A method and system for ultrasonic oxidation desulfurization of gasoline and diesel

Abstract

The present application relates to a method and system for ultrasonic oxidation desulfurization of gasoline and diesel, and the desulfurization method includes: S1, mixing an oxidant solution and an organic acid catalyst solution to form a mixed solution, wherein the oxidant reacts with the organic acid catalyst to form a peroxy acid, S2, mixing the mixed solution with gasoline and diesel and heating it to 50-70°C, and performing an ultrasonic oxidation reaction under an ultrasonic wave of 15-25KHz to obtain preformed oil; wherein the mass flow ratio of the oxidant solution, the organic acid catalyst solution and the gasoline and diesel is (0.03-0.08): (0.01-0.03): 1; S3, performing phase separation treatment on the preformed oil, wherein the upper layer is gasoline and diesel containing sulfone and sulfoxide, and the lower layer is an aqueous phase containing an organic acid catalyst; S4, recovering the organic acid catalyst, and countercurrent extraction of gasoline and diesel to obtain desulfurized gasoline and diesel. The present application can improve the oxidative desulfurization effect of gasoline and diesel while reducing the waste of oxidants and the difficulty of recovering organic acid catalysts.

Description

Technical Field

[0001] The present application relates to the field of gasoline and diesel desulfurization technology, and in particular to a gasoline and diesel ultrasonic oxidation desulfurization method and a desulfurization system. Background Art

[0002] Diesel and gasoline usually contain a certain amount of sulfur compounds, which can easily cause corrosion of metal equipment in fuel machinery; and after diesel and gasoline are burned, they generate SOx, which leads to acid rain and environmental pollution. The sulfur compounds in diesel and gasoline are mainly thiophene sulfur. At present, the methods for desulfurizing diesel and gasoline mainly include oxidative desulfurization, biological desulfurization and extractive desulfurization. Among them, oxidative desulfurization technology is widely used because it does not use hydrogen source, has low investment and operating costs, and has mild reaction conditions.

[0003] The process of oxidative desulfurization is as follows: first, the oxidant and organic acid are mixed to generate peroxy acid, and then the peroxy acid reacts with diesel or gasoline to obtain preformed oil containing sulfoxides or sulfones. The preformed oil is passed into an extraction tower to extract and separate the sulfoxides or sulfones in the preformed oil to achieve the purpose of desulfurization of diesel and gasoline. In addition, in order to improve the effect of oxidative desulfurization, the oxidative desulfurization process is usually placed in an ultrasonic reactor to increase the oxidation rate and the effect of oxidative desulfurization.

[0004] In the process of industrial desulfurization of diesel and gasoline, diesel or gasoline needs to be continuously introduced into an ultrasonic reactor at a certain flow rate for oxidative desulfurization. If the ratio between the flow rate of the corresponding oxidant and organic acid catalyst introduced into the ultrasonic reactor and the flow rate of diesel or gasoline is small, the oxidative desulfurization effect of diesel and gasoline will be poor; if the ratio between the flow rate of the corresponding oxidant and organic acid catalyst introduced into the ultrasonic reactor and the flow rate of diesel or gasoline is large, it will make it difficult for the peroxy acid generated by the reaction of the oxidant and the organic acid catalyst to react with the sulfur-containing compounds in diesel or gasoline to generate thiophene sulfur, resulting in excess peroxy acid, and causing waste of oxidant, and it will also increase the difficulty of recovering the organic acid catalyst. Summary of the invention

[0005] In order to improve the oxidative desulfurization effect while reducing the waste of oxidants and the difficulty of recovering organic acid catalysts, the present application provides a gasoline and diesel ultrasonic oxidative desulfurization method and a desulfurization system.

[0006] The present application provides a gasoline and diesel ultrasonic oxidation desulfurization method and desulfurization system using the following technical solutions:

[0007] A method for ultrasonic oxidation desulfurization of gasoline and diesel, comprising:

[0008] S1, mixing an oxidant solution and an organic acid catalyst solution to form a mixed solution, wherein the oxidant reacts with the organic acid catalyst to form a peroxy acid;

[0009] S2, mixing the mixed liquid with gasoline and diesel and heating to 50-70° C., and performing ultrasonic oxidation reaction under 15-25KHz ultrasonic wave to obtain preformed oil; wherein the mass flow ratio of the oxidant solution, the organic acid catalyst solution and the gasoline and diesel is (0.03-0.08): (0.01-0.03): 1;

[0010] S3, performing phase separation treatment on the preformed oil, wherein the upper layer is gasoline and diesel containing sulfone and sulfoxide, and the lower layer is an aqueous phase containing the organic acid catalyst;

[0011] S4, recovering the organic acid catalyst, and performing countercurrent extraction on the gasoline and diesel to obtain desulfurized gasoline and diesel.

