Method for producing biological aviation kerosene from high-acid-value oil

Abstract

The invention discloses a method for producing biological aviation kerosene from high-acid-value oil, which comprises the following steps: mixing the high-acid-value oil without mechanical impurities with a deacidification pretreatment catalyst to obtain a mixture, and adding the mixture into a slurry bed reactor for deacidification pretreatment to obtain effluent; s2, performing solid-liquid separation on the effluent obtained in the step S1 to obtain a liquid-phase product, and performing hydrotreatment on the liquid-phase product sequentially through a fixed bed hydrodeoxygenation reactor, a fixed bed hydrocracking reactor and a fixed bed hydroisomerization reactor which are connected in series to obtain a hydrogenated product; and carrying out gas-liquid separation on the hydrogenation product to obtain a liquid product, and fractionating the liquid product to obtain a naphtha fraction, a biological aviation kerosene fraction and a biodiesel fraction. According to the method, the high-acid-value oil can be converted into the biological aviation kerosene in a high-yield manner.

Description

Technical Field

[0001] The invention relates to the field of producing bio-jet fuel from oil and fat, and in particular to a method for producing bio-jet fuel from oil and fat with high acid value. Background Art

[0002] As the supply of traditional fossil energy becomes increasingly tight and the pressure to reduce carbon dioxide emissions continues to increase, the development of renewable and clean alternative energy has become a common understanding around the world. Bioenergy has attracted much attention in recent years due to its renewable and green nature and is seen as one of the ideal ways to solve the global energy crisis. With the increasing demand for biofuels (including biojet fuel and biodiesel), the technology for preparing biojet fuel from renewable raw materials has attracted more and more attention.

[0003] Renewable raw materials are rich in variety and are not limited to the following: such as vegetable oils (soybean oil, rapeseed oil, palm oil, jatropha oil, jatropha oil, etc.), animal fats (lard, tallow, fish oil, etc.), acidified oils and various fatty acids, etc. At present, the most widely studied is the use of vegetable oils and / or animal fats to prepare bio-jet fuel components through hydrodeoxygenation, hydrocracking, and isomerization and decondensation processes.

[0004] US2009 / 0158637A1 discloses a method for preparing jet fuel from renewable raw materials. This method firstly hydrodeoxygenates vegetable oil and / or animal fat to obtain normal alkanes with carbon atoms of 8-24, then selectively cracks and isomerizes them, and finally obtains jet fuel that meets the requirements through fractionation. However, this method has the problem that the jet fuel yield is relatively low, and at the same time, some olefins will be generated during the cracking and isomerization process, which will have an adverse effect on the color of the jet fuel.

[0005] The invention patent application with patent number CN103059900A discloses a method for preparing jet fuel. The method comprises: under hydrodeoxygenation conditions, vegetable oil and / or animal fat, hydrogen and hydrodeoxygenation catalyst are contacted to obtain C8-C24 normal alkanes; under hydroisomerization conditions, C8-C24 normal alkanes, hydrogen and hydroisomerization catalyst are contacted, wherein the hydroisomerization catalyst contains a carrier and a metal active component, the carrier contains silicon phosphorus aluminum molecular sieve, and the metal active component contains one or more metal elements of Group VIII; under hydrorefining conditions, the product after contact in step 2, hydrogen and hydrorefining catalyst are contacted and fractionated to obtain jet fuel. The method can meet the standards of existing No. 3 jet fuel.

[0006] Although the above methods can all produce bio-jet fuel that meets the standards, these processes have high requirements for the quality of raw materials, and often use animal and plant oils with good quality, low impurity content and low acidity as raw materials. For some high-acid-value, low-quality oil raw materials, such as acidified palm oil and waste cooking oil, they often contain high free fatty acids. These fatty acids are prone to dissociation under high-temperature reactions to produce fatty acid radicals, and combine with the metal oxide carrier of the catalyst to form fatty acid salts, which cause acid corrosion and cause the structure of the catalyst to collapse and become inactive. In fact, palmitic acid oil, waste cooking oil, rancid oil, etc. with high acidity are secondary oils and fats, and their carbon emission reduction is higher than that of high-quality primary vegetable oils, making them more suitable as bio-jet fuel.

[0007] Therefore, developing a bio-jet fuel preparation technology suitable for high acid values ​​is beneficial to improving the carbon emission reduction of bio-jet fuel. At the same time, it can also expand the raw material sources of bio-jet fuel and has important application value. Summary of the invention

[0008] The invention provides a method for producing bio-jet fuel from high-acid value oil and fat. The method can convert the high-acid value oil and fat into bio-jet fuel with a high yield.

[0009] The present invention provides a method for producing bio-jet fuel from high acid value oil, comprising:

[0010] S1, mixing a high-acid value oil from which mechanical impurities have been removed and a deacidification pretreatment catalyst to obtain a mixture, and adding the mixture to a slurry bed reactor for deacidification pretreatment to obtain an effluent;

[0011] S2, performing solid-liquid separation on the effluent obtained in step S1 to obtain a liquid product, and sequentially passing the liquid product through a fixed bed hydrodeoxygenation reactor, a fixed bed hydrocracking reactor and a fixed bed hydroisomerization reactor connected in series to perform hydrogenation treatment to obtain a hydrogenated product;

[0012] S3. Separate the hydrogenation product into gas and liquid to obtain a liquid product, and fractionate the liquid product to obtain a bio-jet fuel fraction.

[0013] The present invention performs deacidification pretreatment by using a deacidification treatment catalyst before hydrogenation of high acid value oils and fats, so that the acid value of the high acid value oils and fats is greatly reduced, and the damage of the catalyst in the subsequent hydrogenation process by the higher fatty acids is avoided, so that a bio-jet fuel fraction with a higher yield can be obtained.

[0014] Preferably, the deacidification pretreatment catalyst is a Group IIA or Group IV metal oxide or hydroxide, the Group IIA element is Be, Mg, Sr or Ba, and the Group IV metal is Ti or Zr.

[0015] The present invention uses Group IIA or Group IV metal oxides or hydroxides as deacidification pretreatment catalysts to form alkaline substances on a slurry bed reactor, thereby converting free fatty acids in high-acid oils and fats in the slurry bed into neutral fatty ketones through decarboxylation and dehydration, thereby preventing the free fatty acids from corroding and damaging subsequent hydrogenation catalysts.

[0016] Further preferably, the deacidification pretreatment catalyst is MgO or ZrO.

[0017] The MgO and ZrO provided by the present invention 2 The abundant Lewis base sites on the surface promote the removal of α-H of fatty acids, thereby accelerating the decarboxylation and dehydration of free fatty acids in high acid value oils and fats to produce fatty ketones.

[0018] Further preferably, the deacidification pretreatment catalyst is MgO.

[0019] MgO can induce free fatty acids to form a bidentate adsorption configuration on the catalyst surface, which is beneficial to the activation of fatty acid α-H by the Lewis base sites on the catalyst surface, greatly promoting the ketolysis reaction of free fatty acids through decarboxylation and dehydration.

[0020] Preferably, the size of the deacidification pretreatment catalyst is 0.005-600 μm. The appropriate size can make the deacidification catalyst have a higher specific surface area, thus having better catalytic performance, and avoid being too small, which makes solid-liquid separation difficult.

[0021] Further preferably, the size of the deacidification pretreatment catalyst is 0.01-0.05 μm. The present invention further limits the catalyst size so that the specific surface area of ​​the catalyst is larger, the deacidification performance is better, and it is more conducive to solid-liquid separation.

[0022] Preferably, the method for preparing the deacidification pretreatment catalyst comprises:

[0023] Adding a precipitant to a soluble salt solution of Be, Mg, Sr, Ba, Ti or Zr metal, and drying at 60 to 120° C. for 0.5 to 12 hours to obtain a metal hydroxide;

[0024] Alternatively, the metal hydroxide is calcined at 350-750° C. for 5-12 hours to obtain the metal oxide, and the calcination atmosphere is an inert atmosphere of nitrogen or argon.

[0025] Further preferably, the soluble metal salts of Be, Mg, Sr and Ba are nitrates or hydrochlorides, and the soluble metal salts of Ti and Zr include nitrates, hydrochlorides or sulfates.

[0026] Further preferably, the precipitant includes one or more combinations of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, and ammonia water.

[0027] Preferably, the amount of the deacidification pretreatment catalyst added is 0.1-10% of the weight of the high acid value oil. By adding an appropriate amount of deacidification pretreatment catalyst, the fatty acids in the high acid value oil can be better removed, while also avoiding excessive deacidification pretreatment catalyst, which makes solid-liquid separation more difficult and increases the cost.

[0028] Preferably, the high acid value oil is one or more of acidified oil, waste cooking oil, acidified palm oil, rancid vegetable oil, and rancid animal oil.

[0029] Preferably, the fatty acid value of the high acid value oil is in the range of 80 to 200 mg KOH / g.

[0030] Preferably, the reaction conditions of the slurry bed reactor are: nitrogen partial pressure of 0.2-5 MPa, reaction temperature of 280-400°C, liquid hourly volume space velocity of 0.2-3.5 h -1 , the temperature difference of the axial temperature of the slurry bed reactor does not exceed 10°C;

[0031] The reaction conditions of the fixed bed hydrodeoxygenation reactor are: hydrogen partial pressure 4-10 MPa, reaction temperature 280-390°C, liquid hourly volume space velocity 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the fixed bed hydrodeoxygenation reactor is 200 to 1200;

[0032] The reaction conditions of the fixed bed hydrocracking reactor are: hydrogen partial pressure 5-10 MPa, reaction temperature 300-390°C, liquid hourly volume space velocity 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the reactor is 200 to 1200;

[0033] The reaction conditions of the fixed bed hydroisomerization reactor are: hydrogen partial pressure 4-10 MPa, reaction temperature 250-350° C., liquid hourly volume space velocity 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the reactor is 200 to 1200.

[0034] The present invention adopts a deoxygenation reactor, a hydrodeoxygenation reactor and a hydroisomerization reactor connected in series to achieve deep treatment of high acid value oils and fats, thereby obtaining high-quality bio-jet fuel components.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention adopts a slurry bed deacidification pretreatment process, introduces a deacidification treatment process before a hydrogenation treatment section, and converts free fatty acids in high-acid value oils and fats into neutral fatty ketones in the form of decarboxylation and dehydration. After the deacidification pretreatment, the acid value of the high-acid value oils and fats is reduced from 80 to 200 mg KOH / g to less than 1 mg KOH / g, thereby avoiding corrosion and damage of subsequent hydrogenation catalysts by free fatty acids, significantly protecting hydrogenation catalysts, extending the operation cycle of oil and fat hydrogenation treatment equipment, and improving the yield of bio-jet fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A process flow chart of a method for producing bio-jet fuel from high-acid value oils and fats provided in a specific embodiment of the present invention.

[0038] In the figure: 1 high acid value oil, 2 deacidification pretreatment catalyst, 3 slurry bed reactor, 4 effluent, 5 solid-liquid separator, 6 solid tailings, 7 liquid product, 8 fixed bed hydrodeoxygenation reactor, 9 fixed bed hydrocracking reactor, 10 fixed bed hydroisomerization reactor, 11 gas-liquid separation unit, 12 fractionation unit. DETAILED DESCRIPTION

[0039] The method provided by the present invention is further described below in conjunction with the accompanying drawings. The drawings omit equipment such as pumps, heat exchangers, and compressors, but these are well known to those skilled in the art.

