Herein discussed is a method of producing hydrogen comprising introducing a first stream comprising a fuel to an electrochemical (EC) reactor having a mixed-conducting membrane, introducing a second stream comprising water to the reactor, reducing the water in the second stream to produce hydrogen, and recycling at least portion of the produced hydrogen to the first stream, wherein the membrane comprises an electronically conducting phase and an ionically conducting phase; and wherein the first stream and the second stream do not come in contact with each other in the reactor.

The present invention discloses a membrane-less reactor design for microbial electrosynthesis of alcohols from carbon dioxide (CO.sub.2). The membrane-less reactor design thus facilitates higher and efficient CO.sub.2 transformation to alcohols via single pot microbial electrosynthesis. The reactor design operates efficiently avoiding oxygen contact at working electrode without using membrane, in turn there is an increase in CO.sub.2 solubility and its bioavailability for subsequent CO.sub.2 conversion to alcohols at faster rate. The present invention further provides a process of operation of the reactor for biotransformation of the carbon dioxide.

Methods and systems for producing are disclosed. A method for producing iron, for example, comprises: providing an iron-containing ore to a dissolution subsystem comprising a first electrochemical cell; wherein the first anolyte has a different composition than the first catholyte; dissolving at least a portion of the iron-containing ore using an acid to form an acidic iron-salt solution having dissolved first Fe.sup.3+ ions; providing at least a portion of the acidic iron-salt solution to the first cathodic chamber; first electrochemically reducing said first Fe.sup.3+ ions in the first catholyte to form Fe.sup.2+ ions; transferring the formed Fe.sup.2+ ions from the dissolution subsystem to an iron-plating subsystem having a second electrochemical cell; second electrochemically reducing a first portion of the transferred formed Fe.sup.2+ ions to Fe metal at a second cathode of the second electrochemical cell; and removing the Fe metal.

A gas production apparatus including: an electrolysis vessel; first and second electrolyte circulation systems; and an electrolyte exchanger, the first/second electrolyte circulation system including: a first/second circulation tank receiving and storing a first/second electrolyte flowing out from an anode chamber/a cathode chamber; and a first/second circulation pump supplying the first/second electrolyte to the anode chamber/the cathode chamber, the electrolyte exchanger transferring part of the first electrolyte existing in the first electrolyte circulation system into the second electrolyte circulation system on one hand, and transferring part of the second electrolyte existing in the second electrolyte circulation system into the first electrolyte circulation system on the other hand.

Disclosed is a process for preparing adiponitrile from acrylonitrile in an electrolytic cell. An aqueous electrolyte comprising acrylonitrile converts to adiponitrile in the presence of a solid anode and in the absence of a solid cathode. The cathode comprises gas plasma.

The invention relates to an electrolysis arrangement and a method for producing hydrogen and oxygen by electrolysis of an aqueous electrolysis medium, in particular a corrosive electrolysis medium. According to the invention, the electrolyte cooler to maintain the desired operating temperature of the electrolysis cell stack is arranged downstream of the electrolysis cell stack and upstream of the anolyte gas-liquid separator. By this arrangement, less corrosion resistant materials can be used in particular on the anode side of the electrolysis arrangement, since conduits and further components on the anode side of the electrolysis arrangement are exposed to lower temperatures.

Disclosed herein is an improved method of brine water treatment including the removal of calcium and/or magnesium-based hardness utilizing CO.sub.2 mineralization resulting in permanent sequestration of the CO.sub.2 via stable precipitates in conjunction with hydrogen and chlorine production from the electrolysis of brine water.

A system of utilizing carbon dioxide comprises a carbon dioxide capturing device for capturing carbon dioxide, an electrochemical reaction device for producing synthetic gas by reducing the carbon dioxide captured by the carbon dioxide capturing device, a hydrogen carrier manufacturing device for manufacturing a hydrogen carrier material by using the synthetic gas produced by the electrochemical reaction device, a dehydrogenation device for producing hydrogen from the hydrogen carrier material manufactured by the hydrogen carrier manufacturing device, and a hydrogen utilization device for utilizing hydrogen produced by the dehydrogenation device, wherein the dehydrogenation device further produces carbon dioxide from the hydrogen carrier material and supplies the carbon dioxide to the carbon dioxide capturing device.

An electrolytic device and to a method for operating an electrolysis of water with at least one electrolysis cell, the electrolysis cell having an anode compartment having an anode and a cathode compartment having a cathode. The anode compartment is separated from the cathode compartment by a proton exchange membrane. The anode compartment is suitable for holding water and oxidising the water on the anode to form a first product including oxygen and the cathode compartment is suitable for holding water and reducing the water on the cathode to a second product including hydrogen. Furthermore, the electrolysis device includes a first gas precipitation device for precipitation of oxygen, the first gas precipitation device for carrying out a natural water circulation being arranged above the electrolysis cell.

A controller stops flow of posolyte through a positive electrode chamber of a flow cell to trap the posolyte within the positive electrode chamber and hydraulically isolate the flow cell without stopping flow of negolyte through a negative electrode chamber of the flow cell, discharges the flow cell until hydrogen gas is evolved at a reactive surface of the positive electrode chamber while the posolyte is trapped within the positive electrode chamber, and subsequently discontinues the discharge and restarts the flow of the posolyte through the positive electrode chamber.