CN105778995B - The method and its equipment of Low Temperature Fischer Tropsch artificial oil and inferior feedstock oil Unionfining production fine-quality diesel oil - Google Patents

Abstract

The invention discloses a method and equipment for producing high-quality diesel oil through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil. 2) Mix the hydrofinishing reactant obtained in step 1) with inferior raw material oil and Fischer-Tropsch wax oil to obtain a mixed oil, and then use the gas-liquid countercurrent hydrogenation method to mix the mixed oil 3) using the gas-liquid countercurrent hydrogenation method to carry out hydrocracking and isomerization reaction on the hydrofinishing reactant obtained in step 2); 4) fractionating the liquid-phase production oil obtained in step 3), Get premium diesel. The invention provides a process for producing high-quality diesel oil by combining liquid-phase hydrogenation and vapor-liquid countercurrent hydrogenation to process Fischer-Tropsch synthetic oil and inferior diesel oil, and obtain diesel oil with qualified density and high cetane number.

Description

Method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil to produce high-quality diesel oil and its equipment

technical field

The invention relates to diesel production technology, in particular to a method and equipment for producing high-quality diesel through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil.

Background technique

With the shortage of petroleum resources and the increasingly stringent environmental regulations around the world, the development of clean alternative energy technologies has gradually attracted attention, among which Fischer-Tropsch synthesis technology has attracted much attention because it can use coal, natural gas, biomass and other raw materials to produce high-clean fuels. focus on. Fischer-Tropsch synthesis technology can be divided into high-temperature Fischer-Tropsch synthesis technology and low-temperature Fischer-Tropsch synthesis technology according to the reaction temperature. The composition of the Fischer-Tropsch synthesis product is quite different from that of petroleum. Due to the restriction of the Anderson-Schulz-Flory rule, the product is mainly a complex mixture of hydrocarbons containing C ₄ -C ₇₀ and a small amount of oxygen-containing compounds. Nitrogen, metal-free, low aromatics, etc. Among them, the low-temperature Fischer-Tropsch synthesis products are mainly composed of linear alkanes and olefins, and contain a small amount of oxygen-containing organic compounds. The low-temperature Fischer-Tropsch synthesis product contains nearly 40% wax. Although the cetane number exceeds 70, the freezing point and pour point are too high, and the cold flow performance is too poor to be directly used as transportation fuel. One of the main purposes of Fischer-Tropsch synthesis technology is to produce high-quality diesel oil. Each fraction in the Fischer-Tropsch synthesis product must undergo corresponding hydrogenation and upgrading to obtain qualified products. The low-temperature Fischer-Tropsch synthesis product has the characteristics of high linear alkanes, high freezing point, and low density, which makes the hydrogenated diesel fraction have a high freezing point and low density, and cannot be directly sold as commercial diesel. At the same time, in the process of refinery processing, inferior secondary processed diesel oil contains a large amount of aromatics and has a high density, but its cetane number is very low. The content of impurities such as sulfur, nitrogen and aromatics, and the gaseous impurities such as H ₂ S and NH ₃ generated during the hydrogenation process compete for adsorption on the active center of the catalyst surface, which has a greater impact on hydrocracking and isomerization. Inhibition, the reaction temperature required for hydrocracking will be high, which in turn will affect the service life of the catalyst, energy consumption and operating costs.

There are some reports about how to utilize low-temperature Fischer-Tropsch synthesis products to produce diesel oil in the prior art, such as: Chinese patent CN10313468A discloses a kind of low-temperature Fischer-Tropsch synthetic oil hydrofinishing and/or hydroisomerization cracking process, the method is Hydrofining or hydrocracking unit adopts liquid phase hydrogenation and lower feed mode, the disadvantage of this method is that the obtained diesel oil has a low density, only 0.7586g/cm ³ ; a kind of production intermediate The method of distillate oil, the method is to carry out hydrocracking at least part of the synthetic oil, and then separate the kerosene fraction in it, then carry out hydrocracking of the tail oil, and then separate the kerosene fraction in the product, wherein the density of the diesel fraction is 0.78 g/cm ³ , and the freezing point is -28～0℃. The disadvantage of this method is that the density of the diesel fraction is low, which cannot meet the diesel index for vehicles.

