A method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning

Abstract

The present invention belongs to the technical field of solid waste treatment and disposal, and provides a method for preparing a homogeneous catalytic ozone modified microbubble cleaning liquid and strengthening oil sludge cleaning, comprising the following steps: a surfactant solution is mixed with ozone, an ozone modified microbubble solution is prepared under high-speed stirring conditions, and a transition metal ion catalyst is added under slow stirring conditions to obtain a homogeneous catalytic ozone modified microbubble cleaning liquid. Under stirring and heating conditions, the cleaning liquid of the present invention is used for cleaning oily sludge, and the oil is eluted from the solid phase surface by reducing the interfacial tension and solubilizing the modified microbubbles, thereby reducing the residual oil rate of the oil sludge; the half-life of the homogeneous catalytic modified ozone microbubbles is controlled, and hydroxyl radicals are generated by the transition metal ion catalyst ozone, and the difficult-to-elute heavy components in the oil sludge are oxidized into easy-to-clean light components, thereby reducing the viscosity of the oil sludge, promoting the transfer of petroleum to the liquid phase, further improving the deoiling rate, and realizing efficient cleaning of the oily sludge, which has good application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste treatment and disposal, and specifically relates to a method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening oil sludge cleaning, which is suitable for oil-containing solid phase cleaning, especially for oil-containing sludge cleaning. Background Art

[0002] Oily sludge is produced in large quantities during oil drilling, storage, transportation, and refining. It is a complex and stable substance that generally contains a large amount of aged crude oil, colloids, asphaltene, suspended solids, heavy metals, radioactive elements, etc. Among them, petroleum is the most important pollutant, and its composition includes hydrocarbons and other organic mixtures. Non-hydrocarbons mainly include sulfur and nitrogen organic matter, etc. Due to the complexity of its composition, oily sludge has the characteristics of high viscosity, poor dehydration effect, difficult elution of heavy components, and high difficulty in treatment. If it is not effectively treated, it will inevitably pose a serious threat to humans and the environment.

[0003] At present, the main methods for treating oily sludge are physical and chemical technology and biological technology. Physical and chemical technology separates oil substances, suspended solids, heavy metals, etc. from oily sludge through the principles of oxidation, extraction, conditioning separation, chemical cleaning, etc., and biological technology reduces the content of oil substances and heavy metals through the principles of microbial decomposition and plant absorption. However, these methods have defects. Incineration of oil substances is not effectively utilized and toxic gases are easily produced. Chemical cleaning of oily sludge has problems such as large amount of surfactants, unsatisfactory cleaning effect, emulsification of petroleum under the action of surfactants, difficulty in recovering cleaning fluids, and difficulty in subsequent treatment.

[0004] Since oily sludge has the characteristics of high viscosity and difficulty in separating heavy components, ordinary surfactant cleaning liquid has poor cleaning effect on heavy components such as colloid and asphalt in oily sludge. A Chinese patent (application number: CN 114956495 A) discloses a pH-responsive composite surfactant cleaning liquid and a method for treating oily sludge. The method combines solvent deasphalting with chemical cleaning technology, uses n-heptane extraction pretreatment to remove heavy components in oily sludge, and then uses chemical cleaning to clean the oily sludge. This method first extracts and then chemically cleans, the extractant is expensive, and the residue in the oily sludge increases the cleaning load; two surfactants need to be added to the cleaning liquid, the amount of surfactant used is large, and the concentration can reach 5wt%, and the pH needs to be repeatedly adjusted for demulsification, which is cumbersome to operate.

[0005] In summary, in order to improve the removal efficiency of heavy oil, save energy and reduce costs, it is of great value and significance to study a simple and efficient oily sludge cleaning fluid and cleaning method. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening oil sludge cleaning, controlling the stirring intensity and time, preparing an ozone microbubble solution with high gas content, uniformity and stability under ozone conditions, adjusting the hydraulic parameters, adding a homogeneous catalyst, so that the ozone homogeneous catalyst is evenly loaded on the surface of the modified microbubbles, and obtaining a homogeneous catalytic ozone-modified microbubble cleaning liquid with both chemical cleaning and directional oxidation of oil substances. The prepared special cleaning liquid is applied to oily sludge cleaning, and the deoiling rate is improved by combining chemical cleaning with ozone directional catalytic oxidation of heavy oil. The modified ozone microbubbles are mainly composed of an ozone core and a surfactant shell coating material. The shell carries an ozone homogeneous catalyst. The modified microbubbles in the cleaning liquid solubilize and reduce the oil-water interfacial tension to promote the transfer of oil substances into the cleaning liquid. After a period of cleaning, the half-life of the ozone modified microbubbles is controlled by adjusting the ultrasonic power density, vibration amplitude and intensity. The ozone microbubbles with high mass transfer efficiency produce hydroxyl radicals under the action of the catalyst, attack the heavy oil, oxidize the difficult-to-clean heavy oil in the sludge into light components, and reduce the solid phase residual oil rate.

[0007] Technical Difficulties

[0008] (1) Petroleum is emulsified under the action of surfactants, making it difficult to recycle oil substances and increasing the difficulty of cleaning fluid processing.

