Re: Marine diesels, turbines, and alternate fuels?
- From: "Jack Linthicum" <jacklinthicum@xxxxxxxxxxxxx>
- Date: 17 Jul 2006 08:26:34 -0700
Peter Skelton wrote:
On 16 Jul 2006 21:22:00 -0700, "David E. Powell"
<David_Powell3006@xxxxxxx> wrote:
I was wondering... considering the questions that people ask these daysTHere's a thriving little industry converting restaurant waste to
about alternate fuels, I was wondering how some of the ones proposed
would do in marine engines? I know that some turbines can burn
different fuel types, so I was wondering if the kind of Ethanol Brazil
seems to be fond of would work in one. Then again, Marine turbines
often run on jet fuel, kerosene, which is pretty heavy.
Another alternate fuel some folks use in cars is recycled vegetable
oil. If it could be collected, and burned in diesels. At least one fast
food chain uses their old fry oil in their truck fleet. However,
diesels must be modified to use it and the engine must be warmed up on
regular diesel before it can be switched over to the vegetable oil for
cruise. Not sure if a marine diesel or turbine's fuel system could take
that stuff, or if enough could be collected effectively to fuel a ship
at all.
So, might either fuel pop up in the future if fuel prices stay around
these levels? The infrastructure investment costs would be pretty big,
and considering the amounts needed for just a few of a ship's bunkers,
it would need a good source, like a serious effort among vegetable oil
sources or in using some kind of agricultural waste, like crops which
had spoiled. And it would be a supply with spikes and lows. It would be
a portion of fuels used, not the full measure.
biodeisel and another selling do-it yourself equipment.
Peter Skelton
Better lock in a long-term contract then, because ethanol can only
supply 12% of fuel needs. Even Soy-diesel won't hack it. Despite the
seeming humor in the statement President Bush's switch grass and other
naturally sown sources are more promising. But promises aside the idea
of taking our food and turning it into fuel, 300 million acres of
switchgrass would not be enough ethanol for the nearly double needs of
2025.
Graphic shows bushels of corn used for ethanol production. (AP Graphic)
(AP) -- Ethanol is far from a cure-all for the nation's energy
problems. It's not as environmentally friendly as some supporters claim
and would supply only 12 percent of U.S. motoring fuel - even if every
acre of corn were used.
A number of researchers, the latest in a report Monday, are warning
about exaggerated expectations that ethanol could dramatically change
America's dependence on foreign oil by shifting motorists away from
gasoline.
As far as alternative fuels are concerned, biodiesel from soybeans is
the better choice compared with corn-produced ethanol, University of
Minnesota researchers concluded in an analysis Monday.
But "neither can replace much petroleum without impacting food
supplies," the researchers concluded in the paper published in the
Proceedings of the National Academy of Sciences.
The paper said development of nonfood materials such as switchgrass,
prairie grasses and woody plants to produce cellulosic ethanol would be
a major improvement with greater energy output and lower environmental
impacts.
But creation of cellulosic ethanol remains in the laboratory research
stage. And even nonfood sources of ethanol would fall far short of
replacing gasoline, most researchers agree.
Biofuels such as ethanol are "not a practical long-term solution," and
their widespread use - even from nonfood crop sources - could have a
"devastating" impact on agriculture, two researchers at the Magleve
Research Center of the Polytechnic University of New York, argued
recently.
"Ethanol from 300 million acres of switchgrass still could not supply
our present gasoline and diesel consumption, which is projected to
double by 2025," the researchers, James Jordan and James Powell, wrote
in an op-ed article in the Washington Post. "The agricultural effects
of such a large-scale program would be devastating."
In addition to a reduction in soil fertility by not plowing wastes back
into the ground, there is concern that using corn and soybeans for
ethanol would create competition for food crops.
But Geoff Cooper, a spokesman for the National Corn Growers
Association, calls suggestions that the growth of ethanol will
jeopardize food supplies as "fear mongering."
"There's absolutely no shortage of corn," said Cooper. He said demand
for corn for livestock feed has been flat and that increased production
and expected higher yields per acre will provide plenty of corn to meet
all needs.
In a frenzy to respond to public outcries about high gasoline and crude
oil prices, members of Congress as well as the Bush administration have
embraced ethanol as the alternative to gasoline to help move the
country closer to energy independence.
Ethanol, virtually all of it made from corn in this country, also has
been touted as the "green" alternative motor fuel with a push to make
it more widely available not only as a 10 percent additive but with an
85 percent blend with gasoline.
"We definitely believe that biofuels (such as ethanol) have a
significant potential," said Jason Hill, lead author of the University
of Minnesota study. But he added that ethanol should not be viewed as
"a savior" to our energy problems and its rapid expansion as a motor
fuel has its drawbacks, especially if it is dependent on food crops
such as corn and soybeans as feedstock.
If every acre of corn were used for ethanol, it would replace only 12.3
percent of the gasoline used in this country, Hill's study said, adding
that the energy gains of corn-produced ethanol are only modest and the
environmental impacts significant.
As a motor fuel, ethanol from corn produces a modest 25 percent more
energy than is consumed - including from fossil fuels - in growing the
corn, converting it into ethanol and shipping it for use in gasoline.
While often touted as a "green" environmentally friendly fuel,
corn-based ethanol's life cycle environmental impacts are mixed as
best, the researchers said.
Compared with gasoline, it produces 12 percent less "greenhouse" gasses
linked to global warming, according to the study. But the researchers
also said it has environmental drawbacks, including "markedly greater"
releases of nitrogen, phosphorous and pesticides into waterways as
runoff from corn fields. Ethanol, especially at higher concentrations
in gasoline, also produce more smog-causing pollutants than gasoline
per unit of energy burned, the researchers said.
"There's a lot of green in the money that's going into ethanol, but
perhaps not so much green is coming out as far as the environment,"
said Hill, the lead author, in a telephone interview.
The ethanol industry says there's little new in the University of
Minnesota study.
"Everyone in the industry recognizes that there is a limit on how much
ethanol you can produce from corn," said Matt Hartwig, a spokesman for
the Renewable Fuels Association, which represents ethanol producers.
"Nobody is saying that ethanol is the silver bullet that is going to
solve all our energy problems. It's going to take a whole host of
technologies. ... But ethanol and other biofuels play a very critical
role."
He said the University of Minnesota study is only the latest to
conclude that ethanol produces more energy than it consumes. "More
importantly, there is a significant reduction in petroleum use with
ethanol," he added.
Last year about 14 percent of the corn crop went to ethanol, compared
with 11 percent four years ago. This year the amount of corn for
ethanol could be nearly one in every five bushels grown, or 19 percent,
according to Agriculture Department estimates.
The Corn Growers Association says that by 2015 a third of all the corn
grown - or 5.5 billion bushels - likely will be for ethanol. The Energy
Department says it has a goal of 30 percent of the fuel used by
motorists to be ethanol - both corn-based and cellulosic - by 2030.
http://www.physorg.com/news71833070.html
.
- References:
- Marine diesels, turbines, and alternate fuels?
- From: David E. Powell
- Re: Marine diesels, turbines, and alternate fuels?
- From: Peter Skelton
- Marine diesels, turbines, and alternate fuels?
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