
doi: 10.1115/1.4050880
Abstract The higher heating value (HHV) of 84 coal samples including hard coals, lignites, and anthracites from Russia, Colombia, South Africa, Turkey, and Ukrania was predicted by multilinear regression (MLR) method based on proximate and ultimate analysis data. The prediction accuracy of the correlation equations was tested by Analysis of variance method. The significance of the predictive parameters was studied considering R2, adj. R2, standard error, F-values, and p-values. Although relationships between HHV and any of the single parameters were almost irregular, MLR provided a reasonable correlation. It was also found out that ultimate analysis parameters (C, H, and N) played a more significant role than the proximate analysis parameters (fixed carbon (FC), volatile matter (VM), and ash) in predicting the HHV. Particularly, FC content was seen inefficient parameter when elemental C content existed in the regression equation. The elimination of proximate analysis parameters from the equation made the elemental C content the most dominant parameter with by-far very low p-values. For hardcoals, adj. R2 of the equation with three parameters (HHV = 87.801(C) + 132.207(H) − 77.929(S)) was slightly higher than that of HHV = 11.421(Ash) + 22.135(VM) + 19.154(FC) + 70.764(C) + 7.552(H) − 53.782(S).
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 4 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
