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CN-121988351-A - Method for hydrodeoxygenation of grease

CN121988351ACN 121988351 ACN121988351 ACN 121988351ACN-121988351-A

Abstract

The invention relates to a method for hydrodeoxygenation of grease, which adopts molybdenum sulfide catalyst to hydrodeoxygenation of grease in solvent, can convert waste grease into n-alkane with 15-18 carbon atoms, and has oil yield up to 65% and conversion rate up to 100%.

Inventors

  • MA HUAIJUN
  • Gong shuxin
  • SONG HUAN
  • TIAN ZHIJIAN
  • QU WEI
  • HAN JIANQIANG
  • CHEN XIN

Assignees

  • 中国科学院大连化学物理研究所

Dates

Publication Date
20260508
Application Date
20241105

Claims (9)

  1. 1. A method for hydrodeoxygenation of grease is characterized in that, Which adopts molybdenum sulfide catalyst to carry out grease hydrodeoxygenation in solvent, The synthesis of the molybdenum sulfide catalyst comprises the following steps: (1.1) adding molybdenum isooctanoate having a molar ratio of molybdenum to sulfur of from 1:3 to 8 (preferably from 1:4 to 8, more preferably from 1:7 to 8), an aqueous solution of a sulfur precursor or a sulfur precursor and water to a hydrothermal kettle; (1.2) the hydrothermal kettle is subjected to constant temperature reaction at 180 ℃ for a specified time, and naturally cooled to room temperature (15-30 ℃); (1.3) carrying out solid-liquid separation on the mixture in the hydrothermal kettle; (1.4) washing and drying the solid to obtain the molybdenum sulfide catalyst.
  2. 2. The method of claim 1, wherein the sulfur precursor in step (1.1) comprises one or more of ammonium sulfide, thiourea and L-cysteine; the mass ratio of sulfur precursor to water is 1:12-15, preferably 1:13-15, more preferably 1:14-15.
  3. 3. A process according to claim 1 or 2, wherein the specified time in step (1.2) is in the range of 4 to 24 hours, preferably 8 to 16 hours, more preferably 12 to 16 hours.
  4. 4. A method according to claim 1, characterized in that: Catalytic hydrodeoxygenation of lipids using a molybdenum sulfide catalyst: (2.1) adding grease and a solvent into a high-pressure reaction kettle; (2.2) weighing the prepared molybdenum sulfide catalyst, and adding the catalyst into a high-pressure reaction kettle; (2.3) replacing the internal atmosphere of the reaction kettle with hydrogen, and then filling hydrogen; (2.4) heating the reaction kettle to the required temperature, stirring at constant temperature for reaction, and naturally cooling to room temperature (15-30 ℃) to obtain the product.
  5. 5. The method according to claim 1 or 4, wherein the amount of the oil in the step (2.1) is 5 to 10g and the amount of the solvent is 20 to 25g; the solvent is one or more than two of tridecane, tetrahydronaphthalene or decalin.
  6. 6. The process according to claim 4, wherein the hydrogen pressure in step (2.3) is 2-10MPa, preferably 8-10MPa, more preferably 9-10MPa.
  7. 7. The method according to claim 4, wherein the specified temperature in step (2.4) is 340-380 ℃, preferably 360-380 ℃.
  8. 8. The method according to claim 4, wherein the specified time in step (2.4) is 1 to 8 hours, preferably 2 to 6 hours, more preferably 4 to 5 hours.
  9. 9. The method according to claim 1 or 4, wherein the fat is one or more of waste fat (swill oil, frying oil, plant offal oil, waste animal fat) and animal fat or vegetable fat.

