32 research outputs found
Alcohol Synthesis over Pre-Reduced Activated Carbon-Supported Molybdenum-Based Catalysts
Activated carbon (AC)-supported molybdenum catalysts, either with or without a potassium promoter, were prepared by the incipient wetness impregnation method. The materials were characterized using differential thermal analysis (DTA) and temperature programmed reduction (TPR), and were used for mixed alcohol synthesis from syngas (CO+H2). DTA results showed that a new phase, related to the interaction between Mo species and the AC support, is formed during the calcination of the Mo/AC catalyst, and the introduction of a K promoter has noticeable effect on the interaction. TPR results indicated that the Mo is more difficult to reduce after being placed onto the AC support, and the addition of a K promoter greatly promotes the formation of Mo species reducible at relatively low temperatures, while it retards the generation of Mo species that are reducible only at higher temperatures. These differences in the reduction behavior of the catalysts are atributed to the interaction between the active components (Mo and K) and the support. Potassium-doping significantly promotes the formation of alcohols at the expense of CO conversion, especially to hydrocarbons. It is postulated that Mo species with intermediate valence values (averaged around +3.5) are more likely to be the active phase(s) for alcohol synthesis from CO hydrogenation, while those with lower Mo valences are probably responsible for the production of hydrocarbons
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Development of Continuous Solvent Extraction Processes For Coal Derived Carbon Products
In this reporting period, tonnage quantities of coal extract were produced but solid separation was not accomplished in a timely manner. It became clear that the originally selected filtration process would not be effective enough for a serious commercial process. Accordingly, centrifugation was investigated as a superior means for removing solids from the extract. Results show acceptable performance. Petrographic analysis of filtered solids was carried out by R and D Carbon Petrography under the auspices of Koppers and consultant Ken Krupinski. The general conclusion is that the material appears to be amenable to centrifugation. Filtered solids shows a substantial pitch component as well as some mesophase, resulting in increased viscosity. This is likely a contributing reason for the difficulty in filtering the material. Cost estimates were made for the hydotreatment and digestion reactors that would be needed for a 20,000 ton per year demonstration plants, with the aid of ChemTech Inc. The estimates show that the costs of scaling up the existing tank reactors are acceptable. However, a strong recommendation was made to consider pipe reactors, which are thought to be more cost effective and potentially higher performance in large scale systems. The alternate feedstocks for coke and carbon products were used to fabricate carbon electrodes as described in the last quarterly report. Gregory Hackett successfully defended his MS Thesis on the use of these electrodes in Direct Carbon Fuel Cell (DCFC), which is excerpted in Section 2.4 of this quarterly report
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DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale