Purification method of coal derived oil and application of purified coal derived oil

Abstract

The invention discloses a purification method of coal derived oil and application of purified coal derived oil, and relates to the technical field of coal chemical industry. The method comprises the following steps: heating the coal derived oil until the coal derived oil reaches a first preset temperature; adding a purifying agent into the heated coal derived oil, and mixing the purifying agent with the coal derived oil to separate out oil-soluble metals in the coal derived oil; then carrying out separation treatment on the obtained coal derived oil intermediate material, and separating water, naphtha fraction, carbolic oil fraction and coal derived oil bottom oil; and finally, carrying out phenol extraction treatment on the carbolic oil fraction to obtain crude phenol and dephenolized oil, mixing the naphtha fraction, the dephenolized oil and bottom oil of the coal derived oil, and carrying out solid-liquid separation treatment to obtain purified oil of the coal derived oil. The purification method provided by the invention can realize demetallization, dehydration and solid removal of the coal derived oil, effectively reduces the oxygen content in the coal derived oil, and improves the purification rate and yield of the coal derived oil.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical industry, and in particular to a method for purifying coal-derived oil. Background Art

[0002] Coal-derived oil refers to the full fraction or distillate oil produced by a series of coal chemical process with coal as the source, such as coal gasification, coal tar as a by-product of dry distillation and pyrolysis, and coal direct liquefaction oil. The use of fixed-bed hydrogenation technology is one of the most effective means to process coal-derived oil into light oil products and chemicals.

[0003] Coal-derived oil is a low-quality heavy raw material with high content of impurities such as water, metals, active oxygen-containing compounds and solid particles. These impurities can have a serious impact on the stable operation of the hydrogenation unit, catalyst activity and product quality.

[0004] Water in coal-derived oil can cause fluctuations in the operating temperature of the heating furnace and increase energy consumption. Water vapor can cause serious catalyst pulverization and reduce hydrogenation activity. The metals in coal-derived oil are mainly Fe, Ca, Al, Na, Mg, K and other elements. During the hydrogenation reaction, most of these metals are removed in the pretreatment reactor in the form of sulfides and deposited in the pretreatment catalyst pores and between catalyst particles, causing the catalyst pores to be blocked and the active centers to be covered, and the pressure drop of the catalyst bed to increase, affecting the long-term operation of the device. The solid particles in coal-derived oil are mainly coal powder, coke powder and mechanical impurities. These solid particles can cause serious blockage of hydrogenation equipment, pipelines and catalyst beds. One of the characteristics of coal-derived oil is its high oxygen content, accounting for about 5% to 8%, of which phenols are the main ones, accounting for about 20% to 30%. The low-grade phenol is a valuable basic chemical raw material, and it is also an intermediate for products such as medicines, pesticides, spices, pigments, antioxidants, etc. It has extremely high economic value. The extraction and separation of phenols is one of the important means to increase the value of coal-derived oil. At the same time, the hydrogenation reaction of these active oxygen-containing compounds in coal-derived oil is a highly exothermic reaction, which can easily cause the reactor to overheat during the reaction. The water generated by the reaction can also easily cause the catalyst to pulverize and deactivate.

[0005] Coal-derived oil hydrogenation projects mainly use vacuum distillation or delayed coking technology to cut off 15% to 25% of asphalt or coke to reduce the content of metals and solid particles in the raw materials. This method has low raw material utilization, and when processing coal tar with high metal content (>400mg / L), even if the asphalt component is cut off, the metal content in the distillate oil often exceeds 20μg / g, greatly shortening the operation cycle of the device. Compared with the cut fraction hydrogenation, the full-fraction coal-derived oil hydrogenation technology has the advantages of high resource utilization and technical and economic feasibility. It is the preferred process to reduce resource waste, environmental pollution and improve resource utilization. The key to achieving full-fraction hydrogenation lies in the coal-derived oil purification pretreatment technology.

