Petroleum-based rocket kerosene and preparation method thereof

Abstract

The invention discloses petroleum-based rocket kerosene and a preparation method thereof. The petroleum-based rocket kerosene comprises cycloalkane, paraffin and / or aromatic hydrocarbon; the total weight of the petroleum-based rocket kerosene is 100%, the content of the cycloalkane is 70-95%, the content of the paraffin is 0-30%, the content of the aromatic hydrocarbon is 0-5%, and the carbon number of the cycloalkane, the carbon number of the paraffin and the carbon number of the aromatic hydrocarbon are distributed between C7 and C16. According to the petroleum-based rocket kerosene, the catalytically cracked diesel oil generated in the petroleum refining process serves as the raw material, the rocket kerosene meeting the key index requirements of GJB 9629 can be prepared through the technological process of fractionation, hydrogenation and re-fractionation, the raw material source is greatly expanded, and the petroleum-based rocket kerosene has high economic value and application prospects.

Description

Technical Field

[0001] The invention belongs to the field of fuel oil, and in particular, relates to a petroleum-based rocket kerosene derived from catalytic cracking diesel and a preparation method thereof. Background Art

[0002] As a mature and widely used main propulsion fuel for launch vehicles at room temperature, rocket kerosene is favored by domestic and foreign aerospace companies. Compared with other rocket fuels such as liquid hydrogen, hydrazine fuel, and liquid methane, rocket kerosene has the following advantages: (1) High safety. It can be used as a propellant at room temperature, which makes it more convenient and safer; (2) High economy. Its low price can significantly reduce the launch cost of rockets; (3) High environmental protection. Kerosene itself has low toxicity and basically produces water and carbon dioxide after combustion; (4) High feasibility. The development of liquid oxygen-kerosene engines is relatively easy. Therefore, rocket kerosene has a wider application market.

[0003] As a major aerospace power, my country's demand for rocket kerosene will continue to rise. In addition, with the rapid development of my country's commercial aerospace, domestic commercial aerospace companies have put forward new requirements for the supply of rocket kerosene, requiring it to be more stable, convenient and flexible. Therefore, the market demand for aerospace kerosene will enter a period of rapid growth. These factors make the development of new rocket kerosene crucial.

[0004] Patent CN 109576012 B discloses a self-igniting rocket fuel and natural propellant, which is a multi-substituted azine compound or rocket kerosene with such additives. This type of self-igniting rocket fuel has high energy density, high nitrogen content, and certain toxicity. It is mainly used as a self-igniting fuel and does not involve the development of basic rocket kerosene components. Patent CN 104789260 B discloses a method for producing rocket kerosene from coal tar. The produced rocket kerosene has a high calorific value and specific gravity, and a high content of cis-decalin. However, this method mainly uses coal tar as a raw material, and there are not many coal tar production and coal tar production enterprises in my country. There are still problems of insufficient raw material supply and inconvenience. In addition, the density, distillation range and other indicators of the rocket kerosene prepared in the patent do not meet the requirements of GJB 9629-2019 and cannot be used directly. The catalytic cracking diesel produced by major refineries during the petroleum refining process provides a new approach and idea for the preparation of rocket kerosene due to its high aromatic content, readily available and cheap raw materials, and mature hydrogenation conversion technology. Summary of the invention

[0005] In view of the problem that the demand for existing rocket kerosene is rapidly increasing but the production raw materials are single, the present invention provides a petroleum-based rocket kerosene derived from catalytic cracking diesel, which can significantly expand the raw material source of rocket kerosene, and can fully meet the requirements of GJB 9629 key indicators by limiting its chemical composition, and the freezing point is lower than -70°C, the low-temperature performance is excellent, and it has practical application prospects.

[0006] The present invention provides a petroleum-based rocket kerosene, comprising cycloalkanes, chain alkanes and / or aromatic hydrocarbons; based on the total weight of the petroleum-based rocket kerosene being 100%, the content of the cycloalkanes is 70-95%, the content of the chain alkanes is 0-30%, the content of the aromatic hydrocarbons is 0-5%, and the carbon numbers of the cycloalkanes, chain alkanes and aromatic hydrocarbon molecules are distributed between C7 and C16.