[0009] (2) Chemical cleaning of oily sludge requires a large amount of surfactant, but has low cleaning efficiency for high-viscosity heavy oil components in the sludge.

[0010] (3) Ozone is easily decomposed under high pressure and high temperature conditions, and the catalytic oxidation is non-selective, making it difficult to control the directional oxidation of heavy oil by ozone.

[0011] (4) The mass transfer efficiency of ozone in water is low, the oxidation capacity is weak, and the ozone consumption of oxidized oil substances is large.

[0012] Technical Solution

[0013] The technical scheme of the method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning of the present invention is as follows:

[0014] (1) passing ozone through a surfactant solution, stirring at high speed for a period of time, and then adding a homogeneous catalyst to prepare a homogeneous catalytic ozone-modified microbubble cleaning liquid with high gas holdup, low surfactant dosage, and the functions of chemical cleaning and directional oxidation of heavy oil;

[0015] (2) Control the cleaning solid-liquid ratio, stirring intensity, cleaning time, and cleaning temperature, and apply the homogeneous catalytic ozone-modified microbubble cleaning liquid to the cleaning of oily sludge;

[0016] (3) After the cleaning liquid treats the oily sludge for a period of time, most of the light oil is removed; the cleaning reactor is placed in an ultrasonic field, the ultrasonic power density is adjusted, the horizontal vibration amplitude and intensity of the reactor are controlled, and the half-life of the homogeneous catalytic modified ozone microbubbles is controlled by vibration combined with ultrasound. Ozone produces hydroxyl radicals under the action of the catalyst, which attack the heavy oil and oxidize the difficult-to-clean heavy oil in the sludge into light components, thereby improving the oil removal rate;

[0017] (4) Add an appropriate amount of cleaning fluid to clean the heavy oil oxidation products. After cleaning, let it stand for solid-liquid separation. The tail gas ozone is treated by activated carbon adsorption, oil and water are separated, and oil substances are recovered.

[0018] The present invention provides a method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening oil sludge cleaning, which mainly comprises the following steps: mixing a sodium dodecyl sulfate and sophorolipid complex surfactant solution with a homogeneous catalyst under the condition of jet-introducing ozone, eluting the oily sludge, and deeply removing petroleum pollutants on the oil sludge by homogeneous catalysis. During the cleaning process, on the one hand, crude oil organic matter is first adsorbed on the surface of the foam due to the enhanced binding of the homogeneous catalytic ozone microbubble surface with the hydrophobic pollutants and the huge specific surface area. The surfactant carried by the homogeneous catalytic ozone modified microbubble elutes the crude oil from the solid phase surface due to adsorption and similar solubility, and the oil organic matter is transferred to the surface of the homogeneous catalytic ozone modified microbubble. Since the crude oil organic matter has a lower density than water, it will move to the upper layer in the system to achieve the purpose of crude oil removal. On the other hand, under the action of oscillation and ultrasound, the ozone modified microbubbles in the system rupture, releasing ozone to react with the homogeneous ozone catalyst adsorbed on the outer shell of the microbubble, accelerating the generation of hydroxyl free radicals, improving the ozone oxidation ability, and decomposing the difficult-to-elute heavy components in the sludge into low-molecular hydrocarbons (carboxylic acids, phenols, alcohols and gaseous organic matter) with strong hydrophilicity. Combined with the solubilization of microbubbles, reducing the oil-water interfacial tension, and wetting, most of the organic matter in the sludge is transferred to the liquid phase, further reducing the solid phase residual oil rate, and achieving efficient cleaning of oily sludge.

[0019] Therefore, the innovation of the present invention lies in that an ozone-modified microbubble cleaning liquid with high stability and both cleaning and catalytic oxidation functions is prepared at room temperature and pressure, and the modified microbubble cleaning liquid is prepared by high-speed shearing method to ensure that the ozone-modified microbubbles do not decompose during the preparation process; microbubbles are conducive to strengthening the mass transfer of ozone-liquid gas and enhancing the oxidizability of ozone; by controlling the cleaning temperature, cleaning time, hydraulic conditions and half-life of microbubbles, chemical cleaning cooperates with ozone catalytic directional oxidation of heavy oil, and the combined action strengthens the cleaning of oily sludge, improves the cleaning efficiency of heavy oil, and reduces the residual oil rate of sludge. The method of preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning in the present invention, combined with the following specific steps, is innovatively analyzed as follows:

[0020] (1) The compounding ratio of sodium dodecyl sulfate to sophorolipid is 4:6 to 6:4, and a surfactant solution is prepared with a total surfactant concentration of 0.8 to 1.2 wt % for later use.

