Method for preparing unrefined SAF intermediate using polyols and the SAF intermediate prepared thereby
A method for preparing unrefined sustainable aviation fuel (SAF) includes: adding a catalyst to a reaction kettle, then adding a polyol solution to fill the reaction kettle; sealing the reaction kettle, introducing gas into the reaction kettle to discharge excess polyol solution and replace the atmosphere in the reaction kettle; stirring thoroughly to mix the catalyst uniformly with the polyol solution; then continuing to introduce gas into the reaction kettle to increase the internal pressure; subsequently conducting the reaction, and after the reaction is completed, collecting the upper liquid product to obtain unrefined SAF. The invention employs a one-pot method to prepare unrefined SAF, utilizing the interaction between polyols and solvents to provide H 2 for the system, thereby achieving carbon chain growth and hydrodeoxygenation without the need for high-pressure H 2 . The synthesis protocol demonstrates operational simplicity, employs mild reaction conditions, and utilizes commercially accessible feedstock with favorable cost-efficiency profiles.
1 . A method for preparing unrefined Sustainable Aviation Fuel (SAF) using polyols, comprising the following steps:
adding a catalyst to a reaction kettle, then adding a polyol solution to fill the reaction kettle; sealing the reaction kettle, introducing a gas into the reaction kettle to discharge excess polyol solution and replace the atmosphere in the reaction kettle; stirring thoroughly to mix the catalyst uniformly with the polyol solution; then continuing to introduce the gas into the reaction kettle to increase an internal pressure; subsequently conducting a reaction, and after the reaction is completed, collecting an upper liquid product to obtain unrefined SAF;
wherein the polyol is selected from the group consisting of glycerol, ethylene glycol, sorbitol, mannitol and xylitol; a solvent of the polyol solution is selected from the group consisting of water, ethanol and methanol, wherein the mass ratio of the polyol to the solvent is selected from (3-10):(0-5);
wherein the gas is selected from the group consisting of helium, nitrogen, and carbon dioxide;
wherein the catalyst is selected from the group consisting of a monometallic metal-organic frameworks (MOF) catalyst and a bimetallic MOF catalyst;
wherein the monometallic MOF catalyst is synthesized through a sequential protocol: the metal A salt solution is mixed with the ligand solution, stirred thoroughly, and subjected to a hydrothermal reaction; the resulting product is then washed, dried, and calcined to obtain monometallic MOF catalyst; and the metal salt in the mentioned metal salt solution A is selected from the group consisting of the salts of Mn, Cr, Fe, Co, Ni, Cu, and Zn;
wherein the bimetallic MOF catalyst is synthesized through a sequential protocol: the monometallic MOF catalyst is added to metal salt solution B and allowed to react, yielding a metal-doped monometallic MOF catalyst; the doped catalyst is then washed, dried, and calcined to obtain a bimetallic MOF catalyst; the metal salt in the described metal salt solution B is selected from salts of Mn, Cr, Fe, Co, Ni, Cu, or Zn, wherein the metal used in the metal salt solution B differs from the metal species in the monometallic MOF catalyst; and
wherein the unrefined SAF comprises 2,5-hexanedione, 2-acetylfuran, 2,4-dimethyl-2-(hydroxymethyl)-1,3-dioxolane, 2-oxooctanoic acid, (allyloxymethyl) oxirane, glycerol formal, 2,6-bis(hydroxymethyl)-1,4-dioxane, and ethylene glycol diglycidyl ether.
2 . The method for preparing unrefined SAF using polyols according to claim 1 , the mass-to-volume ratio of the catalyst to the polyol solution is selected from (1-5):(20-50), g:mL.
3 . The method for preparing unrefined SAF using polyols according to claim 1 , wherein the stirring conditions are selected as: stirring at 400-1000 r/min for 20-120 min at 20-30° C.; the reaction conditions are selected as: reacting at 200-1000 r/min for 3-20 h at 160-300° C.
4 . The method for preparing unrefined SAF using polyols according to claim 1 , wherein an autoclave pressure is selected as 0.5-1 MPa.
5 . The unrefined SAF prepared by the method for preparing unrefined SAF using polyols according to claim 1 , the yield of C6-C16 products in the prepared unrefined SAF is greater than 44.67%.