Flutterby™! : Biodiesel

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2004-12-22 21:29:16.921527+00 by ebradway 12 comments

After spending three months on the road this summer in a 1994 Nissan Pathfinder and spending over $2000 on fuel to keep it moving, my wife and I decided to buy a new car. Intially we were tempted by the Honda Civic Hybrid. It actually rides alot nicer than the gasoline-only Civic because of the weight of the battery pack in the back and the virtually silent engine. However, the complexity of an automobile that uses two separate motors and recovers power from the brakes, was a little too much for me to stomach.

After a little more shopping around, we found that the Volkswagen Jetta TDi gets comparable mileage (42mpg city, 49mpg hwy), and does it all with an engine that is simpler than a gasoline engine - no ignition system! I had always wanted a diesel to convert to run on waste vegetable oil and a little research openned up my eyes quite a bit. What I thought would be a bizzarre experiment in automotive tinkering is actually much simpler!

First, a little history: Rudolf Diesel patented the Diesel engine in 1892 (yes, the technology has been around a loooooong time). The premise was to create an engine for farm implemneted that could be run on fuel made by the farmer. It ran on 100% peanut oil but could also run on any similar oil: corn, sunflower, rapeseed, even lard. It works this miracle by increasing the compression of the cylinders and doing away with the ignition (spark plugs, distributor, etc), using the compression to ignite the fuel. Although you can run a diesel on straight oil, some simple chemical processes can convert the oil to Biodiesel fuel. You can make Biodiesel fuel yourself from vegetable oil (even used oil from McD's) by mixing with lye and alcohol.

The real surprise came when I found out that Biodiesel is being made available, not by cooky shade-tree mechanics, but also by some pretty big players and has been in use by quite a few organizations. Furthermore, it's available at the pump in numerous places around the US, including several in Eastern Tennessee and even one in Chattanooga.

I now drive a VW Jetta Wagon with a diesel engine that gets over 40mpg and I can fuel it locally with a 20% biodiesel mixture, which currently sells for $1.899/gallon.

[ related topics: Invention and Design Chattanooga Automobiles Machinery Marriage ]

comments in ascending chronological order (reverse):

#Comment Re: made: 2004-12-23 14:35:02.585334+00 by: DaveP

The biggest problem with used frier oil is that, at least based on vehicles I've smelled using it, you'll smell like a rancid deep-frier as you drive.

#Comment Re: made: 2004-12-23 15:53:30.538592+00 by: ebradway

Is that really worse than the odor you current get from your car exhaust?

#Comment Re: made: 2004-12-23 17:00:09.884976+00 by: DaveP

Well, it's noticeable, especially when coming from a bus. Normal bus exhaust isn't all that pleasant, but it's something I'm used to. Having a bus go by and suddenly it smells like McDonald's is jarring.

#Comment Re: made: 2004-12-24 00:41:55.613024+00 by: meuon

My requirements were a little different, like having 4/all wheel drive, and just bought a Subaru Outback Sport. Still got my big F150 for when I need a truck, but the Subaru becomes a daily driver and with Nancy and I both working downtown and similiar hours, we share a ride some. It's only getting 28-30mpg but it's a blast to drive up and down Signal Mtn.

#Comment Re: made: 2004-12-24 06:10:41.371153+00 by: TheSHAD0W

Mmm, McDonalds...

#Comment Re: made: 2004-12-24 20:29:10.188148+00 by: Diane Reese

Is that really worse than the odor you current get from your car exhaust?
Yes. I have driven a hybrid for the past five years, and the exhaust (and attendant odor) is minimal.

... the complexity of an automobile that uses two separate motors and recovers power from the brakes, was a little too much for me to stomach.
Gee, I think it's pretty cool! If I could wave a wand and turn all vehicles into hybrids, I'd do it in an instant.

#Comment Re: made: 2004-12-25 01:43:26.112479+00 by: meuon

I understand Eric's aversion to complex systems and agree. The VW Diesel is a very very practical car, and his chances of of getting 250k+ miles out of it without a major issue from it are very good.

#Comment Re: made: 2004-12-29 17:13:24.898853+00 by: ebradway

Volkwagen has demonstrated a prototype Diesel Hybrid (just like a locomotive engine!) and Daimler-Chrysler is supposed to start selling a diesel hybrid in a couple years. Even the military is getting into the diesel hybrid with the new Humvee. Also, Daimler-Chrysler is adding a Mercedes-Benz CRD Diesel engine to the Jeep Liberty this Spring.