Description

Method for hydrodeoxygenation of grease Technical Field The invention belongs to the technical field of catalyst synthesis, and particularly relates to a preparation method of a molybdenum sulfide catalyst used for hydrodeoxygenation of waste oil and fat Background As a renewable energy source, green diesel has various advantages in terms of biodegradation, environmental protection, toxicity and the like. The main production mode is that the waste grease is subjected to hydrodeoxygenation. The waste oil and fat sources are extremely complex, and comprise swill oil, frying oil, plant leftover oil, waste animal oil and fat and the like, and the main components of the waste oil and fat are triglyceride and fatty acid. The main way of hydrodeoxygenation of waste grease at present is carried out by a supported single-precious metal or double-precious metal catalyst, which has poor toxicity resistance and high price. The method for hydrodeoxygenation by using the molybdenum sulfide catalyst can greatly reduce the cost of the catalyst and improve the performance and the toxicity resistance of the hydrodeoxygenation catalyst. Disclosure of Invention The invention aims to provide a preparation method of one or more molybdenum sulfide catalysts for hydrodeoxygenation of waste grease. The catalyst synthesized by the invention reaches the level of 50nm, has high dispersibility, can convert waste grease into n-alkane with 15-18 carbon atoms, and has the oil yield reaching 65% and the conversion rate reaching 100%. The invention provides a preparation method of a molybdenum sulfide catalyst for hydrodeoxygenation of waste oil, which comprises the following steps: (1) Preparation of molybdenum sulfide catalyst: (1.1) the weighed sulfur precursor was placed in a 100ml beaker, 25g of water was added and stirred for 10min, and transferred to a 100ml stainless steel hot pot equipped with a polytetrafluoroethylene liner; (1.2) weighing molybdenum iso-octoate, then placing the molybdenum iso-octoate into a hydrothermal kettle, and screwing a cover of the hydrothermal kettle by using a wrench; (1.3) putting the hydrothermal kettle into a 180 ℃ oven, and taking out after constant temperature for a specified time; (1.4) after the hydrothermal kettle is opened, the mixture is filtered under reduced pressure through a buchner funnel; (1.5) washing the solid materials on the Buchner funnel three times with water and absolute ethyl alcohol, filtering again under reduced pressure, and pumping out the liquid in the solid materials; (1.6) taking out the solid on the Buchner funnel, transferring the solid to a 9cm culture dish, drying the solid in a vacuum drying oven at 70 ℃ for 12 hours, and taking out the solid to obtain the molybdenum sulfide catalyst; (2) The catalyst prepared by the method is applied to the hydrogenation degradation of polypropylene on a slurry bed: (2.1) weighing 10g of waste grease and 20g of solvent, and adding the mixture into a 100ml Parr high-pressure reaction kettle; (2.2) weighing 0.1g of the molybdenum sulfide catalyst prepared above, and adding the catalyst into a 100ml Parr high-pressure reaction kettle; (2.3) after the reaction kettle is assembled, replacing 3 times by 1-1.5MPa of hydrogen, and then filling a certain amount of hydrogen; (2.4) heating the reaction kettle to a specified temperature at a heating rate of 10 ℃ per minute, stirring at a constant temperature for 2 hours, and naturally cooling to room temperature (below 30 ℃); (2.5) after the tail gas is discharged, opening the kettle body, and taking out and analyzing the liquid in the kettle. The indication that the sulfur precursor in (1.1) may be 30% ammonium sulfide solution, thiourea and L-cysteine; in this regard, when the sulfur precursor in (1.1) is an ammonium sulfide solution, water is additionally supplemented to be equal to the amount of water used for other sulfur precursors; The indication that the sulfur/molybdenum molar ratio of the sulfur precursor and the molybdenum precursor in (1.2) may be 3-8:1; the designation time in (1.3) is 4 to 24 hours; The point out that (1.3) the oven needs to be warmed to the specified temperature in advance; the teaching is that (1.4) buchner funnel filtration uses qualitative filter paper; The molybdenum sulfide catalyst is obtained after drying (1.6), and is required to be ground into powder by a mortar for use; The solvent in (2.1) may be tridecane, tetrahydronaphthalene or decalin; the waste grease in (2.1) may be 5-10g; The solvent content in (2.1) may be 20-25g; The hydrogen pressure in (2.1) is 2 to 10MPa; The designation temperature in (2.4) is 340-380 ℃; the stirring rate in (2.4) was 300rpm; it is pointed out that (2.5) the sampling requires the use of a microporous filter membrane to filter out the solids in the sampler The invention has the beneficial effects that: 1. the nano molybdenum sulfide catalyst prepared by the hydrothermal method has the advantages of small size of the sheet