A device and process for separating phenolic compounds from coal tar

Abstract

The application discloses a kind of coal tar phenolic compound separation device and process, polyether modified silicone oil compounding defoaming agent is added to boiler, coal tar and water, after preheating, it is mixed by first oil-water mixer, then enters second oil-water separator separation, obtains phenol-removing coal tar and water phase, water phase is sent to second oil-water separator, cooling, obtain water phase and crude phenol.The present application utilizes the solubility difference of phenolic substances and oil substances in water, thereby realizing the separation of coal tar to obtain crude phenol and phenol-removing coal tar, solving the problems of large energy consumption, complex operation process and serious environmental pollution in the extraction process of phenolic compounds in existing coal tar.The present application is a green separation process, without wastewater, waste residue and waste gas, and the process has mild and simple operating conditions, low cost and low investment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal chemical industry, and relates to a device and process for separating phenolic compounds from coal tar. BACKGROUND

[0002] Coal tar contains aliphatic hydrocarbons, aromatic hydrocarbons and phenolic compounds. According to chemical composition, it can be divided into neutral compounds, acidic compounds, oxygen-containing compounds and sulfur-containing compounds. Neutral compounds, commonly known as neutral oil, mainly include aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons are important components of fuel oil such as gasoline and diesel, and are excellent raw materials for hydrogenation to produce high-cetane diesel; aromatic hydrocarbons have high-value fine chemicals such as carbazole and quinoline that cannot be obtained or cannot be economically obtained by petroleum chemical industry. Acidic compounds mainly refer to phenolic compounds in coal tar. Phenolic compounds are important chemical raw materials and have a wide range of applications in synthetic fibers, engineering plastics, pesticides, medicines, preservatives, plasticizers, fragrances and dye intermediates, and belong to high-value fine chemical products. Based on the above, coal tar is a very valuable chemical raw material for producing high-value chemicals. It is of great significance to separate phenolic compounds from coal tar. Common separation methods for coal tar include solvent extraction, distillation and recrystallization. Generally, phenolic compounds in coal tar are separated by first distilling coal tar into fractions of different temperature ranges, and then treating the fractions by "acid-base method" to obtain crude phenol and neutral oil.

[0003] Chinese patent CN101475817A describes a distillate dephenolization process and device. Coal tar distillate is mixed with basic phenate and reacted, enters a dephenolization tower, and is allowed to stand to obtain mixed parts and neutral sodium phenate. The mixed parts are mixed with 10-12% dilute alkali and then enter a secondary dephenolization tower. The mixture is allowed to stand and separate into basic phenate and washed mixed parts. The washed mixed parts enter a dephenate tower, and after the residual basic phenate is separated in the dephenate tower, the washed mixed parts enter a basic phenate tank. The obtained washed mixed parts enter an industrial naphthalene distillation device for further processing. Although the alkali washing method can achieve the purpose of dephenolization, it will pollute the environment to some extent.

[0004] Chinese patent CN103111088A describes a complete set of equipment for separating and extracting phenolic compounds from low-temperature coal tar by extraction. The equipment is composed of five tanks, four tanks and three sets of condensers. The refined crude phenol is obtained by solvent extraction, but the equipment is complex and needs to be further improved to realize industrialization.

[0005] A method for extracting phenolic substances from coal tar using povidone is described in Chinese invention patent CN109761760A. Povidone is used as an adsorbent to mix with coal tar and stir to obtain a de-powdered coal tar phase and a povidone phase containing phenols. The povidone phase is washed with diethyl ether, and the diethyl ether washing solution is distilled under reduced pressure to obtain phenolic substances. The invention has a complicated process, and the washing, distillation, and drying processes are time-consuming, with low de-phenol efficiency, which needs to be further improved.

[0006] In summary, the current processing method of coal tar is mainly to cut different boiling point fractions by distillation, and then separate the phenolic compound components by alkali washing, acid washing, and neutralization, or to obtain relatively enriched components of coal tar by solvent extraction. There are many problems in the solvent extraction method, distillation method, and recrystallization method, such as high energy consumption in the processing of coal tar, complicated operation procedures, low separation and utilization efficiency of each component of the product, large amount of phenolic wastewater, and serious environmental pollution. SUMMARY

[0007] To overcome the problems in the prior art, the purpose of the present application is to provide a separation device and process for phenolic compounds in coal tar, which can effectively separate phenolic compounds in coal tar, and the process has high de-phenol efficiency, fewer steps, significant energy saving, mild operating conditions, no wastewater discharge, environmental friendliness, low equipment investment, and easy expansion of production scale.

