534results about "Urea derivatives preparation" patented technology

The invention discloses an efficient anti-crystallization urea solution for vehicles and a preparation method thereof, and belongs to the technical field of preparation of urea solutions for vehicles, the preparation method comprises the following steps: preparing an inclusion compound, hydrolyzing and crystallizing, dissolving, filtering, finely filtering and ultra-filtering; the hydrolytic crystallization method comprises the following steps: mixing industrial urea and three-stage water, stirring at 70-75 DEG C for 30-40 minutes, carrying out first gradient cooling and second gradient cooling, adding an inclusion compound, carrying out third gradient cooling and fourth gradient cooling, preserving heat, centrifuging, and taking a precipitate. During preparation, the industrial urea is used as a raw material, the prepared efficient anti-crystallization urea solution for the vehicle is low in impurity content, free of precipitates and high in urea yield, the urea yield is slightly influenced by the impurity content in the industrial urea, and when precipitates in the urea solution are removed through an ultrafiltration method, the membrane flux is slightly influenced by the precipitate content in the urea solution; the problem of membrane pollution can also be avoided.

The invention belongs to the technical field of drug synthesis, and particularly relates to an adamantane derivative as well as a synthesis method and application thereof. The adamantane derivative comprises an intermediate structural formula I, an intermediate structural formula II and an intermediate structural formula III, and the structural general formula is as follows: Linker is substituted or unsubstituted C6-C10 aroyl, R1 is hydrogen or C1-C6 alkyl, R2 is hydrogen, C1-C6 alkyl or a nitrogen-containing or nitrogen-free structural fragment, or the integral structure of R1R2 is N-substituted heterocyclic pentyl or heterocyclic cyclohexyl. According to the adamantane derivative provided by the invention, an adamantane structure is combined with part of groups of OAB-14, and a parent nucleus structure is changed, so that the drug activity is improved. The invention also provides a synthesis method of the compound, the obtained compound is screened through cell viability research, and the compound has a potential synergistic effect in the aspects of preventing influenza and treating Alzheimer's disease.

A hydrogen production system for producing a hydrogen gas product includes a geologic hydrogen source configured to provide a feedstock comprising hydrogen, nitrogen, and helium and purification equipment comprising two or more of: a pressure swing adsorption (PSA) device; a guard bed; a separation membrane; a reactive membrane; or a cryogenic separation device. The purification equipment is configured to receive the feedstock from the geologic hydrogen source and produce a hydrogen gas product, and production of the hydrogen gas product exhibits a carbon intensity score less than 3.0 kg CO2 eq / kg H2.

This invention discloses a method for improving the yield of urea phosphate in the preparation of wet-process phosphoric acid. The method involves mixing a crystallizer with wet-process phosphoric acid and urea, reacting the mixture, and then cooling, crystallizing, filtering, and drying to obtain urea phosphate. Alternatively, wet-process phosphoric acid is mixed with urea and reacted. After the reaction, a crystallizer or a urea phosphate mother liquor containing the crystallizer is added, followed by cooling, crystallizing, filtering, and drying to obtain urea phosphate. The crystallizer is one or a mixture of two or more of ethylene glycol methyl ether, ethylenediaminetetraacetic acid, and citric acid in any proportion. The urea phosphate produced by this method is in crystalline form, meeting the industrial urea phosphate standard (GB / T27805-2011), satisfying market demand, and featuring a low-cost crystallizer with flexible addition methods, making it very convenient for practical production.

The invention belongs to the technical field of synthesis, and particularly relates to a synthesis method of urea [14C]. The synthesis method of the urea [14C] comprises the following steps: (1) reacting carbonate [14C] with ammonia gas to obtain cyanamide salt [14C]; (2) hydrolyzing the cyanamide salt [14C] obtained in the step (1) with concentrated sulfuric acid at the hydrolysis temperature of 35-45 DEG C; and (3) adjusting the pH value of the hydrolysate obtained in the step (2) with ammonia water, concentrating and purifying to obtain urea [14C]. The synthesis method provided by the invention has the advantages of mild conditions, efficient reaction, high product yield (up to 95% or above), high purity (the chemical purity is greater than or equal to 99%) and the like, and is suitable for large-scale preparation of key raw materials of helicobacter pylori diagnostic reagents.

