Fossil vs. Alternative Fuels - Energy Content
Net (low) and gross (high) energy content in fossil and alternative fuels.
Energy content or calorific value is the same as the heat of combustion , and can be calculated from thermodynamical values, or measured in a suitable apparatus:
A known amount of the fuel is burned at constant pressure and under standard conditions (0°C and 1 bar) and the heat released is captured in a known mass of water in a calorimeter. If the initial and final temperatures of the water is measured, the energy released can be calculated using the equation
H = ΔT m Cp (1)
where
H = heat energy absorbed (in J)
ΔT = change in temperature (in °C)
m = mass of water (in g)
Cp = specific heat capacity (4.18 J/g°C for water)
The resulting energy value divided by grams of fuel burned gives the energy content (in J/g).
The combustion process generates water vapor and certain techniques may be used to recover the quantity of heat contained in this water vapor by condensing it.
- Higher Calorific Value (= Gross Calorific Value - GCV = Higher Heating Value - HHV) - the water of combustion is entirely condensed and the heat contained in the water vapor is recovered
- Lower Calorific Value (= Net Calorific Value - NCV = Lower Heating Value - LHV) - the products of combustion contains the water vapor and the heat in the water vapor is not recovered
The table below gives the gross and net heating value of fossil fuels as well as some alternative biobased fuels.
See also Heat of combustion, Fuels - Higher and Lower Calorific Value and Combustion of fuels - CO2emissions.
For full table with Net Heating values - rotate the screen!
| Fuels | Density | Gross Heating Value | Net Heating Value | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mass basis | Volume basis | Mass basis | Volume basis | |||||||||
| Gaseous Fuels @0°C/32°F and 1 atm | kg/m3 | grams/ft3 | MJ/kg | Btu/lb | MJ/m3 | Btu/ft3 | MJ/kg | Btu/lb | MJ/m3 | Btu/ft3 | ||
| Natural gas (95% methane)* | 0.747 | 21.2 | 54.0 | 23,216 | 40.34 | 1,049 | 48.7 | 20,956 | ||||
| Natural gas (US marked)* | 0.777 | 22.0 | 52.2 | 22,453 | 40.60 | 1,089 | 47.1 | 20,267 | 36.65 | 983 | ||
| Hydrogen | 0.09 | 2.55 | 142.2 | 61,127 | 12.79 | 343 | 120.2 | 51,682 | 10.81 | 290 | ||
| Still gas (in refineries) | 1.159 | 32.8 | 51.0 | 21,905 | 59.05 | 1,584 | 46.9 | 20,163 | 54.36 | 1458 | ||
| Liquid Fuels | kg/m3 | grams/gal | MJ/kg | Btu/lb | MJ/m3 | Btu/gal | MJ/kg | Btu/lb | MJ/m3 | Btu/gal | ||
| Crude oil1) | 846 | 3,205 | 45.5 | 19,580 | 38,513 | 138,350 | 42.7 | 18,352 | 36,097 | 129,670 | ||
| Conventional gasoline1) | 744 | 2,819 | 46.5 | 20,007 | 34,613 | 124,340 | 43.4 | 18,679 | 32,317 | 116,090 | ||
| Reformulated or low-sulfur gasoline1) | 747 | 2,830 | 45.4 | 19,533 | 33,920 | 121,848 | 42.4 | 18,211 | 31,624 | 113,601 | ||
