1,721,107 research outputs found
Co- and Co(Ru)-Based Catalysts for Fischer-Tropsch Synthesis Prepared by High Power Ultrasound
No full textSynthesis of nanostructurated silica-supported cobalt catalyst by acoustic cavitation technique
No full textMercury acetate produced by metallic mercury subjected to acoustic cavitation in a solution of acetic acid in water
No full textHydrogen Bonding of Water in Aqueous Solutions of Trimethylamine-N-oxide and tert-Butyl Alcohol: A Near-Infrared Spectroscopy Study
No full textThe hydration properties of two biologically relevant molecules, trimethylamine-N-oxide (TMAO) and tert-butyl alcohol (TBA), were investigated by monitoring the effects of these two solutes on the near-infrared (NIR) spectra of water. In particular, the 1450-nm v1 + v3 water combination band (v1 is the symmetric stretching and v3 is the asymmetric stretching) and the 1928-nm v2 + v3 band (v2 is the bending) were recorded at 25 °C in aqueous solutions of TBA and TMAO over the 0-0.1 and 0-0.05 solute mole fraction intervals for TBA and TMAO, respectively. NIR data show, in agreement with molecular dynamics simulations and other suggestions found in the literature, that on the whole water molecules are more tightly coordinated by TMAO than by TBA. Furthermore, nonadditive perturbations of the water's H-bond network are observed for TBA and are absent in the TMAO case. These results are discussed in connection to the significantly different action exerted by these two solutes on typical processes governed by hydrophobic interactions, such as protein folding and micellization of a surfactant. In these processes, the data support the assumption that the presence of TMAO or TBA modifies the extent of the free-energy contribution associated with structural reorganization of water
Integration of Solid Oxide Electrolyzer and Fischer-Tropsch: A sustainable pathway for synthetic fuel
Full text linkBecause of their easy and widespread distribution and safe handling, liquid fuels are used in everyday life, to power vehicles, aircrafts, ships, etc. The use of fuels from conventional fossil sources is now called for a more sustainable alternative. Hence, chemical energy storage of electricity generated by renewable sources into synthetic fuels represents an interesting solution, solving also other typical problems with renewables, such as grid stabilization.
Within this framework, the present study deals with the production of synthetic green fuels by means of the Fischer-Tropsch process, downstream a previous electricity-to-gas conversion achieved operating a Solid Oxide Electrolyzer (SOE) stack in co-electrolysis. With reference to the state of the art, this study developed the concept of integrating an SOE and a Fischer-Tropsch process in a small plant size, which is compatible with renewables power density. To this aim, fuel upgrading is supposed to be performed separately.
Based on experimental results on a Solid Oxide Cells stack operated in co-electrolysis, three system-level models were developed, evaluating the most performing option. Thus, considering a plant capacity of 1 bbl/day of liquid fuel, in the best scheme, the electricity-to-liquid efficiency was estimated to be 57.2%. Materials introduced into the system are simply water (33,701 ton/MJ) and carbon dioxide (79,795 ton/MJ). While hydrogen is necessary to feed the SOE, net consumption is zero because it is recovered from Fischer-Tropsch product lighter fraction
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of Support and Synthetic Procedure for Sol-Immobilized Au Nanoparticles
No full textNew gold catalysts supported on CeO2, ZrO2 and TiO2 were synthesized by two different techniques: deposition-precipitation and colloidal method. The role of the surfactant (PVA, PVP, THPC) was also investigated. The catalysts were tested in the oxidation of glucose to gluconic acid, in aqueous environment and under mild conditions (60 °C and atmospheric pressure). TEM and SEM analyses have shown that the small size of gold nanoparticles is a necessary condition, but not sufficient for a good conversion. In fact, for an active sample, we have verified that the excess of surfactant must be removed because it would coat the surface of the catalyst. The surfactant, however, should not be completely eliminated, since it has the fundamental role of stabilizing the sample preventing nanoparticles from aggregation. It was evidenced that both the synthetic approach and the kind of support affect the catalysts’ activity. In fact, by focusing on the three different supports, with all the preparation methods, the ceria has proved to be the best support. This is due to its ability to obtain small gold nanoparticles and to its ability to accumulate oxygen. The most appropriate synthesis methodology proved to be the colloidal method with PVA. Recyclability issue was investigated too
Investigation of Piezoelectret Properties of 3D Printed Foamed Polylactic Acid for Energy Conversion Applications
No full textSonochemical synthesis of nanostructured Co-based catalysts and their application in the Fischer-Tropsch Synthesis (FTS)
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