[0012] By adopting the above technical scheme, in the process of industrial desulfurization of gasoline and diesel, an oxidant solution with a flow rate of 3-8% of the flow rate of gasoline or diesel and an organic acid catalyst solution with a flow rate of 1-3% of the flow rate of gasoline or diesel are respectively introduced, so that the introduced oxidant and organic acid catalyst can continuously mix and react to generate a relatively appropriate amount of peroxy acid, so that an appropriate amount of peroxy acid can continuously react with the introduced gasoline or diesel for oxidation. The relatively appropriate amount of peroxy acid flow can fully oxidize the thiophene sulfur contained in gasoline or diesel into sulfoxides or sulfones as much as possible, so that the sulfur content in gasoline or diesel is lower than that of the existing desulfurization technology, so as to improve the oxidative desulfurization effect of gasoline or diesel; at the same time, the relatively appropriate amount of peroxy acid can react with the thiophene sulfur in gasoline or diesel as completely as possible, so that the peroxy acid can be reduced as completely as possible to generate an organic acid catalyst, so that the amount of peroxy acid after ultrasonic oxidation is as small as possible. The remaining amount of peroxyacid after ultrasonic oxidation is as small as possible, so that while improving the oxidative desulfurization effect, the waste of oxidant and the difficulty of recovering the organic acid catalyst can be reduced.

[0013] Optionally, the method for recovering the organic acid catalyst comprises:

[0014] The aqueous phase containing the organic acid catalyst is dried and dehydrated by a desiccant, and the dehydrated organic acid catalyst is formulated into a solution and then introduced into the mixed solution in step S1.

[0015] By adopting the above technical solution, the aqueous phase of the organic acid catalyst is dried and dehydrated by a desiccant to generate a dehydrated organic acid catalyst. The dehydrated organic acid catalyst is re-proportioned into an organic acid catalyst solution and re-introduced into the mixed solution for generating peroxy acid by reaction. The organic acid catalyst can react with the oxidant again to generate peroxy acid, so as to realize the recycling of the organic acid catalyst, save costs and improve environmental protection.

[0016] Optionally, the desiccant is passed through saturated steam at 170-190° C. and 0.5-2 MPa, the desiccant is heated to 150-170° C. to perform the drying and dehydration treatment step, and the dehydrated desiccant is reintroduced into the aqueous phase containing the organic acid catalyst.

[0017] By adopting the above technical solution, after the desiccant dries and dehydrates the aqueous phase of the organic acid catalyst, the desiccant will be saturated with water. The desiccant is dried and dehydrated to make it unsaturated with water, and the dehydrated desiccant is reintroduced into the aqueous phase containing the organic acid catalyst. The desiccant can dehydrate the organic acid catalyst again to achieve the recycling of the desiccant, further saving costs and improving environmental protection.

[0018] Optionally, the method further comprises the following step of post-treating the desulfurized gasoline and diesel:

[0019] The desulfurized gasoline and diesel are subjected to solvent removal at 90-110° C. and 0.5-1.5 kPaA to obtain desolventized desulfurized gasoline and diesel.

[0020] By adopting the above technical scheme, gasoline or diesel containing sulfone and sulfoxide is subjected to countercurrent extraction to obtain desulfurized gasoline and diesel containing a small amount of solvent. The desulfurized gasoline and diesel are subjected to reduced pressure distillation at 90-110°C and 0.5-1.5kpaA to remove a small amount of solvent in the desulfurized gasoline and diesel to obtain desolventized desulfurized gasoline and diesel, thereby improving the quality of the product oil.

[0021] Optionally, while countercurrent extraction is performed on the desulfurized gasoline and diesel to obtain the desulfurized gasoline and diesel, a waste solvent containing sulfones is also generated, and the method for ultrasonic oxidation desulfurization of gasoline and diesel also includes the step of recovering the extractant from the waste solvent containing sulfones.

[0022] By adopting the above technical scheme, the extractant is recovered from the sulfone-containing waste solvent, and the recovered extractant is put into the step of countercurrent extraction of gasoline or diesel. The recovered extractant can again extract and separate the sulfoxides and sulfones in the subsequently introduced gasoline or diesel, so as to realize the recycling of the extractant, further save costs and improve environmental protection.

[0023] Optionally, the step of recovering the extractant includes: dehydrating the sulfone-containing waste solvent at 110-130°C and 8-12kpaA to obtain circulating water; recovering the dehydrated sulfone-containing waste solvent at 90-120°C and 1-5kpaA to obtain a circulating solvent; and mixing the circulating water and the circulating solvent to form an extractant, which is then reintroduced into the step of countercurrent extraction of gasoline and diesel.

[0024] By adopting the above technical solution, the sulfone-containing waste solvent is first subjected to negative pressure distillation to dehydrate the sulfone-containing waste solvent and obtain circulating water; since the boiling point of the extractant is higher than that of water, the dehydrated sulfone-containing waste solvent is then passed through a 90-120°C, 1-5kpaA environment for negative pressure distillation to obtain a circulating solvent. After the circulating water and the circulating solvent are mixed to form an extractant, the sulfoxide or sulfone in gasoline or diesel is continuously extracted and separated to realize the recycling of the extractant, further saving costs and improving environmental protection.

[0025] Optionally, in the above step 2, the mixed liquid is mixed with gasoline and diesel and heated to 50-60° C., and an ultrasonic oxidation reaction is carried out under an ultrasonic wave of 15-25 KHz to obtain preformed oil.

