Method for green and efficient removal of thiophene sulfides in fuel oil by using Q [8] and application

Abstract

The invention discloses a method for green and efficient removal of thiophene sulfides in fuel oil by using Q [8]. According to the method provided by the invention, a Q [8] solid powder material is adopted to carry out removal treatment on simulated fuel oil containing the thiophene sulfides in a subject-object interaction mode, and the Q [8] solid powder material can be subjected to a regeneration process for reuse through ethanol desorption. The Q [8] solid powder material used in the method is low in cost, the urea is a main raw material for synthesis of the Q [8] solid powder material, and the Q [8] solid powder material is high in selectivity, can be recycled and is more environmentally friendly. The method is simple to operate, convenient to use and low in cost, the combustion simulation oil can be efficiently desulfurized, and environmental pollution is effectively reduced.

Description

Field of the Invention

[0001] The present invention relates to a method and application for green and efficient removal of thiophene sulfides in fuel using Q[8], and particularly relates to the fields of fuel chemistry, polymer chemistry, and environmental protection. Background Art

[0002] Thiophene sulfides (TpSs) are common sulfur-containing pollutants in fuels and chemical products. Their presence leads to a decline in the quality of oil products and the generation of SOx during combustion, exacerbating environmental pollution. Traditional desulfurization methods (such as HDS, ODS) have the following defects:

[0003] They require high-temperature and high-pressure conditions, resulting in high energy consumption;

[0004] The catalysts are expensive and prone to deactivation;

[0005] They have poor selectivity for TpSs.

[0006] In recent years, the adsorption method has become a hot topic in the research direction of deep desulfurization of fuel due to its advantages such as simple process, strong selectivity, mild reaction conditions, and low cost. Commonly used adsorbents include activated carbon, molecular sieves, metal oxides, and metal-organic framework materials (MOFs), etc. However, few of the currently reported adsorption separation materials can be used for industrial actual separation, and there are limitations in terms of stability, selectivity, and regeneration, and the industrialization technology is not yet mature. Therefore, the development of new and efficient adsorbents is the key to realizing deep desulfurization of fuel.

[0007] There is currently no literature report on using Q[8] to remove thiophene sulfides from simulated fuel oil. The present invention uses Q[8] solid powder material to effectively adsorb thiophene sulfides in simulated fuel oil, and the Q[8] solid powder material can be recycled, which is more green and environmentally friendly. This method is simple to operate, convenient to use, and low in cost, and can greenly and efficiently remove thiophene sulfides in simulated fuel oil, effectively reducing environmental pollution. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for green and efficient removal of thiophene sulfides using Q[8]. The Q[8] solid powder material used in this invention has a relatively low cost, and urea is the main raw material for its synthesis. The Q[8] solid powder material removes TpSs from the oil product through a host-guest interaction mode, and the Q[8] solid powder material can be reused through a regeneration process.

[0009] To solve the above technical problems, the present invention is realized by adopting the following technical solutions:

[0010] A method for green and efficient removal of thiophene sulfides in fuel using Q[8]. The method uses Q[8] solid powder material to remove thiophene sulfides in simulated fuel by host-guest interaction, and the Q[8] solid powder material can be regenerated and reused through ethanol desorption.

[0011] The preparation method of the aforementioned Q[8] solid powder material: Mix 480-520 g of urea and 200-220 g of paraformaldehyde, grind evenly, transfer to a three-necked flask, add while stirring to prevent caking and solidification. Then transfer the three-necked flask to a thermostatic oil bath with a temperature set at 90-110 °C. Start timing after the urea and paraformaldehyde are completely dissolved. After 4.5-5.5 h of reflux condensation, take it out to obtain a cucurbituril mixture. Let it stand overnight and then perform suction filtration. The obtained filter cake is mainly a mixture of hexacucurbituril and octacucurbituril. After washing the obtained filter cake with water until the pH value is 7, heat it in a vacuum oven at 95-105 °C for 1.8-2.2 hours to dry. Add the dried solid precipitate to 280-320 mL of 50% formic acid, heat and reflux at 75-85 °C for 7.5-8.5 hours, filter, wash the obtained precipitate with water until the pH value is 7, and recrystallize with 390-410 mL of 6 mol / L hydrochloric acid to obtain octacucurbituril crystals. After washing with water until the pH value is 7, grind it into fine powder to obtain Q[8] solid powder material.

