Net heating value

Weight net heating values NHV of pure organic compounds at 25°C and I bar abs. Sources for hydrocarbons TRC, for others DIPPR (see chapter 4). 

Weight and volume net heating values of commercial motor fuels (average values). 

The moisture content of freshly mined lignitic coals can be as high as 73%, but it is usually 30—65%. The more mature, consoHdated coals have lower moisture contents and thus a higher heating value. Figure 2 shows moisture and ash contents, as well as net heating values for lignitic coals from the world s principal deposits (19). 

Fuel. Propylene has a net heating value of 45.8 MJ/kg (19,700 Btu/lb) and is often contained in refinery fuel-gas streams. However, propylene is diverted from streams for refinery fuel use in large quantities only when economics for other uses are unfavorable, or equipment for propylene recovery does not exist or is limited in capacity. Propylene is also contained in Hquid petroleum gas (LPG), but is limited to a maximum concentration of 5 vol % in certain grades (83) (see Liquefied PETROLEUM gas). 

Gas Component Net Heating Value Btu/SCF SCF/Gallon Equiv[Pg.251]

The heat of combustion is a product of the amount of fuel consumed and the net heating value of the fuel. The heater s efficiency is a function of the flue-gas stack temperature, the excess air or oxygen, and the ambient-heat losses from the firebox and the convective-section structures. 

Gross and net heating values are given in Appendix A for the usual components of natural gas in terms of BTU per cubic foot of ideal gas at standard conditions. The values in Appendix A are on a dry basis. The heating value of an ideal gas is calculated as... 

Equation 6-17 can be used to calculate gross heating value or net heating value. In either case, the values must be converted from ideal gas to real gas at standard conditions. This is done by dividing the ideal value by compressibility factor of the gas at standard conditions. 

Net heating value (dry) may be converted into net heating value (wet)... 

Coal cost estimated at eight dollars per equivalent fuel oil barrel. (Net heating value of six million British thermal units.)... 

In Europe and in other countries where the metric system is used, natural gas calorimeters are calibrated in megajoule units, and in the United States in Btu units. The output of the calorimeter may represent the gross calorific value (sometimes referred to as upper heating value or gross heating value), the net calorific value (sometimes referred to as lower heating value or net heating value), or the Wobbe index. 

Reaction upon which net heating value is based ... 

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