Hydrogen high temperature processes

Initially, aluminum chloride was the catalyst used to isomerize butane, pentane, and hexane. Siace then, supported metal catalysts have been developed for use ia high temperature processes that operate at 370—480°C and 2070—5170 kPa (300—750 psi), whereas aluminum chloride and hydrogen chloride are universally used for the low temperature processes. 

Steinfeld et al. [133] demonstrated the technical feasibility of solar decomposition of methane using a reactor with a fluidized bed of catalyst particulates. Experimentation was conducted at the Paul Scherrer Institute (PSI, Switzerland) solar furnace delivering up to 15 kW with a peak concentration ratio of 3500 sun. A quartz reactor (diameter 2 cm) with a fluidized bed of Ni (90%)/Al2O3 catalyst and alumina grains was positioned in the focus of the solar furnace. The direct irradiation of the catalyst provided effective heat transfer to the reaction zone. The temperature was maintained below 577°C to prevent rapid deactivation of the catalyst. The outlet gas composition corresponded to 40% conversion of methane to H2 in a single pass. Concentrated solar radiation was used as a source of high-temperature process heat for the production of hydrogen and filamentous... 

The JAEA selects the IS-process to be the basis for commercial development mainly because it is seen more suited to large-scale nuclear hydrogen production than HTE [9] and other alternatives. However, an available HTE-based plant can be connected to the reactor in the same manner as the IS process plant is connected. The HTE similarly requires a high-temperature process heat, and about 25% of its total energy input is heat and the balance electricity, which are fully and efficiently met in-house by the reactor heat and gas turbine power plant. 

In some applications water-gas-shift (WGS) is coupled with other reactions. For example, the steam reforming of methane to produce hydrogen is one example where both the forward and reverse reaction may be involved. However, this reaction is accomplished at high temperatures and the reaction is usually considered to be at equilibrium at the high temperatures used. In the following these high temperature processes will not be covered only those instances where the WGS reaction is the dominant reaction that is used to produce and/or purify hydrogen is considered. 

Hydrocracking a catalytic high-pressure high-temperature process for the conversion of petroleum feedstocks in the presence of fresh and recycled hydrogen carbon-carbon bonds are cleaved in addition to the removal of het-eroatomic species. 

Work on massive hydrogen production using innovative high temperature processes. 

George R. Hill In the low temperature physical solution process the surface area would probably be that determined by BET adsorption measurements. In the high temperature process, apparently the coal structure is opened up, and the surface would be the total surface of all the molecular units. This occurs, as the dissolution proceeds, by a combination of chemical bond breaking and solvent action with hydrogen transfer to the free radicals produced. 

Hydropyrolysis a short residence time high temperature process using hydrogen. 

Besides the preparation in the liquid phase, silica may also be formed with high temperature processes, using a flame, arc or plasma. One of the most widely used sources of pure silicas is the burning of SiCl4 with hydrogen and oxygen. In the flame the following reactions take place ... 

At the same time, a project for a demonstration platform for validating the production of hydrogen by high-temperature processes and technologies (PROHYTEC) has succeeded in obtaining the financial support of the French authorities of the order of EUR 2 million in 2009. This paper illustrates the objectives, specifications and foreseen deployment of this platform. 

In this work for the first time magnetron sputtering (technologically effective method) was used for the modification of the tubular a-alumina ceramic support of the composite Pd - membrane. This modification could be realized due to the choice of Ni as hydrogen permeable metal instead of y-Al203 layers. It allows to use total effective cross section of the surface porous structure of the support in high temperature process of hydrogen purification by Pd membrane. 

Fig. 21.4. High-temperature processes for generating hydrogen. (Nuclear Hydrogen R D Draft, U.S. Department of Energy, March 2004.)...

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