[0040] The specific embodiment of the present invention provides a detailed process of a method for producing bio-jet fuel from high acid value oil, such as Figure 1 As shown, including:

[0041] The high acid value oil 1 from the pipeline is fully mixed with the deacidification pretreatment catalyst 2 to form a mixture, and the mixture enters the slurry bed reactor 3 for deacidification pretreatment to obtain an effluent 4. The reaction conditions in the slurry bed reactor 3 are: the nitrogen partial pressure in the reactor is 0.2-5 MPa, the reaction temperature is 280-400°C, and the liquid hourly volume space velocity is 0.2-3.5 h -1 .

[0042] The effluent 4 is passed through a solid-liquid separator 5 for solid-liquid separation to obtain a liquid product 7 and a solid tailings 6, the solid tailings 6 is discharged, and the liquid product 7 is sequentially passed through a fixed bed hydrodeoxygenation reactor 8, a fixed bed hydrocracking reactor 9 and a fixed bed hydroisomerization reactor 10 connected in series for hydrogenation reaction to obtain a hydrogenated product.

[0043] The reaction conditions of the fixed bed hydrodeoxygenation reactor 8 are as follows: the hydrogen partial pressure in the reactor is 4-10 MPa, the reaction temperature is 280-390°C, the liquid hourly volume space velocity is 0.2-3 h -1The volume ratio of hydrogen to the material entering the reactor is 200-1200; the reaction conditions of the fixed bed hydrocracking reactor are: the hydrogen partial pressure in the reactor is 5-10 MPa, the reaction temperature is 300-390°C, and the liquid hourly volume space velocity is 0.2-3h -1 The volume ratio of hydrogen to the material entering the reactor is 200-1200; the reaction conditions of the fixed bed hydroisomerization reactor are: hydrogen partial pressure in the reactor is 4-10MPa, reaction temperature is 250-350℃, liquid hourly volume space velocity is 0.2-3h -1 , the volume ratio of hydrogen to the material entering the reactor is 200 to 1200.

[0044] The hydrogenation product enters the gas-liquid separation unit 11 for gas-liquid separation, and the obtained liquid product enters the fractionation unit 12 to finally obtain a naphtha fraction, a bio-jet fuel fraction and a biodiesel fraction.

[0045] The specific embodiment of the present invention adopts a universal fixed-bed hydrodeoxygenation reactor 8, a fixed-bed hydrocracking reactor 9 and a fixed-bed hydroisomerization reactor 10.

[0046] Example 1

[0047] In this embodiment, the high acid value oil 1 is acidified palm oil, and its main properties are shown in Table 1. The acidified palm oil from the pipeline is fully mixed with the MgO catalyst to form a mixture, and the mixture enters the slurry bed reactor 3 for deacidification pretreatment to obtain an effluent 4. The reaction conditions in the slurry bed reactor 3 are: the nitrogen partial pressure in the reactor is 1 MPa, the reaction temperature is 300°C, and the liquid hourly volume space velocity is 0.8 h -1 .

[0048] The present embodiment provides a method for preparing a catalyst for the deacidification pretreatment of high-acid value oils and fats: weigh 30.6 g of magnesium nitrate and dissolve it in 130 mL of deionized water to obtain a clear metal salt solution; add ammonia water dropwise to the metal salt solution while stirring until the precipitation is complete; filter the precipitate and dry it in an oven at 60°C for 8 hours, grind the dried catalyst thoroughly, and calcine it at 550°C for 6 hours to obtain a MgO catalyst with a particle size of 0.05 μm. The deacidification reaction conditions of the slurry bed reactor are shown in Table 2, and the deacidification pretreatment reaction results of the slurry bed reactor are shown in Table 3.

[0049] The effluent 4 is passed through a solid-liquid separator 5 for solid-liquid separation to obtain a liquid product 7 and a solid tailings 6. The solid tailings 6 are discharged from the device, and the liquid product 7 is sequentially passed through a fixed bed hydrodeoxygenation reactor 8, a fixed bed hydrocracking reactor 9 and a fixed bed hydroisomerization reactor 10 connected in series for hydrogenation reaction to obtain a hydrogenated product.

