10results about How to "Shorten crystallization time" patented technology

The invention belongs to the technical field of anhydrous magnesium chloride production, and particularly relates to a preparation process of anhydrous magnesium chloride, which comprises the following steps: firstly, dissolving magnesium chloride hexahydrate in absolute ethyl alcohol to form a magnesium chloride ethanol aqueous solution, and then dehydrating the magnesium chloride ethanol aqueous solution by using a molecular sieve to obtain the magnesium chloride ethanol solution; carrying out secondary cooling, stirring crystallization, secondary solid-liquid separation and vacuum drying on the magnesium chloride ethanol solution to obtain high-purity anhydrous magnesium chloride; and recycling ethanol liquid obtained by solid-liquid separation and ethanol gas obtained by vacuum drying. The technical scheme provided by the invention is simple in process flow, low in energy consumption, low in equipment requirement, high in product yield and high in purity, and can be directly applied to the fields of electrolytic preparation of magnesium, catalyst carriers and the like.

The application relates to the field of carbon nanotube catalyst materials, and specifically discloses a catalyst and a preparation method thereof, an array type carbon nanotube and a preparation method thereof. A catalyst is formed into a sheet-shaped nanocrystalline grain, and the sheet-shaped nanocrystalline grain comprises at least one kind of microwave active metal ion. The preparation method of the catalyst comprises the following steps: S1, microwave-assisted reaction; S2, standing and aging; and S3, calcination treatment. An array type carbon nanotube is prepared by catalysis of the catalyst, the array type carbon nanotube has a plurality of unit carbon nanotube bundles, the unit carbon nanotube bundle comprises a plurality of carbon nanotubes which are intertwined and have a tube length greater than 1 mu m, and the tube diameter of the unit carbon nanotube bundle is 0.2-2 mu m. The carbon nanotube prepared by catalysis of the catalyst has a consistent length-diameter ratio, good orientation and high purity, so that the excellent performance of the carbon nanotube can be brought into play.

This invention relates to the field of all-silica molecular sieve preparation technology, and discloses a method for preparing an MFI topological structure all-silica molecular sieve, the MFI topological structure all-silica molecular sieve and its application, comprising: (1) mixing molecular sieve mother liquor, organosilicate, organic template agent and KOH to obtain a colloidal mixture; (2) subjecting the colloidal mixture to a crystallization reaction; (3) performing solid-liquid separation on the crystallization product obtained in step (2) to obtain a wet molecular sieve and a crystallization mother liquor; drying and calcining the wet molecular sieve to obtain an MFI topological structure all-silica molecular sieve; (4) optionally concentrating the crystallization mother liquor, and then returning to step (1) to provide the molecular sieve mother liquor. This method can obtain highly crystallized, fine-particle all-silica-1 molecular sieves, reduce the raw material cost of molecular sieve synthesis, and improve the economics of the new gas-phase rearrangement process technology.

This application provides a method for purifying crude dihydroxyethyl terephthalate (BHET), a method for preparing BHET, and a BHET product. The method includes: mixing crude BHET with a solvent to obtain a first mixture; wherein the solvent includes a first solvent and a second solvent; subjecting the first mixture to stepwise cooling, during which the BHET in the first mixture crystallizes to obtain purified BHET. This method optimizes crystallization kinetics, shortens crystallization time, reduces solution viscosity, and thus improves solid-liquid separation performance, ultimately obtaining a high-purity, uniformly sized BHET product.

This invention provides a method for producing lubricating oil base oil from heavy feedstock and the resulting lubricating oil base oil. The method includes: cutting the heavy feedstock to obtain a light component, a middle fraction, and a bottom wax; wherein the boiling point ranges of the light component, the middle fraction, and the bottom wax are 170-300℃, 300-500℃, and >500℃, respectively; subjecting the bottom wax to a first isomerization reaction under the catalysis of a first isomerization catalyst to obtain a first isomerization product; subjecting the first isomerization product and the middle fraction to a second isomerization reaction under the catalysis of a second isomerization catalyst to obtain a second isomerization product; subjecting the second isomerization product to hydrorefining; and then fractionating the obtained refined product to obtain the lubricating oil base oil. The lubricating oil base oil produced by this method has high yield, low pour point, low cloud point, and high viscosity index, making it a high-quality lubricating oil base oil.

