1266 results about "Isomerization" patented technology

The inventive subject matter is directed to compositions and methods for ready-to-inject norepinephrine compositions with improved stability. Most preferably, compositions presented herein are substantially antioxidant free and exhibit less than 10% isomerization of R-norepinephrine and exhibit less than 5% degradation of total norepinephrine.

The invention discloses a bacterial strain for degrading aspartame, a bacterial-algae symbiotic system and application of the bacterial strain and the bacterial-algae symbiotic system, the bacterial strain is corn sphingomonas zeae NCU J1, and the preservation number of the bacterial strain is CCTCC (China Center for Type Culture Collection) NO: M 20251462. And an algal-bacterial symbiotic system is constructed by adopting an oriented symbiotic combination of the corn sphingomonas NCU J1 and the chlorella sp. The corn sphingomonas NCU J1 can metabolize an artificial sweetening agent aspartame and degradation products thereof, metabolism complementation can be achieved through an algal-bacterial symbiotic interface, and bacteria preferentially promote aspartame to be subjected to photohydrolysis to generate degradation products such as diketopiperazine derivatives. The microalgae synchronously start isomerism enzymatic reaction to convert degradation products such as diketopiperazine derivatives into low-toxicity products, the risk of secondary pollution is reduced by 40% or above compared with that of a traditional physical and chemical method, 150 mg / L aspartame can be efficiently degraded within 2 days, generation of derivatives of aspartame can be greatly reduced, secondary pollution is reduced, and the method is suitable for industrial production. And the method has a good application prospect in the aspect of rapidly treating aspartame-containing wastewater.

The invention discloses a system and a method for producing biological aviation kerosene by using waste oil and belongs to the technical field of biological aviation kerosene preparation. The method comprises the following steps: (1) the waste grease and a magnetic catalyst loaded with ionic liquid are mixed and enter a suspended bed pre-hydrogenation reactor for reaction to obtain a pre-hydrogenation product, a carrier in the magnetic catalyst loaded with the ionic liquid is Fe3O4 magnetic particles coated with a silicon dioxide layer, and the ionic liquid is molybdenum-based ionic liquid; (2) separating the pre-hydrogenation product to obtain a primary hydrogenation product; (3) performing hydrogenation upgrading on the primary hydrogenation product to obtain an upgraded intermediate product; (4) separating the upgrading intermediate product to obtain a secondary hydrogenation upgrading product; and (5) carrying out hydroisomerization reaction on the secondary hydrogenation upgrading product to obtain the biological aviation kerosene. According to the method, the magnetic catalyst loaded with the ionic liquid is adopted to catalyze the waste grease, recycling can be achieved under the action of a magnetic field, the catalytic stability is high, and industrial stable production can be achieved without supplementing the catalyst.

This invention discloses a visible-light-responsive dynamically covalently cross-linked self-healing polyurethane and its preparation method, belonging to the field of self-healing materials technology. The material is prepared by reacting diisocyanate, long-chain diol, butanediol, trimethylolpropane, and a monool containing an azophenylboronic acid structure in a certain proportion at 60°C. This invention achieves visible-light-responsive self-healing of the polyurethane material by introducing a visible-light-responsive azophenylboronic acid structure into the polyurethane and utilizing the photoresponsive cis-trans isomerization of the azo structure to regulate the reversible breakage and recombination of the boron-oxygen hexacyclic ring. The visible-light-responsive dynamically covalently cross-linked self-healing polyurethane material prepared by this invention maintains high mechanical strength (16.47 MPa) while exhibiting a strength self-healing efficiency of 95.8% after 8 hours of visible light irradiation, showing broad application prospects in smart materials, anti-corrosion coatings, and other fields.

The invention provides a beta '-sulfo-alpha, beta-unsaturated gamma-lactam derivative as well as a preparation method and application thereof, and belongs to the technical field of organic chemical synthesis. The beta '-thio-alpha, beta-unsaturated gamma-lactam derivative has a structure as shown in a formula I. According to the method disclosed by the invention, cesium carbonate is taken as alkali, and a molecular skeleton of the beta'-thio-alpha, beta-unsaturated gamma-lactam derivative is constructed through free radical coupling and olefin isomerization processes under the condition of blue light irradiation. Bioactivity evaluation shows that the beta '-sulfo-alpha, beta-unsaturated gamma-lactam derivative prepared by the method disclosed by the invention has an inhibition effect on MDA-MB-231 human breast cancer cells.

