Method and system for producing environment-friendly solvent oil by hydrogenation of coal-based light liquefied oil

Abstract

The invention discloses a method and a system for producing environment-friendly solvent oil by hydrogenation of coal-based light liquefied oil. The system comprises a residual oil and coal co-hydrogenation hydrocracking unit and a fixed bed hydrofining unit, the residual oil and coal co-hydrogenation hydrocracking unit is used for preparing oil-coal slurry by mixing coal and heavy oil, and preparing light liquefied oil through a suspended bed or fluidized bed hydrogenation device; and the fixed bed hydrofining unit is used for carrying out hydrodesulfurization, denitrification, demetallization and aromatic hydrocarbon saturation on light liquefied oil generated by the suspended bed hydrogenation device. The environment-friendly solvent naphtha is produced through co-hydrogenation of coal and heavy oil, solvent naphtha production raw materials are widened, the downstream market of kerosene co-processing products is enriched, the added value of the kerosene co-processing products is increased, and meanwhile compared with direct coal liquefaction, the method has the advantages of being high in production efficiency, lower in energy consumption, low in aromatic hydrocarbon content of the products and excellent in product performance.

Description

Technical Field

[0001] The invention relates to the technical field of solvent oil production, and in particular to a method and system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil. Background Art

[0002] Solvent oil is mainly divided into petroleum-based solvent oil and coal-based solvent oil based on raw materials. Among them, it can be divided into low aromatic solvent oil, high aromatic solvent oil, etc. based on the content of aromatic components, and can be mainly divided into ordinary solvent oil and environmentally friendly solvent oil based on properties. Based on compliance with standards, it can be divided into non-standard solvent oil and standard solvent oil. In general, the development of solvent oil technology mainly presents three typical trends: first, the production technology of petroleum-based solvent oil is relatively mature, and the research and production of coal-based solvent oil technology has gradually attracted attention in the field; second, the hydrogenation production technology will continue to be the focus of research due to its strong raw material adaptability and deep refining degree; third, environmental protection will become an important consideration indicator for the quality of solvent oil and its production technology.

[0003] The current technology for producing coal-based solvent oil is mainly aimed at coal indirect liquefaction oil, including liquid wax, Fischer-Tropsch synthesis, etc.

[0004] As environmental awareness in various countries gradually increases and regulations on solvent oil standards become more and more perfect, the production of low-toxic and non-toxic environmentally friendly solvent oils and special solvent oils that meet market demand has become the development direction of solvent oils. Deep refining of solvent oils has become the most prominent problem restricting the development of environmentally friendly solvent oils. Traditional methods such as sulfonation, adsorption separation, and extraction distillation are difficult to meet the wide range of raw materials for solvent oil production and the deep refining of solvent oils; hydrogenation methods are increasingly valued by domestic and foreign scientific research institutions and manufacturers due to their good raw material adaptability, controllable hydrogenation depth, and ability to improve oil quality. In view of the fact that my country's primary energy structure is dominated by coal, practitioners in the field have gradually paid attention to the research and development of coal-based solvent oil technology.

[0005] The publication number is CN102807899A, which discloses a coal-based environmentally friendly solvent oil and a preparation method thereof, and a method for producing a coal-based environmentally friendly solvent oil by a hydrogenation method. The method first distills and separates the raw materials to obtain light oil and heavy oil; the heavy oil is hydrocracking using a suspended bed reactor, and the conditions for hydrocracking are: reaction temperature 330℃~480℃, reaction pressure 8MPa~19MPa, volume space velocity 0.3hˉ~3.0h, hydrogen oil volume ratio 500~2000:1, and then the solvent oil is produced by fixed bed hydrodesulfurization. In the above technology, the process is complicated, the raw materials need to be pretreated, the production efficiency is not high, and a large amount of intermediate products in the direct coal liquefaction process need to be recycled and processed as solvents. The generated solvent oil has a large density and a high aromatic content.

[0006] In summary, the defects of the prior art are that shale oil or coal tar as raw materials need to be pretreated.