The invention relates to the field of preparation of pseudo-boehmite, and discloses a method for integrally preparing pseudo-boehmite. The method comprises the following steps: in a pseudo-boehmite preparation device, carrying out carbonization reaction and crystallization on carbon dioxide in industrial flue gas and an alkaline aluminum source solution; the device comprises a closed tank body, an air inlet pipe, a liquid inlet pipe and a temperature controller, the gas inlet pipe is used for introducing industrial flue gas into the closed tank body; the liquid inlet pipe is used for introducing an alkaline aluminum source solution into the closed tank body; the closed tank body is used for carrying out carbonization reaction and crystallization on carbon dioxide and an alkaline aluminum source solution in industrial flue gas to obtain a crystallized product; and the temperature controller is used for regulating and controlling the temperature in the closed tank body. By adopting the method provided by the invention to prepare the pseudo-boehmite, integration of a carbonization reaction unit and a crystallization unit can be realized, so that the impurity crystal content of the prepared pseudo-boehmite is obviously reduced.

This invention discloses a solution-based epitaxial growth method for perovskite thin films and its preparation method, belonging to the field of perovskite optoelectronic device technology. Addressing the difficulty of achieving high-quality multilayer structures and crystal orientation control using existing solution methods, this invention first prepares a perovskite template layer with a preferred orientation on a substrate, and then uses thermal shock treatment to induce rapid crystallization of a second precursor solution under the guidance of the template layer's lattice structure. This method utilizes a solvent with inverse temperature solubility (such as 2-methoxyethanol), effectively solving the solvent orthogonality problem and achieving epitaxial growth of perovskite crystals. The resulting thin film exhibits a (001) preferred orientation throughout its thickness direction, with a Herman orientation factor as low as −0.36 and a trap state density as low as 1.62 × 10⁻⁶. 15 cm −3 The perovskite solar cells prepared using this method achieve a photoelectric conversion efficiency of 25.58% and exhibit excellent stability under high temperature and high humidity conditions. This invention features a simple and low-cost process, and is suitable for large-area fabrication and various perovskite material systems.

The utility model discloses a continuous lactose production crystallizing tank which comprises a tank body, an end cover is connected to the upper end of the tank body, a partition plate is connected to the middle in the tank body, an outer shaft is rotationally connected to the end cover, an inner shaft is rotationally connected into the outer shaft, the lower end of the outer shaft is rotationally connected with the partition plate, and the inner shaft penetrates through the partition plate and extends to the lower portion in the tank body. A driving box is mounted on the end cover; a first driving mechanism for driving the outer shaft to rotate and a second driving mechanism for driving the inner shaft to rotate are arranged in the driving box; the outer shaft is detachably connected with a plurality of turbo-type stirring paddles, and the outer wall of the lower part of the inner shaft is detachably connected with a frame-type stirring paddle; an overflow groove is formed in the partition plate, a plurality of overflow pipes communicated with the overflow groove are connected to the periphery of the bottom of the partition plate, and the inner wall of the overflow groove inclines towards the overflow pipes on the two sides. Through vertical zoning and differential stirring in the tank body, the continuous flow of crystal nucleus generation, growth and ripening is realized in the same tank body, and the crystallization time is shortened.

The invention belongs to the technical field of biological fermentation and crystallization separation, discloses a method and a system for producing isomaltulose by coupling double-bacterium synergistic fermentation with gradient temperature control crystallization, and solves the problem that glucose generates feedback inhibition on sucrose isomerase in a fermentation stage. The method comprises a fermentation stage and a crystallization stage, a double-bacterium synergistic fermentation system of recombinant bacillus subtilis engineering bacteria and recombinant pichia pastoris engineering bacteria is adopted in the fermentation stage, and the inoculation ratio of the recombinant bacillus subtilis engineering bacteria to the recombinant pichia pastoris engineering bacteria is 3: 1-5: 1; in the crystallization stage, a gradient temperature control-ultrasonic-assisted coupling crystallization process is adopted, after the fermentation liquor is subjected to concentration pretreatment, the temperature is reduced to 25-28 DEG C at the speed of 0.5-0.8 DEG C / h, and heat preservation and ultrasonic treatment are performed; and cooling to 15-18 DEG C at the speed of 0.3-0.5 DEG C / h, preserving heat and carrying out ultrasonic treatment. The method provided by the invention realizes efficient production and accurate purification of isomaltulose.

This invention relates to the field of catalysts for the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime, and discloses a method for preparing the catalyst and the method for the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime. The method includes: mixing a molecular sieve mother liquor, an organosilicate, an organic template agent, and KOH to obtain a colloidal mixture; subjecting the colloidal mixture to a crystallization reaction; separating the obtained crystallization product into a solid-liquid mixture to obtain a wet molecular sieve and a crystallization mother liquor; drying the wet molecular sieve to obtain a raw molecular sieve powder; optionally mixing the raw molecular sieve powder with a binder, and then rotating it to obtain spherical particles; calcining the spherical particles, and then contacting them with an alkaline buffer solution containing ammonium salt, ammonia, magnesium salt, and bromide salt. This catalyst, when applied in fixed-bed or moving-bed reactions, enables long-cycle, continuous production of caprolactam with a high conversion rate of cyclohexanone oxime.