[0050] Among them, the hydrodeoxygenation catalyst, hydrocracking catalyst and hydroisomerization catalyst can be selected from common commercial catalysts in this field. This embodiment uses the hydrorefining catalyst ST-313, hydrocracking catalyst HC-470 and isomerization catalyst I-82 developed by a certain company. The reaction conditions of the fixed bed hydrodeoxygenation reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 340℃, and the liquid hourly volume space velocity is 1.5h -1 , the volume ratio of hydrogen to oil is 800; the reaction conditions of the fixed bed hydrocracking reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 370℃, the liquid hourly volume space velocity is 2h -1 , the hydrogen volume ratio is 600; the reaction conditions of the fixed bed isomerization reactor are: the hydrogen partial pressure in the reactor is 4MPa, the reaction temperature is 300℃, the liquid hourly volume space velocity is 2.5h -1 , the hydrogen volume ratio is 400.

[0051] The hydrogenation product enters the gas-liquid separation unit 11 for gas-liquid separation, and the obtained liquid product enters the fractionation unit 12 to finally obtain the bio-jet fuel fraction. The results obtained by distillation are shown in Table 4.

[0052] Example 2

[0053] In this embodiment, the high acid value oil 1 is used as the kitchen waste oil. Its main properties are shown in Table 1. The kitchen waste oil from the pipeline is mixed with ZrO 2 The catalyst is fully mixed to form a mixture, which enters the slurry bed reactor 3 and undergoes deacidification pretreatment to obtain an effluent 4. The reaction conditions in the slurry bed reactor 3 are: the nitrogen partial pressure in the reactor is 1.5 MPa, the reaction temperature is 320°C, and the liquid hourly volume space velocity is 2 h -1 .

[0054] The preparation method of the catalyst for high acid value oil deacidification pretreatment provided in this embodiment is as follows: 28.3 g of zirconium nitrate is weighed and dissolved in 130 mL of deionized water to obtain a clear metal salt solution; sodium carbonate solution is added dropwise to the metal salt solution under stirring until precipitation is complete; the precipitate is filtered and placed in an oven at 80° C. to dry for 12 h; the dried catalyst is fully ground and calcined at 650° C. for 8 hours to obtain ZrO 2 Catalyst, the particle size of the catalyst is 0.01 μm, the deacidification reaction conditions of the slurry bed reactor are shown in Table 2, and the deacidification pretreatment reaction results of the slurry bed reactor are shown in Table 3.

[0055] The effluent 4 is passed through a solid-liquid separator 5 for solid-liquid separation to obtain a liquid product 7 and a solid tailings 6. The solid tailings 6 are discharged from the device, and the liquid product 7 is sequentially passed through a fixed bed hydrodeoxygenation reactor 8, a fixed bed hydrocracking reactor 9 and a fixed bed hydroisomerization reactor 10 connected in series for hydrogenation reaction to obtain a hydrogenated product.

[0056] Among them, the hydrodeoxygenation catalyst, hydrocracking catalyst and hydroisomerization catalyst can be selected from common commercial catalysts in this field. This embodiment uses the hydrorefining catalyst ST-313, hydrocracking catalyst HC-470 and isomerization catalyst I-82 developed by a certain company. The reaction conditions of the fixed bed hydrodeoxygenation reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 340℃, and the liquid hourly volume space velocity is 1.5h -1 , the volume ratio of hydrogen to oil is 800; the reaction conditions of the fixed bed hydrocracking reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 370℃, the liquid hourly volume space velocity is 2h -1 , the hydrogen volume ratio is 600; the reaction conditions of the fixed bed isomerization reactor are: the hydrogen partial pressure in the reactor is 4MPa, the reaction temperature is 300℃, the liquid hourly volume space velocity is 2.5h -1 , the hydrogen volume ratio is 400.

