Oil sludge cleaning and separating agent, application thereof and oil sludge cleaning and separating process

Abstract

The invention relates to the technical field of oil field solid waste treatment, in particular to an oil sludge cleaning and separating agent, application thereof and an oil sludge cleaning and separating process. The oil sludge cleaning and separating agent comprises the following components in percentage by mass: 1-2% of a surfactant, 1-3% of sodium silicate, 2-6% of a builder and the balance of water, the surfactant is Tween, and the builder comprises at least one of 4A synthetic zeolite, sodium carbonate and sodium nitrilotriacetate. Through mutual cooperation of the surfactant, the sodium silicate, the builder and the water, the oil sludge cleaning and separating agent realizes separation of an oil phase, a sludge solid and a water phase in a cleaning and separating process of oil sludge, and is convenient for recycling of the oil sludge cleaning and separating agent and an oil product, so that resource consumption is reduced while oil sludge cleaning and separating are realized; therefore, the technical problem of poor oil recovery effect of the existing oily sludge treatment process is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield solid waste treatment, and particularly relates to an oily sludge cleaning and separating agent, its application and an oily sludge cleaning and separating process. Background Art

[0002] Oily sludge is an oily paste-like mixture containing oil, solid particles, soil, heavy metals and water generated during oil exploitation production and petrochemical processes. Oily sludge contains a large number of pathogenic bacteria, parasites and toxic and harmful metals such as copper, zinc, chromium and mercury.

[0003] The quantity of oily sludge is large and it is seriously harmful to the environment. Therefore, the research on the reduction, harmless treatment and resource utilization of oily sludge has attracted more and more extensive attention from researchers. At present, a series of treatment technologies for oily sludge have been developed at home and abroad, which can be roughly divided into two categories:

[0004] One category is to treat oily sludge harmlessly, such as biodegradation, oxidation treatment, solidification / stabilization, incineration, etc. The disadvantage is that resources are wasted.

[0005] The other category is the resource utilization of oily sludge. For example, solvent extraction method, centrifugal separation method, boiling water hot washing method, freezing / melting treatment method, thermal desorption method, electrolysis method and ultrasonic treatment method, etc. Due to the incomplete cleaning and stripping of oily sludge, high temperature in thermal desorption will produce cracking gas, resulting in a loss of more than 10% of the oil volume and there are major safety hazards in the explosion, which are backward processes. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art, and provide an oily sludge cleaning and separating agent, its application and an oily sludge cleaning and separating process, which solve the technical problem of poor oil recovery effect in the existing oily sludge treatment process.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions: The present invention provides an oily sludge cleaning and separating agent, which comprises the following components in mass percentage: Surfactant 1% - 2%, sodium silicate 1% - 3%, co - builder 2% - 6%, and the balance is water, totaling 100%. The surfactant is Tween, and the co - builder includes at least one of 4A synthetic zeolite, sodium carbonate and nitrilotriacetic acid trisodium salt.

[0008] Optionally, the surfactant is at least one of Tween - 21, Tween - 80 and Tween - 85.

[0009] Optionally, the sodium silicate is neutral sodium silicate or alkaline sodium silicate.

[0010] The present invention provides an application of the above-mentioned oily sludge cleaning and separating agent in an oily sludge cleaning and separating process, wherein the oil products in the oily sludge include at least one of crude oil, heavy oil, heavy diesel oil, and marine 180 fuel oil.

[0011] The present invention provides an oily sludge cleaning and separating process, comprising the following steps: Heat and stir the above-mentioned oily sludge cleaning and separating agent and the oily sludge, mix them evenly to obtain a mixture; stir the mixed liquid and the mixture to form a paste, and after standing and sedimentation treatment, under the action of gravity, the mud sand, the remaining oily sludge cleaning and separating agent, and the oil products form layers, wherein the mud sand is located at the lower layer, the oil products are located at the upper layer, and the remaining oily sludge cleaning and separating agent is located between the mud sand and the oil products.

[0012] Optionally, the mass ratio of the oily sludge cleaning and separating agent to the oily sludge is 1-3:1.

[0013] Optionally, the mass ratio of the mixed liquid to the oily sludge is 1:1, and the mixed liquid is water.

