CN107974266B - Method and system for producing aviation fuel components from waste oil - Google Patents

Abstract

The invention relates to a method and a system for producing aviation fuel components from waste grease, which comprises the following steps: the invention takes waste grease as raw material to react with methanol, replace glycerin, remove chlorine and metal in the raw material and reduce the acid value of the raw material, and then produces aviation fuel components meeting the product requirements through hydrodeoxygenation and selective cracking reaction, thus realizing the effective utilization of waste grease resources.

Description

A method and system for producing aviation fuel components from waste grease

technical field

The present invention belongs to a method for producing biofuel, more specifically, a method and system for producing aviation fuel components from waste grease.

Background technique

With the tightening of traditional fossil energy supply and the increasing pressure on carbon dioxide emission reduction, the development of renewable and clean alternative energy has become a global consensus.

Liquid fuels, such as gasoline, diesel and jet fuel, are a major source of carbon dioxide emissions to the atmosphere. Most of these liquids come from oil, natural gas and coal. Compared with fossil fuels, biomass-derived fuels absorb carbon dioxide during the growth process, which can effectively reduce carbon dioxide emissions compared to fossil fuels. Therefore, biofuels are considered to be one of the most ideal ways to reduce carbon dioxide emissions in the transportation industry.

Among the raw materials for preparing biofuels, animal and vegetable oils and fats are the main raw materials. However, when developing biofuels, we must follow the principle of not competing with people for food and not competing with food for land. Therefore, inedible and waste oils and fats are an inevitable choice for the development of biofuels.

Waste oils and fats refer to oil wastes that lose their edible value and are produced during the processing and consumption of natural oils (vegetable oils and animal fats), including scraps produced during the production of edible oils from oil crops, households, hotels, catering industries and Food production enterprises use the frying oil and kitchen oil produced in edible oil, animal fat by-products in meat production and processing, and edible oil beyond the shelf life. It is conservatively estimated that China produces more than 10 million tons of waste oil every year.

Improper disposal of waste oil will become a serious source of pollution, polluting the land, water and atmosphere. Waste oils were once used as animal feed additives or used to produce detergent products, but it was later found that such use would continue their harm to human beings and could only be harmlessly treated as pollutants, but the treatment was difficult and expensive.

The traditional process of converting oils and fats into liquid fuels is the transesterification method. Transesterification using methanol and oils can convert oils and fats into fatty acid methyl esters and glycerol. The products are usually fatty acid methyl esters (also known as first-generation biodiesel). Transesterification methods mainly include: acid catalysis, base catalysis, enzyme catalysis and supercritical technology. However, the reaction catalyzed by acid and alkali has high requirements on raw materials, and cannot directly treat waste oil. Supercritical technology can directly treat waste oil.

However, when using waste oil to produce biodiesel, the acid value of biodiesel often cannot meet the requirements of product quality standards. For example, European and American standards and the newly revised national standard to be released in my country have higher requirements on the acid value of products, that is, not more than 0.5mgKOH/ g. In order to reduce the acid value of the product, further processing is required, which increases the investment and operating costs of the device. Moreover, the poor low temperature fluidity of fatty acid methyl esters limits its use in colder ambient conditions, while the presence of carbon-carbon double bonds reduces the stability of fatty acid methyl esters. Due to the presence of oxygen atoms in fatty acid methyl esters, higher NOx emissions are caused during the combustion process. Fatty acid methyl ester needs to be mixed with traditional diesel oil during use, and the mixing ratio is generally not more than 10%.

Another method of converting oil into liquid fuel is the hydrogenation method, which converts oil into hydrocarbon fuel through hydrodeoxygenation. Compared with the first generation of biodiesel, it contains no oxygen elements and has a cetane number of 70 to 100. , has better storage stability, and can be blended with traditional petroleum-based diesel in any proportion. In addition, facing the dual pressure of carbon dioxide emission reduction and carbon tax, the aviation industry has high expectations for aviation fuel derived from biomass, and believes that biofuel is the only option to achieve carbon dioxide emission reduction goals.

However, there are many types of waste oils, complex sources, scattered channels, and unstable impurity composition and content, so fixed bed hydroprocessing cannot be carried out directly. For example, the content of free fatty acids in waste oil is very wide, from 1% to more than 80%. Too high free fatty acid content will increase the requirements for equipment corrosion protection; waste oil also contains a variety of impurities, including inherent phospholipids, As well as collecting colloids, soaps, heteroatomic organics, etc. produced by oxidation during processing; especially the presence of chlorine-containing compounds is more harmful, and inorganic acids will be generated in the subsequent hydrogenation process, aggravating equipment corrosion and inducing safety. ACCIDENT. Therefore, it is necessary to reduce the acid value of the raw material and remove impurities such as colloid, metal ions and chlorine from the raw material before hydrogenation, so as to reduce the corrosion of the equipment, prolong the service life of the catalyst, and improve the continuity of production. As disclosed in CN101583694, the method for producing hydrocarbon fractions from biogenic mixtures requires pretreatment of the feedstock prior to hydrodeoxygenation. The pretreatment methods include absorption, treatment with ion exchange resins or weakly acidic detergents. In the method for preparing diesel range hydrocarbons disclosed in CN101233212, the alkali metal or alkaline earth metal in the raw material is limited to be less than 10 mg/kg.

CN102504866 discloses a method for preparing biodiesel from kitchen waste oil. The method adopts the method of water washing to pretreat the kitchen waste oil to remove the metal in the raw material. Then, the pretreated raw material is subjected to hydrodemetallization, degumming and partial deoxygenation; it is mixed with mineral oil and then subjected to two-stage hydrogenation, and finally, the product properties are improved by hydrocracking or isomerization. The pretreatment of kitchen waste oil by washing with water can only partially remove the metals in the raw materials, but does not improve the chlorine in the raw materials and the acid value of the raw materials.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the deficiencies of the prior art and provide a method for producing aviation fuel components from waste grease.