| CA reformulated gasoline1) | 746 | 2,828 | 45.6 | 19,595 | 34,010 | 122,174 | 42.5 | 18,272 | 31,715 | 113,927 | ||
| Kerosene1) | 790 | 2,994 | 46.4 | 19,948 | 36,656 | 131,675 | ||||||
| U.S. conventional diesel1) | 836 | 3,167 | 45.8 | 19,676 | 38,243 | 137,380 | 42.8 | 18,397 | 35,757 | 128,450 | ||
| Low-sulfur diesel1) | 846 | 3,206 | 45.6 | 19,594 | 38,552 | 138,490 | 42.6 | 18,320 | 36,046 | 129,487 | ||
| Petroleum naphtha1) | 724 | 2,745 | 48.1 | 20,669 | 34,819 | 125,080 | 44.9 | 19,320 | 32,548 | 116,920 | ||
| NG-based FT naphtha1) | 699 | 2,651 | 47.7 | 20,488 | 33,333 | 119,740 | 44.4 | 19,081 | 31,044 | 111,520 | ||
| Residual oil1) | 990 | 3,752 | 42.2 | 18,147 | 41,787 | 150,110 | 39.5 | 16,968 | 39,071 | 140,352 | ||
| E-Diesel Additives1) | 744 | 2,819 | 46.5 | 20,007 | 34,613 | 124,340 | 43.4 | 18,679 | 32,317 | 116,090 | ||
| Liquefied petroleum gas (LPG)1) | 507 | 1,923 | 50.2 | 21,561 | 25,446 | 91,410 | 46.6 | 20,038 | 23,648 | 84,950 | ||
| Liquefied natural gas (LNG)1) | 428 | 1,621 | 55.2 | 23,734 | 23,612 | 84,820 | 48.6 | 20,908 | 20,800 | 74,720 | ||
| Dimethyl ether (DME)1) | 664 | 2,518 | 31.7 | 13,620 | 21,048 | 75,610 | 28.9 | 12,417 | 19,188 | 68,930 | ||
| Dimethoxy methane (DMM) | 859 | 3,255 | 25.7 | 11,036 | 22,046 | 79,197 | 23.4 | 10,061 | 20,099 | 72,200 | ||
| Methyl ester (biodiesel, BD) | 887 | 3,361 | 40.2 | 17,269 | 35,621 | 127,960 | 37.5 | 16,134 | 33,280 | 119,550 | ||
| Fischer-Tropsch diesel (FTD)1) | 796 | 3,017 | 45.5 | 19,549 | 36,197 | 130,030 | 43.2 | 18,593 | 34,427 | 123,670 | ||
| Ethanol | 788 | 2,988 | 29.8 | 12,832 | 23,531 | 84,530 | 27.0 | 11,587 | 21,248 | 76,330 | ||
| Renewable Diesel I (SuperCetane)1) | 748 | 2,835 | 46.6 | 20,047 | 34,879 | 125,294 | 43.6 | 18,729 | 32,586 | 117,059 | ||
| Renewable Diesel II (UOP-HDO)1) | 778 | 2,948 | 46.8 | 20,128 | 36,416 | 130,817 | 44.0 | 18,908 | 34,209 | 122,887 | ||
| Renewable Gasoline1) | 747 | 2,830 | 46.3 | 19,911 | 34,583 | 124,230 | 43.2 | 18,590 | 32,287 | 115,983 | ||
| Liquid Hydrogen | 71 | 268 | 141.8 | 60,964 | 10,027 | 36,020 | 120.1 | 51,621 | 8,490 | 30,500 | ||
| Methyl tertiary butyl ether (MTBE) | 742 | 2,811 | 38.0 | 16,319 | 28,152 | 101,130 | 35.1 | 15,094 | 26,039 | 93,540 | ||
| Ethyl tertiary butyl ether (ETBE) | 741 | 2,810 | 39.2 | 16,873 | 29,099 | 104,530 | 36.3 | 15,613 | 26,924 | 96,720 | ||
| Tertiary amyl methyl ether (TAME) | 769 | 2,913 | 39.3 | 16,906 | 30,223 | 108,570 | 36.4 | 15,646 | 27,971 | 100,480 | ||
| Butane | 584 | 2,213 | 49.2 | 21,157 | 28,734 | 103,220 | 45.3 | 19,466 | 26,437 | 94,970 | ||
| Isobutane | 559 | 2,118 | 49.1 | 21,108 | 27,437 | 98,560 | 44.9 | 19,287 | 25,071 | 90,060 | ||
| Isobutylene | 594 | 2,253 | 48.2 | 20,739 | 28,675 | 103,010 | 44.8 | 19,271 | 26,646 | 95,720 | ||
