292 results about "Dehydration reaction" patented technology

The invention belongs to the technical field of perfume preparation processes, and particularly relates to a preparation process of fragrance lasting type perfume ligustral, which comprises the following steps: a catalytic dehydration step: mixing isohexylene glycol and a composite catalyst according to a mass ratio of 100: (0.8-1.2), and carrying out a catalytic dehydration reaction under a gradient heating condition to generate a methyl pentadiene mixture; a Diels-Alder addition step: carrying out an addition reaction on acrolein and a methyl pentadiene mixture according to a mass ratio of 1: (1.05-1.15) under a sectional temperature control condition, controlling the reaction pressure to be 0.25-0.35 MPa, carrying out a heat preservation reaction for 2 hours, and cooling to obtain a ligustral crude product; and a three-tower series rectification step: separating and purifying the ligustral crude product after the addition reaction through a light component removal tower, a middle component removal tower and a refining tower in sequence to obtain a ligustral finished product. By optimizing a catalytic system, reaction conditions and a separation process, the purity and aroma durability of the product are improved.

The invention discloses modified hydroxytyrosol, a cosmetic, a preparation method and application. The provided preparation method of the modified hydroxytyrosol comprises the following steps: in the presence of an acidic solvent, mixing hydroxytyrosol, lipase and fatty acid ester for reaction, centrifugally layering a reaction product, and collecting components of a middle layer to prepare the modified hydroxytyrosol. According to the provided preparation method of the modified hydroxytyrosol, lipase and fatty acid ester are subjected to an enzyme digestion reaction, an active hydroxyl group in a product obtained through the enzyme digestion reaction and hydroxytyrosol are subjected to a dehydration reaction, so that an ester group molecular chain is grafted into hydroxytyrosol, and a modified hydroxytyrosol product with an ester group is prepared. And the obtained modified hydroxytyrosol has relatively high fat solubility and oxidation resistance.

The invention relates to a method for preparing norambrox ether from sclareolide. The method comprises the following steps: 1) preparing a red aluminum toluene solution; 2) dissolving sclareolide with toluene to obtain a sclareolide toluene solution, adding the sclareolide toluene solution into the red aluminum toluene solution for complete reaction, and quenching with a NaCl solution to obtain a reactant containing sclarediol; 3) carrying out oil-water separation on the reactant to obtain a primary organic phase and a water phase, so as to obtain an organic phase containing sclarediol; 4) carrying out a dehydration reaction on the organic phase containing sclarediol by using a molecular sieve, and after the reaction is completed, separating out an organic phase containing norambrox ether; 5, the organic phase containing the norambergyl ether is subjected to distillation concentration and crystallization separation, and a norambergyl ether product is obtained.According to the method, sclareolide is reduced through the red aluminum, and compared with lithium aluminum hydride, hydroboron and red aluminum, the red aluminum has the advantages of being good in stability, beneficial to industrialization, low in reaction temperature and safe.

This invention relates to the field of chemical synthesis technology and discloses a method for preparing 2,5-furandicarboxylic acid from fructose, comprising the following steps: preparing reaction system A containing fructose, an organic bromide, a solid acid catalyst, and water; performing a dehydration reaction to separate the solid acid catalyst and obtain a fructose dehydration reaction solution; preparing reaction system B containing the fructose dehydration reaction solution, a co-oxidant, an oxidation catalyst, and acetic acid; performing an oxidation reaction under an oxidizing gas atmosphere; separating the product to obtain 2,5-furandicarboxylic acid. This invention utilizes a co-oxidant, which can reduce the requirement for fructose concentration in the one-pot preparation of 2,5-furandicarboxylic acid while ensuring the yield and purity of FDCA, thereby improving production efficiency. Furthermore, it reduces or even eliminates the use of hydrobromic acid in the oxidation reaction, thus reducing corrosion to equipment.

The present invention relates to the technical field of alcohol dehydration, and specifically to a catalyst for producing alpha-olefins by dehydrating alcohol, a preparation method thereof, and a method for producing alpha-olefins by dehydrating alcohol. The catalyst comprises: 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-10 wt% of a transition metal oxide; wherein the main component is selected from at least one of Group IVB oxides; and the transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides, and Group IIB oxides. The present invention rationally modifies the catalyst by introducing Group IIA metal elements, Group IIIB metal elements, and Group VIB, VIII, IB, and IIB metal elements into the main component, thereby suppressing carbon deposition of the catalyst in the alcohol dehydration reaction, improving the catalytic performance of the catalyst, and promoting the efficient conduct of the alcohol dehydration reaction to produce alpha-olefins.

The invention discloses a preparation method of titanium dioxide for high-ionic-conductivity battery electrolyte, and relates to the technical field of inorganic material preparation, and the preparation method comprises the following steps: S1, raw material mixing and esterification reaction; s2, reflux reaction and dehydration reaction; s3, neutralizing acidity and carrying out liquid-liquid layering; s4, double distillation purification; s5, performing ultrasonic-assisted dispersion; s6, carrying out sol-gel conversion; s7, carrying out gelation and vacuum drying; s8, performing low-temperature nitrogen presintering; s9, high-temperature oxidation calcination; and S10, performing nanocrystallization and interface modification. Through low-temperature nitrogen presintering and high-temperature oxidation calcination, the low-temperature presintering avoids structural damage, the high-temperature calcination optimizes the crystal performance, the purity, crystallinity and stability are remarkably improved, the high activity and long service life are achieved, and a key material support is provided for the fields of energy, environmental protection and the like.

The application discloses a continuous synthesis method of an amicarbazone intermediate 5-isopropyl-1,3,4-oxadiazole-2(3H)-ketone. The method comprises two continuous processes of hydrazinolysis and phosgenation: continuously feeding a mixture of isobutyric acid and a solvent, a mixture of hydrazine hydrate and a catalyst into a hydrazinolysis continuous reactor respectively, carrying out a warming reflux dehydration reaction, and obtaining an isobutyryl hydrazine solution shown in formula I; continuously feeding the isobutyryl hydrazine solution and phosgene into a phosgenation continuous reactor, carrying out a phosgenation reaction, and after distillation and desolventizing treatment of a reaction solution, obtaining 5-isopropyl-1,3,4-oxadiazole-2(3H)-ketone shown in formula II. The application has the advantages of simple reaction flow, high product yield, and significant production efficiency improvement, and is suitable for industrial large-scale production.

The application discloses a kind of high flame-retardant tpe materials and preparation method thereof, by polytetrahydrofuran, modified monomer and 4,4'-dicyclohexyl methane diisocyanate are reacted, chain extension is used with 1,4-butanediol, finally join flame-retardant additive, form branched structure, and the molecular structure of the pte material is branched structure, and molecular chain segment contains organic silicon composite organic phosphorus structure, when heat decomposition, can generate phosphoric acid, poly-metaphosphoric acid and other acidic substances, these acidic substances will catalyze pte molecule to occur dehydration reaction, accelerate its crosslinking, organic silicon chain segment will produce inorganic silicate or silicon-carbon, and then form a dense carbon layer on the surface of material, can heat insulation and oxygen isolation, prevent combustible gas to escape outward and oxygen diffusion inward, and slow down the further thermal decomposition of internal material, prevent carbon layer from being burnt through or collapse under high temperature, improve the durability of barrier, so that pte material has good flame-retardant effect.

The invention provides a one-step furfural preparation method taking biomass as a raw material, and relates to the technical field of resource utilization of agricultural and forestry wastes. The method comprises the steps of raw material pretreatment, catalytic liquid preparation, hydrolysis dehydration reaction, solid-liquid separation, washing liquid reuse, product purification, catalytic liquid recovery and the like. The reaction is completed by adopting a closed reactor under the condition of not introducing external steam, so that the energy consumption is obviously reduced; the catalytic liquid is formed by compounding sulfuric acid and Lewis acid, so that the reaction efficiency is high; closed circulation of the catalytic liquid and recycling of water resources are realized through rectification and ceramic membrane filtration. The method is simple in process flow, low in pollution emission and suitable for green and efficient bran preparation of various hemicellulose raw materials such as corncobs and straw, the purity of the obtained product can reach 99% or above, and the method has good industrial application prospects.

The application provides a preparation method of high-purity pyromellitic dianhydride, which is prepared from 2,3-dichloromaleic anhydride as raw material, and sequentially subjected to Diels-Alder cycloaddition reaction, elimination reaction and oxidation reaction to obtain high-purity pyromellitic acid, and then subjected to dehydration treatment to obtain high-purity pyromellitic dianhydride. In the preparation method, pyromellitic acid is used as a dehydration raw material to prepare anhydride, so that intermediate acid by-products are not easy to be generated, and the product purity is improved; the dehydration reaction is promoted by adopting azeotropic distillation and separation coupling, so that the reaction yield is improved; the preparation steps are few, the reaction process is simple, the reaction condition is mild, the raw materials are economically inexpensive and easy to obtain; the catalyst or the aid used in each step does not generate harmful substances, and is green and environment-friendly.

The application discloses a preparation method of fluvastatin sodium impurity F, and specifically comprises the following steps: firstly, fluvastatin alcohol ketone is dissolved in an acid solvent to perform a dehydration reaction, then a reduction reaction is performed under the condition of a reducing catalyst, and finally, a hydrolysis reaction is performed with sodium hydroxide to obtain fluvastatin sodium impurity F. The application provides a preparation method of fluvastatin sodium impurity F, which is low in cost, simple in operation, high in yield and easy in process purification. The method uses fluvastatin sodium intermediate (fluvastatin alcohol ketone) as a raw material, the raw material is easy to obtain, and the impurity F can be prepared through only three chemical reactions, and each step does not need a complicated refining process. The fluvastatin sodium impurity F prepared by the application is high in yield and high in purity, and can be used as a standard or control product for quality control and production monitoring of fluvastatin sodium.

The application discloses a catalyst for preparing malononitrile, a preparation method of the catalyst and a method for preparing malononitrile by using the catalyst. The catalyst is a solid catalyst, which is an acidic catalyst loaded with rare earth metal oxide. The method for preparing malononitrile is that cyanoacetic acid or cyanoacetate or cyanoacetamide and an ammonia source are subjected to ammoniation dehydration reaction in a continuous reactor to prepare malononitrile according to a certain molar ratio. Then, vacuum distillation (20 torr-25 torr) is carried out, and a fraction collected at 110 DEG C-120 DEG C is malononitrile product. The ammonia source can be ammonia gas, ammonia water, ammonium carbonate or urea. The method for preparing malononitrile can reduce production cost, improve production safety, reduce the discharge amount of three wastes in the preparation of malononitrile by using an existing process, and improve product quality, and is a sustainable and green synthesis route.

The invention discloses a hydrolysate deacidification-dehydration coupling process and a byproduct recovery method, and belongs to the technical field of hydrolysate treatment. The method comprises the following steps: pretreating a hydrolysate raw material through two-stage filtration; adding the pretreated hydrolysate, a deacidification agent and a dehydration auxiliary agent into a coupling reaction device, and synchronously carrying out deacidification-dehydration reaction under the conditions of 60-120 DEG C and 0.1-0.5 MPa; after the reaction, separating to obtain a deacidification and dehydration product and a mixed solid phase; and dissolving and crystallizing the mixed solid phase to recover high-purity byproducts. The deacidification and dehydration synergistic interaction is achieved, the acidity reduction rate is larger than or equal to 85%, the water content is smaller than or equal to 5%, and the process time consumption is shortened by 28.6%; the byproduct purity is not less than 90%, and the recovery rate is not less than 80 A tail gas treatment system is additionally arranged to ensure that environmental protection reaches the standard. The process is suitable for biomass, polysaccharide and protein hydrolysate treatment, has the advantages of high efficiency, good resource utilization rate and the like, and provides an efficient solution for hydrolysate industrial treatment.

This invention discloses a method for preparing ethylhexylglycerol and its application, comprising the following steps: adding isooctanol and a base to a solvent, stirring and cooling to 0-5 degrees Celsius, then adding a dichloromethane solution of p-toluenesulfonyl chloride dropwise. After the addition is complete, the mixture is brought to room temperature and stirred for a period of time. A sample is taken for gas chromatography analysis until the isooctanol is completely consumed. Water is added to separate the layers, and the dichloromethane layer is collected. The dichloromethane layer is washed twice with water and dried to obtain a dichloromethane solution of isooctyl p-toluenesulfonate, which is then dried and reserved. Glycerol and boric acid are added to a reaction flask for dehydration reaction, and after the reaction is complete, a diglyceride borate intermediate is obtained. The prepared diglyceride borate intermediate is added dropwise to a dichloromethane solution of isooctyl p-toluenesulfonate to obtain isooctyl borate diglyceride ether. Then, the solvent is removed, and the mixture is hydrolyzed with water to obtain the target compound, ethylhexylglycerol. This invention, through the application of the diglyceride borate structure, reduces the generation of by-products, and the overall yield is higher compared with current traditional processes.

This invention relates to the field of organic synthesis technology and discloses a method and system for preparing adiponitrile. The method includes: S1: atomizing molten adipic acid and mixing it with ammonia gas, followed by an ammoniation reaction to generate an ammoniation product; S2: dividing the ammoniation product into two parts, a and b. Part a undergoes a countercurrent, non-contact heat exchange with hot material to generate crude adiponitrile through heating and dehydration, while part b is recycled back to step S1 to participate in the reaction. The ratio of the ammoniation product in part a to that in part b is (1~5):1. The temperature of the hot material is higher than the temperature of the ammoniation product in part a. This invention improves the efficiency of the ammoniation reaction, reduces the decomposition side reactions of adipic acid and the residue of adipic acid, and significantly improves the conversion rate of the dehydration reaction and the selectivity of adiponitrile.

The application discloses a MXene-edge graphene oxide heterojunction / PBO fiber multifunctional heat-conducting composite film and a preparation method thereof. First, MXene and edge graphene oxide (EOG) are subjected to nucleophilic substitution and dehydration reaction to prepare MXene-edge graphene oxide (MEOG) heterojunction fillers, then the fillers are added into a dispersion solution of PBO fibers to prepare an acid gel, the acid gel is replaced by deionized water to prepare a water gel, and finally, the water gel is subjected to heat pressing to obtain the multifunctional heat-conducting composite film. The heat-conducting composite film comprises a PNF substrate and MEOG heterojunction fillers, covalent interaction between the fillers provides an effective way for phonon transmission, hydrogen bond and pi-pi interaction between the fillers and the substrate effectively reduce the interface thermal resistance, and the heat-conducting composite film can be widely used in EMI shielding performance and heat dissipation of electronic devices.

The application discloses a method for efficiently separating and utilizing whole components of wood fiber raw materials, and belongs to the field of wood fiber raw material utilization. The application utilizes a binary solid acid-water solvent system composed of dilute sulfuric acid and salicylic acid to pretreat wood fiber raw materials, so that hemicellulose and lignin in the wood fiber raw materials can be effectively removed at a lower pretreatment temperature, the specific surface area and porosity of the raw materials are improved, and the materials are easy to be hydrolyzed by cellulase, and the materials can be prepared into wood nanofibers after treatment; hemicellulose dissolved in the reaction solution is prepared into furfural through dehydration reaction; and the reaction solution can be recovered into lignin by simple water dilution. Through the combined use of the two groups of solid acids, the lignin is not only effectively separated from the raw materials under the mild conditions, but also selectively degraded hemicellulose, and the lignin is protected, so that the utilization rate of the three components of the wood fiber raw materials is effectively improved.

The invention relates to a biomass low-temperature carbonization accelerant as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out water washing pretreatment on powder obtained by crushing a biomass raw material, and then carbonizing in an inert atmosphere to obtain biomass carbon powder; acidizing the biomass carbon powder to obtain carbon-based solid acid; the carbon-based solid acid and a transition metal salt auxiliary agent are mixed and ground, and the biomass low-temperature carbonization accelerant is prepared. The biomass low-temperature carbonization accelerant is a composite catalyst composed of carbon-based solid acid and transition metal salt; wherein the carbon-based solid acid is used as a main catalytic substrate, provides abundant Bronsted acid loci-SO3H, and is mainly used for catalyzing the dehydration reaction of biomass; transition metal ions are used as Lewis acid sites and generate a synergistic effect with the carbon-based solid acid to jointly catalyze depolymerization, dehydrogenation and aromatization reactions, so that deep carbonization can be initiated and completed at a relatively low temperature of 250-400 DEG C, and the carbonization rate is remarkably higher than that of an existing carbonization catalyst.

