Amazing: the US automobile industry discovers the Diesel engine...
mo at ccr.org
Thu Apr 26 20:39:17 CDT 2012
there are several problems with corn-based ethanol as a fuel.
you mentioned the energy density problem, but another important one
is that it is extremely unkind to modern composites. E-X for X>10 will
the resin matrix in the most common kinds of fiberglass and consequently
destroy the engine attempting to run on the resulting mixture from a
composite fuel tank. it also does this to some standard liners in metal
ethanol also attracts water vigorously and the mixture of ethanol and
water is quite
corrosive to many alloys used in engines. (methanol is much worse.)
the biggest problem, however, is that production of ethanol is net
the energy that goes into making it is more than the energy that will be
by the combustion. the mythical cellulosic ethanol has never been
commercial scale for less than the unit price of gasoline containing far
available energy. many efforts to produce catalysts or enzymes to make
cellulosic ethanol viable have been funded to no useful effect.
without massive subsidies, ethanol as a fuel is not economically viable.
CNG (compressed natural gas) or liquid fuels made from natural gas
are much better fuel choices, and with the price of natural gas plummeting,
ethanol doesn't stand a chance.
On 4/26/12 3:20 PM, Phil wrote:
> Diesel engines have long been touted in the UK as "green" and "non-polluting" simply because they don't contain tetraethyl lead and, eventually, the CO emissions were brought under control. However, the hydrocarbon emissions they produce are filthy and a great deal more hazardous to public health than unleaded petrol. Ethanol is very clean by comparison and burns very efficiently to carbon dioxide and water - mere greenhouse gases - but the energy-per-gallon figure is a lot less than diesel or petrol. It also makes little sense to have constantly to toss up the 'economic' advantages of whether to convert a grain crop into food or fuel - but probably inevitable in the long term.
> Phil M1GWZ
> On 26 Apr 2012, at 06:20, Robert Stratton wrote:
>> I'm with you, gents. I was reading news about Virginia debating whether to renew the HOV waiver for hybrids and was thinking that if they really cared about fuel usage, they'd include modern diesels in the waiver.
>> I would suggest you get a pre-2007 though. (I love my 2005 CDI and its 500 Nm torque) The new ones ("Bluetec") have a urea solution tank and if it runs dry the engine nags you and then eventually will refuse to start at all. That's a little too much micromanagement for my taste.
>> --Bob S.
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