Provided is a carbon dioxide recovery device including an absorption part that produces a compound of carbon dioxide and an amine contained in an absorbing solution, and a regeneration part that includes an anode that desorbs the carbon dioxide from the compound to produce a complex compound of the amine, and a cathode that is electrically connected to the anode and regenerates the amine from the complex compound.

The invention relates to an electrolysis arrangement for alkaline electrolysis and a method for producing hydrogen and oxygen by electrolysis of an alkaline electrolysis medium. According to the invention, an anolyte deaerating means is arranged downstream of an anolyte gas-liquid separator and is arranged upstream of the electrolysis cell stack of the electrolysis arrangement, and/or a catholyte deaerating means is arranged downstream of a catholyte gas-liquid separator and arranged upstream of the electrolysis cell stack of the electrolysis arrangement. By this arrangement, the fact is exploited that many undesirable gas components have a much lower solubility in the alkaline electrolysis medium than in pure deionised water, which is supplied as fresh water to the electrolysis arrangement for compensation of the water consumed by the electrochemical reaction.

The disclosure relates in its first aspect to a process of conversion of a gaseous stream comprising methane into hydrogen (51) and carbon (25), the process is remarkable in that it comprises a step (a) of providing a first gaseous stream (3, 7); a step (b) of bromination and synthesis in which the first gaseous stream (3, 7) is put in contact with a second stream (53) comprising bromine resulting in the formation of a third stream (15) comprising methyl bromides and hydrogen bromide, and of a fourth stream (25) comprising carbon including graphite and/or carbon black; a step (c) of separation performed on the third stream (15) to recover a hydrogen bromide-rich stream (41) which is then oxidized in a step (d) to produce a stream (51) comprising hydrogen. The second aspect relates to the installation for performing the process of the first aspect and the third aspect concerns the use of bromine in such process.

An electrolytic reactor comprises at least one electrolytic cell with an anode compartment and a cathode compartment separated by a separator, in particular a semipermeable membrane. The anode compartment comprises an inlet and an outlet for anolyte at opposed ends, said inlet and outlet being connected with each other via an anolyte circulation pipe equipped with a storage means for anolyte, an anolyte vessel and at least one adsorption filter for adsorbing molecular impurities. When molecular impurities comes from the cathode compartment through the separator, the electrolytic reactor acts also as a cleaning device for the catholyte.

Disclosed is a method for synthesizing β-cyano ketone compound, including steps of (1) adding a α-keto acid and sodium hydroxide to a separator-free electrolytic cell, adding acetonitrile thereto, and dissolving the α-keto acid and sodium hydroxide in acetonitrile by stirring to be uniform, to obtain a dissolution solution; (2) adding an alkene or a derivative thereof, cyanobenziodoxolone, and an electrolyte to the dissolution solution, to obtain a mixed solution; (3) subjecting the mixed solution to an electrochemical reaction by electrifying a cathode of a platinum sheet, and an anode of a graphite electrode to obtain a reacted solution; and (4) after the electrochemical reaction, collecting the reacted solution, adding water thereto and stirring to obtain a mixture, subjecting the mixture to an extraction to obtain an organic phase, drying the organic phase and purifying, to obtain the β-cyano ketone compound.

The invention relates to an electrolysis arrangement for the production of hydrogen and oxygen by alkaline electrolysis. The electrolysis arrangement includes a system configuration which enables to balance the lye concentrations between the anode and cathode section of the arrangement depending on the current density of the direct current supplied to the electrolysis stack of the electrolysis medium. At high current densities, hydrogen to oxygen crossover and oxygen to hydrogen crossover is low, which allows full mixing of electrolysis media to balance the concentration between anolyte and catholyte. At low current densities, hydrogen to oxygen crossover and oxygen to hydrogen crossover is high. Therefore, the electrolysis arrangement is configured so that the mixing of the electrolysis media is decreased in case a current density of a direct current supplied to the electrolysis stack is decreased.

The invention relates to a method for producing a gas product containing oxygen, wherein a feedstock containing water is subjected to electrolysis to obtain a raw anode gas, which is rich in oxygen and contains hydrogen, and a raw cathode gas, which is low in oxygen and rich in hydrogen. The raw anode gas is at least partially subjected to a catalytic conversion of hydrogen to water to obtain a first mixture with depleted hydrogen content. A first part of the first mixture is returned to the raw anode gas downstream of the electrolysis and upstream of the catalytic conversion, and the gas product containing oxygen is formed using at least a second part of the first mixture. The invention also relates to a plant for carrying out a method of this type.

A method for operating a system for electrolysis in order to obtain at least one gaseous electrolysis product, in which system at least one electrolysis device is electrically connected to a power converter by means of a direct-voltage circuit, the power converter being connected to an alternating-voltage circuit in order to supply the at least one electrolysis device with electrically energy for the operation of the at least one electrolysis device, the power converter being operated by means of zero crossing control. The invention further relates to a system of this type.

The invention relates to a method (100) for the electrolytic production of a liquid hydrogen product (4), in which a water-containing feed is subjected to an electrolysis (E) while receiving an anode raw gas (3), rich in oxygen and containing hydrogen, and a cathode raw gas (2) which is depleted of oxygen and rich in hydrogen, wherein the cathode raw gas (2) downstream of the electrolysis (E) is subjected to a purification (R), a compression (K), and a liquefaction (L), characterized in that the cathode raw gas (2) at least partially undergoes intermediate storage (Z) downstream of the electrolysis (E) and upstream of the liquefaction (L). A corresponding installation is also proposed.

A method of producing hydrogen using a water electrolysis system comprising at least an electrolyzer and a purifier for removing oxygen in a hydrogen gas generated in the electrolyzer. The method includes controlling a concentration of oxygen in a hydrogen gas to be introduced to the purifier to be constantly less than 0.5 volume % when the electrolyzer is operated at least under a current density of 0.5 kA/m.sup.2 or greater; and further controlling Ob/Oa to be less than 10.0, where Oa represents the concentration of oxygen in the hydrogen gas to be introduced to the purifier when the electrolyzer is operated under a current density of 2.0 kA/m.sup.2, and Ob represents the concentration of oxygen in the hydrogen gas to be introduced to the purifier when the electrolyzer is operated under a current density of 0.2 kA/m.sup.2.