36results about How to "Short reaction temperature" patented technology

The invention discloses modified Ca-Co-O system doped composite oxide of transition metals and the preparing method thereof, and relates to thermoelectric material and the preparing method thereof. The invention solves the problems of high reaction temperature, long reaction time and easy impurity production of the prior Ca-Co-O system preparing method. The general formula of the composite oxide is Ca3Co2-xMxO6 or Ca3-x-yMxNyCo4O9+Delta, wherein, M refers to Fe, Ni, Nd or Er, and N refers to Na or Bi. The method contains the following procedures: firstly, dissolving materials into deionized water according to the respective stoichiometric ratio of the molecular formula, mixing the water solution of raw materials uniformly, slowly injecting citric acid solution and performing ultrasonic oscillation to produce homogeneous sol; secondly, heating for dehydration with microwave to get wet sol; thirdly, drying the wet sol to get dry sol and allowing self-propagating combustion; fourthly, baking after grinding. Compared with the prior art, the invention has the advantages of short reaction time, low baking temperature and simple operation. The powder of the material of the invention has uniform particle distribution and high purity; the powder has flaky structure and the particle diameter is smaller than 200nm.

The invention discloses a high-efficiency environment-friendly preparation method of 2-hydroxyethylpyridine, which comprises the following steps: proportionally adding 2-methylpyridine and formaldehyde into a high-pressure autoclave, adding a solid superhigh acid catalyst, heating while stirring to react, quickly cooling the high-pressure autoclave, filtering out the solid superhigh acid catalyst, distilling the mixed solution under reduced pressure, and distilling off unreacted 2-methylpyridine, formaldehyde and water under the pressure of 10-100 mmHg to obtain the 2-hydroxyethylpyridine end product. Abundant experiments are performed to screen out the optimal proportion of the reactant raw material to the catalyst thereof; and abundant experiments are performed to screen out the optimum reaction temperature, reaction time and reaction pressure. The whole method has the advantages of reasonable technique, small environmental pollution, low reaction temperature, short reaction time, high reaction efficiency, low production cost, high yield and high purity of the prepared 2-hydroxyethylpyridine.

The invention discloses a preparation method of an 8-hydroxyquinoline iron organic dye photodegradation catalyst, and belongs to the field of metal-organic complexes. The method comprises the following steps: firstly, preparing a photodegradation catalyst reaction solution, dissolving ligands in N,N-dimethylformamide or methanol, dissolving an iron salt in methanol or N,N-dimethylformamide, mixingthe obtained two solutions, carrying out stirring at room temperature, heating the prepared reaction liquid to 60-80 DEG C for a reaction, slowly carrying out cooling to room temperature after the reaction is finished to obtain a brown black block crystal, then carrying out washing in methanol, and carrying out airing, so as to obtain the 8-hydroxyquinoline catalyst with catalytic activity. Themethod provided by the invention has simple operation, mild condition and low cost, and the efficiency is high when the catalyst is applied to organic dye photodegradation, so that the method providedby the invention has feasibility in industrial application.

The invention discloses a method for co-producing furaldehyde, cellulose and lignin by depolymerizing biomasses. According to the method, in a mixed solvent of water and acetone, depolymerization andseparation of the biomasses are catalyzed in a one-step manner under the synergistic effect of phosphoric acid and sulfuric acid, the reaction temperature of furaldehyde production is effectively reduced, the reaction time of furaldehyde production is effectively shortened, energy conservation and emission reduction are achieved, the production cost of furaldehyde products is greatly reduced, highyield of the furaldehyde products is achieved, lignin components and cellulose components in biomass raw materials are efficiently separated, the purity of cellulose in residues is high, the cellulose can serve as a commodity or a raw material to be reused, and the method solves the problems that according to an existing furaldehyde production process, reaction steps are more, reaction temperature is high, reaction time is long, yield is low, and components cannot be efficiently separated.

A method for preparing glucosamine hydrochloride is characterized in that the following steps are adopted: 1) chitin is processed by gas explosion expansion method: the chitin raw material is packed in an air explosion expansion tank, and the gas explosion expansion medium is injected into the gas explosion expansion medium. Use one of water vapor, water, ammonia water, and ethanol; instantly release the pressure in the gas explosion expansion tank, and spray the chitin raw material into the normal pressure container to obtain the chitin concentrate; 2) hydrochloric acid hydrolysis; 3 ) decolorization; 4) filtration; 5) concentrated crystallization; 6) secondary crystallization. Compared with the prior art, the present invention has the following advantages: 1) the chitin pretreated by the gas explosion puffing method is used as raw material, which has higher chemical activity and can obtain higher product yield; 2) in the hydrolysis process , almost no "coking" phenomenon; 3) GAH is extracted once in the process, and the preparation of GAH becomes simple; 4) Hydrochloric acid can be recycled to realize clean production of GAH.