[0007] According to one embodiment of the present invention, the cycloalkane content is 80-90%, and the tricycloalkane content is less than 2%; the paraffin content is 10-20%; the aromatic content is less than 2%, and the tricycloaromatic content is less than 0.5%.

[0008] According to another embodiment of the present invention, the cycloalkanes, the chain alkanes and the aromatic hydrocarbons with carbon numbers distributed between C10 and C14 account for more than 90% of the total weight of the petroleum-based rocket kerosene, preferably more than 95%; the cycloalkanes, the chain alkanes and the aromatic hydrocarbons with carbon numbers distributed between C11 and C13 account for more than 75% of the total weight of the petroleum-based rocket kerosene, preferably more than 80%; more preferably more than 85%.

[0009] According to another embodiment of the present invention, an antioxidant is further included, and the antioxidant is added in an amount of 20-50 mg / L.

[0010] According to another embodiment of the present invention, the antioxidant is added in an amount of 20-30 mg / L.

[0011] According to another embodiment of the present invention, the antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, tert-butylhydroquinone, and 2,6-di-tert-butylphenol.

[0012] The present invention also provides a method for preparing the above-mentioned petroleum-based rocket kerosene, comprising: S1, using catalytic cracking diesel as a raw material, and removing components above 250° C. by distillation to obtain fraction A; S2, subjecting the fraction A to a hydrogenation reaction to obtain an intermediate product B; and S3, subjecting the intermediate product B to a distillation to remove light components and heavy components to obtain the petroleum-based rocket kerosene.

[0013] According to one embodiment of the present invention, the weight proportion of monocyclic and bicyclic aromatic hydrocarbons in the fraction A reaches 70-85%; the content of cycloalkanes in the intermediate product B is 65-90%.

[0014] According to another embodiment of the present invention, the fractionation temperature of the light component is below 190°C, and the fractionation temperature of the heavy component is above 245°C.

[0015] According to another embodiment of the present invention, the catalyst for the hydrogenation reaction includes one or more of Group VIII metals, and the catalyst carrier is selected from one or more of alumina, silicon oxide, and zeolite molecular sieves; the temperature of the hydrogenation reaction is 250-450°C, the reaction hydrogen pressure is 4-16MPa, and the liquid hourly volume space velocity is 0.1-5h -1 , hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 .

[0016] This application creatively proposes a petroleum-based rocket kerosene derived from catalytic cracking diesel, which can fully meet the key index requirements in GJB 9629 "Specifications for Kerosene for Liquid Rocket Engines", where catalytic cracking diesel refers to catalytic cracking diesel produced in the process of petroleum refining, or a mixture of catalytic cracking diesel and catalytic cracking heavy cycle oil. The present invention broadens the source of raw materials for rocket fuel, provides support for the growing demand for rocket kerosene, and ensures the safety of my country's aerospace oil. In addition, the raw material source is wide, the cost is low, and the conversion technology is mature, with industrial application prospects and significant economic and social benefits. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with specific implementation modes.

[0018] The petroleum-based rocket kerosene of the present invention comprises cycloalkanes, chain alkanes and / or aromatic hydrocarbons; based on the total weight of the petroleum-based rocket kerosene being 100%, the cycloalkanes content is 70-95%, the chain alkanes content is 0-30%, the aromatic hydrocarbon content is 0-5%, and the carbon numbers of the cycloalkanes, chain alkanes and aromatic hydrocarbon molecules are distributed between C7 and C16.

[0019] Preferably, the cycloalkane content is 80-90%, wherein the tricycloalkane content is less than 2%; the paraffin content is 10-20%; the aromatic content is less than 2%, wherein the tricyclic aromatic content is less than 0.5%.

[0020] In an optional embodiment, cycloalkanes, paraffins and aromatics with carbon numbers between C10 and C14 account for more than 90% of the total weight of petroleum-based rocket kerosene, preferably more than 95%. Cycloalkanes, paraffins and aromatics with carbon numbers between C11 and C13 account for more than 75% of the total weight of petroleum-based rocket kerosene, preferably more than 80%; more preferably more than 85%.