This invention discloses a method for preparing the DPP1 inhibitor bresocarte, belonging to the field of pharmaceutical synthesis. Specifically, the method includes the following steps: N-tert-butoxycarbonyl-L-4-bromophenylalanine reacts with methanesulfonyl chloride or 4-nitrobenzenesulfonyl chloride in the presence of a base, followed by amination substitution to obtain intermediate 1; then, it undergoes dehydration in the presence of trifluoroacetic anhydride to obtain intermediate 2; next, it undergoes a coupling reaction with pinacol diboronate to obtain intermediate 3; then, it undergoes a coupling reaction with bromide compound 4 to obtain intermediate 5; then, it undergoes cyclization with di-tert-butyl dicarbonate in the presence of sodium methoxide to obtain intermediate 6; then, it undergoes deprotection in the presence of hydrogen chloride to obtain intermediate 7; next, it undergoes condensation with compound 8 to obtain intermediate 9; finally, it undergoes deprotection in the presence of hydrogen chloride to obtain the inhibitor bresocarte. This method provides a new synthetic approach, with low overall cost, simple operation, high yield, and suitability for industrial production.

The invention relates to a synthesis method of sulfopropionic anhydride. The synthesis method comprises the following steps: (1) mixing 3-bromopropionic acid and sodium sulfite in water, and carrying out sulfonation reaction to obtain a mixture; (2) mixing the mixture with an acidifying agent, and carrying out acidification reaction to obtain 3-sulfonyl propionic acid; and (3) mixing the 3-sulfonyl propionic acid with a dehydrating agent and an organic solvent, and carrying out a dehydration reaction to obtain the sulfopropionic anhydride. According to the invention, compounds such as 3-bromopropionic acid and sodium sulfite are used as reaction raw materials to prepare sulfopropionic anhydride. The method has the advantages of cheap and easily available raw materials, simple operation and high yield, and is suitable for large-scale production.

The invention discloses a nano-particle for inducing death of tumor immunogen cells, a preparation method and application. The preparation method of the nano-particles comprises the following steps: taking a BiOCl nanosheet as a carrier, enabling CeO2 to generate and crystallize in situ on the surface of the BiOCl nanosheet, and forming a BiOC / CeO2 heterojunction; the method comprises the following steps: carrying out a dehydration reaction on NH2-PEG2000-NH2 and DL lipoic acid to synthesize NH2-PEG2000-TA; the preparation method comprises the following steps: reacting NH2-PEG (Polyethylene Glycol) 2000-TA with a Pardaxin peptide of which the carboxyl is activated, so as to generate Pardaxin-PEG 2000-TA; the preparation method comprises the following steps of: coupling Pardaxin-PEG2000-TA (Polyethylene Glycol 2000-TA) and a BiOC / CeO2 heterojunction; the PBCP nanoparticles obtained by the preparation method promote the yield of active oxygen in the endoplasmic reticulum of tumor cells to be increased sharply, so that the endoplasmic reticulum stress is effectively excited, tumor immunogenic cells are induced to die, and the anti-tumor effect is achieved. The nanoparticle can be combined with the existing PD-1 / PD-L1 inhibitor for use, and shows a better anti-tumor effect than the single use of the PD-1 / PD-L1 inhibitor.

The present invention relates to a method for dehydrating isopropanol to produce propylene, a method for producing propylene from acetone as a raw material including the process, and a related production apparatus. The dehydration method of the present invention includes a step of dehydrating a raw material containing isopropanol in the presence of a dehydration catalyst containing alumina to produce a product containing propylene, wherein the water content of the raw material is 0.1-10.0 wt% (, relative to the total mass of the raw material being 100 wt%), and the content of C3-C4 unsaturated impurities in the product is 30 ppm or less. According to the present invention, the production of undesirable by-products can be significantly suppressed while improving the conversion rate of isopropanol.

The invention provides a method for preparing 2, 5-diformyl furan by catalyzing fructose by using an ionic liquid and a vanadium complex, which comprises the following steps: carrying out dehydration reaction by using the fructose as a raw material and the ionic liquid as a reaction solvent and a catalyst to obtain 5-hydroxymethylfurfural, then adding a V / HCP-AQ catalyst, and carrying out oxidation reaction on the 5-hydroxymethylfurfural in an oxygen atmosphere to obtain the 2, 5-diformyl furan. And 3, 5-diformyl furan is obtained. According to the method, the ionic liquid is adopted to replace DMSO to serve as a fructose dehydration and oxidation solvent, ethyl acetate is added into a reaction system for extraction after the reaction is finished, the product 2, 5-diformyl furan can be obtained, and the problem that the product is difficult to separate in the process of preparing the 2, 5-diformyl furan through the fructose one-pot method under a traditional catalytic system is solved.

