Gasoline and diesel are still fossil fuel kings of the fuel supply chain but alternative fuels are now swinging the scale more toward green.
A growing number of people believe alternative fuels will have an expanded role in the cars and trucks of tomorrow. According to Larry West, such interest has been spurred by three important considerations:
- Alternative fuels generally have lower vehicle emissions that contribute to smog, air pollution and global warming
- Most alternative fuels don’t come from finite fossil-fuel resources and are sustainable
- Alternative fuels can help nations become more energy independent
With this in mind, we learn that the U.S. Energy Policy Act of 1992 identified eight alternative fuels of note – some that are used, others considered more experimental in nature. Regardless, the fuels on this list have the potential to serve as full or partial alternatives to gasoline and diesel. Here is our Top Eight list of alternative fuels.
An alcohol-based alternative fuel made by fermenting and distilling crops such as corn, barley or wheat. It can be blended with gasoline to increase octane levels and improve emissions quality. Positive: Materials are renewable. Negative: Ethanol subsidies have a negative impact on food prices and availability.
2. Natural Gas
Natural gas is an alternative fuel that burns clean and is already widely available to people in many countries through utilities that provide natural gas to homes and businesses. Positive: Cars and trucks with specially designed engines produce fewer harmful emissions than gasoline or diesel. Negative: Natural gas production creates methane, a greenhouse gas that is 21 times worse for global warming than CO2.
Electricity can be used as a transportation alternative fuel for battery-powered electric and fuel-cell vehicles. Battery powered electric vehicles store power in batteries that are recharged by plugging the vehicle into a standard electrical source. Fuel-cell vehicles run on electricity that is produced through an electrochemical reaction that occurs when hydrogen and oxygen are combined. Positive: Electricity for transportation is highly efficient, and we already have an extensive electricity network. In the case of fuel cells, they produce electricity without combustion or pollution. Negative: Much electricity is generated today from coal or natural gas, leaving a bad carbon footprint. (Nonetheless, electric vehicles are still the greenest option around when it comes to cars.)
Hydrogen can be mixed with natural gas to create an alternative fuel for vehicles that use certain types of internal combustion engines. Hydrogen is also used in fuel-cell vehicles that run on electricity produced by the petrochemical reaction that occurs when hydrogen and oxygen are combined in the fuel “stack.” Positive: No bad emissions. Negative: Cost. And also the lack of fueling infrastructure and difficulty of putting it in place.
Propane—also called liquefied petroleum gas or LPG—is a byproduct of natural gas processing and crude oil refining. Already widely used as a fuel for cooking and heating, propane is also a popular alternative fuel for vehicles. Positive: Propane produces fewer emissions than gasoline, and there is also a highly developed infrastructure for propane transport, storage and distribution. Negative: Natural gas production creates methane, a greenhouse gas that is 21 times worse for global warming than CO2.
Biodiesel is an alternative fuel based on vegetable oils or animal fats, even those recycled after restaurants have used them for cooking. Vehicle engines can be converted to burn biodiesel in its pure form, and biodiesel can also be blended with petroleum diesel and used in unmodified engines. Positive: Biodiesel is safe, biodegradable, reduces air pollutants associated with vehicle emissions, such as particulate matter, carbon monoxide and hydrocarbons. Negative: Limited production and distribution infrastructure.
Methanol, also known as wood alcohol, can be used as an alternative fuel in flexible fuel vehicles that are designed to run on M85, a blend of 85 percent methanol and 15 percent gasoline, but automakers are no longer manufacturing methanol-powered vehicles. Positive: Methanol could become an important alternative fuel in the future as a source of the hydrogen needed to power fuel-cell vehicles. Negative: Automakers are no longer manufacturing methanol-powered vehicles.
8. P-Series Fuels
P-Series fuels are a blend of ethanol, natural gas liquids and methyltetrahydrofuran (MeTHF), a co-solvent derived from biomass. P-Series fuels are clear, high-octane alternative fuels that can be used in flexible fuel vehicles. Positive: P-Series fuels can be used alone or mixed with gasoline in any ratio by simply adding it to the tank. Negative: Manufacturers are not making flexible fuel vehicles.
Photo: horatioNailknot_Rob Elam
Source: Environmental About.com