The method provided by the present invention comprises the following steps:

(1) waste oil methyl esterification unit, waste oil and methanol carry out alcoholysis reaction after mixing, boosting and heating, obtain thick glycerol and thick methyl ester, and thick methyl ester obtains refined methyl ester through flash evaporation;

(2) hydrotreating reaction unit, the refined methyl ester obtained in step (1) is contacted with a hydrotreating catalyst in the presence of hydrogen, and a deoxygenation reaction is carried out under hydrotreating conditions to obtain a hydrotreating product; Described hydrotreating catalyst comprises a carrier of composite alumina and a hydrogenation active component supported on the carrier, at least one of said hydrogenation active components is selected from group VIII and at least one is selected from group VIB. Metal component, the alumina carrier includes the step of being treated with steam in the preparation process;

(3) hydroconversion reaction unit, the obtained hydroprocessing product of step (2) is contacted with a hydroconversion catalyst in the presence of hydrogen, and a selective cracking reaction is carried out under hydroconversion conditions to obtain hydroconversion product;

(4) Separation and fractionation unit, after separation and fractionation of the generated oil obtained by hydroconversion in step (3), kerosene components and diesel components are obtained.

The content of the present invention is further described as follows:

(1) Waste oil methyl esterification unit

The waste oil and methanol are mixed, pressurized and heated to undergo alcoholysis reaction to obtain crude glycerol and crude methyl ester; crude glycerol is refined to produce glycerol products; crude methyl ester is flashed to obtain refined methyl ester and heavy oil. After the methyl esterification reaction, methanol converts the glycerol group in the oil into glycerol, and the impurities of the raw material are enriched in the heavy oil, so as to replace the glycerol, remove the chlorine and metal in the raw material, and reduce the acid value of the raw material.

The operating conditions of the waste oil methyl esterification unit are: the temperature of the alcoholysis reaction between the waste oil and methanol is 180-320°C, preferably 220-300°C, more preferably 240-280°C; the reaction pressure is 4-10MPa, preferably 5- 8MPa; the mass ratio of methanol to grease is 0.2-1:1, preferably 0.3-0.7:1; the reaction time is 30-120min, preferably 60-90min.

According to the method provided by the present invention, the mixed material after the alcoholysis reaction enters a rectifying tower, and the methanol is extracted by rectifying.

In the present invention, in the methyl esterification unit of waste oils and fats, a crude methyl ester glycerol sedimentation separator and a crude methyl ester flash vessel are arranged, and the mixture material after the alcoholysis reaction is separated into methanol and then enters into the crude methyl ester glycerin sedimentation separator to separate The separator is operated continuously, and the operating conditions are as follows: the temperature of the material is kept at 40-80°C, preferably 50-70°C; the residence time is preferably 0.5h-3h, preferably 1-2h; after the sedimentation is completed, the crude methyl ester leaves the upper part of the separator and enters the crude The methyl ester flashing vessel, the crude glycerin leaves from the lower part of the separator, and can be further refined; the crude methyl ester is flashed to obtain refined methyl ester, and the crude methyl ester flashing vessel is a flashing tank or a flashing tower.

According to the method provided by the invention, the purpose of flashing the crude methyl ester is to realize the separation of the methyl ester and the heavy oil to obtain the refined methyl ester. The crude methyl ester flash vessel is a flash tank or a flash tower, and the operating conditions of the flash tower are: temperature 220-350°C, preferably 260-320°C; pressure 2-0.3kPa, preferably 1.5-0.5kPa.

In the obtained refined methyl ester, the content of fatty acid methyl ester exceeds 95%, the content of sulfur is not more than 10 μg/g, the content of Cl is not more than 1 μg/g, and the sum of the content of various metal ions is not more than 2 μg/g.

In the method provided by the present invention, the waste oil and fat is the oil and fat waste that is unfit for consumption and is produced in the processing and consumption of animal and vegetable oil. Including fatty acids, acidified oil, etc. produced in the process of producing edible oil from oil; households, hotels, catering industry and food production enterprises use cooking oil such as frying oil, kitchen oil, stagnant oil and other catering waste oil; Animal fats by-products in meat production and processing, and edible oils beyond their expiration dates.

In the process of oil hydrogenation, the glycerol group in the oil will be hydrogenated to form propane. If the propane is recovered, the investment of the equipment needs to be increased. Glycerol is an important chemical raw material, which can be used directly or prepared by biological and chemical processing to prepare other chemical products. As a chemical raw material, methanol has a wide range of sources and is cheaper than glycerol. Replacing high-value glycerol with low-cost methanol can increase the value of waste oil and reduce the production cost of biofuels; and through transesterification, the pretreatment of waste oil can also be achieved to meet the needs of subsequent hydrogenation processes.

(2) Hydrotreating reaction unit

In the presence of hydrogen, the purified methyl ester obtained in step (1) is contacted with a hydrotreating catalyst, and deoxygenation is carried out under hydrotreating conditions to obtain a hydrotreating product.

The reaction conditions of the hydrotreating reaction unit are as follows: the reaction temperature is 200-400°C, the hydrogen partial pressure is 1.0-10.0MPa, the liquid hourly volume space velocity is 0.5-10.0h ^-1 , and the hydrogen-oil volume ratio is 500-1500Nm ³ /m ³ . Under the reaction conditions and the action of the catalyst, the mixed material undergoes reactions such as hydrodeoxygenation, olefin saturation and hydrodesulfurization, and the reaction is a strong exothermic reaction.

In a preferred embodiment of the present invention, part of the liquid phase material in the hydroprocessing product is recycled to the inlet of the hydroprocessing reaction unit, and the mass ratio of refined methyl ester to the recycled liquid phase material is 1:2 to 1:6.

According to the method provided by the present invention, the hydroprocessing catalyst uses alumina as a carrier and a hydrogenation active component supported on the carrier, and at least one of the hydrogenation active components is selected from Group VIII and at least one A metal component selected from group VIB. The alumina carrier includes a steam treatment step in the preparation process. Preferably, the alumina carrier does not include a calcination step in the preparation process. A large amount of water will be generated during the hydrodeoxygenation of raw materials, and the presence of water vapor will affect the stability of the catalyst, especially the catalyst carrier. According to the method provided by the present invention, the carrier of the used catalyst is treated with steam without calcination, which can obviously stabilize the properties of the carrier, thereby avoiding the influence of water generated in the hydrotreating reaction process on the hydrotreating catalyst.

According to the method provided by the present invention, the preparation step of the hydrotreating catalyst comprises:

(1) Mixing hydrated alumina and drying;

(2) carrying out water vapor treatment to obtain a carrier;

(3) The carrier obtained in step (2) is immersed in the prepared aqueous solution containing hydrogenation active components, and then dried and roasted to obtain a hydrogenation catalyst.

