Abstract:
The present invention provides a method for preparing amides, in which an amino acid ionic liquid is used as both a reaction medium and a catalyst to catalyze Beckman rearrangement of a ketoxime, so as to produce an amide. In the method, the rearrangement is conducted by catalyzing a ketoxime with an amino acid ionic liquid having the asymmetric property at a moderate reaction temperature during a short reaction time, so as to produce an amide without adding other catalysts such as concentrate sulfuric acid. The method has advantages such as avoiding corrosion in equipments with pipelines, the high conversion rate of ketoximes and the high selectivity of amides.
Abstract:
The present invention provides a catalyst composition for preparing an amide, including an amino acid ionic liquid having a cation of formula (I) and an anion selected from the group consisting of an inorganic acid group, an organic acid group and a combination thereof, wherein the numbers of the anion and the cation are such that the amino acid ionic liquid is electroneutral; and a Bronsted acid. The present invention also provides a method for preparing an amide in the presence of the catalyst composition, and the method has advantages such as decreasing viscosity of ionic liquid, and increasing conversion rate of ketoximes and selectivity of amides.
Abstract:
The present invention provides a titanium-silicalite molecular sieve and a method for preparing the same. The method includes the steps of preparing a mixture of a titanium source, a silicon source, a transition metal source, a template agent and water; heating the mixture to form a gel mixture; heating the gel mixture in a water bath; and calcining the gel mixture after the gel mixture in the water bath to form the titanium-silicalite molecular sieve. The present invention further provides a method for preparing cyclohexanone oxime by using the titanium-silicalite molecular sieve as the catalyst which results in high conversion rate, high selectivity and high usage efficiency of hydrogen peroxide.
Abstract:
The present invention provides a method for preparing an amide. The method includes the steps of performing in a reactor including a catalyst composition having a nitrogen-containing heterocyclic compound and sulfuric acid Beckman rearrangement of a ketoxime to form a product stream having the amide, wherein a molar ratio of the nitrogen-containing heterocyclic compound to the sulfuric acid is from 1:1 to 1:8; and separating an organic phase having the amide and an aqueous phase having the catalyst composition from the product stream. The present invention facilitates the regeneration of the catalyst composition with low water content, so as to increase the conversion rate of a ketoxime and the selectivity of an amide.
Abstract:
Provided is a method for manufacturing hydroxylamine. In this method, an aqueous reaction medium containing acidic buffer agent and nitrate ions in the presence of a limited amount of metal impurities such as Fe or Cu is introduced into a hydroxylamine synthesis reactor in the presence of catalyst to proceed hydroxylamine synthesis by reduction of nitrate ions with hydrogen gas as reducing agent in the aqueous reaction medium to produce hydroxylamine. The reaction is processed in the aqueous reaction medium with a limited amount of metal impurities or even without metal impurities, such that the selection rate of the hydroxylamine product is increased.
Abstract:
The present invention provides a method for preparing an amide. The method includes the steps of performing in a reactor including a catalyst composition having a nitrogen-containing heterocyclic compound and sulfuric acid Beckman rearrangement of a ketoxime to form a product stream having the amide, wherein a molar ratio of the nitrogen-containing heterocyclic compound to the sulfuric acid is from 1:1 to 1:8; and separating an organic phase having the amide and an aqueous phase having the catalyst composition from the product stream. The present invention facilitates the regeneration of the catalyst composition with low water content, so as to increase the conversion rate of a ketoxime and the selectivity of an amide.
Abstract:
The present invention provides a method for preparing large particles of titanium-silicalite molecular sieves. The method of the present invention includes the steps of preparing a dispersion solution of a primary crystalline molecular sieve; forming an aggregated particle solution by adding a flocculating agent and a coagulating agent into the dispersion solution; mixing the aggregated particle solution with a synthesis gel to form a mixture; and heat-treating the mixture. The average diameter of the titanium-silicalite molecular sieves in the present invention is more than 5 μm. In the preparation of cyclohexanone oxime using the molecular sieve of the present invention as the catalyst, the selectivity and conversion rate of cyclohexanone oxime are high, the usage of hydrogen peroxide is enhanced, and the catalyst is easy to be recovered.
Abstract:
The present invention provides a method for preparing amides, in which an amino acid ionic liquid is used as both a reaction medium and a catalyst to catalyze Beckman rearrangement of a ketoxime, so as to produce an amide. In the method, the rearrangement is conducted by catalyzing a ketoxime with an amino acid ionic liquid having the asymmetric property at a moderate reaction temperature during a short reaction time, so as to produce an amide without adding other catalysts such as concentrate sulfuric acid. The method has advantages such as avoiding corrosion in equipments with pipelines, the high conversion rate of ketoximes and the high selectivity of amides.
Abstract:
This invention provides a catalyst composition for preparing hydroxylamine, which comprises palladium, a platinum compound, a germanium compound and a carrier, wherein a halogen concentration of the composition is no more than 10 ppm. The catalyst composition is prevented from poisoning by halogens, and therefore the catalyst composition has high selectivity and catalytic activity. Further, the weight ratio of palladium and platinum in the catalyst composition ranges from 100:1 to 1000:1, such that the catalyst composition can be used to solve the commonly observed problem, i.e., decreased selectivity due to the excessive amount of platinum.
Abstract:
A method for preparing hydroxylamine, comprising the steps of: (i) pretreating the acidic buffer solution with the compounds having a functional group represented by formula (I), thereby removing metal impurities from the acidic buffer solution; and (ii) reducing nitrate ions in the acidic buffer solution with hydrogen to give hydroxylamine in the presence of catalysts, According to the present invention the selectivity for reducing nitrate ions to give hydroxylamine can be significantly enhanced.