摘要:
A catalytic process for preparing chlorine from hydrogen chloride, which includes recycle of process streams with reduced accumulation of inert gases in the system is provided. The process includes a step wherein a compressed liquid stream comprising chlorine, carbon dioxide and oxygen is recycled into a column countercurrent to the ascending gas phase and feeding part of the chlorine-rich liquid phase leaving the bottom of the column back into the top of the column. Carbon dioxide present in the ascending gas stream is dissolved out of the gas stream and can later be separated from chlorine without problems by distillation.
摘要:
A process for preparing chlorine by oxidation of hydrogen chloride in the presence of a heterogeneous particulate catalyst by the Deacon process in a fluidized-bed reactor (1), in which the heat of reaction is removed by evaporative cooling by means of water which circulates in the tubes (2) of a shell-and-tube heat exchanger, with the water being fed from a steam drum (4) via a feed line (5) to the tubes (2) of the shell-and-tube heat exchanger at one end of these, being heated in the tubes (2) by uptake of the heat of reaction and partly vaporizing to give a water/steam mixture which at the other end of the tubes (2) of the shell-and-tube heat exchanger is recirculated via a return line (6) to the steam drum (4), wherein the maximum pressure for which the fluidized-bed reactor (1) has to be designed to allow for the event of rupture of a tube (2) of the shell-and-tube heat exchanger is minimized by a valve (7) which in the event of a pressure increase as a result of rupture of a tube (2) closes the feed line (5) and the return line (6) is installed in the feed line (5) and the return line (6) and thereby prevents water flowing from the steam drum (4) into the fluidized-bed reactor (1), is proposed.
摘要:
The invention relates to a process for the work-up of residues from the production of isocyanates, which comprises the steps: a) hydrolysis of the residues by means of water, b) introduction of the reaction product from step a) into a mixer having a heat transfer surface, c) separation of amine and water from the output from step b), d) separation of water and amine.
摘要:
The invention relates to a process for separating hydrogen chloride and phosgene, which comprises bringing a mixture of hydrogen chloride and phosgene into contact with an ionic liquid in which at least part of the hydrogen chloride is dissolved in a step a) and then separating off the hydrogen chloride dissolved in the ionic liquid in a step b).
摘要:
Catalyst comprising ruthenium on a support for the catalytic oxidation of hydrogen chloride by means of oxygen to form chlorine, wherein the catalyst comprises from 0.01 to 10% by weight of silver and/or calcium as dopant.The support preferably consists essentially of alpha-aluminum oxide.The catalyst preferably comprises a) from 0.1 to 10% by weight of ruthenium, b) from 0.01 to 5% by weight of silver and/or from 0.01 to 5% by weight of calcium, c) from 0 to 5% by weight of one or more alkaline earth metals, d) from 0 to 5% by weight of one or more alkali metals, e) from 0 to 5% by weight of one or more rare earth metals, f) from 0 to 5% by weight of one or more further metals selected from the group consisting of nickel, palladium, platinum, iridium and rhenium, in each case based on the total weight of the catalyst.
摘要:
The invention relates to a process for recovering ruthenium from a used ruthenium-comprising catalyst which comprises ruthenium as ruthenium oxide on a support material which is not readily soluble in mineral acid, which comprises the steps: a) the ruthenium oxide-comprising catalyst is reduced in a gas stream comprising hydrogen chloride and, if appropriate, an inert gas at a temperature of from 300 to 500° C.; b) the reduced catalyst from step a) comprising metallic ruthenium on the sparingly soluble support material is treated with hydrochloric acid in the presence of an oxygen-comprising gas, with the metallic ruthenium present on the support being dissolved as ruthenium(III) chloride and obtained as an aqueous ruthenium(III) chloride solution; c) if appropriate, the ruthenium(III) chloride solution from step b) is worked up further.
摘要:
The invention relates to a reactor and a process for preparing chlorine from hydrogen chloride by gas-phase oxidation by means of oxygen in the presence of a heterogeneous catalyst in a fluidized bed, with gas-permeable plates being located in the fluidized bed. The gas-permeable plates are connected in a thermally conductive manner to a heat exchanger located in the fluidized bed.
摘要:
Process for recovering (chloro)hydrocarbon-free hydrogen chloride and phosgene-free (chloro)hydrocarbons from a hydrogen chloride stream comprising (chloro)hydrocarbons and phosgene, which comprises i) in a first step, connecting a first adsorber and a second adsorber in series and passing the fresh hydrogen chloride stream comprising phosgene and (chloro)hydrocarbons firstly through the first adsorber and subsequently through the second adsorber until essentially no more (chloro)hydrocarbon is adsorbed by the first adsorber, ii) in a second step, passing the fresh hydrogen chloride stream through the second adsorber while the first adsorber is regenerated, with essentially phosgene-free (chloro)hydrocarbon being obtained in the regeneration, iii) in a third step, passing the fresh hydrogen chloride steam firstly through the second adsorber and subsequently through the regenerated first adsorber until essentially no more (chloro)hydrocarbon is adsorbed by the second adsorber, iv) in a fourth step, passing the fresh hydrogen chloride stream through the first adsorber while the second adsorber is regenerated, with essentially phosgene-free (chloro)hydrocarbon being obtained in the regeneration, with the steps i) to iv) being able to be carried out one or more times in succession.
摘要:
The invention relates to a process for recovering ruthenium from a used ruthenium-comprising catalyst which comprises ruthenium as ruthenium oxide on a support material which is sparingly soluble in mineral acid, which comprises the steps: a) the catalyst comprising ruthenium oxide is treated in a stream of hydrogen, with ruthenium oxide present on the support being reduced to metallic ruthenium; b) the reduced catalyst from step a) comprising metallic ruthenium on the support material is treated with hydrochloric acid in the presence of an oxygen-comprising gas, with the metallic ruthenium present on the support being dissolved as ruthenium(III) chloride and being obtained as ruthenium(III) chloride solution; c) if appropriate, the ruthenium(III) chloride solution from step b) is worked up further.
摘要:
The invention relates to a reactor and a process for preparing chlorine from hydrogen chloride by gas-phase oxidation by means of oxygen in the presence of a heterogeneous catalyst in a fluidized bed, with gas-permeable plates being located in the fluidized bed. The gas-permeable plates are connected in a thermally conductive manner to a heat exchanger located in the fluidized bed.