[0026] Optionally, in the above step 2, the mixed liquid is mixed with gasoline and diesel and heated to 60-70° C., and an ultrasonic oxidation reaction is carried out under an ultrasonic wave of 15-25 KHz to obtain preformed oil.

[0027] In the second aspect, the present application provides a desulfurization system for a gasoline and diesel ultrasonic oxidation desulfurization method using the following technical solutions:

[0028] A desulfurization system for ultrasonic oxidation desulfurization of gasoline and diesel, comprising a pipeline mixer for introducing and mixing an oxidant and an organic acid catalyst, a gasoline and diesel heater for heating gasoline and diesel, an ultrasonic reactor for oxidation reaction, a phase separation tank for phase separation of preformed oil, and an extraction tower for countercurrent extraction of gasoline and diesel containing sulfone and sulfoxide, the feed inlet of the pipeline mixer being provided with an oxidant pump and a catalyst pump, the discharge port of the pipeline mixer being provided with a gasoline and diesel feed pump; the ultrasonic reactor being connected to the pipeline mixer through a pipeline, the phase separation tank being connected to the ultrasonic reactor through a pipeline, and the extraction tower being connected to the phase separation tank through a pipeline.

[0029] By adopting the above technical scheme, the oxidant pump, catalyst pump and gasoline and diesel feed pump respectively accurately control the flow rate of the oxidant solution, organic acid catalyst solution and gasoline or diesel, so that the flow rate of the oxidant solution is 3-8% of the flow rate of gasoline or diesel, and the flow rate of the organic acid catalyst solution is 1-3% of the flow rate of gasoline or diesel. The oxidant solution and the organic acid catalyst solution are first introduced into the pipeline mixer for mixed reaction to generate peroxy acid, and at the same time, the gasoline or diesel heater heats the gasoline or diesel, and the peroxy acid and the heated gasoline or diesel are mixed and introduced into the ultrasonic reactor for ultrasonic oxidation reaction, and then the organic acid catalyst and gasoline or diesel are phase-separated by the phase separation tank. The gasoline or diesel after phase separation is introduced into the extraction tower for countercurrent extraction.

[0030] Optionally, the extraction tower has a first outlet and a second inlet located at the top and a second outlet and a first inlet located at the bottom. The desulfurization system also includes a desolventizing tower for removing the solvent in the desulfurized gasoline and diesel, and the desolventizing tower is connected to the first outlet pipeline of the extraction tower.

[0031] By adopting the above technical solution, the desulfurized gasoline and diesel are introduced into the desolventizing tower from the first outlet of the extraction tower to remove a small amount of solvent in the desulfurized gasoline and diesel to obtain desolventized desulfurized gasoline and diesel, thereby improving the quality of the product oil.

[0032] Optionally, the desulfurization system also includes a recovery device for recovering the extractant, and the recovery device includes a waste solvent tank, a solvent dehydration tower and a solvent recovery tower; the waste solvent tank is connected to the second outlet of the extraction tower through a pipeline, the solvent dehydration tower is connected to the waste solvent tank through a pipeline, the solvent recovery tower is connected to the solvent dehydration tower through a pipeline, and the solvent dehydration tower and the solvent recovery tower are both connected to the second inlet of the extraction tower through pipelines.

[0033] By adopting the above technical solution, the sulfone-containing waste solvent is introduced into the waste solvent tank from the second outlet of the extraction tower, and then introduced into the solvent dehydration tower and the solvent recovery tower in sequence from the waste solvent tank to dehydrate and desolventize the sulfone-containing waste solvent to obtain circulating water and circulating solvent. The circulating water and circulating solvent are mixed and then introduced into the extraction tower again to realize the recycling of the extractant.

[0034] Optionally, the solvent recovery tower is connected to a tail gas combustion system via a pipeline, and the tail gas combustion system is used to process non-condensable gas of the raw materials gasoline and diesel.

[0035] By adopting the above technical solution, a small amount of non-condensable gas in gasoline or diesel contains harmful gases such as methane or flammable and explosive gases. The exhaust gas combustion system burns the above gases before discharging them to ensure production safety and reduce pollution to the environment.

[0036] Optionally, the bottom of the solvent recovery tower is connected to an extraction oil desolventizing tower via a pipeline.

[0037] By adopting the above technical scheme, extracted oil is usually produced at the bottom of the solvent recovery tower, and the extracted oil is passed into the extraction oil desolventizing tower to remove the residual solvent in the extracted oil. The extracted oil after the solvent is removed can be produced as a by-product, thereby improving industrial production efficiency.

[0038] In summary, the present application includes at least one of the following beneficial technical effects:

[0039] 1. A relatively appropriate amount of peroxyacid flow can oxidize the thiophene sulfur contained in gasoline or diesel into sulfoxides or sulfones as comprehensively as possible, thereby improving the oxidative desulfurization effect of gasoline or diesel and making the amount of peroxyacid after ultrasonic oxidation as small as possible, thereby reducing the waste of oxidants and the difficulty of recovering organic acid catalysts;

[0040] 2. The aqueous phase of the organic acid catalyst is dried and dehydrated with a desiccant, and the dehydrated organic acid catalyst is reintroduced into the mixed solution for the reaction to generate the peroxy acid. The organic acid catalyst can react with the oxidant again to generate the peroxy acid, so as to realize the recycling of the organic acid catalyst, save costs and improve environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the process of the desulfurization system in the embodiment of the present application.

