8 results about "Diketene" patented technology

The application discloses a preparation and by-product recycling process of acesulfame potassium, and belongs to the technical field of food additive production and processing. Amino sulfonic acid is added into N-butyl pyridine hydrogen sulfate ionic liquid and triethylamine in batches to obtain a homogeneous mixed solution; secondly, the mixed solution and diketene are introduced into a micro-channel reactor to perform a condensation reaction; and the discharge liquid is introduced into a polystyrene sulfonic acid resin loaded SO3 fixed bed reactor to perform a cyclization reaction; subsequently, the cyclization product is subjected to hydrolysis, decolorization, potassium salt crystallization and drying to obtain the acesulfame potassium product; and the crystallization mother liquor is separated through a nanofiltration membrane, and the intercepted liquid is an ionic liquid and triethylamine mixture, which is directly reused. The application inhibits the self-polymerization of diketene through the micro-channel reactor, replaces concentrated sulfuric acid with solid acid to avoid waste acid pollution, and realizes efficient recycling of by-products by combining nanofiltration membrane separation and catalytic depolymerization technology, and has the characteristics of green environmental protection and economic efficiency.

The application discloses a method for synthesizing (R)-( - )-1,3-butanediol by a one-step method of diketene, which uses a chiral ruthenium complex as a catalyst and a Bronsted acid as an assistant to make the diketene react by a one-step method under certain temperature and hydrogen pressure conditions to obtain (R)-( - )-1,3-butanediol. The method solves the problems of high cost, large catalyst consumption and difficult product separation in the prior art for preparing (R)-( - )-1,3-butanediol, and can asymmetrically hydrogenate the carbonyl group of the substrate diketene at low cost and with a small amount of catalyst, simultaneously reduces the ester group and opens the ring to obtain (R)-( - )-1,3-butanediol. The method has simple reaction operation and simple catalyst preparation, the yield of the target product and ee value are both above 98%, meanwhile, the catalyst can be repeatedly used, the cost is greatly reduced, and the method has the potential for industrial application.

The invention discloses an energy-saving diketene quench cooler, which belongs to the technical field of quench coolers, and comprises a shell, the top and the bottom of the shell are respectively provided with a cooling liquid inlet and a cooling liquid outlet, and the left side and the right side of the shell are respectively provided with a material inlet and a material outlet; the fixing plates are fixed to the top and the bottom of the interior of the shell, heat exchange pipes penetrate through the interiors of the fixing plates at equal angles, a draught fan is installed on the outer wall of the shell, and the draught fan is connected with a cooling mechanism through the fixing pipes; and the adjusting mechanism is arranged in the heat exchange pipe, and the adjusting mechanism is used for adjusting the flow speed of the cooling liquid in the heat exchange pipe. According to the energy-saving diketene quench cooler, materials are cooled in the mode that cooling liquid and blowing are combined, the cooling efficiency can be improved, the cooling time can be shortened, and when the amount of the cooling liquid in the heat exchange pipes is the same, the flow speed of the cooling liquid can be adjusted according to the cooling requirement.

The application provides a method for preparing beta-butyrolactone through asymmetric hydrogenation of diacetylene ketone, which is prepared through catalyzing asymmetric hydrogenation of diacetylene ketone under a hydrogen atmosphere by using a metal active component and a pyridine ring phosphine ligand as a catalyst. The method uses a hydroxyl-containing nitrogen heterocyclic phosphine ligand as a ligand, and a metal such as palladium, rhodium or ruthenium as an active metal, so that the conversion rate and selectivity of the reaction are improved, the stability of the catalyst is good, and the catalyst can be used multiple times. The synthesis route of the catalyst used in the method is short, the yield is high, the number of times of reusing is large, and the method has a good cost advantage.

The invention discloses a method for directly preparing aromatic hydrocarbon from diketene, belongs to the technical field of preparation of aromatic hydrocarbon in coal chemical industry, and can solve the problems of harsh reaction conditions, low selectivity of aromatic hydrocarbon, low selectivity of benzene, toluene and xylene (BTX) and the like in the existing process of preparing aromatic hydrocarbon from methanol and preparing aromatic hydrocarbon from synthesis gas. The reaction raw material adopts diketene, and aromatic hydrocarbon is generated under the catalytic action of the molecular sieve catalyst. The selectivity of aromatic hydrocarbon can reach 78.2%, the selectivity of BTX is 77.6%, and the selectivity of BTX in aromatic hydrocarbon can reach 99.2%. Although the currently reported selectivity of preparing aromatic hydrocarbon from synthesis gas can reach 70.0%, the BTX selectivity is not high and is only 45.0%; in the process of preparing the aromatic hydrocarbon from the methanol, the BTX can only reach 30.0%-45.0%.

The invention discloses a catalyst for preparing ketene through selective hydrogenation of diketene as well as a preparation method and application of the catalyst. The catalyst comprises an active component, a carrier and a modification aid, the active components are primary metal ruthenium and secondary metal palladium; the carrier is one of erbium oxide and samarium oxide; the modification auxiliary agent is one of mercaptoamines. When the catalyst is applied to preparation of ketene through selective hydrogenation of diketene, the conversion rate and selectivity are high, the reaction conditions are mild, the hydrogen pressure is lower, and the catalyst is suitable for industrial production.

The invention discloses a preparation method of a beta-diketone functionalized vegetable fat extraction agent and application of the beta-diketone functionalized vegetable fat extraction agent in lithium extraction. The method comprises the following steps: hydrolyzing vegetable fat (such as sunflower seed oil, rapeseed oil and the like) to obtain unsaturated fatty acid, esterifying with ethylene glycol to generate fatty acid with hydroxyl, and finally modifying with diketene to obtain the beta-diketone functionalized extracting agent. The extraction agent solves the problems that a traditional beta-diketone extraction agent is serious in emulsification and long in phase separation time and has excellent lithium extraction performance, the extraction capacity reaches 1.44 g / L, and the lithium / sodium separation factor can reach 286.5. In addition, the extraction agent is low in solution loss, the efficiency is still kept above 80% after the extraction agent is recycled for 10 times, and the extraction agent is suitable for efficiently recovering lithium ions from lithium-containing wastewater. The method is simple in process and low in cost, and has large-scale application potential.

The application discloses a full synthesis method of cephinold H and fortalpinoid C, comprising the following steps: taking natural product cephanolide B as a raw material, carrying out oxidative de-arrangement and acetylation to obtain a dienone compound, then carrying out ring expansion rearrangement to obtain natural product cephinold H as a secondary product, then introducing an occupying group (Br or Cl atom) to improve the regioselectivity of the ring expansion rearrangement, so that a ring expansion product substituted with a halogen atom (Br or Cl atom) is obtained in a high proportion, then removing the halogen atom (Br or Cl atom) under a palladium catalytic reduction condition to obtain natural product cephinold H, then oxidizing cephinold H by selenium dioxide and reducing by sodium borohydride to obtain natural product fortalpinoid C with opposite configuration, and finally inverting the configuration of the hydroxyl group through a Mitsunobu reaction, so that the chemical synthesis of fortalpinoid C is realized, and the synthesis route has the advantages of simplicity, high efficiency, simple operation, low cost and the like, and is suitable for the mass synthesis of cephinold H and fortalpinoid C, and provides an important material basis for the bioactivity evaluation of the two products.