Energy content of biofuel
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[edit] A table of energy content and CO2 output of common fuels
Energy is the ability to do work. Per kilogram of mass, different substances can do different amounts of work.[1] Of course to do work we usually use a machine of some type. These machines vary in efficiency, or useful work done, and none are 100% efficient. Thus the amount of useful work actually performed by these substances will never totally match these results. However this table tells me that men are really amounts of these substances which could be equivalent in producing the required result (moving a car, heating a home, etc.).
In the example of the first two entries, bagasse (cane stalks) has 9.6 MJ/kg (megajoules per kilogram) and chaff (seed casings) has an energy content of 14.6 MJ/kg. In other words 1 kg of chaff as a fuel would have 14.6-9.6, or 5 MJ more energy per kilogram energy content and potential work output than bagasse.
The next column in the table (3) is the energy content per liter of volume, which is useful for liquid fuels.
The next column (4) contains the ratio of CO2 mass produced to the mass of the fuel. For example bagasse has a ratio of 1.3 which means 1.3 kg of CO2 will be produced for every 1 kg of bagasse used as fuel.
The last column (5), Energy in MJ per kg CO2 produced (MJ/kg) lists the energy produced per kilogram of CO2 produced. This is a measure of the potential environmental impact of the use of the substance as a fuel with respect to the release of CO2. The more CO2 released the worse it is for the environment. Thus a higher number in this column is better for the environment because we get more energy per kg of CO2 produced. For example gasoline produces 13.64-14.64 MJ/kg of CO2 but methane produces 20.05-20.30 MJ/kg of energy, or nearly 50% more energy for the same CO2 production.
| Fuel Type | Specific Energy Density (MJ/kg) |
Volumetric Energy Density (MJ/L) |
CO2 Gas made from Fuel Used (kg/kg) |
Energy per CO2 (MJ/kg) |
|---|---|---|---|---|
| Solid Fuels | ||||
| Bagasse (Cane Stalks) | 9.6 | ~+40%(C6H10O5)n+15%(C26H42O21)n+15%(C9H10O2)n1.30 | 7.41 | |
| Chaff (Seed Casings) | 14.6 | [Please insert average composition here] | ||
| Animal Dung/Manure | [1] 10-[2] 15 | [Please insert average composition here] | ||
| Dried plants (C6H10O5)n | 10 – 16 | 1.6 - 16.64 | IF50%(C6H10O5)n+25%(C26H42O21)n+25%(C10H12O3)n1.84 | 5.44-8.70 |
| Wood fuel (C6H10O5)n | 16 – 21 | [3] 2.56 - 21.84 | IF45%(C6H10O5)n+25%(C26H42O21)n+30%(C10H12O3)n1.88 | 8.51-11.17 |
| Charcoal | 30 | 85-98% Carbon+VOC+Ash 3.63 | 8.27 | |
| Liquid Fuels | ||||
| Pyrolysis oil | 17.5 | 21.35 | (Assumption Of Fuel: Carbon Content = 23% w/w) 0.84 | 20.77 |
| Methanol (CH3-OH) | 19.9 – 22.7 | 15.9 | 1.37 | 14.49-16.53 |
