Abstract: The present invention relates to an electrochemical cell and a process for using a halogen halide and splitting a sulfate solution and producing a hydroxide solution, sulfuric acid and a halogen gas. 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 sulfate 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.

Abstract: The invention relates to an electrochemical cell which has an electrode, which may be either an anode or a cathode, and a membrane disposed in contact with one side of the electrode. An anode current bus is disposed on the other side of the anode, and a cathode current bus is disposed on the other side of the cathode. An anode current distributor collects current from an anode current bus and distributes it to the anode by electronic conduction, and a cathode current distributor collects current from the cathode and distributes it to the cathode bus by electronic conduction. The anode or the cathode current distributor is made of a metal which is treated by either nitriding, boriding or carbiding the metal in order to make the metal oxide growth resistant. Alternatively, the current distributor on the cathode side may be made of a nickel-based alloy. The current distributor thus provides a barrier between the current bus and the electrode, and the anolyte, catholyte and products of the cell.

Abstract: The invention relates to an electrochemical cell which has an electrode, a membrane disposed in contact with one side of the electrode and a mass flow field disposed on the other side of the electrode for directing fluid to and away from the electrode. The mass flow field comprises glassy carbon. The cell of the present invention is particularly useful in converting anhydrous hydrogen halide, in particular, hydrogen fluoride, directly to essentially dry halogen gas, such as dry fluorine gas. Alternatively, the cell may be used to convert an aqueous reactant.

Abstract: A particular anode comprising an electrochemically active material selected from the group consisting of the oxides of the elements tin, germanium and lead and mixtures comprising at least one of the respective oxides of such elements is useful in an electrochemical cell for the direct production of essentially dry halogen gas from essentially anhydrous halogen halide, or in a process for such production of essentially dry halogen gas. This cell or process may be used to produce halogen gas such as chlorine, bromine, fluorine and iodine from a respective anhydrous hydrogen halide, such as hydrogen chloride, hydrogen bromide, hydrogen fluoride and hydrogen iodide.

Abstract: The invention relates to a process for electrochemically converting anhydrous hydrogen halide, such as hydrogen chloride, hydrogen fluoride, hydrogen bromide and hydrogen iodide, to essentially dry halogen gas, such as chlorine, fluorine, bromine and iodine gas, respectively. In a preferred embodiment, the present invention relates to a process for electrochemically converting anhydrous hydrogen chloride to essentially dry chlorine gas. This process allows the production of high-purity chlorine gas. In this process, molecules of essentially anhydrous hydrogen chloride are transported through an inlet of an electrochemical cell. The molecules of the essentially anhydrous hydrogen chloride are oxidized at the anode of the cell to produce essentially dry chlorine gas and protons, which are transported through the membrane of the cell. The transported protons are reduced at the cathode to form either hydrogen gas or water.