Abstract:
The invention relates to a method for the catalytic oxidation of hydrogen chloride with oxygen to form chloride in a fluidized bed method in the presence of a catalyst containing ruthenium on a particulate carrier made of alpha-aluminum oxide having an average particle size of 10 to 200 µm, characterized in that the catalyst carrier has a low surface roughness and can be obtained from a used catalyst, which has been used for at least 500 operating hours in a fluidized bed method.
Abstract:
A process is proposed for preparing chlorine by oxidizing hydrogen chloride in the presence of a heterogeneous particulate catalyst by the Deacon process in a fluidized bed reactor (1), wherein the heat of reaction is removed by evaporative cooling with water which circulates in the tubes (2) of a shell and tube heat exchanger, wherein the water is supplied from a steam drum (4) via a feed line (5) to the tubes (2) of the shell and tube heat exchanger at one end thereof, it heats up in the tubes (2) by absorbing the heat of reaction and evaporates partly to obtain a water/steam mixture which is passed back into the steam drum (4) via a return line (6) at the other end of the tubes (2) of the shell and tube heat exchanger, which is characterized in that the maximum pressure for which the fluidized bed reactor (1) has to be designed for the event of fracture of a tube (2) of the shell and tube heat exchanger is minimized by introducing a valve (7) into the feed line (5) and into the return line (6), said valve (7), in the event of a pressure rise owing to the fracture of a tube (2), blocking the feed line (5) and the return line (6), thus preventing water from flowing out of the steam drum (4) into the fluidized bed reactor (1).
Abstract:
The invention relates to a method for recovering ruthenium from a spent ruthenium-containing catalyst which contains ruthenium in the form of ruthenium oxide on a support material that is poorly soluble in mineral acid. Said method comprises the following steps: a) the catalyst containing ruthenium oxide is reduced in a gas stream containing hydrogen chloride and an optional inert gas at a temperature ranging from 300 to 500°C; b) the catalyst that has been reduced in step a) and contains metallic ruthenium on the poorly soluble support material is treated with hydrochloric acid in the presence of a gas containing oxygen such that the metallic ruthenium on the support is dissolved in the form of ruthenium(III) chloride and is recovered in the form of aqueous ruthenium(III) chloride solution; c) if necessary, the ruthenium(III) chloride solution obtained in step b) is further processed.
Abstract:
The invention relates to a method for regenerating a hydrogen chloride oxidation catalyst containing ruthenium oxide on a support material. Said method comprises the steps of a) reducing the catalyst using a gas stream containing hydrogen chloride and an optional inert gas at a temperature ranging from 100 to 800°C, b) recalcining the catalyst using a gas stream containing oxygen at a temperature ranging from 150 to 800°C.
Abstract:
The invention relates to a method for producing chlorine in a fluidized bed reactor, a gaseous reaction mixture containing hydrogen chloride and oxygen flowing from the bottom to the top of a heterogeneous particulate catalyst that forms a fluidized bed. The invention is characterized in that said fluidized bed comprises insertion elements which divide the fluidized bed into a plurality of horizontal and vertical cells arranged in the fluidized bed reactor, the walls of said cells being permeable to gas and having openings for ensuring the exchange of particles of the heterogeneous particulate catalyst in the vertical direction in the range of between 1 and 100 liter(s)/hour per liter of reactor volume.