Contents of the invention

The object of the present invention is to provide a method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil. The diesel oil obtained by the method has a qualified density and a high cetane number.

In order to achieve the above object, the method for producing high-quality diesel oil through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil designed by the present invention comprises the following steps:

1) The Fischer-Tropsch diesel is subjected to hydrogen-mixing treatment, and after saturated hydrogen dissolution, the liquid-phase circulating hydrogenation method is used for hydrofining;

2) Mixing the hydrorefining reactant obtained in step 1) with inferior raw material oil and Fischer-Tropsch wax oil to obtain a mixed oil, and then using a gas-liquid countercurrent hydrogenation method to carry out hydrofining on the mixed oil;

3) Continue to use the gas-liquid countercurrent hydrogenation method to carry out hydrocracking and isomerization reactions on the hydrotreating reactants obtained in step 2);

4) Fractionating the liquid-phase production oil obtained in step 3) to obtain high-quality diesel oil.

Further, in the step 2), the inferior raw material oil and the Fischer-Tropsch wax oil are mixed in a ratio of 1:3.5 to 2:1.

Further, in the step 2), the operating conditions of the hydrofining reaction are: the reaction temperature is 260-400°C, the reaction pressure is 2.0-15.0MPa, the liquid hourly volume space velocity is 0.4-3h ^-1 , the hydrogen The oil volume ratio is 100-1000.

Further, in the step 3), the operating conditions of the hydrocracking and isomerization reactions are as follows: the reaction temperature is 300-420°C, the reaction pressure is 2.0-15.0MPa, and the liquid hourly volume space velocity is 0.4-3h ^-1 , the volume ratio of hydrogen to oil is 100-1000.

Further, in the step 2), the operating conditions of the hydrofining reaction are: the reaction temperature is 320-380°C, the reaction pressure is 4.0-10MPa, the liquid hourly volume space velocity is 0.5-2.0h ^-1 , the hydrogen The oil volume ratio is 150-550.

Further, in the step 3), the operating conditions of the hydrocracking and isomerization reactions are as follows: the reaction temperature is 330-390°C, the reaction pressure is 4.0-10MPa, and the liquid hourly volume space velocity is 0.5-2.0h ^-1 , the volume ratio of hydrogen to oil is 150-550.

Further, in the step 1), the operating conditions of the hydrofining reaction are as follows: the reaction temperature is 260-400°C, the reaction pressure is 2.0-15.0MPa, and the liquid hourly volume space velocity is 1.5-7.0h ^-1 .

Further, in the step 1), the operating conditions of the hydrofining reaction are as follows: the reaction temperature is 320-380°C, the reaction pressure is 4.0-10MPa, and the liquid hourly volume space velocity is 2.0-5.0h ^-1 .

Further, in the step 2), the inferior raw material oil and the Fischer-Tropsch wax oil are mixed in a ratio of 1:2-1.7:1.

Further, the inferior raw material oil is secondary processed diesel oil.

Further, the secondary processed diesel oil is one or more of catalytic cracking diesel oil, coker diesel oil and coal tar diesel oil, and its aromatic hydrocarbon weight content is 25-75%.

Further, the aromatic hydrocarbon weight content of the secondary processed diesel oil is 30-60%.

Further, in the step 1) and step 2), the hydrofining catalyst includes a support and a hydrogenation active metal, the support is alumina or silicon-containing alumina, and the hydrogenation active metal is VIB group and/or Group VIII metals.

Further, based on the total weight of the hydrorefining catalyst, based on the hydrogenation active metal oxide, the weight content of the VIB group metal oxide is 10-30%, and the weight content of the VIII group metal oxide is 5-15%.

Further, in the step 3), the hydrocracking and isomerization catalyst is a hydroisomerization catalyst containing β-type molecular sieve, the carrier is amorphous silica-alumina, and the hydrogenation active metal is VIB group metal and and/or Group VIII metals.

