Chlorine Production by HCl Oxidation in a Molten Chloride Salt Catalyst

Abstract

A molten salt mixture containing 45 mol % KCl and 55 mol % CuCl2 was investigated as a catalyst for the reaction of HCl with O2 to produce Cl2. The HCl conversion for an HCl:O2 molar feed ratio of 1:2 at 450 °C and a total pressure of 1 atm was 80% at a residence time of less than 1 s in a lab scale bubble column reactor. The equilibrium conversion at this temperature and pressure is 84%. The catalyst system was found to remain stable throughout a continuous 24-h experiment. The use of a mixed transition metal/alkali metal molten salt catalyst for HCl oxidation reduces the volatility of supported chlorides and may avoid the mechanical stability limitations of solid catalysts caused by volume changes between the halide and the oxide.

The interaction of CO with a copper(ii) chloride oxy-chlorination catalyst

“…The melting point of copper chloride is 893 K 20 and there is a possibility of molten salt formation with this compound. 9,12 Modification of copper chloride catalysts with group one halides such as potassium is well documented; 9 one reason for the addition is to lower the copper chloride volatility. 9 We have previously used X-ray absorption spectroscopy to investigate the catalyst under consideration here.…”

“…9,12 Modification of copper chloride catalysts with group one halides such as potassium is well documented; 9 one reason for the addition is to lower the copper chloride volatility. 9 We have previously used X-ray absorption spectroscopy to investigate the catalyst under consideration here. 15 XANES measurements recorded on application of a temperature ramp up to a maximum temperature of 640 K showed a decrease in Cu 2+ character and at temperatures from 633 K onwards there was an increasing contribution from Cu + species; at 640 K the sample consisted of a mixture of Cu + and a small amount of Cu 2+ .…”

“…The Deacon reaction is traditionally associated with copper based catalysts, for which the reaction may be described in terms of the following reaction steps: 6,7 2Cu II Cl 2  2Cu I Cl + Cl 2 role for chlorine production by HCl oxidation in a molten chloride salt catalyst. 9 These recycle processes are not widely adopted at this time. Any new phosgene manufacturing process would have to compete with fully developed and deployed processes.…”

Promotion of ZrO2 on RuO2/Al2O3 Catalyst for HCl Catalytic Oxidation: Effect of High Temperature Holding in Nitrogen Atmosphere

“…5,6 Compared with electrolysis and direct oxidation, the catalytic oxidation of HCl to Cl 2 (Deacon process) has been considered to be the most economical route, and the RuO 2 -based catalyst supported on TiO 2 (rutile) or SnO 2 (cassiterite) was one of the current commercialized catalysts. 7,8 The contrast of the effect of support type (TiO 2 , SnO 2 , SiO 2 , Al 2 O 3 , etc.) on the performance of RuO 2 -based catalysts has been previously investigated by researchers.…”

Halogen-Mediated Partial Combustion of Methane in Molten Salts To Produce CO2-Free Power and Solid Carbon

“…In previous work, a single step process for propane oxidative dehydrogenation has been investigated using molten LiI–LiOH. − In this previous process, HI oxidation (reaction 8 ) occurs in the same reactor as hydrocarbon iodination, and only trace carbon oxides were formed due to oxygen’s rapid reaction with LiI (reaction ). Other salts have also been reported as chemical looping catalysts for HX oxidation in separate steps, where a metal oxide (MO) first oxidizes HX to water and a metal halide (MX). ,− The metal halide then reacts with oxygen in a separate reactor to form the halogen and regenerate the metal oxide. Note that reactions –7 are equivalent to reaction 4 when iodine is used; reactions and 4 are equivalent to reaction . …”