[0042] Figure numerals: 1. pipeline mixer; 11. oxidant pump; 12. catalyst pump; 121. catalyst circulation pump; 2. gasoline and diesel feed pump; 21. gasoline and diesel heater; 3. ultrasonic reactor; 4. phase separation tank; 41. catalyst water remover; 5. extraction tower; 6. desolventizing tower; 7. recovery device; 71. waste solvent tank; 72. solvent dehydration tower; 73. solvent recovery tower; 8. tail gas combustion system; 9. extraction oil desolventizing tower. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1 This application is described in further detail.

[0044] The present application discloses a desulfurization system for a gasoline and diesel ultrasonic oxidation desulfurization method. Figure 1The desulfurization system of the gasoline and diesel ultrasonic oxidation desulfurization method comprises a pipeline mixer 1, a gasoline and diesel heater 21, an ultrasonic reactor 3, a phase separation tank 4 and an extraction tower 5. The pipeline mixer 1 is connected to an oxidant pump 11 and a catalyst pump 12. The discharge ports of the oxidant pump 11 and the catalyst pump 12 are both connected to the feed port of the pipeline mixer 1. The pipeline mixer 1 is used to introduce and mix the oxidant and the organic acid catalyst. The discharge port of the pipeline mixer 1 is connected to a gasoline and diesel feed pump 2 through a pipeline.

[0045] The pipeline mixer 1 is connected to the feed end of the ultrasonic reactor 3 through a pipeline, and the pipeline between the pipeline mixer 1 and the ultrasonic reactor 3 is connected to a gasoline and diesel feed pump 2.

[0046] The ultrasonic reactor 3 and the gasoline and diesel feed pump 2 are connected to the gasoline and diesel heater 21 through a pipeline. The gasoline and diesel heater 21 is used to heat the mixture of gasoline, diesel and peroxy acid to 50-70° C. to obtain preformed oil.

[0047] The phase separation tank 4 is used for phase separation of the preformed oil. The phase separation tank 4 is provided with an inlet, a light phase outlet and a heavy phase outlet. The inlet of the phase separation tank 4 is connected to the outlet of the ultrasonic reactor 3 through a pipeline. The heavy phase outlet of the phase separation tank 4 is connected to the inlet of the catalyst dehydrator 41 through a pipeline. The catalyst dehydrator 41 is filled with a desiccant. In the embodiment of the present application, the desiccant is anhydrous magnesium sulfate of 80-100 meshes. The outlet of the catalyst dehydrator 41 is connected to the catalyst circulation pump 121 through a pipeline, and the outlet of the catalyst circulation pump 121 is connected to the feed end of the catalyst pump 12 through a pipeline.

[0048] The extraction tower 5 is provided with a first outlet and a second inlet located at the upper part of the extraction tower 5, and a second outlet and a first inlet located at the lower part of the extraction tower 5, and the light phase discharge port of the phase separation tank 4 is connected to the first inlet of the extraction tower 5 through a pipeline. The first outlet of the extraction tower 5 is connected to a desolventizing tower 6 through a pipeline, and the desolventizing tower 6 is used to remove the solvent in the desulfurized gasoline and diesel.

[0049] The desulfurization system also includes a recovery device 7, which is used to recover the extractant. The recovery device 7 includes a waste solvent tank 71, a solvent dehydration tower 72 and a solvent recovery tower 73, and the waste solvent tank 71 is connected to the second outlet of the extraction tower 5 through a pipeline. The solvent dehydration tower 72 is provided with a feed inlet, a steam outlet and a discharge port, and the solvent recovery tower 73 is also provided with a feed inlet, a steam outlet and a discharge port. The feed inlet of the solvent dehydration tower 72 is connected to the waste solvent tank 71 through a pipeline, and the feed inlet of the solvent recovery tower 73 is connected to the discharge port of the solvent dehydration tower 72 through a pipeline, and the steam outlets of the solvent dehydration tower 72 and the solvent recovery tower 73 are both connected to the second inlet of the extraction tower 5 through a pipeline.

[0050] The bottom of the solvent recovery tower 73 is connected to an extraction oil desolventizing tower 9 through a pipeline. Extraction oil is usually produced at the bottom of the solvent recovery tower 73, and the extraction oil is passed into the extraction oil desolventizing tower 9 to remove the residual solvent in the extraction oil. The extraction oil after the solvent is removed can be produced as a by-product to improve the industrial production efficiency.

[0051] The solvent recovery tower 73 is connected to the tail gas combustion system 8 through a pipeline. The solvent gas in the vacuum system will dissolve in water. A small amount of non-condensable gas in the raw gasoline and diesel is not easily soluble in water, and the non-condensable gas contains harmful gases such as methane or flammable and explosive gases. The tail gas combustion system 8 burns the above gases before discharging them to ensure production safety and reduce pollution to the environment.

[0052] 1. Embodiment:

[0053] Examples 1-7 are directed to the ultrasonic oxidation desulfurization of diesel.

