摘要:
Disclosed herein is an efficient, economical, industrially advantageous, straight-through process for the preparation of cyclic amides, also referred as lactams, in substantially pure form and high yield, from the corresponding cyclic ketones and a hydroxylammonium salt, using a combination of amphoteric metal oxide or amphoteric masked metal oxide and a base.
摘要:
A steam stripping device for an inorganic processing solution is provided, which includes a steam stripping unit for heat stripping the inorganic processing solution; a heat exchanging unit coupled to the steam unit for heating the inorganic processing solution; and a desuperheating unit for decreasing the temperature of a steam when overheated before the steam is fed into the heat exchanging unit by cooling liquid. The device can be applied to the inorganic processing solution for removing organic contaminants contained therein. By the provision of the desuperheating unit, the adverse influence on the inorganic processing solution caused by partially superheating can be prevented.
摘要:
The invention relates to a process for the production of cyclohexanone oxime in which a phosphate-containing aqueous reaction medium is cycled from a hydroxylammonium synthesis zone to a cyclohexanone oxime synthesis zone and back to the hydroxylammonium synthesis zone, in which hydroxylammonium synthesis zone hydroxylammonium is formed by catalytic reduction of nitrate with hydrogen, and in which cyclohexanone oxime synthesis zone hydroxylammonium is reacted with cyclohexanone to form cyclohexanone oxime, where the concentration hydroxylammonium in the aqueous reaction medium entering the cyclohexanone oxime synthesis zone is higher than 1.0 mol/l.
摘要:
The present invention relates to a gauze catalyst based on titanium or vanadium zeolites and inert gauze fabrics which is suitable for accelerating oxidation reactions such as epoxidation of olefins, hydrogen peroxide production or hydroxylamine synthesis.
摘要:
The invention provides a stabilized aqueous, semi-aqueous, or non-aqueous solution of hydroxylamine or a partially neutralized hydroxylamine salt and a process therefore. The invention utilizes as a stabilizing agent a specific acetic acid compound.
摘要:
The invention provides a method for purification of hydroxylamine so as to have a substantial reduction of cations and anions. The method involves passing a solution of hydroxylamine through at least one strong acid ion exchange bed which has been pretreated with dilute hydrochloric acid and then through at least one strong base anion exchange resin bed.
摘要:
A process for the preparation of hydroxylammonium salts by catalytic reduction of nitrogen monoxide using hydrogen in the presence of a hydrogenation catalyst, comprises(a) in a first step, filtering the reaction mixture obtained after the reaction, giving a solution of essentially hydroxylammonium salt and a filter residue essentially comprising a mixture of hydrogenation catalyst and a solution of essentially hydroxylammonium salt, and(b) in a second step, subjecting the filter residue to a further separation process in order to concentrate the hydrogenation catalyst, giving a mixture having a higher concentration of hydrogenation catalyst than the filter residue and a mixture having a lower concentration of hydrogenation catalyst than the filter residue.
摘要:
The present invention relates to a multi-step process for producing HAN that is free of ammonium nitrate. The process comprises the steps of: (a) stripping ammonia from an ammonia-containing, aqueous hydroxylamine solution having a hydroxylamine concentration of at least 10% by weight based upon the weight of the hydroxylamine solution, by contacting the ammonia-containing hydroxylamine solution with a stripping agent selected from the group consisting of inert gases and steam to provide an ammonia-free, aqueous hydroxylamine solution, and (b) reacting the ammonia-free, aqueous hydroxylamine solution with aqueous nitric acid having an acid concentration of at least about 0.1%, preferably at least about 20%, based upon the weight of the aqueous nitric acid, to produce ammonium nitrate-free HAN. In another process embodiment of the invention, the above-described ammonia stripping step is not required, and the hydroxylamine concentration is at least about 0.5%, based upon the weight of the reaction mixture employed. Also disclosed is the ammonium nitrate-free HAN product produced by the process of this invention.
摘要:
A hydrogenation catalyst, obtainable by carrying out essentially the following steps:(a) treatment of a platinum metal salt with finely divided sulfur followed by(b) reduction of the platinum metal salt to metallic platinum metal.
摘要:
The present invention relates to an electrochemical process for the removal of excess or residual nitric acid from aqueous hydroxylammonium nitrate (HAN) solutions. The process utilizes a multi-compartment electrochemical membrane cell in which the HAN solution flows through a central ion exchanging compartment bounded by anion membranes on either side. Electrochemically generated OH-ions formed at the cathode are used to displace and remove the nitric acid from the HAN solution. In use, the residual nitric acid content in the HAN is suitably reduced to a specified safe level before the HAN is concentrated to a 13.0 molar final composition.