The hydrated alumina is pseudoboehmite. The drying conditions of step (1) are: temperature 80-200° C., time 1-24 hours.

The conditions of step (2) the water vapor treatment step include: temperature of 450-750° C., time of 4-8 hours, and water-vapor flow rate of 0.5-5.0 standard cubic meters/kg carrier·hour.

In step (3), the dipping conditions are as follows: the temperature is 20-100° C., and the time is 1-24 hours.

The conditions of calcination in step (3) are: the temperature is 400-650° C., and the time is 2-6 hours.

In the hydrotreating catalyst, preferably, the metal component of Group VIII is cobalt and/or nickel, and the metal component of Group VIB is molybdenum and/or tungsten. In terms of oxide and based on the catalyst, the metal component of Group VIII is The content of the component is 1-10 wt %, and the content of the VIB group metal component is 10-45 wt %.

The aqueous solution containing hydrogenation active components, such as the compound aqueous solution of cobalt, molybdenum, nickel and tungsten, can be prepared by conventional methods. The compounds of cobalt, molybdenum, nickel and tungsten are selected from one or more of their soluble compounds, respectively. The molybdenum compound is preferably ammonium molybdate, and the tungsten compound is preferably one or more of ammonium tungstate, ammonium metatungstate, ethyl ammonium metatungstate, and nickel metatungstate. The compounds of nickel and cobalt are preferably one or more of nickel nitrate, cobalt nitrate, nickel chloride, cobalt chloride, basic nickel carbonate and basic cobalt carbonate, respectively.

Before use, the hydrotreating catalyst is sulfided by conventional sulfidation methods to convert the metal in the oxidation state to the metal in the sulfide state. The hydrogenation active metal changes from the oxidized state to the sulfurized state, which is beneficial to improve the activity and stability of the catalyst. The oil basically does not contain sulfur, so in the process of hydrotreating, in order to maintain the sulfur state of the catalyst, it is necessary to ensure the sulfur content in the feed. The feed of the hydrotreating reaction unit contains a vulcanizing agent, which is 100-5000 mg/kg in terms of elemental sulfur, and the vulcanizing agent is selected from H ₂ S, CS ₂ , dimethyl disulfide, methyl sulfide , one or more of n-butyl sulfide and thiophene.

According to the method provided by the present invention, the reactor of the hydrotreating reaction unit is preferably a fixed bed reactor, the catalyst bed is divided into at least 3 catalyst beds, and the bed temperature can be adjusted by injecting cold hydrogen between the catalyst beds. control. Through the coordination of diluent oil and cold hydrogen, the hydrotreating reaction can be controlled stably, and the temperature rise of the catalyst bed can be controlled in an appropriate range.

After the hydrotreating of refined methyl ester, alkanes with carbon number of C ₈ -C ₂₄ , water, CO, CO ₂ and CH ₄ are mainly produced. The gas phase product contains a large amount of hydrogen and impurities such as CO, CO ₂ , H ₂ S, CH ₄ , etc., which can be purified by CO shift, PAS pressure swing adsorption or steam reforming and then recycled. The generated C ₈ -C ₂₄ alkanes enter the hydroconversion reaction unit after dehydration.

(3) Hydroconversion reaction unit

The hydroprocessing product obtained in step (2) is contacted with a hydroconversion catalyst in the presence of hydrogen, and a selective cracking reaction is carried out under hydroconversion conditions to obtain a hydroconversion product. In the reaction process, the C ₈ -C ₂₄ alkanes are selectively cracked and isomerized to obtain mixed components containing C ₉ -C ₁₆ isoparaffins. In this unit, the low temperature performance of the product is effectively improved and adjusted. Product distillation range distribution.

The reaction conditions in the hydroconversion reaction unit are: the reaction temperature is 200～500℃, preferably 300～380℃; the hydrogen partial pressure is 1.0～10.0Mpa, preferably 3.0～8.0MPa; the liquid hourly volume space velocity is 0.1～5.0h ^{− 1} , preferably 0.5-3.0 h ^-1 ; the volume ratio of hydrogen to oil is 300-1200Nm ³ /m ³ , preferably 400-800:1.

The hydroconversion catalyst contains a molecular sieve with a one-dimensional mesoporous structure, a heat-resistant inorganic oxide matrix and a hydrogenation metal component.

Based on the total amount of the hydroconversion catalyst, the content of the one-dimensional mesoporous molecular sieve is 20-80 wt %, the alumina content is 15-75 wt %, and the hydrogenation metal content is 0.2-75 wt % in terms of oxides. 5% by weight, the sum of the above components is 100%. Preferably, the hydrogenation metal component is selected from one or more of cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, molybdenum and tungsten. The one-dimensional mesoporous molecular screening is selected from one or more of ZSM-22, Nu-10, Thete-1, ISI-1, ZSM-23, SAPO-11, SAPO-31, and SAPO-41.

The metal active components of the hydroconversion catalyst are in a reduced state, and the catalyst needs to be reduced before use, and the reduction technology is a conventional technology.

The preferred hydroconversion catalyst of the present invention has suitable acidity and hydrogenation activity, and can achieve selective cracking to obtain C ₉ -C ₁₆ isoparaffins in high yield, while meeting the aviation fuel product standards such as freezing point, distillation range, viscosity, etc. .

Due to the hydrocracking reaction in the whole reaction process, a large amount of reaction heat will be generated. If the temperature rise of the reactor cannot be controlled properly, more secondary cracking reactions will be triggered, resulting in a decrease in the yield of the target product. According to the method provided by the present invention, the reactor of the hydroconversion reaction unit is preferably a fixed-bed reactor, the catalyst bed is two or more catalyst beds, and the catalyst beds can be cooled by injecting cold hydrogen between the catalyst beds. temperature is controlled.

(4) Product Fractionation

The kerosene component and the diesel component are obtained after separation and fractionation of the generated oil obtained by the hydrogenation conversion in step (3).

