An integral representation result is obtained for the relaxation of a class of energy functionals depending on two vector fields with different behaviors which appear in the context of thermochemical equilibria and are related to image decomposition models and directors theory in nonlinear elasticity.

Introduction The use of hydrogen as a clean and sustainable fuel depends on an efficient and inexpensive method of producing the gas. Currently, most hydrogen is produced from steam reformation with hydrocarbons, where water splitting (hydrolysis) is performed by reacting steam to carbon-based fuels. To avoid the use of hydrocarbons and greenhouse gas emissions, hydrolysis is also possible thro...

Excessive amount of oxygen content in unprocessed bio-oil deteriorates the quality of bio-oil which cannot be used in transportation vehicles without upgrading. Acetic acid (CH3COOH) is a vital component of ‘acids’ catalogue of unprocessed bio-oil produced from thermochemical conversions of most of biomass feedstocks such as switchgrass, alfalfa, etc. In this study, the decomposition reactions ...

Thermochemical cycles that split water into stoichiometric amounts of hydrogen and oxygen below 1,000 °C, and do not involve toxic or corrosive intermediates, are highly desirable because they can convert heat into chemical energy in the form of hydrogen. We report a manganese-based thermochemical cycle with a highest operating temperature of 850 °C that is completely recyclable and does not in...

Widespread adoption of solar-thermochemical fuel production depends on its economic viability, largely driven by the efficiency of use of the available solar resource. Herein, we analyze the efficiency of two-step cycles for thermochemical hydrogen production, with emphasis on efficiency. Owing to water thermodynamics, isothermal H2 production is shown to be impractical and inefficient, irrespe...

Various methods of water-splitting with use of solar energy are reviewed and compared to each other. Direct thermal method has the highest efficiency, but the difficulty is the heat-resisting materials. Thermochemical method is pro­ mising if the corrosion-resisting materi­ als are found. Electrolytic method is tra­ ditional, but the hybrid system combined with thermochemical and/or photochemic...

The nakhlite Martian meteorites contain alteration mineral assemblages, which reveal detailed information about their formation conditions; Thermochemical modeling allows the assessment of factors not observable in the rocks, such as temperature and fluid chemistry at the time of mineral formation. Combining observation and thermochemical modeling leads to the conclusion that ~4 g CO2 are seque...