The present disclosure relates in its first aspect to a process of converting a stream comprising methane into chemicals, said process being remarkable in that it comprises the steps of providing a first stream (1, 5, 11) comprising methane, providing a second stream (79) which is a bromine-rich stream, putting into contact said first stream (15) with said second stream (79) to obtain a third stream (21) comprising at least unreacted methane, methyl bromide, dibromomethane, and hydrogen bromide and removing said dibromomethane from said third stream (21), to produce a dibromomethane stream (103) and a fourth stream (27) comprising unreacted methane, methyl bromide and hydrogen bromide; wherein the fourth stream (27) is converted into chemicals. In its second aspect, the present disclosure concerns an installation for carrying out the process of the first aspect.

The present disclosure relates in its first aspect to a process of converting a stream comprising methane into chemicals, said process being remarkable in that it comprises the steps of providing a first stream (1, 5, 11) comprising methane, providing a second stream (79) which is a bromine-rich stream, putting into contact said first stream (15) with said second stream (79) to obtain a third stream (21) comprising at least unreacted methane, methyl bromide, dibromomethane, and hydrogen bromide and removing said dibromomethane from said third stream (21), to produce a dibromomethane stream (103) and a fourth stream (27) comprising unreacted methane, methyl bromide and hydrogen bromide; wherein the fourth stream (27) is converted into chemicals. In its second aspect, the present disclosure concerns an installation for carrying out the process of the first aspect.

A process for recovering gold from a gold-containing raw material, comprising leaching the gold-containing material with an aqueous solution comprising elemental bromine and bromide source to form a pregnant leach solution with the gold dissolved therein; separating said pregnant leach solution from the gold-depleted raw material, removing elemental bromine from said pregnant leach solution, extracting the gold from the pregnant leach solution in an acidic environment into an organic extractant, to form a gold-loaded extract and bromide-containing raffmate, stripping the extract with an alkaline aqueous solution to form a gold-bearing aqueous solution, generating gold (Au.sup.0) and treating bromide-containing stream(s) to produce recyclable elemental bromine.

An electrolysis system is provided in some embodiments of the present disclosure, including an anode reaction chamber, a cathode reaction chamber and a spacer. The anode reaction chamber includes an anode reaction solution and an anode immersed in the anode reaction solution, in which the anode reaction solution includes an iodide ion, and a material of the anode includes a carbon material. The cathode reaction chamber includes a cathode reaction solution and a cathode immersed in the cathode reaction solution, in which the cathode reaction solution includes a hydrogen ion. The spacer separates the anode reaction chamber and the cathode reaction chamber, in which the spacer allows a cation or an anion to pass through, so that the anode reaction chamber and the cathode reaction chamber are electrically connected to each other.

An electrolysis system is provided in some embodiments of the present disclosure, including an anode reaction chamber, a cathode reaction chamber and a spacer. The anode reaction chamber includes an anode reaction solution and an anode immersed in the anode reaction solution, in which the anode reaction solution includes an iodide ion, and a material of the anode includes a carbon material. The cathode reaction chamber includes a cathode reaction solution and a cathode immersed in the cathode reaction solution, in which the cathode reaction solution includes a hydrogen ion. The spacer separates the anode reaction chamber and the cathode reaction chamber, in which the spacer allows a cation or an anion to pass through, so that the anode reaction chamber and the cathode reaction chamber are electrically connected to each other.

There is provided a new type of electro-synthetic (electrochemical) or electro-energy cell, such as a fuel cell. The cell includes a liquid electrolyte and at least one gas diffusion electrode (GDE). The GDE operates as a gas depolarized electrode and includes a gas permeable material that is substantially impermeable to the liquid electrolyte, as well as a porous conductive material provided on a liquid electrolyte facing side of the gas diffusion electrode. The porous conductive material can be attached to the gas permeable material by being laminated. Alternatively, the porous conductive material is deposited or coated on at least part of the gas permeable material. A depolarizing gas can be received by the at least one gas diffusion electrode to gas depolarize the electrode. The depolarizing gas changes a half-reaction that would occur at the gas diffusion electrode to a half-reaction that is energetically more favorable.

Electrochemical systems and methods for producing hydrogen. Generally, the systems and methods involve providing an electrochemical cell that includes an anolyte compartment holding an anode in contact with an anolyte, wherein the anolyte includes an oxidizable substance having a higher standard oxidation potential than water. The cell further comprises a catholyte compartment holding a cathode in contact with a catholyte that includes a substance that reduces to form hydrogen. Additionally, the cell includes an alkali cation conductive membrane that separates the anolyte compartment from the catholyte compartment. As an electrical potential passes between the anode and cathode, the reducible substance reduces to form hydrogen and the oxidizable substance oxidizes to form an oxidized product. The pH within the catholyte compartment may be controlled and maintained to a value in the range of 6 to 8. Apparatus and methods to regenerate the oxidizable substance are disclosed.

Electrochemical systems and methods for producing hydrogen. Generally, the systems and methods involve providing an electrochemical cell that includes an anolyte compartment holding an anode in contact with an anolyte, wherein the anolyte includes an oxidizable substance having a higher standard oxidation potential than water. The cell further comprises a catholyte compartment holding a cathode in contact with a catholyte that includes a substance that reduces to form hydrogen. Additionally, the cell includes an alkali cation conductive membrane that separates the anolyte compartment from the catholyte compartment. As an electrical potential passes between the anode and cathode, the reducible substance reduces to form hydrogen and the oxidizable substance oxidizes to form an oxidized product. The pH within the catholyte compartment may be controlled and maintained to a value in the range of 6 to 8. Apparatus and methods to regenerate the oxidizable substance are disclosed.

The present invention relates to a method for producing a hexafluoromanganate(IV), said method being characterized by comprising: inserting an anode and a cathode into a reaction solution that contains a compound containing manganese having an atomic valence of less than 4 and/or manganese having an atomic valence of more than 4 and hydrogen fluoride; and then applying an electric current having an electric current density of 100 to 1000 A/m.sup.2 between the anode and the cathode. According to the present invention, it becomes possible to produce a hexafluoromanganate(IV) in which the content ratio of manganese having an atomic valence of 4 is high and the contamination with oxygen is reduced and which has high purity. When a complex fluoride red phosphor is produced using the hexafluoromanganate(IV) as a raw material, the phosphor produced has high luminescence properties, particularly high internal quantum efficiency.

A method and/or electrochemical cell for utilising one or more gas diffusion electrodes (GDEs) in an electrochemical cell, the one or more gas diffusion electrodes have a wetting pressure and/or a bubble point exceeding 0.2 bar. The one or more gas diffusion electrodes can be subjected to a pressure differential between a liquid side and a gas side. A pressure on the liquid side of the GDE over the gas side does not exceed the wetting pressure of the GDE during operation (in cases where a liquid electrolyte side has higher pressure), and/or a pressure on the gas side of the GDE over the liquid side, does not exceeds the bubble point of the GDE (in cases where the gas side has the higher pressure).