[Vwdiesel] Midshipmen design engines that run on diesel, cooking oil

[mikitka]

Baltimore Sun
April 1, 2007

Project's Fuel Comes With A Side Of Dinner

Midshipmen design engines that run on diesel, cooking
oil

By Bradley Olson, Sun reporter

If you think your thesis in college was grueling, try
this out: Take a go-kart and modify its engine so it
can run on both diesel fuel and used cooking oil, the
kind with chunks of fried stuff in it.

But that's not all. For a handful of Naval Academy
seniors trying to complete their "capstone" mechanical
engineering project, the challenge requires them to
build an engine that can power the go-cart on diesel
fuel from their engineering building to the dining
hall. Once there, they have to get cooking oil used
that day to make food for 4,300 midshipmen, put the
oil - forgotten chicken nuggets and all - into a fuel
tank, and drive away.

While about 60 midshipmen last semester modified used
cooking oil in a chemistry lab, turning it into a
biodiesel compound that could work in any diesel
engine, this group of midshipmen worked to make an
engine that can take the grease and make it into a
usable fuel, no lab required.

"This is something real," said Maggie Hollyfield, 22,
a platoon commander from DeSoto, Texas. "Unlike all
the little labs and stuff we did beforehand, we're
actually getting to apply something we've learned in
the classroom. I've learned a lot."

The project is one of many hands-on activities
midshipmen undertake, such as building satellites that
launch with NASA shuttles, designing erosion control
systems on the Chesapeake Bay and making flying robots
or super-fast go-karts that enter competitions around
the country.

Their efforts, not unlike capstone projects that
students complete at other major engineering
universities, form a critical part of their four-year
education, and one that has important real-world
applications, since the Navy is the largest diesel
fuel user in the world.

This week, students gushed about the possibility,
knowing that if the engines of deployed ships could
work on cooking oil, the Navy could save billions.
Because so much vegetable oil is sent overseas for
sailors' food, it would need to buy less petroleum
diesel and avoid the high costs of disposing of used
oil, without harming the environment.

Although it isn't widely known, the Navy is among the
world's foremost proponents of biodiesel. In early
2005, the service began to require use of the fuel
where it's widely available in some vehicles, and
several bases have made waves by building
mini-refineries for recycling cooking oil into
biodiesel.

But Patrick Caton, professor of mechanical engineering
at the Naval Academy, thought it might be just as easy
to make engines that could filter and refine the oil
as it would to transform it in a lab.

So this semester, 10 midshipmen working on two teams
began rehabbing the engines of two diesel-powered
all-terrain vehicles, or go-karts.

John Gilligan, 22, of Dallas, Pa., said his team
followed the "KISS" rule - "keep it simple, stupid" -
in designing its engine. The Mids employed a series of
filters to siphon out the excess gunk in the oil, then
redesigned the exhaust system so the hot air can be
used to heat the cooking oil.

In general, vegetable oil is too viscous to work for
prolonged periods in diesel engines, which is why
biodiesel is so often created in a lab or home
processing kits. But when it's heated up, it develops
a thinner texture and becomes almost as good as
refined petroleum diesel.

So the midshipmen found a way to use exhaust fumes to
heat it and monitor the temperature with a digital
thermometer on the go-kart's dashboard. Once it's hot
enough, they switch the engine to work on the new
biodiesel.

On Tuesday Gilligan's team was putting the finishing
touches on the first prototype of their engine.

"It has to be ready to run by Friday, so we can rip it
apart and redo it," he said. "But it's been great to
make this. Everything seems theoretical until you can
actually put it together. This is what we've been
learning how to do for a long time."