The objective of the present invention is to provide a method for producing a halogenated carbonyl safely and efficiently. The method for producing a halogenated carbonyl according to the present invention is characterized in comprising the step of applying ultrasound to a composition containing a C1-4 halogenated hydrocarbon having one or more halogeno groups selected from the group consisting of chloro, bromo and iodo in the presence of oxygen to decompose the C1-4 halogenated hydrocarbon.

The invention belongs to a urea synthesis system using liquid carbon dioxide and a urea synthesis method. Comprising a urea synthesis tower, the urea synthesis tower is respectively connected with a liquid ammonia pipeline and a carbon dioxide gas pipeline, the carbon dioxide gas pipeline is connected with an outlet of a liquid-phase carbon dioxide delivery pump through a liquid-phase carbon dioxide vaporization unit, and an inlet of the liquid-phase carbon dioxide delivery pump is connected with a liquid-phase carbon dioxide delivery pipeline; liquid carbon dioxide is directly used as a raw material, a liquid-phase carbon dioxide delivery pump is used for pressurization, and gasification is carried out after pressurization, so that the liquid carbon dioxide meets the requirements of a urea synthesis tower, and the characteristics of saving urea synthesis energy consumption, reducing the use amount of circulating water and reducing the occupied area of equipment are achieved.

A process includes feeding atmospheric air to an air separation unit to produce a flow of nitrogen and a flow of oxygen; combining the oxygen with a hydrocarbon flow and water in an auto-thermal reformer to produce a retentate stream to a membrane water gas shift reactor (M-WGSR); generating, from the retentate stream to the M-WGSR, a permeate stream from the M-WGSR that includes a first flow of carbon dioxide and a first combined flow of hydrogen and nitrogen; feeding a retentate stream to a membrane steam methane reformer (M-SMR) to produce a permeate stream from the M-SMR that includes a second flow of carbon dioxide and a second combined flow of hydrogen and nitrogen; feeding the first and second combined flows to an ammonia synthesis unit to produce ammonia; and feeding the first and second flows of carbon dioxide and the ammonia to a urea synthesis unit to produce a flow of urea by fully utilizing the carbon dioxide.

The present invention relates to a compound represented by formula (I) or a stereoisomer, tautomer, solvate or pharmaceutically acceptable salt of a compound represented by formula (I), TIFF2026503201000033.tif3981X1, X2 and X3 are each independently an optionally substituted C1-C 15 alkylene, and R and R are each independently an optionally substituted C-C 40 Alkyl, optionally substituted C-C 40 Heteroalkyl, optionally substituted C-C 40 Alkenyl, optionally substituted C-C 40 Heteroalkenyl, optionally substituted C-C 40 Alkynyl or optionally substituted C-C 40 The present invention provides a compound comprising heteroalkynyl, wherein R3, R4, R5, and R6 are each independently H, halogen, or optionally substituted C1-C3 alkyl, and the substituents are independently selected from halogen, -OH, -SH, -NH2, -NO2, cyano, and C1-C3 alkyl, which has the advantages of low cytotoxicity, strong delivery ability, and strong immunostimulatory effect.

The invention belongs to the technical field of medicine synthesis, and particularly relates to a memantine derivative and a synthesis method and application thereof. The memantine derivative comprises an intermediate structural formula I, an intermediate structural formula II, an intermediate structural formula III and a structural general formula, Linker is substituted or unsubstituted C6-C10 aroyl, R1 is hydrogen or C1-C6 alkyl, R2 is hydrogen, C1-C6 alkyl or a nitrogen-containing or nitrogen-free structural fragment, or the integral structure of R1 and R2 is N-substituted heterocyclic pentyl or heterocyclic cyclohexyl. According to the memantine derivative provided by the invention, a memantine group is combined with an OAB-14 partial structure to change a parent nucleus structure, so that the drug activity is improved. The invention also provides a synthesis method of the compound, and the obtained compound is used for treating Alzheimer's disease and Parkinson's disease.

The present disclosure relates to a high pressure carbamate condensing device for a urea plant, a urea plant and a urea production method. The device comprises a first U-shaped tube bundle arranged around a second U-shaped tube bundle.

