Charcoal, preparation

On the whole it is better to employ the activated decolourising charcoal prepared from wood. Excellent decolourising carbons are marketed under the trade names Norit (from birch wood), Darco and Nuchar. ... 

Charcoal—sulfur processes need low ash hardwood charcoal, prepared at 400—500°C under controlled conditions. At the carbon disulfide plant site, the charcoal is calcined before use to expel water and residual hydrogen and oxygen compounds. This precalcination step minimises the undesirable formation of hydrogen sulfide and carbonyl sulfide. Although wood charcoal is preferred, other sources of carbon can be used including coal (30,31), lignite chars (32,33), and coke (34). Sulfur specifications are also important low ash content is necessary to minimise fouling of the process equipment. 

Avoid foods that contain xanthine, such as colas, coffee, chocolate and charcoal-prepared foods. 

The most widely used form of the carbonaceous fuels is perhaps the solid fuel, coal. Though occurring basically in the solid form, coal can be converted to both liquid and gaseous forms. In the solid form, coal is basically of two types charcoal (prepared by carbonization of wood) and mineral coal (obtained from coal mines). Coal is found on every continent,... 

Treatment — Oral superactivated charcoal preparation is standard therapy for poison ingestion. This type of preparation is five times stronger than ordinary charcoal. Supportive therapy must be provided, depending on the symptoms displayed. No antitoxin is currently available for human use. However, an experimental antitoxin has shown some promise in animals.3... 

Preparation of Tin by Reduction with Charcoal. Prepare a mixture of 2.5 g tin(IV) oxide, 1 g of charcoal, and 0.5 g of ammonium carbonate. Transfer the mixture into a crucible and roast it in a muffle furnace. Write the equation of the reaction. Transfer the obtained bead into another crucible and fuse it with borax. After cooling, break the crucible and wash off the borax with hot water. 

The following analyses of two samples of charcoal prepared by the meiler syBtem, show tho quantity of tho different ingredients remaining, even after the charring has been carried to ite utmost limits.—... 

Looking at the other end of the respiratory chain, Otto WarburgC/d noted in 1908 that all aerobic cells contain iron. Moreover, iron-containing charcoal prepared from blood catalyzed nonenzymatic oxidation of many substances, but iron-free charcoal prepared from cane sugar did not. Cyanide was found to inhibit tissue respiration at low concentrations similar to those needed to inhibit nonenzymatic catalysis by iron salts. On the basis of these investigations, Warburg proposed in 1925 that aerobic cells contain an iron-based Atmungsferment (respiration enzyme), which was later called cytochrome oxidase. It was inhibited by carbon monoxide. 

C ( amorphous/ charcoal). Thiele1 studied the heat of combustion of charcoal prepared from sugar as a function of the temperature of preparation, and found that the heat of combustion was constant only for samples prepared above 1400°. The data of Thiele,1 Mixter,3 and Favre and Silbermann,1-5-11 yield, respectively, 96.4, 96.6, and 96.4 for the heat of the reaction, C ( amorphous, charcoal) +02 (g) =CC>2 (g). Data on the heat of combustion of this form of carbon were also reported by-Peterson,111 Despretz,1 Berthelot and Petit,2 Dulong,2 Andrews,14 16 Berthelot and Vielle,7 12 Ruff and Gersten,2 Thomsen,7 16 Pfaundler,3 Niki-ten,1 and Lavoisier and Laplace1 (see Mellor1). 

The capture of HCl gas just before the thermal crackiug is another characteristic of this process. The two tanks are alternatively used to protect the catalyst from HCl attack. Activated charcoal prepared from pahn shell is applied at a loading of 13% K2CO3. 

Charcoal historically has been an important adsorbent for a wide range of solutes. Surface areas are often in the range of 1500 m /g. Graphitized charcoal prepared at high temperature is relatively nonpolar, whereas oxidized charcoal prepared by low-temperature oxidation is relatively polar. 

Effervescent products of water-insoluble drugs have been manufactured. A successful example is the effervescent activated charcoal preparation suggested in the management of theophylline poisoning. ... 

Boyd R, Hanson J. Prospective single blinded randomised controlled trial of two orally administered activated charcoal preparations. J Accid Emerg Med 1999 16(l) 24-5. 

Ftg. 2. Cross-section (a) and longitudinal section (b) of grey alder charcoal prepared... 

EORA tar is a promising catalyst to prepare charcoal for activated carbon production. The charcoal obtained in runs using the EORA tar cdtaly si was activated in half the time necessary to activate the charcoal prepared w ithout the use of the catalyst. The adsorption efficiency of activated carbon was 1.3 to I 6 times higher if the charcoal was produced in a catalysed process, and Che pore size of the adsorbent was also uniform The charcoal prepared in an EORA tar catalysed process contained 0 3 to 0.5% of sulphur. Tlie activated carbon did not contain sulphur. 

Cellulose, preparation Centrifugation Charcoal, preparation purification Chelex... 

Proton resonance of charcoals prepared by heat treatment of dextrose at various temperatures was studied before and after hydrogen treatment by Turkevich, Mackey and Thomas.(136) This was followed by a preliminary study of double (electron-proton) resonance by Turkevich and Derouane(153) of benzene adsorbed on charcoal. This investigation was completed recently by M. Che and J. L. Vendrine.(154)... 

When the adsorption of same fatty acids from aqueous solutions was studied on a charcoal prepared under strongly oxidizing conditions (Figure 3.29), Traube s rule shows a reversal, which means that the magnitude of adsorption decreases as we ascend the homologous series. This has been attributed to the polar nature of the charcoal surface, due to the presence of polar carbon-oxygen surface groups, which... 

Molecular sieve carbons contain ultraflne micropores that permit the penetration of smaller molecules but impede the entry of larger molecules. The diffusion of certain gases and vapors into these materials is an activated process and is strongly temperature dependent. Thus, Marsh and Wyne-Jones observed that the uptake of nitrogen at 77 K for a polymer carbon was much smaller than its uptake of CO2 at 195 K. Kipling et al. observed that the surface area of a polymer charcoal prepared by carbonization at 700°C was very low when measured by adsorption of nitrogen at 77 K than when measured by the adsorption of CO2 at 195 K. 

FIGURE 4.11 Pore size distribution of charcoals prepared from balsa, grant ipil-ipil, and bamboo, (a) Pore size distribution of raw wood and charcoal carbonized at 700°C for 1 h at a heating rate of 50°C/min and (b) dependence of pore volume on heat treatment temperature and rate. 

The pore volume, and consequently the sorption capacity of charcoals, depend strongly on carbonization conditions. Charcoals prepared from balsa exhibited a relatively high sorption capacity of 30 kg/kg. 

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