[0007] The process is complex, using coal direct liquefaction oil as raw material. The intermediate product in the production process needs to be recycled as solvent oil, resulting in low production efficiency and high energy consumption. Summary of the invention

[0008] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a method and system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil. The method realizes the co-hydrogenation of coal and heavy oil to produce environmentally friendly solvent oil, broadens the raw materials for solvent oil production, enriches the downstream market for kerosene co-refining products, and increases the added value of kerosene co-refining products. At the same time, compared with direct coal liquefaction, the production efficiency is high and the energy consumption is lower, and the product has the characteristics of low aromatic content and excellent product performance.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil comprises the following steps:

[0011] Step 1, producing light liquefied oil by suspended bed hydrogenation;

[0012] Coal and heavy oil are mixed to prepare oil-coal slurry, and light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; the light liquefied oil produced through the suspended bed or ebullating bed hydrogenation device includes two parts, one part is the product collected by the cold low-pressure separator 8, and the other part is the product collected by the hot high-pressure separator 5, the product collected by the hot high-pressure separator 5 enters the vacuum distillation system, after being reduced pressure by the vacuum system 6, enters the vacuum tower 9 for fractional distillation to obtain the light liquefied oil;

[0013] Step 2, fixed bed hydrofining;

[0014] The product collected by the fixed bed hydrogenation cold low-pressure separator 8 and the other part of the product collected by the hot high-pressure separator 5 are mixed in a mixer 10 at a ratio of 60-80:40-20 as raw materials; and then reacted in the fixed bed reactor 12 and the fixed bed reactor 2 13;

[0015] In the fixed bed reactor 12 and the fixed bed reactor 2 13, the reaction pressure is 8.0-18.0 MPa, the reaction temperature is 330-420°C, and the space velocity is 0.3-2.0 h -1 , the volume ratio of hydrogen to oil is 400:1 to 1800:1, and the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst to obtain the product;

[0016] Step 3, distillation separation;

[0017] The distillation separation uses the product after hydrogenation in the fixed bed reactor 12 and the fixed bed reactor 2 13 as raw materials, and performs fractionation in the distillation tower 16 to cut the fractions in different boiling point ranges, thereby obtaining environmentally friendly solvent oils of different grades.

[0018] Furthermore, in step 1, the suspended bed hydrogenation to produce light liquefied oil uses coal and heavy oil as raw materials after being slurried in a certain ratio, and the method also includes: raw material preparation, coal tar needs to be pretreated, and after reaching the conditions, it meets the feed requirements;

[0019] Coal and heavy oil in the feed pump 17 are mixed into an oil-coal slurry in a certain proportion, in which coal powder accounts for 10% to 50%, and light liquefied oil is produced through a suspended bed or an ebullating bed hydrogenation device, that is, in the reactor 4, the conditions for hydrocracking are a reaction pressure of 12.0 to 22.0 MPa, a reaction temperature of 450 to 470°C, an air velocity of 0.5 to 1.0 h, a hydrogen-oil volume ratio of 500:1 to 2000:1, and an iron-based catalyst.

[0020] In step 1, the distillation process in the vacuum distillation system specifically uses the bottom product of the thermal high fractionation 5 of the suspended bed hydrogenation device as raw material, reduces the pressure to normal pressure through the vacuum system 6, enters the vacuum tower 9, and separates the components below 450°C.

[0021] In the step 1, the product coming out of the bottom of the cold high-pressure separator 8 and the product coming out of the bottom of the hot high-pressure separator 5 are decompressed by the decompression system 6 and distilled by the decompression tower 9 to obtain light liquefied oil, which is then mixed in the mixer 10.

[0022] The fixed bed hydrorefining in step 2 uses the prepared light liquefied oil as raw material, passes through a fixed bed reactor 12 and a fixed bed reactor 2 13, and completes desulfurization, denitrogenation, deoxygenation and aromatic saturation. The conditions of the fixed bed reactor 12 and the fixed bed reactor 2 13 are reaction pressure 8.0-18.0 MPa, reaction temperature 330-420°C, space velocity 0.3-2.0h, hydrogen-oil volume ratio 400:1-1800:1, and the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst.

[0023] Furthermore, the distillation separation step in step 3 is to cut the product obtained by fixed bed hydrogenation on a real boiling point cutting device, and classify it according to the distillation range of 60-90°C, 80-120°C or 140-220°C to produce solvent oil products of different grades.

[0024] A system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil, comprising a residual oil and coal co-hydrogenation stream hydrocracking unit and a fixed bed hydrorefining unit;

[0025] The residual oil and coal co-hydrogenation stream hydrocracking unit is used to prepare oil-coal slurry by mixing coal and heavy oil, and produce light liquefied oil through a suspended bed or ebullating bed hydrogenation device;

[0026] The fixed bed hydrorefining unit is used for carrying out hydrodesulfurization, denitrogenation, demetallization and aromatic saturation on the light liquefied oil produced by the suspended bed hydrogenation device.