[0021] Petroleum-based rocket kerosene may also contain an appropriate amount of antioxidant. The antioxidant is added in an amount of 20-50 mg / L, preferably 20-30 mg / L. The antioxidant may be selected from any conventional antioxidant in the art, preferably one or more of 2,6-di-tert-butyl-p-cresol, tert-butylhydroquinone, and 2,6-di-tert-butylphenol.

[0022] The petroleum-based rocket kerosene of the present invention is prepared by using catalytic cracking diesel as raw material through a process flow of fractionation-hydrogenation-re-fractionation. Specifically, the method for preparing the petroleum-based rocket kerosene of the present invention includes: S1, using catalytic cracking diesel as raw material, removing components above 250°C through fractionation to obtain fraction A; S2, hydrogenating fraction A to obtain intermediate product B; and S3, fractionating intermediate product B to remove light components and heavy components to obtain petroleum-based rocket kerosene. The fractionation in this patent can be any appropriate method, such as atmospheric pressure fractionation, rectification, etc.

[0023] In step S1, the fractionation operation is to fractionate the raw material to obtain a fraction A rich in monocyclic and bicyclic aromatic hydrocarbons, wherein the weight proportion of monocyclic and bicyclic aromatic hydrocarbons reaches 70-85%. In step S2, the hydrogenation operation is to saturate most of the unsaturated hydrocarbons to obtain a hydrogenated intermediate product B. The cycloalkane content in the intermediate product B is 65-90%. In step S3, the re-fractionation operation of the intermediate product B is to fractionate the hydrogenated product to obtain a component rich in monocyclic and bicyclic alkanes, wherein the weight proportion of monocyclic and bicyclic alkanes is 70-95%.

[0024] In step S2, the fractionation temperature of the light component is below 190° C., and the fractionation temperature of the heavy component is above 245° C. The above fractionation temperatures of the light component and the heavy component are only examples, and the present invention is not limited to the fractionation temperatures. Those skilled in the art can select appropriate fractionation temperatures of the light component and the heavy component according to the final product.

[0025] The fractionation process of step S1 and the re-fractionation process of the hydrogenated product in step S3 can be completed by common methods such as distillation and rectification. The hydrogenation process can be completed using a common hydrogenation catalyst. For example, the hydrogenation active metal includes at least one or more of the Group VIII metals, and the catalyst carrier is selected from alumina, silicon oxide, zeolite molecular sieve, etc. The hydrogenation reaction temperature is 250-450°C, the reaction hydrogen pressure is 4-16MPa, and the liquid hourly volume space velocity is 0.1-5h -1 , hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 .

[0026] The following examples further illustrate the specific implementation of the present invention. The catalytic cracking diesel oil is from Yanshan Petrochemical. The hydrogenation catalyst used is 5Ni-25Mo / Al2O3 with a specific surface area of ​​275m2 / g, the average pore size is 12.5nm, and the preparation process is as follows: according to the loading amount, a certain amount of MoO3, basic nickel carbonate, ethylene glycol and citric acid are added into water respectively, and completely dissolved under heating and stirring to obtain an impregnation solution containing active metals, and the impregnation solution is evenly mixed with the carrier Al2O3, and then allowed to stand at room temperature for 8h, and then dried at 120℃ for 5h, and calcined at 500℃ in air atmosphere for 3h to prepare an oxidized catalyst, and then reduced at 550℃ in hydrogen atmosphere for 3h before use.

[0027] Embodiment 1, comparative example 1:

[0028] The properties of catalytic cracking diesel A and A1 after raw material fractionation are listed in Table 1. The fractionation treatment can be completed by conventional distillation, rectification and other operation means, and its goal is to remove the components above 250° C. in raw material A.