[0054] Embodiment 1:

[0055] The ultrasonic oxidation desulfurization method of diesel in this embodiment comprises:

[0056] A hydrogen peroxide solution (mass fraction of 30%) is introduced into the pipeline mixer 1 through an oxidant feed pump, and a formic acid catalyst solution (mass fraction of 85%) is introduced into the pipeline mixer 1 through a catalyst feed pump, and diesel is introduced into the pipeline of the desulfurization system through a gasoline and diesel feed pump 2. The flow rate of diesel is 60 kg / h, the flow rate of hydrogen peroxide solution is 1.8 kg / h, and the flow rate of formic acid catalyst solution is 0.6 kg / h.

[0057] The hydrogen peroxide solution and the formic acid catalyst solution react to generate peracid. The peracid and diesel are mixed and heated to 55° C. by a gasoline and diesel heater 21. The peracid and diesel are then introduced into an ultrasonic reactor 3. The ultrasonic frequency in the ultrasonic reactor 3 is 20 KHz. The peracid and diesel are ultrasonically oxidized to obtain preformed oil and an aqueous phase containing an organic acid catalyst.

[0058] The preformed oil and the aqueous phase containing the organic acid catalyst are introduced into the phase separation tank 4 for phase separation. The aqueous phase containing the organic acid catalyst is introduced into the catalyst dehydrator 41, and is dried and dehydrated by 100 mesh anhydrous magnesium sulfate. The dehydrated organic acid catalyst is introduced into the catalyst feed pipeline by the catalyst circulation pump 121 to realize recycling.

[0059] The water-saturated magnesium sulfate is passed through saturated steam at 180°C and 1Mpa, and the magnesium sulfate is heated to 160°C for drying and dehydration to obtain anhydrous magnesium sulfate, which is then re-introduced into the aqueous phase containing the organic acid catalyst to achieve the recycling of the anhydrous magnesium sulfate.

[0060] The extractant is an NMP aqueous solution, which enters the extraction tower 5 from the second inlet at the top of the extraction tower 5, and the diesel containing sulfone and sulfoxide enters the extraction tower 5 through the first inlet at the bottom of the extraction tower 5, so as to perform countercurrent extraction on the diesel containing sulfone and sulfoxide to obtain desulfurized diesel. The desulfurized diesel is then passed into a desolventizing tower 6 with a temperature parameter of 100°C and a pressure parameter of 1kpaA for desolventizing to obtain desolventized desulfurized diesel.

[0061] The sulfone-containing waste solvent from the second outlet of the extraction tower 5 is passed into the waste solvent tank 71, and then passed into the solvent dehydration tower 72 for dehydration. The temperature parameter in the solvent dehydration tower 72 is 120°C and the pressure parameter is 10kpaA to obtain circulating water. The dehydrated sulfone-containing waste solvent is passed into the solvent recovery tower 73. The temperature parameter of the solvent recovery tower 73 is 110°C and the pressure parameter is 3kpaA to obtain a circulating solvent. The circulating water and the circulating solvent are mixed to form an extractant, and then the extractant is passed to the solvent recovery tower 73 for heat exchange with the solvent vapor to 70°C, and then the extractant is re-passed into the extraction tower 5 to realize the recycling of the extractant.

[0062] Finally, the non-condensable gas produced in the solvent recovery tower 73 is introduced into the exhaust gas combustion system 8 for exhaust gas treatment; and the extracted oil produced from the bottom of the solvent recovery tower 73 is introduced into the extraction oil desolventizing tower 9, the temperature parameters of the extraction oil desolventizing tower 9 are 130°C and the pressure parameters are 1kpaA, so that the extraction oil can be produced as a by-product.

[0063] Embodiment 2:

[0064] The ultrasonic oxidation desulfurization method for diesel in this embodiment is different from that in Embodiment 1 in that the flow rate of the hydrogen peroxide solution is 3 kg / h, and the flow rate of the formic acid catalyst solution is 1.2 kg / h.

[0065] Embodiment 3:

[0066] The ultrasonic oxidation desulfurization method for diesel in this embodiment is different from that in Embodiment 1 in that the flow rate of the hydrogen peroxide solution is 4.8 kg / h, and the flow rate of the formic acid catalyst solution is 1.8 kg / h.

[0067] Embodiment 4:

[0068] The difference between the ultrasonic oxidation desulfurization method of diesel in this embodiment and that in Embodiment 2 is that the temperature parameter in the solvent dehydration tower 72 is 110° C. and the pressure parameter is 8 kPaA.

[0069] Embodiment 5:

[0070] The difference between the ultrasonic oxidation desulfurization method of diesel in this embodiment and that in Embodiment 2 is that the temperature parameter in the solvent dehydration tower 72 is 130° C. and the pressure parameter is 12 kPaA.

[0071] Embodiment 6:

[0072] The difference between the ultrasonic oxidation desulfurization method of diesel in this embodiment and that in Embodiment 2 is that the temperature parameter of the solvent recovery tower 73 is 90° C. and the pressure parameter is 1 kPaA.

[0073] Embodiment 7:

[0074] The difference between the ultrasonic oxidation desulfurization method of diesel in this embodiment and that in Embodiment 2 is that the temperature parameter of the solvent recovery tower 73 is 120° C. and the pressure parameter is 5 kPaA.