The present invention provides a system for producing aviation fuel components from waste grease, comprising:

(1) waste oil methyl esterification unit, set up alcoholysis reactor, rectifying tower, thick methyl ester glycerol sedimentation separation zone, thick methyl ester flash vessel, waste oil and methanol carry out alcoholysis reaction in alcoholysis reactor, The mixed material after the alcoholysis reaction enters the rectifying tower to extract methanol; the mixed material after separating the methanol enters the crude methyl ester glycerin sedimentation separator, the upper part of the crude methyl methyl glycerin sedimentation separator is provided with a crude methyl ester extraction line, and the lower part is provided with a crude glycerin The extraction line, the crude methyl ester extraction line is connected with the inlet of the crude methyl ester flash container, and the crude methyl ester flash container is provided with a refined methyl ester extraction line and a heavy oil extraction line;

(2) hydrotreating reaction unit, the hydrotreating reaction unit is provided with a hydrotreating reactor, wherein a hydrotreating catalyst is loaded, and the refined methyl ester extraction line from the waste oil and fat methylation unit is connected with the hydrotreating reactor inlet, The outlet of the hydrotreating reactor is connected to the inlet of the separation and fractionation unit. The separation and fractionation unit is provided with a gas phase material outlet and a liquid phase material outlet. The liquid phase material outlet is connected to the liquid phase material circulation line and the liquid phase material extraction line, and the liquid phase material circulation line is connected to The inlet of the hydrotreating reactor is connected;

(3) hydroconversion reaction unit, the hydroconversion reaction unit is provided with a hydroconversion reactor, wherein a hydroconversion catalyst is loaded, and the liquid phase material draw-off line from the hydrotreating reaction unit is connected with the hydroconversion reactor inlet, adding The outlet of the hydroconversion reactor is connected with the extraction line of the hydroconversion reaction product;

(4) Separation and fractionation unit, the extraction line of the hydroconversion reaction product of the hydroconversion reaction unit is connected to the inlet of the separation and fractionation unit, and the separation and fractionation unit is provided with gas phase material outlet, kerosene component outlet and diesel component outlet.

Compared with the prior art, the present invention effectively solves the problems of metal deposition, chloride ion corrosion and hydrogenation reaction heat concentration in the process of hydrogenation of waste oil and fat; the raw material adaptability is strong, and all waste oil and fat raw materials can be used for bio-aviation fuel. Production; low-value methanol can be converted into high-value glycerin products, the effective utilization of waste oil resources can be realized, and the economic benefits of the process can be improved. The prepared aviation fuel does not contain sulfur, nitrogen, oxygen and aromatic hydrocarbons, and is a clean fuel; the continuous and industrialized production of waste grease is realized, which has practical significance.

Description of drawings

Fig. 1 is the schematic flow sheet of waste grease methylation unit provided by the invention

Fig. 2 is the schematic flow sheet of the hydrotreating reaction unit provided by the present invention

Fig. 3 is the schematic flow sheet of the hydroconversion reaction unit provided by the present invention

Detailed ways

The present invention is further described below with reference to the accompanying drawings, but the present invention is not limited thereby.

Fig. 1 is the schematic flow sheet of the waste grease methylation unit provided by the present invention, as shown in Fig. 1, waste grease 1, fresh methanol 2 and recycled methanol 5 enter the alcoholysis reactor 100 to react after mixing, boosting and heating The mixed material 3 after the alcoholysis reaction enters the rectifying tower 20, and the separated methanol 5 is recycled; The remaining mixed material 4 mainly contains methyl ester and glycerol, enters the thick methyl ester glycerin sedimentation separator 30, and the thick methyl ester 7 It leaves from the upper part of the separator 30 and enters the crude methyl ester flash vessel 40, and the crude glycerol 6 leaves from the lower part of the separator 30 for further refining. The crude methyl ester 7 is flashed in the crude methyl ester flash vessel 40 to obtain refined methyl ester 8 and heavy fat 9, and the remaining heavy fat 9 can be used as fuel instead of heavy oil. The refined methyl ester 8 enters the hydrotreating reaction unit.

Fig. 2 is a schematic flow diagram of a hydrotreating reaction unit provided by the present invention, as shown in Fig. 2, the refined methyl ester 21 from the waste oil and fat methylation unit is mixed with the liquid phase material 30 circulating in the hydrotreating product, and The mass ratio of the methyl ester to the circulating liquid phase material is 1:2 to 1:6. The sulfiding agent is supplemented, mixed with the new hydrogen 22 and the circulating hydrogen 26, and then heated and then entered into the fixed bed reactor 200 filled with the hydrotreating catalyst. The reacted material 23 enters the high-pressure vapor-liquid separator 50 after being cooled by heat exchange, and the product is divided into gas-phase material 25, water 24 and liquid hydrocarbons 27, and the gas-phase material 25 enters the gas treatment unit 60 to remove CO, CO ₂ , CH ₄ and other impurities are returned to the reactor inlet as circulating hydrogen 26. The generated water 24 is discharged from the bottom of the separator, the liquid hydrocarbons 27 enter the stripper 70 to further remove impurities such as water and H ₂ S, the gas 28 is discharged from the stripper 70, a part of the liquid material 29 enters the hydroconversion reaction unit, and the other A portion is mixed as recycle feed 30 with the feed to the hydrotreating reaction unit.

Fig. 3 is a schematic flow diagram of a hydroconversion reaction unit provided by the present invention. As shown in Fig. 3 , the liquid material 31 from the hydrotreating reaction unit is mixed with new hydrogen 32 and circulating hydrogen 33 and is heated into a hydroconversion Fixed bed reactor 300 for catalyst. The reacted material 34 enters the high-pressure vapor-liquid separator 80 after being cooled by heat exchange, the obtained vapor-phase material 33 is used as circulating hydrogen, and the obtained liquid-phase material 35 enters the fractionation tower 90 for separation to obtain liquefied gas 36, naphtha 37, Kerosene component 38 and diesel component 39.

The following examples will further illustrate the method provided by the present invention, but do not limit the present invention accordingly.

In the following examples, the freezing point, flash point and total acid value of kerosene components were measured according to the methods of GB/T2430, GB/T261 and GB/T12574, respectively. The mass yield of the kerosene component refers to the percentage of the mass of the prepared kerosene component to the mass of the waste oil and fat feedstock oil.

Preparation Example 1 Preparation of Hydrotreating Catalyst

Weigh 500 grams of pseudo-boehmite (produced by Changling Catalyst Factory), extrude it into a clover-shaped strip with a circumscribed circle diameter of 1.6 mm, and dry at 120° C. for 6 hours. Take 300 grams of it, and treat it for 6 hours at a temperature of 600 ° C under the condition of a one-step steam treatment method, the volume ratio of air to steam is 1:0.6, the gas flow rate is 1.0 standard cubic meters per kilogram. Hour, and the temperature is 600 ° C to obtain carrier S .