[0029] It can be seen from the table that regardless of whether it has been distilled or not, the aromatic content in the catalytic cracking diesel feedstock for producing rocket fuel is above 70%. After distillation, the sulfur content, nitrogen content, dicyclic aromatic content, and tricyclic aromatic content in feedstock A can be significantly reduced, while the monocyclic aromatic content is significantly increased, which is beneficial to reducing the sulfur content, nitrogen content and tricyclic alkane content in the generated rocket fuel, and is beneficial to inhibiting the formation of carbon deposits and increasing the life of the rocket engine.

[0030] Table 1

[0031]

[0032] Embodiment 2, comparative example 2:

[0033] The above raw materials were hydrogenated in a fixed bed at a reaction temperature of 320°C, a reaction pressure of 10 MPa, and a liquid hourly volume space velocity of 1.0 h -1 , the volume ratio of hydrogen to oil is 800.

[0034] After hydrogenation reaction, rocket fuel initial products B and B1 were prepared using raw materials A and raw material A1 respectively. The key properties of B and B1 were analyzed, and the results are shown in Table 2.

[0035] Table 2

[0036]

[0037] It can be seen that after hydrogenation, a large amount of aromatics are converted into cycloalkanes, with cycloalkanes accounting for 70-90%. Compared with B obtained without raw material fractionation, B1 is lighter overall after fractionation, and the total aromatic content is lower, which can meet the requirement of no more than 5%. However, it can also be seen that the two initial products still cannot meet the requirements of GJB 9629 in terms of freezing point, flash point, distillation range and other indicators. Therefore, rocket fuel cannot be directly produced by hydrotreating catalytic cracking diesel raw material A alone, and qualified rocket fuel cannot be directly obtained by fractionating and cutting raw material A and then hydrotreating it.

[0038] Embodiment 3, comparative example 3:

[0039] Therefore, the obtained primary products B and B1 were fractionated to obtain finished products C and C1 respectively. The fractionation treatment was completed by atmospheric distillation. The goal of the fractionation treatment was to cut off the components below 190°C and above 245°C of the primary products. The key properties of C and C1 were analyzed, and the results are shown in Table 3.

[0040] Table 3

[0041]

[0042]

[0043] It can be seen from the above table that after further distillation of the primary product, the total cycloalkane content increased and the total aromatic content decreased, which is beneficial to reduce the carbon deposits produced by incomplete combustion of aromatics during fuel combustion, which has a very important impact on the performance and life of the engine.

[0044] At the same time, it can be seen that the finished product C obtained after product fractionation still cannot meet the requirements of GJB 9629 in terms of flash point, distillation range and density. The hydrocarbon composition of the finished product C1 obtained after product fractionation is shown in Table 3, and the carbon number distribution analysis shows that the carbon number is between C7 and C16 (as shown in Table 4). Its key indicators can meet the requirements of GJB9629, and the freezing point is lower than -70°C, and the low-temperature performance is excellent. Further analysis of the remaining properties according to the requirements of GJB 9629 shows that the finished product C1 has an appearance of a colorless, transparent, uniform liquid, and a kinematic viscosity of 2.6 mm at 20°C. 2 / s, kinematic viscosity at -40°C is 11.8mm 2 / s, iodine value is 0.05gI / 100g, actual colloid is <1mg / 100mL, mercaptan sulfur is <0.0003%, copper corrosion is level 1a, acidity is 0.1mg KOH / 100mL, water content is 20mg / kg, solid particle pollutant content is 0.2mg / L, all of which can meet the index requirements of GJB 9629.

[0045] Table 4

[0046]

[0047]

[0048] Then, adding antioxidant 2,6-di-tert-butyl-p-cresol at a concentration of 20 mg / L can obtain qualified rocket fuel products. Therefore, qualified rocket fuel products can be prepared by the process of raw material fractionation-hydrogenation-product fractionation of catalytic cracking diesel, which provides a richer, more flexible and cheaper raw material source and corresponding production plan for rocket fuel.

[0049] Example 4

[0050] The same reaction raw materials and reaction conditions as in Example 2 were used, but the reaction temperature was adjusted to 400°C. The reacted material was further subjected to the product fractionation treatment described in Example 3 to obtain the D1 product, and the key properties were analyzed. The results are shown in Table 5.

