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Renewable energy sources have gained increasing importance for mitigating the negative effects of climate change while meeting the globally rising demands for energy. In reality, however, regions where renewable energy sources can be readily tapped are often far away from industrial or urban centers of energy demand, necessitating long distance energy imports. Transmitting electricity over long distances is impractical and costly. Secondary energy carriers such as hydrogen produced through water electrolysis could be a sustainable means to convert renewably generated electricity, e.g., from wind or photovoltaic power plants, to chemical products that can be readily transported and stored. This work compares the environmental impacts of local hydrogen production to its remote production with the associated transport over various distances. We aim to evaluate, if and under which conditions the import of hydrogen is environmentally more favorable than local hydrogen production. It was found that hydrogen produced by water electrolysis powered by renewable energy sources is more climate-friendly than that generated locally by conventional steam methane reforming. Even so, to minimize the global warming impact related to hydrogen production, there is indeed an environmentally relevant trade-off: Balancing the best available local conditions for hydrogen production via renewable sources with the minimum transport distance to the consumers.

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Hydroxy-terminated polyoxymethylene-co-polyoxyalkylene multi-block telechels were obtained by a new methodology that allows for the formal substituting of ether units in polyether polyols with oxymethylene moieties. An interesting feature is that, unlike carbonate groups in polycarbonate and polyethercarbonate polyols, homopolymer blocks of polyoxymethylene moieties can be formed. The regular nature of polyoxymethylene blocks imparts a certain crystallinity to the polymer that can give rise to new properties of polyurethanes derived from such telechels. The synthesis, reaction sequence and kinetics of the formation of oligomeric hydroxy-terminated multi-block telechel polyoxymethylene moieties are discussed in this paper and the preparation of a polyurethane material is demonstrated.