Carbonization coke characterization

Disordered soft carbons. These carbons are characterized by disordered structure. They can be graphitized when heated to temperatures >2000°C. Typical examples are the petroleum cokes [338-340], which may insert lithium reversibly at a capacity lower than that of graphite. Hence, the intercalation stoichiometry is LixC6 (x < 1). 

When the carbonization process is divided into its distinct physical and chemical parts and both are considered according to their contributions to the overall process, only then is a description of the mechanism possible. Carbon precursors and the products of their carbonization are characterized by various test methods whose objectives can be the control of coking, a description of the carbon or the determination of its suitability for further application. This paper considers the significance of selected common characterization procedures. 

The coke materials discussed so far are made from coal. They are sometimes also called active carbon , if they are employed for purification processes. Capacities as high as 300 Ah/kg are reported in the literature [189]. Some papers are of special interest, for a broad spectrum of graphites and carbons were evaluated in the same laboratory [190,191]. Figure 21 shows that lithium-carbons are characterized by discharge curves with potentials which comprise a broader potential region of 0.1-1V vs. Li. The lithium-graphite potential is held at 0.1-0.3 V vs. Li, as mentioned above. 

The aim of our study was a characteiizatioii of the surface morphology (structure) and transformation of the carbon coke on the pure and NaP-modified MnOx-catalysts. An AFM was used to monitor the progress of the carbonaceous deposit formation (coking) over the catalyst surface, from the early stages up to the later stages when the surface is completely covered by carbon coke. XPS and FTIR were employed to characterize the chemical composition of the carbonaceous deposit on the MnOx surface. 

As some parts, at least, of the carbonization product have passed through a liquid or liquid-crystalline state, the resulting non-graphitic carbon is of the graphitizable variety. From a structural viewpoint, the term coke characterizes the state o/graphitizable carbon before the beginning of graphitization. 

Acetylene was discovered m 1836 by Edmund Davy and characterized by the French chemist P E M Berthelot m 1862 It did not command much attention until its large scale preparation from calcium carbide m the last decade of the nineteenth century stim ulated interest m industrial applications In the first stage of that synthesis limestone and coke a material rich m elemental carbon obtained from coal are heated m an electric furnace to form calcium carbide... 

Coumarone—indene or coal-tar resins, as the name denotes, are by-products of the coal carbonization process (coking). Although named after two particular components of these resins, coumarone (1) and indene (2), these resins are actually produced by the cationic polymerization of predominantly aromatic feedstreams. These feedstreams are typically composed of compounds such as indene, styrene, and their alkylated analogues. In actuaUty, there is very tittle coumarone in this type of feedstock. The fractions used for resin synthesis typically boil in the range of 150—250°C and are characterized by gas chromatography. 

Coke a gray to black solid carbonaceous material produced from petroleum during thermal processing characterized by having a high carbon content (95%+ by weight), a honeycomb appearance, and is insoluble in organic solvents. 

Under the optical microscope the texture of products derived from the three coals studied show an anisotropy of the type which already has been described for similar materials (I, 4, 9). The texture of the l.t. pitch coke is entirely isotropic, whereas the h.t. pitch coke is characterized by a pronounced anisotropy in bands. The anisotropy of the carbonization products of mixtures of l.t. and h.t. pitches varies linearly as a function of the composition of the mixture (8). 

As described in Section 3.3.3.1, the PFA-P7-H carbon better inherits the structural regularity from the parent zeolite than the other carbons. Moreover, the pore structure of this carbon is unique and it has never been found in any type of carbon. Its detail will be explained in this section in comparison with three commercial activated carbons MSC-30 (Kansai Coke and Chemicals), M-30 (Osaka Gas), and ACF-20 (Osaka Gas). The former two carbons were prepared from petroleum coke and mesocarbon microbeads, respectively, and both were activated with KOH. The last sample was activated with carbon fibers (ACFs). All are characterized by a large BET SSA. 

The H/C ratio of the coke deposits was quantified by temperature programmed oxidation (TPO) in a 1 % oxygen helium mixture. Temperature was raised to 850° C at a heating rate of 10° min 1. The calculations of the H/C ratio involved the results from the measurements of carbon dioxide production and oxygen uptake (according to Ref. [8]). Coke deposits were also characterized by thermogravimetry and transmission electron microscopy. 

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