The article provides a short review on catalyst-based processes for the production of hydrogen starting from methane, both of fossil origin and from sustainable processes. The three main paths of steam- and dry-reforming, partial oxidation and thermo-catalytic decomposition are briefly introduced and compared, above all with reference to the latest publications available and to new catalysts which obey the criteria of lower environmental impact and minimize the content of critical raw materials. The novel strategies based on chemical looping with CO₂ utilization, membrane separation, electrical-assisted (plasma and microwave) processes, multistage reactors and catalyst patterning are also illustrated as the most promising perspective for CH₄ reforming, especially on small and medium scale. Although these strategies should only be considered at a limited level of technological readiness, research on these topics, including catalyst development and process optimization, represents the crucial challenge for the scientific community.

Time-dependent rheological properties and thixotropy of reconstituted debris-flows samples taken from channel bank deposits are examined using a commercial rheometer equipped with a vane rotor geometric system. Sweep tests and creep tests were carried out involving mixtures having different grain concentrations ranging between 50% and 58%. Different initial conditions of the mixtures were considered in order to analyze the effects of aging and rejuvenation (thixotropy) over a short period of time and long period of time. Tested slurries show viscosity bifurcation, yield stress and time-dependent behavior. According to the experimental results, three different regimes were identified: a lower shear rate regime, corresponding to a shear rate lower than the critical value; an intermediate banding shear rate regime characterized by static and dynamic yield stress level; and a higher shear rate regime where the flowing debris behaves as a non-Newtonian fluid characterized by a constant steady state ultimate apparent viscosity. In any case, the initial state of the mixture and the sediment concentration affects the ultimate steady state rheology and the time-dependent (thixotropy) slurries’ behavior.