| Ethanol (CH3-CH2-OH) | 23.4 – 26.8 | 18.4 - 21.2 | 1.91 | 12.25-14.03 |
| EcaleneTM | 28.4 | 22.7 | 75%C2H6O+9%C3H8O+7%C4H10O+5%C5H12O+4%Hx 2.03 | 14.02 |
| Butanol(CH3-(CH2)3-OH) | 36 | 29.2 | 2.37 | 15.16 |
| Fat | 37.656 | 31.68 | [Please insert average composition here] | |
| Biodiesel | 37.8 | 33.3 – 35.7 | ~2.85 | ~13.26 |
| Sunflower oil (C18H32O2) | [4] 39.49 | 33.18 | (12%(C16H32O2)+16%(C18H34O2)+71%(LA)+1%(ALA))2.81 | 14.04 |
| Castor oil (C18H34O3) | [5] 39.5 | 33.21 | (1%PA+1%SA+89.5%ROA+3%OA+4.2%LA+0.3%ALA)2.67 | 14.80 |
| Olive oil (C18H34O2) | 39.25 - 39.82 | 33 - 33.48 | (15%(C16H32O2)+75%(C18H34O2)+9%(LA)+1%(ALA))2.80 | 14.03 |
| Gaseous Fuels | ||||
| Methane (CH4) | 55 – 55.7 | (Liquified) 23.0 – 23.3 | (Methane leak exerts 23 × greenhouse effect of CO2) 2.74 | 20.05-20.30 |
| Hydrogen (H2) | 120 – 142 | (Liquified) 8.5 – 10.1 | (Hydrogen leak slightly catalyzes ozone depletion) 0.0 | |
| Fossil Fuels (comparison) | ||||
| Coal | 29.3 – 33.5 | 39.85 - 74.43 | (Not Counting:CO, NOx, Sulfates & Particulates) ~3.59 | ~8.16-9.33 |
| Crude Oil | 41.868 | 28 – 31.4 | (Not Counting:CO,NOx,Sulfates & Particulates) ~3.4 | ~12.31 |
| Gasoline | 45 – 48.3 | 32 – 34.8 | (Not Counting:CO,NOx,Sulfates & Particulates) ~3.30 | ~13.64-14.64 |
| Diesel | 48.1 | 40.3 | (Not Counting:CO,NOx,Sulfates & Particulates) ~3.4 | ~14.15 |
| Natural Gas | 38 – 50 | (Liquified) 25.5 – 28.7 | (Ethane, Propane & Butane N/C:CO,NOx & Sulfates) ~3.00 | ~12.67-16.67 |
| Ethane (CH3-CH3) | 51.9 | (Liquified) ~24.0 | 2.93 | 17.71 |
| Nuclear fuels (comparison) | ||||
| Uranium-235 (235U) | 77,000,000 | (Pure)1,470,700,000 | [Greater for lower ore conc.(Mining, Refining, Moving)] 0.0 | ~55[2] - ~90[3] |
| Nuclear fusion (2H-3H) | 300,000,000 | (Liquified)53,414,377.6 | (Sea-Bed Hydrogen-Isotope Mining-Method Dependent) 0.0 | |
| Fuel Cell Energy Storage (comparison) | ||||
| Direct-Methanol | 4.5466 | [6] 3.6 | ~1.37 | ~3.31 |
| Proton-Exchange (R&D) | up to 5.68 | up to 4.5 | (IFF Fuel is recycled) 0.0 | |
| Sodium Hydride (R&D) | up to 11.13 | up to 10.24 | (Bladder for Sodium Oxide Recycling) 0.0 | |
| Battery Energy Storage (comparison) | ||||
| Lead-acid battery | 0.108 | ~0.1 | (200-600 Deep-Cycle Tolerance) 0.0 | |
| Nickel-iron battery | [7] 0.0487 - 0.1127 | 0.0658 - 0.1772 | (<40y Life)(2k-3k Cycle Tolerance IF no Memory effect) 0.0 | |
| Nickel-cadmium battery | 0.162 - 0.288 | ~0.24 | (1k-1.5k Cycle Tolerance IF no Memory effect) 0.0 | |
| Nickel metal hydride | 0.22 - 0.324 | 0.36 | (300-500 Cycle Tolerance IF no Memory effect) 0.0 | |
| Super iron battery | 0.33 | [8] (1.5 * NiMH) 0.54 | [9] (~300 Deep-Cycle Tolerance) 0.0 | |
| Zinc-air battery | 0.396 - 0.72 | [10] 0.5924 - 0.8442 | (Recyclable by Smelting & Remixing, not Recharging) 0.0 | |