This application discloses a process for improving the yield of HCN prepared by the Andruse process, belonging to the field of HCN preparation technology. This application utilizes the tail gas after HCN removal and dehydration reactions, using residual methane in the tail gas to increase methane conversion, using CO in the tail gas to inhibit methane decomposition and improve methane selectivity, and using H2 in the tail gas, with H2 combustion providing heat instead of the heat provided by methane decomposition. This improves the conversion rate of methane to HCN, increases the overall reaction yield, and eliminates ammonia residue in the post-reaction gas, saving the ammonia removal step. Simultaneously, it reduces air consumption and increases the ratio of ammonia to methane to oxygen, allowing the reaction to proceed far from the explosion zone, thus improving process safety.

The invention discloses a preparation method for synthesizing 2, 5-furandimethanol (BHMF) from biomass saccharides through a one-pot method based on a water-phase catalysis system, and belongs to the technical field of chemical synthesis. According to the method, in a single water phase reaction system, efficient catalytic conversion is realized through two key steps of integrating biomass sugar dehydration to generate 5-hydroxymethylfurfural (HMF) and biologically reducing HMF to convert into BHMF. Wherein in the dehydration reaction stage, an acid catalyst is adopted, and a polyethylene glycol additive is introduced, so that the yield of HMF is remarkably increased, the generation of by-products levulinic acid and formic acid is effectively inhibited, and the toxic influence of the by-products on thalli in the subsequent reduction stage is reduced; meanwhile, due to the excellent biocompatibility, the inhibition effect on the thallus activity in the whole-cell catalytic reduction process is avoided. The innovative design ensures the continuity and system compatibility of the whole catalytic process, and realizes an efficient and stable catalytic conversion process.

The invention belongs to the technical field of preparation of organic chemicals, and particularly relates to 2-methyl-5-trifluoromethyl furan and a preparation method thereof. The preparation method comprises the following steps: adding a solvent into trifluoroacetone, adding alkali under an ice bath condition, adding 1-chloro-2-methyl ethylene oxide, reacting at room temperature, adding acid, reacting at 40-60 DEG C to complete a dehydration reaction, then adding alkali for aromatization, continuing to complete an aromatization reaction, adding water to extract a reaction system, taking an organic phase, filtering, washing and drying to obtain the 1-chloro-2-methyl ethylene oxide. And rectifying to obtain the 2-methyl-5-trifluoromethyl furan. According to the 2-methyl-5-trifluoromethyl furan and the preparation method thereof provided by the invention, the reaction conditions are mild, the steps are simple, and the prepared 2-methyl-5-trifluoromethyl furan is high in yield and suitable for industrial production.

A process for dehydrating ethanol to ethylene. The steps include: (a) reacting an ethanol feed stream over a dehydration catalyst to produce ethylene in a dehydration product stream; (b) separating said dehydration product stream into a product liquid stream comprising water and dissolved oxygenates and a product vapor stream of ethylene; (c) taking a bypass stream from said product liquid stream; and, (d) sending the bypass stream to the dehydration reactor bypassing a wastewater stripping column.

A process of converting an ethanol feed stream to ethylene comprising sending portions of said ethanol feed stream to two reactors in parallel and then sending the combined product to a third reactor that is operated at a higher temperature to prevent the formation of ethers such as diethyl ether.

The application discloses a kind of phosphogypsum solid waste's step-by-step modification calcination preparation method, belong to solid waste treatment technical field.The method includes: (1) pre-coating treatment: the original state of containing attached water dihydrate phosphogypsum is mixed with composite modifier and is ground, and pre-coated phosphogypsum is obtained;(2) temperature control calcination: the pre-coated phosphogypsum obtained in step (1) is sent into calcining kiln, and dehydration reaction is carried out at 165 DEG C~180 DEG C temperature, and hemihydrate gypsum powder is obtained;(3) hygroscopic aging: the hemihydrate gypsum powder obtained in step (2) is cooled and aged 24h~48h, and the components in powder are used to absorb moisture in air to carry out hydration reaction, and the final product is obtained.The method is free of water washing, short process, and the obtained phosphorus building gypsum standard consistency water consumption is 45%~50%, and 2 hour compressive strength is greater than or equal to 6.5MPa.