13results about How to "Less by-products" patented technology

The invention discloses a catalyst and a preparation method thereof, and a system and a method for continuously preparing methylhexahydrophthalic anhydride, and belongs to the technical field of methylhexahydrophthalic anhydride preparation. The catalyst has a double-layer structure, the outer layer is a stainless steel hollow structure, and the inner layer is a Raney nickel-cobalt metal structure. The catalyst not only has high activity and high hydrogenation efficiency of a Raney nickel catalyst, but also has the advantages of high strength, long service life, strong stability and the like, and can be used for preparing methylhexahydrophthalic anhydride. Besides, according to the system for continuously preparing methylhexahydrophthalic anhydride provided by the invention, the hydrogenation process is divided into two sections, and the catalyst is used for the second-section hydrogenation process, so that higher hydrogenation efficiency, shorter hydrogenation residence time and higher production efficiency can be obtained in this way, the saturation degree of a hydrogenation product is high, and the yield of the product is increased. The method has the advantages of low iodine value, light color number, high purity, higher yield, few byproducts and the like.

The present invention provides a lithium extraction process from lithium-containing wastewater, which comprises the following steps: low-temperature concentration and impurity removal: the lithium-containing wastewater stock solution is evaporated and concentrated by an evaporation crystallization device, so that the primary mixed salt in the stock solution is continuously precipitated and discharged, and the lithium-containing wastewater mother liquor is cyclically evaporated and concentrated to form a lithium concentrated solution and a primary vapor; chemical impurity removal: the lithium concentrated solution is mixed and stirred with an alkaline solution to generate a secondary mixed salt, a lithium concentrated mother liquor after impurity removal, and a secondary vapor; lithium precipitation reaction: the lithium concentrated mother liquor is mixed and stirred with a sodium carbonate solution and heated to generate a lithium carbonate precipitate, a lithium precipitation mother liquor, and a tertiary vapor; the lithium carbonate generated in the lithium precipitation reaction step is centrifugally filtered and washed to obtain a lithium carbonate product. With such an arrangement, the process is simple, no harmful by-products are generated, and the lithium recovery rate is high.

The invention relates to the technical field of wastewater treatment, in particular to a heavy metal capturing agent and a preparation method and application thereof. The heavy metal capturing agent provided by the invention comprises a compound with a structure as shown in a formula (I) and ferrous sulfide, and in the formula (I), R1 is C1-C6 alkylene. The heavy metal capturing agent is formed by using a compound of double-active sulfur atoms and acrylamide groups with strong chelating property and ferrous sulfide, heavy metals are chelated by using the double-active sulfur atoms, and the chelated heavy metals are flocculated by using good flocculability of the acrylamide groups; meanwhile, ferrous sulfide is oxidized in water to form ferric hydroxide with a coagulation effect, heavy metal is further flocculated and settled, the settling rate and removal efficiency of the heavy metal are improved, meanwhile, hydroxyl free radicals generated by the ferrous sulfide can degrade organic complexing ligands, the complexing property of wastewater is reduced, and the heavy metal removal efficiency is improved. The complexing agent is prevented from being continuously complexed with subsequent heavy metal.

This invention relates to a method for preparing a water-soluble yellow reactive dye, comprising: adding water and ice to 2-naphthylamine-3,6,8-trisulfonic acid and slurrying, followed by a diazotization reaction to obtain a diazo material; adding water and ice to m-ureidoaniline, adding an alkali agent, and stirring to dissolve and obtain a clear m-ureidoaniline solution; adding the diazo material to the clear m-ureidoaniline solution and performing a coupling reaction at a controlled temperature to obtain a yellow base; adding water and ice to cyanuric chloride, adding dispersant CS and dispersant MF and slurrying, then adding sodium 2,4-diaminobenzenesulfonate and mixing and slurrying, with staged heating and pH adjustment to react and obtain a bicondensed material; adding the yellow base to the bicondensed material, heating and adjusting the pH, and performing a controlled reaction to obtain a dye slurry. The preparation method provided by this invention features high chroma conversion rate, short production cycle, and reasonable and efficient process, resulting in a product with excellent solubility, high fixation rate, good storage resistance, and bright color.

According to the material with the photoelectric coupling catalytic performance and the preparation method thereof, raw materials used in the process are low in price and easy to obtain, carbonized alginate aerogel is used as a material substrate, the material substrate is of a porous structure, rich functional groups exist on the surface, and adsorption and degradation of pollutants are facilitated; and the good conductivity is beneficial to transfer of photon-generated carriers and conduction of electrons in electrochemistry. Meanwhile, excessive zinc nitrate and ferric nitrate on the surface are decomposed at high temperature to generate P-type semiconductor zinc oxide and ferric oxide, P-N heterojunction is formed by the P-type semiconductor zinc oxide and ferric oxide and TiO2, and the number and oxidability of photo-generated holes on the surface of titanium dioxide are greatly improved. And secondly, due to the existence of an electric field in the reactor, anions such as Cl <-> are enriched at the anode and are oxidized into active substances such as Cl <-> by photo-generated holes on the surface of the anode, the active substances are used for oxidizing organic pollutants, and the electrochemical oxidation potential is controlled by changing the voltage, so that byproducts of salt ion free radical oxidation are reduced, and effective circulation of Cl <-> / Cl <-> is promoted.