[0027] The residue oil and coal co-hydrogenation stream hydrocracking unit comprises a new hydrogen compressor 1, which pressurizes hydrogen and then enters a preheater 2 for preheating, wherein the output end of the preheater 2 is connected to the input end of the preheater 3, the output end of the preheater 3 is connected to the input end of the reactor 4, and the top product output end of the reactor 4 is connected to the input end of the hot high-fraction separator 5 for separation;

[0028] The light components separated by the hot high fraction separator 5 enter the cold high pressure separator 8 in the form of gas after being cooled by the cooler 7 from the top of the hot high fraction separator 5;

[0029] The heavy component is discharged from the bottom of the hot high fraction separator 5, and after being decompressed by the decompression system 6, it enters the vacuum tower 9 for fractionation. After fractionation, the component with a temperature less than 450°C is mixed with the bottom product of the cold high fraction 8 in the mixer 10;

[0030] The fixed bed hydrotreating unit uses the light distillate oil produced by the suspended bed hydrogenation device as raw material, which is heated by the heater 11 and then enters the fixed bed reactor 12 and the fixed bed reactor 2 13 for reaction. The output end of the fixed bed reactor 12 is connected to the input end of the fixed bed reactor 2 13, and the output end of the fixed bed reactor 2 13 is connected to the separator 14. The separator 14 separates the gas and discharges it from the top of the separator 14. The liquid enters the stripping tower 15 for gas stripping. After gas stripping, the liquid is discharged from the bottom of the stripping tower 15 and enters the distillation tower 16 for oil product cutting. The gas is discharged to the venting pipeline.

[0031] The heavy oil and coal are prepared in a certain ratio, and the prepared oil-coal slurry is mixed with the hydrogen from the new hydrogen compressor 1 through the feed pump 17.

[0032] Furthermore, in step 1, the suspended bed or ebullating bed hydrogenation device includes a feed system, a reactor system, a high-pressure separator system, and a low-pressure separator.

[0033] Furthermore, the raw material preparation system of the suspended bed hydrogenation device includes a coal mill, a coal powder screening machine, a coal powder pneumatic conveying system, an additive online feeding system, an agitator, a raw oil pump, an oil slurry circulation pump and a finished oil slurry conveying pump.

[0034] Furthermore, the feed system of the suspended bed hydrogenation device includes a high-pressure feed pump 17 , an oil preheater 3 , a hydrogen preheater 2 , and a hydrogen compressor 1 .

[0035] Furthermore, the suspended bed hydrogenation device reactor includes a reactor 4.

[0036] Furthermore, the high-pressure separation system of the suspended bed hydrogenation device includes a hot high-pressure separator 5 and a cold high-pressure separation system 8 .

[0037] Furthermore, the decompression system of the suspended bed hydrogenation unit includes a hot low-pressure separation system 6 and a decompression tower 9 .

[0038] Furthermore, the fixed bed hydrotreating unit includes a reaction system, a separation system, a gas stripping system and a fractionation system.

[0039] The reaction system is used to perform deep desulfurization, denitrogenation, metal removal and aromatic saturation on light liquefied oil to produce target product oil.

[0040] The separation system is used to separate gas and liquid from the product oil produced from the reactor 12 and the reactor 13. The main equipment is the cold high-separation separator 14, and the gas is discharged from the top of the cold high-separation separator 14. The liquid is discharged from the bottom of the cold high-separation separator 14 and enters the gas stripping system after decompression.

[0041] The gas stripping system is mainly used to remove the hydrogen sulfide dissolved in the product oil by introducing nitrogen through the stripping tower 15 to further reduce the hydrogen sulfide gas dissolved in the target product oil.

[0042] The temperature of the decompression system 6 is 80-100 degrees Celsius and the pressure is 0.2-0.5MPa;

[0043] The vacuum degree of the vacuum tower 9 is 2-13 Torr, and the temperature is 120-330 degrees Celsius.

[0044] Beneficial effects of the present invention:

[0045] The present invention uses coal and heavy oil to co-hydrogenate to produce environmentally friendly solvent oil, fully utilizes the synergistic effect in the coal and heavy oil hydrogenation process, broadens the production raw materials of coal-based environmentally friendly solvent oil, extends the industrial chain of coal and heavy oil hydrogenation, and increases the added value of coal and heavy oil hydrogenation products. At the same time, the energy consumption in the processing process is low and the efficiency is high. The produced coal-based environmentally friendly solvent oil has a high cycloalkane content, a low aromatic content, and a low sulfur and nitrogen content, and has excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with embodiments: Figure 1As shown, this embodiment discloses a system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil, which mainly includes a residual oil and coal co-hydrogenation stream hydrocracking unit and a fixed bed hydrofining unit; the residual oil and coal co-hydrogenation stream hydrocracking unit is used to mix coal and heavy oil to prepare oil-coal slurry, and produce light liquefied oil through a suspended bed or ebullating bed hydrogenation device;

