The present disclosure relates to a hydrogen gas production method including: a first step of generating a mixed gas containing hydrogen and carbon dioxide from a hydrogen storage agent by dehydrogenation reaction using a catalyst in a reactor; a second step of purifying the generated mixed gas to acquire a gas having a high hydrogen concentration; a third step of separating a solution in the reactor into a solution enriched with the catalyst and a permeate using a separation membrane unit; and a fourth step of supplying the solution enriched with the catalyst to the reactor for reusing in the first step.

In one aspect, the disclosure relates to relates to CO.sub.2-free methods of co-producing hydrogen and solid forms of carbon via methane decomposition. The methods are efficient, self-sustaining, and environmentally sound. In a further aspect, the disclosure relates to recyclable and recoverable catalysts supported by solid forms of carbon and methods for recycling the catalysts. In some aspects, the disclosure relates to catalysts that do not require support by solid forms of carbon. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

In one aspect, the disclosure relates to relates to CO.sub.2-free methods of co-producing hydrogen and solid forms of carbon via methane decomposition. The methods are efficient, self-sustaining, and environmentally sound. In a further aspect, the disclosure relates to recyclable and recoverable catalysts supported by solid forms of carbon and methods for recycling the catalysts. In some aspects, the disclosure relates to catalysts that do not require support by solid forms of carbon. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Producing hydrogen and carbon from hydrocarbons in a single-step process is described. A feedstock including natural gas or other light (e.g., <C5) hydrocarbons is introduced to a plasma reformer. The plasma reformer typically includes a non-thermal plasma. The plasma separates hydrogen from the carbon of the feedstock, yielding H2 and carbon black. The carbon is separated from the H2, and the H2 is further used as fuel (e.g., generating electricity via fuel cell) either contemporaneously or at a later time, stored, pressurized, or dispensed to a vehicle. Excess electricity generated form the H2 is stored in a battery, and excess is either stored or pressurized. Carbon black is further condensed to reduce volume for storage or transport.

Producing hydrogen and carbon from hydrocarbons in a single-step process is described. A feedstock including natural gas or other light (e.g., <C5) hydrocarbons is introduced to a plasma reformer. The plasma reformer typically includes a non-thermal plasma. The plasma separates hydrogen from the carbon of the feedstock, yielding H2 and carbon black. The carbon is separated from the H2, and the H2 is further used as fuel (e.g., generating electricity via fuel cell) either contemporaneously or at a later time, stored, pressurized, or dispensed to a vehicle. Excess electricity generated form the H2 is stored in a battery, and excess is either stored or pressurized. Carbon black is further condensed to reduce volume for storage or transport.

A hydrogen system includes: a compressor that includes an anode, a cathode, and an electrolyte membrane interposed therebetween and generates compressed hydrogen by applying a voltage between the anode and the cathode to move protons extracted from anode fluid supplied to the anode to the cathode; a voltage applicator that applies the voltage between the anode and the cathode; a first flow passage through which a cathode off-gas containing the compressed hydrogen discharged from the cathode is supplied to the anode of the compressor; a first on-off valve disposed in the first flow passage; and a controller that causes the voltage applicator to apply the voltage with the first on-off valve opened during a period of time from startup of the hydrogen system until supply of the cathode off-gas to a hydrogen reservoir is started.

A membrane is described for purifying or separating hydrogen from a multi-component gas stream such as syngas. This membrane uses a molecular pre-treatment, a transition metal, fluorine containing polymer, carbon fibers and carbon matrix sintered on a supportive screen. The membrane may be a bilayer membrane comprised of a layer containing high surface area carbon and another layer containing lower surface area carbon. Methods for purifying hydrogen are also described.

There is provided a membrane comprising: a porous support layer having a first surface and a second surface; a palladium (Pd)-based selective layer on a first surface of the support layer; and a zeolite protective layer on a second surface of the support layer, wherein the support layer is between the Pd-based selective layer and the zeolite protective layer. There is also provided a method of forming the same.

A reforming method may include: reforming a hydrocarbon with steam plasma to generate a first synthetic gas, which includes hydrogen and carbon dioxide, from the hydrocarbon; cooling the first synthetic gas to a predetermined temperature, removing water vapor included in the first synthetic gas, and separating hydrogen from the first synthetic gas; reforming the first synthetic gas, from which hydrogen is separated, and a hydrocarbon with steam plasma to generate hydrogen, and generating a second synthetic gas in which carbon dioxide is decreased; and cooling the second synthetic gas to a predetermined temperature, removing water vapor included in the second synthetic gas, and separating hydrogen from the second synthetic gas.

A high selectivity and high CO.sub.2 plasticization resistant polymer comprises a plurality of repeating units of formula (I) for gas separation applications. The polymer may be synthesized from a superacid catalyzed poly(hydroalkylation) reaction.

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Membranes made from the polymer and gas separation processes using the membranes made from the polymer are also described.