[0075] Examples 8-14 are directed to the ultrasonic oxidation desulfurization of gasoline.

[0076] Embodiment 8:

[0077] The ultrasonic oxidation desulfurization method of gasoline in this embodiment comprises:

[0078] A hydrogen peroxide solution (mass fraction of 30%) is introduced into the pipeline mixer 1 through an oxidant feed pump, and a formic acid catalyst solution (mass fraction of 85%) is introduced into the pipeline mixer 1 through a catalyst feed pump, and gasoline is introduced into the pipeline of the desulfurization system through a gasoline and diesel feed pump 2. The flow rate of gasoline is 60 kg / h, the flow rate of hydrogen peroxide solution is 1.8 kg / h, and the flow rate of formic acid catalyst solution is 0.6 kg / h.

[0079] The hydrogen peroxide solution and the formic acid catalyst solution react to generate peracid. The peracid and gasoline are mixed and heated to 55° C. by a gasoline and diesel heater 21. The peracid and gasoline are then introduced into an ultrasonic reactor 3. The ultrasonic frequency in the ultrasonic reactor 3 is 20 KHz. The peracid and gasoline are ultrasonically oxidized to obtain preformed oil and an aqueous phase containing an organic acid catalyst.

[0080] The preformed oil and the aqueous phase containing the organic acid catalyst are introduced into the phase separation tank 4 for phase separation. The aqueous phase containing the organic acid catalyst is introduced into the catalyst dehydrator 41, and is dried and dehydrated by 100 mesh anhydrous magnesium sulfate. The dehydrated organic acid catalyst is introduced into the catalyst feed pipeline by the catalyst circulation pump 121 to realize recycling.

[0081] The water-saturated magnesium sulfate is passed through saturated steam at 180°C and 1Mpa, and the magnesium sulfate is heated to 160°C for drying and dehydration to obtain anhydrous magnesium sulfate, which is then re-introduced into the aqueous phase containing the organic acid catalyst to achieve the recycling of the anhydrous magnesium sulfate.

[0082] The extractant is an NMP aqueous solution, which enters the extraction tower 5 from the second inlet at the top of the extraction tower 5, and the gasoline containing sulfone and sulfoxide enters the extraction tower 5 through the first inlet at the bottom of the extraction tower 5, so as to perform countercurrent extraction on the gasoline containing sulfone and sulfoxide to obtain desulfurized gasoline. The desulfurized gasoline is then passed into a desolventizing tower 6 with a temperature parameter of 100°C and a pressure parameter of 1kpaA for desolventizing to obtain desolventized desulfurized gasoline.

[0083] The sulfone-containing waste solvent from the second outlet of the extraction tower 5 is passed into the waste solvent tank 71, and then passed into the solvent dehydration tower 72 for dehydration. The temperature parameter in the solvent dehydration tower 72 is 120°C and the pressure parameter is 10kpaA to obtain circulating water. The dehydrated sulfone-containing waste solvent is passed into the solvent recovery tower 73. The temperature parameter of the solvent recovery tower 73 is 110°C and the pressure parameter is 3kpaA to obtain a circulating solvent. The circulating water and the circulating solvent are mixed to form an extractant, and then the extractant is passed to the solvent recovery tower 73 for heat exchange with the solvent vapor to 70°C, and then the extractant is re-passed into the extraction tower 5 to realize the recycling of the extractant.

[0084] Finally, the non-condensable gas produced in the solvent recovery tower 73 is introduced into the exhaust gas combustion system 8 for exhaust gas treatment; and the extracted oil produced from the bottom of the solvent recovery tower 73 is introduced into the extraction oil desolventizing tower 9, the temperature parameters of the extraction oil desolventizing tower 9 are 130°C and the pressure parameters are 1kpaA, so that the extraction oil can be produced as a by-product.

[0085] Embodiment 9:

[0086] The difference between the ultrasonic oxidation desulfurization method for gasoline in this embodiment and that in Embodiment 8 is that the flow rate of the hydrogen peroxide solution is 3 kg / h, and the flow rate of the formic acid catalyst solution is 1.2 kg / h.

[0087] Embodiment 10:

[0088] The difference between the method for ultrasonic oxidation desulfurization of gasoline in this embodiment and that in Embodiment 8 is that the flow rate of the hydrogen peroxide solution is 4.8 kg / h, and the flow rate of the formic acid catalyst solution is 1.8 kg / h.

[0089] Embodiment 11:

[0090] The difference between the ultrasonic oxidation desulfurization method of gasoline in this embodiment and that in Embodiment 9 is that the temperature parameter in the solvent dehydration tower 72 is 110° C. and the pressure parameter is 8 kPaA.

[0091] Embodiment 12:

[0092] The difference between the ultrasonic oxidation desulfurization method of gasoline in this embodiment and that in Embodiment 9 is that the temperature parameter in the solvent dehydration tower 72 is 130° C. and the pressure parameter is 12 kPaA.