[0008] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0009] A separation device for phenolic compounds in coal tar, comprising a boiler, a first oil-water mixer, a second oil-water separator, and a second oil-water separator;

[0010] The boiler outlet is connected to the inlet of the first oil-water mixer, the outlet of the first oil-water mixer is connected to the inlet of the second oil-water separator, and the outlet of the second oil-water separator is connected to the inlet of the second oil-water separator;

[0011] The stirring device comprises a stirring rod, blades arranged on the stirring rod, and a defoaming device.

[0012] Further, the defoaming device is composed of three box-shaped blades with grids.

[0013] Further, the box-shaped blades are in an arc structure, and the box-shaped blades have an inlet at one end and an outlet at the other end, with the inlet height being greater than the outlet height.

[0014] Further, the box-shaped blades are internally provided with a first metal defoaming grid and a second metal defoaming grid arranged vertically.

[0015] Further, the first oil-water mixer outlet is connected with the second oil-water mixer outlet and the second oil-water separator inlet, and a heater is arranged in the first oil-water mixer and the second oil-water mixer.

[0016] A separation process of phenolic compounds in coal tar based on the device is provided, comprising the following steps:

[0017] The polyether modified silicone oil compound defoaming agent, the coal tar and the water are added into the boiler, mixed by the first oil-water mixer after preheating, and then separated by the second oil-water separator to obtain the dephenol coal tar and the water phase.

[0018] Further, the coal tar is biomass pyrolysis oil, low / medium / high temperature coal tar, coal liquefaction oil, petroleum, biomass pyrolysis oil distillate, low / medium / high temperature coal tar distillate, coal liquefaction oil distillate or petroleum distillate.

[0019] Further, the volume ratio of the coal tar and the water is 1:0.1-1:100, the preheating temperature is 30-99℃, and the addition amount of the polyether modified silicone oil compound defoaming agent is 0.05-0.2% of the mass of the coal tar.

[0020] Further, the polyether modified silicone oil compound defoaming agent is prepared by the following method: mixing the hydrogen-containing silicone oil and the polyether according to the mass ratio of 1:10-1:30 to obtain a mixed solution, then adding 0.1%-0.3% of the mass of the mixed solution of an acid catalyst, and heating to 90-110℃ to prepare the polyether modified silicone.

[0021] The dimethyl silicone oil and the hydrophobic white carbon black are heated to 190-200℃, and then cooled to 50-60℃ after constant temperature for 3-5h to obtain a silicone paste, and then the silicone paste and the polyether modified silicone oil are compounded according to the mass ratio of 1:10-2:10 to obtain the polyether modified silicone oil compound.

[0022] The polyether modified silicone oil compound is emulsified by the Span-Tween emulsification method to obtain the polyether modified silicone oil compound defoaming agent.

[0023] Further, the specific process of emulsifying the polyether modified silicone oil compound by the Span-Tween emulsification method is as follows: mixing the Span and the Tween with different HLB values, adjusting the HLB value to 7-10 to obtain a Span-Tween emulsion; mixing the polyether modified silicone oil compound with the Span-Tween emulsion, the mass of the emulsion Span-Tween being 1%-3% of the mass of the polyether modified silicone oil compound, and stirring and emulsifying at 60-80℃.

[0024] The acid catalyst is chloroplatinic acid.

[0025] Compared with the prior art, the present application has the beneficial effects of:

[0026] The present application can heat the coal tar and water by setting the boiler; the treatment efficiency can be improved and the product quality can be improved by setting the defoaming device in the first oil-water mixer; the first oil-water mixer is set to make the preheated coal tar and water fully mixed; the fully mixed oil-water mixture enters the oil-water separator to separate the dephenolized coal tar; the water phase is sent to the oil-water separator with cooling to separate the crude phenol, and the water phase is sent to the storage tank for recycling, and the separation of the phenolic compounds in the coal tar is completed. The device has simple structure, small occupation, and is easy to expand production.

[0027] Further, the first oil-water mixer and the second oil-water mixer are provided with heaters to keep the oil-water temperature constant, so as to facilitate the full mixing of the coal tar and water.

[0028] The present application pumps the coal tar and water into the boiler for preheating, the preheated water and coal tar enter the mixer for full mixing, the fully mixed coal tar and water are pumped into the first oil-water separator, the separated dephenolized coal tar is pumped into the dephenolized coal tar storage tank, and the water phase in the first oil-water separator is pumped into the second oil-water separator to obtain the oil under water, i.e. the crude phenol, which is recycled for mixing with the coal tar. The present application utilizes the solubility difference of phenolic substances and oil substances in water to separate the crude phenol and the dephenolized coal tar from the coal tar, and solves the problems of large energy consumption, complex operation process, and serious environmental pollution in the extraction process of phenolic compounds in the existing coal tar. The present application is a green separation process, which does not produce wastewater, waste residue and waste gas, and has mild and simple operation conditions, low process and equipment cost, and low investment. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a new process flow diagram for the coal tar component separation of the present application;

[0030] Figure 2 It is a structure schematic diagram of the stirring device of the oil-water mixer of the present application;

[0031] Figure 3 It is a structure schematic diagram of the defoaming device;

[0032] Figure 4 It is a structure schematic diagram of the box-shaped blade;

[0033] Figure 5 It is a total ion flow chromatogram of the dephenolized coal tar component of Shaanbei Lantian Carbon Plant in Example 1;

[0034] Figure 6 It is a total ion flow chromatogram of the crude phenol component of Example 1;

[0035] Figure 7Total ion current chromatogram of the depitched coal tar component of AnYuan heavy oil of Example 2;

[0036] Figure 8 Total ion current chromatogram of the crude phenol component of Example 2.

