Synthesis and Characterization of NiMo Catalysts Supported on Fine Carbon Particles for Hydrotreating: Effects of Metal Loadings in Catalyst Formulation

The by-products collected during the synthesis of carbon nanohorns via the arc discharge synthesis method is comprised of other carbon particles (OCP). At a hydrotreating operating temperature of 370°C, preliminary investigations using a bimetallic catalyst with support originating from the fine fractions of other carbon particles (OCPf) and containing 13 wt% Mo and 2.5 wt% Ni resulted in an HDS and HDN conversion of 78 and 25%, respectively. Variation of metal compositions in catalyst formulation and its impact on hydrotreating activity was therefore considered in this study to enhance the hydrotreating activity of OCPf–supported catalyst, and to determine if the best NiMo/OCPf catalyst achieved from this study could be a viable catalyst for hydrotreating applications. The co-incipient wetness impregnation was used in preparing series of hydrotreating catalysts with Ni and Mo loadings within the range of (2.5–5.0 wt%) and (13–26 wt%) respectively. Overall, the catalyst samples with maximum Ni loading of 5.0 wt% and Mo loadings of either 13 or 19 wt% showed higher dispersion and the ability to form a Type II Ni-Mo-S phase with enhanced activity. The effects of metal compositions on both HDS and HDN activities were correlated with their physicochemical properties.

Oxidation Roasting of Fine-Grained Carbonaceous Gold Ore: The Effect of Aeration Rate

The oxidation roasting of carbon-bearing micro-fine gold can eliminate or weaken the robbing effect of carbonaceous materials and clay, and destroy the encapsulation of micro-fine gold. The micropores produced by gas escaping during the roasting process are conducive to the diffusion of leaching agents, thus enhancing the cyanide leaching of gold. In this paper, the influence of the aeration rate during roasting on the leaching rate of fine-grained carbonaceous gold ore and its mechanism were studied using thermodynamic calculations, crystal structure analysis, surface chemical groups and bonds analysis, microporous structure analysis, and surface morphology detection. Under suitable roasting conditions, the carbonaceous and pyrite in the ore are oxidized, while carbonate minerals such as dolomite and calcite as well as clay minerals are decomposed, and the gold-robbing materials lose their activity. The experimental results have theoretical and practical significance for the popularization and application of oxidation roasting technology of fine carbon-bearing gold ore.

Activated Carbons as Methanol Adsorbents for a New Cycle “Heat from Cold”

Activated carbons are widely used for sustainable technology of adsorptive transformation and storage of heat. Here, we analyze the applicability of twelve commercial carbons and an innovative carbonaceous composite “LiCl confined to multi-wall carbon nanotubes” (LiCl/MWCNT) for a new cycle “Heat from Cold” (HeCol). It has recently been proposed for amplification of low- temperature ambient heat in cold countries. The analysis is made in terms of the methanol mass exchanged and the useful heat generated per cycle; the latter is the main performance indicator of HeCol cycles. The maximum specific useful heat, reaching 990 and 1750 J/g, can be obtained by using carbon Maxsorb III and the composite, respectively. For these materials, methanol adsorption dynamics under typical HeCol conditions are experimentally studied by the large pressure jump method. Before making this analysis, the fine carbon powder is consolidated by either using a binder or just pressing to obtain larger particles (ca. 2 mm). The methanol desorption from the consolidated samples of Maxsorb III at T = 2 °C is faster than for LiCl/MWCNT, and the maximum (initial) useful power reaches (2.5–4.0) kW/kg sorbent. It is very promising for designing compact HeCol units utilizing the carbon Maxsorb III.

Processing nanoporous organic polymers in liquid amines

Rigid network structures of nanoporous organic polymers provide high porosity, which is beneficial for applications such as gas sorption, gas separation, heterogeneous (photo)catalysis, sensing, and (opto)electronics. However, the network structures are practically insoluble. Thus, the processing of nanoporous polymers into nanoparticles or films remains challenging. Herein, we report that nanoporous polymers made via a Knoevenagel-like condensation can be easily processed into nanoparticles (115.7 ± 40.8 nm) or a flawless film by using liquid amines as a solvent at elevated temperatures. FTIR spectra revealed that the carboxyl groups in the nanoporous polymers act as reactive sites for amines, forming new functionalities and spacing the polymeric chains to be dissolved in the liquid amines. The processed film was found to be CO2-philic despite the low surface area, and further able to be transformed into a fine carbon film by thermal treatment.

Fracture Toughness of CF-Plug Joints of Ti and Epoxy Matrix CFRP

A new method of linear connected joints (Ti/CF-plug/Epoxy) of Ti (Titanium) to Epoxy connected by CF-plug was innovated and developed, since fine carbon fibers (CFs) generate the extremely large friction force by their broad interface between metals and Epoxy polymer (M/Epoxy). Compared with glue and spontaneous adhesions of M/Glue/Epoxy and M/Epoxy, the new method remarkably improved the fracture toughness with maintaining light weight. To maintain the high joint strength of the Ti/CFW-CFJ/Epoxy, the Ni coating film on CF should control to bite the CF by molten Ti. The tensile strength (σb) and its strain (εb) of Ti/NiCFW-CFJ/Epoxy were higher than those of Ti/CFW-CFJ/Epoxy. In addition, increasing the CF-volume increases the σb. The CF-plug joint between Ti and Epoxy matrix CFRP apparently probably enhances the fuel efficiency, as well as safety level of airplane.

Development of an Electrostatic Precipitator with Porous Carbon Electrodes to Collect Carbon Particles

Exhaust gases from internal combustion engines contain fine carbon particles. If a biofuel is used as the engine fuel for low-carbon emission, the exhaust gas still contains numerous carbon particles. For example, the ceramic filters currently used in automobiles with diesel engines trap these carbon particles, which are then burned during the filter regeneration process, thus releasing additional CO2. Electrostatic precipitators are generally suitable to achieve low particle concentrations and large treatment quantities. However, low-resistivity particles, such as carbon particles, cause re-entrainment phenomena in electrostatic precipitators. In this study, we develop an electrostatic precipitator to collect fine carbon particles. Woodceramics were used for the grounded electrode in the precipitator to collect carbon particles on the carbon electrode. Woodceramics are eco-friendly materials, made from sawdust. The electrical resistivity and surface roughness of the woodceramics are varied by the firing temperature in the production process. Woodceramics electrodes feature higher resistivity and roughness as compared to stainless-steel electrodes. We evaluated the influence of woodceramics electrodes on the electric field formed by electrostatic precipitators and calculated the corresponding charge distribution. Furthermore, the particle-collection efficiency of the developed system was evaluated using an experimental apparatus.