Abstract: The present invention relates to an electrochemical cell, system and process for converting essentially anhydrous hydrogen halide to essentially dry halogen gas. The process of the present invention is useful for converting anhydrous hydrogen halide, in particular, hydrogen chloride, hydrogen fluoride, hydrogen bromide and hydrogen iodide, to a halogen gas, such as chlorine, fluorine, bromine, or iodine. In particular, in the present invention, water is provided to the cation-transporting membrane at the cathode in various ways. The present invention allows for recovery of a released fluid at the cathode-side of the membrane and recycling of the released fluid back to the cathode side of the membrane. In this way, the recovered, released fluid may be recycled to continuously supply water to the membrane, thereby allowing the limiting current density of the cell to be increased and/or controlled.

Abstract: Carbonyl halide is produced from carbon monoxide and halogen produced from the electrochemical conversion of anhydrous hydrogen halide. Both the oxidation of anhydrous hydrogen halide and the formation of carbonyl halide are carried out in the anode-compartment of an electrochemical cell. This reduces the equipment and thus the capital investment necessary for carrying out these reactions. Moreover, no catalyst is needed to form halogen and subsequently make carbonyl halide, as in the prior art. In addition, the health hazards associated with making a carbonyl halide, such as phosgene, at high temperatures from chlorinated hydrocarbons with atmospheric oxygen are virtually eliminated. Furthermore, the halogen produced as a result of the oxidation of anhydrous hydrogen halide are dry, thereby eliminating the need for a preheater before the halogen is reacted with carbon monoxide.

Abstract: The present invention relates to an electrochemical cell and a process for producing a hydroxide solution, sulfuric acid and a halogen gas from a hydrogen halide and a sulfate solution. In particular, the sulfate solution may be an alkali metal sulfate solution, such as sodium or potassium sulfate solution, an alkaline earth metal sulfate solution or an ammonium sulfate solution. The cell and the process may use either an anhydrous or an aqueous hydrogen halide, namely, hydrogen chloride, hydrogen fluoride, hydrogen bromide and hydrogen iodide, to a respective dry halogen gas, such as chlorine, fluorine, bromine, or iodine, to produce hydrogen ions in order to split the alkali metal solution and form the sulfuric acid. The cell has two membrane-electrode assemblies, where an anode is disposed in contact with one membrane, and a cathode is disposed in contact with another membrane. The sulfate solution is fed in between the membrane-electrode assemblies.