[0037] In the figure, 1-boiler, 2-coal tar storage tank, 3-water storage tank, 4-depitched coal tar storage tank, 5-crude phenol storage tank, 6-first oil-water mixer, 7-second oil-water mixer, 8-second oil-water separator, 9-oil-water separator, 10-stirring device, 11-antifoaming device, 12-blade, 13-box-shaped blade. DETAILED DESCRIPTION

[0038] The application will be further described in detail below with reference to the accompanying drawings and examples.

[0039] Reference Figure 1 A device for separating phenolic compounds in coal tar comprises a boiler 1, a coal tar storage tank 2, a water storage tank 3, a depitched coal tar storage tank 4, a crude phenol storage tank 5, a first oil-water mixer 6, a second oil-water mixer 7, a second oil-water separator 8 and an oil-water separator 9. The coal tar storage tank 2 and the water storage tank 3 are both connected to the inlet of the boiler 1. The outlet of the boiler 1 is connected to the inlet of the first oil-water mixer 6. The outlet of the first oil-water mixer 6 is connected to the inlet of the second oil-water mixer 7. The outlet of the second oil-water mixer 7 is connected to the inlet of the second oil-water separator 8. The outlet of the second oil-water separator 8 is divided into two routes. One route is connected to the depitched coal tar storage tank 4. The other route is connected to the inlet of the second oil-water separator 9. The outlet of the second oil-water separator 9 is also divided into two routes. One route is connected to the crude phenol storage tank 5. The other route is connected to the water storage tank 3. The second oil-water separator 9 has a cooling function. Since the second oil-water separator 9 with the cooling function is connected to the water storage tank 3, the water in the water storage tank 3 can be used to mix with the coal tar, realizing the recycling of water. A delivery pump is arranged on each connecting pipeline of the above device. Specifically, a delivery pump is arranged between each two adjacent components of the boiler 1, the water storage tank 3, the depitched coal tar storage tank 4, the first oil-water mixer, the second oil-water mixer, the first oil-water separator and the second oil-water separator.

[0040] A heat preservation device is arranged outside the first oil-water separator 6 to ensure constant temperature.

[0041] A cooling device is arranged outside the second oil-water separator 8 to ensure that the oil-water separation is carried out under low temperature conditions.

[0042] The connecting pipelines are subjected to anti-corrosion treatment. The pipeline outside is mainly painted with anti-corrosion paint. The pipeline inside is completely and uniformly coated with epoxy glass fiber anti-corrosion material inside the pipeline to realize the anti-corrosion performance of the pipeline inside and outside, improve the service life of the conveying pipeline and reduce the cost.

[0043] Reference Figure 2, the first oil-water mixer 6 and the second oil-water mixer 7 are provided with stirring devices 10, the stirring devices 10 include stirring rods, and blades 12 are arranged on the stirring rods; and defoaming devices 11 are arranged on the stirring devices 10, the defoaming devices 11 are composed of three box-shaped blades 13 with meshes, see Figure 4 The box-shaped blade 13 is in an arc structure. The left end is a large opening end for foam entering, and the right end is a small opening end for foam outlet. Specifically, the curvature of the box-shaped blade 13 is 0.4pi, and the specific size of the box-shaped blade 13 is determined according to the size of the mixer. The diameter (outer diameter) of the box-shaped blade 13 is 1 / 3-2 / 3 of the diameter of the kettle body of the first oil-water mixer 6 and the second oil-water mixer 7, which is represented as the diameter of the stirrer dj=(1 / 3-2 / 3)Di. The height of the large opening end of the box-shaped blade 13 is 1 / 6dj, the height of the small opening end is 1 / 12dj, and the width is equal to the height. The thickness of the box-shaped blade 13 is 3mm, and the material is 316L stainless steel.

[0044] Referring to Figure 3 The box-shaped blade is provided with a first metal defoaming mesh 14 and a second metal defoaming mesh 15 made of 304 stainless steel. The first metal defoaming mesh 14 and the second metal defoaming mesh 15 are vertically arranged, and the mesh specifications are both 3mm*3mm. When the stirring device 10 rotates counterclockwise, the foam enters the large opening of the box-shaped blade 13, and after defoaming by the first metal defoaming mesh 14 and the second metal defoaming mesh 15 arranged inside, the liquid flows out of the small opening at the rear end of the box-shaped blade 13, thereby improving the processing efficiency.

[0045] When the above device is used, the coal tar and water are preheated to 30-99℃ by the boiler 1 and enter the first oil-water mixer 6. The first oil-water mixer 6 is provided with a heater for maintaining the temperature and a stirring device 10 for fully mixing. The second oil-water separator 8 is provided with a heating device to ensure that the oil-water mixture is refined and separated at 30-99℃. The second oil-water separator 9 is provided with a cooling device to ensure that the water is precipitated at 0-30℃.

[0046] The separation process of phenolic compounds in coal tar provided by the application comprises the following steps:

[0047] The polyether modified silicone oil compound defoaming agent, coal tar and water are pumped into the boiler 1 for preheating, the volume ratio of coal tar and water is 1:0.1-1:100, the addition amount of polyether modified silicone oil compound defoaming agent is 0.05-0.2% of the mass of coal tar, and the temperature is 30-99℃. The preheated coal tar and water enter the first oil-water mixer 6 for mixing, the mixed coal tar and water enter the second oil-water mixer 7 for further mixing, the further mixed coal tar and water enter the second oil-water separator 8, the obtained dephenolized coal tar is pumped to the dephenolized coal tar storage tank 4, the water phase in the second oil-water separator 8 is pumped to the second oil-water separator 9, the water phase in the second oil-water separator 9 is cooled to 0-30℃, the obtained water phase in the second oil-water separator 9 is pumped to the water storage tank 3, and the obtained crude phenol is pumped to the crude phenol storage tank 5.

[0048] The preparation method of the polyether modified silicone oil compound defoaming agent added into the boiler before the reaction starts: the hydrogen-containing silicone oil and the polyether are mixed in a mass ratio of 1:10-1:30, then 0.1%-0.3% of an acid catalyst (the acid catalyst is chloroplatinic acid) of the mass of the mixed solution is added, and preheating is performed to 90-110℃ to prepare the polyether modified silicone.

[0049] The dimethyl silicone oil and the hydrophobic white carbon black are weighed, stirred and slowly warmed, heated to 190-200℃, cooled to 50-60℃ after constant temperature for 3-5h to obtain a silicone paste, then the silicone paste is compounded with the polyether modified silicone oil in a mass ratio of 1:10-2:10 to obtain the polyether modified silicone oil compound.

[0050] The polyether modified silicone oil compound is further emulsified by the Span-Tween emulsification method, and the specific process is as follows: the Span and the Tween with different HLB values are mixed, the HLB value is adjusted to 7-10 to obtain a Span-Tween emulsion. The polyether modified silicone oil compound is mixed with the Span-Tween emulsion, the mass of the emulsion Span-Tween is 1%-3% of the mass of the polyether modified silicone oil compound, and the emulsion is stirred and emulsified at 60-80℃ to obtain the polyether modified silicone oil compound defoaming agent.

[0051] The water is desalted water; the coal tar is biomass pyrolysis oil, low-temperature / medium-temperature / high-temperature coal tar, coal liquefaction oil and petroleum and their distillate oils; all the devices and pipeline systems are pipeline systems and devices containing anticorrosion lining.

[0052] Example 1

[0053] The experimental raw material is coal tar taken from a certain Lan coal plant in Fugu County, Northern Shaanxi, and the basic properties of heavy oil (underwater oil in tar clarification tank) are measured according to the national standard (GB / T 2281-2008) and are shown in Table 1.

[0054] Table 1 Basic properties of heavy oil in a Lan coal plant in Northern Shaanxi

[0055]

[0056]

[0057] Note: * difference method

[0058] The separation process of phenolic compounds in coal tar is used to separate the crude phenol and the dephenolized coal tar from the coal tar by using clean water. In order to illustrate the effect of the present application, the separation process of phenolic compounds in coal tar is used for the separation test of the components of the medium and low temperature coal tar. In order to accurately analyze the separation products, the gas chromatography-mass spectrometry is used to determine the composition of the separation products.

[0059] The polyether modified silicone oil compound defoaming agent, 500 mL of coal tar and water are pumped into the boiler 1 for preheating, the preheating temperature of the boiler is 70 DEG C, the preheated coal tar and water enter the first oil-water mixer 6 for mixing for 2 min, the rotating speed of the stirrer in the first oil-water mixer 6 is 3000 r / min, and the mixing temperature is kept at 70 DEG C, the mixed coal tar and water enter the second oil-water mixer 7 for further mixing for 2 min, the rotating speed of the stirrer in the second oil-water mixer 7 is 3000 r / min, and the mixing temperature is kept at 70 DEG C, after mixing, the coal tar and water enter the second oil-water separator 8, the second oil-water separator 8 keeps the temperature at 70 DEG C, the dephenolized coal tar obtained by separation is pumped into the dephenolized coal tar storage tank 4 after heat exchange to 30 DEG C, the water phase in the second oil-water separator 8 is pumped into the second oil-water separator 9, the second oil-water separator 9 keeps the temperature at 20 DEG C, the water phase separated by the second oil-water separator 9 is pumped into the water storage tank 3, the crude phenol separated is pumped into the crude phenol storage tank 5, and the addition amount of the polyether modified silicone oil compound defoaming agent is 0.1% of the mass of the coal tar.