Weigh 100 grams of carrier S, impregnate it with 86 milliliters of an aqueous solution containing 5.8 grams of ammonium paramolybdate, 29.7 grams of nickel nitrate and 53.4 grams of ammonium metatungstate for 2 hours, dry at 120 ° C for 3 hours, and bake at 450 ° C for 4 hours to obtain hydrogenation. Treat Catalyst C. The weight contents of MoO ₃ , NiO and WO ₃ in the catalyst were 2.8%, 4.4% and 25.7%, respectively.

Preparation Comparative Example 1 Preparation of Hydrotreating Catalyst

Weigh 500 grams of pseudo-boehmite (produced by Changling Catalyst Factory), extrude it into a clover-shaped bar with a circumscribed circle diameter of 1.6 mm, dry it at 120°C for 6 hours, and then roast it in air at 600°C for 4 hours , the carrier DS was prepared.

Weigh 100 grams of carrier DS, impregnate it with 86 milliliters of an aqueous solution containing 5.8 grams of ammonium paramolybdate, 29.7 grams of nickel nitrate and 53.4 grams of ammonium metatungstate for 2 hours, dry at 120 ° C for 3 hours, and bake at 450 ° C for 4 hours to obtain hydrogenation. Process catalyst DC. The weight contents of MoO ₃ , NiO and WO ₃ in the catalyst were 2.6%, 4.5% and 25.8%, respectively.

Preparation Example 2 Preparation of Hydroconversion Catalyst

The catalyst was prepared according to the method of Example 1 in CN102205250A. A ZSM-22 molecular sieve (provided by Changling Catalyst Factory, with a silicon-to-aluminum ratio of 56) was evenly mixed with pseudoboehmite P1-1 and succulent powder, and an aqueous nitric acid solution was added, After thorough kneading, clover-shaped strips with a diameter of 1.3 mm were extruded on an extruder, dried at 120° C. for 4 hours, and then calcined in air at 600° C. for 2 hours to obtain a carrier. The support was saturated with a solution containing Pt(NH ₃ ) ₄ Cl ₂ , then dried at 110° C. for 4 hours, and calcined at 400° C. for 3 hours in an air atmosphere. The obtained catalyst was then reduced at a reduction temperature of 350° C., a reduction time of 4 hours, and a hydrogen pressure of 0.1 MPa. The catalyst after reduction is a hydroconversion catalyst, and the content of ZSM-22 in the catalyst is 50.2% by weight, the content of alumina is 49.0% by weight, and the content of Pt is 0.8% by weight.

Example 1

(1) Waste oil methyl esterification unit

Using waste oil from the catering industry as raw material, its quality indicators are as follows: density 0.91g·cm ^-3 , acid value 78mgKOH/g oil, sulfur 35μg/g, chlorine 29μg/g, mechanical impurities 0.12% by weight, metal ion content 11 μg/g, 92.7 wt % of saponifiable matter content, 6.3 wt % of gums, and 0.9 wt % of moisture. After the methanol and the above-mentioned raw materials were mixed in a ratio of 0.3:0.7, the temperature was increased and pressurized, the temperature was increased to 260 ° C, and the pressure was increased to 6.5 MPa, and then entered the reactor, and the residence time was 1 hour. Depressurize and enter the methanol rectification tower with a theoretical plate number of 30, and control the temperature of the tower kettle to be 125°C, the top temperature of the tower to be 67°C, the tower kettle pressure to be 0.03MPa, the tower top pressure to be 0.005MPa, and the reflux ratio to be 1 to separate methanol. The methanol water content obtained by separation is 0.05%, which is recycled. The still liquid of the methanol rectifying tower enters the thick methyl ester glycerol sedimentation separator to carry out sedimentation and phase separation, and stays for 1 hour, the glycerol of the lower layer is extracted and purified, and the crude methyl ester of the upper layer enters the thick methyl ester flash column, and the absolute pressure of the tower is 0.7 kPa, purified methyl ester and heavy oil were separated. The content of fatty acid methyl ester in refined methyl ester is 97%, the acid value is 1.7mgKOH/g oil, the kinematic viscosity (40°C) is 4.2mm ² /s, the sulfur content is 4μg/g, the Cl content is 1μg/g, and the metal ion content (in Na ⁺ g) 0.7 μg/g.

(2) Hydrotreating reaction unit

Mixing the refined methyl ester obtained from the waste oil and fat methylation unit with the circulating liquid phase material and H ₂ , and adding a sulfur-containing compound with a sulfur content of 1000 μg/g to the raw material, and contacting it with a hydrotreating catalyst; The ratio with the circulating liquid phase material is 1:3, and the hydrotreating catalyst is the catalyst prepared in Preparation Example 1. The reaction conditions of hydrotreating are: pressure 5.0MPa, average temperature 320℃, volume space velocity 1.0h ^-1 , and the volume ratio of hydrogen to reaction raw materials is 1000:1.

(3) Hydroconversion reaction unit

The resulting mixture of the liquid phase stream and hydrogen from the hydrotreating reaction unit is contacted with a hydroconversion catalyst. The hydroconversion catalyst is the catalyst prepared in Preparation Example 2. Hydrotreating conditions include: pressure of 5.0 MPa, average temperature of 330 °C, volumetric space velocity of 1.0 h ^-1 , and volume ratio of hydrogen to oil of 500:1.

(4) Product separation unit

The product after the hydroconversion reaction unit is fractionated to obtain a kerosene component at 150-280° C. The properties of the obtained kerosene component are shown in Table 1.