Furthermore, the hydrocracking and isomerization catalyst includes a β-type molecular sieve, a carrier and a hydrogenation active metal, the carrier is amorphous silica-alumina, and the hydrogenation active metal is W and Ni, so that the hydrogenation The total weight of the hydrocracking and isomerization catalyst is based on the hydrogenation active metal _oxide , the weight content of WO3 is 10-35%, the weight content of NiO is 5-15%, and the weight content of β-type molecular sieve is 8-30%.

The equipment for producing high-quality diesel oil through combined hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil designed to realize the above method in the present invention includes a hydrogen mixing tank, a liquid-phase hydrogenation reactor, a gas-liquid countercurrent reactor, and a fractionator. Its features In that: the hydrogen mixing tank is provided with a Fischer-Tropsch diesel inlet, a circulating hydrogen inlet and a saturated hydrogen-dissolved diesel outlet, and the saturated hydrogen-dissolved diesel outlet is connected to the oil inlet of the liquid-phase hydrogenation reactor; the gas The liquid countercurrent reactor includes a hydrofinishing reaction zone at the top and a hydrocracking and isomerization reaction zone at the bottom. The top of the gas-liquid countercurrent reactor is provided with an oil inlet and a gas outlet. The gas-liquid countercurrent reactor There are hydrogen inlets and oil outlets at the bottom end, the oil outlet of the liquid-phase hydrogenation reactor is connected with the oil inlet of the gas-liquid countercurrent reactor, and the oil outlet of the gas-liquid countercurrent reactor is connected with the The oil inlet connection of the fractionator.

Further, it also includes a gas-liquid separator, the gas-liquid inlet of the gas-liquid separator is connected to the gas outlet of the gas-liquid countercurrent reactor, and the gas outlet of the gas-liquid separator is respectively connected to the hydrogen mixing tank The circulating hydrogen inlet is connected with the hydrogen inlet of the gas-liquid countercurrent reactor.

Furthermore, the tail oil outlet of the fractionator is connected with the oil inlet of the gas-liquid countercurrent reactor.

Compared with the prior art, the present invention has the following advantages:

First, the present invention aims at the deficiencies of the prior art and the respective characteristics of low-temperature Fischer-Tropsch synthetic oil and low-quality feedstock oil, and provides a combination of liquid-phase hydrogenation and vapor-liquid countercurrent hydrogenation for Fischer-Tropsch synthetic oil and The method of processing inferior diesel oil to produce high-quality diesel oil can obtain diesel oil with qualified density and high cetane number, which solves the problem of diesel component density obtained after low-temperature Fischer-Tropsch synthetic oil undergoes hydrotreating, hydrocracking and isomerization It is relatively low and difficult to meet the technical problem of vehicle diesel standards. The invention not only provides a reliable production method for Fischer-Tropsch synthetic oil to produce qualified diesel oil, but also provides a way out for inferior raw material oil.

Second, due to the high content of impurities such as sulfur, nitrogen, and aromatic hydrocarbons in secondary processed diesel oil such as catalytic cracking diesel oil, coking diesel oil, and coal tar diesel oil, the H produced by the reaction in the existing hydrogenation process ₂ S, NH ₃ and other gaseous impurities are competitively adsorbed on the active centers on the surface of the catalyst, which has a great inhibitory effect on the reaction processes such as hydrocracking and isomerization. The reaction temperature required for hydrocracking will be high, which will further It affects the service life of the catalyst, increases energy consumption and operating costs, while the present invention uses the gas-liquid countercurrent hydrogenation method to take away the gaseous impurities such as H ₂ S and NH ₃ generated by the reaction by using the hydrogen flowing upwards, thus avoiding the H ₂ Inhibition of S, NH ₃ and other gaseous impurities on hydrocracking and isomerization catalysts.

Third, the present invention combines the liquid-phase hydrogenation method with the vapor-liquid countercurrent hydrogenation method. The liquid-phase circulating hydrogenation process relies on the dissolved hydrogen carried into the reaction system when a large number of liquid-phase products are circulated to provide the required hydrogenation reaction. Hydrogen not only consumes less hydrogen, but also reduces equipment investment and operating costs, while the gas-liquid countercurrent hydrogenation process requires relatively little hydrogen oil, so the method of the present invention can greatly reduce the load of the circulating compressor, and has low energy consumption and process The process is simple.