The invention discloses a shape-selective isomerization catalyst as well as a preparation method and application thereof. The catalyst comprises a ten-membered ring aluminum phosphate molecular sieve, a noble metal active component and a metal oxide auxiliary active component. The ten-membered ring aluminum phosphate molecule is selected from at least one of SAPO-11, MeAPO-11, SAPO-41 and MeAPO-41, and the ten-membered ring aluminum phosphate molecule is selected from at least one of SAPO-11, the noble metal active component is selected from at least one of Pt and Pd; the metal oxide auxiliary agent is selected from at least one of CeO2, Nb2O5 and Ta2O5. Compared with the catalyst prepared in the prior art, the catalyst prepared by the method provided by the invention has higher activity and isomer yield in the isomerization reaction of long-chain n-alkanes.

The invention discloses a genetically engineered bacterium for producing glucuronic acid as well as a construction method and application of the genetically engineered bacterium, and belongs to the technical field of genetic engineering. According to the genetically engineered bacterium for producing glucuronic acid, an inositol oxidase gene MMIOX is integrated on a site of a uronic acid isomerase gene uxaC. According to the invention, an inositol oxidase gene MMIOX is integrated on a genome of a genetically engineered bacterium for producing glucuronic acid, and a uronic acid isomerase gene uxaC is knocked out at the same time, so that the genetically engineered bacterium can efficiently catalyze inositol reaction to generate glucuronic acid through the integrated inositol oxidase gene MMIOX; the glucuronic acid isomerase gene uxaC is knocked out, so that isomerization reaction of glucuronic acid can be avoided, and the yield of glucuronic acid is further increased.

The invention discloses a carbon-based catalyst and a preparation method and application thereof to isomerization of glucose into fructose, the catalyst comprises an active component loaded on a carbon-based catalyst carrier and a chelating agent complexed with the active component, metal salts in the active component are Mg and K, the chelating agent is one or more of citric acid, triacetic acid, triethylamine ethylenediamine and potassium sodium tartrate. The chelating agent adjusts alkali active sites of a reaction system through acidic functional groups of the chelating agent, maintains an acid-base environment required by the reaction, and promotes an isomerization reaction from glucose to fructose. Meanwhile, the chelating agent and the metal ions form a stable complex to prevent metal salt from inactivation, and the metal ions are ensured to be uniformly distributed on the surface of the carrier and prevented from being agglomerated through the dispersity of the chelating agent, so that the activity and stability of the catalyst are improved. By controlling the dosage of the chelating agent and coordination of metal ions, the selectivity of the glucose isomerization reaction and the fructose yield are effectively improved, side reactions are inhibited, and the overall efficiency of the reaction is remarkably improved.

The invention discloses a catalyst for an n-butene isomerization reaction and a preparation method thereof, and belongs to the technical field of catalysts. The preparation method comprises the following steps: mixing a silicon source, an aluminum source, tetrapropylammonium hydroxide and water, adding boric acid, and crystallizing to obtain a seed crystal; the method comprises the following steps: mixing a silicon source, an aluminum source, pyridine and water, adding a seed crystal and ammonium fluoride, and crystallizing to obtain a core-shell type molecular sieve; adding the core-shell type molecular sieve into the bimetallic complex solution for dipping to obtain a metal-loaded type molecular sieve; adding the metal-loaded molecular sieve into a triethyl phosphine ethanol solution for treatment to obtain a phosphorus-modified molecular sieve; uniformly mixing the phosphorus-modified molecular sieve, pseudo-boehmite, sesbania powder and water, kneading, performing extrusion molding, drying and calcining to obtain the catalyst. The catalyst prepared by the invention is used for n-butene isomerization reaction, and has excellent catalytic activity and isobutene selectivity.

The invention discloses a hydrocracking catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier and an active metal component, the carrier comprises a modified Y molecular sieve and aluminum oxide, and the modified Y molecular sieve has the following properties: the crystal particle size is 500 nm or less, the molar ratio of silicon oxide to aluminum oxide is 8-55, the specific surface area is 640-800 m < 2 > / g, the unit cell parameter is 2.433-2.460 nm, and the average pore size is 10-30 nm; the active metal component comprises Mo and a group VIII metal element; the Mo comprises + 5 valence Mo; the group VIII metal element exists in the catalyst in the form of metal phosphide. The catalyst has excellent isomerization performance and aromatic hydrocarbon conversion capability, and is suitable for a hydrocracking process for producing special oil and lubricant base oil.