| Lithium ion battery | 0.54 - 0.72 | 0.9 - 1.9 | (3-5 y Life) (500-1k Deep-Cycle Tolerance) 0.0 | |
| Lithium-Ion-Polymer | 0.65 - 0.87 | (1.2 * Li-Ion)1.08 - 2.28 | (3-5 y Life) (300-500 Deep-Cycle Tolerance) 0.0 | |
| Lithium iron phosphate battery | ||||
| DURACELL Zinc-Air | 1.0584 - 1.5912 | 5.148 - 6.3216 | (1-3 y Shelf-life) (Recyclable not Rechargeable) 0.0 | |
| Aluminium battery | 1.8 - 4.788 | 7.56 | (10-30 y Life) (3k+ Deep-Cycle Tolerance) 0.0 | |
| PolyPlusBC Li-Aircell | 3.6 - 32.4 | 3.6 - 17.64 | (May be Rechargeable)(Might leak sulfates) 0.0 | |
[edit] Notes
- While all CO2 gas output ratios are calculated to within a less than 1% margin of error(assuming total oxidation of the carbon content of fuel), ratios preceded by a Tilde (~) indicate a margin of error of up to (but no greater than) 9%. Ratios listed do not include emissions from fuelPlant cultivation/Mining, Purification/Refining & Transportation. Fuel availability is typically 74-84.3% NET from source Energy Balance.
- While Uranium-235 (235U) fission produces no CO2 gas directly, the indirect fossil fuel burning processes of Mining, Milling, Refining, Moving & Radioactive waste disposal, etc. of intermediate to low-grade uranium ore concentrations produces some amount of carbon dioxide. Studies vary as to how much carbon dioxide is emitted. The United Nations Intergovernmental Panel on Climate Change reports that nuclear produces approximately 40 g of CO2 per kilowatt hour (11 g/MJ, equivalent to 90 MJ/kg CO2e).[3] A meta-analysis of a number of studies of nuclear CO2 lifecycle emissions by academic Benjamin K. Sovacool finds nuclear on average produces 66 g of CO2 per kilowatt hour (18.3 g/MJ, equivalent to 55 MJ/kg CO2e).[2] One Australian professor claims that nuclear power produces the equivalent CO2 gas emissions per MJ of net-output-energy of a Natural Gas fired power station. Prof.Mark Diesendorf, Inst. of Environmental Studies, UNSW.
[edit] Yields of common crops associated with biofuels production
| Crop | Oil (kg/ha) |
Oil (L/ha) |
Oil (lb/acre) |
Oil (US gal/acre) |
Oil per seeds (kg/100 kg) |
Melting Range (°C) | Iodine number |
Cetane number |
||
|---|---|---|---|---|---|---|---|---|---|---|
| Oil / Fat |
Methyl Ester |
Ethyl Ester |
||||||||
| Groundnut | (Kernel)42 | |||||||||
| Copra | 62 | |||||||||
| Tallow | 35 - 42 | 16 | 12 | 40 - 60 | 75 | |||||
| Lard | 32 - 36 | 14 | 10 | 60 - 70 | 65 | |||||
| Corn (maize) | 145 | 172 | 129 | 18 | -5 | -10 | -12 | 115 - 124 | 53 | |
| Cashew nut | 148 | 176 | 132 | 19 | ||||||
| Oats | 183 | 217 | 163 | 23 | ||||||
| Lupine | 195 | 232 | 175 | 25 | ||||||
| Kenaf | 230 | 273 | 205 | 29 | ||||||
| Calendula | 256 | 305 | 229 | 33 | ||||||
| Cotton | 273 | 325 | 244 | 35 | (Seed)13 | -1 - 0 | -5 | -8 | 100 - 115 | 55 |