[0006] At present, the commonly used methods for purifying coal-derived oil mainly include sedimentation separation, centrifugal separation, electric field purification (electric desalting and dehydrating device), chemical separation, solvent extraction, cyclone separation, filtration separation and other separation methods. Among them, CN100999675A discloses an electric field purification method for coal tar, and CN102079983A discloses a coal tar pretreatment process and complete set of equipment. Both of them use electric field purification (electric desalting and dehydrating device) to remove impurities in coal tar, that is, inject a certain amount of fresh water into the coal tar, and after sufficient mixing, under the action of demulsifier and high-voltage electric field, tiny water droplets are aggregated into larger water droplets, and then the density difference is used to separate oil and water to achieve the purpose of desalting and dehydrating. This method produces a large amount of coal chemical wastewater, and due to the emulsification problem, it is difficult to purify and cannot achieve impurity removal well. CN106398735A discloses a coal tar pretreatment method, which injects water, salt and demulsifier into the coal tar, separates the oil and water after mixing, separates the coal tar into above-water oil and below-water oil, filters them separately to remove solid impurities, and finally pickles and washes the below-water oil. The method has a complex process flow, uses a filtering device with a pore size of 0.1 to 1.0 μm, has high precision, and has a large investment cost.

[0007] The purification methods in the above-mentioned prior art all have defects such as poor separation effect and low efficiency, and do not take into account the properties of coal-derived oil such as high oxygen content and high phenol content. There are problems such as practical operation difficulties and unsatisfactory purification effects, and they cannot meet the quality requirements of subsequent hydrogenation units and catalysts for coal-derived oil. Summary of the invention

[0008] One of the purposes of the present invention is to provide a method for purifying coal-derived oil, which can achieve demetallization, dehydration and desolidification of coal-derived oil, effectively reduce the oxygen content in the coal-derived oil, and improve the purification rate and yield of the coal-derived oil.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A method for purifying coal-derived oil comprises the following steps in sequence:

[0011] (1) heating the coal-derived oil to a first preset temperature, wherein the first preset temperature is 60 to 200° C.;

[0012] (2) adding a purifier to the coal-derived oil heated in step (1), wherein the purifier is used to separate the oil-soluble metals in the coal-derived oil;

[0013] The amount of the purifier added is 0.01 to 1% by weight of the coal-derived oil;

[0014] The purifying agent is carboxylic acid, phosphoric acid, carboxylate, phosphate, decalcifying agent or deironifying agent;

[0015] (3) separating the coal-derived oil intermediate material obtained in step (2) to separate water, naphtha fraction, phenol oil fraction and coal-derived oil bottom oil;

[0016] (4) subjecting the phenol oil fraction to phenol extraction to obtain crude phenol and dephenolized oil, and mixing the naphtha fraction, the dephenolized oil and the coal-derived oil bottom oil to solid-liquid separation to obtain coal-derived oil purified oil.

[0017] In the above-mentioned method for purifying coal-derived oil, in step (1), the first preset temperature is 80-120°C.

[0018] In the above-mentioned method for purifying coal-derived oil, in step (2), the amount of the purifier added is 0.05-0.5% of the weight of the coal-derived oil; the purifier reacts with the oil-soluble metals in the coal-derived oil at the oil-water interface, and causes the metal ions to ionize or form precipitates or chelates, thereby separating the oil-soluble metals; the purifier is a carboxylate, a phosphate, a decalcifying agent or a deironifying agent.

[0019] In the above-mentioned method for purifying coal-derived oil, the carboxylate is sodium carboxylate or potassium carboxylate; and the phosphate is orthophosphate or metaphosphate.

[0020] In the above-mentioned method for purifying coal-derived oil, the commercially available brand of the purifier is YX-F-101, KJ-FMT3 or KJ-FMT3.

[0021] In the above-mentioned method for purifying coal-derived oil, in step (3), the steps of separating and treating the coal-derived oil intermediate material are as follows: heating the coal-derived oil intermediate material to evaporate the water in the coal-derived oil intermediate material; continuing to heat the coal-derived oil intermediate material to evaporate the naphtha fraction and the phenol oil fraction in the coal-derived oil intermediate material, and the oil at the bottom is the coal-derived oil bottom oil.

[0022] In the above-mentioned method for purifying coal-derived oil, in step (4), the phenol extraction treatment is carried out by using solvent extraction, alkali extraction or Na2CO3 solution elution method.

[0023] In the above-mentioned method for purifying coal-derived oil, the solvent selected for solvent extraction of phenol is methanol, ethylene glycol, glycerol, sodium phenolate, sodium xylene sulfonate or acidic sodium sulfite.

[0024] In the above-mentioned method for purifying coal-derived oil, in step (2), the mixing time of the coal-derived oil and the purifier is 10 to 60 minutes; and in step (3), the separation treatment temperature is set to 170 to 250°C.