[0060] The hydrogen-containing silicone oil and the polyether are added in a mass ratio of 1:20, an acid catalyst (chloroplatinic acid) accounting for 0.2% of the total mass of the hydrogen-containing silicone oil and the polyether is added, the mixed solution is preheated to 105 DEG C, and a polyether modified silicone is prepared. The dimethyl silicone oil and the hydrophobic white carbon black are weighed, stirred and slowly heated, heated to 190 DEG C, cooled to 50 DEG C after constant temperature for 4 h, and a silicon paste is obtained, then the silicon paste and the polyether modified silicone oil are compounded in a mass ratio of 1.25:10 to obtain a polyether modified silicone oil compound. The compound is emulsified by a Span-Tween emulsification method, and Span-60 and Tween-60 are used for emulsion preparation. The polyether modified silicone oil compound and the Span-Tween emulsion are mixed, the amount of the emulsion is 2% of the mass of the polyether modified silicone oil compound, and the emulsion is stirred and emulsified at 80 DEG C to obtain a polyether modified silicone oil compound defoaming agent. The prepared compound defoaming agent is pumped into the boiler 1 to play a role in suppressing bubbles.

[0061] After the experiment, 1 mL of the dephenolated coal tar and 1 mL of the crude phenol obtained from the device were respectively dissolved in 5 mL of acetone, and then GC-MS analysis was performed, and the analysis results are shown in Table 2 and Table 3. Figure 5 , Figure 6 and Table 2 and Table 3.

[0062] Composition of neutral oil in low-temperature coal tar in Table 2

[0063]

[0064] Composition of crude phenol in low-temperature coal tar in Table 3

[0065]

[0066] From the experimental research results of Figure 5 , Figure 6 and Table 2, Table 3, it can be seen that the new separation process of phenolic compounds in coal tar adopted in the present application can effectively separate the dephenolated coal tar and the crude phenol in the coal tar.

[0067] Example 2

[0068] The experimental raw material is a low-temperature coal tar heavy oil from a certain place in northern Shaanxi, named Anyuan heavy oil, and the industrial analysis and element analysis are shown in Table 4.

[0069] Table 4 Industrial analysis and element analysis of coal tar heavy oil

[0070]

[0071] Note: * difference method

[0072] The polyether modified silicone oil compound defoaming agent and each amount of 500 mL Anyuan heavy oil and water are pumped into the boiler 1 for preheating, and the preheating temperature of the boiler is 80℃. The preheated Anyuan heavy oil and water enter the first oil-water mixer 6 for mixing for 2 minutes, the stirring speed of the first oil-water mixer 6 is 3500r / min, and the mixing temperature is kept at 80℃. The mixed Anyuan heavy oil and water enter the second oil-water mixer 7 for further mixing for 2 minutes, the stirring speed of the second oil-water mixer 7 is 3500r / min, and the mixing temperature is kept at 80℃. After mixing, the Anyuan heavy oil and water enter the second oil-water separator 8, which keeps the temperature at 80℃. The dephenolated coal tar obtained by separation is pumped to the dephenolated coal tar storage tank 4 after heat exchange to 30℃. The water phase in the second oil-water separator 8 is pumped to the second oil-water separator 9, which keeps the temperature at 20℃. The water phase obtained by separation through the second oil-water separator 9 is pumped to the water storage tank 3. The crude phenol obtained by separation is pumped to the crude phenol storage tank 5. The addition amount of the polyether modified silicone oil compound defoaming agent is 0.05% of the mass of the coal tar.

[0073] The hydrogen-containing silicone oil and the polyether are mixed in a mass ratio of 1:20, 0.2% of an acid catalyst (chloroplatinic acid) is added based on the total mass of the hydrogen-containing silicone oil and the polyether, the mixed solution is preheated to 100 DEG C, and a polyether-modified siloxane is prepared. The dimethyl silicone oil and the hydrophobic white carbon black are weighed, stirred and slowly heated to 200 DEG C, and then cooled to 60 DEG C after being kept at 200 DEG C for 5 h, to obtain a silicone paste. Then, the silicone paste is compounded with the polyether-modified siloxane in a mass ratio of 2:10, to obtain a polyether-modified siloxane compound. The compound is emulsified by a Span-Tween emulsification method, and Span-60 and Tween-20 are used for emulsion preparation. The polyether-modified siloxane compound is mixed with the Span-Tween emulsion, the amount of the emulsion is 2.5% of the mass of the polyether-modified siloxane compound, and the emulsion is stirred and emulsified at 70 DEG C, to obtain a polyether-modified siloxane compound defoaming agent. The prepared defoaming agent is pumped into the boiler 1, to play a role in inhibiting foam.

