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CN-121972154-A - Method for preparing 1, 3-propylene glycol by hydrogenolysis of glycerol

CN121972154ACN 121972154 ACN121972154 ACN 121972154ACN-121972154-A

Abstract

The patent relates to a method for preparing 1, 3-propylene glycol by hydrogenolysis of glycerol. The patent prepares the multi-active-component catalyst by using a cylindrical Al 2 O 3 carrier, can lead the glycerol aqueous solution to have high conversion rate and high selectivity to hydrogenolyze to generate the target product 1, 3-propanediol under certain hydrogen pressure and temperature, and has good structural stability and can be reused.

Inventors

  • LIU FEI
  • WU HEJIN
  • WANG AIQIN
  • ZHENG MINGYUAN
  • CUI JIALIANG
  • ZHANG TAO

Assignees

  • 中国科学院大连化学物理研究所

Dates

Publication Date
20260505
Application Date
20251125

Claims (8)

  1. 1. A method for preparing 1, 3-propylene glycol by hydrogenolysis of glycerin is characterized in that a catalyst is adopted as a supported catalyst, a carrier is formed cylindrical alumina (Al 2 O 3 ), an active component is platinum metal (Pt) and an auxiliary agent thereof, the auxiliary agent is denoted as A and contains one or more than two of W, mo, fe, al, la, ce, sn, zr, zn, mn, nd and Ta, wherein the metal platinum loading is 0.1-10% by mass of Al 2 O 3 , the auxiliary agent A metal loading is 0.01-15% by mass of Al 2 O 3 , and the obtained catalyst is denoted as Pt/AOx/Al 2 O 3 ; the cylindrical Al 2 O 3 carrier is prepared and obtained based on a micelle template-guided precipitation method; The preparation method comprises the following steps: 1) Uniformly mixing aluminate solution with the concentration of 0.5-3.0mol/L with sodium salt of alkyl carboxylic acid serving as a template agent, and fully dissolving the template agent under the stirring condition at the temperature of 25-85 ℃ to form micelle solution; the aluminate mass is 5-50g according to the Al 2 O 3 ; 2) Adding carbonate solution with the concentration of 0.5-2.5mol/L and the volume of 35-500mL into the micelle solution at the rate of 1-5mL/min, generating aluminum hydroxide precursor sediment through the guiding action of a micelle template, aging the aluminum hydroxide precursor sediment for 2-12 hours at the temperature of 25-85 ℃, washing the aged aluminum hydroxide with ammonium salt solution with the concentration of 0.1-2.0mol/L and the volume of 4-30L by an ion exchange method until the electric conductivity of an eluate is stable at 35-45 mu S/cm within 5-20 min to obtain an aluminum hydroxide filter cake, adding sesbania powder into the aluminum hydroxide filter cake as an extrusion aid, adjusting the mass of the sesbania powder to 1-3 percent based on the mass of the aluminum hydroxide filter cake, adding deionized water to adjust the humidity, fully kneading the total water content of the mixture material at 30-50wt%, aging for 0.5-5 hours through a screw extruder, and obtaining cylindrical aluminum hydroxide wet strips with the die aperture of 1-5mm and cutting length of 4-8 mm; 3) Drying the cylindrical aluminum hydroxide wet strip in the shade for 8-36 hours at room temperature, drying for 2-8 hours at 80-120 ℃, transferring into a muffle furnace, and roasting for 2-5 hours at a high temperature of 400-800 ℃ to obtain the cylindrical Al 2 O 3 carrier.
  2. 2. The method of claim 1, wherein a cylindrical Al 2 O 3 carrier is obtained, the pore diameter is distributed at 1-12nm, the average pore diameter is 2-4nm, and the specific surface area is 150-400m 2 /g; AOx is metal oxide corresponding to the assistant A, and x ranges from 1 to 6.
  3. 3. The method of claim 1, wherein the alkyl carboxylic acid sodium salt has a carbon chain length of 10-18, and comprises one or more of sodium caprate, sodium undecanoate, sodium laurate, sodium tridecanoate, sodium myristate, sodium stearate, sodium pentadecanoate, sodium palmitate, sodium isotridecanoate, sodium 2-hexylcaprate and sodium isostearate, wherein the molar ratio of sodium alkyl carboxylic acid sodium salt to aluminate (template/AlO 2 - ) used as the template is 0.01-0.50 in terms of aluminate (AlO 2 - ).
  4. 4. The support of claim 1, wherein the aluminate solution comprises one or a combination of two or more of sodium aluminate solution, potassium aluminate solution, and ammonium aluminate solution, the aluminates being expressed as aluminate radicals (AlO 2 - ).
  5. 5. The method of claim 1, wherein the selected carbonate solution comprises one or a combination of two or more of sodium bicarbonate solution, ammonium carbonate solution, and ammonium bicarbonate solution, and wherein the molar ratio of carbonate added to aluminate (CO 3 2- /AlO 2 - ) is 1.0 to 1.5, calculated as aluminate (AlO 2 - ).
  6. 6. The method of claim 1, wherein the ammonium salt solution used for washing after aging comprises one or a combination of two or more of ammonium methyl formate, ammonium carbonate, ammonium bicarbonate and ammonium acetate, and the concentration of the ammonium salt solution is 0.1-2.0mol/L.
  7. 7. The method of claim 1, wherein the platinum precursor and the auxiliary agent precursor are simultaneously or respectively loaded on a cylindrical carrier Al 2 O 3 in sequence by adopting a wet impregnation method, the platinum precursor is one or two or more of chloroplatinic acid, platinum nitrate, platinum acetate and platinum acetylacetonate, the auxiliary agent A precursor is one or two or more of chloride, nitrate, phosphate, acetylacetonate and acetate of W, mo, fe, al, la, ce, sn, zr, zn, mn, nd and Ta, the impregnation is carried out for 20-50 hours, the impregnation is carried out at room temperature for 20-50 hours, the impregnation is carried out at a high temperature in a muffle furnace, the roasting temperature is 200-400 ℃, and the roasting time is 1-3 hours, so that the catalyst Pt/AOx/Al 2 O 3 is obtained.
  8. 8. The method of claim 1, wherein a fixed bed reactor is adopted, the reaction raw material is glycerin water solution, the mass concentration is 10-90%, the glycerin liquid airspeed is 0.06-1.5h -1 , the hydrogen gas reaction pressure is 0.1-12MPa, the hydrogen gas airspeed is 50-200h -1 , and the reaction temperature is 100-250 ℃.

