Cleaning system and method for membrane emulsification equipment

Abstract

The invention discloses a cleaning system of membrane emulsification equipment, which comprises an emulsifier system, a heat source circulation system and a cleaning system, the cleaning system comprises an organic solvent tank body system, an organic solvent filtering circulating system, an organic solvent filter body system, an organic solvent oil supply circulating system, an organic solvent backflow circulating system, a heating system and a pollution discharge and steam exhaust system. Compared with the prior art, a cleaning program is cut in or cut out by monitoring the deviation of a transmembrane pressure difference value of the emulsifier to a set value, so that intelligent cleaning is realized; the non-ionic surfactant is adopted as a cleaning medium, the surface tension of the film is reduced, damage to the film and equipment is reduced, and equipment cleaning is completed.

Description

Technical Field

[0001] The invention relates to the technical field of heavy oil film emulsification, and in particular to a cleaning system and method for film emulsification equipment. Background Art

[0002] Heavy oil resources are very abundant worldwide, with reserves of about 6 to 7 times that of conventional crude oil. As crude oil prices rise, crude oil becomes heavier and inferior, and the demand for light oil products increases. It is becoming more and more urgent to refine heavy oil into light oil products such as gasoline and diesel. Heavy oil energy is one of the important energy sources in my country, and heavy oil membrane emulsification technology is one of the methods to improve the utilization rate of heavy oil.

[0003] During the heavy oil emulsification process, due to the fluctuation of production conditions, heavy oil reverse osmosis will occur, resulting in blockage of the microchannels of the emulsified medium, a decrease in emulsification flux, and a further increase in the transmembrane pressure difference (the pressure difference between the raw material side and the permeate side), which will cause the system to shut down due to overpressure and reduce equipment utilization. Therefore, equipment cleaning is required during production operation. The cleaning of the membrane surface can be divided into in-situ cleaning and non-in-situ cleaning according to whether the membrane assembly is disassembled and adjusted during cleaning; according to the cleaning method, it can be divided into physical cleaning and chemical cleaning. Physical cleaning mainly uses water and gas flushing and purging methods, which have a short duration and can only remove large particles attached to the membrane surface; chemical cleaning generally uses acid and alkali cleaning methods, using high-strength alkaline solutions such as sodium hydroxide and sodium carbonate to soften, loosen, and disperse sediments or use acidic solutions to remove surface oxides. Both are prone to produce chemical waste liquid, which is highly damaging to membrane emulsification equipment, has high operating risks for workers, and requires shutdown. During the heavy oil emulsification process, due to its large number of impurities and complex components, it is easy to cause blockage of membrane pores. Traditional cleaning methods cannot meet normal production needs. Summary of the invention

[0004] The purpose of the present invention is to address the problem that during the emulsification process of heavy oil, a large number of impurities are easily generated, and the impurity components are complex, which can easily cause membrane pore blockage. The existing physical membrane cleaning method can only remove larger particles attached to the membrane surface; the chemical cleaning method is used to clean the membrane, which is likely to produce chemical waste liquid, which is highly damaging to the membrane emulsification equipment, has high operating risks for workers, and requires shutdown, increasing operating costs. In view of this deficiency, a cleaning system and method for membrane emulsification equipment are proposed.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A method for cleaning a membrane emulsification device comprises the following steps: S1. Preset the threshold of the transmembrane pressure difference in the emulsifier and set the floating range of the transmembrane pressure difference; S2, obtaining the transmembrane pressure difference in the current emulsifier; S3, judging whether the current transmembrane pressure difference is greater than or equal to the upper limit of the threshold floating range, if the current transmembrane pressure difference is greater than or equal to the upper limit, performing the cleaning procedure of step S4; S4, supplying an organic solvent into the emulsifier for circulation, and after cleaning for a first time, adding a surfactant to the organic solvent, soaking the emulsifier, and then continuing to rinse for a second time; S5. After cleaning is completed, determine whether the transmembrane pressure difference after cleaning is within the floating range of the threshold. If the transmembrane pressure difference after cleaning is less than the upper limit of the floating range, the cleaning is completed. Otherwise, continue the cleaning procedure of step S4 until the transmembrane pressure difference is less than the upper limit of the floating range.