A process for purifying a crude cis-2-olefine acid by thermal separation, the process comprising subjecting the crude cis-2-olefine acid to wiped-film evaporation or vacuum distillation under a temperature-reduced pressure curve, thereby minimizing the isomerization of the cis-2-olefine acid to trans-2-olefine acid.

The invention belongs to the technical field of biotechnology and biocatalysis, and particularly relates to a method for preparing D-tagatose by catalyzing isomerization of D-fructose. The invention provides a method for preparing D-tagatose by catalyzing isomerization of D-fructose, which comprises the following steps: by taking a wet cell obtained by inducible expression of a recombinant genetically engineered bacterium containing a D-tagatose-4-epimerase gene as a catalyst and D-fructose as a substrate, when the concentration of the substrate is higher than 300g / L, continuously supplementing the substrate and enzyme to prepare the D-tagatose by adopting a strategy of continuously supplementing the substrate and enzyme. The substrate inhibition is reduced, the conversion rate of the D-tagatose is increased, and the final conversion rate of the D-tagatose is increased from 19.5% to 24.2%.

The present disclosure provides a method for more efficiently obtaining HFO-1132(E) and / or HFO-1132(Z) than in conventional methods.The present disclosure specifically provides a method for producing a composition comprising trans-1,2-difluoroethylene (HFO-1132(E)) and / or cis-1,2-difluoroethylene (HFO-1132 (Z)), the method comprising:(x) supplying a starting material gas comprising 1,1,2-trifluoroethane (HFC-143), HFO-1132(E) and / or HFO-1132(Z), and a diluent gas to a reactor containing a catalyst to perform a dehydrofluorination reaction of HFC-143 and an isomerization reaction between HFO-1132(E) and HFO-1132(Z), thereby obtaining a reaction product comprising HFO-1132(E) and HFO-1132(Z), wherein the content of the diluent gas in the starting material gas is 1 to 80 mol %.

The invention provides a hydroisomerization catalyst and an application thereof in an isomerization reaction of n-alkanes. The hydroisomerization catalyst comprises a Ni modified SAPO-11 molecular sieve and an active component loaded on the Ni modified SAPO-11 molecular sieve, the pore diameter of the Ni modified SAPO-11 molecular sieve is 5.4-14.5 nm, the Ni dispersity is 0.31-0.40, and the specific surface area is 195-288 m < 2 > / g.

The invention relates to a method for synthesizing mesitylene by gas-phase non-hydroisomerization of unsym-trimethylbenzene, which comprises the following step of: contacting the unsym-trimethylbenzene with a catalyst under a gas-phase non-hydroisomerization reaction condition in the presence of the catalyst, wherein the catalyst is an EWT structure molecular sieve, the total pore volume of the EWT structure molecular sieve is 0.20-0.51 cm < 3 >. G <-1 >, and the mesoporous volume is 0.11-0.37 cm < 3 >. G <-1 >. According to the method disclosed by the invention, the EWT structure molecular sieve with an ultra-large pore channel structure is adopted as the catalyst, and when the catalyst is used for synthesizing mesitylene through unsym-trimethylbenzene gas-phase non-hydroisomerization, the distribution conditions of raw materials and products are improved, the conversion rate of unsym-trimethylbenzene and the selectivity and the mass yield of mesitylene are improved, heavy component carbon deposition is slowed down, and the yield of mesitylene is improved. The service life of the catalyst is prolonged.

The invention relates to the technical field of biological aviation kerosene, and discloses a process for preparing biological aviation kerosene from waste grease. The method comprises the following steps: introducing waste oil into a hydrofining reactor, introducing hydrogen, carrying out a hydrodeoxygenation reaction under the catalysis of a hydrogenation catalyst, carrying out a reaction on the obtained hydrodeoxygenated oil in an isomerization pour point depressing reactor, and finally carrying out isomerization hot high-pressure separation treatment, isomerization cold high-pressure separation treatment and rectification tower segmentation to obtain the biological aviation kerosene. The specific surface area of a carbon matrix of the hydrogenation catalyst is large, the void structure is rich, a large number of Ni-Mo-P active catalytic centers can be exposed, precious metals such as platinum and ruthenium do not need to be added, the hydrodeoxygenation reaction efficiency of waste oil and fat is remarkably improved, the mass fraction of branched paraffin and cycloparaffin in biological aviation fuel is high, and the combustion performance is better.

