Coal percentage, calculation

COAL 9 Calculate the percentage composition of any compound whose formula is given (or known). 

Fixed carbon, the residue left after the volatile matter is driven off, is calculated by subtrac ting from 100 the percentages of moisture, volatile matter, and ash of the proximate analysis. In addition to carbon, it may contain several tenths of a percent of hydrogen and oxygen, 0.4 to 1.0 percent nitrogen, and about half of the sulfur that was in the coal. 

Coal analyses are reported on severalbases, and it is customaiy to select the basis best suited to the application. The as-received basis represents the weight percentage of each constituent in the sample as received in the laboratoiy. The sample itself may be coal as fired, as mined, or as prepared for a particular use. The moisture-free (diy) basis is generally the most useful basis because performance calculations can be easily corrected for the ac tual moisture content at the point of use. The dry, ash-free basis is frequently used to approximate... 

The composition of a gas derived by the gasification of coal is, volume percentage carbon dioxide 4, carbon monoxide 16, hydrogen 50, methane 15, ethane 3, benzene 2, balance nitrogen. If the gas is burnt in a furnace with 20 per cent excess air, calculate ... 

The recovery percentages of coal and solvent (BI/ coal fed, BS/solvent fed, respectively) calculated based on the above assumption are summarized in Table 4. They were more than 85% except for the significantly low value for the coal recovery when hydropyrene was used as the solvent. In the latter case, some extent of the coal may be converted into the benzene soluble. Nevertheless, analyses of BS and BI fractions may inform the structural change of coal and solvent after the liquefaction. 

Calculate the percentage (w/w) of coal tar in the finished product when 8 grams of coal tar is mixed with 120 g of a 4% coal tar ointment. 

Radiochemical yields are within 46-74%. The average relative standard deviation of the method is 8%. The accuracy of the method was checked by analysis of a U. S. Geological Survey rock standard. Gallium concentrations in 101 coals, calculated from the concentration in the coal ash and the percentage of low-temperature ash in the coal, range from 1.1 to 7.5 ppm, the median value being between 2.9 and 3.0 ppm (16). 

Separating the three macerals from the dull coal was difficult. The petro-graphical purity of the exinite is 86% and that of the micrinite 94%. For both macerals, vitrinite is the main impurity. Since the vitrinite has a petrographi-cal purity of 99%, it is not difficult to calculate the values for the pure exinite and pure micrinite from the experimental data on the highly enriched maceral fractions. All values reported in the tables are corrected ones. Table I summarizes the results of elementary analysis (maf) and the percentage of volatile matter. 

Moisture values are very important, due to the influence they have on other measured and calculated values used in coal analysis and, ultimately, to the part they play in the buying and selling of coal. The moisture values obtained from the various drying procedures are expressed as a percentage, by weight, of the... 

Porosity is the fraction (or percentage) of the volume of coal that is occupied by pores and can be calculated from the equilibrium moisture content (Chapter 3)... 

Samples of South Blackwater and Ensham coal of +16.0 mm size were collected separately, from the stockpiles of the Gladstone Port. Before testing, both types of coals were sieved to obtain a —76.2 + 50.8 mm sized samples for the drop tests. The sample was placed inside the released hopper, which was raised by overhead crane. A sample of 10 kg was dropped each time onto an enclosed horizontal steel plate, conveyor belt and coal stockpile. The dropped coal was sieved to remove the fines (-16.0 mm size). In this way the percentage of fines produced at each drop were determined. The calculation methodology for fines percentage was given in Sahoo et al. [2],... 

A comparison of the experimental HHVs with the calculated HHVs for the biomass, coal, and peat using the carbon analyses listed in Table 3.5 is shown in Table 3.8. With the exception of the primary biosolids sample, the percentage error of the calculated HHV is relatively small. 

A similar catalyst was used in the study of Diez et aP, deactivated with either a light catalytic cycle oil or a coal residuum. As the reaction temperature was increased from 335°C to 395°C, the amount of coke increased from 1.5 wt% to 3 wt% and the aromaticity from 40% to 70%, as measured by CP MAS NMR. The aromaticity was calculated from the percentage of sp carbon signal. When using the coal residuum as feed, the aromaticity increased up to 73% and the coke content up to 10%, at 415°C. 

---