[0025] Another object of the present invention is to provide the use of the coal-derived oil purified oil obtained by the above purification method in coal-derived oil hydrogenation experiments.

[0026] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0027] (1) The method for purifying coal-derived oil proposed by the present invention comprises the following steps: firstly, heating the coal-derived oil, then adding a purifying agent thereto, performing a separation treatment by heating, performing a phenol extraction treatment on the phenol oil fraction obtained by separation to obtain crude phenol and dephenolized oil, and then mixing the dephenolized oil obtained by the phenol extraction treatment with the naphtha fraction obtained by separation and the coal-derived oil bottom oil, and then performing a solid-liquid separation treatment to obtain coal-derived oil purified oil. The present invention has simple operation steps, does not require water injection, does not generate additional wastewater, and is environmentally friendly.

[0028] (2) The coal-derived oil purified oil obtained by the present invention can significantly reduce the content of active oxygen-containing compounds of phenols in the fixed bed feedstock, effectively control the reactor temperature runaway and coking caused by the strong exothermic reaction of hydrodeoxygenation, and significantly reduce the effects of catalyst pulverization and deactivation caused by water generated during hydrodeoxygenation.

[0029] (3) The method of the present invention can extract phenolic compounds with high economic value, and further realize the high-value utilization of medium- and low-temperature coal-derived oil.

[0030] (4) The present invention provides purified coal-derived oil that can achieve fixed-bed full-fraction hydrogenation. Compared with cut fraction hydrogenation, full-fraction coal-derived oil hydrogenation technology has the advantages of high resource utilization and technical and economic feasibility. It is an effective means to reduce resource waste, environmental pollution and improve enterprise benefits.

[0031] (5) The present invention adds a small amount of purifier to the coal-derived oil containing a large amount of impurities, so that the oil-soluble metals in the coal-derived oil and the purifier react in contact at the oil-water interface, so that the metal ions are ionized or form precipitates or chelates, and then solid-liquid separation equipment is used for effective separation. The separation is fast and effective. The coal-derived oil purification rate reaches 93-97%, and the yield of the purified coal-derived oil reaches 95-97%.

[0032] (6) The solid slag produced by the solid-liquid separation of the present invention can be used as fuel and burned together with coal, which greatly reduces the generation of solid waste and is environmentally friendly. DETAILED DESCRIPTION

[0033] The present invention proposes a method for purifying coal-derived oil and an application of purified coal-derived oil. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is further described below in conjunction with specific embodiments.

[0034] The raw materials described in the present invention can be purchased through commercial channels.

[0035] The purifier described in the present invention is carboxylic acid, phosphoric acid, carboxylate, phosphate, decalcifying agent or deferrifying agent; wherein carboxylate is such as sodium carboxylate, potassium carboxylate, etc., phosphate is such as trisodium phosphate, calcium phosphate, etc.; the commercially available brand of decalcifying agent or deferrifying agent used is YX-F-101, KJ-FMT3 or KJ-FMT3.

[0036] The solvent selected for solvent extraction of phenol in the present invention is methanol, ethylene glycol, glycerol, sodium phenolate, sodium xylene sulfonate or acidic sodium sulfite.

[0037] A method for purifying coal-derived oil comprises the following steps in sequence:

[0038] (1) heating the coal-derived oil to a first preset temperature, wherein the first preset temperature is 60 to 200° C.; heating the coal-derived oil raw material to the first preset temperature, adding a purifier to the heated coal-derived oil raw material and mixing them to form a coal-derived oil intermediate material. Specifically, by heating the coal-derived oil raw material, the mixing effect of the purifier and the coal-derived oil raw material can be effectively improved, thereby improving the purification effect of the purifier.

[0039] (2) Adding a purifier to the heated coal-derived oil, wherein the amount of the purifier added is 0.01-1% by weight of the coal-derived oil, preferably 0.05-0.5% by weight; the purifier is carboxylic acid, phosphoric acid, carboxylate, phosphate, decalcifying agent or deironifying agent.

[0040] A purifier is added to the coal-derived oil raw material containing a large amount of impurities, so that the oil-soluble metals in the coal-derived oil raw material can contact and react with the purifier at the oil-water interface, so that the metal ions are ionized or form precipitates or chelates, and then the oil-soluble metals are separated. Crude phenol can be obtained through phenol extraction treatment, and the extracted crude phenol can further improve the economic benefits of coal-derived oil processing.