The invention provides lubricant base oil and a preparation method thereof, and the preparation method comprises the following steps: carrying out a hydroisomerization reaction on Fischer-Tropsch wax with a distillation range of 400-550 DEG C under the action of a hydroisomerization catalyst, and then carrying out a hydrofining reaction and rectification under the action of a hydrofining catalyst to obtain the lubricant base oil, the preparation method of the hydroisomerization catalyst comprises the following steps: synthesizing a ZSM-48 seed crystal, preparing a ZSM-48 molecular sieve, forming a carrier, loading noble metal ions, roasting and the like. The hydroisomerization catalyst shows high isomerization selectivity for Fischer-Tropsch wax with a distillation range of 400-550 DEG C, and lubricating oil base oil with high viscosity index, low pour point and low cloud point can be prepared from the catalyst under the action of the hydroisomerization catalyst. The method for preparing the lubricant base oil not only has the advantages of high yield and simple preparation process flow, but also can produce high-quality 4cSt base oil and 6cSt base oil at the same time.

The invention relates to the field of catalysts, in particular to a modification method of a molecular sieve catalyst and application of the molecular sieve catalyst in polychlorobenzene isomerization, and the modification method of the molecular sieve catalyst comprises the following steps: (1) carrying out dealumination on the molecular sieve catalyst, and then carrying out first washing and drying treatment; (2) dispersing the catalyst obtained in the step (1) in a metal salt aqueous solution, adding an alkali solution to adjust the pH value of the system to 8-11 for aging, and then carrying out second washing and drying treatment, the mass ratio of the metal salt to the catalyst to water being (0.01-0.15): 1: (4-40), and the mass of the metal salt being metered by the metal amount; (3) dipping the catalyst obtained in the step (2) in an organic sulfonic acid or salt solution thereof, separating, and then carrying out third washing and drying treatment; and (4) roasting the catalyst obtained in the step (3) to obtain the modified molecular sieve catalyst.

The invention relates to the technical field of chemical separation, and discloses an isomerization system and process for 1-butene in etherified C4. Comprising an isomerization reactor, a coalescer, a heat exchanger, a static mixer and a filter, an inlet of the coalescer is connected with an etherified C4 pipeline, an outlet pipeline of the coalescer penetrates through the heat exchanger to be connected with an inlet of the static mixer, the inlet of the static mixer is further connected with a hydrogen pipeline, and an outlet of the static mixer is connected with an inlet of the isomerization reactor. An isomerization reactor outlet is connected with a filter inlet, and a filter outlet pipeline enters the isobutane separation tower. According to the method, 1-butene in etherified C4 is isomerized, and after 1-butene is isomerized into 2-butene by utilizing the relatively small relative volatility of 1-butene and iso-butane and the relatively large relative volatility of 2-butene and iso-butane, the content of 1-butene in the raw material is reduced, the separation difficulty of iso-butane is reduced, and iso-butane with the same purity is obtained; the reflux ratio of the isobutane separation tower can be reduced, and the purpose of saving energy is achieved.

The invention relates to the technical field of chemical engineering, and discloses a catalyst, a preparation method and application of the catalyst in preparation of isopentenal. According to the catalyst for catalyzing isomerization rearrangement of 2-methyl-3-butyne-2-alcohol to prepare isopentenal, provided by the invention, the lanthanide metal oxide is utilized to modify the supported vanadium catalyst, so that the selectivity of the catalyst can be improved, and the yield of isopentenal is increased. According to the synthesis process of the isopentenal, 2-methyl-3-butene-2-alcohol can be isomerized and rearranged into the isopentenal by adopting a reactive distillation mode without using a toxic solvent, efficient and continuous production of the isopentenal is realized, meanwhile, under the catalytic action of the catalyst, the raw material can be converted into the isopentenal with high selectivity, the yield of the isopentenal is increased, and the yield of the isopentenal is increased. And under proper process conditions, hydrogen ions can be provided in the presence of a proper amount of water, so that the raw materials are promoted to be subjected to isomerization rearrangement reaction quickly, the surface temperature of the catalyst is reduced, and the carbon deposition phenomenon of the catalyst is relieved to a certain extent.

