56results about How to "Inhibition of isomerization" patented technology

The invention relates to a process for the production of at least one isomer of xylenes, preferably paraxylene, as well as benzene, starting from a C8-aromatic fraction, whereby said process comprises a zone for separation of xylenes, a zone for isomerization of aromatic compounds with 8 carbon atoms used in the presence of a catalyst that comprises at least one EUO-structural-type zeolite that is selected from among the EU-1, TPZ-3, ZSM-50 zeolites and at least one metal of group VIII of the periodic table, and finally a transalkylation zone of C7- and C9-aromatic compounds. The invention makes it possible to produce paraxylene and benzene with a high yield, starting from a C8-aromatic fraction that comprises a large amount of ethylbenzene with improved performance levels of the isomerization stage and a good conversion of ethylbenzene in the transalkylation stage.

The invention provides a bromination process of star-branched butyl rubber, which comprises the following steps: a) dissolving the star-branched butyl rubber in aliphatic hydrocarbon to obtain a rubber solution; b) mixing the glue solution with a branching agent capturing agent to obtain a mixed solution; c) performing bromination, neutralization and product recovery on the mixed solution to obtain brominated star-shaped branched butyl rubber, wherein the branching agent capturing agent is selected from one or more of ethanol, isopropanol, acetone, methyl ether, cyclohexane, dichloromethane, benzene and methylbenzene. The method is completed by dissolving star-shaped branched butyl rubber in aliphatic hydrocarbon, adding a certain amount of a branching agent capturing agent, adding an oxidant, and carrying out subsequent bromination, neutralization and product recovery; therefore, the residual branching agent in the star-branched butyl rubber can be dissolved before bromination, and isprevented from being combined with an HBr by-product generated in the bromination process, so that the neutralization efficiency is improved, and isomerization conversion from a Type II secondary structure to a Type III primary structure is inhibited.

Disclosed is a bisphosphite represented by the following general formula (I). Also disclosed is a method for producing an aldehyde, which is characterized in that a nonconjugated diene with 6-20 carbon atoms which has a carbon-carbon double bond at an end of the molecule is reacted with carbon monoxide and hydrogen in the presence of the bisphosphite and a group 8-10 metal compound. In the formula, A represents an optionally substituted alkylene group, an optionally substituted cycloalkylene group, an optionally substituted phenylene group or an optionally substituted naphthylene group; and R<1> represents a hydrogen atom or an alkyl group.

The invention relates to a catalyst used for alkylation of methanol, C10 aromatic hydrocarbons and 2-methylnaphthalene for synthesizing 2,6-dimethylnaphthalene, and mainly solves the problems of low conversion rate of the 2-methylnaphthalene, low selectivity of the 2,6-dimethylnaphthalene and low stability of the catalyst in the conventional synthesis process technology. In the technical scheme of the invention, the catalyst comprises the following components in part by weight: 50 to 95 parts of one or a mixture of any two of hydrogen-type silicon-aluminum zeolites, 5 to 50 parts of binder and 1.0 to 15 parts of metal oxide of at least one of transition metal, rare-earth metal and alkaline-earth metal; and the reaction conditions for synthesizing the 2,6-dimethylnaphthalene are that: temperature is between 360 and 500 DEG C, pressure is between 0 and 7.5MPa, the molar ratio of the methanol to the 2-methylnaphthalene is between 1.0 and 3.0, the weight ratio of the C10 aromatic hydrocarbons to the 2-methylnaphthalene is between 1.0 and 6.0, and air speed is between 0.1 and 3.5 hour<-1>. The catalytic reaction ensures relatively high synthesis yield of the 2,6-dimethylnaphthalene, and the problems in the prior art are well solved.

A method for producing a fat by distillation and purification while preventing isomerization. The distillation and purification is conducted under an acidic condition to prevent isomerization.

To provide an azo pigment composition having extremely good hue and extremely good light fastness and showing excellent tinctorial strength (color density) and, preferably, to provide an azo pigment composition further containing an azo pigment having characteristic X-ray diffraction peaks at different positions or a tautomer thereof.

An azo pigment composition which contains at least one azo pigment represented by the following formula (1) and having characteristic peaks at Bragg angles (2θ±0.2°) of 7.2° and 25.9° in X-ray diffraction with the characteristic Cu Kα line, or a tautomer thereof:

The invention relates to the field of production technology researches of natural pigments and in particular relates to a production method for preparing a high-purity lutein crystal from marigold extract. The production method comprises the following steps: adding the marigold extract into a super-critical CO2 extraction tank; carrying out extraction and separation to obtain a raw solution I; adding the raw solution I into a saponification tank containing a saponification solution and stirring until saponification is completely finished, so as to obtain a saponified product I; adding the saponified product I into a stainless steel tank; firstly, adding softened water for washing; then leading a mixed solution into a centrifugal machine and carrying out various times of separation until noliquid is spun out; collecting to obtain a material II; putting the material II into the stainless steel tank and adding a certain amount of absolute ethyl alcohol; stirring until the material and the absolute ethyl alcohol are uniformly mixed, and stopping stirring; standing and recrystallizing at room temperature; leading a crystallized solution into the centrifugal machine and carrying out solid-liquid separation to obtain the lutein crystal; scrapping the lutein crystal into a stainless steel disc; after uniformly dispersing, putting the lutein crystal into a vacuum drying box and dryingto obtain a lutein crystal finished product. According to the production method provided by the invention, the conversion rate from lutein ester to free-state lutein can be effectively improved, and oxidization and isomerization of the free-state lutein are inhibited.