[0021] Preferably, the biosurfactant microbiosurfactant in step (1) has good washing, dispersing emulsification, wetting and solubilizing functions, a biodegradation rate of 100%, and is environmentally friendly; sodium dodecyl sulfate and microbiosurfactant are anionic and nonionic surfactants, respectively, and the mixed adsorption layer formed after compounding reduces the electrical repulsion between the polar groups of the anions, and the adsorption of the surfactant on the interface is more dense, which can better reduce the surface tension; when the surfactant concentration is too low, the distribution density of the surfactant molecules in the shell layer is low, the outer shell of the microbubble will be thinner, easy to burst, the bubble half-life is short, and the stability is poor; when the surfactant concentration is too high, the force between the liquid films is too large, the movement of the surfactant molecules is hindered, the stability of the foam is reduced, and the half-life is shortened.

[0022] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 0.1-10 L / min, ozone is jetted into the container from the bottom, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 6000-8000 r / min for 2-2.5 minutes to produce ozone-modified microbubbles.

[0023] Preferably, in the step (2), the microbubble preparation container is isolated from air to ensure that the center of the generated microbubbles is ozone; the flow rate in the ozone generator is set to 0.1-10 L / min. If the ozone flow rate is too low, the amount of bubbles formed is small and the gas content of the solution is low. If the ozone flow rate is too high, it is not fully utilized, resulting in the decomposition of some surfactants and the destruction of the stability of the microbubbles. The stirring speed is 6000 r / min. When the speed is low, the amount of ozone stirred in is insufficient, it is not easy to foam, the foam is easy to burst, the half-life is short, and it is unstable; when the speed is too high, the gas content is in a saturated state, and increasing the speed will not increase the gas content, and the amount of foam is also not high. will increase; the optimal stirring time is 2 minutes: when stirring begins, as the stirring time increases, the bubble half-life and gas holdup gradually increase. When the stirring time is equal to 2 minutes, the microbubbles basically tend to balance. After the stirring time is greater than 2 minutes, the system temperature increases and the stability of the microbubbles weakens; the surfactant solution and ozone are sheared at a speed of 6000r / min to 8000r / min for 2 to 2.5 minutes through a serrated edge disk to produce modified microbubbles with a particle size of 10 to 100μm. The inner layer of the modified microbubbles is ozone, and the outer layer is arranged with a double layer of surfactants, and the thickness of the outer shell is one-fourth of the particle size. Considering the size of the modified microbubbles, the particle size reaches the micron level. The smaller the bubble particle size, the larger the specific surface area, the better the dispersibility, the less surfactant is used, and the oil washing effect is improved.

[0024] (3) Stop the ozone flow and add an ozone homogeneous catalyst to the microbubble solution. The homogeneous catalyst includes a transition metal ion Fe 2+ , Mn 2+ 、Ni 2+ , Cu 2+ 、Zn 2+ 、Ag + One of the above, the catalyst addition rate is 3-8 g / (L·min), ensuring that the catalyst mass concentration in the system is 0.3-0.8%.

[0025] Preferably, in step (3), if ozone is continuously introduced, the surfactant molecules on the outer shell of the microbubbles are oxidized under the action of the ion catalyst, and the stability is reduced; the optimal mass concentration of the system catalyst is 0.5%. If the mass concentration is too low, the ozone catalytic effect is not significant; if the mass concentration is too high, most of the surface of the microbubbles is occupied by transition metal ions, the solubilization and emulsification effect of the microbubble shell on oil substances is weakened, and the oil washing rate is reduced; the addition of the ion catalyst will compress the diffuse electron layer of the aggregate, weaken the repulsive effect between the "ion heads" of the surfactant, make the surfactant molecules arrange more closely, and strengthen the combination of the homogeneous modified microbubbles and the petroleum pollutants.

[0026] (4) The rotation speed is set to 60-150 r / min and the mixture is stirred slowly for 1-3 min to obtain a homogeneous catalytic ozone-modified microbubble solution.

[0027] Preferably, in step (4), the mixture is stirred slowly for 1 to 3 minutes to allow the transition metal ions to fully contact the microbubbles and be adsorbed on the surface of the microbubbles under the action of electrostatic force.

[0028] (5) Homogeneous catalytic ozone modified microbubble solution and oily sludge are added respectively according to a liquid-to-solid ratio of 10:1 to 2:1, the temperature is set at 15 to 65°C, the speed is 80 to 300 r / min, and the contact time is 5 to 30 min.

[0029] Preferably, in step (5), the liquid-to-solid ratio is too high, the cleaning agent is wasted, the liquid-to-solid ratio is too low, the amount of cleaning liquid is too small, the contact area between the oily sludge particles and the effective components on the surface of the microbubbles is small, and it is not conducive to the separation of the oil phase and the solid phase. Increasing the temperature can increase the number of collisions between the molecules of the oil substance, reduce the viscosity of the crude oil, improve the fluidity of the crude oil, increase the probability of mutual contact and collision between the surfactant molecules and the crude oil molecules in the homogeneous catalytic ozone-modified microbubbles, and accelerate the removal of the crude oil; in addition, increasing the temperature can promote the micelle aggregation of the surfactant on the homogeneous catalytic ozone-modified microbubbles, thereby increasing its ability to solubilize pollutants, and can also increase the rate of ozone generating hydroxyl radicals in subsequent operations, accelerate the oxidation rate of heavy oil, and improve the deoiling efficiency of the oily sludge. When the temperature is higher than 65°C, the oil substance is emulsified, and under high temperature conditions, the ozone is decomposed, the stability of the homogeneous catalytic ozone-modified microbubbles is weakened, resulting in a decrease in the chemical cleaning ability and the ability to oxidatively decompose heavy oil of the cleaning liquid; considering safety, economy and cleaning effect, the present invention uses 27°C as a preferred cleaning temperature. Stir at a speed of 80 to 300 r / min for 5 to 30 minutes. Slow stirring can increase the probability of solid-liquid contact and increase mass transfer efficiency. The half-life of modified microbubbles is about 50 minutes, and the decomposition time of ozone in water is 40 to 60 minutes. If the cleaning time is too long, the microbubbles will burst and the cleaning effect will deteriorate.