[0014] Optionally, the heating temperature for the heating and stirring is 50°C-60°C, and the stirring time is 40 min-60 min.

[0015] Optionally, the standing and sedimentation time is 40 min-120 min.

[0016] The beneficial effects of the present invention are as follows. Compared with the prior art, by selecting Tween as the surfactant to achieve the emulsification and dispersion of oil stains, using sodium silicate to adjust and control the alkaline environment in the treatment process to facilitate the saponification and decomposition of oil stains, the co-cleaning agent can play an auxiliary role and enhance the cleaning and separating effect. Water, on the one hand, serves as a dispersion medium to ensure the uniform mixing of each component, and on the other hand, can reduce the viscosity of the oily sludge through dilution to facilitate the separation of the oily sludge. In addition, the surfactant and sodium silicate can play a synergistic role. The alkaline environment formed by sodium silicate can enhance the emulsification effect of Tween, and sodium silicate itself can play a role in stabilizing the emulsification system. To sum up, through the mutual cooperation of the surfactant, sodium silicate, co-cleaning agent, and water, the oily sludge cleaning and separating agent realizes the separation of the oil phase, mud sand solids, and water phase in the process of cleaning and separating the oily sludge, facilitating the recycling of the oily sludge cleaning and separating agent and the oil products, thereby reducing resource consumption while realizing the cleaning and separation of the oily sludge, and further solving the technical problem of poor oil product recovery effect in the existing oily sludge treatment process. Description of the Drawings

[0017] Figure 1 It is a process flow diagram of an oily sludge cleaning and separating process provided by the present invention.

[0018] Figure 2 It is a physical diagram of the oily sludge in Example 6 provided by the present invention.

[0019] Figure 3 It is a physical diagram of the stratification after the oily sludge in Example 6 provided by the present invention is treated by the oily sludge cleaning and separation process. Detailed implementation manners

[0020] To solve the above technical problems, the present invention provides an oily sludge cleaning and separating agent, its application and an oily sludge cleaning and separation process. Now, the technical solutions and embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0021] The present invention will be described in detail below through specific embodiments. The embodiments are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0022] The technical solutions adopted by the present invention are as follows: The oily sludge cleaning and separating agent is divided into two specifications with contents of 5% and 10%. The oily sludge cleaning and separating agent with a content of 5% is used for normal use in oily sludge stripping production. The oily sludge cleaning and separating agent with a content of 10% is used for supplementing the loss of the oily sludge cleaning and separating agent during production. When starting up for the first time, the oily sludge cleaning and separating agent with a content of 5% is directly used, and it is used according to the weight ratio of oily sludge to the oily sludge cleaning and separating agent of 1:1 to 3.

[0023] As Figure 1 shown, the oily sludge and the oily sludge cleaning and separating agent are added to the oily sludge cleaning and separation reaction tank. At the same time, the heating system of the oily sludge cleaning and separation reaction tank is turned on, and the temperature is raised to 50°C to 60°C and continuously stirred for 1 hour.

[0024] After stirring for 1 hour, 1:1 clear water by the weight of the oily sludge is added, and stirring is continued for 0.5 hour. Then, the stirring is stopped and static settlement is carried out for 0.5 hour.

[0025] The liquid discharge port of the tank body is opened, and the stripping liquid and oil are first discharged to the oil-water separation tank; the oil sand is sent to a horizontal centrifuge to separate the residual stripping agent, and the mud and sand containing metal are first selected. After measurement, the oil content of the mud and sand is ≤2%, and it can be backfilled or used for making bricks.

[0026] Then, the oil and the stripping liquid are separated, the stripping liquid is recycled, and the oil is used for resource utilization.

[0027] Example 1 This embodiment provides an oily sludge cleaning and separating agent, which includes the following components: Tween-21, neutral sodium silicate, 4A synthetic zeolite and water.

[0028] The preparation method of the above oily sludge cleaning and separating agent includes the following steps: Dissolve Tween-21 and neutral sodium silicate in water to form a mixed solution, and then add 4A synthetic zeolite to the mixed solution and stir evenly to obtain an oily sludge cleaning and separating agent. Among them, in the oily sludge cleaning and separating agent, the mass ratio of Tween-21 is 1%, the mass ratio of neutral sodium silicate is 1.25%, the mass ratio of 4A synthetic zeolite is 2.75%, and the mass ratio of water is 95%.