A process for producing branched aldehyde intermediates from alpha olefins, and further reacting said branched aldehyde intermediates via hydrogenation reactions, surfactant forming reactions and other chemical derivative forming reactions to produce branched alcohols, branched surfactants and other branched derivatives. A process for producing isomerized olefins, branched aldehydes, branched alcohols, branched surfactants and other branched derivatives through isomerization, hydroformylation, hydrogenation, surfactant forming reactions and other derivative forming reactions.

The invention discloses an organic phosphorescent material intermediate for an OLED (Organic Light Emitting Diode) as well as a preparation method and application of the organic phosphorescent material intermediate, and relates to the field of organic phosphorescent materials. The intermediate is prepared through a Diels-Alder cycloaddition reaction between trans-cyclooctene and 3, 6-diphenyltetrazine, the reaction is carried out under the conditions that the temperature is 20-30 DEG C and the time is 10-30 minutes, and the mass ratio of the trans-cyclooctene to the 3, 6-diphenyltetrazine is 1: (1.0-2.5). Trans-cyclooctene is prepared by isomerizing cis-cyclooctene under the irradiation of 254nm ultraviolet light in the presence of a photosensitizer; the 2, 3, 6-diphenyl tetrazine is prepared by condensation, cyclization and purification of benzaldehyde and benzoyl hydrazine. The purity of the prepared intermediate reaches up to 99.2%, the yield reaches 82.4%, the intermediate serving as an OLED luminescent material has excellent thermal stability, and the quantum efficiency is still kept at 90.1% after HTHH treatment is conducted for 1000 h. The invention provides a new intermediate choice for developing a high-performance OLED (Organic Light Emitting Diode) material.

The invention relates to the technical field of isomerization reaction catalysts, in particular to an isomerization reaction catalyst and a preparation method and application thereof.Sodium metaaluminate, silica sol, sodium hydroxide and hexamethyleneimine are added into distilled water to be stirred and mixed to obtain a reaction mixture, the reaction mixture comprises SiO2, Al2O3, NaOH, HMI and H2O, the reactant mixture is crystallized to obtain a crude product, and the crude product is dried to obtain the isomerization reaction catalyst. Carrying out suction filtration, washing and drying on the crude product to obtain molecular sieve raw powder; the molecular sieve raw powder is roasted and then is subjected to ion exchange by using an ammonium nitrate solution, the isomerization reaction catalyst is obtained after continuous roasting, a proper internal olefin raw material is obtained by using the catalyst in cooperation with isomerization condition control, and ASA synthesized by the internal olefin is excellent in paper sizing performance.

The invention discloses a preparation method of a high-stability photoresponse covalent organic framework membrane and application of the high-stability photoresponse covalent organic framework membrane in selective separation of multiple components. 4-azido azobenzene is prepared by carrying out azido reaction on 4-aminoazobenzene in an acidic aqueous solution, and then a BPTA-TAPB-COF membrane is used as a matrix to prepare the high-stability photoresponse covalent organic framework membrane. 4-azido azobenzene is efficiently grafted to the pore wall of the BPTA-TAPB-COF membrane through a click chemical reaction, the photoresponse covalent organic framework membrane is constructed, and the covalent organic framework membrane can be used for multi-component selective separation and is suitable for multi-component systems with different sizes. The azobenzene group in the pore channel of the prepared Azo-COF membrane is subjected to reversible cis-trans isomerization under the irradiation of ultraviolet / visible light, the response speed is high, and the cycle performance is good; the Azo-COF membrane has good application in the light-operated nanofiltration process, the performance of the Azo-COF membrane is not reduced after the Azo-COF membrane is continuously recycled for 12 days, and the structure of the Azo-COF membrane is kept stable.

The invention discloses a method for preparing high-density aviation fuel by catalyzing turpentine with Bronsted acid. The method comprises the following specific steps: step 1, regulating the strength of Bronsted acid to catalyze the isomerization reaction of terpenoids in turpentine, firstly generating cyclohexene and cyclohexadiene intermediates, and then performing Diels-Alder dimerization addition reaction on the intermediates generated by isomerization under the catalysis of the acid to generate a polycyclic high-density fuel precursor with the carbon number of 20; and 2, carrying out hydrogenation on C = C double bonds in the double-ring structure of the high-density aviation fuel precursor with the carbon number of 20 under the catalysis of a hydrogenation catalyst so as to generate the high-density aviation fuel. The invention provides a novel method for preparing high-density aviation fuel from biomass platform compound turpentine, and the whole preparation process is simple and convenient to operate.