[0048] The fixed bed hydrorefining unit is used for hydrodesulfurization, denitrogenation, demetallization and aromatic saturation of light liquefied oil produced by the suspended bed hydrogenation device. Among them, the residual oil and coal co-hydrogenation flow hydrocracking unit is preheated by hydrogen after being pressurized by the new hydrogen compressor 1, mixed with oil-coal slurry after being pressurized by the feed pump and enters the preheater 3, heated to about 360°C and enters the reactor 4 for reaction, and the reaction product enters the hot high-separation separator 5 from the top of the reactor 4 for separation, and the light component enters the cold high-pressure separator 8 in the form of gas after being cooled by the cooler 7 from the top of the hot high-separation 5; the heavy component is discharged from the bottom of the hot high-separation 5, and after being decompressed by the decompression system 6, it enters the decompression tower for fractionation, and the component less than 450°C after fractionation is mixed with the bottom product of the cold high-separation 8 at the mixer 10.

[0049] The fixed bed hydrotreating unit uses the light distillate oil produced by the suspended bed hydrogenation device as raw material, which is heated by the heater 11 and then enters the fixed bed reactor 12 and the fixed bed reactor 2 13 for reaction, and then enters the separator 14 for separation. The gas is discharged from the top of the separator 14, and the liquid enters the stripping tower 15 for gas stripping. After gas stripping, the liquid is discharged from the bottom of the stripping tower and enters the distillation tower 16 for oil product cutting. The gas is discharged to the venting pipeline.

[0050] The heavy oil and coal are prepared in a certain proportion, and the prepared oil-coal slurry is mixed with the hydrogen from the new hydrogen compressor 1 through the feed pump 17, and enters the heater 2 and the heater 3 for heating. After reaching 360°C, it enters the suspended bed reactor 4 for reaction. The material coming out of the top of the suspended bed reactor 4 enters the hot high-separation separator 5 for gas-liquid separation, and the light component enters the cold high-separation separator 8 from the top of the hot high-separation separator 5 through the cooler 7 for gas-liquid separation. The separated gas is discharged from the top of the cold high-separation separator 8 to the vent tail gas, and the heavy component enters the vacuum tower from the bottom of the hot high-separation separator 5 after passing through the decompression system. 9 is decompressed, after decompression, light oil products of a certain fraction are selected and mixed with the bottom liquid of the cold high fraction 8 in the mixer 10, and enter the heater 11 for heating. After being heated to a certain temperature, they enter the fixed bed reactor 12 and the fixed bed reactor 2 13 for reaction, and the product coming out of the fixed bed reactor 2 13 enters the separator 14 for separation, and the gas is discharged from the top to the vent tail gas. After decompression, the liquid enters the gas tower 15 for gasification, and the gas at the top of the gas tower 15 is discharged to the vent tail gas. The bottom liquid enters the vacuum tower 16 for oil product separation to obtain the target product oil.

[0051] A method for preparing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil:

[0052] First way:

[0053] When the raw material is a full fraction of coal tar, the method mainly includes suspended bed hydrocracking or ebullating bed hydrogenation, fixed bed hydrofining and distillation separation steps, specifically:

[0054] Step 1. Raw material pretreatment: first, the raw material is pretreated by dehydration and removal of mechanical impurities, and then distilled to separate light oil and heavy oil. The cutting temperature point of light oil and heavy oil can be determined according to the properties of the full fraction of coal tar oil and the distribution characteristics of the fraction, at any temperature between 200°C and 440°C.

[0055] Step 2. Suspended bed hydrocracking: The heavy oil is hydrocracking using a suspended bed reactor, wherein the suspended bed reactor is an independent vacuum tower 9, and the hydrocracking conditions are reaction pressure 12.0-22.0 MPa, reaction temperature 450-470°C, and space velocity 0.5-1.0 h -1 The volume ratio of hydrogen to oil is 500:1 to 2000:1, and the catalyst is an iron-based catalyst. The particle diameter of the catalyst is a powder particle less than 10 to 40 um, and the addition amount of the hydrocracking catalyst is 0.5% to 2%.

[0056] Step 3. Fixed bed hydrorefining, the light liquefied oil obtained by suspended bed hydrocracking and the light liquefied oil obtained by distillation of the suspended bed hydrogenation heat high-fraction product are mixed in a certain proportion as a raw material, and passed through a fixed bed reactor 12 and a fixed bed reactor 2 13 to complete desulfurization, denitrogenation, deoxygenation and aromatic saturation. The conditions of fixed bed hydrogenation are reaction pressure 8.0-18.0 MPa, reaction temperature 330-420°C, space velocity 0.3-2.0 h -1 , hydrogen-oil volume ratio 400:1-1800:1, the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst;

[0057] Step 4. Distillation is to cut the product obtained by fixed bed hydrogenation on a real boiling point cutting device, and classify it according to the distillation range of 60-90°C, 80-120°C or 140-220°C to produce solvent oil products of different grades.