Description of drawings

Figure 1 is a schematic diagram of the connection structure of equipment for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, so as to facilitate a clearer understanding of the present invention, but they do not limit the present invention.

The equipment for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil shown in Figure 1 includes a hydrogen mixing tank 1, a liquid phase hydrogenation reactor 2, a gas-liquid countercurrent reactor 3, and a fractionator 4. The hydrogen tank 1 is equipped with a Fischer-Tropsch diesel inlet 1-1, a circulating hydrogen inlet 1-2 and a saturated hydrogen-dissolving diesel outlet 1-3, and the saturated hydrogen-dissolving diesel outlet 1-3 is connected to the liquid-phase hydrogenation reactor 2 The oil inlet 2-1 is connected; the gas-liquid countercurrent reactor 3 includes a hydrofinishing reaction zone 3-1 at the top and a hydrocracking and isomerization reaction zone 3-2 at the bottom, and the gas-liquid countercurrent reaction The top of the device 3 has an oil inlet 3-3 and a gas outlet 3-4, and the bottom end of the gas-liquid countercurrent reactor 3 has a hydrogen inlet 3-5 and an oil outlet 3-6. The oil outlet 2-2 of the hydrogen reactor 2 is connected with the oil inlet 3-3 of the gas-liquid countercurrent reactor 3, and the oil outlet 3-6 of the gas-liquid countercurrent reactor 3 is connected with the fractionator 4 The oil inlet 4-1 is connected; the gas outlet 3-4 of the gas-liquid countercurrent reactor 3 is connected with a gas-liquid separator 5, and the gas outlet 3-4 of the gas-liquid countercurrent reactor 3 is connected to the gas outlet 3-4. The gas-liquid inlet 5-1 of the liquid separator 5 is connected, and the gas outlet 5-2 of the gas-liquid separator 5 is respectively connected with the circulating hydrogen inlet 1-2 of the hydrogen mixing tank 1 and the gas-liquid countercurrent reactor 3 The hydrogen inlet 3-5 is connected; the tail oil outlet 4-2 of the fractionator 4 is connected with the oil inlet 3-3 of the gas-liquid countercurrent reactor 3.

