Analysis and significance of prediction models for higher heating value of coal: an updated review

A nation's ability to use its energy resources efficiently and the expansion of its industrial sector are key factors in its prosperity. Most of the industrially developed nations in the world use coal as their main energy source. These resources have been utilized mainly for industrial growth, such as thermal power plants, steel industries, and other associated industries for the industrial revolution. For the exploitation and utilization of these resources, heating value is a significant concern. This can be determined directly or using models framed using readily available variables. Various mathematical models have been developed for estimating coal heating value quickly and precisely. The current review compiles the most recent and well-known models for estimating coal's heating value. Different models have relied upon elemental analysis, proximate analysis, proximate and ultimate analysis, spectroscopy, and other analyses to determine target variables. This compilation shall help the user to identify and apply best suited method, based on concerned organization's economic condition and accessibility to methodology.