[0058] Through the above steps, the target product solvent oil has low aromatic content, sulfur content that meets the requirements, good light stability, etc., meeting the requirements of environmentally friendly solvent oil.

[0059] Second way:

[0060] When the raw material is a mixture of coal and oil, the method mainly includes suspended bed hydrocracking, fixed bed hydrofining and distillation separation steps, specifically:

[0061] Step 1. Coal and heavy oil are prepared into oil-coal slurry in a ratio of 10% to 50% of coal powder, and a certain proportion of powder catalyst is added, the amount of catalyst added is between 1% and 2%. After being pressurized by the high-pressure feed pump 17, it is heated by the preheater 3 and enters the reactor 4. The conditions for hydrocracking are reaction pressure 12.0 to 22.0 MPa, reaction temperature 450 to 470°C, and space velocity 0.5 to 1.0 h -1 , the volume ratio of hydrogen to oil is 500:1 to 2000:1, and the catalyst is an iron-based catalyst.

[0062] Step 2. Fixed bed hydrogenation device, the light liquefied oil obtained by suspended bed hydrocracking and the light liquefied oil obtained by distillation of the suspended bed hydrogenation hot high-fraction product are mixed in a certain proportion as raw materials, and cut through a distillation device, and the fraction between 180 and 420°C is selected, and the fraction is passed through a fixed bed reactor 12 and a fixed bed reactor 2 13 to complete desulfurization, denitrogenation, deoxygenation and aromatic saturation. The conditions for fixed bed hydrogenation are reaction pressure 8.0 to 18.0 MPa, reaction temperature 330 to 420°C, and space velocity 0.3 to 2.0 h -1 The volume ratio of hydrogen to oil is 400:1 to 1800:1, and the catalyst is a Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst.

[0063] Step 3. distillation is to cut the product obtained by fixed bed hydrogenation on a real boiling point cutting device, and classify it according to the distillation range of 60-90°C, 80-120°C or 140-220°C to prepare solvent oil products of different grades.

[0064] Examples;

[0065] Coal tar was selected as the raw material. The properties of the coal-based oil raw material after dehydration and mechanical impurity removal pretreatment are shown in Table 1. After passing through the suspended bed hydrogenation device, i.e., reactor 4, the reaction conditions were reaction pressure 12.0-22.0 MPa, reaction temperature 450-470°C, and space velocity 0.5-1.0 h -1 , the volume ratio of hydrogen to oil is 500:1 to 2000:1, and the catalyst is an iron-based catalyst. The light liquefied oil produced is used as the raw material of the fixed bed hydrogenation unit, and after being hydrocracking, hydrofining and hydromodification in the fixed bed reactor 12 and the fixed bed reactor 2 13, sulfur, nitrogen, oxygen and metals are removed;

[0066] The reaction conditions are reaction pressure 8.0~18.0MPa, reaction temperature 330~420℃, space velocity 0.3~2.0h -1, hydrogen-oil volume ratio 400:1-1800:1, catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst. Coal tar hydrorefining liquefied oil is obtained.

[0067] Embodiment 1:

[0068] Step 1, suspended bed hydrogenation to produce light liquefied oil; coal and heavy oil are mixed to prepare oil-coal slurry, with coal powder accounting for 10%; light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; that is, in reactor 4, the reaction conditions are reaction pressure 20MPa, reaction temperature 460℃, space velocity 0.5h -1 , hydrogen oil volume ratio 1500:1

[0069] The light liquefied oil produced by the suspended bed or fluidized bed hydrogenation device includes two parts, one part is the product collected by the cold low-pressure separator 8, and the other part is the product collected by the hot high-pressure separator 5. The product collected by the hot high-pressure separator 5 enters the vacuum distillation system, and after being decompressed by the vacuum system 6, the temperature of the vacuum system 6 is 80 degrees Celsius and the pressure is 0.2MPa; it enters the vacuum tower 9 for fractional distillation to obtain the light liquefied oil; the vacuum degree of the vacuum tower 9 is 2Torr and the temperature is 120 degrees Celsius.