The working process of the above-mentioned low-temperature Fischer-Tropsch synthetic oil combined with low-quality feedstock oil to produce high-quality diesel is as follows: Fischer-Tropsch diesel and circulating hydrogen are respectively imported from Fischer-Tropsch diesel on the hydrogen mixing tank 1 1-1 and circulating hydrogen is imported 1- 2 enters the hydrogen mixing tank 1 for hydrogen mixing treatment, and enters the liquid phase hydrogenation reactor equipped with a hydrofinishing catalyst after saturated hydrogen dissolution. The oil outlet 2-2 of the liquid phase hydrogenation reactor 2 flows out, enters the gas-liquid countercurrent reactor 3 through the oil inlet 3-3 of the gas-liquid countercurrent reactor 3, and at the same time, the oil inlet from the gas-liquid countercurrent reactor 3 Port 3-3 introduces Fischer-Tropsch wax oil and low-quality raw material oil, Fischer-Tropsch wax oil, low-quality raw material oil and Fischer-Tropsch diesel oil after saturated hydrogen dissolution enter the hydrofinishing reaction zone 3-1 for hydrofinishing reaction, and then add The liquid phase effluent after the hydrogen refining reaction enters the hydrocracking and isomerization reaction zone 3-2 for hydrocracking and isomerization reaction, wherein hydrogen is introduced from the hydrogen inlet 3-5 at the bottom of the gas-liquid countercurrent reactor 3 , the liquid phase product after hydrocracking and isomerization reaction flows out from the oil outlet 3-6 of the gas-liquid countercurrent reactor 3, and enters the fractionator 4 through the oil inlet 4-1 of the fractionator 4 for fractionation to obtain high-quality Diesel oil, dry gas and tail oil, high-quality diesel oil, dry gas and tail oil respectively flow out from the diesel outlet 4-3, dry gas outlet 4-4 and tail oil outlet 4-2 of the fractionator 4, and the tail oil undergoes gas-liquid countercurrent reaction The oil inlet 3-3 at the top of the device 3 circulates back to the gas-liquid countercurrent reactor 3. In addition, the gas phase product produced after the hydrogenation reaction in the gas-liquid countercurrent reactor 3 is discharged from the gas outlet 3-4 at the top of the gas-liquid countercurrent reactor 3, and enters the gas-liquid separation through the gas-liquid inlet 5-1 of the gas-liquid separator 5 The hydrogen gas separated by the gas-liquid separator 5 enters the circulating hydrogen system to provide hydrogen for the hydrogen mixing tank 1 and the gas-liquid countercurrent reactor 3. Wherein, the hydrofinishing catalyst used in the hydrofinishing reaction zone 3-1 of the liquid phase hydrogenation reactor 2 and the gas-liquid countercurrent reactor 3 can be a conventional commercially available hydrofinishing catalyst, and the hydrofinishing catalyst is based on alumina Or silicon-containing alumina is used as the carrier, the hydrogenation active metal is VIB and/or Group VIII metal, the Group VIB metal is generally Mo and/or W, and the Group VIII metal is generally Co and/or Ni, based on the total weight of the catalyst Based on oxides, the content of metal oxides in Group VIB is 10-30%, and the content of metal oxides in Group VIII is 5-15%; The hydrorefining catalyst used in the stereomerization reaction zone 3-2 can also be a conventional commercially available hydrocracking and isomerization catalyst, the hydrocracking and isomerization catalyst is a hydroisomerization catalyst containing β-type molecular sieve, and the carrier It is amorphous silicon-alumina, and the hydrogenation active metal components are VIB group metal elements molybdenum and tungsten, VIII group metal elements cobalt and nickel, mostly using W-Ni metal combination, and the hydrocracking catalyst is based on the total weight of the catalyst , in terms of oxides, the weight content of active metal WO ₃ is 10-35%, the weight content of NiO is 5-15%, and the weight content of β-type molecular sieve is 8-30%.

Embodiment 1-4

Embodiments 1 to 4 all adopt low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil combined hydrogenation to produce high-quality diesel oil as shown in Fig. oil and inferior raw material oil mixture, the properties of the raw material oil used are shown in Table 1 below; the mixing ratio of Fischer-Tropsch wax oil and inferior raw material oil used in Examples 1 to 4 and the specific process conditions are shown in Table 2 below; the evaluation results of Examples 1 to 4 are shown in Table 3 below.

Comparative example 1

In comparative example 1, the raw material oil entering the gas-liquid countercurrent reactor is not mixed with low-quality raw material oil, and Fischer-Tropsch wax oil is fed separately, that is, the raw material oil is Fischer-Tropsch diesel oil and Fischer-Tropsch wax oil, and the properties of the raw material oil are shown in Table 1 below; The process conditions are shown in Table 2 below; the evaluation results are shown in Table 3 below.

Comparative example 2

Comparative example 2 and embodiment 2 adopt the same raw material, and control conversion rate is consistent, wherein, the raw material oil of comparative example 2 adopts Fischer-Tropsch diesel oil and Fischer-Tropsch wax oil and inferior raw material oil mixture, and the raw material oil property used sees the following table 1; In Comparative Example 2, the traditional gas-liquid parallel flow process was adopted, and the mixing ratio of Fischer-Tropsch wax oil and inferior raw material oil and the specific process conditions are shown in Table 2 below; the evaluation results are shown in Table 3 below.