Example 2

(1) Waste oil methyl esterification unit

Using the waste oil and fat left after frying food as raw material, its quality indicators are as follows: density 0.91g·cm ^-3 , acid value 5mgKOH/g oil, sulfur 13μg/g, chlorine 7.8μg/g, mechanical impurities 0.22% by weight , the metal ion content is 5.9 μg/g, the saponifiable matter content is 95.3 wt %, the rubber compound is 3.9 wt %, and the moisture content is 0.7 wt %. After the methanol and the above-mentioned raw materials were mixed in a ratio of 0.4:0.6, the temperature was increased and pressurized, the temperature was increased to 280 ° C, and the pressure was increased to 8 MPa, and then entered the reactor, the residence time was 1.5 hours, and the temperature was lowered and lowered after leaving the reactor. Pressure into the methanol rectification column with a theoretical plate number of 26. Methanol separation was carried out by controlling the tower kettle temperature of 110°C, the tower top temperature of 65°C, the tower kettle pressure of 0.015MPa, the tower top pressure of 0.002MPa, and the reflux ratio of 1.3. The methanol water content obtained by separation is 0.046%, which is recycled. The still liquid of the methanol rectifying tower enters the thick methyl ester glycerol sedimentation separator to carry out sedimentation and phase separation, and stays for 1.5 hours, the glycerin of the lower layer is extracted and purified, and the crude methyl ester of the upper layer enters the thick methyl ester flash column, and the absolute pressure of the tower is 0.5 kPa, purified methyl ester and heavy oil were separated. Among them, the content of fatty acid methyl ester in refined methyl ester is 98%, the acid value is 0.6 mgKOH/g oil, the kinematic viscosity (40°C) is 4.0 mm ² /s, the sulfur content is 1 μg/g, the Cl content is none, the metal ion content (calculated as Na ⁺ ) 0.4 μg/g.

(2) Hydrotreating reaction unit

Mix the refined methyl ester obtained from the methyl esterification unit of waste oil, the recycled liquid phase material and _H2 , and add a sulfur-containing compound with a sulfur content of 1000 μg/g to the raw material, and contact with the hydrotreating catalyst; The ratio of the liquid feedstock oil is 1:2, and the hydrotreating catalyst is the catalyst prepared in Preparation Example 1. The reaction conditions of hydrotreating are: pressure 5.0MPa, average temperature 330℃, volume space velocity 2.0h ^-1 , and the volume ratio of hydrogen to reaction raw materials is 1000:1.

(3) Hydroconversion reaction unit

A mixture of the liquid phase feed of the hydrotreating reaction unit and hydrogen is contacted with a hydroconversion catalyst. The hydroconversion catalyst is the catalyst prepared in Preparation Example 2. The hydrotreating conditions included: the pressure was 5.0 MPa, the average temperature was 340°C, the volumetric space velocity was 1.5h ^-1 , and the volume ratio of hydrogen to oil was 500:1.

(4) Product separation unit

The product of the hydroconversion reaction unit is fractionated to obtain a kerosene component at 150-280° C. The properties of the obtained kerosene component are shown in Table 1.

Example 3

(1) Methyl esterification of waste oils and fats

The acidified soybean oil produced by acidification of oil legs and soap legs from soybean oil refining is used as raw materials, and its quality indicators are as follows: density 0.90g·cm ^-3 , acid value 139mgKOH/g oil, sulfur 7μg/g, chlorine 1.4 μg/g, 0.37% by weight of mechanical impurities, 255.6 μg/g of metal ion content, 93.7% by weight of saponifiable matter content, 5.1% by weight of glue, and 1.1% by weight of moisture. After the methanol and the above-mentioned raw materials were mixed in a ratio of 0.27:0.73, the temperature was increased and pressurized, the temperature was increased to 250 ° C, and the pressure was increased to 6 MPa, and then entered the reactor, and the residence time was 1 hour. Pressure into the methanol rectification column with a theoretical plate number of 32. Methanol separation was carried out by controlling the column temperature of 105 °C, the top temperature of 67 °C, the column pressure of 0.010 MPa, the column top pressure of 0.001 MPa, and the reflux ratio of 0.9. The methanol water content obtained by separation is 0.066%, which is recycled. The still liquid of the methanol rectifying tower enters the crude methyl ester glycerin sedimentation separator to carry out sedimentation and phase separation, and stays for 1.0 hour, the glycerin of the lower layer is extracted and purified, and the crude methyl ester of the upper layer enters the crude methyl ester flash tower, and the absolute pressure of the tower is 0.8 kPa, purified methyl ester and heavy oil were separated. Among them, the content of fatty acid methyl ester in refined methyl ester is 99%, the acid value is 1.9mgKOH/g oil, the kinematic viscosity (40°C) is 4.1mm ² /s, the content of sulfur and Cl is no, and the content of metal ions (calculated as Na ⁺ ) is 3.8μg /g.

(2) Hydrotreating reaction unit

Mix the refined methyl ester obtained from the methyl esterification unit of waste oil, the recycled liquid phase material and _H2 , and add a sulfur-containing compound with a sulfur content of 1000 μg/g to the raw material, and contact with the hydrotreating catalyst; The ratio of the liquid phase materials is 1:4, and the hydrotreating catalyst is the catalyst prepared in Preparation Example 1. The reaction conditions of hydrotreating are: pressure 5.0MPa, average temperature 320℃, volume space velocity 1.0h ^-1 , and the volume ratio of hydrogen to reaction raw materials is 1000:1.

(3) Hydroconversion reaction unit

The liquid phase feed of the hydrotreating reaction unit and the hydrogen mixture are contacted with a hydroconversion catalyst. The hydroconversion catalyst is the catalyst prepared in Preparation Example 2. Hydrotreating conditions include: pressure of 5.0 MPa, average temperature of 330 °C, volumetric space velocity of 1.0 h ^-1 , and volume ratio of hydrogen to oil of 500:1.

(4) Product separation unit

The kerosene component at 150-280° C. is obtained by fractional distillation of the product after the aforementioned hydroconversion reaction unit, and the properties of the obtained kerosene component are shown in Table 1.