[0070] Step 2, fixed bed hydrofining;

[0071] The product collected by the fixed bed hydrogenation cold low-pressure separator 8 and the other part of the product collected by the hot high-pressure separator 5 are mixed in a mixer 10 at a ratio of 60:40 as raw materials at a fraction below 450°C; and then reacted in the fixed bed reactor 12 and the fixed bed reactor 2 13;

[0072] In the fixed bed reactor 12, the reaction pressure is 12 MPa, the reaction temperature is 360°C, and the space velocity is 0.5 h -1 , the volume ratio of hydrogen to oil is 1000:1, the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, and the product is obtained;

[0073] In the fixed bed reactor 2 13, the reaction pressure is 12 MPa, the reaction temperature is 360°C, and the space velocity is 0.5 h -1 , the volume ratio of hydrogen to oil is 1000:1, the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, and the product is obtained;

[0074] Step 3, distillation separation;

[0075] The distillation separation is carried out by using the product after hydrogenation in the fixed bed reactor 12 and the fixed bed reactor 2 13 as raw materials, and is fractionated by distillation in the distillation tower 16 to obtain environmentally friendly solvent oils of different grades.

[0076] Embodiment 2:

[0077] Step 1, suspended bed hydrogenation to produce light liquefied oil; coal and heavy oil are mixed to prepare oil-coal slurry, with coal powder accounting for 20%; light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; that is, in reactor 4, the reaction conditions are reaction pressure 20MPa, reaction temperature 465℃, space velocity 0.5h -1 , hydrogen oil volume ratio 1500:1

[0078] The light liquefied oil produced by the suspended bed or fluidized bed hydrogenation device includes two parts, one part is the product collected by the cold low-pressure separator 8, and the other part is the product collected by the hot high-pressure separator 5. The product collected by the hot high-pressure separator 5 enters the vacuum distillation system, and after being decompressed by the vacuum system 6, the temperature of the vacuum system 6 is 90 degrees Celsius and the pressure is 0.3MPa; it enters the vacuum tower 9 for fractional distillation to obtain the light liquefied oil; the vacuum tower 9 has a vacuum degree of 6Torr and a temperature of 200 degrees Celsius.

[0079] Step 2, fixed bed hydrofining;

[0080] The product collected by the fixed bed hydrogenation cold low-pressure separator 8 and the other part of the product collected by the hot high-pressure separator 5 are mixed in a mixer 10 at a ratio of 60:40 as raw materials at a fraction below 450°C; and then reacted in the fixed bed reactor 12 and the fixed bed reactor 2 13;

[0081] In the fixed bed reactor 12, the reaction pressure is 18 MPa, the reaction temperature is 370°C, and the space velocity is 0.5 h -1 , the volume ratio of hydrogen to oil is 1000:1, the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, and the product is obtained;

[0082] In the fixed bed reactor 2 13, the reaction pressure is 16 MPa, the reaction temperature is 370°C, and the space velocity is 0.5 h -1 , the volume ratio of hydrogen to oil is 1000:1, the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, and the product is obtained;

[0083] Step 3, distillation separation;

[0084] The distillation separation is carried out by using the product after hydrogenation in the fixed bed reactor 12 and the fixed bed reactor 2 13 as raw materials, and is fractionated by distillation in the distillation tower 16 to obtain environmentally friendly solvent oils of different grades.

[0085] Embodiment 3:

[0086] Step 1, suspended bed hydrogenation to produce light liquefied oil; coal and heavy oil are mixed to prepare oil-coal slurry, with coal powder accounting for 30%; light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; that is, in reactor 4, the reaction conditions are reaction pressure 20MPa, reaction temperature 465℃, space velocity 0.5h -1 , hydrogen oil volume ratio 1500:1

[0087] The light liquefied oil produced by the suspended bed or fluidized bed hydrogenation device includes two parts, one part is the product collected by the cold low-pressure separator 8, and the other part is the product collected by the hot high-pressure separator 5. The product collected by the hot high-pressure separator 5 enters the vacuum distillation system, and after being decompressed by the vacuum system 6, the temperature of the vacuum system 6 is 80 degrees Celsius and the pressure is 0.2MPa; it enters the vacuum tower 9 for fractional distillation to obtain the light liquefied oil; the vacuum degree of the vacuum tower 9 is 2Torr and the temperature is 120 degrees Celsius.

[0088] Step 2, fixed bed hydrofining;

[0089] The product collected by the fixed bed hydrogenation cold low-pressure separator 8 and the other part of the product collected by the hot high-pressure separator 5 are mixed in a mixer 10 at a ratio of 80:20 as raw materials; and then reacted in the fixed bed reactor 12 and the fixed bed reactor 2 13;

[0090] In the fixed bed reactor 12, the reaction pressure is 12 MPa, the reaction temperature is 370°C, and the space velocity is 0.5 h -1 , hydrogen-oil volume ratio 900:1, catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, to obtain the product;

[0091] In the fixed bed reactor 2 13, the reaction pressure is 18 MPa, the reaction temperature is 370°C, and the space velocity is 0.5 h -1 , hydrogen-oil volume ratio 900:1, catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, to obtain the product;

[0092] Step 3, distillation separation;

[0093] The distillation separation is carried out by using the product after hydrogenation in the fixed bed reactor 12 and the fixed bed reactor 2 13 as raw materials, and is fractionated by distillation in the distillation tower 16 to obtain environmentally friendly solvent oils of different grades.