| Propane | 507 | 1,920 | 50.2 | 21,597 | 25,449 | 91,420 | 46.3 | 19,904 | 23,453 | 84,250 | ||
| Solid Fuels | MJ/kg | Btu/lb | Btu/ton** | MJ/kg | Btu/lb | Btu/ton | ||||||
| Petroleum coke | 31.3 | 13,460 | 26,920,000 | 29.5 | 12,685 | 25,370,000 | ||||||
| Coal (wet basis) | 24.0 | 10,304 | 20,608,570 | 22.7 | 9,773 | 19,546,300 | ||||||
| Coal (low bituminous) | 28.9 | 12,425 | 24,849,684 | |||||||||
| Coal (bituminous, wet basis) | 27.3 | 11,723 | 23,445,900 | 26.1 | 11,230 | 22,460,600 | ||||||
| Coal (high bituminous) | 36.3 | 15,606 | 31,212,579 | |||||||||
| Coal (anthracite) | 34.6 | 14,875 | 29,750,833 | |||||||||
| Coking coal (wet basis) | 29.9 | 12,840 | 25,679,670 | 28.6 | 12,300 | 24,600,497 | ||||||
| Charcoal (wood) | 34.7 | 14,918 | 29,836,818 | |||||||||
| Farmed trees (dry basis) | 20.6 | 8,852 | 17,703,170 | 19.6 | 8,406 | 16,811,000 | ||||||
| Wood, oak | 18.9 | 8,126 | 16,251,178 | |||||||||
| Wood, locust | 19.7 | 8,470 | 16,939,058 | |||||||||
| Wood, Ponderosa pine | 20 | 8,599 | 17,197,013 | |||||||||
| Wood, redwood | 20.7 | 8,899 | 17,798,909 | |||||||||
| Herbaceous biomass (dry basis) | 18.1 | 7,791 | 15,582,870 | 17.2 | 7,399 | 14,797,555 | ||||||
| Corn stover (dry basis) | 17.4 | 7,487 | 14,974,460 | 16.4 | 7,038 | 14,075,990 | ||||||
| Grass (lawn cuttings) | 19.3 | 8,298 | 16,595,118 | |||||||||
| Forest residue (dry basis) | 16.5 | 7,082 | 14,164,160 | 15.4 | 6,622 | 13,243,490 | ||||||
| Sugar cane bagasse | 16.4 | 7,031 | 14,062,678 | 15.1 | 6,474 | 12,947,318 | ||||||
| Newsprint | 18.6 | 7,997 | 15,993,222 | |||||||||
| Cellulose | 17.3 | 7,438 | 14,875,417 | |||||||||
| * Natural gas composition may vary a lot between different markets ** Short ton, 1 short ton = 2000 lb = 907.18 kg | ||||||||||||
1) Fuels which consist of a mixture of several different compounds may vary in quality between seasons and markeds. The given values are for fuels with the given density. The variation in quality may give heating values within a range 5 -10% higher and lower than the given value. Also the solid fuels will have a similar quality variation for the different classes of fuel.
Key numbers to remember:
Approximate conversion values between some fossil fuel volume, weight and energy units ( using net (=low) heating values) :
- 1 U.S. gallon gasoline = 115000 Btu = 121 MJ = 32 MJ/liter
- 1 boe (barell of oil equivalent) = 42 U.S. gallons = 35 Imperial Gallons = 159 liter = 5.1 GJ = 4.8 million Btu = 1400 kWh
- 1 metric tonne gasoline = 8.44 barrels = 1342 liter = 42.8 GJ
- 1 U.S. gallon diesel = 129000 Btu = 136 MJ = 36 MJ/liter
- 1 liter diesel = 36.0 MJ
- 1 metric tonne coal = 32-35 GJ (bituminous/anthracite) = 27.5 GJ (low-bituminous)
- 1 cubic feet natural gas = 950 Btu
- 1 cubic meter natural gas = 36.5 MJ