[0012] Specifically, the preparation method of the aforementioned Q[8] solid powder material: Mix 500 g of urea and 210 g of paraformaldehyde, grind evenly, transfer to a three-necked flask, measure 710 mL of 12 mol / L hydrochloric acid and slowly add it to the three-necked flask while stirring to prevent caking and solidification. Then transfer the three-necked flask to a thermostatic oil bath with a temperature set at 100 °C. Start timing after the urea and paraformaldehyde are completely dissolved. After 5 h of reflux condensation, take it out to obtain a cucurbituril mixture. Let it stand for 12 h and then perform suction filtration. The obtained filter cake is mainly a mixture of hexacucurbituril and octacucurbituril. After washing the obtained filter cake with water until the pH value is 7, heat it in a vacuum oven at 100 °C for 2 hours to dry. Add the dried solid precipitate to 300 mL of 50% formic acid, heat and reflux at 80 °C for 8 hours, filter, wash the obtained precipitate with water until the pH value is 7, and recrystallize with 400 mL of 6 mol / L hydrochloric acid to obtain octacucurbituril crystals. After washing with water until the pH value is 7, grind it into fine powder to obtain Q[8] solid powder material.

[0013] The aforementioned thiophene sulfides include thiophene, benzothiophene or dibenzothiophene.

[0014] The aforementioned simulated fuel contains n-octane.

[0015] The aforementioned method for the green and efficient removal of thiophene sulfides in fuel using Q[8] is carried out according to the following steps:

[0016] (1) Take 1 - 3 g of Q[8] solid powder material as the stationary phase and pack it into a glass column with an inner diameter of 5 - 7 mm. Seal both ends with absorbent cotton for later use.

[0017] (2) Add 14 - 16 mL of the simulated oil containing thiophene sulfides to the glass column filled with the Q[8] solid powder material in step (1). The content of thiophene sulfides in the simulated oil is 9 - 15 mmol / L, and collect the effluent.

[0018] Specifically, the aforementioned method is carried out according to the following steps:

[0019] (1) Take 2 g of Q[8] solid powder material as the stationary phase and pack it into a glass column with an inner diameter of 6 mm. Seal both ends with absorbent cotton for later use.

[0020] (2) Add 15 mL of the simulated oil containing thiophene sulfides to the glass column filled with the Q[8] solid powder material in step (1). The content of thiophene sulfides in the simulated oil is 10 mmol / L, and collect the effluent.

[0021] The aforementioned method for the green and efficient removal of thiophene sulfides in fuel using Q[8] is to mix 100 mg of the Q[8] solid powder material with the simulated fuel containing 10 mmol / L of thiophene sulfides, stir at 20 - 30 °C under normal temperature and pressure for 1 - 5 h, with a stirring speed of 240 rpm, and then filter to obtain the product.

[0022] The aforementioned regeneration process is to take out the used Q[8] solid powder material, add it to ethanol and perform ultrasonic oscillation for 0.5 - 1 h for desorption. Subsequently, filter out the Q[8] solid powder material and place it in a vacuum oven at 80 - 120 °C for activation for 6 hours, thus completing the regeneration process of the Q[8] solid powder material.

[0023] The aforementioned application of the Q[8] solid powder material as a desulfurization adsorbent in the desulfurization of simulated fuel.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. High efficiency: The unique internal cavity structure of Q[8] precisely matches with TpSs, and through host - guest interaction, the green and efficient removal of TpSs is achieved. The removal rate of thiophene is 92%, and the removal rates of benzothiophene and dibenzothiophene are 99%.

