Coal, analyses powdered

The chlorination of a powdered coal analysis C, 61.5 H, 1.4 N, 1.3 Cl, 2.9% with liquid dichlorine at 490 C and 40 atmospheres pressure in a Carius tube (16 h) in the absence of air was found to produce phosgene in a yield (carbon-based) of about 6%. CCl., and large amounts of HCl were also formed [ICI103]. The formation of phosgene was also noted during the gaseous chlorination (in the absence of air) of petroleum cokes in the temperature ranges of 500-850 C [1786] and of 800-1000 "C [717]. A maximum yield of... 

Lithium insertion in microporous hard carbons (region 3 in Fig. 2) is described in section 6. High capacity hard carbons can be made from many precursors, such as coal, wood, sugar, and different types of resins. Hard carbons made from resole and novolac resins at temperatures near 1000°C have a reversible capacity of about 550 mAh/g, show little hyteresis and have a large low voltage plateau on both discharge and charge. The analysis of powder X-ray diffraction. 

Because SEM-AIA is often used to explain behavior under specific processing conditions, samples are prepared in the same size in which they are received. Coal samples with their included mineral matter are prepared for image analysis by mixing samples. of the dry coal with polyethylene powder (as a diluent) and molten carnauba wax in a volume ratio of 1 2 2. Pellets are then cut along the cylindrical axis to expose a vertical cross section of coal and mineral matter and polished using standard petrographic procedures. The surfaces are coated with 150 A of carbon to provide a conductive surface for SEM examination. 

Choice of an Internal Standard. One of the difficulties in the spec-trometric trace analysis of coal ash samples, in addition to choosing a suitable comparison standard matrix, is choosing an internal standard. The first choice in both analytical methods was indium, which was used as a constant internal standard added to the graphite powder diluent-buffer. The results obtained had poor reproducibility, as previously... 

ASTM method D3175 (H), and forms of sulfur by ASTM method D2492 (21). Elemental analysis of the ash was performed using ASTM method D3682 (22). Carbon aromaticity was determined using 13c NMR CP-MAS procedures described elsewhere (13). X-ray powder diffraction analysis of the mineral matter in the whole coal was performed using a Rigaku powder dif-... 

Germanium was determined in coal dust after conversion into the chloride [604] by treatment with hydrogen chloride at a high temperature on a mixture of coal powder and Chromosorb (1 1), wetted with sulphuric acid. The analysis of a sample of 1.5 g was reported having a sensitivity of 3.3 ppm of germanium with an error of 6%. 

Paulownia charcoal. A light powder, which is easily scattered and has an apparent specific gravity of 0.12 g/cc. This value is the lowest for all the kinds of charcoal at present available. The dye adsorption power in water lies between pine charcoal, and hemp coal which has the largest. One analysis showed that it contained. 9% moisture and 2.5% ash. The pH value of the wash water(5 grams of charcoal / 30cc of water) was 7 5 A mixture of the paulownia charcoal, sulphur and potassium nitrate burns as well as the pine charcoal, but it produces less fire dust than the pine charcoal. 

TJ apid entrainment carbonization of powdered coal under pressure in a partial hydrogen atmosphere was investigated as a means of producing low sulfur char for use as a power plant fuel. Specific objectives of the research were to determine if an acceptable product could be made and to establish the relationship between yields and chemical properties of the char, with special emphasis on type and amount of sulfur compound in the product. The experiments were conducted with a 4-inch diameter by 18-inch high carbonizer according to a composite factorial design (1, 2). Results of the experiments are expressed by empirical mathematical models and are illustrated by the application of response surface analysis. 

The coke residue is the result of the hydrogen-deficient stoichiometry of the process. With a proximate analysis (determination of the compounds, moisture, ash, etc., present) of carbon 80%, volatiles 10%, sulfur 6%, and ash 4%, the coke has a fuel value near that of high rank coals. It is burned in the site power plants to provide steam and electrical power for oil sands processing. However, the high sulfur content detracts from its wider utility as a fuel. Any coke in excess of the current fuel requirement is finely powdered and incorporated into the dyke walls to help trap any hydrocarbons present in water seepage through the wall. 