Example 4

(1) Waste oil methyl esterification unit

Using acidified oil from palm oil refining as raw material, its quality indicators are as follows: density 0.89g·cm ^-3 , acid value 151mgKOH/g oil, sulfur 12μg/g, chlorine 23.4μg/g, mechanical impurities 0.41% by weight, The metal ion content was 107.3 μg/g, the saponifiable matter content was 94.1 wt %, the rubber compound was 4.4 wt %, and the moisture content was 1.4 wt %. After the methanol and the above-mentioned raw materials were mixed in a ratio of 0.5:0.5, the temperature was increased and pressurized, the temperature was increased to 270 ° C, and the pressure was increased to 7 MPa, and then entered the reactor, the residence time was 1 hour, and the temperature was lowered and lowered after leaving the reactor. Pressure into the methanol rectification column with a theoretical plate number of 36. Methanol separation was carried out by controlling the column temperature of 125°C, the top temperature of 69°C, the column pressure of 0.022MPa, the top pressure of 0.0015MPa, and the reflux ratio of 1.1. The methanol water content obtained by separation is 0.035%, which is recycled. The still liquid of the methanol rectifying tower enters the thick methyl ester glycerin sedimentation separator to carry out sedimentation and phase separation, stays for 1.0 hour, the glycerol in the lower layer is extracted and purified, and the crude methyl ester of the upper layer enters the thick methyl ester flash column, and the absolute pressure of the tower is 0.6 kPa, purified methyl ester and heavy oil were separated. Among them, the content of fatty acid methyl ester in refined methyl ester is 97.5%, the acid value is 1.4mgKOH/g oil, the kinematic viscosity (40°C) is 4.0mm ² /s, the content of sulfur and Cl is no, and the content of metal ions (calculated as Na ⁺ ) is 2.3μg /g.

(2) Hydrotreating reaction unit

Mix the refined methyl ester obtained from the methyl esterification unit of waste oil, the circulating liquid phase material, and H ₂ , and add a sulfur-containing compound with a sulfur content of 1000 μg/g to the raw material, and contact with the hydrotreating catalyst; The ratio of the liquid phase materials is 1:3, and the hydrotreating catalyst is the catalyst prepared in Preparation Example 1. The reaction conditions of hydrotreating are: pressure 5.0MPa, average temperature 320℃, volume space velocity 1.0h ^-1 , and the volume ratio of hydrogen to reaction raw materials is 1000:1.

(3) Hydroconversion reaction unit

A mixture of the liquid phase feed of the hydrotreating reaction unit and hydrogen is contacted with a hydroconversion catalyst. The hydroconversion catalyst is the catalyst prepared in Preparation Example 2. Hydrotreating conditions include: pressure of 5.0 MPa, average temperature of 330 °C, volumetric space velocity of 1.0 h ^-1 , and volume ratio of hydrogen to oil of 500:1.

(4) Product separation unit

The kerosene component at 150-280° C. is obtained by fractional distillation of the product after the aforementioned hydroconversion reaction unit, and the properties of the obtained kerosene component are shown in Table 1.

Table 1 Partial properties of kerosene components

It can be seen from the results in Table 1 that the kerosene component prepared by the method of the present invention meets the standard of synthetic paraffin kerosene derived from esters and fatty acids in ASTM D7566, and can be used as an aviation fuel component.

Comparative Example 1 Hydrotreating Catalyst Stability Comparison

The refined methyl ester obtained from the waste oil and fat methylation unit in Example ₁ is mixed with the circulating liquid phase material and H , and a sulfur-containing compound with a sulfur content of 1000 μg/g is added to the raw material, which is contacted with a hydrotreating catalyst; The ratio of refined methyl ester to the circulating liquid phase material is 1:3, and the hydrotreating catalysts are the catalyst C prepared in Preparation Example 1 and the catalyst DC prepared in Comparative Preparation Example 1. The reaction conditions of hydrotreating are: pressure 5.0MPa, average temperature 320℃, volume space velocity 2.0h ^-1 , and the volume ratio of hydrogen to reaction raw materials is 1000:1. The hydrodeoxygenation activity data after stable operation for a period of time are shown in Table 2.

The hydrodeoxygenation activity refers to (the oxygen content of the feedstock - the oxygen content of the liquid hydrocarbon product)/the oxygen content of the feedstock*100%

Table 2 Relative hydrodeoxygenation activities of hydrotreating catalysts at different operating times

As can be seen from the data in Table 2, according to the method provided by the present invention, the carrier of the used hydrotreating catalyst is treated with steam without calcination, which can significantly stabilize the properties of the carrier and avoid the water generated during the hydrotreating reaction process. Effects on hydrotreating catalysts.

Claims (21)

