Here is a list of Alternative fuels and a VERY BASIC summary of each, there are tons and tons of more article about alternative fuels, conversion kits for your very own vehicles, and information about our enviorment that alot of people may not even realize. Read up, educate yourself.
Compressed Natural Gas: Natural gas comes from underground and is made up of around 95% methane. Methane is a hydrocarbon, meaning its molecules are made up of hydrogen and carbon atoms. Its simple, one-carbon molecular structure (CH4) makes possible its nearly complete combustion. The remaining 5% is made up of various gases along with small amounts of water vapor. These other gases include butane, propane, ethane and other trace gases.
Cars, vans, buses and small trucks generally use natural gas that has been compressed (hence the name compressed natural gas or CNG) and stored in high-pressure cylinders. Alternatively, gas may be compressed by the dispenser unit for overnight fueling. The practically complete combustion ensures CNG is an extremely clean burning fuel unlike gasoline or diesel.
Liquefied Natural Gas: Liquefied natural gas (LNG) is made by refrigerating natural gas to minus 260 degrees Fahrenheit (260 degrees below zero!) to condense it into a liquid. This process removes most of the water vapor, butane, propane, and other trace gases, that are usually included in ordinary natural gas. The resulting LNG is usually more than 98 percent pure methane.
The liquid form is much more dense than natural gas or CNG. It has much more energy for the amount of space it takes up. So, much more energy can be stored in the same amount of space on a car or truck. That means LNG is good for large trucks that need to go a long distance before they stop for more fuel.
Liquefied Petroleum Gas / Propane: Liquefied petroleum gas (LPG), as the name suggests, is partly a byproduct of petroleum refining; in California the state's oil refineries are the main source, but nationwide only about 45% of LPG comes from petroleum refining, and the majority comes from natural gas processing. LPG consists of hydrocarbons, which are gases at room temperature, but turn to liquid when they are compressed. LPG is stored in special tanks that keep it under pressure, so it stays a liquid. The pressure of these tanks is usually about 200 pounds per square inch (abbreviated "psi"). The main constituent of LPG is propane; the name by which it is often referred to.
Because LPG enters the engine as a vapor, it doesn't wash oil off cylinder walls or dilute the oil when the engine is cold, and it also doesn't put carbon particles and sulfuric acid into the oil. Thus an engine that runs on propane can expect a longer service life and reduced maintenance costs. LPG is also cheaper than gasoline in most places.
Alcohol Based Fuels:
Methanol: Methanol can be produced from a variety of sources such as biomass (this is why it is sometimes called "wood alcohol") and coal, but today methanol is almost all made from natural gas. Methanol is a liquid at normal temperatures and pressures and is therefore, much easier to transport long distances than other forms of natural gas (CNG & LNG).
Methanol is more corrosive than gasoline (though it is less toxic, and non carcinogenic), so vehicles and refueling stations need materials that can withstand attack by the fuel. Special oil additives are necessary in order to protect the engine. The richer fuel/air mixture needed by methanol also means that a given volume of gasoline will take you about 70% farther than the same tank full of M85. Most automakers have at least partially compensated for this by putting a larger fuel tank in their M85 vehicles.
Methanol is most commonly used in a mixture with 15% gasoline to correct for two disadvantages of pure methanol. First, a methanol flame is colorless, so gasoline is added to give the flame some color so rescuers can tell if a fire is present should an M85 vehicle get into a crash. Second, methanol, being a pure chemical compound, has a single boiling point, so that it can cause cold-start problems in cold weather, or vapor lock in hot.
Ethanol: Ethanol (sometimes called grain alcohol) is generally made in the US from corn (a grain), but can also be made from biomass. As an alternative motor vehicle fuel, it is usually blended in a mixture of 85% ethanol, 15% unleaded gasoline, hence the name E85.
Ethanol contributes nothing in itself to global warming concerns. Like methanol, it can be blended with any amount of gasoline in the tank of a flex-fuel vehicle. In fact, starting with the 1999 model year, some automakers are making every one of certain vehicle models capable of using E85 in any mixture with gasoline, at no extra charge. Thus buyers will not have to do anything extra at all to have a vehicle capable of using an alternative fuel, though they will still have to find an E85 fueling station to take advantage of that capability.
Biodiesel: Biodiesel commonly uses soybean or canola oil as its base, but animal fat or recycled cooking oil can also be used. It is made through a process called transesterification, which makes these resources into esterified oil. This product can be used as diesel fuel, or mixed with regular diesel fuel. As it is made from agricultural resources, biodiesel is completely biodegradable and non-toxic to humans.
To speed its market introduction, and minimize its additional cost over petroleum diesel fuel, the most common commercial product is B20, a blend of 20% biodiesel and 80% petroleum diesel fuel. B20 requires absolutely no change in the storage or dispensing infrastructure and facilities that handle petroleum diesel fuel. Even "neat" biodiesel (or "B100") would only require minor changes in some materials such as those used for seals and hoses. Both B20 and B100 can be used in any standard unmodified diesel engine making the switch to an alternative fuel simple!
Electricity: Electric vehicles (EV's) are generally divided into battery and hybrid classes. Hybrid electric vehicles can be designed to run on any fuel, including gasoline or diesel as well as alternative fuels. Hybrids are self-contained units for maximum efficiency - when engine demand is low (starting, stopping) hybrids are powered by an electric motor, during normal traveling the gasoline engine engages, and when decelerating or braking the wheels drive he electric motor, which acts as a generator and recharges the battery.
Battery-electric vehicles don't burn gasoline in an engine, they use electricity stored on the car in batteries. Sometimes, 12 or 24 batteries, or more, are needed to power the car. Just like a remote-controlled model electric car, EV's have an electric motor that turns the wheels and a battery to run that motor. To charge an EV's batteries, the car is plugged in to ordinary 110-volt wall sockets and/or 220-volt appliance outlets. Modern production EV's are mostly being built with specialized connectors that can speed up the "refueling" process and increase safety. You can install a recharging station with the right kind of connector for your vehicle in your garage, and in some cities recharging stations that offer the most popular connectors are being installed in public places.
Fuel Cells: Fuel cells combine oxygen from the air with hydrogen from the vehicle's fuel tank to produce electricity. When oxygen and hydrogen are combined all they produce is energy and water (H2O). The electricity then powers an electric motor, just as in battery-powered vehicle. This process is completed without any burning (combustion).
Fuel cell vehicles are considered by many to be the vehicles of the future in terms of their zero emissions. However, there is still much work to be done to ensure the vehicles can operate as efficiently and reliably as gasoline/diesel cars, and to ensure the hydrogen can be stored on-board in an entirely safe manner.
Hydrogen gas can come from gaseous or liquid hydrogen stored on the vehicle. To carry gaseous hydrogen on a vehicle, it must be compressed. When compressed (usually to a pressure of about 3000 pounds per square inch), it must be stored in special high-pressure containers. The other way is to store it in liquid form, which is chilled and compressed. Liquid hydrogen is very, very cold--more than 423.2 degrees Fahrenheit below zero!
The only way to change our future, is by protecting what we have now, our planet is a very precious thing that we do take granted for most of the time. I am very pleased to see alot of people outreaching trying to make a difference... Shit even on MTV's Pimp My Ride on Earth Day they built an older-gen Muscle Car and put a TT Diesel motor in it that runs off of bio-fuel which was pretty amazing, it ran a 12.3 second 1/4 mile which is fucking awesome
But yeah, there will be more threads on this eventually, just stick around.