[0006] As a further preferred embodiment of the present invention, the first time is 2h-3h; the soaking time is 30min-50min; and the second time is 10min-20min.

[0007] As a further preference of the present invention, the surfactant is a nonionic surfactant, and the mass ratio of the surfactant to the organic solvent is 0.1-1:1.

[0008] As further preferred embodiment of the present invention, the nonionic surfactant is a polymer of fatty alcohol or fatty acid and ethylene oxide or acrylic acid.

[0009] As a further preferred embodiment of the present invention, the nonionic surfactant is a Tween or Span surfactant.

[0010] As a further preferred embodiment of the present invention, after the washing is completed, the organic solvent is recovered and filtered and purified.

[0011] A cleaning system for membrane emulsification equipment, comprising: Membrane emulsification system, used for membrane emulsification treatment of heavy oil; An organic solvent tank, used for storing organic solvents; An organic solvent filter, connected to the organic solvent tank, is used to filter the organic solvent to remove impurities; An organic solvent feeding device, used for feeding the organic solvent in the organic solvent tank into the organic solvent filter; An organic solvent circulation tank, connected to the membrane emulsification system, is used to store the organic solvent during the cleaning process; The organic solvent circulation tank is also connected to the organic solvent tank through a valve; A porous ceramic membrane is used as an emulsifying medium in the membrane emulsification system, and a pressure measuring unit is also included in the membrane emulsification system for detecting the trans-membrane pressure difference on both sides of the porous ceramic membrane.

[0012] As a further preferred embodiment of the present invention, the organic solvent feeding device includes a plunger pump.

[0013] As a further preferred embodiment of the present invention, a metal filter element is used as a filter unit in the organic solvent filter, and the pore size is 0.1-5 μm.

[0014] As a further preferred embodiment of the present invention, it further comprises: a steam heating system connected to the organic solvent tank and / or the organic solvent filter, for heating the organic solvent tank and / or the organic solvent filter; A sewage discharge device is provided at the bottom of the organic solvent tank and the organic solvent filter; The organic solvent tank is filled with diesel; The organic solvent tank is also provided with a surfactant feeding port for adding the surfactant into the organic solvent tank; The organic solvent tank is a jacketed pressure vessel.

[0015] The cleaning system and method of a membrane emulsification device proposed by the present invention have the following beneficial effects compared with the prior art: 1. The present invention switches in or out of the cleaning procedure by monitoring the deviation of the transmembrane pressure difference of the emulsifier from the set value; 2. The present invention uses a non-ionic surfactant as a cleaning medium to reduce the surface tension of the membrane, reduce damage to the membrane and equipment, and complete equipment cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention; The meanings of the reference numerals in the figure are as follows: 01, organic solvent tank, 10, filter circulation pipe, 11, plunger pump inlet valve, 12, discharge valve, 13, plunger pump, 14, plunger pump outlet check valve, 15, stop valve, 16, pressure instrument, 17, filter inlet valve, 20, organic solvent filter, 30, oil supply circulation pipe, 31, filter outlet valve, 40, organic solvent reflux pipeline, 43, inlet electric valve, 50, heating pipeline, 51, solvent tank inlet stop valve, 52, filter steam inlet solenoid valve, 60, first sewage valve, 61, regular sewage valve, 62, first throttling orifice, 63, second sewage valve, 64, exhaust valve, 65, second throttling orifice, 66, third sewage valve, 70, skid-mounted reserved flange interface, 8, surfactant feeding port. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1: Combination Figure 1A cleaning system for membrane emulsification equipment includes an emulsifier system, a heat source circulation system and a cleaning system, wherein the emulsifier system includes an emulsifier (the emulsifier here uses a porous ceramic membrane for membrane emulsification treatment, which can be carried out by referring to the prior art, and the heavy oil flows through one side of the porous ceramic membrane, permeates through the membrane pores, and contacts with the continuous phase solvent on the permeation side to obtain emulsified heavy oil), and the cleaning system includes an organic solvent tank 01 main body system, an organic solvent filtration circulation system, an organic solvent filter 20 main body system, an organic solvent oil supply circulation system, an organic solvent reflux circulation system, a heating system and a sewage and steam exhaust system.

[0019] The main body system of the organic solvent tank 01 is used to store the organic solvent for cleaning the emulsifier and heat the organic solvent through a heating source; the main body system of the organic solvent tank 01 includes the organic solvent tank 01; the organic solvent tank 01 is provided with a feed port, a liquid level gauge, an on-site pressure gauge, a temperature gauge and a safety valve. The organic solvent tank 01 is configured as a jacketed pressure vessel; the organic solvent tank 01 is selected to have a volume of 1m 3 , Jacketed pressure vessel with shell material S30408; The organic solvent filter 20 main body system is used to purify and filter impurities in the organic solvent; the organic solvent filter 20 main body system includes the organic solvent filter 20. The organic solvent filter 20 is provided with a liquid level gauge, a differential pressure gauge, a field pressure gauge, a temperature gauge and a safety valve. The organic solvent filter 20 uses a shell material of S30408, a metal filter element material of 316L, and a filtration accuracy of 1 micron.

[0020] The organic solvent filtering circulation system is used to transport the high-temperature organic solvent to the organic solvent filter 20; the organic solvent filtering circulation system includes a filtering circulation pipe 10, one end of which is connected to the organic solvent tank 01 and the other end is connected to the organic solvent filter 20. The organic solvent filtering circulation system also includes a plunger pump inlet valve 11, a discharge valve 12, a plunger pump 13, a plunger pump outlet check valve 14, a stop valve 15, a pressure meter 16 and a filter inlet valve 17. The plunger pump 13 is selected to have a flow rate of 5m 3 / h, plunger pump 13 with a head of 250m.

[0021] The organic solvent circulation system is used to transport the filtered organic solvent to the emulsifier system; the organic solvent circulation system includes an oil supply circulation pipe 30, one end of which is connected to the organic solvent filter 20, and the other end is connected to the emulsifier, and a filter outlet valve 31 is provided at one end of the oil supply circulation pipe 30 close to the organic solvent filter 20. The oil supply circulation pipe 30 is provided with a pressure meter.

[0022] The organic solvent reflux circulation system is used to recycle the cleaned organic solvent into the organic solvent tank 01. The organic solvent reflux circulation system includes an organic solvent reflux pipeline 40, one end of which is connected to the emulsifier and the other end is connected to the organic solvent tank 01. An inlet electric valve 43 is provided at one end of the organic solvent reflux pipeline 40 close to the organic solvent tank 01. A pressure meter 16 is provided on the organic solvent reflux pipeline 40.

[0023] The steam heating system is used to provide a heat source for heating the organic solvent. The steam heating system includes a heating pipe 50. One end of the heating pipe 50 is connected to the heat source, and the other end is connected to the organic solvent tank 01. A solvent tank inlet stop valve 51 is provided at one end of the heating pipe 50 close to the organic solvent tank 01. The heating pipe 50 is also connected to the organic solvent filter 20 for preheating the organic solvent filter 20. A filter steam inlet electromagnetic valve 52 is provided at one end of the heating pipe 50 close to the organic solvent filter 20.

[0024] The filter circulation pipe 10, the oil supply circulation pipe 30 and the organic solvent return pipe 40 are made of 0Gr18Ni9. The heating pipe 50 is made of DN20 seamless steel pipe.

[0025] The sewage and exhaust system includes a first sewage valve 60 , a periodic sewage valve 61 , a first throttling orifice 62 , a second sewage valve 63 , an exhaust valve 64 , a second throttling orifice 65 and a third sewage valve 66 .

[0026] The first drain valve 60 is disposed below the organic solvent tank 01 and is used to control the temperature in the organic solvent tank 01 by controlling the opening of the first drain valve 60 .