| Hemp | 305 | 363 | 272 | 39 | ||||||
| Soybean | 375 | 446 | 335 | 48 | 14 | -16 - -12 | -10 | -12 | 125 - 140 | 53 |
| Coffee | 386 | 459 | 345 | 49 | ||||||
| Linseed (flax) | 402 | 478 | 359 | 51 | -24 | 178 | ||||
| Hazelnuts | 405 | 482 | 362 | 51 | ||||||
| Euphorbia | 440 | 524 | 393 | 56 | ||||||
| Pumpkin seed | 449 | 534 | 401 | 57 | ||||||
| Coriander | 450 | 536 | 402 | 57 | ||||||
| Mustard seed | 481 | 572 | 430 | 61 | 35 | |||||
| Camelina | 490 | 583 | 438 | 62 | ||||||
| Sesame | 585 | 696 | 522 | 74 | 50 | |||||
| Safflower | 655 | 779 | 585 | 83 | ||||||
| Rice | 696 | 828 | 622 | 88 | ||||||
| Tung oil tree | 790 | 940 | 705 | 100 | -2.5 | 168 | ||||
| Sunflowers | 800 | 952 | 714 | 102 | 32 | -18 - -17 | -12 | -14 | 125 - 135 | 52 |
| Cocoa (cacao) | 863 | 1,026 | 771 | 110 | ||||||
| Peanuts | 890 | 1,059 | 795 | 113 | 3 | 93 | ||||
| Opium poppy | 978 | 1,163 | 873 | 124 | ||||||
| Rapeseed | 1,000 | 1,190 | 893 | 127 | 37 | -10 - 5 | -10 - 0 | -12 - -2 | 97 - 115 | 55 - 58 |
| Olives | 1,019 | 1,212 | 910 | 129 | -12 - -6 | -6 | -8 | 77 - 94 | 60 | |
| Castor beans | 1,188 | 1,413 | 1,061 | 151 | (Seed)50 | -18 | 85 | |||
| Pecan nuts | 1,505 | 1,791 | 1,344 | 191 | ||||||
| Jojoba | 1,528 | 1,818 | 1,365 | 194 | ||||||
| Jatropha | 1,590 | 1,892 | 1,420 | 202 | ||||||
| Macadamia nuts | 1,887 | 2,246 | 1,685 | 240 | ||||||
| Brazil nuts | 2,010 | 2,392 | 1,795 | 255 | ||||||
| Avocado | 2,217 | 2,638 | 1,980 | 282 | ||||||
| Coconut | 2,260 | 2,689 | 2,018 | 287 | 20 - 25 | -9 | -6 | 8 - 10 | 70 | |
| Chinese Tallow | 4,700 | 500 | ||||||||
| Oil palm | 5,000 | 5,950 | 4,465 | 635 | 20-(Kernal)36 | 20 - 40 | -8 - 21 | -8 - 18 | 12 - 95 | 65 - 85 |
| Algae | 95,000 | 10,000 | ||||||||
| Crop | Oil (kg/ha) |
Oil (L/ha) |
Oil (lb/acre) |
Oil (US gal/acre) |
Oil per seeds (kg/100 kg) |
Melting Range (°C) | Iodine number |
Cetane number |
||
| Oil / Fat |
Methyl Ester |
Ethyl Ester |
||||||||
Oil per seeds = Typical oil extraction from 100 kg of oil seeds
- Note: Chinese Tallow (Sapium sebiferum, or Tradica Sebifera) is also known as the "Popcorn Tree".
Source: Used with permission from The Global Petroleum Club
[edit] See also
[edit] References
- ^ "Bioenergy Conversion Factors". Oak Ridge National Laboratory. http://bioenergy.ornl.gov/papers/misc/energy_conv.html. Retrieved 2008-05-18.
- ^ a b Benjamin K. Sovacool.Valuing the greenhouse gas emissions from nuclear power: A critical survey. Energy Policy, Vol. 36, 2008, p. 2950.
- ^ a b Intergovernmental Panel on Climate Change (2007). "4.3.2 Nuclear energy". IPCC Fourth Assessment Report: Climate Change 2007, Working Group III Mitigation of Climate Change. http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch4s4-3-2.html. Retrieved 2011-02-07.
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