Oil removal materials for treating residual ammonia water from coking plants, their preparation and application methods

Abstract

This invention discloses a method for preparing and using an oil-removing material for treating residual ammonia water from coking plants, belonging to the fields of water treatment technology and environmental protection. The oil-removing material is prepared by directly reacting sulfur and edible oil to produce a sulfide, coke powder, and asphalt, and then thoroughly stirring at 140-180°C for 20-40 minutes. The oil-removing material prepared by this invention has a high surface area and low specific gravity, exhibits an affinity for tar in residual ammonia water from coking plants, and demonstrates excellent oil removal performance at 60-80°C, meeting the needs of factories treating residual ammonia water from coking plants. The method of using this oil-removing material is simple, regeneration is easy, and operating costs are low; the used oil-removing material can be regenerated by placing it in a regeneration solution and can be reused repeatedly.

Description

Technical Field

[0001] This invention relates to an oil removal material for treating residual ammonia water from coking plants, and its preparation and application methods, belonging to the fields of water treatment technology and environmental protection. Background Technology

[0002] Coking wastewater refers to the organic wastewater generated during the high-temperature pyrolysis of coal to obtain coke and coal gas, as well as during the recovery of byproducts such as benzene and tar, and the purification of coal gas. Its composition is extremely complex, containing not only high concentrations of ammonia nitrogen but also large amounts of tar, phenolic compounds, sulfides, and polycyclic aromatic hydrocarbons. Coking wastewater is characterized by its pungent odor, large volume, high toxicity, and difficulty in treatment. If discharged untreated or improperly treated, it can cause significant harm to ecosystems and human health.

[0003] The main component of coking wastewater is residual ammonia water generated during high-temperature coal pyrolysis and coal gas purification. This residual ammonia water contains a high concentration of tar, which needs to be removed before entering the ammonia stripping tower. Otherwise, the tar entering the stripping tower will clog the pipes, affecting normal production and increasing the workload of workers. After ammonia stripping, the wastewater enters the biological treatment unit for further treatment. However, the tar in the wastewater significantly inhibits the activity of microorganisms, thus affecting the final wastewater treatment results. Therefore, solving the oil removal problem of the residual ammonia water before ammonia stripping is a prerequisite for ensuring that the subsequent wastewater treatment results meet standards.

[0004] Currently, methods for removing oil from residual ammonia water mainly include gravity sedimentation, pressure degreasing, gravity sedimentation filtration, and coke filtration. However, their oil removal efficiency is low, only 50% to 60%, and they involve intensive operation and high operating costs. In contrast, the widely used ceramic membrane filter technology can achieve an oil removal efficiency of around 85%, is simple to operate, and has low operating costs. However, ceramic membranes are relatively complex to manufacture, and ceramic membrane filters cannot effectively handle light oils. Their oil removal efficiency decreases as the temperature rises from 20℃ to 80℃, so the oil removal rate for residual ammonia water at temperatures generally around 80℃ is not high.

[0005] Therefore, there is a need in this field for an oil removal material that is simple to manufacture, easy to use, easy to recycle, and has a high oil removal efficiency at around 80°C, in order to solve the problems of low oil removal efficiency of residual ammonia water in coking plants, difficulty in handling light oil, and complex preparation processes and high operating costs. Summary of the Invention

[0006] This invention aims to provide an oil removal material for treating residual ammonia water from coking plants, as well as its preparation and application methods. It solves the problems of low oil removal efficiency, difficulty in treating light oil, complex preparation processes, and high operating costs in the prior art for residual ammonia water from coking plants. Effective oil removal of residual ammonia water is of great significance for stabilizing the operation of the ammonia stripping tower, improving the water quality at the biochemical inlet, and ensuring that the effluent indicators meet the standards.

[0007] This invention prepares sulfides through the direct reaction of sulfur and edible oil. The sulfur group, obtained by ring-opening at temperatures above 159°C, reacts with the olefins in the triglycerides of unsaturated edible oil to form sulfides. These sulfides exhibit excellent affinity for oils in residual ammonia water, making them a high-quality material for adsorbing oils from residual ammonia. However, their small specific surface area and poor mechanical strength limit their practical industrial application. This invention significantly improves their mechanical strength and increases their surface area by adding coke powder and asphalt. This degreasing material, using sulfur and edible oil as raw materials, has advantages such as wide availability of raw materials, low cost, simple production, high degreasing efficiency, and easy recovery. Furthermore, the sulfides synergistically enhance product performance with coke powder and asphalt, resulting in simple operation, low operating costs, and high degreasing efficiency.

[0008] This invention provides an oil removal material for treating residual ammonia water from coking plants, composed of sulfides, asphalt, and coke powder. The components and their mass fractions are as follows: sulfides: 40-60%, asphalt: 5-10%, coke powder: 35-50%. The sulfides are prepared by direct reaction of sulfur and edible oil.

[0009] The sulfur can be industrial sulfur with a sulfur content greater than 99% that conforms to GB / T 2449-2006, or sulfur-containing waste with a sulfur content greater than 90%; the oil can be one or a mixture of several oils such as soybean oil, peanut oil, rapeseed oil, or even waste cooking oil from the catering industry; the coke powder mainly comes from the screening section, environmental dust removal station, and dry quenching process dust removal station of the coking plant, with a particle size of about 3-5mm; the asphalt can be natural asphalt, coal tar pitch, petroleum asphalt, etc.

[0010] The present invention provides a method for preparing the above-mentioned degreasing material for treating residual ammonia water from coking, comprising the following steps: sulfide prepared by direct reaction of sulfur and oil, coke powder and asphalt are thoroughly mixed at 140~180℃ to obtain the material.

[0011] Specifically, it includes the following steps:

[0012] (1) Accurately weigh a certain mass (mass ratio of 5~8:2~5) of sulfur and edible oil, add sulfur to the reactor, and then heat the reactor to 180°C. When the sulfur melts and turns into an orange liquid, stir the sulfur slowly. At this time, add edible oil in proportion, mix and stir continuously at 160~180°C for 25~35 minutes. Then cool to room temperature. When the mixture becomes a viscous paste, take the mixture out of the reactor to obtain the sulfide prepared by the direct reaction of sulfur and edible oil, and grind it to 40~60 mesh.

[0013] (2) The sulfide, coke powder and pitch obtained in step (1) are reacted according to the mass percentages of sulfide (40~60%), pitch (5~10%) and coke powder (35~50%).

[0014] First, add sulfides and coke powder to the reactor, then heat the reactor to 180°C and stir continuously to mix the sulfides and coke powder evenly. At this time, add the prepared asphalt to the reactor and stir quickly to mix the three evenly. After stirring thoroughly at 140~180°C for 20~40 minutes, when the mixture becomes a viscous paste, quickly remove the mixture from the reactor into a circular mold with a diameter of 1cm. After the mixture cools, remove it from the mold to obtain the degreasing material.

[0015] This invention provides a method for using the above-mentioned degreasing material for treating residual ammonia water from coking plants. 5-10g of the degreasing material is weighed and added to a fixed-bed reactor. The residual ammonia water at 60-80°C is then introduced from bottom to top or from top to bottom at a space velocity of 2.5-10 h⁻¹. -1 The oil flows through the reactor at a certain speed. During the oil removal process, the reactor temperature is maintained at 60-80℃ through insulation or heating. The treated coking residue ammonia water collected from the fixed-bed reactor is periodically sampled and tested. When the oil removal rate is below 20%, the used oil removal material can be regenerated by placing it in the regeneration solution for 1-2 hours.