[0057] The hydrogenation product enters the gas-liquid separation unit 11 for gas-liquid separation, and the obtained liquid product enters the fractionation unit 12 to finally obtain the bio-jet fuel fraction. The results obtained by distillation are shown in Table 5.

[0058] Example 3

[0059] In this embodiment, high acid value oil 1 is used as the acidified oil. Its main properties are shown in Table 1. The acidified oil from the pipeline is mixed with Ba(OH) 2 The catalysts are fully mixed to form a mixture, which enters the slurry bed reactor 3 and undergoes deacidification pretreatment to obtain an effluent 4. The reaction conditions in the slurry bed reactor 3 are: the nitrogen partial pressure in the reactor is 3 MPa, the reaction temperature is 350°C, and the liquid hourly volume space velocity is 2 h -1 .

[0060] The preparation method of the catalyst for high acid value oil deacidification pretreatment provided in this embodiment is as follows: 26.9 g of barium nitrate is weighed and dissolved in 130 mL of deionized water to obtain a clear metal salt solution; potassium hydroxide solution is added dropwise to the metal salt solution under stirring until precipitation is complete; the precipitate is filtered and placed in an oven at 100° C. to dry for 1 hour, and the dried catalyst is fully ground to obtain Ba(OH) 2 Catalyst, the particle size of the catalyst is 200 μm, the deacidification reaction conditions of the slurry bed reactor are shown in Table 2, and the deacidification pretreatment reaction results of the slurry bed reactor are shown in Table 3.

[0061] The effluent 4 is passed through a solid-liquid separator 5 for solid-liquid separation to obtain a liquid product 7 and a solid tailings 6. The solid tailings 6 are discharged from the device, and the liquid product 7 is sequentially passed through a fixed bed hydrodeoxygenation reactor 8, a fixed bed hydrocracking reactor 9 and a fixed bed hydroisomerization reactor 10 connected in series for hydrogenation reaction to obtain a hydrogenated product.

[0062] Among them, the hydrodeoxygenation catalyst, hydrocracking catalyst and hydroisomerization catalyst can be selected from common commercial catalysts in this field. This embodiment uses the hydrorefining catalyst ST-313, hydrocracking catalyst HC-470 and isomerization catalyst I-82 developed by a certain company. The reaction conditions of the fixed bed hydrodeoxygenation reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 340℃, and the liquid hourly volume space velocity is 1.5h -1 , the volume ratio of hydrogen to oil is 800; the reaction conditions of the fixed bed hydrocracking reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 370℃, the liquid hourly volume space velocity is 2h -1 , the hydrogen volume ratio is 600; the reaction conditions of the fixed bed isomerization reactor are: the hydrogen partial pressure in the reactor is 4MPa, the reaction temperature is 300℃, the liquid hourly volume space velocity is 2.5h -1 , the hydrogen volume ratio is 400.

[0063] The hydrogenation product enters the gas-liquid separation unit 11 for gas-liquid separation, and the obtained liquid product enters the fractionation unit 12 to finally obtain the bio-jet fuel fraction. The results obtained by distillation are shown in Table 6.

[0064] Example 4

[0065] In this embodiment, the high acid value oil 1 is acidified palm oil, and its main properties are shown in Table 1. The acidified palm oil from the pipeline is mixed with Ti(OH) 4 The catalysts are fully mixed to form a mixture, which enters the slurry bed reactor 3 for deacidification pretreatment to obtain an effluent 4. The reaction conditions in the slurry bed reactor 3 are: the nitrogen partial pressure in the reactor is 3.5 MPa, the reaction temperature is 360°C, and the liquid hourly volume space velocity is 2.8 h -1 .

[0066] The preparation method of the catalyst for high acid value oil deacidification pretreatment provided in this embodiment is as follows: 24.7 g of titanium sulfate is weighed and dissolved in 130 mL of deionized water to obtain a clear metal salt solution; potassium carbonate solution is added dropwise to the metal salt solution under stirring until precipitation is complete; the precipitate is filtered and placed in an oven at 100° C. for 5 h, and the dried catalyst is fully ground to obtain Ti(OH) 4 Catalyst, the particle size of the catalyst is 500 μm, the deacidification reaction conditions of the slurry bed reactor are shown in Table 2, and the deacidification pretreatment reaction results of the slurry bed reactor are shown in Table 3.