1. A method for producing aviation fuel components from waste grease, comprising the steps of: (1) waste oil methyl esterification unit, waste oil and methanol carry out alcoholysis reaction after mixing, boosting and heating to obtain crude glycerol and crude methyl ester, and crude methyl ester is flashed to obtain refined methyl ester; waste grease methyl ester The operating conditions of the chemical unit are as follows: the temperature of the alcoholysis reaction between waste oil and methanol is 180-320°C, the reaction pressure is 4-10MPa, the mass ratio of methanol to oil is 0.2-1:1, and the reaction time is 30-120min; (2) hydrotreating reaction unit, the refined methyl ester obtained in step (1) is contacted with a hydrotreating catalyst in the presence of hydrogen, and a deoxygenation reaction is carried out under hydrotreating conditions to obtain a hydrotreating product; Described hydrotreating catalyst comprises alumina carrier and hydrogenation active component supported on this carrier, described hydrogenation active component at least one is selected from VIII group and at least one is selected from VIB group metal group. In the preparation process, the alumina carrier includes the step of being treated with steam; (3) hydroconversion reaction unit, the obtained hydroprocessing product of step (2) is contacted with a hydroconversion catalyst in the presence of hydrogen, and a selective cracking reaction is carried out under hydroconversion conditions to obtain hydroconversion product; (4) Separation and fractionation unit, after separation and fractionation of the generated oil obtained by hydroconversion in step (3), kerosene components and diesel components are obtained. 2 . The method according to claim 1 , wherein the waste oil and fat are oil and fat wastes that are not suitable for consumption and are produced in animal and vegetable oil processing and edible consumption. 3 . 3. according to the described method of claim 1, it is characterized in that, the operating condition of waste oil and fat methyl esterification unit is: the temperature that waste oil and methanol generate alcoholysis reaction is 220～300 ℃, and reaction pressure is 5～8MPa, methanol The mass ratio to grease is 0.3～0.7:1; the reaction time is 60～90min. 4. according to the method described in claim 1, it is characterized in that, in the waste oil methyl esterification unit of step (1), the mixed material after the alcoholysis reaction enters rectifying tower, adopts the method for rectifying to extract methanol, rectifying The distillation column is a packed column or a tray column. 5. according to the method described in claim 1 or 4, it is characterized in that, in the waste oil and fat methyl esterification unit of step (1), set thick methyl ester glycerol sedimentation separator and thick methyl ester flash vessel, alcoholysis reaction The latter mixture material is separated from methanol and then enters into the crude methyl ester glycerol sedimentation separator. The separator operates continuously. The operating conditions are as follows: the temperature of the material is kept at 40-80 °C, and the residence time is 0.5 h to 3 h; after the sedimentation is completed, the crude methyl ester from The upper part of the separator leaves into the crude methyl ester flash vessel, and the crude glycerin leaves from the lower part of the separator; the crude methyl ester is flashed to obtain refined methyl ester, and the crude methyl ester flash vessel is a flash tank or a flash tower. 6. The method according to claim 5, characterized in that, in the waste grease methylation unit of step (1), the separator operates continuously, and the operating conditions are: the temperature of the material is maintained at 50～70°C; the residence time is 1 ~2h. 7. The method according to claim 5, wherein the crude methyl ester flash container is a flash tank or a flash tower, and the operating conditions of the flash tower are: temperature 220～350 ℃, pressure 2～0.3kPa. 8. according to the described method of claim 1 or 5, it is characterized in that, in described refined methyl ester, fatty acid methyl ester content is more than 95%, sulfur content is not more than 10 μg/g, chlorine content is not more than 1 μg/g, various metal The sum of the ion content is not more than 2μg/g. 9 . The method according to claim 1 , wherein the reaction conditions of the hydrotreating reaction unit are: the reaction temperature is 200～400° C., the hydrogen partial pressure is 1.0～10.0MPa, and the liquid hourly volume space velocity is 0.5～400°C. 10 . 10.0h ^-1 , the volume ratio of hydrogen to oil is 500～1500Nm ³ /m ³ . 10. according to the method for claim 1, it is characterised in that the liquid phase material part in the hydroprocessing product is recycled to the hydroprocessing reaction unit inlet, and the mass ratio of the refined methyl ester and the circulating liquid phase material is 1:2 ~1:6. 11. The method according to claim 1, wherein the hydrotreating catalyst preparation step comprises: (1) Mixing hydrated alumina and drying; (2) carrying out water vapor treatment to obtain a carrier; (3) The carrier obtained in step (2) is immersed in the prepared aqueous solution containing hydrogenation active components, and then dried and roasted to obtain a hydrogenation catalyst. 12. The method according to claim 11, wherein the hydrated alumina is pseudoboehmite. 13. The method according to claim 1 or 11, wherein the conditions of the water vapor treatment step include: a temperature of 450-750° C., a time of 4-8 hours, and a water-vapor flow rate of 0.5-5.0 standard cubic meters per kilogram of carrier ·Hour. 14. The method according to claim 11, characterized in that, the conditions for roasting in step (3) are: a temperature of 400-650° C. and a time of 2-6 hours. 15. The method according to claim 1 or 11, wherein in the hydrogenation active components of the hydroprocessing catalyst, the metal components of group VIII are cobalt and/or nickel, and the metal components of group VIB are Molybdenum and/or tungsten, calculated as oxide and based on catalyst, the content of the VIII group metal component is 1-10 wt %, and the content of the VIB group metal component is 10-45 wt %. 16. The method according to claim 1, wherein the reaction conditions in the hydroconversion reaction unit are: reaction temperature 200-500°C, hydrogen partial pressure 1.0-10.0Mpa, liquid hourly volume space velocity 0.5-5.0h ^-1 , the volume ratio of hydrogen to oil is 300～1200Nm ³ /m ³ . 17. The method of claim 1, wherein the hydroconversion catalyst comprises a molecular sieve with a one-dimensional mesoporous structure, a heat-resistant inorganic oxide matrix and a hydrogenation metal component. 18. The method according to claim 17, wherein, based on the total amount of hydroconversion catalysts, the content of the one-dimensional mesoporous molecular sieve is 20-80 wt %, and the alumina content is 15-75 wt % %, in terms of oxides, the content of hydrogenation metal components is 0.2 to 5% by weight, and the sum of the content of the above components is 100%. 19. The method according to claim 17 or 18, wherein the hydrogenation metal component is selected from one of cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, molybdenum and tungsten or several. 20. The method according to claim 17 or 18, wherein the one-dimensional mesoporous molecule is selected from ZSM-22, Nu-10, Thete-1, ISI-1, ZSM-23, SAPO-11, One or more of SAPO-31 and SAPO-41. 21. A system for producing aviation fuel components from waste grease, comprising: (1) waste oil methyl esterification unit, set up alcoholysis reactor, rectifying tower, thick methyl ester glycerol sedimentation separation zone, thick methyl ester flash vessel, waste oil and methanol carry out alcoholysis reaction in alcoholysis reactor, The mixed material after the alcoholysis reaction enters the rectifying tower to extract methanol; the mixed material after separating the methanol enters the crude methyl ester glycerin sedimentation separator, the upper part of the crude methyl methyl glycerin sedimentation separator is provided with a crude methyl ester extraction line, and the lower part is provided with a crude glycerin The extraction line, the crude methyl ester extraction line is connected with the inlet of the crude methyl ester flash container, and the crude methyl ester flash container is provided with a refined methyl ester extraction line and a heavy oil extraction line; (2) hydrotreating reaction unit, the hydrotreating reaction unit is provided with a hydrotreating reactor, wherein a hydrotreating catalyst is loaded, and the refined methyl ester extraction line from the waste oil and fat methylation unit is connected with the hydrotreating reactor inlet, The outlet of the hydrotreating reactor is connected to the inlet of the separation and fractionation unit. The separation and fractionation unit is provided with a gas phase material outlet and a liquid phase material outlet. The liquid phase material outlet is connected to the liquid phase material circulation line and the liquid phase material extraction line, and the liquid phase material circulation line is connected to The inlet of the hydrotreating reactor is connected; (3) hydroconversion reaction unit, the hydroconversion reaction unit is provided with a hydroconversion reactor, wherein a hydroconversion catalyst is loaded, and the liquid phase material draw-off line from the hydrotreating reaction unit is connected with the hydroconversion reactor inlet, adding The outlet of the hydroconversion reactor is connected with the extraction line of the hydroconversion reaction product; (4) Separation and fractionation unit, the extraction line of the hydroconversion reaction product of the hydroconversion reaction unit is connected to the inlet of the separation and fractionation unit, and the separation and fractionation unit is provided with gas phase material outlet, kerosene component outlet and diesel component outlet.

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