[0016] In the above regeneration process, the regeneration solution is prepared from heavy oil cleaning agent, sodium dodecylbenzene sulfonate and fatty alcohol polyoxyethylene ether, and the volume percentages of the three are as follows: heavy oil cleaning agent: 35~50%, sodium dodecylbenzene sulfonate: 30~40%, fatty alcohol polyoxyethylene ether: 15~30%.

[0017] In the above method of use, the mass-to-volume ratio of the degreasing material to the regeneration solution is 100~200 mg / mL, and the regeneration temperature is 25~30℃.

[0018] The beneficial effects of this invention are:

[0019] (1) The raw materials of the degreasing material described in this invention are widely available, inexpensive, and sustainable, which can meet the needs of large-scale industrial applications.

[0020] (2) The degreasing material prepared by the present invention has an affinity for tar in the residual ammonia water of coking, and therefore has a good degreasing efficiency.

[0021] (3) The degreasing material described in this invention is very easy to use, easy to regenerate, and has low operating costs. Attached Figure Description

[0022] Figure 1 The graphs show the COD removal rate curves of the oil removal materials in Examples 1-3.

[0023] Figure 2 The graphs show the oil removal rate curves of the oil removal materials in Examples 1-3.

[0024] Figure 3 This is a process flow diagram of the present invention. Detailed Implementation

[0025] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments. Example 1

[0026] First, accurately weigh 11.2g of national standard qualified sulfur and 4.8g of soybean oil. Add the sulfur to the reactor and then heat the reactor to 180℃. When the sulfur melts and turns into an orange liquid, stir slowly. At this time, add the edible oil, maintaining the temperature at 180℃ during the addition process. Continue stirring for 20 minutes. When the mixture becomes a viscous paste, remove the mixture from the reactor and allow it to cool to room temperature. Then, grind it into powder and pass it through a 40-mesh sieve to obtain the sulfide.

[0027] The second step involves accurately weighing 16g of the sulfide, 20g of coke powder, and 4g of pitch from the first step and adding them to the reactor. The reactor is then heated to 180°C, and the mixture is continuously stirred to ensure the sulfide and coke powder are thoroughly mixed. Next, the prepared coal tar pitch is added to the reactor, and stirring continues for 30 minutes to ensure the three are evenly mixed. When the mixture becomes a viscous paste, it is quickly discharged from the reactor into a 1cm diameter circular mold. After the mixture cools, it is removed from the mold to obtain the degreasing material.

[0028] The third step involves accurately weighing 5g of the degreasing material and adding it to the fixed-bed reactor. Residual ammonia water at 80℃ is then introduced from top to bottom at a space velocity of 5 h⁻¹. -1 The ammonia flows through the reactor at a high speed. During the oil removal process, the reactor temperature is maintained at 80℃ through insulation or heating. The treated coking waste ammonia water collected from the fixed-bed reactor is periodically sampled to test its COD removal rate and oil removal rate.

[0029] The fourth step involves testing to obtain the following results: the COD removal rate of the obtained oil removal material can reach 25-38%, and the oil removal rate can reach 65-73%.

[0030] Fifth, when the oil content in the remaining ammonia water after degreasing exceeds 50 mg / L, it is placed in a regeneration solution prepared with 40% heavy oil cleaning agent, 35% sodium dodecylbenzenesulfonate, and 25% fatty alcohol polyoxyethylene ether for 1.5 hours to regenerate the degreasing material. After repeated use 10 times, the regenerated degreasing material was tested and found that its degreasing rate remained above 63%. Example 2

[0031] First, accurately weigh 14g of coking sulfur and 6g of peanut oil. Add the sulfur to the reactor and heat the reactor to 180°C. When the sulfur melts and turns into an orange liquid, stir slowly. At this point, add the edible oil in proportion, maintaining the temperature at 180°C during the addition process. Continue stirring for 20 minutes. When the mixture becomes a viscous paste, remove the mixture from the reactor and allow it to cool to room temperature. Then, grind it into powder and pass it through a 40-mesh sieve to obtain the sulfide.