[0030] (6) Vibration combined with ultrasound for 1 to 3 minutes: Control the vibration amplitude of the cleaning system A = 0.1 to 10 mm, the vibration angular frequency f = 50 to 200 Hz, adjust the ultrasonic frequency to be greater than 60,000 Hz, and the ultrasonic power density to be greater than 350 W / L; add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 to 2 minutes.

[0031] Preferably, in step (6), the horizontal vibration amplitude A of the cleaning system is controlled to be 0.1 to 10 mm, the angular frequency f is controlled to be 50 to 200 Hz, the ultrasonic frequency is adjusted to be greater than 60,000 Hz, and the ultrasonic power density is adjusted to be greater than 350 W / L, so that the eddy current pulsation velocity, kinetic energy, and local shear stress are greater than or equal to the critical turbulence pulsation velocity, the modified ozone microbubbles become unstable and rupture, and under the action of a homogeneous catalyst, ozone produces hydroxyl radicals, which directionally oxidize the residual heavy oil on the sludge and decompose it into small molecular organic matter, and the oxidation process and the bubble rupture process are carried out simultaneously; after the oxidation is completed, the modified microbubble cleaning liquid is supplemented to prevent the emulsification of oil substances and to clean the decomposition products of the heavy oil.

[0032] (7) Add 0.1-0.5 wt% of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 1-10 minutes, and let stand for 5-10 minutes until the oil and water are separated, recover the oil, and recycle the cleaning liquid.

[0033] (8) The exhaust gas is collected by the gas collecting hood and ozone is absorbed by granular activated carbon.

[0034] In the step (8), the apparent density of the granular activated carbon is 0.45 to 0.6, the iodine adsorption value is >1000 mg / g, and the particle size is 200 to 1000 μm.

[0035] In the present invention, ozone-modified microbubbles reduce the critical micelle concentration of surfactants, and the amount of surfactant used is greatly reduced. The ozone-modified microbubble cleaning liquid has a solubilizing effect, and the emulsification degree of petroleum is low. A small amount of polyoxyethylene polyoxypropylene polyether can be added to break the emulsion, thereby realizing the recovery of oil substances; ozone-modified microbubbles are generated by hydraulic shearing, which ensures that ozone does not decompose and is beneficial to gas-liquid mass transfer, thereby increasing the ozone oxidation efficiency, and controlling the cleaning temperature to be lower than 65°C to ensure that ozone does not decompose before catalytic oxidation; by controlling the half-life, hydraulic parameters, cleaning temperature and cleaning time of the ozone-modified microbubbles, under the condition that the light oil on the sludge has been transferred to the liquid phase, the ozone microbubbles are broken, and a large number of hydroxyl free radicals are generated by reacting with the homogeneous catalyst, and the heavy oil remaining on the sludge is directionally oxidized, the ozone consumption is small, and the catalytic oxidation is used to improve the removal efficiency of the cleaning liquid for heavy oil.

[0036] Ozone has low oxidation activity on surfactants. Surfactants are used to wrap ozone to seal the oxidation activity of ozone. Ozone homogeneous catalysts are loaded on the surface of modified ozone microbubbles. At the moment when the microbubbles burst, ozone produces highly oxidizing hydroxyl radicals under the action of catalysts, which oxidize difficult-to-clean heavy oil into easy-to-clean carboxylic acids, phenols, and alcohols, reduce the viscosity of heavy oil, and improve the overall deoiling rate. The chemical bonds between petroleum hydrocarbons and particles are destroyed, and the stripping effect of the surfactant molecules on the modified ozone microbubble shell on petroleum organic pollutants is enhanced, thereby improving the elution rate of heavy oil. The present invention is used to remove oil substances in oily sludge, and is particularly suitable for oxidative cleaning of heavy oil in oil sludge.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] (1) The present invention provides a method for preparing homogeneous catalytic modified ozone microbubbles and their application, wherein microbubble chemical cleaning is combined with ozone oxidation to reduce the content of heavy components in oily sludge, promote the transfer of oil substances from the solid phase to the liquid phase, and improve the oil washing rate.

[0039] (2) The present invention provides a method for preparing homogeneous catalytic modified ozone microbubbles and its application. Anionic surfactants and nonionic surfactants are compounded to reduce the particle size of microbubbles to 100 μm while ensuring that ozone is not decomposed. The microbubbles have higher surface activity and surface modification effects, improve the stability of microbubbles, reduce the oil-water interfacial tension, and increase the solubility of oil in water.