[0041] More preferably, the weight of the purifier is limited to 0.05-0.5% of the weight of the coal-derived oil raw material, thereby further improving the utilization rate of the purifier and avoiding the problem of incomplete purification due to too low a content of the purifier, for example, when the weight of the purifier accounts for less than 0.05% of the weight of the coal-derived oil raw material, the oil-soluble metals in the coal-derived oil raw material may not be completely precipitated.

[0042] It can be understood that the weight of the purifier in the present invention is any value between 0.05% and 0.5% of the weight of the coal-derived oil raw material. For example, the weight of the purifier is 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, and 0.5% of the weight of the coal-derived oil raw material.

[0043] In some embodiments, the purifier includes but is not limited to carboxylic acid, phosphoric acid, carboxylate, phosphate, decalcifying agent and deferrifying agent. It is understood that the purifier includes one or more of carboxylic acid, phosphoric acid, carboxylate and phosphate, and the purifier can also be various commercially available decalcifying agent and deferrifying agent products. The purifier of the present invention has the advantages of wide selection range and low cost.

[0044] (3) Separating the coal-derived oil intermediate material obtained in step (2) to separate water, naphtha fraction, phenol oil fraction and coal-derived oil bottom oil.

[0045] The above separation process also includes heating the coal-derived oil intermediate material to make the coal-derived oil intermediate material reach a second preset temperature, the second preset temperature is 170-250°C, and preferably the second preset temperature is 170-230°C.

[0046] Specifically, the separation treatment of the coal-derived oil intermediate material includes: heating the coal-derived oil intermediate material to evaporate the water in the coal-derived oil intermediate material. Further heating the coal-derived oil intermediate material to evaporate the naphtha fraction and the phenol oil fraction in the coal-derived oil intermediate material, thereby separating the water, naphtha fraction and phenol oil fraction in the coal-derived oil intermediate material by using different heating temperatures, and the obtained bottom oil is the coal-derived oil bottom oil.

[0047] (4) subjecting the phenol oil fraction to phenol extraction to obtain crude phenol and dephenolized oil, and mixing the naphtha fraction, the dephenolized oil and the coal-derived oil bottom oil to solid-liquid separation to obtain coal-derived oil purified oil.

[0048] It can be understood that heating the coal-derived oil intermediate material to 170-250° C. is beneficial to the evaporation of phenolic substances in the coal-derived oil intermediate material, making it easier to extract the phenolic substances in the coal-derived oil intermediate material to obtain the phenol oil fraction.

[0049] In some embodiments, the second preset temperature is 170-230° C. By lowering the upper limit temperature of heating the coal-derived oil intermediate material, it is beneficial to obtain enriched oil containing phenolic substances, which is convenient for extracting crude phenol.

[0050] In some embodiments, the step of subjecting the phenol oil fraction to phenol extraction to obtain crude phenol and dephenolized oil also includes adding a phenol extraction solvent to the phenol oil fraction, wherein the phenol extraction solvent includes but is not limited to methanol, ethylene glycol, glycerol, sodium phenolate, sodium xylene sulfonate and sodium sulfite.

[0051] It can be understood that the phenol extraction treatment can be one or more of the methods such as solvent extraction, alkali extraction, Na2CO3 solution elution method and the like. The phenol extraction solvent can be one or more of the alcohol aqueous solutions such as methanol, ethylene glycol, glycerol, etc. The phenol extraction solvent can also be one or more of the aqueous solutions such as sodium phenolate, sodium xylene sulfonate, acidic sodium sulfite, etc.

[0052] In some embodiments, the coal-derived oil feedstock is mixed with the purifier for 10 to 60 minutes. Preferably, the coal-derived oil feedstock is mixed with the purifier for 20 to 40 minutes, which is beneficial to improve the overall process of coal-derived oil purification.

[0053] The present invention will be further described below in conjunction with specific embodiments.

[0054] Embodiment 1:

[0055] The medium and low temperature coal derived oil generated by coal pyrolysis in Hami, Xinjiang was selected as the experimental raw material, and the properties of the coal derived oil are listed in Table 1. The coal derived oil raw material was heated to 80°C, 0.3wt% of a commercially available YX-F-101 purifier was added, mixed and stirred for 30 minutes, and then entered into a fractionation tower to remove moisture, and a naphtha fraction of <170°C and a phenol oil fraction of 170-210°C were cut out. The phenol oil fraction was eluted with a Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >210°C, and pressure filtered using a filter press to obtain purified coal derived oil. The properties of the purified coal derived oil are listed in Table 1.

