This article describes a 10-year cooperative effort between the U.S. National Institute of Standards and Technology (NIST) and five major journals in the field of thermophysical and thermochemical properties to improve the quality of published reports of experimental data. The journals are Journal of Chemical and Engineering Data, The Journal of Chemical Thermodynamics, Fluid Phase Equilibria, Thermochimica Acta, and International Journal of Thermophysics. The history of this unique cooperation is outlined, together with an overview of software tools and procedures that have been developed and implemented to aid authors, editors, and reviewers at all stages of the publication process, including experiment
The rate of catalytic decomposition of methanol in the presence of steam has been studied using a commercial Girdler G66B CuO-ZnO low temperature shift catalyst from IS0 to 250°C at atmospheric pressure. The mole ratio of steam to methanol was varied from 0 to 1.5, and the feed rates covered the range from 300 to 1400 kg s/mol. The data were successfully correlated using a simple reaction network involving CH30H, HzO, CO and Hz. A conventional reversible reaction rate equation was used which included a resistance term for site blockage by a CO surface complex. The methanol decomposition rate constants showed satisfactory Arrhenius behaviour with an activation energy of about 96 kJ/mole. On a Ctudit la vitesse de dCcomposition catalytique du mCthanol en prksence de vapeur d'eau, en employant un catalyseur commercial de la rkaction du gaz h I'eau B basse tempkrature (150 ii 250°C B la pression atmosphCrique) Girdler G66B CuO-ZnO. On a fait varier le rapport molaire vapeur d'eau/mCthanol de 0 a 1,s et les vitesses d'alimentation ont variC de 300 a 1400 kg s/mol. On a obtenu une bonne corrklation des rksultats obtenus, en employant une sCrie simple d'ttapes rkactionnelles impliquant CH,OH, H 2 0 , CO et Hz. On a employ6 une Cquation classique pour la vitesse des rkactions rkversibles qui inclut un terme de rksistance pour le blocage des sites par un complexe de surface du CO. Les constantes de vitesse de decomposition du mCthanol suivent bien la loi d'ArrhCnius avec une Cnergie d'activation d'environ 96 kJ/mole. n Part 1 of this paper (Amphlett et al., 1981), the
The thermodynamic equilibria involved in the catalytic steam reformation of methanol to produce hydrogen have been examined over the ranges of pressure 101–3040 kPa, temperature 400–700K and water to methanol feed ratio 1.5–0.67. Four models have been considered based upon possible reaction products and the equilibrium composition of each model calculated.
The presence of methane and carbon reduce the quantity and quality of hydrogen produced. The best condition for hydrogen production occurs at 500K in the model in which carbon (soot) and methane gas are excluded and where pressures are low, and water is in excess in the feed. To achieve these conditions in practice the reactions for methane formation, which is thermodynamically favoured, and the appearance of carbon (soot) must be inhibited.
Abstract:In the proposed new SI, the kilogram will be redefined in terms of the Planck constant and the mole will be redefined in terms of the Avogadro constant. These redefinitions will have some consequences for measurements in chemistry. The goal of the Mole Project (IUPAC Project Number 2013-048-1-100) was to compile published work related to the definition of the quantity 'amount of substance', its unit the 'mole', and the consequence of these definitions on the unit of the quantity mass, the kilogram. The published work has been reviewed critically with the aim of assembling all possible aspects in order to enable IUPAC to judge the adequateness of the existing definitions or new proposals. Compilation and critical review relies on the broadest spectrum of interested IUPAC members.
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