Catalytic hydrogenation of cellulose in a straight-chain aliphatic hydrocarbon solvent for converting cellulose to hydrocarbons was investigated. Thermally stable hydrocarbon solvents suppress condensation reactions unlike hydrogen-donor solvents, such as alcohol. In addition, hydrogen transfer from a hydrocarbon solvent to cellulose derived oxygenates is possible when the solvent is used with a hydrogenation catalyst, such as palladium on activated carbon (Pd/C). Moreover, cellulose-derived oil (bio-oil) can be directly used as a transportation fuel without removing the solvent. Although the bio-oil yield is high, the use of Pd/C increases the production cost. Therefore, nickel on activated carbon (Ni/C) was employed as a low-cost catalyst in this study to investigate catalytic hydrogenation of cellulose. In the Ni/C-containing solvent, the cleavage of the C–O bond in cellulose was promoted, resulting in the production of levoglucosan and 5-hydroxymethylfurfural. Similar to Pd/C, the use of Ni/C led to hydrogen transfer from the solvent to oxygenates at >300 °C and the production of cellulose-derived hydrocarbons. However, the hydrocarbon yield decreased when the reaction occurred at 400 °C because the reaction products over-decomposed to hydrocarbon gas and polymerized to heavy oil. Therefore, a reaction temperature of 350 °C was noted to favor the production of cellulose-derived hydrocarbons.

Preliminary experiments were performed to decompose hydrate structures under the high intensity microwave irradiations. When methane hydrate (MH) of about 30 g at a liquid nitrogen temperature (-196 °C) was irra-diated with a microwave of 500 W for 10 seconds, the mass decreased. It can be presumed that this is a mass loss due to the decomposition of MH and the release of methane. Experiments were conducted between -196 °C and -180 °C, although the temperature must be raised to -76 °C to pyrolyze MH. We think that this is the de-composition of microwaves by “work”.

In this study, we evaluated the performance of sol-gel method-deposited titanium dioxide (TiO₂)-based DSSCs with three different organic dyes extracted from hibiscus flower’s foliage, plum and eggplant peels under laboratory conditions (light irradiation of 1 kW/m² and an ambient temperature of 25 °C). As the hibiscus-based dye DSSC exhibited the best stability in terms of maximum electric power output and efficiency, and since humidity in Japan is almost uniform, we decided to test the aforementioned DSSC under real conditions in Morocco -deemed a sunny country with varying weather conditions from one region to another- in terms of output electric currentvoltage characteristics and stability. Besides, and for the sake of comparison with other silicon PV, the performance of a 0.75 Wp m-silicon solar cell was also assessed. The hibiscus flower’s petals-based dye sol-gel DSSC was found to be competitive in terms of output voltage and six times less photocurrent-generative than the silicon one. Also, it was made clear that the DSSC’s stability is function of the evaporation rate of the liquid-state electrolyte (loss of iodine) that strongly depends on the ambient temperature and the relative air humidity.