[0056] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0057] Comparative Example 1:

[0058] Comparative Example 1 is used to compare and illustrate the coal-derived oil purification method of the present invention.

[0059] The medium-low temperature coal-derived oil generated by coal pyrolysis in Hami, Xinjiang was selected as the experimental raw material. 5 kg of coal-derived oil was taken, 500 g of fresh water and 8 g of demulsifier DN-80 (commercially available) were added, and the mixture was evenly mixed and then subjected to electrical desalination. The electrical desalination temperature was 150 ° C, the pressure was 1.0 MPa, the electric field strength was 110 V / cm, and the time was 30 min. After the electrical desalination, the oil and water were separated, and the properties of the purified coal-derived oil were measured. The results are shown in Table 1.

[0060] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw material was the purified coal-derived oil in Comparative Example 1. The reaction temperature was 320 ° C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0061] Table 1

[0062]

[0063] It can be seen from the results in Table 1 that by adopting the coal-derived oil purification method of the present invention, the impurities in the purified coal-derived oil in Example 1 are greatly reduced, the metal removal rate reaches 95.6%, and the moisture content is reduced to 0.15%. In addition, due to the removal of phenolic substances, the O content of the coal-derived oil raw material is reduced to 5.94%, and the water yield of the hydrogenation reaction is reduced from 8.1% to 7.2%, which effectively reduces the occurrence of the highly exothermic reaction of hydrodeoxygenation and reduces the effects of catalyst pulverization and deactivation caused by the water generated by hydrodeoxygenation.

[0064] Embodiment 2:

[0065] Coal derived oil generated by coal gasification in Inner Mongolia was selected as the experimental raw material, and the properties of the coal derived oil are listed in Table 2. The coal derived oil raw material was heated to 90°C, 0.05wt% of a commercially available purifier with the brand name KJ-FMT3 was added, mixed and stirred for 60 minutes, and then entered into a fractionation tower to remove moisture, and a naphtha fraction of <170°C and a phenol oil fraction of 170-230°C were cut out. The phenol oil fraction was eluted with a Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >230°C, and pressure filtered using a filter press to obtain purified coal derived oil. The properties of the purified coal derived oil are listed in Table 2.

[0066] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0067] Comparative Example 2:

[0068] Comparative Example 2 is used to compare and illustrate the coal-derived oil purification method of the present invention.

[0069] The medium-low temperature coal-derived oil generated by coal gasification in Inner Mongolia was selected as the experimental raw material. 5 kg of coal-derived oil was added with 500 g of fresh water and 8 g of demulsifier DT-75 (commercially available). After mixing evenly, the mixture was subjected to electro-desalting at a temperature of 150 ° C, a pressure of 1.0 MPa, an electric field strength of 110 V / cm, and a time of 30 min. After the electro-desalting was completed, the oil-water separation was performed, and the properties of the purified coal-derived oil were measured. The results are shown in Table 2.

[0070] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw material was the purified coal-derived oil in Comparative Example 2. The reaction temperature was 320 ° C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0071] Table 2

[0072]

[0073] It can be seen from the results in Table 2 that by adopting the coal-derived oil purification method of the present invention, the impurities in the purified coal-derived oil in Example 2 are greatly reduced, the metal removal rate reaches 95.2%, and the moisture content is reduced to 0.12%. In addition, due to the removal of phenolic substances, the O content of the coal-derived oil raw material is reduced to 6.38%, and the water yield of the hydrogenation reaction is reduced from 8.3% to 7.4%, which effectively reduces the occurrence of the highly exothermic reaction of hydrodeoxygenation and reduces the effects of catalyst pulverization and deactivation caused by the water generated by hydrodeoxygenation.

[0074] Embodiment 3:

[0075] Liquefied crude oil generated by coal liquefaction in Shenmu, Shaanxi Province was selected as the experimental raw material, and the properties of the liquefied crude oil are listed in Table 3. The liquefied crude oil was pressure filtered using a filter press to obtain a coal-derived oil raw material.

