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We have considered the measurement results of the thermogravimetric (TG) and Brunauer Emmett Teller (BET) analysis of the carbon products from the DC arc of high current [1, 2] and the raw original graphite material. The TGA measurements was taken in nitrog en atmosphere at TGA21000 and the weight variation in percent on temperature was given in Fig 1. The similar study for carbon materials can be found in Ref. [3, 4]. The measurement results were processed on Mathematica software. The measurement data is of course a noisy and includes many of the same values at one values of temperature. In first step of data processing, the same values were changed to their mean values and at next step, the noisy data is filtered to the smooth data. The raw and smooth (filte red) data were depicted in Fig. 1 as the residue mass percentage versus temperature. Although the weight gain in plot is, in general, related to the chemical reactions leading to formation of compounds and the adsorption of gases on samples, the observed g ain in the beginning of the plot is mainly caused by the buoyancy effect in which the density of surrounding gas decreases and does the lifting force. However, the gradual gain observed in the end part of the plot for the graphite is caused by newly arisen pores with high temperature and the adsorption of surrounding nitrogen on it because the samples’ porosity the increases at high value of temperatures which result is given by the BET analysis. This gain was not observed for the product and it means the p roduct became already porous material. The plots tell us that the samples have multistep decomposition upon heating. This says that the samples might have three different phases of decomposition. The comparing the medium step of decomposition for two sampl es shows that the decomposition temperature range clearly shifted each other and broaden for the product. The tendency TGA curves for two samples resembles but, the rates are different.
In this study, we aimed to estimate the weight fraction of crystalline phases in a cathode deposition formed by DC arc-discharge between graphite electrodes in water via the XRD method and CARBON XS program based on Shi model, which takes into account disorder and stacking faults in a graphite structure. The structural computation of graphitic carbon materials for comparison was done by using CARBON XS according to Shi model. From the study, we observed that the total weight fraction of 2H hexagonal and 3R rhombohedral ordered structures of graphitic carbon decreases from 77.69% to 48.98%, whereas the weight fraction of random shift and stacking faults increases from 22.31% to 51.02% as compared to these parameters belonging to pure graphite structure during the arc-discharge process.
Products from combustion in arc discharge region such as soot and ash have been analyzed by using various techniques and analyzing methods. The some physical properties of particulates of soot and ash from coal combustion are determined. (i) The elemental analysis on particulate surface was done for soot and ash and elements in them were determined. Noncombustible elements are dominated in spectrum of ash, however they encounter rarely in soot. (ii) The results from the morphological analysis on particulates of soot by using SEM and BET show that they tend to have large free surface and pore volume. The size of pore in soot and ash particulates decreases with their diameter. The ash particulates are infe rred as poor porous material from result of study. The circularity and roundness of soot is higher than ash particulates.