[0027] The periodic sewage discharge valve 61, the first throttling orifice plate 62 and the second sewage discharge valve 63 are all arranged below the organic solvent filter 20, the periodic sewage discharge valve 61 is connected to the organic solvent filter 20, one end of the first throttling orifice plate 62 is connected to the organic solvent filter 20, and the other end is connected to the second sewage discharge valve 63.

[0028] The exhaust valve 64 , the second throttling orifice plate 65 and the third sewage valve 66 are all arranged above the organic solvent filter 20 , the exhaust valve 64 is connected to the organic solvent filter 20 , one end of the second throttling orifice plate 65 is connected to the organic solvent filter 20 , and the other end is connected to the third sewage valve 66 .

[0029] The cleaning system is configured as a skid-mounted structure, and skid-mounted reserved flange interfaces 70 are provided at the connection between the cleaning system and the heat source circulation system and at the connection between the cleaning system and the emulsifier system.

[0030] The cleaning system also includes a gateway, a signal base station, a control module and a terminal; the control module is connected to the signal base station signal through the gateway, and the terminal is connected to the base station signal. The parameters of the control module are adjusted through the terminal, and the control module is connected to the cleaning system. The cleaning system is controlled to switch in and out through the control module for cleaning.

[0031] Working principle: The cleaning equipment is connected to the original heavy oil membrane emulsification equipment and the low-pressure steam pipeline (or other heating source) through the skid-mounted reserved flange interface 70. The organic solvent tank 01 is connected to the low-pressure steam pipeline (or other heating source), the organic solvent filter 20 is connected to the feed pipeline of the original heavy oil membrane emulsification equipment, and the organic solvent tank 01 is connected to the original emulsifier outlet pipeline. The preparation work is completed.

[0032] 800~1000L of organic solvent is injected into the organic solvent tank 01 through the feeding port. The organic solvent tank 01 is connected to the low-pressure steam (or other heating source) from the production line. The solvent tank inlet stop valve 51 and the filter steam inlet solenoid valve 52 are opened. Low-pressure steam is introduced to heat the organic solvent. The organic solvent is heated to 80-180°C. When the temperature gauge on the organic solvent tank 01 shows above 150°C, the low-pressure steam (or other heating source) is closed to the filter steam inlet solenoid valve 52. The plunger pump inlet valve 11, the plunger pump outlet check valve 14 and stop valve 15, the filter inlet valve 17, the filter outlet valve 31 and the inlet electric valve 43 are opened. The plunger pump 13 is started, and the organic solvent begins to circulate. The organic solvent passes through the organic solvent filter 20 in turn through the plunger pump 13 and enters the original heavy oil membrane emulsification equipment. Then the organic solvent circulates to the organic solvent tank 01 and circulates for cleaning for 2h-3h; then, the Span 80 (surfactant, the amount of surfactant added is 0.1%~1% of the mass of the cleaning medium) is injected through the feeding port 8; the plunger pump 13 stops pumping to keep the medium immersed in the heavy oil emulsification equipment for 30min-50min. The surfactant can effectively reduce the interfacial tension of the membrane channel, so that the emulsified medium can pass through the membrane channel after the organic solvent cleaning with low resistance, effectively restoring the membrane flux; then circulate cleaning; when the transmembrane pressure difference of the heavy oil emulsification equipment is less than the preset value, the cleaning mode is cut out.

[0033] Embodiment 2: A method for cleaning a membrane emulsification device, comprising the following steps: S1. For the transmembrane pressure difference in the emulsifier, a threshold is obtained correspondingly, and a floating range of the transmembrane pressure difference is set; the floating range is set to ±30% of the threshold.

[0034] S2. Obtain the current transmembrane pressure difference in the emulsifier.

[0035] S3. Determine whether the current transmembrane pressure difference is greater than or equal to a first threshold.

[0036] S4. If the current transmembrane pressure difference is greater than or equal to the first threshold, the system operates normally and the cleaning system valve is opened.

[0037] The specific steps include: S5.1. Add an organic solvent and perform cyclic flushing for 2h-3h; the organic solvent is set to be heated and filtered diesel.