[0026] 2. Mild operating conditions: The whole process is carried out under normal temperature and pressure, without the need for high - temperature and high - pressure equipment, significantly reducing energy consumption and safety risks.

[0027] 3. Low cost and recyclable: The raw materials of Q[8] are easily available and the synthesis process is simple. The experimental results show that Q[8] has the potential for practical industrial applications, and the removal rates of three kinds of thiophene sulfur all reach more than 95%. In addition, the removal effect does not show an obvious decline within 5 cycles, which not only indicates its good regeneration ability, but also proves that it can meet the requirements of industrial separation and can be used multiple times to bring greater economic benefits;

[0028] 4. Environmental friendliness: There is no catalyst poisoning and no by-products such as hydrogen sulfide are generated. The regenerated solvent can be recycled to avoid secondary pollution;

[0029] 5. Strong industrial compatibility: The process flow is simple and the equipment has strong versatility. It can be directly integrated into the existing desulfurization section of the refinery without complex transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the 1 1H NMR spectrum of Q[8];

[0031] Figure 2 is the PXRD pattern of Q[8];

[0032] Figure 3 is the adsorption equilibrium experimental data graph ((a): thiophene; (b): benzothiophene; (c): dibenzothiophene);

[0033] Figure 4 is the PXRD pattern of the solid powder material of Q[8] after adsorbing TpSs;

[0034] Figure 5 is the removal rate graph of Examples 5 - 7;

[0035] Figure 6 is the regeneration performance and removal rate graph of Examples 9 - 11. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The operation methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0037] Example 1

[0038] Preparation of Q[8] solid powder material: Mix 500 g of urea and 210 g of paraformaldehyde, grind them evenly, transfer them into a three-necked flask, measure 710 mL of 12 mol / L hydrochloric acid and slowly add it to the three-necked flask while stirring to prevent caking and solidification. Then transfer the three-necked flask to a collecting heat type constant temperature oil bath, set the temperature to 100 °C, start timing after the urea and paraformaldehyde are completely dissolved, take it out after refluxing for 5 h to obtain a cucurbituril mixture. Let it stand for 12 h and then perform suction filtration. The obtained filter cake is mainly a mixture of hexacucurbituril and octacucurbituril. After washing the obtained filter cake with water until the pH value is 7, heat and dry it in a vacuum oven at 100 °C for 2 hours. Add the dried solid precipitate to 300 mL of 50% formic acid, heat and reflux at 80 °C for 8 hours, filter, wash the obtained precipitate with water until the pH value is 7, recrystallize with 400 mL of 6 mol / L hydrochloric acid to obtain octacucurbituril crystals, wash with water until the pH value is 7, and grind into fine powder to obtain Q[8] solid powder material.

[0039] The characterization data of the product prepared in this example are as follows:

[0040] 1 The H NMR detection results are as Figure 1 shown. The results show that the spectrum of the obtained Q[8] is consistent with the previously reported Q[8] spectrum. Figure 1 Consistent.

[0041] The PXRD detection results are as Figure 2 shown. The results show that the obtained Q[8] shows sharp peak patterns, indicating that it has a certain crystal structure.

[0042] The following Examples 2 - 8 all use the Q[8] solid powder material prepared in Example 1.

[0043] Example 2

[0044] Dissolve thiophene in n-octane to prepare a simulated oil with a thiophene concentration of 10 mmol / L. Take 15 mL of this simulated oil, add 100 mg of Q[8] solid powder material, stir at a rotation speed of 240 rpm under normal temperature and pressure, and filter. Measure the thiophene content in the liquid phase product.

[0045] The characterization data of the product prepared in this example are as follows:

[0046] The adsorption equilibrium experiment data are as Figure 3 shown. The results show that the equilibrium adsorption capacity of the Q[8] solid powder material for thiophene is 60.25 mg / g.