[0076] The liquefied crude oil was heated to 95°C, 0.1 wt% of a commercially available KJ-FMT3 purifier was added, mixed and stirred for 45 minutes, and then entered into a fractionation tower to remove moisture, and a naphtha fraction of <170°C and a phenol oil fraction of 170-230°C were cut out. The phenol oil fraction was eluted with a Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >230°C, and filtered under pressure using a filter press to obtain purified liquefied crude oil. The properties of the purified liquefied crude oil and the phenol oil fraction before and after dephenolization are listed in Table 3.

[0077] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0078] Comparative Example 3:

[0079] Comparative Example 3 is used to compare and illustrate the coal-derived oil purification method of the present invention.

[0080] Liquefied crude oil generated by coal liquefaction in Shenmu, Shaanxi Province was selected as the experimental raw material. 5 kg of liquefied crude oil was filtered under pressure using a filter press to obtain coal-derived oil raw material. 400 g of fresh water and 6 g of demulsifier DT-75 (commercially available) were added and mixed evenly before electro-desalting. The electro-desalting temperature was 150 ° C, the pressure was 1.0 MPa, the electric field strength was 110 V / cm, and the time was 30 min. After the electro-desalting was completed, oil-water separation was performed, and the properties of the purified coal-derived oil were measured. The results are shown in Table 3.

[0081] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw material was the purified coal-derived oil of Comparative Example 3. The reaction temperature was 320 ° C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0082] Table 3

[0083]

[0084] It can be seen from the results in Table 3 that by adopting the coal-derived oil purification method of the present invention, the impurities in the purified coal-derived oil in Example 3 are greatly reduced, the metal removal rate reaches 96.6%, and the moisture content is reduced to 0.15%. In addition, due to the removal of phenolic substances, the O content of the coal-derived oil raw material is reduced to 6.41%, and the water yield of the hydrogenation reaction is reduced from 8.8% to 7.8%, which effectively reduces the occurrence of the highly exothermic reaction of hydrodeoxygenation and reduces the effects of catalyst pulverization and deactivation caused by the water generated by hydrodeoxygenation.

[0085] Embodiment 4:

[0086] The medium and low temperature coal-derived oil generated by coal pyrolysis in Hami, Xinjiang was selected as the experimental raw material, and the properties of the coal-derived oil are listed in Table 1. The coal-derived oil raw material was heated to 80°C, 0.3wt% sodium carboxylate purifier was added, mixed and stirred for 30 minutes, and then entered into a fractionation tower to remove moisture, and cut out the naphtha fraction of <170°C and the phenol oil fraction of 170-210°C. The phenol oil fraction was eluted with Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >210°C, and filtered under pressure using a filter press to obtain purified coal-derived oil. The properties of the purified coal-derived oil are listed in Table 4.

[0087] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0088] Table 4

[0089]

[0090] Embodiment 5:

[0091] The medium and low temperature coal derived oil generated by coal pyrolysis in Hami, Xinjiang was selected as the experimental raw material, and the properties of the coal derived oil are listed in Table 1. The coal derived oil raw material was heated to 80°C, 0.3wt% phosphoric acid purifier was added, mixed and stirred for 30 minutes, and then entered into a fractionation tower to remove moisture, and cut out the naphtha fraction of <170°C and the phenol oil fraction of 170-210°C. The phenol oil fraction was eluted with Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >210°C, and filtered under pressure using a filter press to obtain purified coal derived oil. The properties of the purified coal derived oil are listed in Table 5.

[0092] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0093] Table 5

[0094]

[0095]

[0096] Embodiment 6:

[0097] The medium and low temperature coal derived oil generated by coal pyrolysis in Hami, Xinjiang was selected as the experimental raw material, and the properties of the coal derived oil are listed in Table 1. The coal derived oil raw material was heated to 80°C, 0.5wt% of a commercially available YX-F-101 purifier was added, mixed and stirred for 30 minutes, and then entered into a fractionation tower to remove moisture, and a naphtha fraction of <170°C and a phenol oil fraction of 170-210°C were cut out. The phenol oil fraction was eluted with a Na2CO3 solution to extract phenolic substances in the phenol oil fraction, and then mixed with the bottom oil of >210°C, and pressure filtered using a filter press to obtain purified coal derived oil. The properties of the purified coal derived oil are listed in Table 6.

[0098] A 100 ml fixed bed experimental device was used to carry out the coal-derived oil hydrogenation experiment. The raw materials were coal-derived oil raw material and purified coal-derived oil, respectively. The reaction temperature was 320 °C and the volume space velocity was 1.0 h -1 , hydrogen partial pressure 15.0MPa, hydrogen-to-oil ratio 800.