[0074] After the test is completed, 1 mL of the dephenolated coal tar and 1 mL of the crude phenol obtained from the device are respectively dissolved in 5 mL of acetone, and then GC-MS analysis is performed, and the analysis results are shown in Figure 7 、 Figure 8 and Tables 5 and 6.

[0075] Table 5: Composition of neutral oil in Anyuan heavy oil

[0076]

[0077]

[0078] Table 6: Composition of crude phenol in Anyuan heavy oil

[0079]

[0080]

[0081] From the results of Figure 7 、 Figure 8 and Tables 5 and 6, it can be seen that the phenol extraction effect of the present application is remarkable, and compared with the traditional method, the present application is a green method for separating phenolic compounds from coal tar, which does not produce waste water, waste residue and waste gas, has a small device area, low investment and easy expansion of production.

[0082] Example 3

[0083] The polyether modified silicone oil compound defoaming agent, petroleum distillate oil and water are pumped into the boiler 1 for preheating, the volume ratio of petroleum distillate oil and water is 1:0.1, the addition amount of polyether modified silicone oil compound defoaming agent is 0.2% of the mass of coal tar, and the temperature is 30°C. The preheated petroleum distillate oil and water are mixed in the first oil-water mixer 6, the mixed coal tar and water are further mixed in the second oil-water mixer 7, and the further mixed coal tar and water are separated in the second oil-water separator 8. The dephenolated coal tar obtained by separation is pumped to the dephenolated coal tar storage tank 4, and the water phase in the second oil-water separator 8 is pumped to the second oil-water separator 9. The water phase separated by the second oil-water separator 9 is pumped to the water storage tank 3, and the crude phenol obtained by separation is pumped to the crude phenol storage tank 5.

[0084] The preparation method of the polyether modified silicone oil compound defoaming agent added into the boiler before the start of the reaction is as follows: hydrogen-containing silicone oil and polyether are mixed in a mass ratio of 1:30, then 0.1% of acid catalyst (acid catalyst is chloroplatinic acid) of the mass of the mixed solution is added, and preheated to 110°C to prepare polyether modified silicone.

[0085] The dimethyl silicone oil and hydrophobic white carbon black are weighed, stirred and slowly warmed, heated to 200°C, cooled to 60°C after constant temperature for 4h, to obtain silicone paste, then the silicone paste is compounded with polyether modified silicone oil in a mass ratio of 1:10 to obtain polyether modified silicone oil compound.

[0086] The polyether modified silicone oil compound is further emulsified by Span-Tween emulsification method. The specific process is as follows: different HLB value Spans and Tweens are mixed, the HLB value is adjusted to 7 to obtain Span-Tween emulsion. The polyether modified silicone oil compound is mixed with Span-Tween emulsion, the mass of emulsion Span-Tween is 1% of the mass of polyether modified silicone oil compound, and the emulsion is stirred and emulsified at 60°C to obtain polyether modified silicone oil compound defoaming agent.

[0087] Example 4

[0088] The polyether modified silicone oil compound defoaming agent, the biomass pyrolysis oil distillate oil and water are pumped into the boiler 1 for preheating, the volume ratio of the biomass pyrolysis oil distillate oil and water is 1:100, the addition amount of the polyether modified silicone oil compound defoaming agent is 0.1% of the mass of the coal tar, and the temperature is 60 DEG C. The preheated biomass pyrolysis oil distillate oil and water are mixed in the first oil-water mixer 6, the mixed coal tar and water are further mixed in the second oil-water mixer 7, the further mixed coal tar and water are separated in the second oil-water separator 8, the obtained dephenolized coal tar is pumped to the dephenolized coal tar storage tank 4, the water phase in the second oil-water separator 8 is pumped to the second oil-water separator 9, the water phase separated by the second oil-water separator 9 is pumped to the water storage tank 3, and the obtained crude phenol is pumped to the crude phenol storage tank 5.

[0089] The preparation method of the polyether modified silicone oil compound defoaming agent added into the boiler before the reaction starts: the hydrogen-containing silicone oil and the polyether are mixed in a mass ratio of 1:10, then 0.3% of the acid catalyst (the acid catalyst is chloroplatinic acid) of the mass of the mixed solution is added, and preheated to 90 DEG C to prepare the polyether modified silicone.