[0047] The PXRD detection results are as Figure 4As shown, compared with the PXRD pattern of the original Q[8] material, the PXRD pattern of the Q[8] solid powder material after adsorbing thiophene changed, which proved the adsorption of thiophene on Q[8].

[0048] Example 3

[0049] Dissolve benzothiophene in n-octane to prepare a simulated oil with a benzothiophene concentration of 10 mmol / L. Take 15 mL of this simulated oil, add 100 mg of Q[8] solid powder material, stir at a rotation speed of 240 rpm under normal temperature and pressure, and filter. Determine the content of benzothiophene in the liquid-phase product.

[0050] The characterization data of the product prepared in this example are as follows:

[0051] The adsorption equilibrium experimental data are as Figure 3 shown, and the results show that the equilibrium adsorption capacity of the Q[8] solid powder material for benzothiophene is 101.03 mg / g.

[0052] The PXRD test results are as Figure 4 shown. Compared with the PXRD pattern of the original Q[8] material, the PXRD pattern of the Q[8] solid powder material after adsorbing benzothiophene changed, which proved the adsorption of benzothiophene on Q[8].

[0053] Example 4

[0054] Dissolve dibenzothiophene in n-octane to prepare a simulated oil with a dibenzothiophene concentration of 10 mmol / L. Take 15 mL of this simulated oil, add 100 mg of Q[8] solid powder material, stir at a rotation speed of 240 rpm under normal temperature and pressure, and filter. Determine the content of dibenzothiophene in the liquid-phase product.

[0055] The characterization data of the product prepared in this example are as follows:

[0056] The adsorption equilibrium experimental data are as Figure 3 shown, and the results show that the equilibrium adsorption capacity of the Q[8] solid powder material for benzothiophene is 127.93 mg / g.

[0057] The PXRD test results are as Figure 4 shown. Compared with the PXRD pattern of the original Q[8] material, the PXRD pattern of the Q[8] solid powder material after adsorbing dibenzothiophene changed, which proved the adsorption of dibenzothiophene on Q[8].

[0058] Example 5

[0059] 1) Pack 2 g of the Q[8] solid powder material as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for later use;

[0060] 2) Dissolve thiophene in n-octane to prepare a simulated oil with a concentration of 3 mmol / L. Take 15 mL of this simulated oil and add it to a glass column filled with Q[8] solid powder material. Collect the effluent for testing and calculate the removal rate.

[0061] The characterization data of the product prepared in this example are as follows:

[0062] The results show that the Q[8] solid powder material can selectively adsorb thiophene, and the thiophene concentration drops from 2.730 mmol / L to 0.0528 mmol / L;

[0063] Calculate the removal rate of thiophene. The results show that, as Figure 5 shown, the removal rate of thiophene is 98.07%.

[0064] Example 6

[0065] 1) Pack 2 g of Q[8] solid powder material as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for standby;

[0066] 2) Dissolve benzothiophene in n-octane to prepare simulated oils with concentrations of 3 mmol / L respectively. Take 15 mL of this simulated oil and add it to a glass column filled with Q[8] solid powder material. Collect the effluent for testing and calculate the removal rate.

[0067] The characterization data of the product prepared in this example are as follows:

[0068] The results show that the Q[8] solid powder material can selectively adsorb benzothiophene, and the benzothiophene concentration drops from 2.97 mmol / L to 0 mmol / L;

[0069] Calculate the removal rate of benzothiophene. The results show that, as Figure 5 shown, the removal rate of benzothiophene is 100%.

[0070] Example 7

[0071] 1) Pack 2 g of Q[8] solid powder material as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for standby;

[0072] 2) Dissolve dibenzothiophene in n-octane to prepare a simulated oil with a concentration of 3 mmol / L. Take 15 mL of this simulated oil and add it to a glass column filled with Q[8] solid powder material. Collect the effluent for testing and calculate the removal rate..