[0040] (3) The present invention provides a method for preparing homogeneous catalytic modified ozone microbubbles and their application. Stirring cleaning is beneficial to increasing the contact probability between oil sludge and homogeneous catalytic modified ozone microbubbles, improving mass transfer efficiency, controlling the cleaning temperature at 27°C, reducing the ozone decomposition rate, increasing the probability of molecular collision, and improving cleaning efficiency.

[0041] (4) The rupture time of homogeneous catalytic modified ozone microbubbles is controlled by vibration combined with ultrasound, and ozone is released at the end of cleaning. Hydroxyl radicals are generated under the action of transition metal ion catalysts, which oxidize difficult-to-elute heavy oils and improve the deoiling rate of oily sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The invention relates to an inverted fluorescence microscope of the sodium dodecyl sulfate microbubbles and the sodium dodecyl sulfate sophorolipid composite bubbles.

[0043] Figure 2 It is the homogeneous catalytic ozone modified microbubble structure in the present invention.

[0044] Figure 3 The invention discloses a process for strengthening the oil sludge cleaning by using a homogeneous catalytic ozone-modified microbubble cleaning fluid. DETAILED DESCRIPTION

[0045] The present invention provides a method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning, and the specific implementation steps are as follows:

[0046] (1) The compounding ratio of sodium dodecyl sulfate to sophorolipid is 4:6 to 6:4, and a surfactant solution is prepared with a total surfactant concentration of 0.8 to 1.2% (mass concentration) for use.

[0047] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 0.1-10 L / min, ozone is jetted into the container from the bottom, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 6000-8000 r / min for 2-2.5 minutes to produce ozone-modified microbubbles.

[0048] (3) Stop the ozone flow and add a transition metal homogeneous catalyst to the microbubble solution at a catalyst addition rate of 3 to 8 g / (L·min) to ensure that the catalyst mass concentration in the system is 0.3 to 0.8%.

[0049] (4) The rotation speed is set to 60-150 r / min, and the mixture is stirred at a slow speed for 1-3 min to obtain a homogeneous catalytic ozone-modified microbubble solution for standby use.

[0050] (5) Homogeneous catalytic ozone modified microbubble solution and oily sludge are added respectively according to a liquid-to-solid ratio of 10:1 to 2:1, the temperature is set at 15 to 65°C, the speed is 80 to 300 r / min, and the stirring time is 5 to 30 min.

[0051] (6) Vibration combined with ultrasound for 1 to 3 minutes: control the vibration amplitude A = 0.1 to 10 mm, the angular frequency f = 50 to 200 Hz, adjust the ultrasonic frequency to be greater than 60,000 Hz, the ultrasonic power density to be greater than 350 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 to 2 minutes.

[0052] (7) Add 0.1-0.5 wt% of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 1-10 minutes to demulsify, let stand for 5-10 minutes, recycle the oil, and recycle the cleaning liquid.

[0053] (8) The exhaust gas is collected by the gas collecting hood, and the air flow passes through the granular activated carbon filled column to absorb ozone.

[0054] In the present invention, the particle size of the ozone-modified microbubbles is 10 μm to 100 μm, and the particle size of the ozone-modified microbubbles produced by the present method is 100 μm.

[0055] In the present invention, the total concentration of surfactants is preferably 0.8 to 1.2%, more preferably 1.0 to 1.2%.

[0056] In the present invention, the rotation speed of the high-speed stirrer is preferably 6000 r / min to 8000 r / min, and the optimal speed is 6000 r / min. The high-speed stirring time is preferably 2 to 2.5 min, and the optimal speed is 2 min.

[0057] In the present invention, the ozone flow rate is preferably 0.1 to 25 L / min, more preferably 5 to 10 L / min.

[0058] In the present invention, the ozone homogeneous catalyst comprises a transition metal ion Fe 2+ , Mn 2+ 、Ni 2+ , Cu 2+ 、Zn 2+ 、Ag + One of the following, preferably Fe 2+ The catalyst concentration in the cleaning solution is preferably 0.3-0.8%, and optimally 0.5%.

[0059] In the present invention, the pH of the catalyst solution is preferably 3-8, which can ensure that the catalytic metal ions are not hydrolyzed and precipitated.

[0060] In the present invention, the cleaning temperature is preferably 15-65°C, more preferably 20-35°C, and most preferably 27°C.

[0061] In the present invention, the cleaning time is preferably 20 to 50 minutes, more preferably 25 to 35 minutes.

[0062] In the present invention, the vibration amplitude and frequency are preferably 0.1-10 mm, 50-200 Hz, and the ultrasonic mechanical index is preferably >0.5.

[0063] In the present invention, the homogeneous catalytic ozone modified microbubble cleaning method produces ozone tail gas. After the homogeneous catalytic ozone modified microbubble cleaning, the present invention preferably also includes using granular activated carbon to absorb the exhaust gas. The granular activated carbon has an apparent density of 0.45 to 0.6, an impurity content of <0.1%, an iodine adsorption value of >1000 mg / g, and a particle size of preferably 200 to 1000 μm, more preferably 200 to 400 μm.

