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The copper-catalysed reduction of NO with CO has been investigated over copper-loaded carbon materials (graphites and activated carbon). The NO + CO reaction has been studied in the presence and in the absence of oxygen. The carbon-supported copper catalysts have a very high activity for the reduction of NO with CO; however, the presence of oxygen inhibits the reaction. Variations in catalytic activity...
Boron oxide (B 2 O 3 ) has been impregnated into a high-density isotropic graphite block and a felt carbon fiber reinforced carbon composite (C-C composite). Impregnation was carried out at 1200°C under a pressure of 15 MPa for 1 hour. The bulk density of the original graphite and C-C composite increased by 12% and 20% respectively as a result of impregnation. The mechanical properties...
Previous studies have shown that lamellae of mesophase pitch prefer to be oriented parallel to a magnetic field. In the present work the matrix mesophase layers of the C/C composites were oriented perpendicular to the carbon fibers by a 8000 G magnetic field. This study is concerned with the internal friction of unidirectional C/C composites produced by the method of the present research. It is...
A modification of the porous texture of activated carbons to develop meso-a nd macroporosity is described. Three gas-activated carbons of different origin, have been modified by impregnation with two carbon compounds (d-glucose and d-glucosamine) from aqueous solution followed by carbonization at 1173 K and activation with CO 2 . The most important results of this procedure are (1) the development...
Four coal-tar pitches were used in conjunction with a woven carbon fibre cloth to produce carbon/carbon preforms and, after densification by impregnation/carbonisation using the same pitch, densified composites. Analysis of microscope images from polished sections was used to allow study of the effect of the nature of the matrix-precursor pitch on the void structure in the two materials. Voids were...
Activated carbons impregnated with a mixture of copper(ii), iron(ii), iron(iii) and chromium(iii) oxide catalysts were prepared in order to facilitate catalytic regeneration of AC saturated with phenols. The temperature ranges of phenol oxidation (T p ), carbon oxidation (T c ) and carbon burn-off were determined from DTA/TGA investigations in oxidizing and inert atmospheres. The...
The increasing importance of carbon materials in catalytic processes is analyzed in terms of the most important characteristics of these materials when acting as catalysts or catalyst supports. Thus, surface area, porosity, chemical inertness and oxygen surface groups affect not only the preparation, but also influence the resistance to sintering and the catalytic activity and selectivity of the...
Four unidirectional pitch-based C/C composites were densified by multiple melted pitch impregnation under vacuum followed by recarbonization to 1273 K. The pitches used for the impregnation were the same pitches used as carbon matrix precursors in the preparation of the C/C composites. Recarbonization steps in one of the composites were also performed under pressure in order to study the effect of...
Activated carbons can be impregnated with metal oxides (Cr, Cu, Ag, Mo, Zn, Cc) and/or organic compounds (triethylenediamine (TEDA)) to help capture high vapor pressure substances. However, this process lowers the temperatures of initial oxidation and spontaneous ignition and affects both the CO and CO 2 effluent concentrations upon heating. This study quantifies the depression of the point...
Properties of activated carbons at elevated temperature, specifically the spontaneous ignition temperature (SIT) and the point of initial oxidation (PIO), are of great significance in a number of unit operations. Although the SIT and PIO should be evaluated for each individual use, a standard method is required to compare products, insure quality, and optimize processes. Different methods for determining...
A new heterogeneous copper catalyst was developed using highly porous activated carbon as the catalyst support. The catalyst was designed to promote the oxidation of organic pollutants in dyeing and printing wastewater from the textile industry, which was carried out in a 2 l high-pressure reactor. The new catalyst enhanced the conversion of organic compounds in dyeing and printing wastewater, shortened...
The adsorption isotherms of fluoride from an aqueous solution on plain and aluminum-impregnated activated carbons were measured in this study. The impregnated carbon was prepared by impregnation with an aluminum nitrate solution at a fixed pH, followed by calcination under nitrogen at temperatures above 300°C. The adsorption of fluoride on impregnated carbon was shown to be dependent upon both the...
Puffing inhibition of coal tar based needle coke was effectively achieved regardless of the repeated impregnating and heating rate at the graphitization by impregnation with disodium hydrogen phosphate (DHP) and boric acid into the needle coke. Inhibitors were found dispersed into pores of the coke by impregnating and heat-treating the inhibitors on the coke. Such inhibitors in the pore prohibited...
A new carbon fiber reinforced glued laminated timber (CFR-glulam) with high performance and fire endurance properties, which originated through the development of a new phenolic resin and intermediate material which is CF composite sheet (CF/P) and production system, is reviewed. The intermediate material, CF/P sheet, newly developed, was composed of a CF reinforced composite sheet sandwiched by resin...
Adsorption of model organic compounds from solutions in n-heptane, acetonitrile and an acetonitrile-water mixture (40/60 v/v) on the surface of new types of mesoporous carbon sorbents has been studied applying liquid chromatographic and static adsorption measurements. The values of specific retention volumes, absolute retention volumes, capacity factors and Henry constants of organic compounds on...
Interactions between methanol and the carbon-supported catalysts have been investigated by in situ infrared spectroscopy. The pure, nonoxidized carbon itself is unreactive in decomposition of methanol. FTIR spectra showed that methanol adsorbed molecularly on oxidized carbon surface dissociated upon heating. Methoxy species generated by dissociative methanol adsorbed on oxidized carbon surface decompose...
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