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Precursors, of activated carbon

Olivares-Marm, M., J. A. Fernandez, M. J. Lizaro et al. 2009. Cherry stones as precursor of activated carbons for supercapacitors. Materials Chemistry and Physics 114 323-327. [Pg.216]

More recent studies were carried out with coals (lignite and subbituminous), enriched with nitrogen, before carbonization and activation, by treatment with ammonia and its derivatives, mainly urea [36,37]. The ammoxidation reaction (reaction with an ammonia-air mixture) is another route to obtaining nitrogen-enriched precursors of active carbons from various carbonaceous materials, such as pine wood, peat, lignite, subbituminous coal [38], and cellulose [39]. [Pg.136]

As a result of their outstanding physical and mechanical properties, aromatic polyamides are attractive materials for use in high-performance structural applications 853072 833611 820253, including aircraft components or fire protection garments, as constituents of both traditional, i.e., fibre-reinforced composites 774110 762844, and molecular composites. One of these applications takes advantage of their thermal stability 881232 825031 763791 755849 and allows the manufacturing of heat-resistant materials for fire protection 713906. In a different context, aromatic polyamides (aramid fibres) have been proposed in the past few years as precursors of activated carbon materials with distinctive adsorbent properties (thermally stable molecular sieves). Aramid fibres, e.g., poly(w-phenylene isophthalamide), poly(p-phenylene terephthalamide) 709654, etc., are a class of synthetic polymers that possess excellent thermal and oxidative stability, good flame resistance, and superior mechanical and dielectric behaviour. [Pg.189]

Azaigohar, R., Dalai, A. K. Biochar as a precursor of activated carbon. Appl Biochem Bio-technol 2006,129-132,762-773. [Pg.365]

The stmcture of activated carbon is best described as a twisted network of defective carbon layer planes, cross-linked by aHphatic bridging groups (6). X-ray diffraction patterns of activated carbon reveal that it is nongraphitic, remaining amorphous because the randomly cross-linked network inhibits reordering of the stmcture even when heated to 3000°C (7). This property of activated carbon contributes to its most unique feature, namely, the highly developed and accessible internal pore stmcture. The surface area, dimensions, and distribution of the pores depend on the precursor and on the conditions of carbonization and activation. Pore sizes are classified (8) by the International Union of Pure and AppHed Chemistry (lUPAC) as micropores (pore width <2 nm), mesopores (pore width 2—50 nm), and macropores (pore width >50 nm) (see Adsorption). [Pg.529]

The process for the thermal activation of other carbonaceous materials is modified according to the precursor. For example, the production of activated carbon from coconut shell does not require the stages involving briquetting, oxidation, and devolatilization. To obtain a high activity product, however, it is important that the coconut shell is charred slowly prior to activation of the char. In some processes, the precursor or product is acid-washed to obtain a final product with a low ash content (23,25). [Pg.530]

Lin, R. Y. and Economy, J., Preparation and properties of activated carbon fibers derived from phenolic resin precursor, Appl. Polym. Symp., 1973, 21, 143 152. [Pg.112]

In 1951, ferrocene was synthesized by Pauson [17] and Miller [18]. Soon after this synthesis, two groups led by Wilkinson and Fischer, independently reported that ferrocene has a stable carbon-iron 7r-bond [19]. This was the first example of a true organotransition metal complex containing a carbon-metal bond. Since then, numerous organotransition metal complexes have been prepared. The importance of these complexes as intermediates of many synthetic reactions has been discovered. More importantly, some transition metal complexes were found to behave as precursors of active catalysts. [Pg.5]

Two major strategies can be used for the recovery and purification of CPC. One strategy involves the use of activated carbon or the use of a nonionic resin. Because of the high selectivity of the resin, CPC is preferentially adsorbed over penicillin N or the contaminating biosynthetic precursor molecules. Most of the penicillin N is removed in the pH 2.0 acidification step. An additional anion- and cation-exchange step usually results in high-quality CPC. A large fraction of the CPC is converted to 7-ACA and derivatized to semisynthetic cephalosporins. [Pg.134]

Activated carbon is a finely divided form of amorphous carbon manufactured from the carbonization of an organic precursor, which possesses a microporous structure with a large internal surface area. The ability of the hydrophobic surface to adsorb small molecules accounts for the widespread applications of activated carbon as gas filters, decoloring agents in the sugar industry, water purification agents, and heterogeneous catalysts. [Pg.506]

FIGURE 2.18 Preparation process of activated carbon from thermosetting and thermoplastic precursors. [Pg.54]

Over a period of almost a century activated carbons have remained the most widely used of all the general-purpose industrial adsorbents. In 1995, the world annual production of activated carbons was estimated to be in the region of400 000 tonnes, with consumption increasing at about 7% per annum (Derbyshire et al., 1995). They are manufactured from a variety of precursors, but cheap and readily available materials such as wood, peat, coal and nut shells are still generally used for large-scale production (Baker, 1992). [Pg.239]

K [1,3], which would result in the drastic increase of the mesopore in the activated carbons synthesized in 100% Hj. Based on these mechanisms of the mesopore production, control of the particle size of the Fe compound should be important to produce mesopores. The size of the particles can be controllable through adjustment of the introduced amount of Fe in the precursor, dispersion of Fe at the preparation stage of the precursor and the condition of heat-treatment such as heating rate and treatment temperature. The conditions should be optimized depending on precursors. We also confirmed the effectiveness of the present method in selective increase of mesopores of activated carbons using used coffee beans and tea leaves wastes. The results will be presented in the next paper. [Pg.402]


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