Here are some "advantages" to diesel vs. gasoline-hybrid:

  1. Diesel fuel produced from biomass is less toxic than table salt (you can drink it) and can be delivered in the same infrastructure as normal diesel. Methanol, a biomass gasoline replacement, is considerably more flammable than gasoline and more difficult to distribute.
  2. Diesel engines produce more torque at significatly lower RPMs than gasoline-hybrids (my Jetta diesel produces 177 ft-lbs of torque at 1800 rpm whereas the Honda Civic Hybrid produces only 87 ft-lbs of torque at 3300 rpm. This means the car accelerates in traffic with the engine firing fewer times per second - less fuel use and less emissions.
  3. The afore-mentioned complexity issues. My Jetta Wagon cost about $21,000, almost exactly the same as the Honda Civic Hybrid. However, Honda gets $6,000 from the US Government for every Hybrid they sell and they don't make any money on the Hybrid, so the car costs about $27,000 to manufacture. The Jetta Diesel is in limited supply (VW doesn't ship many to the US because of the relatively small market for diesels) and the dealers rarely give discounts. So VW and the dealer are making a nice profit at $21,000 without subsidies from the government. VW's official position is that they do not believe in building cars that they cannot make a profit on.

The real issue with diesel cars right now is the quality of diesel fuel available in the US. The crap you find at most pumps contains sulphur. In 2006, all diesel fuel will have sulphur removed. This will eliminate the "soot" you see coming from diesel powered vehicles and allow the use of a particulate filter. The filter traps NOx particles and periodically incinerates them. This removes the big smog component that has caused CA, MA, ME, NH, and PA to stop the sale of diesel powered cars (but you can still buy a diesel Hummer or big pickup - go figure).

#Comment Re: made: 2004-12-30 00:07:32.976629+00 by: Dan Lyke

Got a question on the whole biomass thing: My impression is that this is something that's economical right now mainly because of the oil as a waste product of frying, and that the base materials come from corn, which is probably as heavily subsidized a product as oil, at least in the U.S.

What happens when we hit the critical mass of converted diesels? Not that it isn't a good idea right now, but will it scale to the whole populace, or is this something that'll only work while it's a niche?

#Comment Re: made: 2004-12-30 01:51:56.542182+00 by: Larry Burton

Looking at the amount of high fructose corn syrup that we currently consume... and shouldn't.... I think it would give all that corn some place else to go at possibly a little higher price than into our foods. I believe corn oil is fairly cheap and if the processing doesn't have to be for human consumption I believe it could be cheaper still. Oh, and since it doesn't have to be fit for human consumption there may be other plant sources for this oil that we aren't currently producing that might be cheaper still than what we are producing now.

I wonder how hemp oil would work in a diesel?

#Comment Re: made: 2004-12-30 02:09:36.64282+00 by: Dan Lyke

Larry, the image of hippies chasing buses down Haight Street was one I could have skipped.

#Comment Re: made: 2005-01-12 00:20:05.704233+00 by: ebradway

Sorry it's been so long. I've been on vacation...

Biodiesel, at least in the incarnation that I use, is generally produced from raw soybeans, not WVO (waste vegetable oil). Some folks do make their own diesel fuel from WVO, but the majority of Biodiesel comes from crops and works in all diesel engines without modification. What I buy at the pump here in Chattanooga is a blend of 20% soybean Biodiesel with 80% dino-diesel. I get slightly better fuel economy, smoother operation, and fewer emissions. I can't run 100% Biodiesel in Chattanooga (in Winter at least) without fuel-line heaters, which are common and inexpensive, because Biodiesel clouds at about 50 degrees F and begins to gel around 30 degrees. The B20 I use now is good to about -20 degress F.

In Europe, Biodiesel is made from rapeseed. Any vegetable oil can be used. Soybean is popular in the US because it is common. Corn would work just as well. Hemp would be excellent too.

BTW, the folks at HempCar.org claim that only 6% of US land needs to be farmed with hemp (without displacing any food crops) to supply 100% of our energy needs. I haven't seen any other reports that directly outline the how much land is needed to meet the energy needs of the US.