[0032] The second step involves accurately weighing 20g of the sulfide, 18g of coke powder, and 2g of petroleum asphalt from the first step and adding them to the reactor. The reactor is then heated to 180°C, and the mixture is continuously stirred to ensure the sulfide and coke powder are thoroughly mixed. Next, the prepared asphalt is added to the reactor, and stirring continues for 30 minutes to ensure the three components are evenly mixed. When the mixture becomes a viscous paste, it is quickly discharged from the reactor into a mold of a specific shape. After the mixture cools, it is removed from the mold to obtain the degreasing material.

[0033] The third step involves accurately weighing 5g of the degreasing material and adding it to the fixed-bed reactor. Residual ammonia water at 80℃ is then introduced from top to bottom at a space velocity of 5 h⁻¹. -1 The ammonia flows through the reactor at a high speed. During the oil removal process, the reactor temperature is maintained at 80℃ through insulation or heating. The treated coking waste ammonia water collected from the fixed-bed reactor is periodically sampled to test its COD removal rate and oil removal rate.

[0034] The fourth step involves testing to obtain the results: the COD removal rate of the obtained degreasing material can reach 28-40%, and its oil removal rate can reach 70-78%.

[0035] Fifth, when the degreasing material's degreasing rate is less than 20%, it is placed in a regeneration solution prepared with 40% heavy oil cleaning agent, 35% sodium dodecylbenzenesulfonate, and 25% fatty alcohol polyoxyethylene ether for 1.5 hours to regenerate the material. After repeated use 10 times, the regenerated degreasing material was tested and found that its degreasing rate remained above 70%. Example 3

[0036] First, accurately weigh 16.8g of national standard qualified sulfur and 7.2g of waste cooking oil. Add the sulfur to the reactor and then heat the reactor to 180℃. When the sulfur melts and turns into an orange liquid, stir slowly. At this time, add the cooking oil in proportion, maintaining the temperature at 180℃ during the addition process. Continue stirring for 20 minutes. When the mixture becomes a viscous paste, remove the mixture from the reactor and allow it to cool to room temperature. Then, grind it into powder and pass it through a 40-mesh sieve to obtain the sulfide.

[0037] The second step involves accurately weighing 24g of the sulfide, 14g of coke powder, and 2g of coal tar pitch from the first step and adding them to the reactor. The reactor is then heated to 180°C, and the mixture is continuously stirred to ensure the sulfide and coke powder are thoroughly mixed. Next, the prepared pitch is added to the reactor, and stirring continues for 30 minutes to ensure the three components are evenly mixed. When the mixture becomes a viscous paste, it is quickly discharged from the reactor into a mold of a specific shape. After the mixture cools, it is removed from the mold to obtain the degreasing material.

[0038] The third step involves accurately weighing 5g of the degreasing material and adding it to the fixed-bed reactor. Residual ammonia water at 80℃ is then introduced from top to bottom at a space velocity of 5 h⁻¹. -1 The ammonia flows through the reactor at a high speed. During the oil removal process, the reactor temperature is maintained at 80℃ through insulation or heating. The treated coking waste ammonia water collected from the fixed-bed reactor is periodically sampled to test its COD removal rate and oil removal rate.

[0039] The fourth step involves testing to obtain the results: the COD removal rate of the obtained degreasing material can reach 26-36%, and its oil removal rate can reach 67-75%.

[0040] Fifth, when the degreasing material's degreasing rate is less than 20%, it is placed in a regeneration solution prepared with 40% heavy oil cleaning agent, 35% sodium dodecylbenzenesulfonate, and 25% fatty alcohol polyoxyethylene ether for 1.5 hours to regenerate the degreasing material. After repeated use 10 times, the regenerated degreasing material was tested and found that its degreasing rate remained above 65%.

