Book Synopsis Formulas for Calculating the Heating Value of Coal and Coal Char by :
Download or read book Formulas for Calculating the Heating Value of Coal and Coal Char written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new five-term formula for calculating the heating value of coal from its carbon, hydrogen, sulfur and ash content was obtained by regression analysis of data on 775 samples of US coals of all ranks. The standard deviation of the calculated value from the observed value was 129 Btu/lb, compared to apparent standard deviations ranging from 178 to 229 Btu/lb obtained from the Dulong, Boie, Grummel and Davis, and Mott and Spooner formulas. An analysis of the variance of the difference between observed and calculated values obtained with the new formula on IGT coal data indicated that at least 77% is contributed by the variance of the experimental determinations; the remainder can be attributed to the effect of mineral matter and outlying experimental determinations. Application of the formula to coal oxidatively pretreated at 750/sup 0/F to destroy agglomerating properties yields a bias indicating that the heat of formation is higher than expected from elemental and ash composition by about 140 Btu/lb; this is attributed to differences in structure (bonding). The formula gives satisfactory results on higher temperature HYGAS chars, and with application of a bias correction on pretreated coal. Thus, the formula is advantageous for use in the computer modelling of coal conversion processes and for monitoring test data on coal and char.