[0067] The effluent 4 is passed through a solid-liquid separator 5 for solid-liquid separation to obtain a liquid product 7 and a solid tailings 6. The solid tailings 6 are discharged from the device, and the liquid product 7 is sequentially passed through a fixed bed hydrodeoxygenation reactor 8, a fixed bed hydrocracking reactor 9 and a fixed bed hydroisomerization reactor 10 connected in series for hydrogenation reaction to obtain a hydrogenated product.

[0068] Among them, the hydrodeoxygenation catalyst, hydrocracking catalyst and hydroisomerization catalyst can be selected from common commercial catalysts in this field. This embodiment uses the hydrorefining catalyst ST-313, hydrocracking catalyst HC-470 and isomerization catalyst I-82 developed by a certain company. The reaction conditions of the fixed bed hydrodeoxygenation reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 340℃, and the liquid hourly volume space velocity is 1.5h -1 , the volume ratio of hydrogen to oil is 800; the reaction conditions of the fixed bed hydrocracking reactor are: the hydrogen partial pressure in the reactor is 6MPa, the reaction temperature is 370℃, the liquid hourly volume space velocity is 2h -1 , the hydrogen volume ratio is 600; the reaction conditions of the fixed bed isomerization reactor are: the hydrogen partial pressure in the reactor is 4MPa, the reaction temperature is 300℃, the liquid hourly volume space velocity is 2.5h -1 , the hydrogen volume ratio is 400.

[0069] The hydrogenation product enters the gas-liquid separation unit 11 for gas-liquid separation, and the obtained liquid product enters the fractionation unit 12 to finally obtain the bio-jet fuel fraction. The results obtained by distillation are shown in Table 7.

[0070] Table 1 Main properties of high acid value oil raw materials

[0071] project Acidified palm oil Waste cooking oil acidified oil Acid value (mg KOH / g) 173 158 187 Total metals (mg / kg) 112 87 79 Oxygen content (%) 12.1 11.4 12.6 Chlorine content (ppm) 40.3 54.5 60.4 Sulfur content (ppm) 30.7 46.5 39.3 Nitrogen content (ppm) 5.1 4.2 2.8 Condensation point(℃) 23 25 25 <![CDATA[Density (g / cm 3 )]]> 0.91 0.90 0.90

[0072] Table 2 Reaction conditions for deacidification pretreatment of high acid value oil slurry bed

[0073]

[0074] Table 3 High acid value oil slurry bed deacidification pretreatment reaction results

[0075]

[0076]

[0077] Table 4 Example 1 Full process reaction results of high acid value oil hydrogenation to produce bio-jet fuel

[0078]

[0079] Table 5 Example 2 High acid value oil hydrogenation to produce bio-jet fuel full process reaction results

[0080]

[0081]

[0082] Table 6 Example 3 Full process reaction results of high acid value oil hydrogenation to produce bio-jet fuel

[0083]

[0084] Table 7 Example 4 High acid value oil hydrogenation to produce bio-jet fuel full process reaction results

[0085]

[0086] It can be seen from the results in Table 3 that the high acid value oils and fats are treated according to the slurry bed reactor deacidification pretreatment process adopted by the method provided in Examples 1 to 4 of the present invention. After pretreatment, the acid value of the oils and fats is reduced to below 1 mg KOH / g, and other impurity indicators such as chlorine, nitrogen, sulfur, and total metals are significantly reduced, thereby achieving efficient removal of non-ideal components in high acid value oils and fats, and meeting the requirements for raw materials for subsequent further hydrogenation treatment.