[0093] Embodiment 13:

[0094] The difference between the ultrasonic oxidation desulfurization method of gasoline in this embodiment and that in Embodiment 9 is that the temperature parameter of the solvent recovery tower 73 is 90° C. and the pressure parameter is 1 kPaA.

[0095] Embodiment 14:

[0096] The difference between the ultrasonic oxidation desulfurization method of gasoline in this embodiment and that in Embodiment 9 is that the temperature parameter of the solvent recovery tower 73 is 120° C. and the pressure parameter is 5 kPaA.

[0097] 2. Performance testing:

[0098] 1) The desulfurized and desolventized diesel prepared by the preparation method in Examples 1-7 and the desulfurized and desolventized gasoline prepared by the preparation method in Examples 8-14 were tested in accordance with "GB / T11140-2008 Determination of sulfur content of petroleum products - Wavelength dispersive X-ray fluorescence spectrometry" to obtain the sulfur content of the desulfurized and desolventized diesel and the desulfurized and desolventized gasoline, respectively, and the unit of the sulfur content is ppm (parts per million).

[0099] 2) In Examples 1-7 of desulfurization and desolventization of diesel and Examples 8-14 of desulfurization and desolventization of gasoline, equal amounts of aqueous phase containing organic acid catalyst were collected at the heavy phase outlet of the phase separation tank, and the peroxyacid content in the aqueous phase containing the organic acid catalyst was determined by iodine titration.

[0100] The above performance test results are shown in Table 1 and Table 2:

[0101] Table 1 Performance test results of desulfurized and desolventized diesel of Examples 1-7

[0102]

[0103]

[0104] Table 2 Performance test results of desulfurized and desolventized gasoline of Examples 8-14

[0105]

[0106] 3. Results analysis and summary:

[0107] Combining Examples 1-14 and Tables 1 and 2, it can be seen that the sulfur contents in the desulfurized desolventized diesel obtained in Example 1 and the desulfurized desolventized gasoline obtained in Example 8 are 12ppm and 11ppm, respectively, the desulfurized desolventized diesel obtained in Example 2 and Example 3 are 6ppm and 6ppm, respectively, and the sulfur contents in the desulfurized desolventized gasoline obtained in Example 9 and Example 10 are 5ppm and 5ppm, respectively. It can be seen from the above that the desulfurized desolventized diesel obtained in Example 2 and Example 3 is much lower than the sulfur content in Example 1, and the sulfur content in the desulfurized desolventized gasoline obtained in Example 9 and Example 10 is much lower than the sulfur content in Example 8.

[0108] However, the peroxy acid contents in the aqueous phase containing the organic acid catalyst in the process of preparing desulfurized desolventized diesel and desulfurized desolventized gasoline in Example 3 and Example 10 were 2.3% and 2.55%, respectively. The peroxy acid contents in the aqueous phase containing the organic acid catalyst in the process of preparing desulfurized desolventized diesel and desulfurized desolventized gasoline in Example 2 and Example 9 were 0.83% and 0.76%, respectively.

[0109] It can be seen from the above that the peroxy acid content generated in the process of preparing desulfurized and desolventized diesel in Example 3 is higher than that in Example 2, and the peroxy acid content generated in the process of preparing desulfurized and desolventized gasoline in Example 10 is higher than that in Example 9. Therefore, although Examples 2-3 and Examples 9-10 have greatly reduced the sulfur content in desulfurized and desolventized diesel and desulfurized and desolventized gasoline, there is more peroxy acid remaining in Example 3 and Example 10, that is, the amount of oxidant wasted is relatively large, and the difficulty of recovering the organic acid catalyst in Example 3 and Example 10 is increased.

[0110] In summary, the mass flow ratio of the oxidant solution, the organic acid catalyst solution and the gasoline and diesel in Examples 2 and 9 can improve the oxidative desulfurization effect of gasoline and diesel while reducing the waste of the oxidant and the difficulty of recovering the organic acid catalyst.

[0111] The temperature parameters and pressure parameters in the solvent dehydration tower and the temperature parameters and pressure parameters in the solvent recovery tower in Examples 4-7 are different from those in Example 2, and the temperature parameters and pressure parameters in the solvent dehydration tower and the temperature parameters and pressure parameters in the solvent recovery tower in Examples 11-14 are different from those in Example 9. As shown in Table 1, the sulfur content in the desulfurized desolventized diesel and desulfurized desolventized gasoline prepared in Examples 4-7 is greater than that in Example 2, and the sulfur content in the desulfurized desolventized diesel and desulfurized desolventized gasoline prepared in Examples 11-14 is greater than that in Example 9, so the desulfurization effect of Example 4-7 on gasoline and diesel is worse than that of Example 2, and the desulfurization effect of Example 11-14 on gasoline and diesel is worse than that of Example 9.

[0112] From the above, it can be seen that the temperature parameters in the solvent dehydration tower in Example 2 and Example 9 are both 120°C and the pressure parameters are both 10kpaA, and the temperature parameters in the solvent dehydration tower are both 110°C and the pressure parameters are both 3kpaA. The above parameters can make the extractant in the sulfone-containing waste solvent more and more efficiently recovered and recycled back to the extraction tower, so that the extractant in the extraction tower can be kept in a sufficient state, so that the sulfones in the gasoline and diesel passed into the extraction tower can be extracted and separated more fully and thoroughly, so as to improve the desulfurization effect of gasoline and diesel.