The present application relates to the technical field of urea preparation, and discloses an energy-saving urea production system, a carbon dioxide stripping tower and a high-pressure ammonia ejector are connected with a first high-pressure methylamine condenser, a second high-pressure methylamine condenser is connected between the first high-pressure methylamine condenser and a urea synthesis tower, the second high-pressure methylamine condenser can be connected with a carbon dioxide compressor, and the urea synthesis tower is connected with the upper portion of the carbon dioxide stripping tower to input urea mixture into the carbon dioxide stripping tower. The energy-saving urea production system improves the recovery rate and utilization rate of the synthesis reaction heat through the addition of the second high-pressure methylamine condenser.

The invention provides a diurea diol chain extender, light-cured polyurethane-urea acrylate as well as a preparation method and application of the light-cured polyurethane-urea acrylate. The preparation method comprises the following steps: reacting a diisocyanate compound with an alcohol amine compound, which have different structures, to generate a diurea diol chain extender containing two ureido groups; high-performance light-cured resin, namely light-cured polyurethane-urea acrylate, with a main chain containing ureido is prepared from the diurea diol chain extender, a diisocyanate compound, polyhydric alcohol and a photosensitive end-capping reagent in the presence of a catalyst, an organic solvent and a polymerization inhibitor. According to the preparation method disclosed by the invention, ureido is controllably introduced into a main chain of the light-cured resin under a mild condition; the prepared polyurethane-urea acrylate shows higher tensile strength and modulus under the double hydrogen-bond interaction of carbamido, the hardness of a coating is remarkably improved, and the polyurethane-urea acrylate is suitable for a light-cured coating material or a blocky material.

Disclosed is a process for the production of an aqueous urea solution suitable for use as a Diesel Exhaust Fluid (DEF), wherein a condensate of off-gas obtained from further purifying an aqueous urea stream in a treatment section adapted to produce DEF, is sent to an LP dissociation section, thereby the removal of ammonia therefrom. This enables water obtained from such condensate to be recirculated to the DEF purification section, and prevents an unwanted build-up of water in recirculation to urea synthesis.

Method for producing solid urea by granulation, wherein the granulation is fed with liquid urea having a purity greater than 98% by weight and not containing formaldehyde.

The present disclosure provides system and method for synthesis of green ammonia and other nitrogenous fertilizers derived from it including urea and nitric acid (as well as others that may be produced by any combination / reaction of these) by coupling renewable energy and Carnot battery with Solid-Oxide Electrolyser Cell (SOEC) and Direct Air Capture (DAC). 5 The system provides a solution for round-the-clock renewable energy using Carnot battery that provides both heat and power to run SOEC. The heat from Carnot battery is used by DAC to capture carbon dioxide from air. A nitrogen-oxygen generator may produce nitrogen using continuous power from Carnot battery. Ammonia may be produced by using hydrogen from SOEC, and nitrogen from the nitrogen-oxygen generator. Urea may be produced using 0 carbon dioxide from DAC and ammonia. Ammonia and oxygen from SOECs and nitrogen- oxygen generator may be used for synthesis of nitric acid, and other nitrogenous fertilizers. The process heat from ammonia and nitric acid synthesis is recycled back to the Carnot battery.

The present application belongs to the technical field of condensate, and particularly relates to a non-peptide small molecule condensate and preparation and application thereof. The present application provides a non-peptide small molecule condensate which is prepared by taking a small molecule shown in formula I as a precursor, wherein Y and Z are each independently NH, O or S, R = or X = O or S; R1 and R2 are each independently selected from H, C 3‑20 alkyl, -C 1‑8 alkylene-phenyl, -C 1‑8 alkylene-5-10-membered heteroaryl, -C 1‑8 alkylene-S-C 1‑8 alkyl, -C 1‑8 alkylene-SH, -C 1‑8 alkylene-O-C 1‑8 alkyl or -C 1‑8 alkylene-NH-C 1‑8 alkyl; and R1 and R2 are not H at the same time. The obtained condensate not only has good spontaneous non-classical fluorescence characteristics, but also has the abilities of drug loading and controllable release, and shows excellent resistance to enzymatic hydrolysis and good biocompatibility. Formula I