[0099] Table 6

[0100]

[0101] Under the guidance of the above embodiments, those skilled in the art can obviously obtain various embodiments according to different values ​​of parameters such as the type of purifier, phenol extraction solvent and heating temperature selected according to the present invention.

[0102] It can be seen from the results of the above embodiments and comparative examples that the coal-derived oil purification method of the present invention can achieve the coal-derived oil purification effect and realize the demetallization, dehydration and desolidification of coal-derived oil. It can effectively reduce the oxygen content in coal-derived oil, control the strong exothermic reaction of hydrodeoxygenation, and reduce the effects of catalyst pulverization and deactivation caused by the water generated by hydrodeoxygenation. The phenolic substances extracted by the coal-derived oil purification method of the present invention can further improve the economic benefits of coal-derived oil processing; the method has a simple process, does not need to generate a large amount of coal chemical wastewater, and is environmentally friendly.

[0103] In the description of this application, words such as "first" and "second" are only used to distinguish different objects, and do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0104] Parts not described in the present invention can be implemented by those skilled in the art by referring to the existing technology.

[0105] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments should fall within the scope of protection of the claims of the present application.

Claims

1. A method for purifying coal-derived oil, It is characterized in that The following steps are included in sequence: (1) heating the coal-derived oil to a first preset temperature, wherein the first preset temperature is 60 to 200° C.; (2) adding a purifier to the coal-derived oil heated in step (1), wherein the purifier is used to separate the oil-soluble metals in the coal-derived oil; The amount of the purifier added is 0.01 to 1% by weight of the coal-derived oil; The purifying agent is carboxylic acid, phosphoric acid, carboxylate, phosphate, decalcifying agent or deironifying agent; (3) separating the coal-derived oil intermediate material obtained in step (2) to separate water, naphtha fraction, phenol oil fraction and coal-derived oil bottom oil; (4) subjecting the phenol oil fraction to phenol extraction to obtain crude phenol and dephenolized oil, and mixing the naphtha fraction, the dephenolized oil and the coal-derived oil bottom oil to solid-liquid separation to obtain coal-derived oil purified oil.

2. A method for purifying coal-derived oil according to claim 1, Features: In step (1), the first preset temperature is 80-120°C.

3. A method for purifying coal-derived oil according to claim 1, Features: In step (2), the amount of the purifier added is 0.05-0.5% of the weight of the coal-derived oil; the purifier reacts with the oil-soluble metals in the coal-derived oil at the oil-water interface, and causes the metal ions to ionize or form precipitates or chelates, thereby separating the oil-soluble metals; the purifier is a carboxylate, a phosphate, a decalcifying agent or a deironifying agent.

4. A method for purifying coal-derived oil according to claim 3, Features: The carboxylate is sodium carboxylate or potassium carboxylate; the phosphate is orthophosphate or metaphosphate.

5. A method for purifying coal-derived oil according to claim 4, Features: The commercially available brands of the purifier are YX-F-101, KJ-FMT3 or KJ-FMT3.

6. A method for purifying coal-derived oil according to claim 1, Features: In step (3), the steps of separating and treating the coal-derived oil intermediate material are as follows: heating the coal-derived oil intermediate material to evaporate the water in the coal-derived oil intermediate material; continuing to heat the coal-derived oil intermediate material to evaporate the naphtha fraction and the phenol oil fraction in the coal-derived oil intermediate material, and the bottom oil is the coal-derived oil bottom oil.

7. A method for purifying coal-derived oil according to claim 1, Features: In step (4), the phenol extraction treatment is performed by solvent extraction, alkali extraction or Na 2 CO 3 The solution was eluted with phenol.

8. A method for purifying coal-derived oil according to claim 7, Features: The solvent used for solvent extraction of phenol is methanol, ethylene glycol, glycerol, sodium phenolate, sodium xylene sulfonate or sodium sulfite.

9. A method for purifying coal-derived oil according to claim 1, Features: In step (2), the mixing time of the coal-derived oil and the purifier is 10 to 60 minutes; and in step (3), the separation treatment temperature is set to 170 to 250°C.

10. Use of the purified coal-derived oil obtained by the purification method according to any one of claims 1 to 9 in coal-derived oil hydrogenation experiments.

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