INTEGRATED METHOD FOR PRODUCING CHLORINE
The invention relates to a process for preparing chlorine in three process steps, wherein a catalytic oxidation of hydrogen chloride to chlorine over a uranium oxide catalyst is performed in a first process step, the chlorine formed is at least partly removed in a second step, and an electrochemical oxidation of hydrogen chloride to chlorine is performed in a third process step.
1 . A process for preparing chlorine from a reaction mixture A comprising at least hydrogen chloride, comprising the steps of
a) oxidizing hydrogen chloride with oxygen to chlorines in at least one first reaction zone in presence of a catalyst to obtain a product stream P 1 ,
b) at least partly removing the chlorine present in the product stream Pi from a) to obtain a product stream P 3 ,
c) electrochemically oxidizing the hydrogen chloride present in the product stream P 3 from b) in a second reaction zone, the product stream P 3 also comprising water, and in some cases also chlorine,
wherein the product stream P 3 from b) is fed directly to the reaction zone in c), and in that the catalyst in a) comprises a uranium compound.
2 . The process according to claim 1 , wherein the catalyst comprises a support material.
3 . The process according to claim 2 , wherein the support material is a uranium compound.
4 . The process according to claim 1 , wherein the uranium compounds are uranium oxides, uranium chlorides and/or uranium oxychlorides.
5 . The process according to claim 4 , wherein the uranium oxides are UO 3 , UO 2 , or UO is, or uranium oxides of a nonstoichiometric composition.
6 . The process according to claim 5 , wherein the uranium oxides of nonstoichioetric composition are those with a uranium to oxygen ratio according to the formula UO x of UO 21 to UO 5 .
7 . The process according to claim 1 , wherein the step a) is conducted at temperatures above 350° C. up to temperatures of 800° C.
8 . The process according to claim 1 , wherein a fractional condensation to obtain the product stream P 3 performed in step b), and from which a product stream P 2 comprising essentially chlorine is removed.
9 . The process according to claim 8 , wherein the heat withdrawn from the product stream P 1 is used for the heating of the reaction mixture A in or upstream of reaction zone of the step a).
10 . The process according to claim 1 , wherein step c) is performed with an oxygen consumption cathode.