The application provides a low-temperature methanol washing and urea generation combined energy-saving system and method, comprising a feed heat exchanger, a cooling separation unit, an absorption tower, a liquid phase treatment unit and a urea synthesis unit, each unit cooperatively realizing process deep integration and energy coupling; the application takes the purified reflux liquid phase CO2 as the cooling source of the cooling separation unit, without external refrigeration, reducing low-temperature methanol washing cooling source consumption, also reducing the absorption tower treatment load, reducing its energy consumption, equipment investment and CO2 emission; the product liquid phase CO2 is directly supplied to the urea synthesis after cold energy recovery through the heat exchanger, replacing the traditional CO2 gas pressurization process, eliminating the secondary energy consumption of transportation. The multi-channel heat exchanger realizes cold energy step-by-step utilization, improving the overall energy efficiency. The application realizes self-provided cold energy and efficient energy recovery, achieves CO2 resource utilization, simplifies the process and reduces the maintenance cost, and the system is economic and environmentally friendly, and is suitable for industrial application of coal chemical industry and chemical fertilizer production.

A process and apparatus for CO2 stripping of urea, wherein urea is formed by reaction of ammonia with carbon dioxide in a vertical reactor (1); a first urea-containing stream (12) is withdrawn from an intermediate height of the reactor by means of a first downcomer (103) and is fed to a high-pressure stripping column (2); a second urea-containing stream (15) is withdrawn from an upper height of the reactor by means of a second downcomer (104) and is fed to an eductor (4) for reintroduction into the reactor together with fresh ammonia.

The present invention discloses a method for synthesizing urea using dry ice. A self-made atmospheric pressure corona discharge ionization device is used to efficiently ionize water molecules in the air to form water radical cation dimers. The resulting dimers first react with nitrogen in the air to produce hydroxylamine radical cations, which then react with carbon dioxide formed by sublimation of dry ice to further produce urea radical cations. The urea radical cations are then captured using mass spectrometry to produce urea. This method solves the problem of harsh reaction conditions and the need for high temperature and high pressure in the prior art of preparing urea using carbon dioxide. Furthermore, the method is green, mild, and catalyst-free, meeting carbon reduction requirements.

A continuous-flow synthesis method of 13C-urea, including: (S1) mixing sulphur and a methanol solution containing NH3 in a feed kettle to obtain a slurry; or mixing ammonia gas, sulphur and methanol in a feed kettle to obtain a slurry; (S2) feeding the slurry into a mixing unit; and feeding 13CO into the mixing unit to obtain a three-phase mixture; (S3) mixing the three-phase mixture in the mixing unit evenly; feeding the three-phase mixture into a continuous-flow reactor for reaction to obtain a reaction product; and (S4) feeding the reaction product into a gas-liquid separator for gas-liquid separation, and collecting a liquid phase as a crude product solution; and subjecting the liquid phase to purification to obtain the 13C-urea.

The disclosure pertains to a urea production process wherein vapor from an evaporation unit for concentrating urea solution is condensed and the resulting process condensate, which contains urea originating from urea entrained in the vapor, is combined with a second urea solution to obtain a dilute urea solution that is suitable e.g. for DEF.

A system for photocatalytic synthesis of urea includes an aqueous solution and a photocatalytic device immersed in the aqueous solution. The photocatalytic device includes a substrate having a surface, and a conductive structure supported by the substrate at the surface, the conductive structure including a nitride interface in contact with the aqueous solution. The aqueous solution includes nitrate ions and dissolved carbon dioxide for synthesis of urea at the nitride interface of the conductive structure.

The present invention discloses a photo-generated chiral radical molecule based on a triarylamine derivative with circularly polarized luminescence properties, and its preparation and application. It is prepared by subjecting tris(4-aminophenyl)amine to an amide condensation reaction with an aryl-containing chiral isocyanate or an aryl-containing chiral carboxylic acid. The triarylamine derivative molecule of the present invention has the characteristics of being easy to generate and detect chiral radicals. In addition to being detected by ultraviolet-visible absorption spectroscopy and CD spectroscopy, the generation of radicals can also be judged by color change. The planarization of the conformation of the triarylamine molecule itself after the generation of radicals makes it easy to undergo self-aggregation, thereby amplifying the chiral signal. The positive charge carried can also interact with other negatively charged molecules through charge interaction to generate chiral transfer or induce self-assembly. The amide bond and urea bond components contained in the molecule enable the regulation of hydrogen bond interaction and hydrophilic-hydrophobic effect by solvents to change the circularly polarized luminescence intensity and direction brought by its aromatic group part.