Claims

1. A method for using an oil-removing material for treating residual ammonia water from coking plants, characterized in that: The degreasing material is composed of sulfides, asphalt, and coke powder, and the components and their mass fractions are as follows: sulfides: 40~60%, asphalt: 5~10%, coke powder: 35~50%; the sulfides are prepared by direct reaction of sulfur and edible oil; The mass ratio of sulfur to edible oil is 5~8:2~5; The coke powder is derived from the screening section, environmental dust removal station, and dry quenching process dust removal station of the coking plant, with a particle size of 3~5mm; The sulfide is obtained by reacting the sulfur group obtained by ring opening of sulfur at above 159°C with the olefin in the triglyceride of unsaturated edible oil; by adding coke powder and asphalt, its mechanical strength and surface area can be significantly improved. The sulfide has a very good affinity with the oil in the residual ammonia water. The method of using the oil removal material for treating residual ammonia water from coking plants involves weighing 5-10g of the oil removal material and adding it to a fixed-bed reactor. The residual ammonia water at 60-80℃ is then introduced from bottom to top or from top to bottom at a space velocity of 2.5-10 h⁻¹. -1 The oil flows through the reactor at a certain speed. During the oil removal process, the temperature inside the reactor is maintained at 60~80℃ by means of heat preservation or heating. The treated coking residue ammonia water collected from the fixed bed reactor is periodically extracted for testing.

2. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 1, characterized in that: The sulfur is industrial sulfur with a sulfur content greater than 99% that conforms to the national standard GB / T 2449-2006, or sulfur-containing waste with a sulfur content greater than 90%; the edible oil is one or a mixture of soybean oil, peanut oil, and rapeseed oil; the asphalt is one of natural asphalt, coal tar pitch, and petroleum asphalt.

3. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 1, characterized in that, The preparation method of the degreasing material includes the following steps: sulfide prepared by direct reaction of sulfur and oil, coke powder and asphalt are thoroughly mixed at 140~180℃ to obtain the material.

4. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 3, characterized in that, The method for preparing the degreasing material includes the following steps: (1) Sulfur and edible oil with an accurate mass ratio of 5~8:2~5. Add sulfur to the reactor and heat the reactor to 180°C. When the sulfur melts and turns into an orange liquid, stir the sulfur slowly. At this time, add edible oil. After mixing, stir continuously at 160~180°C and react for 25~35 minutes. Then cool to room temperature. When the mixture becomes a viscous paste, take the mixture out of the reactor to obtain the sulfide prepared by the direct reaction of sulfur and edible oil. Grind it to 40~60 mesh. (2) The sulfide, coke powder and pitch obtained in step (1) are reacted according to the mass percentages of sulfide: 40~60%, pitch: 5~10%, and coke powder: 35~50%. First, add sulfides and coke powder to the reactor, then heat the reactor to 180°C and stir continuously to mix the sulfides and coke powder evenly. At this time, add the prepared asphalt to the reactor and stir quickly to mix the three evenly. After stirring thoroughly at 140~180°C for 20~40 minutes, when the mixture becomes a viscous paste, quickly remove the mixture from the reactor into a circular mold with a diameter of 1cm. After the mixture cools, remove it from the mold to obtain the degreasing material.

5. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 1, characterized in that: When the oil content in the remaining ammonia water after degreasing is higher than 50 mg / L, the used degreasing material can be regenerated by placing it in the regeneration solution for 1-2 hours.

6. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 1, characterized in that: During the regeneration process, the regeneration solution is prepared from heavy oil cleaning agent, sodium dodecylbenzene sulfonate and fatty alcohol polyoxyethylene ether, with the following volume percentages: heavy oil cleaning agent: 35~50%, sodium dodecylbenzene sulfonate: 30~40%, fatty alcohol polyoxyethylene ether: 15~30%.

7. The method of using the degreasing material for treating residual ammonia water from coking plants according to claim 1, characterized in that: The mass-to-volume ratio of the degreasing material to the regeneration solution is 100~200 mg / mL, and the regeneration temperature is 25~30℃.

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