US 12,391,557 B2
Method for producing phosgene
Torsten Mattke, Ludwigshafen am Rhein (DE); Gerhard Olbert, Ludwigshafen am Rhein (DE); Jochen Gauer, Ludwigshafen am Rhein (DE); Kai Thiele, Antwerp (BE); Koenraad Vandewalle, Antwerp (BE); Jens Ferbitz, Ludwigshafen am Rhein (DE); and Peter Van Den Abeel, Antwerp (BE)
Assigned to BASF SE, Ludwigshafen am Rhein (DE)
Appl. No. 17/605,737
Filed by BASF SE, Ludwigshafen am Rhein (DE)
PCT Filed Apr. 14, 2020, PCT No. PCT/EP2020/060433
§ 371(c)(1), (2) Date Oct. 22, 2021,
PCT Pub. No. WO2020/216648, PCT Pub. Date Oct. 29, 2020.
Claims priority of application No. 19171148 (EP), filed on Apr. 25, 2019.
Prior Publication US 2022/0212936 A1, Jul. 7, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 32/80 (2017.01); C25B 1/34 (2006.01); C25B 15/08 (2006.01); C25B 1/46 (2006.01)
CPC C01B 32/80 (2017.08) [C25B 1/34 (2013.01); C25B 15/08 (2013.01); C25B 1/46 (2013.01)] 13 Claims
 
1. A process for preparing phosgene comprising
a) providing a chlorine feed stream having a content of chlorine oxides of not more than 130 ppm by volume, wherein
i) chlorine is prepared by electrolyzing an aqueous solution of sodium chloride under conditions under which chlorine is obtained with a chlorine oxide content of not more than 130 ppm by volume, or
ii) chlorine having a chlorine oxide of more than 130 ppm by volume is subjected to a workup by which the content of chlorine oxides is reduced to a value of not more than 130 ppm by volume, or
iii) a first chlorine gas stream having a chlorine oxide content of more than 130 ppm by volume is mixed with a second chlorine gas stream having a chlorine oxide content of less than 130 ppm by volume in such a ratio as to result in a chlorine feed stream having a content of chlorine oxides of not more than 130 ppm by volume, or
iv) the chlorine is prepared by using a process other than the electrolysis of an aqueous solution of sodium chloride in which chlorine with a chlorine oxide content of not more than 130 ppm by volume is obtained,
b) subjecting the chlorine feed stream provided in step a) to a catalytic reaction with carbon monoxide over an activated carbon catalyst in at least one reactor.