Question

Describe the difference between gasohol, E-85 and B-20. On what type of devices can they be used , In what states are they use, What requirements must be met for their use.

Answer 1

Gasohol is a term used for the mixture of 10% ethyl alcohol (also called ethanol or grain alcohol) with gasoline . Ethanol raises the octane rating of lead-free automobile fuel and significantly decreases the carbon monoxide released from tailpipes. It has also been promoted as a means of reducing corn surpluses. Ethanol also raises the vapor pressure of gasoline, and it has been reported to increase the release of "evaporative" volatile hydrocarbons from the fuel system and oxides of nitrogen from the exhaust. These substances are components of urban smog , and thus the role of ethanol in reducing pollution is controversial.

E85 is an abbreviation typically referring to an ethanol fuel blend of 85% ethanol fuel and 15% gasoline or other hydrocarbon by volume. In the United States, the exact ratio of fuel ethanol to hydrocarbon may vary according to ASTM 5798 that specifies the allowable ethanol content in E85 as ranging from 51% to 83%. This is due to the lower heating value of neat ethanol making it difficult to crank engines in relatively cold climates without pre-heating air intake, faster cranking, or mixing varying fractions of gasoline according to climate. Cold cranking in cold climates is the primary reason ethanol fuel is blended with any gasoline fraction.

B20 Biodiesel is a common biofuel blend which consists of up to 20 percent Biodiesel and 80 percent petroleum diesel. Representing a good balance of cost, emissions, cold-weather performance, materials compatibility, and ability to act as a solvent, B20 is increasingly popular with fuel retailers and fleets. Regulated fleets that use biodiesel blends of 20% (B20) or higher qualify for biodiesel fuel use credits under the Energy Policy Act of 1992.

Requirements:

Engine Modifications for Ethanol blends
Changes to cylinder walls, cylinder heads, valves and valve seats, Changes to pistons, piston rings, intake manifolds and carburettors, and Nickel plating of steel fuel lines and fuel tanks to prevent ethanol E20 corrosion and Higher fuel flowrate injectors to compensate for oxygenate qualities of ethanol.

A flexible-fuel vehicle (FFV) or dual-fuel vehicle (colloquially called a flex-fuel vehicle) is an alternative fuel vehicle with an internal combustion engine designed to run on more than one fuel, usually gasoline blended with either ethanol or methanol fuel, and both fuels are stored in the same common tank.

Unlike E85 ethanol which requires a “Flex Fuel” engine modification in order to burn ethanol, all diesel engines can run biodiesel. Biodiesel is chemically compatible with diesel fuel, and the diesel engine running it doesn’t know the difference. There are some minor exceptions to this, but most of them are not applicable to modern diesel engines.