[0038] S5.2. Add surfactant, stop circulating flushing, and soak the heavy oil emulsification equipment in the medium for 30-50 minutes; the surfactant is Span 80 non-ionic surfactant, and the mass ratio of surfactant to cleaning medium is 0.1-1:1.

[0039] S5.3. Use organic solvent to perform cyclic flushing again for 10-20 minutes.

[0040] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for cleaning a membrane emulsification device, characterized in that: The following steps are involved: S1. Preset the threshold of the transmembrane pressure difference in the emulsifier and set the floating range of the transmembrane pressure difference; S2, obtaining the transmembrane pressure difference in the current emulsifier; S3, judging whether the current transmembrane pressure difference is greater than or equal to the upper limit of the threshold floating range, if the current transmembrane pressure difference is greater than or equal to the upper limit, performing the cleaning procedure of step S4; S4, supplying an organic solvent into the emulsifier for circulation, and after cleaning for a first time, adding a surfactant to the organic solvent, soaking the emulsifier, and then continuing to rinse for a second time; S5. After cleaning is completed, determine whether the transmembrane pressure difference after cleaning is within the floating range of the threshold. If the transmembrane pressure difference after cleaning is less than the upper limit of the floating range, the cleaning is completed. Otherwise, continue the cleaning procedure of step S4 until the transmembrane pressure difference is less than the upper limit of the floating range.

2. The cleaning method of membrane emulsification equipment according to claim 1, characterized in that: The first time is 2h-3h; the soaking time is 30min-50min; the second time is 10min-20min.

3. The cleaning method of membrane emulsification equipment according to claim 1, characterized in that: The surfactant is a non-ionic surfactant, and the mass ratio of the surfactant to the organic solvent is 0.1~1:

1.

4. The cleaning method of membrane emulsification equipment according to claim 1, characterized in that: Nonionic surfactants are polymers of fatty alcohols or fatty acids with ethylene oxide or acrylic acid.

5. The cleaning method of membrane emulsification equipment according to claim 1, characterized in that: The nonionic surfactant is a Tween or Span series surfactant.

6. The cleaning method of membrane emulsification equipment according to claim 1, characterized in that: After the cleaning is completed, the organic solvent is recovered and filtered and purified.

7. A cleaning system for membrane emulsification equipment, characterized in that: include: Membrane emulsification system, used for membrane emulsification treatment of heavy oil; An organic solvent tank (01), used for storing an organic solvent; An organic solvent filter (20), connected to the organic solvent tank (01), for filtering the organic solvent to remove impurities; An organic solvent supply device, used for supplying the organic solvent in the organic solvent tank (01) into the organic solvent filter (20); An organic solvent circulation tank (4) connected to the membrane emulsification system and used for storing the organic solvent during the cleaning process; The organic solvent circulation tank (4) is also connected to the organic solvent tank (01) via a valve; A porous ceramic membrane is used as an emulsifying medium in the membrane emulsification system, and a pressure measuring unit is also included in the membrane emulsification system for detecting the trans-membrane pressure difference on both sides of the porous ceramic membrane.

8. The cleaning system of the membrane emulsification equipment according to claim 7, characterized in that: The organic solvent supply device includes a plunger pump (13).

9. The cleaning system of the membrane emulsification equipment according to claim 7, characterized in that: The organic solvent filter (20) uses a metal filter element as a filter unit, and the pore size is 0.1-5 μm.

10. The cleaning system of the membrane emulsification equipment according to claim 7, characterized in that: Also includes: A steam heating system connected to the organic solvent tank (01) and / or the organic solvent filter (20) and used for heating the organic solvent tank (01) and / or the organic solvent filter (20); A sewage discharge device is provided at the bottom of the organic solvent tank (01) and the organic solvent filter (20); The organic solvent tank (01) is filled with diesel; The organic solvent tank (01) is also provided with a surfactant feeding port (8) for adding the surfactant into the organic solvent tank (01); The organic solvent tank is a jacketed pressure vessel.

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