Figure 4. Analysis of water extracts from coal. Pvunp Micro Feeder. Column SC-01, 50 cm X 0.22 mm i.d. Mobile phase acetonitrile-water, gradient profile as Indicated. Flow-rate 1.04 yl/min. Sample 2.5 ml of distilled water in contact with powdered coal. Precoliatm Develosil ODS-15/30, 10 X 0.2 mm i.d. Wavelength of UV detection 225 nm. Reproduced with the permission from Ref.7 Copyright 1983, Huethig.

Although one must be aware of the potential problems posed by particle size effects in slurry and powder analysis, in many cases, the range of particle size and particle composition for a process stream is sufficiently constant that reliable measurements can be made using on-line XRF systems. Successful applications which have been reported include an on-stream XRF measuring system for ore slurry analysis [38] a system for direct XRF analysis of pulverised coal streams [39] and on-stream analysis of cement using XRF [2, 40]. The latter is available as a commercial on-stream cement analyser which it is claimed can measure lime saturation factors (a function of Ca, Si, A1 and Fe concentrations) with a relative standard deviation of better than 1% in 100 s measurement time. Obtaining such results with a sampHng frequency of over 10 measurements per hour can allow effi-... 

The use of NIR reflectance has gained considerable interest for process analysis in the food, pharmaceutical, petrochemical, and other chemical industries. This method requires little or no sample preparation and involves measurement of the reflectance of a liquid or solid sample relative to that of a standard in the same wavelength series. As illustrated in Table 3, process NIR has gained considerable use for moisture determination in coal, cosmetics, and detergent powders, as well as for protein contents of cereal and grain, and hydrogenation of unsaturated fats and oils. 

Examples of the AAS analysis of powdered samples, as well as such solid foods as chocolate and flour, are presented in [ 137]. [ 138J. The direct determination of mercury in soils, coal, and ash is di.scussed in [139]. ICP—OES (and ICP—MS) can also be transformed into a direct process through solid sample introduction and electrothermal pretreatment [140J. 

Since the initial introduction of laser diffraction instrumentation in the 1970s, many different applications to particle size analysis have been reported. These have included measurements of size distributions of radioactive tracer particles, ink particles used in photocopy machines, ziiconia fibers, alumina particles, droplets from electronic fuel injectors, crystal growth particles, coal powders, cosmetics, soils, resins, pharmaceuticals, metal catalysts, electronic materials, photographic emulsions, organic pigments, and ceramics. About a dozen instrument companies now produce LALLS instruments. Some LALLS instruments have become popular as detectors for size-exclusion chromatography. 

Milling of coal or coke produces a powder called pulverized fuel which contains particles of a wide range of sizes. As we saw in Chapter 3, the distance at which a particle in a particle-laden jet will travel in a combustion chamber plays a role in the damping of the jet s turbulent energy. Therefore theoretical analysis of combustion must take the particle size distribution of the fuel into account. Pulverized fuel fineness is therefore an important parameter in the modeling of coal combustion. An analytical expression of particle size distribution that has found a wide application for expressing the fineness of pulverized fuel is the Rosin-Rammler relation. The relationship is given by (Field et al., 1964)... 

Reactivity of petroleum coke, like all solid fuels, is a function of chemical structure. Recognizing that the vast majority of all petroleum coke is produced in delayed cokers, analysis focuses upon delayed petroleum coke. Reactivity measures used here include maximum volatile yield and both devolatilization and char oxidation kinetics. Black Thunder Powder River Basin (PRB) subbituminous coal and Pittsburgh 8 bituminous coal are shown, for comparison, as reference fuels. 

The example shown in Figure 13.29 is the spectrum of a high-volatUity coal. The sample was prepared by grinding as described under the discussion of mulling at a concentration of about 10% with KBr powder. Coal is a difficult sample to prepare for an IR spectrum, and diffuse reflectance provides a relatively easier way to produce good data. Quantitative analysis has been performed on coal samples using this technique (see Fredericks et al.). 

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