The invention belongs to the technical field of organic pollutant degradation, and particularly relates to a CuFe2O4 modified catalytic ceramic membrane as well as a preparation method and application thereof. A preparation method of a CuFe2O4 modified catalytic ceramic membrane comprises the following steps: uniformly mixing and dissolving a copper salt, an iron salt and a gelling agent to obtain a copper ferrite sol state mixed solution; and putting the ceramic membrane into the copper ferrite sol state mixed solution, and sequentially carrying out dipping, drying and calcining treatment to obtain the CuFe2O4 modified catalytic ceramic membrane. The copper ferrite spinel material disclosed by the invention is uniformly fixed on the surface and in pore channels of the ceramic membrane through a dipping-drying-low-temperature calcining process, so that firm combination with a matrix is ensured, and the copper ferrite spinel material has the advantages of low metal dissolution, stable performance and recyclability in a reaction process; the secondary pollution risk caused by metal ion loss in traditional heterogeneous catalysis is avoided, and the application characteristics of high efficiency, low byproduct and strong stability are comprehensively embodied.

The invention provides an efficient synthesis method of ethyl 3-ethoxypropionate, and belongs to the technical field of organic synthesis. The method comprises the following steps: filling a solid bed with a catalyst, introducing a mixed material of ethyl acrylate and absolute ethyl alcohol from the bottom for reaction, enabling a material discharged from the top to enter a rectifying tower for rectification through a filter screen, obtaining ethyl 3-ethoxypropionate, enabling the obtained ethyl 3-ethoxypropionate to enter a packaging tank, and enabling excessive absolute ethyl alcohol and a small amount of ethyl acrylate and ethyl 3-ethoxypropionate to enter a batching tank for circular reaction. The preparation method of the ethyl 3-ethoxypropionate is simple, efficient and low in cost, the catalyst is easy to recycle, the catalytic activity is high, the product yield is high, few byproducts are produced, the product purity is high, and the method has wide application prospects.

The invention relates to a kind of cyperus argyi carbonyl transferase AqCGT51 The invention discloses a gene and its application in preparing bergenin, belonging to the field of biotechnology. AqCGT51 The nucleotide sequence of the gene is shown in SEQ ID NO.1, and the full length of the sequence is 1455 bp; the amino acid sequence of the encoded protein is shown in SEQ ID NO.2, and it encodes 484 amino acid residues. AqCGT51 The gene can be used as a biosynthesis regulatory gene for bergenin and can be used to prepare bergenin. It has significant application prospects and is easy to promote and apply.

The application provides a preparation method of 3-hydroxypropionitrile, and belongs to the technical field of fine chemical preparation. The preparation method comprises the following steps: 1) mixing water, an alkali catalyst and an inorganic salt to obtain a mixed solution; the salt concentration in the mixed solution reaches a saturated or supersaturated state; 2) under stirring, adding acrylonitrile into the mixed solution to perform a hydration reaction; during the reaction, the generated 3-hydroxypropionitrile continuously precipitates from the aqueous phase under the action of salting-out effect, and an independent oil phase is formed; and 3) after the reaction is completed, the oil phase is separated to obtain 3-hydroxypropionitrile. The method provided by the application does not use an organic solvent, the process is simple, the product has high yield and good purity.

The invention discloses a diacerein impurity preparation method, which comprises: S1, mixing rhein, a catalyst, acetic anhydride and a solvent, stirring to dissolve, carrying out a stirring reaction at a room temperature, adding dichloromethane and an ammonium chloride saturated solution after the reaction is completed, carrying out liquid separation, and carrying out rotary evaporation on the organic phase to obtain an intermediate; and S2, uniformly mixing the intermediate obtained in the step S1 and tetrahydrofuran, stirring in an ice-water bath for 0.5-1 hour, then dropwise adding a borane tetrahydrofuran complex under the protection of nitrogen, reacting in the ice-water bath after dropwise adding is completed, transferring to room temperature after the reaction is completed, continuously carrying out constant-temperature reaction, adding dichloromethane and purified water after the reaction is completed, carrying out liquid separation, and drying an organic phase, so as to obtain the borane tetrahydrofuran catalyst. And carrying out silica gel column chromatography and recrystallization to obtain the diacerein impurity. The diacerein impurity is creatively synthesized for the first time, and the diacerein impurity prepared by the method has the advantages of few byproducts, high product purity and the like.

The application belongs to the technical field of polyether preparation, and discloses a solid superbase catalyst and a method for preparing isomeric alcohol polyether by using the same. The solid superbase catalyst comprises a catalyst carrier and a strong base loaded on the catalyst carrier; the strong base is at least one selected from CH3OK, CH3ONa, KOH and NaOH; and the catalyst carrier comprises one of MgO, ZrO2 and Al2O3. The solid superbase catalyst provided by the application is composed of a catalyst carrier and a strong base loaded on the catalyst carrier, and has high catalytic activity and high reaction efficiency. When the solid superbase catalyst is used as a catalyst, isomeric alcohol polyether with low odor, narrow molecular weight distribution and few by-products can be prepared.

L-aspartic acid N,N-diacetic acid tetrasodium salt and a preparation method therefor. The preparation method comprises: hydrolyzing at least one of maleic anhydride, maleic acid and fumaric acid to obtain a hydrolyzed salt solution; and subjecting the hydrolyzed salt solution and glycine to a Michael addition reaction, and then carrying out a catalytic reaction with chloroacetic acid. The preparation method for L-aspartic acid N,N-diacetic acid tetrasodium salt has a low cost, a high yield and few by-products.

The present invention relates to a kind of glycosyltransferase ApCGT67 The invention discloses a gene and its application in preparing bergenin, belonging to the field of biotechnology. ApCGT67 The gene nucleotide sequence is shown in SEQ ID NO.1, and the full length of the sequence is 1356 bp; the amino acid sequence of the encoded protein is shown in SEQ ID NO.2, and it encodes 451 amino acid residues. ApCGT67 The gene can be used as a biosynthesis regulatory gene for bergenin and can be used to prepare bergenin. It has significant application prospects and is easy to promote and apply.