[0094] Example 4

[0095] Step 1, suspended bed hydrogenation to produce light liquefied oil; coal and heavy oil are mixed to prepare oil-coal slurry, with coal powder accounting for 50%; light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; that is, in reactor 4, the reaction conditions are reaction pressure 20MPa, reaction temperature 470℃, space velocity 0.5h-1 , hydrogen oil volume ratio 1500:1

[0096] The light liquefied oil produced by the suspended bed or fluidized bed hydrogenation device includes two parts, one part is the product collected by the cold low-pressure separator 8, and the other part is the product collected by the hot high-pressure separator 5. The product collected by the hot high-pressure separator 5 enters the vacuum distillation system, and after being decompressed by the vacuum system 6, the temperature of the vacuum system 6 is 100 degrees Celsius and the pressure is 0.5MPa; it enters the vacuum tower 9 for fractional distillation to obtain the light liquefied oil; the vacuum degree of the vacuum tower 9 is 13Torr and the temperature is 330 degrees Celsius.

[0097] Step 2, fixed bed hydrofining;

[0098] The product collected by the fixed bed hydrogenation cold low-pressure separator 8 and the other part of the product collected by the hot high-pressure separator 5 are mixed in a mixer 10 at a ratio of 80:20 as raw materials; and then reacted in the fixed bed reactor 12 and the fixed bed reactor 2 13;

[0099] In the fixed bed reactor 12, the reaction pressure is 12 MPa, the reaction temperature is 380°C, and the space velocity is 0.5 h -1 , hydrogen-oil volume ratio 900:1, catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, to obtain the product;

[0100] In the fixed bed reactor 2 13, the reaction pressure is 18 MPa, the reaction temperature is 380°C, and the space velocity is 0.5 h -1 , hydrogen-oil volume ratio 900:1, catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst, to obtain the product;

[0101] Step 3, distillation separation;

[0102] The distillation separation is carried out by using the product after hydrogenation in the fixed bed reactor 12 and the fixed bed reactor 2 13 as raw materials, and is fractionated by distillation in the distillation tower 16 to obtain environmentally friendly solvent oils of different grades.

[0103] The details are shown in Table 1-5.

[0104] Basic properties of coal tar

[0105]

[0106]

[0107] Table 1 Basic properties of raw coal

[0108]

[0109] Table 2 Basic properties of raw heavy oil

[0110]

[0111]

[0112] Kerosene co-refining hydrogenation reaction conditions

[0113] Table 3, Suspended Bed Implementation Cases

[0114]

[0115] Fixed bed hydrogenation reaction conditions

[0116] Table 4 Fixed bed reaction case

[0117]

[0118] Reaction product properties

[0119] Table 5 Properties of reaction products

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[0121]

Claims

1. A method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil, characterized in that: The following steps are involved: Step 1, producing light liquefied oil by suspended bed hydrogenation; Coal and heavy oil are mixed to prepare oil-coal slurry, and light liquefied oil is produced through a suspended bed or ebullating bed hydrogenation device; the light liquefied oil produced through the suspended bed or ebullating bed hydrogenation device includes two parts, one part is the product collected by a cold low-pressure separator (8), and the other part is the product collected by a hot high-pressure separator (5); the product collected by the hot high-pressure separator (5) enters a vacuum distillation system, is decompressed by a vacuum system (6), and then enters a vacuum tower (9) for fractional distillation to obtain light liquefied oil; Step 2, fixed bed hydrofining; The product collected by the fixed bed hydrogenation cold low-pressure separator (8) and the other part of the product collected by the hot high-pressure separator (5) are mixed in a mixer (10) at a ratio of 60-80:40-20 as raw materials; and then reacted in a fixed bed reactor 1 (12) and a fixed bed reactor 2 (13) to obtain a product; Step 3, distillation separation; The distillation separation is carried out by using the product after hydrogenation in the fixed bed reactor 1 (12) and the fixed bed reactor 2 (13) as raw materials, and fractionating the product through distillation in the distillation tower (16), and cutting the fractions in different boiling point ranges, thereby obtaining environmentally friendly solvent oils of different brands.