[0113] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for ultrasonic oxidation desulfurization of gasoline and diesel, characterized in that: include: S1, mixing an oxidant solution and an organic acid catalyst solution to form a mixed solution, wherein the oxidant reacts with the organic acid catalyst to form a peroxy acid; S2, mixing the mixed liquid with gasoline and diesel and heating them to 50-70°C, and performing ultrasonic oxidation reaction under 15-25KHz ultrasonic wave to obtain preformed oil; wherein the mass flow ratio of the oxidant solution, the organic acid catalyst solution and the gasoline and diesel is (0.03-0.08): (0.01-0.03): 1; S3, performing phase separation treatment on the preformed oil, wherein the upper layer is gasoline and diesel containing sulfone and sulfoxide, and the lower layer is an aqueous phase containing the organic acid catalyst; S4, recovering the organic acid catalyst, and performing countercurrent extraction on the gasoline and diesel to obtain desulfurized gasoline and diesel; While the gasoline and diesel are subjected to countercurrent extraction to obtain desulfurized gasoline and diesel, a sulfone-containing waste solvent is also generated. The method for ultrasonic oxidation desulfurization of gasoline and diesel also includes a step of recovering an extractant from the sulfone-containing waste solvent. The step of recovering the extractant includes: dehydrating the sulfone-containing waste solvent at 110-130° C. and 8-12 kPaA to obtain circulating water; The mass fraction of the oxidant solution is 30%, and the mass fraction of the organic acid catalyst solution is 85%; The oxidant is hydrogen peroxide, and the organic acid is formic acid.

2. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 1, characterized in that: The method for recovering the organic acid catalyst comprises: The aqueous phase containing the organic acid catalyst is dried and dehydrated by a desiccant, and the dehydrated organic acid catalyst is formulated into a solution and then introduced into the mixed solution in step S1.

3. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 2, characterized in that: The desiccant is passed through saturated steam at 170-190° C. and 0.5-2 MPa, and the desiccant is heated to 150-170° C. to perform the drying and dehydration treatment step, and the dehydrated desiccant is reintroduced into the aqueous phase containing the organic acid catalyst.

4. The method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 1, characterized in that: The invention also comprises the following steps of post-processing the desulfurized gasoline and diesel: The desulfurized gasoline and diesel are subjected to solvent removal at 90-110° C. and 0.5-1.5 kPaA to obtain desolventized desulfurized gasoline and diesel.

5. The method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 1, characterized in that: The step of recovering the extractant also includes: recovering the dehydrated sulfone-containing waste solvent under an environment of 90-120° C. and 1-5 kPaA to obtain a circulating solvent; and then mixing the circulating water and the circulating solvent to form an extractant, which is then reintroduced into the step of countercurrent extraction of gasoline and diesel.

6. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to any one of claims 1 to 5, characterized in that: The desulfurization system of the method for ultrasonic oxidation desulfurization of gasoline and diesel comprises a pipeline mixer (1) for introducing and mixing an oxidant and an organic acid catalyst, a gasoline and diesel heater (21) for heating gasoline and diesel, an ultrasonic reactor (3) for performing an oxidation reaction, a phase separation tank (4) for performing phase separation treatment on preformed oil, and an extraction tower (5) for performing countercurrent extraction on gasoline and diesel containing sulfone and sulfoxide, which are sequentially connected and arranged. The feed port of the pipeline mixer (1) is provided with an oxidant pump (11) and a catalyst pump (12), and the discharge port of the pipeline mixer (1) is provided with a gasoline and diesel feed pump (2); the ultrasonic reactor (3) is connected to the pipeline mixer (1) via a pipeline, the phase separation tank (4) is connected to the ultrasonic reactor (3) via a pipeline, and the extraction tower (5) is connected to the phase separation tank (4) via a pipeline.

7. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 6, characterized in that: The extraction tower (5) has a first outlet and a second inlet located at the top, and a second outlet and a first inlet located at the bottom. The desulfurization system also includes a desolventizing tower (6) for removing the solvent in the desulfurized gasoline and diesel. The desolventizing tower (6) is connected to the first outlet pipeline of the extraction tower (5).

8. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 6, characterized in that: The desulfurization system further comprises a recovery device (7) for recovering the extractant, the recovery device (7) comprising a waste solvent tank (71), a solvent dehydration tower (72) and a solvent recovery tower (73); the waste solvent tank (71) is connected to the second outlet of the extraction tower (5) via a pipeline, the solvent dehydration tower (72) is connected to the waste solvent tank (71) via a pipeline, the solvent recovery tower (73) is connected to the solvent dehydration tower (72) via a pipeline, and the solvent dehydration tower (72) and the solvent recovery tower (73) are both connected to the second inlet of the extraction tower (5) via pipelines.

9. A method for ultrasonic oxidation desulfurization of gasoline and diesel according to claim 8, characterized in that: The solvent recovery tower (73) is connected to a tail gas combustion system (8) via a pipeline, and the tail gas combustion system (8) is used to process non-condensable gas of the raw materials gasoline and diesel.

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