Description

Method for preparing 1, 3-propylene glycol by hydrogenolysis of glycerol Technical Field The invention relates to a multi-active component catalyst taking cylindrical alumina as a carrier for preparing 1, 3-propanediol by hydrogenolysis of glycerin Technical Field Biodiesel production is increasingly prospering to benefit the world, ensuring a greener fuel supply, reducing reliance on non-renewable fossil fuels, but also has the disadvantage that rapid development of biodiesel brings about a large amount of glycerol by-product, and low cost and excess supply of glycerol requires the biodiesel industry to find value-added conversion pathways. For this reason, various products have been proposed for converting glycerol into valuable products, such as the hydrogenolysis of glycerol to 1, 3-propanediol (1, 3-PDO). The 1, 3-propanediol has wide industrial application prospect, and has application in various fields including cosmetology, clinic and pharmaceutical industry, the hydrogenolysis synthesis of glycerol for preparing 1,3-PDO has good environmental benefit and economic benefit, but how to activate secondary hydroxyl in glycerol to inhibit the generation of 1, 2-propanediol (1, 2-PDO) is still a difficult problem, and besides the selective competition between 1,3-PDO and 1,2-PDO, the two can be deeply hydrogenated for generating n-propanol and isopropanol, and in order to selectively catalyze the generation of 1,3-PDO and inhibit side reaction, the precise construction of a catalyst structure and the regulation of reaction conditions are critical. Disclosure of Invention The invention provides a multi-active-component catalyst taking cylindrical alumina as a carrier, which is used for preparing 1, 3-propanediol by hydrogenolysis of glycerol. Compared with the prior art, the technology of the invention effectively improves the conversion rate of glycerin and the selectivity of 1, 3-propanediol, and the multi-active component catalyst taking cylindrical alumina as a carrier has good structural stability and can be reused. The invention provides a method for preparing 1, 3-propanediol by hydrogenolysis of glycerol. Preparing a multi-active-component catalyst by using a cylindrical Al 2O3 carrier, wherein the cylindrical Al 2O3 carrier is prepared by a micelle template-oriented precipitation method; the preparation process includes 1) mixing aluminate solution of 0.5-3.0mol/L concentration and alkyl carboxylic acid sodium salt as template agent, the mass of aluminate is 5-50g calculated by Al 2O3, the reaction temperature is 25-85 ℃, the template agent is fully dissolved and forms micelle solution under stirring condition, 2) adding carbonate solution of 0.5-2.5mol/L concentration and volume of 35-500mL into the micelle solution at a slow rate of 1-5mL/min, generating aluminum hydroxide precursor precipitate by guiding action of micelle template, aging the aluminum hydroxide precursor precipitate at 25-85 ℃ for 2-12 hours by ion exchange method, washing the aged aluminum hydroxide with ammonium salt solution of 0.1-2.0mol/L concentration and volume of 4-30L until the conductivity of eluate is 35-45 mu S/cm to obtain aluminum hydroxide filter cake, adding sesbania powder as extrusion aid agent into the aluminum hydroxide filter cake, the mass of sesbania powder is 1-3% based on the mass of aluminum hydroxide, adding deionized water to adjust the humidity of the filter cake, the total water content of the filter cake is 30-5 mm, the mixture is cut by a cylindrical mixer at a temperature of 3-5 mm to 3 mm, the cylindrical kneading machine is cut at a bore diameter of 3-5-3 mm, the cylindrical kneading machine is cut at a wet-8 ℃ for 1-8 mm, the cylindrical kneading machine is fully dried for 3-8 mm, the cylindrical rod is cut at a wet-8 mm is dried, the cylindrical rod is cut at a time of 3-8 mm is completely after the cylindrical kneading machine is dried, then transferring the mixture into a muffle furnace, and roasting the mixture at a high temperature of 400-800 ℃ for 2-5 hours to obtain the cylindrical Al 2O3 carrier, wherein the pore diameter is distributed at 1-12nm, the average pore diameter is 2-4nm, and the specific surface area is 150-400m 2/g. The cylindrical Al 2O3 carrier is used for preparing a multi-active-component catalyst, wherein the metal platinum loading is 0.1-10% by mass of Al 2O3, the auxiliary agent is A, the auxiliary agent A is one or more of W, mo, fe, al, la, ce, sn, zr, zn, mn, nd and Ta, the auxiliary agent metal loading is 0.01-15% by mass of Al 2O3, and the catalyst is obtained and marked as Pt/AOx/Al 2O3 (AOx is a metal oxide corresponding to the auxiliary agent A, and the x range is 1-6). In the cylindrical Al 2O3 carrier, the carbon chain length of the selected sodium alkyl carboxylate is 10-18, and the molar ratio of the sodium alkyl carboxylate used as a template agent to aluminate (template agent/AlO 2-) is preferably 0.01-0.50, more preferably 0.1-0.4, and the molar r