Hydrogen renewable methods

Zhou, L. 2005. Progress and problems in hydrogen storage methods. Renew Sustain Energy Rev 9 395 08. 

Distributed production of hydrogen from natural gas is another example of a near term solution that helps reduce pollution, while building the infrastructure for renewable hydrogen production methods that are still in development. 

There will be no single pattern of shift towards hydrogen. Some developed and emerging economies will have bigger contributions from nuclear power and coal-based systems. Others will stay closer to tmly renewable methods of power generation [60]. 

The use of a hydrogen transfer method involving methanol provides an efficient alternative to iodomethane or diazomethane that can be applied to the methylation of various substrates through the activation of methanol. Methanol is the simplest of all of the alcohols and represents an abundant bio-based resource and fundamental renewable Cl source [118, 119]. 

Renewed interest in this method came recently from its adaptation to the immobilization of water/ organic solvent biphasic catalysts, resulting in the so-called supported aqueous phase catalysts (SAPCs).117 The molecular catalyst is immobilized via water, which is hydrogen bonded to the surface silanol groups reactants and products are in the organic phase (Figure 11)... 

The new frontiers of hydrogen energy systems described in this paper will be PEM-electrolysis combined with renewable energy sources, biolysis with use of biological methods based on the genetics, and mechanolysis combined with any moving phenomenon and object, in hydrogen production area. 

Generating hydrogen from such waste materials may turn out to be one of the least expensive methods of producing hydrogen since this resource is quite extensive. It has been estimated that in the U.S., roughly 14 quads of the annual 64 quad total energy requirement could be met from renewable biomass sources, which is about 20% of our total energy needs. 

Sewage in vast quantities of billions of gallons per day could be recycled to produce a renewable source of hydrogen. This can be accomplished either by utilizing the non-photosynthetic bacteria that live in the digestive tracts and wastes of humans and other animals, or by pyrolysis-gasification methods. 

CO is derived from a variety of feedstocks such as petroleum gas, fuel oil, coal, and biomass. The industrial scale production of PO starts from propylene, which is mainly obtained from crude oil. However, due to the high importance of this compound, many pathways from renewable sources have additionally been developed [54]. PP is converted to PO by either hydrochlorination or oxidation [55]. The use of chlorine leads to large amounts of salts as by-products, therefore oxidation methods are more important, such as the co-oxidation of PP using ethylbenzene or isobutene in the presence of air and a catalyst. However, this process is economically dependent on the market share of these by-products, thus new procedures without significant amounts of other side-products have been developed, such as the HPPO (hydrogen peroxide to propylene oxide) process in which propylene is oxidized with hydrogen peroxide to give PO and water [56, 57] (Fig. 14). 

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