This article compares the alternative fuels currently available for use in internal combustion engines, after conversion. Specific focus has been put on home production of the fuel and the amount of emissions.
| ICE fuel | Greenhouse Gas Emissions | Energy output/m³ | Fabrication requirements | Difficulty to convert IC-engine to this fuel | Storability | Toxicity | Remarks |
|---|---|---|---|---|---|---|---|
| Compressed air | Emissionless | ?W/m³ | no land required, only air and accessibility of energy needed | easy, only possible with certain IC engines such as quasiturbine. Other engines can (supposedly) not be converted | long storability | not toxic | Compressed air works more or less as a energy storage, meaning that you need a fair amount of power first to convert to compressed air. Best option if you have a quasiturbine-engine |
| Pure Hydrogen | Water | ?W/m³ | no land required, accessibility of water and electricity (in higher quantities than what is obtained in hydrogen) required. No electricity required if produced by microorganisms.[1][2][3] | intermediate, depends on whether DIY or by kit | short storability; needs to be stored under pressure in tanks to increase gas amounts and thus energy output. This can be done by either carbon nanotube tanks or keratine-based tanks.[4] | not toxic | none |
| Oxyhydrogen | Water | ?W/m³ | no land required, accessibility of water and electricity required. No electricity required if produced by microorganisms.[5][6][7] | intermediate, depends on whether DIY or by kit | ? | not toxic | none |
| Liquid nitrogen | Emissionless | ?W/m³ | no land required, accessibility of water and electricity required. No electricity required if produced by microorganisms. | intermediate, depends on whether DIY or by kit | ? | not toxic | none |
| Water | Emissionless | ?W/m³ | no land required, accessibility of water and energy needed | intermediate, depends on whether DIY or by kit | ? | not toxic | no official documents, could still be a hoax |
| Nitrous oxide | Emissionless | ?W/m³ | no land required, accessibility of ? and energy needed | ? | ? | little toxic | Generally not used as a single fuel, only as an oxidizer (ie by mixing it with a different fuel, increasing the efficiency. Can be used as a monopropellant too though [8][9][10][11] |
| Syngas | Emissionless | ?W/m³ | no land required, accessibility of water and electricity required. Expensive/high-tech concentrating solar power plant (or sunlight similator plant) required though.[12] | intermediate, depends on whether DIY or by kit | ? | not toxic | none |
| Hydrogen peroxide [13](in either nitrogen dioxide, and nitrogen tetroxide-form) | Emissionless | ?W/m³ | no land required, accessibility of water and energy needed | intermediate to hard, depends on whether DIY or by kit | ? | very toxic, make sure to eliminate potential skin contact | hydrogen peroxide may also be mixed with ethanol (ratio 68%-32%)[14][15] |
| Hydrogen or oxyhydrogen-fossil fuel mixture[16] | Yes. ?co² | ?W/m³ | fossil fuels not producible at home, accessibility of water and energy needed | easy, by DIY method or by kit | relative long storage of fossil fuels (several months), hydrogen/oxyhydrogen is made just before use | toxic | Though ICE conversion is easy and relatively cheap to do, the use of the fossil fuels still makes mixture non-self producible and still polluting. Therefore a full hydrogen/oxyhydrogen is always preferred. |
| Wood gas | Yes. ?co² | ?W/m³ | producible at home, accessibility of trees needed | moderate to hard, by DIY method or by kit | wood stores a long time, wood gas is made just before use | ? | Generally quite inefficient, as a lot of heat needs to be generated first to convert the wood into wood gas; however the extra heat might be beneficial to the process too (expands the wood gas), which would mean that not all excess heat is wasted |
| Ethanol, Biomethanol and Butanol fuel | Yes. ?co² | ?W/m³ | arable land required, planted with trees for fruit or wood (depending on whether its used to produce ethanol or methanol/butanol | intermediate to hard, depends on whether DIY or by kit | ? | though ethanol is safe, methanol is very toxic, avoid inhalation, skin contact, ... | although ICE conversion is very easy, much work to produce base fuel itself. Perhaps usable for eco-projects as trees may clear area of possible pollution and as emissions may be directed underground with stationary engines using Carbon capture and storage. Besides using trees, other crops as straw can also be used and converted using elephants yeast.[17][18] |
| Gases as Syngas, Compressed natural gas (CNG) and HCNG | Yes. ?co² | ?W/m³ | access to gas supplies required | intermediate to hard, can be outsourced to professional | ? | ? | access to gas reserves are mostly not available, not worth the conversion due to still fair amounts of pollution |
| Vegetable oils as Jatropha | Yes. ?co² | ?W/m³ | arable land required, planted with trees for wood | intermediate, somewhat harder than ethanol/methanol, ... as the engine needs to be preheated and is best a diesel | ? | not toxic | much work to produce base fuel itself. Perhaps usable for eco-projects as trees
may clear area of possible pollution and as emissions may be directed underground with stationary engines using Carbon capture and storage. Also usable for project combating desertification as japtropha can thrive in sandy/arid environments and as the emissions may again be directed underground (see above) |
| Algae fuel (can be converted to biodiesel and vegetable oil) | Yes. ?co² | ?W/m³ | access to gas supplies required | intermediate, somewhat harder than ethanol/methanol, ... as the engine needs to be preheated and is best a diesel | ? | ? | probably much work to produce base fuel itself. Perhaps usable for eco-projects as algae
may clear a seawater area of possible pollution and as emissions may be directed underground with stationary engines using Carbon capture and storage. |
References
- ↑ Synthetic biology and hydrogen
- ↑ Synthetic biology to make hydrogen
- ↑ Synthetic biology at Berkeley Lab
- ↑ Increasing interior surface and thus hydrogen storage using keratine
- ↑ Synthetic biology and hydrogen
- ↑ Synthetic biology to make hydrogen
- ↑ Synthetic biology at Berkeley Lab
- ↑ NOX as monopropellant 1
- ↑ NOX as monopropellant 2
- ↑ NOX as monopropellant 3
- ↑ NOX as monopropellant 4
- ↑ Syngas production using concentrating solar power plant
- ↑ Hydrogen peroxide in IC engines
- ↑ RD-0120 rocket engine fuel by Energia-Buran described
- ↑ Arcaspace's hydrogen peroxide-oxygen rocket engine fuel described
- ↑ Hydrogen or oxyhydrogen/fossil fuel mix
- ↑ Jack Pronk's elephant yeast
- ↑ Straw to ethanol plant in Sas van Gent
Oxidizers to look into
nitric oxide (reported most stable of the NO's), nitrogen trioxide, nitrogen pentoxide need to be looked into and added if useful.