[0087] From the results in Tables 4 to 7, it can be seen that high-acid value oils and fats are treated according to the methods provided in Examples 1 to 4 of the present invention to obtain high-quality naphtha, bio-jet fuel fractions and biodiesel fractions. Therefore, the method for producing bio-jet fuel by hydrogenating waste oils and fats provided by the specific implementation of the present invention has the advantages of simple process flow, high oil liquid yield, good bio-jet fuel quality, etc., and can realize the resource utilization of all fractions of high-acid value oils and fats.

[0088] For ordinary technicians in this field, the specific embodiments are only illustrative descriptions of the present invention. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concepts and technical solutions of the present invention, or the concepts and technical solutions of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for producing bio-jet fuel from high acid value oil, characterized in that: include: S1, mixing a high-acid value oil from which mechanical impurities have been removed and a deacidification pretreatment catalyst to obtain a mixture, and adding the mixture to a slurry bed reactor for deacidification pretreatment to obtain an effluent; S2, performing solid-liquid separation on the effluent obtained in step S1 to obtain a liquid product, and sequentially passing the liquid product through a fixed bed hydrodeoxygenation reactor, a fixed bed hydrocracking reactor and a fixed bed hydroisomerization reactor connected in series to perform hydrogenation treatment to obtain a hydrogenated product; S3. Separate the hydrogenation product into gas and liquid to obtain a liquid product, and fractionate the liquid product to obtain a bio-jet fuel fraction.

2. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The deacidification pretreatment catalyst is a metal oxide or hydroxide of Group IIA or Group IV, the Group IIA element is Be, Mg, Sr or Ba, and the Group IV metal is Ti or Zr.

3. The method for producing bio-jet fuel from high acid value oil according to claim 2, characterized in that: The deacidification pretreatment catalyst is MgO or ZrO.

4. The method for producing bio-jet fuel from high acid value oil according to claim 3, characterized in that: The deacidification pretreatment catalyst is MgO.

5. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The size of the deacidification pretreatment catalyst is 0.005-600 μm.

6. The method for producing bio-jet fuel from high acid value oil according to claim 5, characterized in that: The size of the deacidification pretreatment catalyst is 0.01-0.05 μm.

7. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The preparation method of the deacidification pretreatment catalyst comprises: Adding a precipitant to a soluble salt solution of Be, Mg, Sr, Ba, Ti or Zr metal, and drying at 60 to 120° C. for 0.5 to 12 hours to obtain a metal hydroxide; Alternatively, the metal hydroxide is calcined at 350-750° C. for 5-12 hours to obtain the metal oxide, and the calcination atmosphere is nitrogen or argon.

8. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The added amount of the deacidification pretreatment catalyst accounts for 0.1-10% of the weight of the high acid value oil.

9. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The reaction conditions of the slurry bed reactor are: nitrogen partial pressure of 0.2-5 MPa, reaction temperature of 280-400°C, liquid hourly volume space velocity of 0.2-3.5 h -1 , the temperature difference of the axial temperature of the slurry bed reactor does not exceed 10°C; The reaction conditions of the fixed bed hydrodeoxygenation reactor are: hydrogen partial pressure 4-10 MPa, reaction temperature 280-390°C, liquid hourly volume space velocity 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the fixed bed hydrodeoxygenation reactor is 200 to 1200; The reaction conditions of the fixed bed hydrocracking reactor are: hydrogen partial pressure of 5-10 MPa, reaction temperature of 300-390°C, liquid hourly volume space velocity of 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the reactor is 200 to 1200; The reaction conditions of the fixed bed hydroisomerization reactor are: hydrogen partial pressure 4-10 MPa, reaction temperature 250-350° C., liquid hourly volume space velocity 0.2-3 h -1 , the volume ratio of hydrogen to the material entering the reactor is 200 to 1200.

10. The method for producing bio-jet fuel from high acid value oil according to claim 1, characterized in that: The high acid value oil is one or more of acidified oil, waste cooking oil, acidified palm oil, rancid vegetable oil, and rancid animal oil.

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