The invention discloses a novel method for terminating allyl alcohol irregular polyether methyl. The novel method comprises the following steps of: adding allyl alcohol irregular polyether raw materials through a material inlet in a jetting loop reactor based on Venturi effect, deoxidizing and introducing inert gases for replacement and protection, and starting an external circulating pump to carry out high-speed jetting mixing; and at a control temperature ranging from 20 DEG C to 70 DEG C, slowly adding a methane chloride raw material and an alkali raw material into the jetting loop reactor through a methane chloride raw material feeding hole and a material feeding hole separately, and the like. According to the novel method disclosed by the invention, this system belongs to a dynamic control system, side reactions are restrained sufficiently, a low-temperature method is further adopted to carry out dynamic reaction control according to the characteristic that activation energy of side reactions is high, hydrolysis reaction of methane chloride is restrained, and isomerization reaction of allyl is further restrained, and therefore, selectivity of a reaction system is higher. Finally obtained allyl alcohol irregular polyether methyl terminated product has color and luster smaller than 30, and has a terminating rate greater than 98%.

A spirally configured cis-stilbene/fluorene hybrid material is shown in formula (1),

R′ is an alkyl group or represented by formula (2),

wherein R₁ to R₄, R₆, R₈ to R₁₁ and R₁₃ to R₁₈ are independently selected from the group consisting of hydrogen atom, halogen atom, cyano group, alkyl group, cycloalkyl group, alkoxy group, amino group, haloalkyl group, thioalkyl group, silyl group and alkenyl group, R₅ is a hydrogen atom, tert-butyl group or aryl group, R₇ and R₁₂ are independently selected from the group consisting of hydrogen atom, aryl group, diarylamino group, cyano group, heteroaryl (e.g., pyridine group, or pyrimidine group).

The invention provides cyanodiphenylethylene compound with stable Z/E configuration in excited state and a preparation method and application thereof. The cyanodiphenylethylene compound with stable Z/E configuration in excited state acts as a novel light-emitting isomer; the structure can be controlled by introducing different push-pull electron groups so as to adjust light emission color and efficiency of the isomer; therefore, the cyanodiphenylethylene compound has a very promising application prospect in the fields, such as photoluminescence, piezochromism and fluorescent sensing.

The invention relates to a catalyst for carbon dioxide hydrogenation and toluene aromatic ring alkylation as well as a preparation method and application of the catalyst. The catalyst is prepared by mixing a Cu-based catalyst and an HZSM-5 molecular sieve. The Cu-based catalyst is a mixed oxide composed of a Cu body and modified metal, and the mass ratio of the Cu-based catalyst to the surface HZSM-5 molecular sieve is 1: 3 to 3: 1. The modified metal is one of Zr, Zn, Ce and Ti, the content of the Cu oxide is 50 wt%-95 wt%, and the content of the modified metal is 5 wt%-50 wt%. Compared with the prior art, the method has the advantages that the methanol-to-olefin side reaction caused by an improper methanol/toluene feeding ratio can be reduced, and the production efficiency of xylene is improved; meanwhile, the isomerization reaction of xylene can be inhibited, and the selectivity of p-xylene in the product is improved; and the catalyst has good stability at a high temperature, provides a new idea for carbon dioxide hydrogenation and toluene aromatic ring alkylation, and has a good industrialization prospect.

The invention relates to compound water dispersible granules and a preparation method thereof. The compound water dispersible granules at least comprise gibberellic acid GA<4+7>, 28-epihomobrassinolide and an auxiliary agent, wherein under the condition that the mass of the gibberellic acid GA<4+7> is smaller than that of the 28-epihomobrassinolide, the mass ratio of the gibberellic acid GA<4+7> to the 28-epihomobrassinolide is 1: 12.5 to 1:50; the auxiliary agent comprises at least one of a sodium methylnaphthalene sulfonate-formaldehyde condensate, sodium methylene dinaphthalenesulfonate andsodium lignin sulfonate; the ratio of the mass of the gibberellic acid GA<4+7> and the 28-epihomobrassinolide to the mass of the auxiliary agent is 1: 2 to 1: 10; the ratio of the auxiliary agent inthe ratio of the mass of the gibberellic acid GA<4+7< and the 28-epihomobrassinolide to that of the auxiliary agent increases along with increase of the ratio of the gibberellic acid GA<4+7> to the 28-epihomobrassinolide.