2. The method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 1, characterized in that: In step 1: Coal and heavy oil in the feed pump (17) are mixed into an oil-coal slurry in a certain ratio, wherein the coal powder accounts for 10% to 50%, and light liquefied oil is produced through a suspended bed or an ebullating bed hydrogenation device; that is, the conditions for hydrocracking in the reactor (4) are a reaction pressure of 12.0 to 22.0 MPa, a reaction temperature of 450 to 470°C, an air velocity of 0.5 to 1.0 h, a hydrogen-to-oil volume ratio of 500:1 to 2000:1, and an iron-based catalyst.

3. The method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 1, characterized in that: In the step 1, the distillation process in the vacuum distillation system is specifically to use the bottom product of the hot high fraction (5) of the suspended bed hydrogenation device as raw material, reduce the pressure to normal pressure through the vacuum system (6), and enter the vacuum tower (9) to separate the components below 450° C.; The product from the bottom of the cold high-pressure separator (8) and the product from the bottom of the hot high-pressure separator (5) are decompressed by the decompression system (6) and distilled in the decompression tower (9) to obtain light liquefied oil, which is then mixed in the mixer (10).

4. The method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 1, characterized in that: In the step 2, the fixed bed hydrorefining uses the prepared light liquefied oil as a raw material, passes through a fixed bed reactor 1 (12) and a fixed bed reactor 2 (13), and completes desulfurization, denitrogenation, deoxygenation and aromatic saturation. The conditions of the fixed bed reactor 1 (12) and the fixed bed reactor 2 (13) are reaction pressure 8.0-18.0 MPa, reaction temperature 330-420° C., space velocity 0.3-2.0 h, hydrogen-oil volume ratio 400:1-1800:1, and the catalyst is Ni-W, Ni-Mo, or Ni-W-Mo series hydrorefining catalyst.

5. The method for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 1, characterized in that: The distillation separation step in step 3 is to cut the product obtained by fixed bed hydrogenation on a real boiling point cutting device, and classify it according to the distillation range of 60-90°C, 80-120°C or 140-220°C to produce solvent oil products of different grades.

6. A system for producing environmentally friendly solvent oil by hydrogenating light liquefied coal oil for implementing the method described in any one of claims 1 to 5, characterized in that: It includes a residual oil and coal co-hydrogenation stream hydrocracking unit and a fixed bed hydrofining unit; The residual oil and coal co-hydrogenation stream hydrocracking unit is used to prepare oil-coal slurry by mixing coal and heavy oil, and produce light liquefied oil through a suspended bed or ebullating bed hydrogenation device; The fixed bed hydrorefining unit is used for carrying out hydrodesulfurization, denitrogenation, demetallization and aromatic saturation on the light liquefied oil produced by the suspended bed hydrogenation device.

7. A system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 6, characterized in that: The residual oil and coal co-hydrogenation stream hydrocracking unit comprises a new hydrogen compressor (1), the new hydrogen compressor (1) pressurizes hydrogen and then enters a preheater (2) for preheating, the output end of the preheater (2) is connected to the input end of the preheater (3), the output end of the preheater (3) is connected to the input end of the reactor (4), and the top product output end of the reactor (4) is connected to the input end of a hot high-fraction separator (5) for separation; The light components separated by the hot high fraction separator (5) are cooled in the form of gas from the top of the hot high fraction separator (5) by the cooler (7) and then enter the cold high pressure separator (8); The heavy component is discharged from the bottom of the hot high fraction separator (5), decompressed by the decompression system (6), and then enters the decompression tower (9) for fractionation. The components with a temperature less than 450° C. after fractionation are mixed with the bottom product of the cold high fraction (8) in the mixer (10); The fixed bed hydrotreating unit uses the light distillate oil produced by the suspended bed hydrogenation device as raw material, which is heated by a heater (11) and then enters a fixed bed reactor 1 (12) and a fixed bed reactor 2 (13) for reaction. The output end of the fixed bed reactor 1 (12) is connected to the input end of the fixed bed reactor 2 (13), and the output end of the fixed bed reactor 2 (13) is connected to a separator (14). The separator (14) separates gas and discharges it from the top of the separator (14). The liquid enters a stripping tower (15) for stripping. After stripping, the liquid is discharged from the bottom of the stripping tower (15) and enters a distillation tower (16) for oil product cutting. The gas is discharged to a venting pipeline.

8. A system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 7, characterized in that: The heavy oil and coal are prepared in a certain ratio, and the prepared oil-coal slurry is mixed with the hydrogen from the new hydrogen compressor (1) through a feed pump (17).

9. A system for producing environmentally friendly solvent oil by hydrogenating coal-based light liquefied oil according to claim 7, characterized in that: The temperature of the decompression system (6) is 80-100 degrees Celsius and the pressure is 0.2-0.5 MPa; The vacuum degree of the vacuum tower (9) is 2-13 Torr, and the temperature is 120-330 degrees Celsius.

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