[0064] The present invention will be further described below in conjunction with embodiments and drawings, but the present invention is not limited by the following embodiments.

[0065] Example 1

[0066] This example is directed to a homogeneous catalytic modified ozone microbubble preparation method and its application in oil tank sludge chemical cleaning. The four components of crude oil (measured with reference to SH / T0509-92 (98)) are saturated 31.06%, aromatic 37.12%, colloid 17.12%, asphalt 14.70%, and the three components of oily sludge are water content 45.18%, solid content 43.59%, and oil content 11.23%.

[0067] (1) The compounding ratio of sodium dodecyl sulfate to sophorolipid is 6:4, and a surfactant solution is prepared with a total surfactant concentration of 1.0% (mass concentration) for use.

[0068] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 10 L / min, ozone is introduced from the bottom of the container, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 8000 r / min for 2.5 minutes to produce ozone-modified microbubbles.

[0069] (3) Stop the ozone flow and add the transition metal homogeneous catalyst Fe into the microbubble solution. 2+ , the catalyst addition rate was 8 g / (L·min) to ensure that the catalyst mass concentration in the system was 0.8%.

[0070] (4) The rotation speed is set to 150 r / min and the mixture is stirred slowly for 3 min to obtain a homogeneous catalytic modified ozone microbubble solution for standby use.

[0071] (5) Homogeneous catalytic ozone modified microbubble solution and oily sludge were added at a liquid-to-solid ratio of 10:1, and the temperatures were set at 20, 30, 40, 50, and 60 °C, respectively. The stirring time was 30 min at a speed of 300 r / min.

[0072] (6) Vibration combined with ultrasound for 3 min: control the vibration amplitude A = 10 mm, angular frequency f = 200 Hz, adjust the ultrasonic frequency to 80000 Hz, and the ultrasonic power density to 500 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 2 min.

[0073] (7) Add 0.5 wt % of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 10 min, let stand for 10 min, recycle the oil, and recycle the cleaning liquid.

[0074] (8) The exhaust gas is collected by a gas collecting hood, and the gas flow passes through a granular activated carbon column to absorb ozone. The results are shown in Table 1.

[0075] Table 1 The cleaning effect of different temperatures on oily sludge

[0076]

[0077] Example 2

[0078] This example is directed to a homogeneous catalytic modified ozone microbubble preparation method and its application in oil tank sludge chemical cleaning. The four components of crude oil (measured with reference to SH / T0509-92 (98)) are saturated 31.06%, aromatic 37.12%, colloid 17.12%, asphalt 14.70%, and the three components of oily sludge are water content 45.18%, solid content 43.59%, and oil content 11.23%.

[0079] (1) The compounding ratio of sodium dodecyl sulfate to sophorolipid is 4:6, and a surfactant solution is prepared with a total surfactant concentration of 0.8% (mass concentration) for use.

[0080] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 0.1 L / min, ozone is introduced from the bottom of the container, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 6000 r / min for 2 minutes to produce ozone-modified microbubbles.

[0081] (3) Stop the ozone flow, take 5 equal volumes of microbubble solution, and add transition metal homogeneous catalyst Fe 2+ , Mn 2+ 、Ni 2+ , Cu 2+ 、Zn 2+、Ag + , the catalyst addition rate was 3 g / (L·min) to ensure that the catalyst mass concentration in the system was 0.3%.

[0082] (4) The rotation speed is set to 60 r / min and the mixture is stirred slowly for 1 min to obtain a homogeneous catalytic modified ozone microbubble solution for standby use.

[0083] (5) Homogeneous catalytic modified ozone microbubble solution and oily sludge were added at a liquid-to-solid ratio of 2:1, the temperature was set at 15°C, the speed was 80 r / min, and the stirring time was 5 min.

[0084] (6) Vibration combined with ultrasound for 1 min: Control the vibration amplitude A = 0.1 mm, angular frequency f = 50 Hz, adjust the ultrasonic frequency to 60000 Hz, and the ultrasonic power density to 350 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 min.

[0085] (7) Add 0.1 wt% of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for min, and let stand for 5 min until the oil and water separate into layers. Recycle the oil and recycle the cleaning liquid.

[0086] (8) The exhaust gas is collected by the gas collecting hood, and the gas flow passes through the granular activated carbon filled column to absorb ozone. The results are shown in Table 2.

[0087] Table 2 Effect of different catalysts on cleaning of oily sludge

[0088]

[0089]

[0090] Example 3

[0091] This example is about a homogeneous catalytic modified ozone microbubble preparation method and its application in chemical cleaning of oil sludge in an oil field in Xinjiang. The four components of crude oil (measured with reference to SH / T0509-92 (98)) are saturated 30.12%, aromatic 37.56%, colloid 12.11%, asphalt 20.21%, and the three components of oily sludge are water content 20.11%, solid content 62.58%, and oil content 17.31%.

[0092] The processing steps are:

[0093] (1) The compounding ratio of sodium dodecyl sulfate to sophorolipid is 4:6, and a surfactant solution is prepared with a total surfactant concentration of 1% (mass concentration) for use.

