30results about How to "Overcome the disadvantage of low yield" patented technology

The invention discloses a nitrogen-doped activated carbon supported noble metal catalyst and an application thereof. The catalyst is composed of a carrier and an active component; the carrier is nitrogen-doped activated carbon; the active component is one of palladium, platinum, rhodium, ruthenium and iridium; and the load of the active component is not higher than 15wt% based on the mass of the carrier. The invention provides the application of the nitrogen-doped activated carbon supported noble metal catalyst to reaction for preparing an alkyl-containing halogenated aromatic aminocompound shown as a formula (II) by carrying out catalytic hydrogenation reduction on an alkyl-containing halogenated aromatic nitrocompound shown as a formula (I) to show that the nitrogen-doped activated carbon supported noble metal catalyst has the characteristics of high hydrogenation reaction rate, high catalytic activity, high selectivity and high stability.

The invention provides a grinding sheet for a disc grinder and a manufacturing method thereof. The grinding sheet comprises grinding teeth and grinding sheet base body which are respectively processed twice for forming, wherein the grinding teeth which are arranged into a plurality of concentric circles are uniformly distributed on the grinding sheet base body around a center shaft of the grinding sheet base body, pulp baffle plates are arranged among the grinding teeth, and the pulp baffle plates positioned on a same circle form spiral pulp baffling lines on the surface of the grinding sheetbase body. The manufacturing method of the grinding sheet comprises the following steps: firstly, manufacturing the grinding teeth needed by the grinding sheet, and carrying out the surface processing of the grinding teeth; then processing a mould according to the designed form of the grinding sheet, installing the grinding teeth and the pulp baffle plates on the mould, and then casting or vulcanizing the mould provided with the grinding teeth; forming the grinding sheet base body, and simultaneously fixing the grinding teeth on the grinding sheet base body; and finally cooling a taper to finish the manufacturing process. The grinding sheet has good pulp grinding effect and long service life; in addition, the grinding sheet adopts a post forming method, thereby greatly reducing the material cost of the grinding sheet and the waste of materials.

The invention relates to an extraction and preparation process of citrus pectin. The extraction and preparation process of citrus pectin includes additionally pretreating dried citrus peel, and extracting pectin from the citrus peel by multiple microwave-heating. By the extraction and preparation process of citrus pectin, extraction time is shortened, and the defect of low pectin yield due to the fact that pectin degrades under long-term heating in strong acid extraction is overcome. By the extraction and preparation process of citrus pectin, the yield is higher with less extraction time and simple extraction steps, the pectin has better gloss, energy consumption is lowered, and production cost is reduced.

The invention relates to a method for preparing a metal organic framework material UiO-66 (Zr) in an ethanol phase. The method comprises the following steps: (1) uniformly mixing a zirconium source and an organic ligand, and pretreating for 1-3 hours so as to obtain an intermediate; (2) adding the intermediate into ethanol, stirring under a normal temperature condition, and centrifuging so as to obtain a crude product; and (3) washing the crude product for multiple times with ethanol, and drying, thereby obtaining the metal organic framework material UiO-66 (Zr). Compared with the prior art, the method is not involved with toxic organic solvents such as N,N-dimethyl formamide used in a conventional solvent thermal method, after the raw materials are pretreated, the UiO-66 (Zr) can be synthesized by using the ethanol as a solvent under the room temperature condition, the condition is gentle, the yield is relatively high, and large-scale synthesis of metal organic framework materials is possible.