The feedstock oils used in Examples 1 to 4, Comparative Example 1 and Comparative Example 2 include Fischer-Tropsch diesel oil, Fischer-Tropsch wax oil, catalytic cracking diesel oil and coked diesel oil. The relevant property parameters of these feedstock oils are shown in Table 1 below:

Table 1

The concrete processing conditions of embodiment 1～4, comparative example 1 and comparative example 2 are shown in the following table 2:

Table 2

Embodiment 1～4, comparative example 1 and the diesel oil performance evaluation result that comparative example 2 produces are shown in the following table 3:

table 3

It can be seen from the above table 3 that the method of the present invention can obtain low-condensation high-quality diesel oil with high cetane number, and the density of the diesel oil is greatly improved. In addition, Example 2 is compared with Comparative Example 2. As can be seen from Table 2 and Table 3, it can be seen from the comparison of Example 2 and Comparative Example 2 that when the same raw material is processed and the same conversion rate is controlled, using In Example 2 of the method of the present invention, the reaction temperature of the hydrocracking and isomerization catalyst is 20°C lower than that of Comparative Example 2, so it can be seen that the method of the present invention can effectively reduce operating costs and energy consumption. It can also be seen from Comparative Example 1 that when the raw material oil is only Fischer-Tropsch diesel and Fischer-Tropsch wax oil, the density of the diesel produced is low, only 0.7585g/cm ³ .

Claims (16)