[0094] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 10 L / min, ozone is introduced from the bottom of the container, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 7000 r / min to produce ozone-modified microbubbles.

[0095] (3) Stop the ozone flow and add Fe 2+ , the catalyst addition rate was 5 g / (L·min) to ensure that the catalyst mass concentration in the system was 0.8%.

[0096] (4) The rotation speed is set to 120 r / min and the mixture is stirred at a slow speed for 3 min to obtain a homogeneous catalytic modified ozone microbubble solution for standby use.

[0097] (5) Homogeneous catalytic modified ozone microbubble solution and oily sludge from an oil field in Xinjiang were added at a liquid-to-solid ratio of 5:1, the temperature was set at 27°C, the speed was 80 r / min, and the stirring time was 20 min.

[0098] (6) Vibration combined with ultrasound for 2 min: Control the vibration amplitude A = 2 mm, angular frequency f = 50 Hz, adjust the ultrasonic frequency to 70000 Hz, and the ultrasonic power density to 400 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 min.

[0099] (7) Add 0.5 wt % of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 10 min, let stand for 10 min, recycle the oil, and recycle the cleaning liquid.

[0100] (8) The exhaust gas is collected by the gas collecting hood, and the gas flow passes through the granular activated carbon filled column to absorb ozone. The results are shown in Table 3.

[0101] Table 3 Cleaning effect of different cleaning fluids on oily sludge

[0102] Cleaning fluid Residual oil rate, % Oil removal rate, % Distilled water 91.7 8.3 Sodium lauryl sulfate cleaning solution 27.6 72.4 Sophorolipid cleaning solution 17.1 82.9 Cleaning liquid of the present invention 7.9 92.1

[0103] Example 4

[0104] This example is about a homogeneous catalytic modified ozone microbubble preparation method and its application in chemical cleaning of oil sludge in an oil field. The content of the four components of crude oil (measured with reference to SH / T0509-92 (98)) is 37.11% saturated, 35.53% aromatic, 11.13% colloid, 16.22% asphalt, and the three components of oily sludge are 25.35% water content, 58.12% solid content, and 16.53% oil content.

[0105] The processing steps are:

[0106] (1) The compounding ratio of sodium dodecyl sulfate: sophorolipid is 5:5, and a surfactant solution is prepared with a total surfactant concentration of 1.2% (mass concentration) for use.

[0107] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 10 L / min, ozone is introduced from the bottom of the container, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 6000 r / min for 2.5 minutes to produce ozone-modified microbubbles.

[0108] (3) Stop the ozone flow and add the transition metal homogeneous catalyst Fe into the microbubble solution. 2+ , the catalyst addition rate was 5 g / (L·min) to ensure that the catalyst mass concentration in the system was 0.5%.

[0109] (4) The rotation speed is set to 80 r / min and the mixture is stirred slowly for 3 min to obtain a homogeneous catalytic modified ozone microbubble solution for standby use.

[0110] (5) Homogeneous catalytic modified ozone microbubble solution and oily sludge were added at a liquid-to-solid ratio of 5:1, the temperature was set at 27°C, the speed was 300 r / min, and the stirring time was 10 min.

[0111] (6) Vibration combined with ultrasound for 1 min: Control the vibration amplitude A = 2 mm, angular frequency f = 50 Hz, adjust the ultrasonic frequency to 65000 Hz, and the ultrasonic power density to 350 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 min.

[0112] (7) Add 0.3 wt % of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 5 minutes, and let stand for 8 minutes until the oil and water are separated. Recycle the oil and recycle the cleaning liquid.

[0113] (8) The exhaust gas is collected by a gas collecting hood, and the gas flow passes through a granular activated carbon column to absorb ozone. The results are shown in Table 4.

[0114] Table 4 Cleaning effect of different cleaning fluids on oily sludge

[0115]

[0116] Example 5

[0117] This example is about a homogeneous catalytic modified ozone microbubble preparation method and its application in chemical cleaning of oil sludge in an oil field. The four components of crude oil (measured with reference to SH / T0509-92 (98)) are saturated 33.78%, aromatic 32.71%, colloid 17.65%, asphalt 15.86%, and the three components of oily sludge are water content 23.16%, solid content 54.82%, and oil content 22.02%.

[0118] The processing steps are:

[0119] (1) The compounding ratio of sodium dodecyl sulfate: sophorolipid is 5:5, and a surfactant solution is prepared with a total surfactant concentration of 1.2% (mass concentration) for use.

[0120] (2) The surfactant solution is placed in a microbubble preparation container, the oxygen intake of the ozone generator is set to 10 L / min, ozone is introduced from the bottom of the container, and a high-speed stirrer with a serrated edge disk violently shears the surfactant solution and ozone bubbles at a speed of 6000 r / min for 2.5 minutes to produce ozone-modified microbubbles.

[0121] (3) Stop the ozone flow and add the transition metal homogeneous catalyst Fe into the microbubble solution. 2+ , the catalyst addition rate was 6 g / (L·min) to ensure that the catalyst mass concentration in the system was 0.6%.