To provide a method for producing a synthetic resin (X) which can reduce loads on environments when producing the synthetic resin (X).SOLUTION: A method for producing a synthetic resin (X) includes a step of reacting a first raw material (A) synthesized in a step of reacting carbon dioxide with hydrogen, with a second raw material (B) which is synthesized from the carbon dioxide and is different from the first raw material (A). At least one of carbon dioxide for synthesizing the first raw material (A) and carbon dioxide for synthesizing the second raw material (B) contains at least one selected from the group consisting of carbon dioxide which is discharged to the environments and is generated by combustion of an organic matter, carbon dioxide generated by water vapor modification of the organic matter, and carbon dioxide taken out of volcanic gas in geothermal power generation.SELECTED DRAWING: Figure 1

The embodiments herein provide a single-step method for the conversion of a mixture of gases or flue gas containing CO2, N2 and H2O into Urea using plasma as an energy source. The gas mixture is exposed to high voltage AC or DC or pulsed or subjected to radiofrequency electric field to create plasma state of the said gas mixture in the presence of catalysts. The electrical species (ions, radicals etc.) of gases are introduced in electrically activated or ionized water containing solvated electrons, radicals or ions of Hydrogen and other ions or radicals. The Urea is synthesized in such a reducing water media by co-reduction of Amine ions or ions of Nitrogen Oxides, and ions of oxides Carbon. The invention also discloses a method to utilize electrically activated nano-droplets of water to increase the surface area of interaction between a mixture of gases under a plasma field and water. Additionally, the invention discloses that the single-step method disclosed here can also be utilized for synthesizing Ammonia (NH3). The disclosed method can help in the reduction of CO2 emissions from industries or can reduce CO2 concentration in the air.

The invention discloses an ice-cooling type energy-saving vacuumizing system for a urea device. The ice-cooling type energy-saving vacuumizing system comprises a buffer tank, a low-temperature evaporator, a liquid ammonia storage tank and a condensate storage tank which are connected through pipelines. Urea steam in the urea evaporation system passes through the buffer tank through a pipeline and then enters the low-temperature evaporator, the low-temperature evaporator condenses the urea steam, condensate obtained after condensation is discharged into the condensate storage tank, and the condensate is pumped into the urea evaporation system after the condensate storage tank reaches the set liquid level and temperature. Liquid ammonia in the liquid ammonia storage tank is input into the low-temperature evaporator for heat exchange and returns to the liquid ammonia storage tank after heat exchange. The ice-cooling system is adopted, an original steam vacuumizing system is abandoned, the vacuum pump can be directly adopted, steam consumption and sewage discharge are greatly reduced, and the effects of energy conservation and emission reduction are achieved.

The invention discloses a urea compound or an agricultural pharmacologically acceptable salt thereof, an acaricidal composition and application, belonging to the technical field of agrochemistry. The structure of the urea compound is shown as a general formula (I). The acaricidal composition comprises a urea compound or a pesticide pharmacologically acceptable salt thereof as an active ingredient; the urea compound or the pharmaceutically acceptable salt thereof can be used for preventing and treating pest mites in the fields of agriculture, forestry, horticulture or sanitation. The invention has the advantages that a novel urea compound or a pharmaceutically acceptable salt thereof is developed, and the compound still has efficient acaricidal activity at an extremely low dosage.

A plant for producing urea comprises a urea synthesis reactor; a high-pressure device for distilling a urea synthesis solution, consisting of a high-pressure separator and a falling film heat exchanger that constitutes a stripper-distiller; medium-pressure and low-pressure devices for distilling a urea synthesis solution; devices for evaporating a urea solution; devices for condensing and absorbing distillation gases; and means for supplying process streams. Furthermore, means for supplying a urea synthesis solution from the high-pressure separator to the falling film heat exchanger are equipped with a device for regulating the volumetric flow rate, whereas means for supplying a gas phase from the high-pressure separator to a high-pressure device for condensing and absorbing distillation gases do not comprise devices that regulate the volumetric flow rate. Also claimed is a method carried out in the above plant. The result achieved is that of reducing the pressure of ammonia fed into a high-pressure ejector, improving the stripping of the gas phase in the high-pressure separator, reducing the residual boiling of the liquid in the stripper-distiller, reducing corrosion, improving the efficiency of ammonium carbamate decomposition in the stripper-distiller and the operating efficiency of the stripper-distiller, reducing capital costs and providing stable process conditions.