The invention discloses a method for preparing ethanol from a cellulose-containing raw material, which comprises the following steps: in the presence of water, mixing a cellulose-containing raw material with enzyme, carrying out enzymolysis on the cellulose-containing raw material to obtain an enzymolysis product, and fermenting the enzymolysis product. The enzymolysis comprises a main enzymolysis stage and an intermitted enzymolysis stage after the main enzymolysis stage which are continuously performed, wherein in the main enzymolysis stage, proper amounts of the cellulose-containing raw material and enzyme are continuously added into an enzymolysis tank so that the monosaccharide content in the enzymolysis product in the main enzymolysis stage is 50-100 g/L, and the enzymolysis products of the main enzymolysis stage respectively and continuously flow into enzymolysis tanks of the subsequent stage to perform intermitted enzymolysis until the monosaccharide content in the enzymolysis products in the enzymolysis tanks in the subsequent stage at the enzymolysis end point is greater than or equal to 105 g/L. The method can effectively enhance the saccharide conversion rate of the raw material, and therefore, greatly enhances the yield of ethanol.

The invention discloses a preparation method of pyrophosphate piperazine. The preparation method comprises the following steps: mixing ammonium dihydrogen phosphate and piperazine in an aqueous solution according to a mole ratio of 2:1, heating to remove ammonia, and dewatering for condensation to obtain the pyrophosphate piperazine. According to the preparation method, the shortcomings that conventional liquid phosphoric acid serving as a phosphorous source is difficult to transport and store are overcome; a reaction system is a weak-alkaline environment, so that erosion of the phosphoric acid serving as the phosphorous source to equipment is avoided; ammonia released during reaction can be used as protection atmosphere of the reaction system, and the whiteness value of a product meets the market requirement. Compared with a phosphoric acid-piperazine method, the preparation method has the advantage of saving the raw material cost by 10 to 15 percent.

The invention relates to a zirconium-based metal organic framework material UiO-66 (Zr) as well as a room-temperature rapid preparation method and application thereof. The preparation method comprises the following steps of: (1) uniformly mixing a zirconium source and an organic ligand, placing the mixture in methanol, stirring the mixtureat room temperature, performing centrifuging, and discarding clear liquid to obtain a transparent gel-state intermediate product; and (2) heating and drying the intermediate product to obtain the UiO-66 (Zr). Compared with the prior art, the UiO-66 (Zr) can be synthesized only by performing stirring in methanol at room temperature and performing drying without using toxic organic solvents such as N, N-dimethylformamide and the like in a traditional solvothermal method, the conditions are mild, the yield is higher, the synthesis time is greatly shortened, the product purity is extremely high, the step of activating the product can be omitted, the large-scale synthesis of the metal organic framework material is highly possible; and the material has good adsorption performance on fluorine ions in water, and can be applied to adsorption treatment of fluorine-containing wastewater.

The invention belongs to the field of natural organic chemistry and relates to a method for extracting and purifying total alkaloids from wild thermopsis lanceolata in Greater Khingan Mountains and particularly relates to a method for finally obtaining high-purity total alkaloids by using a biological enzymolysis technology and through ultrahigh pressure coupled subcritical water extraction, separation and refining by using an enzymatic method as well as separation and purification by using a high-speed counter-current chromatography. The method has the advantages that 1, the effective components of the alkaloids are rapidly dissolved out and the high activity is kept by using a biological exine detaching technology, and the method is carried out at normal temperature and is low in energy consumption and capable of realizing industrial production; 2, the subcritical water is nontoxic and pollution-free, so that the activity of an extract is not damaged; the operation cost is low, the extract is easy to be separated from a product, and large-scale industrial production can be realized; 3, the high-speed counter-current chromatography has the advantages of flexibility in operation, high efficiency, high separation speed, large preparation amount, low expense and the like, and can be used for industrial application. By using the method, the obtained total alkaloids are high in content and high in purity up to 95.8%.