[0122] (4) The rotation speed is set to 80 r / min and the mixture is stirred slowly for 3 min to obtain a homogeneous catalytic modified ozone microbubble solution for standby use.

[0123] (5) Homogeneous catalytic modified ozone microbubble solution and oily sludge were added at a liquid-to-solid ratio of 5:1, the temperature was set at 27°C, the speed was 100 r / min, and the stirring time was 25 min.

[0124] (6) Vibration combined with ultrasound for 1 min: Control the vibration amplitude A = 5 mm, the angular frequency f = 100 Hz, adjust the ultrasonic frequency to 60000 Hz, the ultrasonic power density to 350 W / L, add 10% cleaning solution, and separate the solid and liquid after cleaning for 1 min.

[0125] (7) Add 0.5 wt % of polyoxyethylene polyoxypropylene polyether as a demulsifier to the liquid separated in step (6), vibrate for 5 minutes, and let stand for 10 minutes until the oil and water are separated. Recycle the oil and recycle the cleaning liquid.

[0126] (8) The exhaust gas is collected by a gas collecting hood, and the gas flow passes through a granular activated carbon column to absorb ozone. The results are shown in Table 5.

[0127] Table 5 Cleaning effect of different cleaning fluids on oily sludge

[0128]

Claims

1. A method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning, comprising the following steps: (1) A homogeneous catalytic ozone modified microbubble cleaning liquid is prepared using a surfactant solution, ozone, and a homogeneous catalyst. During the preparation process, ozone is injected from the bottom of a container, the air intake of the ozone generator is 0.1 to 10 L / min, and the surfactant solution is stirred at a high speed to obtain a modified ozone microbubble solution; the introduction of ozone is stopped, and a homogeneous catalyst is added to the modified ozone microbubble solution, the catalyst addition rate is 3 to 8 g / (L·min), the stirring speed is controlled to be 60 to 150 r / min, and the contact time is 1 to 3 min, to obtain a homogeneous catalytic ozone modified microbubble cleaning liquid; (2) The homogeneous catalytic ozone modified microbubble cleaning liquid is stirred and mixed with the oily sludge for cleaning. The cleaning conditions are solid ratio of 10:1 to 2:1, temperature of 15 to 65°C, stirring speed of 80 to 300 r / min, and contact time of 5 to 30 min; (3) By combining vibration and ultrasound, the half-life of homogeneous catalytic modified ozone microbubbles is controlled to directionally oxidize heavy oil, and then 10% cleaning liquid is added. After cleaning for 1 to 2 minutes, the solid-liquid separation is allowed to stand, a demulsifier is added to the liquid phase, oil-water separation is performed, oil substances are recovered, and tail gas is treated.

2. The method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: In the step (1), the surfactant solution is prepared by mixing sodium dodecyl sulfate and sophorolipids in a mass ratio of 4:6 to 6:4, and the mass concentration is 0.8 to 1.2%.

3. The method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: The homogeneous catalyst in step (1) comprises a transition metal ion Fe 2+ , Mn 2+ 、Ni 2+ , Cu 2+ 、Zn 2+ 、Ag + One of the above, the mass concentration of transition metal ions is 0.3-0.8%.

4. The method for preparing a homogeneous catalytic ozone modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: In the step (1), the inner layer of the modified microbubbles is ozone, and the outer layer is arranged with a double layer of surfactant. The particle size of the microbubbles is 10 to 100 μm, and the thickness of the outer shell is one quarter of the particle size.

5. The method for preparing a homogeneous catalytic ozone-modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 4, characterized in that: In the step (1), the high-speed stirring is performed using a high-speed stirrer with a serrated edge disk, with a rotation speed of 6000 r / min to 8000 r / min and a stirring time of 2 to 2.5 min.

6. The method for preparing a homogeneous catalytic ozone modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: The method for controlling the half-life of microbubbles modified by homogeneous catalytic ozone in step (3) is characterized in that the cleaning reactor is placed in an ultrasonic field with an ultrasonic frequency greater than 60,000 Hz and a power density greater than 350 W / L, the reactor horizontal vibration amplitude A is controlled to be 0.1 to 10 mm, the vibration frequency f is controlled to be 50 to 200 Hz, and the vibration is combined with ultrasound for 1 to 3 minutes.

7. The method for preparing a homogeneous catalytic ozone modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: After the solid-liquid separation in step (3), 0.1-0.5 wt% of polyoxyethylene polyoxypropylene polyether as a demulsifier is added to the liquid, and the mixture is vibrated for 1-10 minutes. After standing for 5-10 minutes, the oil and water are separated, the oil is recycled, and the cleaning liquid is recycled.

8. The method for preparing a homogeneous catalytic ozone modified microbubble cleaning liquid and strengthening sludge cleaning according to claim 1, characterized in that: In the tail gas treatment in step (3), granular activated carbon is used to absorb ozone. The granular activated carbon has an apparent density of 0.45 to 0.6, an iodine adsorption value of >1000 mg / g, and a particle size of 200 to 1000 μm.

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