JMU AFV Lab Blog

I came across this item on the About.com Hybrid Cars & Alt Fuel blog this morning.  It includes a table that lists the energy equivalents of most popular transportation energy sources. It may be of use in evaluating the MPGe (Miles Per Gallon Equivalent) of alternative fuels and thus facilitating an “apples to apples” comparison of alternative fuels.  Go to http://alternativefuels.about.com/od/resources/a/gge.htm?nl=1 to read the details.

Energy Equivalency Calculation

Using fuel energy equivalents provides the user with a comparison tool for gauging various fuels against a known constant that has relative meaning. A common method of measurement is the Gasoline Gallon Equivalent. The chart at the bottom of this page arrives at the equivalent measurement by comparing the BTU content per unit of each fuel type and then calculating the ratio.

What’s a BTU?

As a basis for determining energy content of a fuel, it is helpful to understand exactly what a BTU (British Thermal Unit) is. Its scientific definition goes something like this: British Thermal Unit - The amount of heat (energy) required to raise the temperature of 1 pound of water by 1 degree Fahrenheit.

Think of it this way: it’s basically a standard. Just as PSI (pounds per square inch) is a standard for measuring pressure, so too is a BTU a standard for measuring energy content.
See GGE conversion chart below

Source: http://alternativefuels.about.com/od/resources/a/gge.htm?nl=1

Came across this article this morning.  According to the article, …1.5-1.6 more units of energy are derived from ethanol than are used to produce it. Comments?

New Research Supports Ethanol Production
09/23/2008

Ken Cassmen, director of the Nebraska Center for Energy Sciences Research says – recent research, conducted at the University, clearly shows that estimates for the energy balance of corn-based ethanol are much more favorable – in fact 2-3 times more favorable than previous estimates. Cassman points out - it is important to understand that ethanol has a substantial net positive direct energy balance – that 1.5-1.6 more units of energy are derived from ethanol than are used to produce it.

Cassmen added - we estimate that 13 gallons of ethanol are produced for every gallon of petroleum used in the production life cycle for corn ethanol. Alan Tiemann, a member of the Nebraska Corn Board, added that greenhouse gas emission reductions are also more favorable than previous estimates when compared directly to corn and ethanol production.

Compared to just five years ago, Tiemann points out, ethanol plants produce 15 percent more ethanol from a bushel of corn and use about 20 percent less energy in the process. At the same time, corn growers are more efficient, producing more corn per acre and using less energy to do so.

Source: http://www.hoosieragtoday.com/wire/news/01502_energy_study_180658.php

I thought you may be interested in this from Ford.  To me, it is a modern incarnation of an older idea.  Back in the Fifties and Sixties, a few hotrodders used “water injection” to accomplish the same thing, namely cooling the combustion chamber to combat detonation, thus allowing higher compression.  Ford is using ethanol instead of water, accomplishing the same thing but getting heat from the combustion of the ethanol instead of absorbing heat from the vaporization of the water.  I also found it fascinating that they are using direct injection instead of port injection.  With a few exceptions, direct injection has heretofore been the sole province of diesels.  Go to http://reviews.cnet.com/8301-13746_7-10030963-48.html to read the full article.

Below is an excerpt from the article:

We haven’t been too excited about Ford’s Ecoboost tech, simply because it’s not really new tech. However, Ford’s next evolution of Ecoboost, code-named Bobcat, might be worth getting worked up about.

According to sources at PickupTrucks.com, the Bobcat is essentially a turbocharged engine running at a high compression ratio. Typically, this combination results in disaster, but Ford’s system has a trick up its sleeve in the form of ethanol injection.

The Bobcat builds on Ford’s Ecoboost engines by including a direct injected ethanol nozzle that adds small amounts of ethanol to the standard port injected air/fuel mixture. The ethanol cools the combustion chamber to prevent premature detonation, allowing the turbocharged engine to run extreme compression ratios.

The system promises 5 to 10 percent greater fuel economy than EcoBoost engines, which already promise a 20 percent increase over Ford’s traditional engines. Turbodiesel enthusiasts already know that high compression plus a turbo equals gobs of torque, which is why the Bobcat is speculated to be a potential replacement for the large diesel power plants that power Ford’s heavy- and super-duty trucks. A 5.0-liter turbo V-8 with ethanol boost could be rated at 500 horsepower and 700 foot-pounds of torque.

With the system’s lower entry cost combined with gasoline’s consistently lower cost per gallon, this system could be a viable alternative to diesel engines in the big trucks of the future.

Ford’s Bobcat engine includes standard port injected gasoline supplemented by ethanol direct injection.

(Credit: PickupTrucks.com )