[0029] Example 2 This example provides an oily sludge cleaning and separating agent, which includes the following components: Tween-85, Tween-80, neutral sodium silicate, sodium carbonate, nitrilotriacetic acid trisodium salt and water.

[0030] The preparation method of the above-mentioned oily sludge cleaning and separating agent includes the following steps: Dissolve Tween-85, Tween-80, neutral sodium silicate, sodium carbonate and nitrilotriacetic acid trisodium salt in water and stir evenly to obtain an oily sludge cleaning and separating agent. Among them, in the oily sludge cleaning and separating agent, the mass ratio of Tween-85 is 0.375%, the mass ratio of Tween-80 is 0.625%, the mass ratio of neutral sodium silicate is 1.25%, the mass ratio of sodium carbonate is 1%, the mass ratio of nitrilotriacetic acid trisodium salt is 1.75%, and the mass ratio of water is 95%.

[0031] Example 3 This example provides an oily sludge cleaning and separating agent, which includes the following components: Tween-21, neutral sodium silicate, 4A synthetic zeolite and water.

[0032] The preparation method of the above-mentioned oily sludge cleaning and separating agent includes the following steps: Dissolve Tween-21 and neutral sodium silicate in water to form a mixed solution, and then add 4A synthetic zeolite to the mixed solution and stir evenly to obtain an oily sludge cleaning and separating agent. Among them, in the oily sludge cleaning and separating agent, the mass ratio of Tween-21 is 2%, the mass ratio of neutral sodium silicate is 2.5%, the mass ratio of 4A synthetic zeolite is 5.5%, and the mass ratio of water is 90%.

[0033] Example 4 This example provides an oily sludge cleaning and separating agent, which includes the following components: Tween-85, Tween-80, neutral sodium silicate, sodium carbonate, nitrilotriacetic acid trisodium salt and water.

[0034] The preparation method of the above-mentioned oily sludge cleaning and separating agent includes the following steps: Dissolve Tween - 85, Tween - 80, neutral sodium silicate, sodium carbonate and nitrilotriacetic acid trisodium salt in water and stir evenly to prepare an oily sludge cleaning and separating agent. Among them, in the oily sludge cleaning and separating agent, the mass ratio of Tween - 85 is 0.75%, the mass ratio of Tween - 80 is 1.25%, the mass ratio of neutral sodium silicate is 2.5%, the mass ratio of sodium carbonate is 2%, the mass ratio of nitrilotriacetic acid trisodium salt is 3.5%, and the mass ratio of water is 90%.

[0035] Application Example 1 Take the dry sludge from the Daqing Oilfield, which is dry oily sludge wrapped by crude oil and yellow mud sand.

[0036] The present invention provides an oily sludge cleaning and separating process, which includes the following steps: In the oily sludge cleaning and separating reaction tank, according to the mass ratio of the oily sludge cleaning and separating agent to the oily sludge of 1.5:1, heat and stir the oily sludge cleaning and separating agent prepared in Example 1 and the dry sludge to mix evenly to obtain a mixture. Among them, the temperature of heating and stirring is 50°C, and the stirring time is 60 min.

[0037] Continue to add water with the same weight as the oily sludge, stir the water and the mixture to form a paste. After static sedimentation treatment, under the action of gravity, the mud sand, the remaining oily sludge cleaning and separating agent and the oil product form a layer. It can be observed that the bottom is gray - black oil sand, the middle layer is brown - gray emulsion layer, and the upper layer is black crude oil blocks formed on the surface of the emulsion layer. The static sedimentation time is 60 min.

[0038] Open the drain port of the oily sludge cleaning and separating reaction tank, first discharge the oily sludge cleaning and separating agent and the oil to the oil - water separation tank. The gray - black mud sand is sent to a horizontal centrifuge to separate the residual oily sludge cleaning and separating agent in the mud sand. The mud sand containing metal is selected first. After measurement, the oil content of the mud sand is ≤2%, which can be backfilled or used for making bricks.