1. A method for the joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil to produce high-quality diesel oil, characterized in that: comprise the following steps: 1) The Fischer-Tropsch diesel is subjected to hydrogen-mixing treatment, and after saturated hydrogen dissolution, the liquid-phase circulating hydrogenation method is used for hydrofining; 2) Mixing the hydrofining reactant obtained in step 1) with inferior raw material oil and Fischer-Tropsch wax oil to obtain a mixed oil, and then adopting a gas-liquid countercurrent hydrogenation method to carry out hydrofining on the mixed oil; The operating conditions of the hydrogen refining reaction are: reaction temperature 260-400°C, reaction pressure 2.0-15.0MPa, liquid hourly volume space velocity 0.4-3h ^-1 , hydrogen-oil volume ratio 100-1000; 3) Continue to use the gas-liquid countercurrent hydrogenation method to carry out hydrocracking and isomerization reactions on the hydrotreating reactants obtained in step 2); 4) fractionating the liquid-phase production oil obtained in step 3) to obtain high-quality diesel oil; The inferior raw material oil is secondary processed diesel oil; the secondary processed diesel oil is one or more of catalytic cracking diesel oil, coking diesel oil and coal tar diesel oil, and its aromatic hydrocarbon weight content is 25-75%. 2. the method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil to produce high-quality diesel oil according to claim 1, is characterized in that: in described step 2), described inferior feedstock oil and described Fischer-Tropsch wax oil Mix according to the mass ratio of 1:3.5～2:1. 3. the method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil to produce high-quality diesel oil according to claim 1, characterized in that: in the step 3), the operation of the hydrocracking and isomerization reaction The conditions are as follows: the reaction temperature is 300-420°C, the reaction pressure is 2.0-15.0 MPa, the liquid hourly volume space velocity is 0.4-3h ^-1 , and the hydrogen-oil volume ratio is 100-1000. 4. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil to produce high-quality diesel oil according to any one of claims 1 to 3, characterized in that: in the step 2), the hydrorefining reaction The operating conditions are as follows: the reaction temperature is 320-380°C, the reaction pressure is 4.0-10MPa, the liquid hourly volume space velocity is 0.5-2.0h ^-1 , and the hydrogen-oil volume ratio is 150-550. 5. The method for producing high-quality diesel oil through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil according to any one of claims 1 to 3, characterized in that: in the step 3), the hydrocracking and The operating conditions of the isomerization reaction are as follows: the reaction temperature is 330-390°C, the reaction pressure is 4.0-10MPa, the liquid hourly volume space velocity is 0.5-2.0h ^-1 , and the hydrogen-to-oil volume ratio is 150-550. 6. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil to produce high-quality diesel oil according to any one of claims 1 to 3, characterized in that: in the step 1), the hydrofining reaction The operating conditions are as follows: the reaction temperature is 260-400°C, the reaction pressure is 2.0-15.0MPa, and the liquid hourly volume space velocity is 1.5-7.0h ^-1 . 7. The method for producing high-quality diesel oil through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil according to claim 6, characterized in that: in the step 1), the operating conditions of the hydrofining reaction are: The temperature is 320-380°C, the reaction pressure is 4.0-10MPa, and the liquid hourly volume space velocity is 2.0-5.0h ^-1 . 8. The method for producing high-quality diesel oil through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior feedstock oil according to claim 1, characterized in that: in the step 2), the inferior feedstock oil and the Fischer-Tropsch wax oil Mix according to the mass ratio of 1:2-1.7:1. 9. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil according to claim 1, characterized in that: the weight content of aromatics in the secondary processed diesel oil is 30-60%. 10. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil to produce high-quality diesel oil according to claim 1, characterized in that: in the step 1) and step 2), the hydrorefining catalyst includes a carrier and a hydrogenation Hydrogen active metal, the carrier is alumina or silicon-containing alumina, and the hydrogenation active metal is VIB group and/or VIII group metal. 11. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality feedstock oil to produce high-quality diesel oil according to claim 10, characterized in that: based on the total weight of the hydrorefining catalyst, the hydrogenation active metal oxide In total, the weight content of the VIB group metal oxide is 10-30%, and the weight content of the VIII group metal oxide is 5-15%. 12. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil to produce high-quality diesel oil according to claim 1, characterized in that: in the step 3), the hydrocracking and isomerization catalyst contains β-type The hydrogenation isomerization catalyst of molecular sieve, its carrier is amorphous silicon aluminum, and its hydrogenation active metal is VIB group metal and/or VIII group metal. 13. The method for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil to produce high-quality diesel oil according to claim 12, characterized in that: the hydrocracking and isomerization catalyst includes β-type molecular sieve, carrier and hydrogenation Active metal, the carrier is amorphous silicon aluminum, the hydrogenation active metal is W and Ni, based on the total weight of the hydrocracking and isomerization catalyst, in terms of hydrogenation active metal oxide, WO The weight content of ₃ is 10-35%, the weight content of NiO is 5-15%, and the weight content of β-type molecular sieve is 8-30%. 14. An equipment for the joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil to produce high-quality diesel oil designed to realize the method described in claim 1, comprising a hydrogen mixing tank (1), a liquid phase hydrogenation reactor (2) , gas-liquid countercurrent reactor (3), fractionator (4), it is characterized in that: Fischer-Tropsch diesel inlet (1-1), circulating hydrogen inlet (1-2) and The saturated hydrogen-dissolved diesel oil outlet (1-3), the saturated hydrogen-dissolved diesel oil outlet (1-3) is connected with the oil inlet (2-1) of the liquid phase hydrogenation reactor (2); the gas-liquid The countercurrent reactor (3) includes a hydrofinishing reaction zone (3-1) at the top and a hydrocracking and isomerization reaction zone (3-2) at the bottom, and the top of the gas-liquid countercurrent reactor (3) is open There is an oil inlet (3-3) and a gas outlet (3-4), and the bottom end of the gas-liquid countercurrent reactor (3) has a hydrogen inlet (3-5) and an oil outlet (3-6), The oil outlet (2-2) of the liquid-phase hydrogenation reactor (2) is connected with the oil inlet (3-3) of the gas-liquid countercurrent reactor (3), and the gas-liquid countercurrent reactor ( 3) the oil outlet (3-6) is connected with the oil inlet (4-1) of the fractionator (4). 15. The equipment for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil according to claim 14, characterized in that: it also includes a gas-liquid separator (5), and the gas-liquid separator (5 ) of the gas-liquid inlet (5-1) is connected with the gas outlet (3-4) of the gas-liquid countercurrent reactor (3), and the gas outlet (5-2) of the gas-liquid separator (5) is connected with The circulating hydrogen inlet (1-2) of the hydrogen mixing tank (1) is connected with the hydrogen gas inlet (3-5) of the gas-liquid countercurrent reactor (3). 16. The equipment for joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and low-quality raw material oil to produce high-quality diesel oil according to claim 14, characterized in that: the tail oil outlet (4-2) of the fractionator (4) is connected to the The oil inlet (3-3) of the gas-liquid countercurrent reactor (3) is connected.