The invention provides a method for detecting lactulose in a dairy product. The method comprises the steps of adding beta-D-galactosidase into a dairy product sample, carrying out an enzymatic hydrolysis reaction on lactose and lactulose to generate galactose, fructose and glucose, respectively carrying out an oximation reaction on galactose, glucose and fructose and methoxylamine, and carrying out a derivatization reaction on the generated reactants and N-methyl-N-trimethylsilane trifluoroacetamide to finally obtain a test solution. The test sample solution is analyzed by adopting an ultra-high performance liquid chromatography tandem mass spectrometer to obtain the content of lactulose. The method can accurately and sensitively determine the content of lactulose in pasteurized milk.

Disclosed is a Grignard reagent and aryl halide coupled alkyl introduction method by metal catalysis. According to the invention, commercialized or easily prepared aryl halide Ar-X is selected as a main raw material, wherein Ar is phenyl ring or C4-C8 heterocyclic benzenoid and X is I or Br or Cl. A final product Ar-R is obtained by coupling of the Grignard reagent RMgX with the aryl halide, wherein Ar is phenyl ring or C4-C8 heterocyclic benzenoid, X is I or Br or Cl, and R is C1-C5 alkyl or C3-C6 cycloalkyl. The raw materials used in the synthetic method are all cheap and easily available. The chemical conditions are mild. During the whole production process, the method is simple to operate, is a feasible synthetic technology with low pollution, and provides a novel thinking and method for the preparation of alkyl aromatics.

An ester derivant having a crystal structure in which the molecules in two adjacent molecule planes are antiparallel is created from a carboxylic acid having carbon-carbon double bond and a compound having a functional group that can react to a carboxyl group of the carboxylic acid. The crystal of the ester derivant is then subjected to light irradiation or heating.

The invention discloses a method for preparing a benzaldehyde catalyst through catalytic oxidation of benzyl alcohol. The method comprises the following steps: taking La2O3@COF, epoxypropane, hydrochloric acid, deionized water, absolute ethyl alcohol, La2O3, benzidine and anhydrous THFA as main raw materials, preparing La2O3@COF aerogel particles by adopting a supercritical CO2 drying technology,preparing wet gel by adopting a simple sol-gel method, and preparing the aerogel particles with uniform pores and high specific surface area by adopting the supercritical drying technology. Accordingto the method disclosed by the invention, the preparation process is novel, raw material cost is low, application range is wide, a normal pressure drying method can be used, a supercritical drying process can also be used, and the obtained catalyst has excellent catalytic performance on the oxidation reaction of benzyl alcohol.

A separation method and system for a byproduct 2M2BN in a course of producing 3PN by 2M3BN isomerization. The present invention proposes that in the course of producing 3PN by 2M3BN isomerization, a byproduct 2M2BN is produced, and 2M2BN will continuously accumulate in the system to suppress the isomerization reaction. The relative volatility of 2M2BN and 2M3BN is increased by using an extractant of the present invention, and separation of 2M2BN and 2M3BN and recycle of the extractant are completed in one distillation column with a partition plate, so that the equipment cost and difficulty are greatly reduced, and 2M2BN and 2M3BN products with high purity can be obtained.

A process of preparing an alkoxylation catalyst wherein a catalyst precursor which is formed from an alkoxylated alcohol, calcium hydroxide, carboxylic acid, inorganic acid, and propylene oxide, is mixed with an antioxidant, preferably butylated hydroxyl toluene. A process of alkoxylation using the catalyst of the present invention.

The purpose of the present disclosure is to purify hexafluorobutadiene to a high purity while inhibiting the isomerization of hexafluorobutadiene. A method for purifying hexafluorobutadiene, said method comprising a step for contacting a composition containing hexafluorobutadiene with zeolite having an SiO2/Al2O3 ratio of 4.0-8.0.

The invention relates to a method for detecting aluminum ions in cells by long wave emission fluorescence imaging. A fluorescent probe L is adopted as a fluorescent imaging probe for detecting trace Al<3+> in cells by fluorescent imaging, trace Al<3+> in cells is detected by long wave emission fluorescence imaging, and the chemical structural formula of the fluorescent probe L is shown in the formula. The formula is shown in the description. During detection, a fluorescent probe L solution is first used for culturing cells, so that the fluorescent probe L gets into the active cells, the activecells with the fluorescent probe L are then cultured along with Al<3+>, so that the probe reacts with Al<3+> in the active cells to produce a compound which can emit fluorescence with a characteristic wavelength, realizing the imaging of Al<3+> ions dyed by the probe in the active cells, and a laser confocal fluorescence microscope is used for observing the fluorescence image of the cultured active cells. The method has the advantages that: the method has high selectivity and good sensitivity, trace Al<3+> in cells can be detected by fluorescence imaging under a long emitted wavelength, moreover, the tissue-penetrating capability is high, and light-induced injury and background fluorescence self-interference are prevented.