[0090] The dimethyl silicone oil and the hydrophobic white carbon black are weighed, stirred and slowly warmed, heated to 1950 DEG C, cooled to 55 DEG C after constant temperature for 4h, and then the silicon paste is obtained. Then the silicon paste and the polyether modified silicone oil are compounded in a mass ratio of 2:10 to obtain the polyether modified silicone oil compound.

[0091] The polyether modified silicone oil compound is further emulsified by the Span-Tween emulsification method. The specific process is as follows: the Span and the Tween with different HLB values are mixed, the HLB value is adjusted to 10 to obtain the Span-Tween emulsion. The polyether modified silicone oil compound is mixed with the Span-Tween emulsion, the mass of the emulsion Span-Tween is 3% of the mass of the polyether modified silicone oil compound, the stirring emulsion is heated to 70 DEG C to obtain the polyether modified silicone oil compound defoaming agent.

[0092] Example 5

[0093] The polyether modified silicone oil compound defoaming agent, high temperature coal tar and water are pumped into the boiler 1 for preheating. The volume ratio of high temperature coal tar and water is 1:10, the addition amount of polyether modified silicone oil compound defoaming agent is 15% of the mass of coal tar, and the temperature is 99℃. The preheated high temperature coal tar and water enter the first oil-water mixer 6 for mixing. The mixed coal tar and water enter the second oil-water mixer 7 for further mixing. After further mixing, the coal tar and water enter the second oil-water separator 8. The dephenolated coal tar obtained by separation is pumped to the dephenolated coal tar storage tank 4. The water phase in the second oil-water separator 8 is pumped to the second oil-water separator 9. The second oil-water separator 9 cools the water phase to 10℃. The water phase obtained by separation through the second oil-water separator 9 is pumped to the water storage tank 3. The crude phenol obtained by separation is pumped to the crude phenol storage tank 5.

[0094] The preparation method of the polyether modified silicone oil compound defoaming agent added into the boiler before the start of the reaction is as follows: hydrogen-containing silicone oil and polyether are mixed in a mass ratio of 1:20, then 0.2% of acid catalyst (acid catalyst is chloroplatinic acid) of the mass of the mixed solution is added, and preheated to 100℃ to prepare polyether modified siloxane.

[0095] The dimethyl silicone oil and hydrophobic white carbon black are weighed, stirred and slowly warmed, heated to 190℃, and then cooled to 60℃ after constant temperature for 5h to obtain silicone paste. Then the silicone paste is compounded with polyether modified silicone oil in a mass ratio of 1.5:10 to obtain polyether modified silicone oil compound.

[0096] The polyether modified silicone oil compound is further emulsified by Span-Tween emulsification method. The specific process is as follows: different HLB value Spans and Tweens are mixed, and the HLB value is adjusted to 8 to obtain Span-Tween emulsion. The polyether modified silicone oil compound is mixed with Span-Tween emulsion, the mass of emulsion Span-Tween is 2% of the mass of polyether modified silicone oil compound, and the emulsion is stirred and emulsified at 80℃ to obtain polyether modified silicone oil compound defoaming agent.

[0097] Example 6

[0098] The polyether modified silicone oil compound defoaming agent, the biomass pyrolysis oil and water are preheated into the boiler 1, the volume ratio of the biomass pyrolysis oil and water is 1:60, the polyether modified silicone oil compound defoaming agent is added in the amount of 0.05% of the mass of the coal tar, and the temperature is 45 DEG C; the preheated biomass pyrolysis oil and water enter the first oil-water mixer 6 for mixing; the mixed coal tar and water enter the second oil-water mixer 7 for further mixing; the further mixed coal tar and water enter the second oil-water separator 8; the dephenolized coal tar obtained by separation is pumped into the dephenolized coal tar storage tank 4; the water phase in the second oil-water separator 8 is pumped into the second oil-water separator 9; the water phase separated by the second oil-water separator 9 is pumped into the water storage tank 3; and the crude phenol obtained by separation is pumped into the crude phenol storage tank 5.

[0099] The preparation method of the polyether modified silicone oil compound defoaming agent added into the boiler before the reaction starts is as follows: the hydrogen-containing silicone oil is mixed with the polyether at a mass ratio of 1:15, then 0.1% of the acid catalyst (the acid catalyst is chloroplatinic acid) of the mass of the mixed solution is added, and preheating is carried out to 95 DEG C to prepare the polyether modified silicone.

[0100] The dimethyl silicone oil and the hydrophobic white carbon black are weighed, stirred and slowly heated to 200 DEG C, and then cooled to 50 DEG C after constant temperature for 3h to obtain a silicone paste; then the silicone paste is compounded with the polyether modified silicone oil at a mass ratio of 2:10 to obtain the polyether modified silicone oil compound.