The invention relates to a method for simultaneously preparing cellulose nanocrystals and cellulose nanofibers from oil-tea camellia husk, which comprises the following steps: by taking the oil-tea camellia husk as an initial raw material, firstly carrying out alkali washing and bleaching to obtain crude fibers, carrying out preliminary hydrolysis on the crude fibers by using diluted hydrochloric acid to obtain microcrystalline cellulose, and then carrying out acidolysis on the microcrystalline cellulose by using a sulfuric acid hydrolysis method; washing and centrifuging at a high speed to obtain a cellulose nanocrystal suspension on the upper layer, and further performing high-pressure homogenization on the lower layer to obtain a cellulose nanofiber suspension. According to the method, CNC and CNF are prepared at the same time according to the difference of the crosslinking degree of cellulose, a sparse structure in a cellulose crystalline region is broken into CNC under the action of sulfuric acid, the tightly-combined part in the crystalline region swells through acidolysis, and CNF can be obtained through homogenization under low pressure. The method is beneficial to improving the yield of the oil-tea camellia husk nano cellulose and reducing the production cost of the process.

The invention discloses an extracting process of lavender essential oil and belongs to the technical field of essential oil extraction. The extracting process comprises the following steps that newly-picked lavenders are dried and crushed, the crushed lavenders are divided into three parts, distilled water is added, and the liquid-solid ratios of three parts of liquid-solid mixtures are (10 to 22):1 and are increased sequentially; and then the three parts of liquid-solid mixtures are sequentially subjected to ultrasonic enhancement treatment, and then then steam distillation is conducted. According to the extracting process of the lavender essential oil, the mixtures, with the different liquid-solid ratios, of the distilled water and the lavenders are subjected to ultrasonic enhancement step by step, steam distillation is conducted finally, thus the defect of low yield of a traditional steam distillation method is overcome, and effective components in the lavender essential oil are notdamaged; and the extracting process is easy to operate and low in production cost, no organic solvent is adopted, thus medicine residue is avoided, the equipment requirement is low, and the extracting process is completely suitable for industrial production.

The invention relates to an efficient and fast method for extracting shrimp head inclusions, comprising the following steps: a shrimp head of a plurality of shrimps such as fresh Litopenaeus vannamei, penaeuschinensis, metapenaeusensis and penaeusjaponicus serves as the raw material; adding a small amount of exogenous enzyme; fully activating activity of endogenous enzyme by adjusting pH value and temperature; employing coordinate hydrolytic action of the exogenous enzyme and the endogenous enzyme for efficiently extracting inclusions in the shrimp head; competing extracting inclusions in the shrimp head in 3h; in the invention, proteolysis degree of the shrimp head is more than 48%, protein recovery rate is more than 87%, the extractive is free from bitter taste, content of flavor-presenting amino acids is high, amino acid composition is balanced and nutrition is comprehensive; therefore the shrimp head inclusions are a good material for preparing seasoner and nutritional food.

The invention discloses a method for preparing (phthimide-N-oxyl) derivatives by direct coupling of NHPI (N-hydroxyphthalimide) and ketone compounds. The method includes that, under the protection of nitrogen, the ketone compounds react with N- hydroxyphthalimide and K2S2O8 under catalyzing of tetraalkyl ammonium salt to generate the PINO derivatives. With the method, the PINO derivatives are synthesized with high yield by one-step reaction under the moderate condition, low cost is achieved, simpleness in operation is realized, and industrial production requirements are met.

The invention provides a method for preparing high-whiteness short-column submicron-scale alpha-hemihydrate gypsum by using desulfurized gypsum. The method comprises the following steps: adding N,N'-methylene bisacrylamide, water and desulfurized gypsum into a reaction container, carrying out mixing to prepare reaction slurry, and heating the slurry to 120-125 DEG C for a reaction for 2-5 hours; carrying out filtering, carrying out washing to neutrality, and carrying out drying to obtain an intermediate product; mixing the water, the intermediate product, NaCl, succinic acid and ethylene glycol to prepare reaction slurry; then carrying out a reaction on the reaction slurry in a stirring homogeneous reactor at a temperature of 120-125 DEG C for 3-4 hours; and carrying out filtering and drying to obtain the high-whiteness short-column submicron-scale alpha-hemihydrate gypsum. According to the invention, a problem of accumulation and secondary pollution of waste resource desulfurized gypsum is solved, and a novel method is also provided for producing small-particle gypsum with high whiteness and certain strength.