[0051] Example 5

[0052] The same reaction materials and reaction conditions as in Example 2 were used, but the reaction temperature was adjusted to 300°C. The reacted material was further subjected to the product fractionation treatment described in Example 3 to obtain the E1 product, and the key properties were analyzed. The results are shown in Table 5.

[0053] Example 6

[0054] The same reaction materials and reaction conditions as in Example 2 were used, but the reaction space velocity was adjusted to a liquid volume space velocity of 4.0 h -1 The reacted material was further subjected to the product fractionation treatment described in Example 3 to obtain the F1 product, and the key properties were analyzed. The results are shown in Table 5.

[0055] Example 7

[0056] The same reaction raw materials and reaction conditions as in Example 2 were used, but the reaction hydrogen pressure was adjusted to 15 MPa. The reacted material was further subjected to the product fractionation treatment described in Example 3 to obtain the H1 product, and the key properties were analyzed. The results are shown in Table 5.

[0057] Table 5

[0058]

[0059]

[0060] The carbon number distribution analysis of the four rocket kerosene products in Table 5 showed that the carbon number range was between C7 and C16, and the other indicators could meet the requirements of GJB 9629.

[0061] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A petroleum-based rocket kerosene, characterized in that: It includes cycloalkanes, chain alkanes and / or aromatic hydrocarbons; based on the total weight of petroleum-based rocket kerosene as 100%, the cycloalkanes content is 70-95%, the chain alkanes content is 0-30%, the aromatic hydrocarbon content is 0-5%, and the carbon numbers of the cycloalkanes, chain alkanes and aromatic hydrocarbon molecules are distributed between C7 and C16.

2. The petroleum-based rocket kerosene according to claim 1, characterized in that The cycloalkane content is 80-90%, and the tricycloalkane content is less than 2%; the chain alkane content is 10-20%; the aromatic content is less than 2%, and the tricycloaromatic content is less than 0.5%.

3. The petroleum-based rocket kerosene according to claim 1, characterized in that The cycloalkanes, chain alkanes and aromatic hydrocarbons with carbon numbers distributed between C10 and C14 account for more than 90% of the total weight of the petroleum-based rocket kerosene, preferably more than 95%; the cycloalkanes, chain alkanes and aromatic hydrocarbons with carbon numbers distributed between C11 and C13 account for more than 75% of the total weight of the petroleum-based rocket kerosene, preferably more than 80%; more preferably more than 85%.

4. The petroleum-based rocket kerosene according to claim 1, characterized in that The invention also contains an antioxidant, wherein the antioxidant is added in an amount of 20-50 mg / L.

5. The petroleum-based rocket kerosene according to claim 4, characterized in that The antioxidant is added in an amount of 20-30 mg / L.

6. The petroleum-based rocket kerosene according to claim 4, characterized in that The antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, tert-butylhydroquinone and 2,6-di-tert-butylphenol.

7. A method for preparing petroleum-based rocket kerosene according to any one of claims 1 to 6, characterized in that: include: S1, using catalytic cracking diesel as raw material, fraction A is obtained by fractionation to remove components above 250°C; S2, performing a hydrogenation reaction on the fraction A to obtain an intermediate product B; and S3, fractionating the intermediate product B to remove light components and heavy components to obtain the petroleum-based rocket kerosene.

8. The preparation method according to claim 7, characterized in that: The weight proportion of monocyclic and bicyclic aromatic hydrocarbons in the fraction A reaches 70-85%; the content of cycloalkanes in the intermediate product B is 65-90%.

9. The preparation method according to claim 7, characterized in that: The fractionation temperature of the light component is below 190°C, and the fractionation temperature of the heavy component is above 245°C.

10. The preparation method according to claim 7, characterized in that: The catalyst for the hydrogenation reaction includes one or more of Group VIII metals, and the catalyst carrier is selected from one or more of alumina, silicon oxide, and zeolite molecular sieves; the temperature of the hydrogenation reaction is 250-450°C, the reaction hydrogen pressure is 4-16MPa, and the liquid hourly volume space velocity is 0.1-5h -1 , hydrogen to oil volume ratio is 100-1500Nm 3 / m 3 .

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