010 8-3 Pyridine 5% (v / v), hydrogen charging 3 min 6 0.007 8-4 Pyridine 5% (v / v), hydrogen charging 3 min 12 0.009 Detection reference liquid - - 0.008

[0077] As shown in Table 8, the absorbance of the non-ketonic ethanol solution prepared by using the preservation method provided by the present application has almost no change compared with the detection reference liquid after 12 months of storage, which indicates that the preservation method of the non-ketonic ethanol solution provided by the present application can significantly prolong the storage time of the non-ketonic ethanol solution, has simple storage conditions, and has high preservation quality of the non-ketonic ethanol solution.

[0078] The preferred embodiments of the present application have been described above with reference to the drawings, but the present application is not limited to the above examples, and various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preserving a carbonyl-free ethanol solution, characterized in that, This includes adding a reducing agent to carbonyl-free ethanol and purging it with a reducing gas, then storing it at 10~35℃; The reducing agent includes any one of hexene, pyridine, and hexyne; The volume of the hexene is 8-10% of the volume of carbonyl ethanol; The volume of the pyridine is 5-8% of the volume of carbonyl ethanol; The reducing gas includes any one of hydrogen, carbon monoxide, methane, and sulfur monoxide; The amount of reducing gas added is 1-10 minutes of atmospheric pressure inflation; The storage period is 6 to 12 months.

2. The preservation method according to claim 1, characterized in that, The amount of reducing gas added is 1-5 minutes of atmospheric pressure inflation.

3. The preservation method according to claim 1, characterized in that, The amount of reducing gas added is 3-5 minutes of atmospheric pressure inflation.

4. The preservation method according to claim 1, characterized in that, The preparation method of carbonyl-free ethanol includes adding 2,4-dinitrophenylhydrazine and concentrated hydrochloric acid to aldehyde-free ethanol and heating under reflux.

5. The preservation method according to claim 4, characterized in that, Add 0.8-1.2g of 2,4-dinitrophenylhydrazine and 1-2ml of concentrated hydrochloric acid to every 180-220ml of formaldehyde-free ethanol.

6. The preservation method according to claim 4 or 5, characterized in that, The heating and reflux time is 1-3 hours, and the heating and reflux temperature is 80-90℃.

7. The application of a method for preserving a carbonyl-free ethanol solution as described in any one of claims 1 to 6 in the field of petrochemical product analysis and determination.

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