Economic Assessment of the Hydrogenation of CO₂ to Liquid Fuels and Petrochemical Feedstock

To remove high concentrations of CO2 from the off-gas of coal-driven power plants, a new process was proposed. The catalytic hydrogenation of the CO2 leads to the production of C2 – C4 (petrochemical feedstock) and liquid C5+ hydrocarbons (fuel). Thus, environmentally harmful CO2 may be converted sustainably to useful products. On the basis of a process flow sheet, the costs for processing the CO2 are estimated for different plant sizes. The price of hydrogen contributes significantly to the overall production costs. Further price reductions may be achieved by final engineering optimization of the process as a whole and specific unit operations

Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO2_2

Altermagnets are an emerging third elementary class of magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of timereversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism, but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO$_2$ by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic-structure basis for a family of novel phenomena and functionalities in fields ranging from topological matter to spintronics, that are based on the unconventional time-reversal symmetry breaking in altermagnets

Induced pseudoscalar coupling of the proton weak interaction

The induced pseudoscalar coupling $g_p$ is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling $g_p$ has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of $g_p$, the experimental studies of $g_p$, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

Catalyst Development for CO₂ Hydrogenation to Fuels

New active and selective catalyst compositions for the hydrogenation of CO2 to mainly fuel-type higher hydrocarbons were developed by application of an evolutionary strategy. It was shown that Fe and K supported on TiO2 and modified by Cu plus other modifiers resulted in highest selectivity for C5–C15 hydrocarbons at high degrees of CO2 conversion. Co containing catalysts were less suited since they produced methane and light hydrocarbons with high selectivities. A detailed study of reaction conditions showed that selected catalyst compositions were able to reach high CO2 conversion with still low selectivities to methane at higher reaction temperatures and a higher H2/CO2 ratio. conversion with still low selectivities to methane at higher reaction temperatures and a higher H2/CO2 ratio

Optimierung der Reaktionsfuehrung heterogen katalytischer Umsetzungen. Teilprojekt Abschlussbericht

SIGLEAvailable from TIB Hannover: F02B1727 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany); Forschungszentrum Juelich GmbH (Germany). Projekttraeger Neue Materialien und Chemische Technologien (NMT)DEGerman