[0101] The polyether modified silicone oil compound is further emulsified by the Span-Tween emulsification method, and the specific process is as follows: the Span and the Tween with different HLB values are mixed, and the HLB value is adjusted to 9 to obtain a Span-Tween emulsion; the polyether modified silicone oil compound is mixed with the Span-Tween emulsion, the mass of the emulsion Span-Tween is 1.5% of the mass of the polyether modified silicone oil compound, and the emulsion is obtained by stirring and emulsifying at 65 DEG C to obtain the polyether modified silicone oil compound defoaming agent.

[0102] The present application can realize the separation of the crude phenol and the dephenolized coal tar from the coal tar, and solve the problems of large energy consumption, complex operation process and serious environmental pollution in the extraction process of the phenolic compounds in the existing coal tar. The present application is a green separation process, which does not produce waste water, waste residue and waste gas, and the operation conditions are mild and simple, the process and equipment cost are low, and the investment is small.

Claims

1. A device for separating phenolic compounds in coal tar, characterized by, The device comprises a boiler (1), a first oil-water mixer (6), a first oil-water separator (8) and a second oil-water separator (9); The outlet of the boiler (1) is connected with the inlet of the first oil-water mixer (6), the outlet of the first oil-water mixer (6) is connected with the inlet of the first oil-water separator (8), and the outlet of the first oil-water separator (8) is connected with the inlet of the second oil-water separator (9); the first oil-water separator (8) is provided with a heating device, and the second oil-water separator (9) is provided with a cooling device; The outlet of the first oil-water mixer (6) is connected with the inlet of the first oil-water separator (8) through the second oil-water mixer (7), and the first oil-water mixer (6) and the second oil-water mixer (7) are provided with a heater; the first oil-water mixer (6) and the second oil-water mixer (7) are provided with a stirring device (10), which comprises a stirring rod and blades (12) and a defoaming device (11) arranged on the stirring rod; The defoaming device (11) is composed of three box-shaped blades (13) with grids; The box-shaped blade (13) has an arc structure, one end of the box-shaped blade (13) is provided with an inlet, and the other end is provided with an outlet; the height of the inlet is greater than that of the outlet; the inlet is a large end for foam entering, and the outlet is a small end for foam outlet; the curvature of the box-shaped blade (13) is 0.4π; The box-shaped blade (13) is provided with a first metal defoaming grid (14) and a second metal defoaming grid (15) arranged vertically inside the box-shaped blade (13).

2. A process for the separation of phenolic compounds from coal tar based on the apparatus of claim 1, characterized in that, The device comprises the following steps: Polyether modified silicone oil compound defoamer, coal tar and water are added into the boiler (1), preheated, mixed through the first oil-water mixer (6), then separated into the first oil-water separator (8) to obtain dephenol coal tar and water phase, and the water phase is sent to the second oil-water separator (9) to cool to obtain water phase and crude phenol.

3. The process for separating phenolic compounds from coal tar according to claim 2, characterized in that, The coal tar is biomass pyrolysis oil, low / medium / high temperature coal tar, coal liquefaction oil, petroleum, biomass pyrolysis oil distillate, low / medium / high temperature coal tar distillate, coal liquefaction oil distillate or petroleum distillate.

4. The process for separating phenolic compounds from coal tar according to claim 2, wherein, The volume ratio of coal tar to water is 1:0.1-1:100; the preheating temperature is 30-99℃; the addition amount of polyether modified silicone oil compound defoamer is 0.05-0.2% of the mass of coal tar.

5. The process for separation of phenolic compounds from coal tar according to claim 2, wherein, The polyether modified silicone oil compound defoamer is prepared by the following method: hydrogen-containing silicone oil and polyether are mixed in a mass ratio of 1:10-1:30 to obtain a mixed solution, then 0.1%-0.3% of an acid catalyst is added to the mixed solution, heated to 90-110℃, and polyether modified silicone is prepared; Dimethyl silicone oil and hydrophobic white carbon black are heated to 190-200℃, kept at constant temperature for 3-5h, then cooled to 50-60℃ to obtain silicone paste, then the silicone paste is compounded with polyether modified silicone oil in a mass ratio of 1:10-2:10 to obtain polyether modified silicone oil compound; The polyether modified silicone oil compound is emulsified by Span-Tween emulsification method to obtain polyether modified silicone oil compound defoamer.

6. The process for separating phenolic compounds from coal tar according to claim 5, wherein, The specific process of emulsifying the polyether-modified silicone oil compound by the Span-Tween emulsification method is as follows: mixing Spans with different HLB values and Tween to adjust the HLB value to 7-10 to obtain a Span-Tween emulsion; mixing the polyether-modified silicone oil compound with the Span-Tween emulsion, the mass of the Span-Tween emulsion being 1%-3% of the mass of the polyether-modified silicone oil compound, and stirring and emulsifying at 60-80 ℃; The acid catalyst is chloroplatinic acid.

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