estimating the higher heating value of solid, liquid, and natural gas fossil fuels

Due to the increasing demands for energy sources worldwide, particularly in the industry, residential, and transportation sectors, it is necessary to review how abundant and cheap energy sources are utilized. renewable energies such as solar, geothermal, wind, and other shapes have not yet reached the expected utilization, especially in iran. therefore, it is still necessary to focus on fossil fuels utilization as they are one of the most influential factors in energy depletion and climate change. assessment of energy conversion systems which use fossil fuels as primary energy sources strongly depend on the appropriate evaluation of the heating values of the fuel used. in this research, the higher heating values (hhvs) of fossil fuels in all three forms of solid, liquid, and natural gas is calculated using an analytical approach and compared with the available empirical or quasi-experimental relations. the obtained data help engineers correctly assess their energy systems performance.