[0073] The characterization data of the product prepared in this example are as follows:

[0074] The results show that the Q[8] solid powder material can selectively adsorb dibenzothiophene, and the concentration of dibenzothiophene decreases from 3.305 mmol / L to 0 mmol / L.

[0075] Calculate the removal rate of dibenzothiophene. The results show that, as Figure 5 shown, the removal rate of benzothiophene is 100%.

[0076] Example 8

[0077] Regeneration of the Q[8] solid powder material:

[0078] Take out the used Q[8] solid powder material stationary phase, add it to ethanol, and ultrasonically oscillate for more than 0.5 hours for desorption. The ratio of cucurbituril to ethanol is 100 mg:50 mL. Then filter out the Q[8] and put it into a vacuum oven for activation (before using Q[8] for the adsorption experiment, place it in the oven at 80 - 120 °C for vacuum drying for 6 hours), thus completing one regeneration process of Q[8]. The obtained sample is denoted as Q[8]-R.

[0079] The product characterization data prepared in this example are as follows:

[0080] Q[8]-R, 1 H NMR

[0081] In 1 the H NMR spectrum, it is found that the signal of the hydrogen atoms corresponding to TpSs has disappeared, indicating that the Q[8] solid powder material has completed desorption regeneration and all TpSs have been released.

[0082] Example 9

[0083] Reuse of Q[8]:

[0084] 1) Pack 2 g of Q[8]-R as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for standby;

[0085] 2) Dissolve thiophene in n-octane to prepare a simulated oil with a concentration of 3 mmol / L. Take 15 mL of the simulated oil and add it to the glass column filled with Q[8]-R. Collect the effluent for testing and calculate the removal rate.

[0086] Example 10

[0087] Reuse of Q[8]:

[0088] 1) Pack 2 g of Q[8]-R as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for standby;

[0089] 2) Dissolve benzothiophene in n-octane to prepare a simulated oil with a concentration of 3 mmol / L. Take 15 mL of the simulated oil and add it to a glass column filled with Q[8]-R. Collect the effluent for testing and calculate the removal rate.

[0090] Example 11

[0091] Reuse of Q[8]:

[0092] 1) Pack 2 g of Q[8]-R as the stationary phase into a glass column with an inner diameter of 6 mm, and seal both ends with absorbent cotton for standby;

[0093] 2) Dissolve dibenzothiophene in n-octane to prepare a simulated oil with a concentration of 3 mmol / L. Take 15 mL of the simulated oil and add it to a glass column filled with Q[8]-R. Collect the effluent for testing and calculate the removal rate.

[0094] The characterization data of the products prepared in Examples 9-11 are as follows:

[0095] Measure the content of TpSs in the liquid-phase product. The results show that, as Figure 6 shown, the Q[8] solid powder material can selectively adsorb TpSs, and its removal rate is greater than 92%. Moreover, the removal rate does not decrease after being reused 5 times.

[0096] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for green and efficient removal of thiophene sulfides in fuel using Q[8], characterized in that: The method uses Q[8] solid powder material to remove thiophene sulfides in the simulated fuel oil through host-guest interaction, and the Q[8] solid powder material can be regenerated and reused through ethanol desorption.

2. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 1, wherein: The preparation method of the Q[8] solid powder material: Mix 480 - 520 g of urea and 200 - 220 g of paraformaldehyde, grind them evenly, transfer them into a three-necked flask, add and stir simultaneously to prevent caking and solidification. Then transfer the three-necked flask to a thermostatic oil bath with a heat collector, set the temperature to 90 - 110 °C, start timing after the urea and paraformaldehyde are completely dissolved, take it out after 4.5 - 5.5 h of condensation reflux to obtain a cucurbituril mixture. Let it stand for 10 - 14 h and then perform suction filtration. The obtained filter cake is mainly a mixture of hexacucurbituril and octacucurbituril. After washing the filter cake with water until the pH value is 7, heat it in a vacuum oven at 95 - 105 °C for 1.8 - 2.2 h to dry. Add the dried solid precipitate to 280 - 320 mL of 50% formic acid, heat and reflux at 75 - 85 °C for 7.5 - 8.5 h, filter, wash the obtained precipitate with water until the pH value is 7, recrystallize with 390 - 410 mL of 6 mol / L hydrochloric acid to obtain octacucurbituril crystals. After washing with water until the pH value is 7, grind it into fine powder to obtain the Q[8] solid powder material.

3. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 2, characterized in that: The preparation method of the Q[8] solid powder material: Mix 500 g of urea and 210 g of paraformaldehyde, grind them evenly, transfer them into a three-necked flask, measure 710 mL of 12 mol / L hydrochloric acid and slowly add it to the three-necked flask, add and stir simultaneously to prevent caking and solidification. Then transfer the three-necked flask to a thermostatic oil bath with a heat collector, set the temperature to 100 °C, start timing after the urea and paraformaldehyde are completely dissolved, take it out after 5 h of condensation reflux to obtain a cucurbituril mixture. Let it stand for 12 h and then perform suction filtration. The obtained filter cake is mainly a mixture of hexacucurbituril and octacucurbituril. After washing the filter cake with water until the pH value is 7, heat it in a vacuum oven at 100 °C for 2 h to dry. Add the dried solid precipitate to 300 mL of 50% formic acid, heat and reflux at 80 °C for 8 h, filter, wash the obtained precipitate with water until the pH value is 7, recrystallize with 400 mL of 6 mol / L hydrochloric acid to obtain octacucurbituril crystals. After washing with water until the pH value is 7, grind it into fine powder to obtain the Q[8] solid powder material.

4. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 1, characterized in that: The thiophene sulfides include thiophene, benzothiophene or dibenzothiophene.

5. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 1, wherein: The simulated fuel oil is prepared from n-octane.

6. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to any one of claims 1-5, characterized in that: The method is carried out according to the following steps: (1) Take 1 - 3 g of Q[8] solid powder material as the stationary phase and fill it into a glass column with an inner diameter of 5 - 7 mm, and seal both ends with absorbent cotton for standby. (2) Add 14 - 16 mL of simulated fuel oil containing 2 - 5 mmol / L of thiophene sulfides to the glass column filled with Q[8] solid powder material in step (1). The content of thiophene sulfides in the simulated fuel oil is 2 - 5 mmol / L, and collect the effluent.

7. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 6, characterized in that: The method is carried out according to the following steps: (1) Take 2 g of Q[8] solid powder material as the stationary phase and pack it into a glass column with an inner diameter of 6 mm. Seal both ends with absorbent cotton for standby. (2) Add 15 mL of simulated oil containing 3 mmol / L thiophene sulfide to the glass column filled with Q[8] solid powder material in step (1). The content of thiophene sulfide in the simulated oil is 3 mmol / L, and collect the effluent.

8. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to any one of claims 1-5, characterized in that: (2) The specific steps of the method are to mix 100 mg of Q[8] solid powder material with simulated oil containing 10 mmol / L thiophene sulfide, stir at 20 - 30 °C under normal temperature and pressure for 1 - 5 h, with a stirring speed of 240 rpm, and then filter to obtain it.

9. The method for green and efficient removal of thiophene sulfides in fuel using Q[8] according to claim 1, characterized in that: (3) The regeneration process is to take out the used Q[8] solid powder material, add it to ethanol and perform ultrasonic oscillation for 0.5 - 1 h for desorption. The ratio of cucurbituril to ethanol is 100 mg:50 mL. Subsequently, filter out the Q[8] solid powder material and put it into a vacuum oven at 120 °C for activation for 6 hours, thus completing the regeneration process of the Q[8] solid powder material. (4) The application of the Q[8] solid powder material as a desulfurization adsorbent in simulated oil according to claim 1.

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