Coal 9/14 blends, analyses

Fuel analysis results presented in Table 1 provide a comparison between the biofuels and coal. On an as-fired basis, the four bio els had significantly lower calorific values (8- 3 MJ/kg) compared to coal (21 MJ/kg), partly attributable to the higher moisture content of the biofuels. Also, biofuels had lower ash and fixed carbon contents but relatively higher volatile matter contents than both coal and bark/coal blend. 

The clear knowledge about the purity of a coal is decisive for the correct design of gasification processes. No other method than the petrographic analysis, especially the reflectance analysis, gives a more precise statement regarding composition of a coal sample. Other bulk parameters, such as fraction of volatile matter, carbon content, or heating values, are inappropriate to determine whether a pure coal or a mixture (coal blend) are on hand. 

Elemental analysis was performed on various coals, pitches, and blends. Table 7 reports the elemental composition of products from WVGS 13407. Compared to the raw coal, the NMP-soluble extract (EXT) contams essentially the same amount of carbon, though there is slightly more hydrogen as mdicated by a... 

The melt used in this work was prepared from the residue of hydrogen-donor extraction of Colstrip coal with tetralin solvent in such a way as to simulate the composition of an actual spent melt. The extraction was conducted in the continuous bench-scale unit previously described (17) at 412°C and 50 min residence time. The residue used was the solvent-free underflow from continuous settling (17) of the extractor effluent. The residue was then precarbonized to 675°C in a muffle furnace. The melts were blended to simulate the composition of a spent melt from the direct hydrocracking of the Colstrip coal by blending together in a melt pot zinc chloride, zinc sulfide, and ammonium chloride, ammonia, and the carbonized residue in appropriate proportions. Analysis of the feed melt used in this work is given in Table I. 

As well as inorganic complexes, thermal analysis is applicable to a wide range of substances, e.g. polymers, drugs, soils and coals. It can also be applied to mixtures of, for example, polymer blends. 

A significant reduction in cost could be achieved if appreciable quantities of coal-tar pitch could be incorporated into ABS for the production of a satisfactory pipe compound. Because of the availability of trained plastics and mathematics personnel at the U. S. Steel Research Laboratory, an interdisciplinary approach was made to the problem. Before any blending was done, an appropriate experiment was designed to obtain a maximum output of information with a minimum amount of experimentation. This paper reports the results and analysis of the experimentation. 

Coal petrography (Chapter 4) has become widely used for predicting coke quality based on coal analysis and has led to a system for predicting coke stability based on petrographic entities and reflectance of coal (Schapiro and Ciray, 1960). Thus, an optimum blend of coals could be selected to produce desired coke quality. 

Where NOx is measured in kg/GJ, FR is firing rate in GJ/hr, EO2 is excess O2 expressed as a percentage (total basis), FN is fuel nitrogen expressed in kg/GJ, and V/FC is the volatile/fixed carbon ratio from the proximate analysis of the blend of coal and woody biomass. Alternatively ... 

A mixture of several coals—a so-called blend—can only be clearly identified from a maceral analysis. 

As shown in the previous section, a petrographic analysis should not be limited to fresh coal only for rank and blend determination. Also specific samples from unstable gasifier operation, depositions, and solid by-products can reveal significant information understanding the process and resolving potential problems. 

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