Integrated plants and associated processes for producing ammonia and sulfuric acid have been developed comprising air separation and water electrolysis subsystems and which make surprisingly efficient use of the products from these subsystems (i.e. oxygen and nitrogen from the former and hydrogen and oxygen from the latter). The invention is particularly suitable for use as part of an integrated fertilizer production plant.

The invention relates to polyoxometalates represented by the formula (A.sub.n)m.sup.+[(MR′.sub.t).sub.sO.sub.yH.sub.qR.sub.z(X.sub.8W.sub.48+rO.sub.184+4r)].sup.m− or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal cluster units, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in conversion of organic substrate.

A device for preparing high-purity hydrogen and/or oxygen by electrolyzing water, including an electrolyzer and a degasser for degassing desalted water. The degasser is located at the upstream of the electrolyzer. After desalted water is heated and degassed in the degasser, the content of gaseous impurities, particularly argon, can be reduced to several ppb (weight ratio). The hydrogen and oxygen generated after the desalted and degassed water is electrolyzed in the electrolyzer also contain an extremely small amount of argon, so that the requirements in semiconductor industry are met. Also involved is a method of preparing high-purity hydrogen and/or oxygen by using the device.

A process for preparing a catalytic material of an electrode for electrochemical reduction reactions, said material comprising an active phase based on at least one group VIB metal and an electrically conductive support, which process is carried out according to at least the following steps:

a) bringing water into contact with said electrically conductive support,
b) bringing said wet support into contact with at least one metallic acid hydrate comprising at least one group VIB metal, of which the melting point of said metallic acid hydrate is between 20° C. and 100° C., the weight ratio of said metallic acid to said electrically conductive support being between 0.1 and 4,
c) heating, with stirring, to a temperature between the melting point of said metallic acid hydrate and 100° C.,
d) carrying out a sulfurization step at a temperature of between 100° C. and 600° C.

The present invention relates to an MPC-based hierarchical coordinated control method and device for a wind-hydrogen coupling system. The method comprises the following steps: (1) dividing the wind-hydrogen coupling system into upper-layer grid-connected control and lower-layer electrolytic cell control; (2) controlling grid-connected power to track a wind power prediction curve by adopting an MPC control algorithm for upper-layer grid-connected control, and obtaining an electrolytic cell power control quantity for the lower-layer electrolytic cell control at the same time; (3) dividing operation states of electrolytic cell monomers into four operation states of rated power operation, fluctuating power operation, overload power operation and shutdown; and (4) determining the operation states of various electrolytic cell monomers by adopting a time-power double-line rotation control strategy based on the electrolytic cell power control quantity, thus making the electrolytic cell monomers operate in one of the four operating states in turn.

A direct-current coupling hydrogen production system includes at least one electricity generation system and multiple hydrogen production electrolyzer systems. The electricity generation system includes: a controller, N renewable energy systems, multiple conversion systems and a power switching unit. The power switching unit includes N input ports and M output ports. The controller is configured to control the power switching unit to supply the multiple hydrogen production electrolyzer systems through its output ports with electrical energy received through its input ports, or is configured to control the power switching unit to collect electrical energy received through its input ports and to supply the multiple hydrogen production electrolyzer systems through its output ports respectively corresponding to the hydrogen production electrolyzer systems with the collected electrical energy.

The application describes a method for operating an electrolyzer to generate hydrogen from water using an electrolysis reaction, supplied with power from an AC grid via an actively controlled rectifier circuit. The method includes operating the electrolyzer in a normal operating mode with an input voltage U.sub.EI above a no-load voltage U.sub.LL with predominantly ohmic behavior, operating the electrolyzer in a standby operating mode with an input voltage U.sub.EI below the no-load voltage U.sub.LL with predominantly capacitive behavior, and transitioning from the standby operating mode to the normal operating mode during a first transition duration Δt.sub.1, wherein the first transition duration Δt.sub.1 is reduced by keeping the input voltage U.sub.EI at the electrolyzer input during the standby operating mode above a first voltage threshold value U.sub.TH,1 different from 0 V. The application furthermore describes a connection circuit, an actively controlled rectifier circuit and an electrolysis system for performing the method.

An apparatus for estimating electrical properties of an electrolyzer includes a data processing system for estimating electrical values, for example a membrane resistance, of the electrolyzer based on a difference voltage, a current, and an initial value and an attenuation time constant of a double-layer capacitance voltage of the electrolyzer during a shutdown of the electrolyzer. The difference voltage is a difference between a voltage of the electrolyzer and a total reversible voltage of the electrolyzer. The initial value and the attenuation time constant of the double-layer capacitance voltage are estimated based on values of the difference voltage when the current is zero and thus the difference voltage equals the double-layer capacitance voltage. The electrical values can be estimated even if a stepwise interruption of the current of the electrolyzer is not possible.

The present invention relates to a ruthenium precursor compound, and more particularly, to a ruthenium precursor compound which is for providing ruthenium to an ammonia decomposition reaction catalyst and is represented by Formula C.sub.xH.sub.yO.sub.zN.sub.mRu.sub.n, wherein x is an integer of 3 to 20, y is an integer of 0 to 32, z is an integer of 0 to 20, m is an integer of 0 to 10, and n is an integer of 1 to 3. In addition, the present invention relates to an ammonia reaction catalyst using the ruthenium precursor, and to a method for preparing the ammonia reaction catalyst, and provides an ammonia reaction catalyst having an excellent ammonia conversion rate at low temperatures, thereby being capable of efficient hydrogen production.

An environmental control system employs an electrolysis cell utilizing an anion conducting membrane. A power supply is coupled across the anode and cathode of the electrolysis cell to drive reactions to reduce oxygen and/or carbon dioxide in an output gas flow. A cathode enclosure may be coupled with the electrolysis cell and provide an input gas flow and receive the output gas flow. A first electrolysis cell may be utilized to reduce the carbon dioxide concentration in an output flow that is directed to a second electrolysis cell, that reduces the concentration of oxygen. The oxygen and/or carbon dioxide may be vented from the system and used for an auxiliary purpose. An electrolyte solution may be configured in a loop from a reservoir to the anode, to provide a flow of electrolyte solution to the anode. Moisture from the cathode may be collected and provided to the anode.