The invention belongs to the technical field of preparation of biological aviation kerosene, and particularly relates to a composite catalyst, a preparation method thereof and a preparation method of the biological aviation kerosene. The isomerization catalyst and the cracking catalyst are combined, the active site of the composite catalyst is optimized, the yield of the biological aviation kerosene and the proportion of isomerization products are increased, the catalyst cost is low, and the technological process is flexible and controllable.

The invention relates to the technical field of C9 heavy aromatics, in particular to a method and device for producing mesitylene from C9 heavy aromatics, and the method comprises the following steps: firstly, in the presence of a catalyst, mixing the C9 heavy aromatics with hydrogen, performing dealkylation isomerization reaction and dehydrogenation separation to obtain a liquid-phase product, and then performing two-stage separation on the liquid-phase product to obtain mesitylene. And mesitylene is produced to the maximum extent. The C9 heavy aromatics are subjected to selective dealkylation and trimethylbenzene isomerization reaction, and the obtained product does not contain propylbenzene, and the content of methyl-ethylbenzene is 1t; the method has the advantages that the yield of mesitylene is more than or equal to 0.2%, the interference of methyl ethyl benzene on the separation of the mesitylene is eliminated, the loss of the mesitylene is small, the one-way yield of the mesitylene is more than or equal to 12%, the reaction process is simple, the mesitylene and unsym-trimethylbenzene products are high in purity, the unsym-trimethylbenzene can be recycled to further increase the yield of the mesitylene, the process is flexible, byproducts are few, the product value is high, and the utilization value of C9 heavy aromatic hydrocarbon resources is obviously improved.

The application provides a continuous hydrogenation-isomerization method capable of meeting the treatment requirements of biological oils, especially waste oils, using a homogeneous hydrogenation process with strong adaptability to raw materials as a raw material pretreatment process, and matching a high-activity nanometer transition metal sulfide catalyst. On this basis, a catalytic distillation process is used for selective cracking of long-chain alkanes to improve the yield of medium and long-chain alkanes; an ultramicro flow hydrogen gas mixer and a reduced non-noble metal hydrogenation-isomerization catalyst are used to reduce the hydrogen / oil ratio and the energy consumption of the circulating hydrogen system, and to reduce the production cost of the catalyst, so as to finally realize efficient and low-carbon conversion of waste oils, and low-cost and high-selectivity preparation of biological aviation kerosene.

The invention provides a nickel metal hydroisomerization catalyst as well as a preparation method and application thereof. The catalyst comprises nickel, an alumina carrier and a molecular sieve, the nickel is loaded on the alumina carrier, and the content of the nickel in the catalyst is 1-10wt%; the molecular sieve is an SAPO molecular sieve. According to the invention, alumina is used as a carrier, non-noble metal nickel is loaded through a wet immersion method and is mixed with the molecular sieve to prepare the alkane isomerization catalyst, so that active metal with smaller particle size and higher dispersity can be provided, metal agglomeration at high temperature is avoided, and the utilization rate of metal is increased; the catalyst with excellent catalytic activity can be obtained only by loading low-content nickel metal, the catalyst has higher catalytic activity and selectivity, the obtained product contains more isomers, and the low-temperature fluidity of the product can be remarkably improved.

The invention provides a preparation method of 2-pentyl-2-cyclopentenone, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: carrying out a first-stage isomerization reaction on 2-pentylidene cyclopentanone and a first composite catalyst in a first atmosphere to obtain an intermediate, carrying out a second-stage isomerization reaction on the intermediate and a second composite catalyst in a second atmosphere, and controlling the volume ratio of nitrogen to hydrogen in the first atmosphere and the second atmosphere to obtain the 2-pentylidene cyclopentanone. In the first-stage isomerization reaction, the conversion rate of converting 2-pentylidene cyclopentanone into 2-pentyl-2-cyclopentenone is increased, and in the second-stage isomerization reaction, the use amount of hydrogen in the second atmosphere is reduced, the temperature of the second-stage isomerization reaction is increased, generation of by-products is inhibited, and the yield of 2-pentylidene cyclopentanone is increased. Further, the yield and the purity of the 2-pentyl-2-cyclopentenone can be improved. According to the preparation method, the first-stage isomerization reaction and the second-stage isomerization reaction are continuous reactions, intermittent reactions are not needed, and the preparation method is more suitable for industrial application.