摘要:
A process is disclosed for separating a fraction which contains low and medium boiling substances from a mixture of low, medium and high boiling substances. The mixture is treated at the bottom of the distillation column with low boiling vapour, enriching the low boiling vapour with medium boiling substances which can then be extracted at the temperature level of the low boiling substance.
摘要:
The invention concerns a process for the heterogenocatalytic oxidative gaseous phase dehydrogenation of alkyl aromatics or aliphatics (educts) to form the corresponding alkenyl aromatics or olefins. In a first reaction step, the educt is dehydrogenated with a bismuth-containing redox catalyst (oxygen carrier) in the absence of molecular oxygen, and, in a second reaction step, the reduced catalyst is reoxidized with an oxidizing agent. The reaction steps are chronologically or spatially decoupled, and at least one reducible bismuthate (5) on a basic or neutral carrier is used as the bismuth-containing catalyst. The invention further concerns Ba-bismuthate (5) having the composition Ba9Bi3O14 as novel substance.
摘要:
The invention relates to compounds of formula (I): N (A?1R1) (A2R2) (A3R3¿), in which A?1, A2, A3¿, independent of one another, represent alkylene, alkenylene, alkynylene, cycloalkylene and cycloalkenylene, whereby said radicals, independent of one another, can have 1, 2 or 3 substituents that, independent of one another, are selected among alkoxy, hydroxy or keto. At least carbon atom can be substituted by heteroatoms in said radicals, independent of one another. The heteroatoms, independent of one another, are selected among nitrogen, oxygen or sulfur. R?1, R2, R3¿, independent of one another, represent aryl or a 5 or 6-member unsaturated heterocycle with 1, 2 or 3 heteroatoms in the cycle which, independent of one another, are selected among nitrogen, oxygen or sulfur, whereby said radicals, independent of one another, can have 1, 2 or 3 substituents which, independent of one another, are selected among alkyl, alkoxy or hydroxy, with the provision that the sum of the substituents represented by A?1, A2, A3¿ and of the alkoxy and hydroxy substituents represented by R?1, R2, R3¿ is equal to at least 6. The invention also relates to the salts of said compounds.
摘要:
The invention relates to a method for the production of highly pure aqueous solution from free hydroxylamine, wherein the diluted aqueous hydroxylamine solution is concentrated in a column, the vapor containing hydroxylamine is removed from the bottom of the column via a side-stream and highly pure hydroxylamine is obtained through condensation of the vapors. The inventive method is simple and mild, can be used in large-scale production and yields "electronic grade" hydroxylamine.
摘要:
The invention relates to a method for producing an aqueous solution of free hydroxylamine by treating a hydroxylammonium salt with ammonia in the counter-current in a stripping column. As a result, hydroxylamine is released and at the same time, the solution obtained is separated into an aqueous hydroxylamine solution and a salt fraction by distillation. The inventive method is simple and mild, and can be carried out on a large scale. The risk of decomposition is minimal due to the low thermal burden, the low concentration of hydroxylamine and the short residence time involved in the process.
摘要:
The invention relates to a method for producing an aqueous hydroxylamine solution which is substantially free of metal ions. According to said method the hydroxylamine solution is subjected to at least one treatment with an acid cation exchanger.
摘要:
The invention relates to a method for preparing highly stabilised hydroxylamine solutions. According to said method, a starting aqueous hydroxylamine solution is treated for separating anions by means of an anion exchanger which has been fully loaded with a hydroxylamine stabiliser.
摘要:
A process is disclosed for producing an aqueous solution of free hydroxylamine. A solution obtained by treating an hydroxylammonium salt with a base is treated with water or water vapour at a temperature ≥ 80 °C, so as to separate the solution into an aqueous hydroxylamine fraction and a salt fraction. This process is soft and easy to implement on a large scale. The risk of decomposition is minimised because of the low thermal stresses, the low hydroxylamine concentration and the short dwelling time during implementation of the process.