[0039] Separate the oily sludge cleaning and separating agent and the oil in the oil - water separation tank. The oily sludge cleaning and separating agent is recycled, and the oil is used for resource utilization. The separated crude oil aggregates into oil blocks to form black crude oil blocks.

[0040] Application Example 2 Take the wet sludge fished out from the sewage pond of the Daqing Oilfield, as Figure 2 shown, which is a paste formed by mixing crude oil and carbon - powder - like colloid. Since the carbon - powder - like colloid is like black fine sand and has a large specific surface area, the separation treatment is more difficult.

[0041] The present invention provides an oily sludge cleaning and separating process, which includes the following steps: According to the ratio of the mass of the sludge cleaning and separating agent to the sludge of 1.5:1, the sludge cleaning and separating agent prepared in Example 4 and the wet sludge are heated and stirred, and mixed evenly to obtain a mixture. Among them, the temperature of heating and stirring is 60 °C, and the stirring time is 60 min.

[0042] Continue to add water with the same weight as the sludge, and stir the water and the mixture to form a paste. After static sedimentation treatment, under the action of gravity, the sand, the remaining sludge cleaning and separating agent, and the oil product form layers, as Figure 3 shown. It can be observed that the bottom is a black colloid layer, the middle layer is a brownish-gray emulsion layer, and the upper layer is black crude oil lumps formed on the surface of the emulsion layer. The static sedimentation time is 120 min.

[0043] Since a small amount of crude oil adheres to the black colloid layer deposited at the bottom, it is necessary to first pour out the brownish-gray emulsion layer and the black crude oil lumps for separation, and repeat the above-mentioned sludge separation and cleaning process for the black colloid layer again to separate the crude oil in the black colloid layer.

[0044] The above description is only the preferred embodiment of the present invention, and the above specific embodiments are not limitations on the present invention. Within the scope of the technical idea of the present invention, various deformations and modifications can occur. Any modification, modification or equivalent replacement made by those of ordinary skill in the art according to the above description belongs to the scope protected by the present invention.

Claims

1. An oily sludge cleaning and separating agent, characterized in that, Components comprising the following mass percentages: Surfactant 1% - 2%, sodium silicate 1% - 3%, builder 2% - 6%, the balance being water, totaling 100%; The surfactant is Tween, and the builder includes at least one of 4A synthetic zeolite, sodium carbonate, and nitrilotriacetic acid trisodium salt.

2. The sludge cleaning and separating agent according to claim 1, wherein The surfactant is at least one of Tween - 21, Tween - 80, and Tween - 85.

3. The sludge cleaning and separating agent according to claim 1, characterized in that, The sodium silicate is neutral sodium silicate or alkaline sodium silicate.

4. Use of the sludge cleaning and separating agent according to any one of claims 1 to 3 in a sludge cleaning and separating process, characterized in that, The oil products in the oil sludge include at least one of crude oil, heavy oil, heavy diesel oil, and marine 180 fuel oil.

5. An oil sludge cleaning and separation process, characterized in that, Comprising the following steps: Heat and stir the oil sludge cleaning and separating agent and the oil sludge according to any one of claims 1 - 3 until evenly mixed to obtain a mixture; Stir the mixed liquid and the mixture to form a paste. After static sedimentation treatment, under the action of gravity, the sand, the remaining oil sludge cleaning and separating agent, and the oil products form layers. Among them, the sand is located at the lower layer, the oil products are located at the upper layer, and the remaining oil sludge cleaning and separating agent is located between the sand and the oil products.

6. The sludge cleaning and separation process according to claim 5, characterized in that, The mass ratio of the oil sludge cleaning and separating agent to the oil sludge is 1 - 3:

1.

7. The sludge cleaning and separation process according to claim 5, characterized in that, The mass ratio of the mixed liquid to the oil sludge is 1:1, and the mixed liquid is water.

8. The sludge cleaning and separation process according to claim 5, characterized in that, The heating temperature for the heating and stirring is 50°C - 60°C, and the stirring time is 40 min - 60 min.

9. The sludge cleaning and separation process according to claim 5, characterized in that, The time for the static sedimentation is 40 min - 120 min.

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